This report provides the results of a detailed Level II analysis of scour potential at structure \nSPRICYBRIG0043 on Bridge Street crossing the Black River, Springfield, Vermont \n(figures 1–8). A Level II study is a basic engineering analysis of the site, including a \nquantitative analysis of stream stability and scour (U.S. Department of Transportation, \n1993). Results of a Level I scour investigation also are included in Appendix E of this \nreport. A Level I investigation provides a qualitative geomorphic characterization of the \nstudy site. Information on the bridge, gleaned from Vermont Agency of Transportation \n(VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is \nfound in Appendix D.
\nThe site is in the New England Upland section of the New England physiographic province \nin southeastern Vermont. The 191-mi2\n drainage area is a predominantly rural and forested \nbasin. In the vicinity of the study site, the surface cover consist of some grass, buildings, \nand pavement. The immediate banks are covered with trees, shrubs and brush.
\nIn the study area, the Black River has an incised channel with a slope of approximately \n0.001 ft/ft, an average channel top width of 156 ft and an average bank height of 14 ft. The \nchannel bed material is predominantly cobbles with a median grain size (D50) of 90.7 mm \n(0.298 ft). The geomorphic assessment at the time of the Level I and Level II site visit on \nSeptember 19, 1996, indicated that the reach was stable.
\nThe Bridge Street crossing of the Black River is a 123-foot-long, two-lane bridge consisting \nof one 119-foot steel-beam span (Vermont Agency of Transportation, written \ncommunication, March 30, 1995). The bridge is supported by vertical, concrete abutments \nwith wingwalls. The channel is skewed approximately 20 degrees to the opening while the \nopening-skew-to-roadway is 20 degrees.
\nThe scour protection measures at the site were type-2 stone fill (less than 36 inches \ndiameter) along the downstream left bank and the downstream left wingwall. There was \nalso type-1 stone fill (less than 12 inches diameter) along right abutment and the \ndownstream right wingwall. There is a nine foot tall concrete wall along the downstream \nright bank to 89 feet downstream of the bridge. Additional details describing conditions at \nthe site are included in the Level II Summary and Appendices D and E.
\nScour depths and recommended rock rip-rap sizes were computed using the general \nguidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995). \nTotal scour at a highway crossing is comprised of three components: 1) long-term \nstreambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction \nin flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and \nabutments). Total scour is the sum of the three components. Equations are available to \ncompute depths for contraction and local scour and a summary of the results of these \ncomputations follows.
\nThere was no computed contraction scour. Left abutment scour ranged from 9.9 to 11 ft. \nThe worst-case left abutment scour occurred at the 100-year discharge. Right abutment \nscour ranged from 6.5 to 11.2 ft. The worst-case right abutment scour occurred at the 500-\nyear discharge. Additional information on scour depths and depths to armoring are \nincluded in the section titled “Scour Results”. Scoured-streambed elevations, based on the \ncalculated scour depths, are presented in tables 1 and 2. A cross-section of the scour \ncomputed at the bridge is presented in figure 8. Scour depths were calculated assuming an \ninfinite depth of erosive material and a homogeneous particle-size distribution.
\nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr97227","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Ivanoff, M.A., and Medalie, L., 1997, Level II scour analysis for Bridge 43 (SPRICYBRIG0043) on Bridge Street, crossing the Black River, Springfield, Vermont: U.S. Geological Survey Open-File Report 97-227, iv, 48 p., https://doi.org/10.3133/ofr97227.","productDescription":"iv, 48 p.","numberOfPages":"53","costCenters":[],"links":[{"id":169719,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97227.GIF"},{"id":279776,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0227/report.pdf"}],"scale":"25000","country":"United States","state":"Vermont","city":"Springfield","otherGeospatial":"Black River","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.5,43.25 ], [ -72.5,43.375 ], [ -72.25,43.375 ], [ -72.25,43.25 ], [ -72.5,43.25 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a61c3","contributors":{"authors":[{"text":"Ivanoff, Michael A.","contributorId":27105,"corporation":false,"usgs":true,"family":"Ivanoff","given":"Michael","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":240464,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Medalie, Laura 0000-0002-2440-2149 lmedalie@usgs.gov","orcid":"https://orcid.org/0000-0002-2440-2149","contributorId":3657,"corporation":false,"usgs":true,"family":"Medalie","given":"Laura","email":"lmedalie@usgs.gov","affiliations":[{"id":466,"text":"New England Water Science Center","active":true,"usgs":true}],"preferred":true,"id":240463,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49909,"text":"ofr97226 - 1997 - Level II scour analysis for Bridge 12 (HUNTTH00010012) on Town Highway 001, crossing Brush Brook, Huntington, Vermont","interactions":[],"lastModifiedDate":"2014-01-06T11:07:06","indexId":"ofr97226","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-226","title":"Level II scour analysis for Bridge 12 (HUNTTH00010012) on Town Highway 001, crossing Brush Brook, Huntington, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nHUNTTH00010012 on Town Highway 1 crossing Brush Brook, Huntington, Vermont \n(figures 1–9). A Level II study is a basic engineering analysis of the site, including a \nquantitative analysis of stream stability and scour (U.S. Department of Transportation, \n1993). Results of a Level I scour investigation also are included in Appendix E of this \nreport. A Level I investigation provides a qualitative geomorphic characterization of the \nstudy site. Information on the bridge, gleaned from Vermont Agency of Transportation \n(VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is \nfound in Appendix D.
\nIn August 1976, Hurricane Belle caused flooding at this site which resulted in road and \nbridge damage (figures 7-8). This was approximately a 25-year flood event based on flood-\nfrequency data contained in the Flood Insurance Study for the Town of Huntington (U.S. \nDepartment of Housing and Urban Development, 1978).
\nThe site is in the Green Mountain section of the New England physiographic province in \ncentral Vermont. The 9.19-mi2\n drainage area is in a predominantly rural and forested basin. \nIn the vicinity of the study site, the surface cover is pasture while the immediate banks have \nsome woody vegetation.
\nIn the study area, the Brush Brook has a sinuous channel with a slope of approximately 0.02 \nft/ft, an average channel top width of 62 ft and an average bank height of 5 ft. The channel \nbed material ranges from gravel to cobble with a median grain size (D50) of 100.0 mm \n(0.328 ft). The geomorphic assessment at the time of the Level I and Level II site visit on \nJune 25, 1996, indicated that the reach was stable.
\nThe Town Highway 1 crossing of Brush Brook is a 64-ft-long, two-lane bridge consisting of \none 62-foot steel-stringer span (Vermont Agency of Transportation, written \ncommunication, November 30, 1995). The bridge is supported by vertical, concrete \nabutments with wingwalls. The channel is skewed approximately 10 degrees to the opening \nwhile the opening-skew-to-roadway is 6 degrees.
\nChannel scour 2.2 ft deeper than the mean thalweg depth was observed along the upstream \nright bank and along the base of the spill-through protection for the right abutment during \nthe Level I assessment. Scour protection measured at the site was type-2 stone fill (less \nthan 36 inches diameter) along the upstream left and right banks and in front of all four \nwingwalls. In front of the abutments, there was type-3 stone fill (less than 48 inches \ndiameter) forming a spill-through slope. Additional details describing conditions at the site \nare included in the Level II Summary and Appendices D and E.
\nScour depths and recommended rock rip-rap sizes were computed using the general \nguidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995). \nTotal scour at a highway crossing is comprised of three components: 1) long-term \nstreambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction \nin flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and \nabutments). Total scour is the sum of the three components. Equations are available to \ncompute depths for contraction and local scour and a summary of the results of these \ncomputations follows.
\nThere was no computed contraction scour for any modelled flow. Abutment scour ranged \nfrom 1.4 to 2.8 ft. The worst-case abutment scour occurred at the 500-year discharge. \nAdditional information on scour depths and depths to armoring are included in the section \ntitled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, \nare presented in tables 1 and 2. A cross-section of the scour computed at the bridge is \npresented in figure 9. Scour depths were calculated assuming an infinite depth of erosive \nmaterial and a homogeneous particle-size distribution.
\nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr97226","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Burns, R.L., and Wild, E.C., 1997, Level II scour analysis for Bridge 12 (HUNTTH00010012) on Town Highway 001, crossing Brush Brook, Huntington, Vermont: U.S. Geological Survey Open-File Report 97-226, iv, 49 p., https://doi.org/10.3133/ofr97226.","productDescription":"iv, 49 p.","numberOfPages":"54","costCenters":[],"links":[{"id":169718,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97226.GIF"},{"id":279777,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0226/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Huntington","otherGeospatial":"Brush Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -73.0,44.25 ], [ -73.0,44.375 ], [ -72.875,44.375 ], [ -72.875,44.25 ], [ -73.0,44.25 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b1ae4b07f02db6a83b3","contributors":{"authors":[{"text":"Burns, Ronda L.","contributorId":71602,"corporation":false,"usgs":true,"family":"Burns","given":"Ronda","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":240462,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Wild, Emily C. 0000-0001-6157-7629 ecwild@usgs.gov","orcid":"https://orcid.org/0000-0001-6157-7629","contributorId":1810,"corporation":false,"usgs":true,"family":"Wild","given":"Emily","email":"ecwild@usgs.gov","middleInitial":"C.","affiliations":[{"id":5081,"text":"Libraries","active":false,"usgs":true}],"preferred":false,"id":240461,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49908,"text":"ofr97225 - 1997 - Level II scour analysis for Bridge 27 (ANDOTH00290027) on Town Highway 29, crossing Middle Branch Williams River, Andover, Vermont","interactions":[],"lastModifiedDate":"2014-01-05T13:56:45","indexId":"ofr97225","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-225","title":"Level II scour analysis for Bridge 27 (ANDOTH00290027) on Town Highway 29, crossing Middle Branch Williams River, Andover, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nANDOTH00290027 on Town Highway 29 crossing the Middle Branch Williams River, \nAndover, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, \nincluding a quantitative analysis of stream stability and scour (U.S. Department of \nTransportation, 1993). Results of a Level I scour investigation also are included in \nAppendix E of this report. A Level I investigation provides a qualitative geomorphic \ncharacterization of the study site. Information on the bridge, gleaned from Vermont Agency \nof Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II \nanalyses and is found in Appendix D.
\nThe site is in the Green Mountain section of the New England physiographic province in \ncentral Vermont. The 12.7-mi2\n drainage area is in a predominantly rural and forested basin. \nIn the vicinity of the study site, the surface cover is pasture on the left bank upstream of the \nbridge while the immediate bank has woody vegetation. The surface cover on the upstream \nright bank is forest. Downstream of the bridge the left bank is pasture and the right bank \nhas woody vegetation.
\nIn the study area, the Middle Branch Williams River has an incised, straight channel with a \nslope of approximately 0.009 ft/ft, an average channel top width of 63 ft and an average \nbank height of 5 ft. The channel bed material ranges from sand to cobble with a median \ngrain size (D50) of 64.7 mm (0.212 ft). The geomorphic assessment at the time of the Level \nI and Level II site visit on September 10, 1996, indicated that the reach was stable.
\nThe Town Highway 29 crossing of the Middle Branch Williams River is a 34-ft-long, two-\nlane bridge consisting of one 32-foot steel-beam span (Vermont Agency of Transportation, \nwritten communication, April 5, 1995). The bridge is supported by vertical, concrete \nabutments with wingwalls. The channel is skewed approximately 25 degrees to the opening \nwhile the opening-skew-to-roadway is 0 degrees.
\nA scour hole 1.5 ft deeper than the mean thalweg depth was observed along the left \nabutment during the Level I assessment. Scour protection measures at the site include type-\n2 stone fill (less than 36 inches diameter) along the upstream right bank and downstream \nleft bank and around the upstream left and right wingwalls. Type- 3 stone fill (less than 48 \ninches diameter) is located along the base of the left abutment in the scour hole, at the end \nof the downstream left wingwall and along the upstream left bank. Additional details \ndescribing conditions at the site are included in the Level II Summary and Appendices D \nand E.
\nScour depths and recommended rock rip-rap sizes were computed using the general \nguidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995). \nTotal scour at a highway crossing is comprised of three components: 1) long-term \nstreambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction \nin flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and \nabutments). Total scour is the sum of the three components. Equations are available to \ncompute depths for contraction and local scour and a summary of the results of these \ncomputations follows.
\nContraction scour for all modelled flows ranged from 0.4 to 0.9 ft. The worst-case \ncontraction scour occurred at the incipient-overtopping discharge and the 100-year \ndischarge. Abutment scour ranged from 10.7 to 13.6 ft. The worst-case abutment scour \noccurred at the 500-year discharge. Additional information on scour depths and depths to \narmoring are included in the section titled “Scour Results”. Scoured-streambed elevations, \nbased on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the \nscour computed at the bridge is presented in figure 8. Scour depths were calculated \nassuming an infinite depth of erosive material and a homogeneous particle-size distribution.
\nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr97225","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Burns, R.L., and Wild, E.C., 1997, Level II scour analysis for Bridge 27 (ANDOTH00290027) on Town Highway 29, crossing Middle Branch Williams River, Andover, Vermont: U.S. Geological Survey Open-File Report 97-225, iv, 50 p., https://doi.org/10.3133/ofr97225.","productDescription":"iv, 50 p.","numberOfPages":"55","costCenters":[],"links":[{"id":169646,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97225.GIF"},{"id":279775,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0225/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Andover","otherGeospatial":"Middle Branch Williams River","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.75,43.25 ], [ -72.75,43.375 ], [ -72.625,43.375 ], [ -72.625,43.25 ], [ -72.75,43.25 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b1ae4b07f02db6a7ffe","contributors":{"authors":[{"text":"Burns, Ronda L.","contributorId":71602,"corporation":false,"usgs":true,"family":"Burns","given":"Ronda","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":240460,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Wild, Emily C. 0000-0001-6157-7629 ecwild@usgs.gov","orcid":"https://orcid.org/0000-0001-6157-7629","contributorId":1810,"corporation":false,"usgs":true,"family":"Wild","given":"Emily","email":"ecwild@usgs.gov","middleInitial":"C.","affiliations":[{"id":5081,"text":"Libraries","active":false,"usgs":true}],"preferred":false,"id":240459,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":50009,"text":"ofr97773 - 1997 - Level II scour analysis for Bridge 38 (JERITH0020038) on Town Highway 20, crossing the Lee River, Jericho, Vermont","interactions":[],"lastModifiedDate":"2016-08-25T14:51:05","indexId":"ofr97773","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-773","title":"Level II scour analysis for Bridge 38 (JERITH0020038) on Town Highway 20, crossing the Lee River, Jericho, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure JERITH00200038 on Town Highway 20 crossing the Lee River, Jericho, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including a quantitative analysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of a Level I scour investigation also are included in Appendix E of this report. A Level I investigation provides a qualitative geomorphic characterization of the study site. Information on the bridge, obtained from Vermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is found in Appendix D.
The site is in the Green Mountain section of the New England physiographic province and the Champlain section of the St. Lawrence physiographic province in northwestern Vermont. The 12.9-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover on the upstream and downstream right overbank is pasture while the immediate banks have dense woody vegetation. The surface cover on the upstream and downstream left overbank is forested.
In the study area, the Lee River has an incised, sinuous channel with a slope of approximately 0.02 ft/ft, an average channel top width of 89 ft and an average bank height of 14 ft. The channel bed material ranges from sand to boulder with a median grain size (D50) of 45.9 mm (0.151 ft). The geomorphic assessment at the time of the Level I and Level II site visit on July 2, 1996, indicated that the reach was stable.
The Town Highway 20 crossing of the Lee River is a 49-ft-long, one-lane bridge consisting of a steel through truss span (Vermont Agency of Transportation, written communication, December 12, 1995). The opening length of the structure parallel to the bridge face is 44 ft. The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 10 degrees to the opening while the computed opening-skew-toroadway is 5 degrees.
A scour hole 1 ft deeper than the mean thalweg depth was observed in the center of the channel during the Level I assessment. Scour countermeasures at the site include type-1 stone fill (less than 12 inches diameter) at the downstream left road embankment. Type-2 stone fill (less than 36 inches diameter) protects the upstream left wingwall, the upstream and downstream right wingwalls and the upstream end of the right abutment. Type-3 stone fill (less than 48 inches diameter) protects the left abutment. Additional details describing conditions at the site are included in the Level II Summary and Appendices D and E.
Scour depths and recommended rock rip-rap sizes were computed using the general guidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995) for the 100- and 500-year discharges. Total scour at a highway crossing is comprised of three components: 1) long-term streambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is the sum of the three components. Equations are available to compute depths for contraction and local scour and a summary of the results of these computations follows.
Contraction scour for all modelled flows was zero. Abutment scour ranged from 4.9 to 10.7 ft. The worst-case abutment scour occurred at the 500-year discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution.
It is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, computed scour depths are evaluated in combination with other information including (but not limited to) historical performance during flood events, the geomorphic stability assessment, existing scour protection measures, and the results of the hydraulic analyses. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr97773","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Wild, E.C., and Degnan, J.R., 1997, Level II scour analysis for Bridge 38 (JERITH0020038) on Town Highway 20, crossing the Lee River, Jericho, Vermont: U.S. Geological Survey Open-File Report 97-773, iv, 48 p., https://doi.org/10.3133/ofr97773.","productDescription":"iv, 48 p.","numberOfPages":"53","costCenters":[],"links":[{"id":176807,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97773.PNG"},{"id":279670,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0773/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Jericho","otherGeospatial":"Lee River","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.75,43.5 ], [ -72.75,43.625 ], [ -72.625,43.625 ], [ -72.625,43.5 ], [ -72.75,43.5 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a6271","contributors":{"authors":[{"text":"Wild, Emily C. 0000-0001-6157-7629 ecwild@usgs.gov","orcid":"https://orcid.org/0000-0001-6157-7629","contributorId":1810,"corporation":false,"usgs":true,"family":"Wild","given":"Emily","email":"ecwild@usgs.gov","middleInitial":"C.","affiliations":[{"id":5081,"text":"Libraries","active":false,"usgs":true}],"preferred":false,"id":240628,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Degnan, James R. 0000-0002-5665-9010 jrdegnan@usgs.gov","orcid":"https://orcid.org/0000-0002-5665-9010","contributorId":498,"corporation":false,"usgs":true,"family":"Degnan","given":"James","email":"jrdegnan@usgs.gov","middleInitial":"R.","affiliations":[{"id":466,"text":"New England Water Science Center","active":true,"usgs":true},{"id":405,"text":"NH/VT office of New England Water Science Center","active":true,"usgs":true}],"preferred":true,"id":240627,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49913,"text":"ofr97341 - 1997 - Level II scour analysis for Bridge 2 (BENNCYPARK0002) on Park Street, crossing Furnace Brook, Bennington, Vermont","interactions":[],"lastModifiedDate":"2014-01-05T13:22:53","indexId":"ofr97341","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-341","title":"Level II scour analysis for Bridge 2 (BENNCYPARK0002) on Park Street, crossing Furnace Brook, Bennington, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nBENNCYPARK0002 on the Park Street crossing of Furnace Brook, Bennington, Vermont \n(figures 1–8). A Level II study is a basic engineering analysis of the site, including a \nquantitative analysis of stream stability and scour (U.S. Department of Transportation, \n1993). Results of a Level I scour investigation also are included in Appendix E of this \nreport. A Level I investigation provides a qualitative geomorphic characterization of the \nstudy site. Information on the bridge, gleaned from Vermont Agency of Transportation \n(VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is \nfound in Appendix D.
\nThe site is in the Green Mountain section of the New England physiographic province in \nsouthwestern Vermont. The 12.8-mi2\n drainage area is a predominantly rural and forested \nbasin. The bridge site is located within an urban setting in the Town of Bennington with \nbuildings, homes, lawns, and pavement on the overbanks.
\nIn the study area, Furnace Brook has a mildly sinuous channel located on a delta and has a \nslope of approximately 0.01 ft/ft, an average channel top width of 35 ft and an average bank \nheight of 4 ft. The predominant channel bed materials are gravel and cobble with a median \ngrain size (D50) of 58.4 mm (0.192 ft). The geomorphic assessment at the time of the Level \nI and Level II site visit on August 6, 1996, indicated that the reach was unstable. However, \nin the immediate vicinity of the bridge the reach has been stabilized with bank protection. \nUpstream of the protection, there is bank cutting and channel scour.
\nThe Park Street crossing of Furnace Brook is a 29-ft-long, two-lane bridge consisting of one \n26-foot concrete span (Vermont Agency of Transportation, written communication, \nDecember 14, 1995). The width of the bridge opening parallel to the downstream bridge \nface is 25.3 feet. The bridge is supported by vertical, concrete abutments with no wingwalls. \nThe upstream channel is skewed approximately 45 degrees to the opening while the \nopening-skew-to-roadway is 10 degrees.
\nScour countermeasures at the site include type-2 stone fill (less than 36 inches diameter) on \nthe right banks upstream and downstream of the bridge and type-3 stone fill (less than 48 \ninches diameter) on the upstream left bank. Additional details describing conditions at the \nsite are included in the Level II Summary and Appendices D and E.
\nScour depths and recommended rock rip-rap sizes were computed using the general \nguidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995). \nTotal scour at a highway crossing is comprised of three components: 1) long-term \nstreambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction \nin flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and \nabutments). Total scour is the sum of the three components. Equations are available to \ncompute depths for contraction and local scour and a summary of the results of these \ncomputations follows.
\nThere was no contraction scour computed for any of the modelled flows. Computed left \nabutment scour ranged from 2.5 to 5.6 ft. with the worst-case scour occurring at the 500-\nyear discharge. Computed right abutment scour ranged from 5.6 to 8.4 ft. with the worst-\ncase scour also occurring at the 100-year discharge. Additional information on scour depths \nand depths to armoring are included in the section titled “Scour Results”. Scoured-\nstreambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. \nA cross-section of the scour computed at the bridge is presented in figure 8. Scour depths \nwere calculated assuming an infinite depth of erosive material and a homogeneous particle-\nsize distribution.
\nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr97341","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Olson, S.A., 1997, Level II scour analysis for Bridge 2 (BENNCYPARK0002) on Park Street, crossing Furnace Brook, Bennington, Vermont: U.S. Geological Survey Open-File Report 97-341, iv, 51 p., https://doi.org/10.3133/ofr97341.","productDescription":"iv, 51 p.","numberOfPages":"56","costCenters":[],"links":[{"id":169722,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97341.GIF"},{"id":279772,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0341/report.pdf"}],"country":"United States","state":"Vermont","city":"Bennington","otherGeospatial":"Furnace Brook","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b1ae4b07f02db6a81a3","contributors":{"authors":[{"text":"Olson, Scott A. 0000-0002-1064-2125 solson@usgs.gov","orcid":"https://orcid.org/0000-0002-1064-2125","contributorId":2059,"corporation":false,"usgs":true,"family":"Olson","given":"Scott","email":"solson@usgs.gov","middleInitial":"A.","affiliations":[{"id":405,"text":"NH/VT office of New England Water Science Center","active":true,"usgs":true}],"preferred":true,"id":240467,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":49907,"text":"ofr97218 - 1997 - Level II scour analysis for Bridge 30 (NEWFVT00300013) on Vermont Highway 30, crossing Smith Brook, Newfane, Vermont","interactions":[],"lastModifiedDate":"2014-01-06T14:30:40","indexId":"ofr97218","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-218","title":"Level II scour analysis for Bridge 30 (NEWFVT00300013) on Vermont Highway 30, crossing Smith Brook, Newfane, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nNEWFVT00300013 on State Route 30 crossing Smith Brook, Newfane, Vermont (figures \n1–8). A Level II study is a basic engineering analysis of the site, including a quantitative \nanalysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of \na Level I scour investigation also are included in Appendix E of this report. A Level I \ninvestigation provides a qualitative geomorphic characterization of the study site. \nInformation on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) \nfiles, was compiled prior to conducting Level I and Level II analyses and is found in \nAppendix D.
\nThe site is in the New England Upland section of the New England physiographic province \nin southeastern Vermont. The 9.38-mi2\n drainage area is in a predominantly rural and \nforested basin. In the vicinity of the study site, the surface cover is grass and shrubs except \nfor the upstream right bank which is forested.
\nIn the study area, Smith Brook has an incised, sinuous channel with a slope of \napproximately 0.01 ft/ft, an average channel top width of 53 ft and an average bank height \nof 5 ft. The channel bed material is predominantly cobbles with a median grain size (D50) of \n79.5 mm (0.261 ft). The geomorphic assessment at the time of the Level I and Level II site \nvisit on August 20, 1996, indicated that the reach was stable.
\nThe State Route 30 crossing of Smith Brook is a 69-ft-long, two-lane bridge consisting of \none 66-foot steel-beam span (Vermont Agency of Transportation, written communication, \nMarch 30, 1995). The bridge is supported by vertical, concrete abutments with wingwalls. \nThe channel is skewed approximately 45 degrees to the opening while the opening-skew-to-\nroadway is 55 degrees.
\nThe scour protection measures at the site were type-1 stone fill (less than 12 inches \ndiameter) along the upstream right bank. There was also type-2 stone fill (less than 36 \ninches diameter) along the upstream left bank. A stone wall extends to 72 feet upstream \nfrom the end of the upstream left wingwall. There is another stone wall along the upstream \nright bank. Additional details describing conditions at the site are included in the Level II \nSummary and Appendices D and E.
\nScour depths and recommended rock rip-rap sizes were computed using the general \nguidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995). \nTotal scour at a highway crossing is comprised of three components: 1) long-term \nstreambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction \nin flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and \nabutments). Total scour is the sum of the three components. Equations are available to \ncompute depths for contraction and local scour and a summary of the results of these \ncomputations follows.
\nContraction scour for all modelled flows ranged from 0.0 to 0.8 ft. The worst-case \ncontraction scour occurred at the 500-year discharge. Abutment scour ranged from 14.4 to \n18.2 ft. The worst-case abutment scour occurred at the 500-year discharge. Additional \ninformation on scour depths and depths to armoring are included in the section titled “Scour \nResults”. Scoured-streambed elevations, based on the calculated scour depths, are presented \nin tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure \n8. Scour depths were calculated assuming an infinite depth of erosive material and a \nhomogeneous particle-size distribution.
\nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr97218","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Ivanoff, M.A., and Medalie, L., 1997, Level II scour analysis for Bridge 30 (NEWFVT00300013) on Vermont Highway 30, crossing Smith Brook, Newfane, Vermont: U.S. Geological Survey Open-File Report 97-218, iv, 48 p., https://doi.org/10.3133/ofr97218.","productDescription":"iv, 48 p.","numberOfPages":"53","costCenters":[],"links":[{"id":169645,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97218.GIF"},{"id":279778,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0218/report.pdf"}],"scale":"25000","country":"United States","state":"Vermont","city":"Newfane","otherGeospatial":"Smith Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.75,42.875 ], [ -72.75,43.0 ], [ -72.5,43.0 ], [ -72.5,42.875 ], [ -72.75,42.875 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b19e4b07f02db6a7eb9","contributors":{"authors":[{"text":"Ivanoff, Michael A.","contributorId":27105,"corporation":false,"usgs":true,"family":"Ivanoff","given":"Michael","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":240458,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Medalie, Laura 0000-0002-2440-2149 lmedalie@usgs.gov","orcid":"https://orcid.org/0000-0002-2440-2149","contributorId":3657,"corporation":false,"usgs":true,"family":"Medalie","given":"Laura","email":"lmedalie@usgs.gov","affiliations":[{"id":466,"text":"New England Water Science Center","active":true,"usgs":true}],"preferred":true,"id":240457,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":50011,"text":"ofr97775 - 1997 - Level II scour analysis for Bridge 39 (PEACTH00620039) on Town Highway 62, crossing South Peacham Brook, Peacham, Vermont","interactions":[],"lastModifiedDate":"2013-12-17T14:50:57","indexId":"ofr97775","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-775","title":"Level II scour analysis for Bridge 39 (PEACTH00620039) on Town Highway 62, crossing South Peacham Brook, Peacham, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nPEACTH00620039 on Town Highway 62 crossing South Peacham Brook, Peacham, \nVermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including \na quantitative analysis of stream stability and scour (U.S. Department of Transportation, \n1993). Results of a Level I scour investigation also are included in Appendix E of this \nreport. A Level I investigation provides a qualitative geomorphic characterization of the \nstudy site. Information on the bridge, gleaned from Vermont Agency of Transportation \n(VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is \nfound in Appendix D.\nThe site is in the New England Upland section of the New England physiographic province \nin northeastern Vermont. The 9.1-mi2\n drainage area is in a predominantly rural and forested \nbasin. In the vicinity of the study site, the surface cover is forest on the left bank upstream \nand downstream of the bridge. The surface cover on the right bank upstream and \ndownstream is shrubs and brush.\nIn the study area, South Peacham Brook has an incised, straight channel with a slope of \napproximately 0.02 ft/ft, an average channel top width of 43 ft and an average bank height \nof 8 ft. The channel bed material ranges from sand to boulder with a median grain size (D50) \nof 51.4 mm (0.168 ft). The geomorphic assessment at the time of the Level I and Level II \nsite visit on August 23, 1995, indicated that the reach was stable.\nThe Town Highway 62 crossing of South Peacham Brook is a 23-ft-long, one-lane bridge \nconsisting of one 22-foot steel-beam span (Vermont Agency of Transportation, written \ncommunication, March 27, 1995). The opening length of the structure parallel to the bridge \nface is 20.1 ft. The bridge is supported by vertical, concrete abutments with wingwalls. The \nchannel is skewed approximately 15 degrees to the opening while the computed openingskew-to-roadway is 10 degrees. \nThe footing on the right abutment and the footing on the upstream left wingwall were \nexposed during the Level I assessment. The scour countermeasures at the site included type-\n2 stone fill (less than 36 inches diameter) along the upstream and downstream right \nwingwalls and at the upstream end of the upstream left wingwall and at the downstream end \nof the downstream left wingwall. Type-3 stone fill (less than 48 inches diameter) was along \nthe upstream left and right banks and the downstream right bank. On the downstream left \nbank, the scour countermeasure was a stone wall. Additional details describing conditions \nat the site are included in the Level II Summary and Appendices D and E.\nScour depths and recommended rock rip-rap sizes were computed using the general \nguidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995) \nfor the 100- and 500-year discharges. In addition, the incipient roadway-overtopping \ndischarge is determined and analyzed as another potential worst-case scour scenario. Total \nscour at a highway crossing is comprised of three components: 1) long-term streambed \ndegradation; 2) contraction scour (due to accelerated flow caused by a reduction in flow \narea at a bridge) and; 3) local scour (caused by accelerated flow around piers and \nabutments). Total scour is the sum of the three components. Equations are available to \ncompute depths for contraction and local scour and a summary of the results of these \ncomputations follows.\nContraction scour for all modelled flows ranged from 1.0 to 1.6 ft. The worst-case \ncontraction scour occurred at the 100-year discharge. Abutment scour ranged from 5.9 to \n7.4 ft. The worst-case abutment scour occurred at the incipient roadway-overtopping \ndischarge, which is less than the 100-year discharge. Additional information on scour \ndepths and depths to armoring are included in the section titled “Scour Results”. Scouredstreambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. \nA cross-section of the scour computed at the bridge is presented in figure 8. Scour depths \nwere calculated assuming an infinite depth of erosive material and a homogeneous particlesize distribution. However, there is a bedrock outcrop across the channel just upstream of \nthe bridge.\nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr97775","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Burns, R.L., and Degnan, J.R., 1997, Level II scour analysis for Bridge 39 (PEACTH00620039) on Town Highway 62, crossing South Peacham Brook, Peacham, Vermont: U.S. Geological Survey Open-File Report 97-775, iv, 51 p., https://doi.org/10.3133/ofr97775.","productDescription":"iv, 51 p.","numberOfPages":"56","costCenters":[],"links":[{"id":176809,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97775.PNG"},{"id":279668,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0775/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Peacham","otherGeospatial":"Peacham Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.75,43.5 ], [ -72.75,43.625 ], [ -72.625,43.625 ], [ -72.625,43.5 ], [ -72.75,43.5 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a625b","contributors":{"authors":[{"text":"Burns, Ronda L.","contributorId":71602,"corporation":false,"usgs":true,"family":"Burns","given":"Ronda","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":240631,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Degnan, James R. 0000-0002-5665-9010 jrdegnan@usgs.gov","orcid":"https://orcid.org/0000-0002-5665-9010","contributorId":498,"corporation":false,"usgs":true,"family":"Degnan","given":"James","email":"jrdegnan@usgs.gov","middleInitial":"R.","affiliations":[{"id":405,"text":"NH/VT office of New England Water Science Center","active":true,"usgs":true},{"id":466,"text":"New England Water Science Center","active":true,"usgs":true}],"preferred":true,"id":240630,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":50012,"text":"ofr97776 - 1997 - Level II scour analysis for Bridge 34 (CONCTH00110034) on Town Highway 11, crossing Miles Stream, Concord, Vermont","interactions":[],"lastModifiedDate":"2013-12-17T14:45:22","indexId":"ofr97776","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-776","title":"Level II scour analysis for Bridge 34 (CONCTH00110034) on Town Highway 11, crossing Miles Stream, Concord, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nCONCTH00110034 on Town Highway 11 crossing Miles Stream, Concord, Vermont \n(figures 1–8). A Level II study is a basic engineering analysis of the site, including a \nquantitative analysis of stream stability and scour (U.S. Department of Transportation, \n1993). Results of a Level I scour investigation also are included in Appendix E of this \nreport. A Level I investigation provides a qualitative geomorphic characterization of the \nstudy site. Information on the bridge, gleaned from Vermont Agency of Transportation \n(VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is \nfound in Appendix D.\nThe site is in the New England Upland section of the New England physiographic province \nin northeastern Vermont. The 24.9-mi2\n drainage area is in a predominantly rural and \nforested basin. In the vicinity of the study site, the surface cover is shrub and brush on the \nleft bank upstream and downstream of the bridge. The surface cover on the right bank \nupstream is pasture while downstream it is forest.\nIn the study area, Miles Stream has an incised, sinuous channel with a slope of \napproximately 0.005 ft/ft, an average channel top width of 48 ft and an average bank height \nof 4 ft. The channel bed material ranges from gravel to boulder with a median grain size \n(D50) of 102 mm (0.335 ft). The geomorphic assessment at the time of the Level I and Level \nII site visit on August 15, 1995, indicated that the reach was stable.\nThe Town Highway 11 crossing of Miles Stream is a 38-ft-long, two-lane bridge consisting \nof one 36-foot concrete slab span (Vermont Agency of Transportation, written \ncommunication, March 16, 1995). The opening length of the structure parallel to the bridge \nface is 33.9 ft. The bridge is supported by vertical, concrete abutments with wingwalls. The \nchannel is skewed approximately 20 degrees to the opening. The calculated opening-skewto-roadway is 25 degrees while the VTAOT determined opening-skew-to-roadway is 22 \ndegrees.\nThe scour countermeasures at the site included type-2 stone fill (less than 36 inches \ndiameter) along the entire base length of all four wingwalls, scattered in front of the left and \nright abutments, and along the downstream left and right banks. Also, there is type-3 stone \nfill (less than 48 inches diameter) along the upstream left and right banks. Additional \ndetails describing conditions at the site are included in the Level II Summary and \nAppendices D and E.\nScour depths and recommended rock rip-rap sizes were computed using the general \nguidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995) \nfor the 100- and 500-year discharges. In addition, the incipient roadway-overtopping \ndischarge is determined and analyzed as another potential worst-case scour scenario. Total \nscour at a highway crossing is comprised of three components: 1) long-term streambed \ndegradation; 2) contraction scour (due to accelerated flow caused by a reduction in flow \narea at a bridge) and; 3) local scour (caused by accelerated flow around piers and \nabutments). Total scour is the sum of the three components. Equations are available to \ncompute depths for contraction and local scour and a summary of the results of these \ncomputations follows.\nContraction scour for all modelled flows ranged from 0.0 to 1.3 ft. The worst-case \ncontraction scour occurred at the incipient roadway-overtopping discharge, which was less \nthan the 100-year discharge. The right abutment scour ranged from 7.4 to 9.6 ft while the \nleft abutment scour ranged from 12.8 to 14.4 ft. The worst-case abutment scour for the left \nand right abutments occurred at the 500-year discharge. Additional information on scour \ndepths and depths to armoring are included in the section titled “Scour Results”. Scouredstreambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. \nA cross-section of the scour computed at the bridge is presented in figure 8. Scour depths \nwere calculated assuming an infinite depth of erosive material and a homogeneous particlesize distribution. However, there is exposed bedrock in the channel upstream and \ndownstream of the bridge.\nUsually, computed scour depths are evaluated in combination with other information \nincluding (but not limited to) historical performance during flood events, the geomorphic \nstability assessment, existing scour protection measures, and the results of the hydraulic \nanalyses. Therefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr97776","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Burns, R.L., and Hammond, R.E., 1997, Level II scour analysis for Bridge 34 (CONCTH00110034) on Town Highway 11, crossing Miles Stream, Concord, Vermont: U.S. Geological Survey Open-File Report 97-776, iv, 51 p., https://doi.org/10.3133/ofr97776.","productDescription":"iv, 51 p.","numberOfPages":"56","costCenters":[],"links":[{"id":176810,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97776.PNG"},{"id":279667,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0776/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Concord","otherGeospatial":"Miles Stream","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.75,43.5 ], [ -72.75,43.625 ], [ -72.625,43.625 ], [ -72.625,43.5 ], [ -72.75,43.5 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b18e4b07f02db6a7363","contributors":{"authors":[{"text":"Burns, Ronda L.","contributorId":71602,"corporation":false,"usgs":true,"family":"Burns","given":"Ronda","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":240633,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Hammond, Robert E.","contributorId":61862,"corporation":false,"usgs":true,"family":"Hammond","given":"Robert","email":"","middleInitial":"E.","affiliations":[],"preferred":false,"id":240632,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49906,"text":"ofr97217 - 1997 - Level II scour analysis for Bridge 23 (CRAFTH00390023) on Town Highway 39, crossing the Black River, Craftsbury, Vermont","interactions":[],"lastModifiedDate":"2013-12-20T10:01:42","indexId":"ofr97217","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-217","title":"Level II scour analysis for Bridge 23 (CRAFTH00390023) on Town Highway 39, crossing the Black River, Craftsbury, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nCRAFTH00390023 on town highway 39 crossing the Black River, Craftsbury, Vermont \n(figures 1–8). A Level II study is a basic engineering analysis of the site, including a \nquantitative analysis of stream stability and scour (U.S. Department of Transportation, \n1993). A Level I assessment is included in Appendix E of this report. A Level I assessment \nprovides a qualitative geomorphic characterization of the study site. Information on the \nbridge, gleaned from VTAOT files, was compiled prior to conducting Level I and Level II \nanalyses and is provided in Appendix D.\nThe site is in the New England Upland physiographic province of North-central Vermont in \nthe town of Craftsbury. The 30.9-mi2\n drainage area is in a predominantly rural and forested \nbasin with some pasture grassland on the valley bottom. In the vicinity of the study site, the \nbanks have very little woody vegetation coverage except for the downstream left bank, \nwhich has some trees and brush coverage.\nIn the study area, the Black River has an meandering channel with a slope of approximately \n0.0004 ft/ft, an average channel top width of 62 ft and an average channel depth of 3 ft. The \npredominant channel bed materials are sand and gravel with a median grain size (D50) of \n0.73 mm (0.0024 ft). The geomorphic assessment at the time of the Level I and Level II site \nvisit on June 6, 1995, indicated that the reach was laterally unstable.\nThe town highway 39 crossing of the Black River is a 65-ft-long, two-lane bridge consisting \nof three spans with a maximum span of 38-feet (Vermont Agency of Transportation, written \ncommunication, August 24, 1994). The bridge is supported by vertical, concrete abutments \nand two stone piers with concrete caps. The channel is skewed approximately 10 degrees to \nthe opening while the opening-skew-to-roadway is 10 degrees in the opposite direction.\nThe scour protection measures at the site were type-1 stone fill (less than 12 inches \ndiameter) on the upstream left and right roadway embankments and between the right pier \nand right abutment wall. Type-2 (less than 36 inches diameter) stone fill was evident on the \nupstream left bank, downstream right bank, between the left pier and left abutment wall, \nand streamward of the right pier. Additional details describing conditions at the site are \nincluded in the Level II Summary and Appendices D and E.\nScour depths and rock rip-rap sizes were computed using the general guidelines described \nin Hydraulic Engineering Circular 18 (Richardson and others, 1995).\nTotal scour at a highway crossing is comprised of three components: 1) long-term \naggradation or degradation; 2) contraction scour (due to reduction in flow area caused by a \nbridge) and; 3) local scour (caused by accelerated flow around piers and abutments). Total \nscour is the sum of the three components. Equations are available to compute scour depths \nfor contraction and local scour and a summary of the results follows.\nContraction scour for all modelled flows ranged from 20.1 to 25.2 and the worst-case \ncontraction scour occurred at the 500-year discharge. Although this bridge has two piers, \nthe flow through the spans between each abutment and pier is assumed to be negligible. \nHence, abutment scour was computed assuming the forces contributing to scour actually \noccur on the main-span sides of each pier in this case. Abutment scour ranged from 8.8 to \n10.6 and the worst-case abutment scour occurred at the 500-year discharge. Scour depths \nand depths to armoring are summarized on p. 14 in the section titled “Scour Results”. Scour \nelevations, based on the calculated depths are presented in tables 1 and 2. A graph of the \nscour elevations is presented in figure 8. Scour depths were calculated assuming an infinite \ndepth of erosive material and a homogeneous particle-size distribution. \nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr97217","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Boehmler, E.M., 1997, Level II scour analysis for Bridge 23 (CRAFTH00390023) on Town Highway 39, crossing the Black River, Craftsbury, Vermont: U.S. Geological Survey Open-File Report 97-217, iv, 51 p., https://doi.org/10.3133/ofr97217.","productDescription":"iv, 51 p.","numberOfPages":"56","costCenters":[],"links":[{"id":169644,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97217.PNG"},{"id":279779,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0217/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Craftsbury","otherGeospatial":"Black River","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.75,43.5 ], [ -72.75,43.625 ], [ -72.625,43.625 ], [ -72.625,43.5 ], [ -72.75,43.5 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b1ae4b07f02db6a80f2","contributors":{"authors":[{"text":"Boehmler, Erick M.","contributorId":96303,"corporation":false,"usgs":true,"family":"Boehmler","given":"Erick","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":240456,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":49904,"text":"ofr97215 - 1997 - Level II scour analysis for Bridge 8 (STAMVT01000008) on State Highway 100, crossing the North Branch of the Hoosic River, Stamford, Vermont","interactions":[],"lastModifiedDate":"2013-12-20T10:17:32","indexId":"ofr97215","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-215","title":"Level II scour analysis for Bridge 8 (STAMVT01000008) on State Highway 100, crossing the North Branch of the Hoosic River, Stamford, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure STAMVT01000008 on Vermont Highway 100 crossing the North Branch of the Hoosic River, Stamford, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including a quantitative analysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of a Level I scour investigation also are included in Appendix E of this report. A Level I investigation provides a qualitative geomorphic characterization of the study site. Information on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is found in Appendix D.\nThe site is in the Green Mountain section of the New England physiographic province in southern Vermont. The 6.8-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the upstream right bank surface cover is short grass and the upstream left bank is a sand/gravel lot while the immediate banks are covered by shrubs and trees. Downstream of the bridge banks are forested.\nIn the study area, the North Branch of the Hoosic River has an incised, sinuous channel with a slope of approximately 0.02 ft/ft, an average channel top width of 37 ft and an average bank height of 3 ft. The channel bed material is predominantly cobble with a median grain size (D50) of 88.0 mm (0.289 ft). The geomorphic assessment at the time of the Level I and Level II site visit on August 1, 1996, indicated that the reach was laterally unstable.\nThe Vermont Highway 100 crossing of the North Branch of the Hoosic River is a 39-ft-long, two-lane bridge consisting of one 37-foot steel-beam span (Vermont Agency of Transportation, written communication, November 1, 1995). The bridge is supported by vertical, concrete abutments. The channel is skewed approximately 20 degrees to the opening while the opening-skew-to-roadway is 15 degrees.\nA scour hole 2.5 ft deeper than the mean thalweg depth was observed along the upstream end of the right abutment during the Level I assessment. The only scour protection measure at the site was type-3 stone fill (less than 48 inches diameter) at the downstream ends of the left and right abutments extending downstream along the left bank for 13 feet and along the right bank for 16 feet. The plans show stone fill placed at the upstream ends of the abutments. The protection at the upstream end of the right abutment has failed due to stream migration towards the right bank. The protection at the upstream end of the left abutment was not detected due to the sand/gravel pile, for District 1 maintenance, migrating into the channel (Figure 3). Additional details describing conditions at the site are included in the Level II Summary and Appendices D and E.\nScour depths and rock rip-rap sizes were computed using the general guidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995). Total scour at a highway crossing is comprised of three components: 1) long-term streambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is the sum of the three components. Equations are available to compute depths for contraction and local scour and a summary of the results of these computations follows.\nContraction scour for all modelled flows ranged from 0.6 to 3.0 ft. The worst-case contraction scour occurred at the 500-year discharge. Left abutment scour ranged from 14.4 to 17.8 ft. Right abutment scour ranged from 8.1 to 11.1 ft. The worst-case abutment scour occurred at the 500-year discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution.\nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, computed scour depths are evaluated in combination with other information including (but not limited to) historical performance during flood events, the geomorphic stability assessment, existing scour protection measures, and the results of the hydraulic analyses. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein.","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr97215","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Ivanoff, M.A., 1997, Level II scour analysis for Bridge 8 (STAMVT01000008) on State Highway 100, crossing the North Branch of the Hoosic River, Stamford, Vermont: U.S. Geological Survey Open-File Report 97-215, iv, 50 p., https://doi.org/10.3133/ofr97215.","productDescription":"iv, 50 p.","numberOfPages":"55","costCenters":[],"links":[{"id":169642,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97215.PNG"},{"id":279781,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0215/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Stamford","otherGeospatial":"Hoosic River","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -73.125,42.75 ], [ -73.125,42.875 ], [ -73.0,42.875 ], [ -73.0,42.75 ], [ -73.125,42.75 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b16e4b07f02db6a562f","contributors":{"authors":[{"text":"Ivanoff, Michael A.","contributorId":27105,"corporation":false,"usgs":true,"family":"Ivanoff","given":"Michael","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":240454,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":50013,"text":"ofr97779 - 1997 - Level II scour analysis for Bridge 27 (STJOTH00080027) on Town Highway 8, crossing the Sleepers River, St. Johnsbury, Vermont","interactions":[],"lastModifiedDate":"2013-12-17T14:40:15","indexId":"ofr97779","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-779","title":"Level II scour analysis for Bridge 27 (STJOTH00080027) on Town Highway 8, crossing the Sleepers River, St. Johnsbury, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nSTJOTH00080027 on Town Highway 8 crossing the Sleepers River, \nSt. Johnsbury, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the \nsite, including a quantitative analysis of stream stability and scour (U.S. Department of \nTransportation, 1993). Results of a Level I scour investigation also are included in \nAppendix E of this report. A Level I investigation provides a qualitative geomorphic \ncharacterization of the study site. Information on the bridge, gleaned from Vermont Agency \nof Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II \nanalyses and is found in Appendix D.\nThe site is in the New England Upland section of the New England physiographic province \nin northeastern Vermont. The 40.4-mi2\n drainage area is in a predominantly rural and \nforested basin. In the vicinity of the study site, the surface cover is forest on the upstream \nright bank with some pasture on the upstream left bank. The downstream right overbank \ncover is comprised of cut grass, trees and shrubs while the immediate banks have dense \nwoody vegetation. The downstream left bank is forested with some pasture.\nIn the study area, the Sleepers River has an incised, sinuous channel with a slope of \napproximately 0.007 ft/ft, an average channel top width of 72 ft and an average bank height \nof 5 ft. The channel bed material ranges from gravel to cobble with a median grain size \n(D50) of 48.5 mm (0.159 ft). The geomorphic assessment at the time of the Level I and \nLevel II site visit on August 10, 1995, indicated that the reach was stable.\nThe Town Highway 8 crossing of the Sleepers River is a 74-ft-long, two-lane bridge \nconsisting of one 71-foot steel-beam span (Vermont Agency of Transportation, written \ncommunication, March 28, 1995). The opening length of the structure parallel to the bridge \nface is 68 ft. The bridge is supported by vertical, concrete abutments with wingwalls. The \nchannel is skewed approximately 50 degrees to the opening while the computed openingskew-to-roadway is 45 degrees. The VTAOT database states the opening-skew-to-roadway \nas 30 degrees.\nA scour hole 2.5 ft deeper than the mean thalweg depth was observed along the right \nabutment during the Level I assessment. There is also a three to four foot deep scour hole in \nthe channel adjacent to the upstream right wingwall. The scour protection at the site \nincluded type-3 stone fill (less than 48 inches diameter) at the upstream end of the upstream \nleft wingwall, at the downstream end of the downstream right wingwall, and along the \ndownstream left bank. There was also type-2 stone fill (less than 36 inches diameter) at the \ndownstream end of the downstream left wingwall, along the upstream left bank, and along \nthe downstream right bank. Additional details describing conditions at the site are included \nin the Level II Summary and Appendices D and E.\nScour depths and recommended rock rip-rap sizes were computed using the general \nguidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995) \nfor the 100- and 500-year discharges. In addition, the incipient roadway-overtopping \ndischarge is determined and analyzed as another potential worst-case scour scenario. Total \nscour at a highway crossing is comprised of three components: 1) long-term streambed \ndegradation; 2) contraction scour (due to accelerated flow caused by a reduction in flow \narea at a bridge) and; 3) local scour (caused by accelerated flow around piers and \nabutments). Total scour is the sum of the three components. Equations are available to \ncompute depths for contraction and local scour and a summary of the results of these \ncomputations follows.\nContraction scour computed for all modelled flows was zero ft. Abutment scour ranged \nfrom 6.2 to 9.7 ft. The worst-case abutment scour occurred at the 100-year discharge at the \nright abutment and at the 500-year discharge at the left abutment. Additional information on \nscour depths and depths to armoring are included in the section titled “Scour Results”. \nScoured-streambed elevations, based on the calculated scour depths, are presented in tables \n1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour \ndepths were calculated assuming an infinite depth of erosive material and a homogeneous \nparticle-size distribution. \nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr97779","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Administration","usgsCitation":"Ivanoff, M.A., 1997, Level II scour analysis for Bridge 27 (STJOTH00080027) on Town Highway 8, crossing the Sleepers River, St. Johnsbury, Vermont: U.S. Geological Survey Open-File Report 97-779, iv, 51 p., https://doi.org/10.3133/ofr97779.","productDescription":"iv, 51 p.","numberOfPages":"56","costCenters":[],"links":[{"id":176811,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97779.PNG"},{"id":279666,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0779/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"St. Johnsbury","otherGeospatial":"Sleepers River","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.25,44.375 ], [ -72.25,44.5 ], [ -72.0,44.5 ], [ -72.0,44.375 ], [ -72.25,44.375 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b1ae4b07f02db6a7fe8","contributors":{"authors":[{"text":"Ivanoff, Michael A.","contributorId":27105,"corporation":false,"usgs":true,"family":"Ivanoff","given":"Michael","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":240634,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":50014,"text":"ofr97780 - 1997 - Level II scour analysis for Bridge 36 (STOWTH00430036) on Town Highway 43, crossing Miller Brook, Stowe, Vermont","interactions":[],"lastModifiedDate":"2016-08-25T13:11:16","indexId":"ofr97780","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-780","title":"Level II scour analysis for Bridge 36 (STOWTH00430036) on Town Highway 43, crossing Miller Brook, Stowe, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure STOWTH00430036 on Town Highway 43 crossing the Miller Brook, Stowe, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including a quantitative analysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of a Level I scour investigation also are included in Appendix E of this report. A Level I investigation provides a qualitative geomorphic characterization of the study site. Information on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is found in Appendix D.
The site is in the Green Mountain section of the New England physiographic province in north central Vermont. The 5.5-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is predominantly forested.
In the study area, the Miller Brook has an incised, sinuous channel with a slope of approximately 0.03 ft/ft, an average channel top width of 43 ft and an average bank height of 7 ft. The channel bed material ranges from gravel to boulder with a median grain size (D50) of 70.4 mm (0.231 ft). The geomorphic assessment at the time of the Level I and Level II site visit on July 15, 1996, indicated that the reach was stable.
The Town Highway 43 crossing of the Miller Brook is a 24-ft-long, two-lane bridge consisting of one 21-foot steel-beam span (Vermont Agency of Transportation, written communication, October 13, 1995). The opening length of the structure parallel to the bridge face is 21.5 ft. The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 10 degrees to the opening and the computed opening-skew-to-roadway is also 10 degrees.
The footing on the left abutment was exposed 2.5 ft and the footing on the right abutment was exposed 3.0 ft during the Level I assessment. Scour protection measures at the site were type-4 stone fill (less than 60 inches diameter) on the left and right bank upstream, type-3 stone fill (less than 48 inches diameter) along the entire base length of the upstream right wingwall, right abutment, and type-2 stone fill (less than 36 inches diameter) along the entire base length of the downstream right wingwall, and left and right banks downstream. Additional details describing conditions at the site are included in the Level II Summary and Appendices D and E.
Scour depths and recommended rock rip-rap sizes were computed using the general guidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995) for the 100- and 500-year discharges. In addition, the incipient roadway-overtopping discharge is determined and analyzed as another potential worst-case scour scenario. Total scour at a highway crossing is comprised of three components: 1) long-term streambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is the sum of the three components. Equations are available to compute depths for contraction and local scour and a summary of the results of these computations follows.
Contraction scour for all modelled flows ranged from 0.0 to 0.9 ft. The worst-case contraction scour occurred at the 500-year discharge. Abutment scour ranged from 3.1 to 6.5 ft. The worst-case abutment scour occurred at the 100-year discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution.
It is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, computed scour depths are evaluated in combination with other information including (but not limited to) historical performance during flood events, the geomorphic stability assessment, existing scour protection measures, and the results of the hydraulic analyses. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr97780","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Striker, L.K., and Wild, E.C., 1997, Level II scour analysis for Bridge 36 (STOWTH00430036) on Town Highway 43, crossing Miller Brook, Stowe, Vermont: U.S. Geological Survey Open-File Report 97-780, iv, 51 p., https://doi.org/10.3133/ofr97780.","productDescription":"iv, 51 p.","numberOfPages":"56","costCenters":[],"links":[{"id":176812,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97780.PNG"},{"id":279665,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0780/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Stowe","otherGeospatial":"Miller Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.875,44.375 ], [ -72.875,44.5 ], [ -72.75,44.5 ], [ -72.75,44.375 ], [ -72.875,44.375 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a638b","contributors":{"authors":[{"text":"Striker, Lora K.","contributorId":41481,"corporation":false,"usgs":true,"family":"Striker","given":"Lora","email":"","middleInitial":"K.","affiliations":[],"preferred":false,"id":240636,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Wild, Emily C. 0000-0001-6157-7629 ecwild@usgs.gov","orcid":"https://orcid.org/0000-0001-6157-7629","contributorId":1810,"corporation":false,"usgs":true,"family":"Wild","given":"Emily","email":"ecwild@usgs.gov","middleInitial":"C.","affiliations":[{"id":5081,"text":"Libraries","active":false,"usgs":true}],"preferred":false,"id":240635,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":50015,"text":"ofr97781 - 1997 - Level II scour analysis for Bridge 37 (CABOTH00410037) on Town Highway 41, crossing the Winooski River, Cabot, Vermont","interactions":[],"lastModifiedDate":"2013-12-17T14:23:29","indexId":"ofr97781","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-781","title":"Level II scour analysis for Bridge 37 (CABOTH00410037) on Town Highway 41, crossing the Winooski River, Cabot, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nCABOTH00410037 on Town Highway 41 crossing the Winooski River (also referred to as \nCoit’s Pond Brook), Cabot, Vermont (figures 1–8). A Level II study is a basic engineering \nanalysis of the site, including a quantitative analysis of stream stability and scour (U.S. \nDepartment of Transportation, 1993). Results of a Level I scour investigation also are \nincluded in Appendix E of this report. A Level I investigation provides a qualitative \ngeomorphic characterization of the study site. Information on the bridge, gleaned from \nVermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level \nI and Level II analyses and is found in Appendix D.\nThe site is in the New England Upland section of the New England physiographic province \nin northeastern Vermont. The 21.4-mi2\n drainage area is in a predominantly rural and \nforested basin. In the vicinity of the study site, the surface cover is primarily shrub and \nbrushland while the immediate banks have dense woody vegetation.\nIn the study area, the Winooski River has an incised, straight channel with a slope of \napproximately 0.01 ft/ft, an average channel top width of 53 ft and an average bank height \nof 4 ft. The channel bed material is primarily cobbles and boulder with a median grain size \n(D50) of 64.5 mm (0.212 ft). The geomorphic assessment at the time of the Level I and \nLevel II site visit on July 16, 1996, indicated that the reach was stable.\nThe Town Highway 41 crossing of the Winooski River is a 29-ft-long, one-lane bridge \nconsisting of one 26-foot span (Vermont Agency of Transportation, written \ncommunication, October 13, 1995) with four steel I-beams and a wooden deck . The \nopening length of the structure parallel to the bridge face is 26 ft.The bridge is supported by \n“laid up” granite block abutments with concrete footings. The channel is skewed \napproximately 35 degrees to the opening while the computed opening-skew-to-roadway is \n15 degrees. The VTAOT computed opening-skew-to-roadway is zero degrees.\nThe only scour protection measure observed at the site during the Level I assessment was \ntype-2 stone fill (less than 36 inches diameter) along the entire base length of the left \nabutment and upstream right wingwall, along the upstream left bank and along the \ndownstream left and right banks. Additional details describing conditions at the site are \nincluded in the Level II Summary and Appendices \nD and E.\nScour depths and recommended rock rip-rap sizes were computed using the general \nguidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995) \nfor the 100- and 500-year discharges. In addition, the incipient roadway-overtopping and \nmaximum free-surface flow discharges were determined and analyzed as two other \npotential worst-case scour scenarios. Total scour at a highway crossing is comprised of \nthree components: 1) long-term streambed degradation; 2) contraction scour (due to \naccelerated flow caused by a reduction in flow area at a bridge) and; 3) local scour (caused \nby accelerated flow around piers and abutments). Total scour is the sum of the three \ncomponents. Equations are available to compute depths for contraction and local scour and \na summary of the results of these computations follows.\nContraction scour for all modelled flows ranged from 0.0 to 2.7 ft. The worst-case \ncontraction scour occurred at the maximum free-surface flow (with road overflow) \ndischarge, which was less than the 100-year discharge. Abutment scour ranged from 9.8 to \n10.7 ft along the left abutment and from 16.2 to 19.9 ft along the right abutment. The worstcase abutment scour occurred at the 500-year discharge. Additional information on scour \ndepths and depths to armoring are included in the section titled “Scour Results”. Scouredstreambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. \nA cross-section of the scour computed at the bridge is presented in figure 8. Scour depths \nwere calculated assuming an infinite depth of erosive material and a homogeneous particlesize distribution. \nIt is generally accepted that the Froehlich and Hire equations (abutment scour) gives \n“excessively conservative estimates of scour depths” (Richardson and others, 1995, p. 47). \nUsually, computed scour depths are evaluated in combination with other information \nincluding (but not limited to) historical performance during flood events, the geomorphic \nstability assessment, existing scour protection measures, and the results of the hydraulic \nanalyses. Therefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr97781","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Flynn, R.H., and Medalie, L., 1997, Level II scour analysis for Bridge 37 (CABOTH00410037) on Town Highway 41, crossing the Winooski River, Cabot, Vermont: U.S. Geological Survey Open-File Report 97-781, iv, 52 p., https://doi.org/10.3133/ofr97781.","productDescription":"iv, 52 p.","numberOfPages":"57","costCenters":[],"links":[{"id":162660,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97781.PNG"},{"id":279664,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0781/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Cabot","otherGeospatial":"Winooski River","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.375,44.375 ], [ -72.375,44.5 ], [ -72.25,44.5 ], [ -72.25,44.375 ], [ -72.375,44.375 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a6376","contributors":{"authors":[{"text":"Flynn, Robert H. rflynn@usgs.gov","contributorId":2137,"corporation":false,"usgs":true,"family":"Flynn","given":"Robert","email":"rflynn@usgs.gov","middleInitial":"H.","affiliations":[{"id":405,"text":"NH/VT office of New England Water Science Center","active":true,"usgs":true}],"preferred":true,"id":240637,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Medalie, Laura 0000-0002-2440-2149 lmedalie@usgs.gov","orcid":"https://orcid.org/0000-0002-2440-2149","contributorId":3657,"corporation":false,"usgs":true,"family":"Medalie","given":"Laura","email":"lmedalie@usgs.gov","affiliations":[{"id":466,"text":"New England Water Science Center","active":true,"usgs":true}],"preferred":true,"id":240638,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":50016,"text":"ofr97782 - 1997 - Level II scour analysis for Bridge 17 (SHEFTH00380017) on Town Highway 38, crossing Miller Run, Sheffield, Vermont","interactions":[],"lastModifiedDate":"2013-12-17T14:15:08","indexId":"ofr97782","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-782","title":"Level II scour analysis for Bridge 17 (SHEFTH00380017) on Town Highway 38, crossing Miller Run, Sheffield, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nSHEFTH00380017 on Town Highway 38 crossing Miller Run, Sheffield, Vermont (figures \n1–8). A Level II study is a basic engineering analysis of the site, including a quantitative \nanalysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of \na Level I scour investigation also are included in Appendix E of this report. A Level I \ninvestigation provides a qualitative geomorphic characterization of the study site. \nInformation on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) \nfiles, was compiled prior to conducting Level I and Level II analyses and is found in \nAppendix D.\nThe site is in the White Mountain section of the New England physiographic province in \nnortheastern Vermont. The 24.2-mi2\n drainage area is in a predominantly rural and forested \nbasin. In the vicinity of the study site, the surface cover is pasture along the right bank while \nthe immediate banks are covered by trees, shrubs, and brush. The surface cover along the \nleft bank is grass and Route 122 with shrubs and brush along the immediate banks.\nIn the study area, Miller Run has a sinuous channel with a slope of approximately 0.01 ft/ft, \nan average channel top width of 52 ft and an average bank height of 3 ft. The channel bed \nmaterial ranges from sand to bedrock with a median grain size (D50) of 80.5 mm (0.264 ft). \nThe geomorphic assessment at the time of the Level I and Level II site visit on August 1, \n1995, indicated that the reach was stable.\nThe Town Highway 38 crossing of Miller Run is a 52-ft-long, one-lane bridge consisting of \none 48-foot steel I-beam span with a wooden deck (Vermont Agency of Transportation, \nwritten communication, March 28, 1995). The opening length of the structure parallel to the \nbridge face is 42.4 ft. The bridge is supported by vertical, concrete abutments with \nwingwalls on the upstream end. The channel is skewed approximately 30 degrees to the \nopening while the computed opening-skew-to-roadway is 5 degrees.\nA scour hole 3.0 ft deeper than the mean thalweg depth was observed under the bridge \nduring the Level I assessment. The only scour protection measure at the site was type-4 \nstone fill (less than 60 inches diameter) at the upstream end of the upstream left wingwall. \nAdditional details describing conditions at the site are included in the Level II Summary \nand Appendices D and E.\nScour depths and recommended rock rip-rap sizes were computed using the general \nguidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995) \nfor the 100- and 500-year discharges. In addition, the incipient roadway-overtopping \ndischarge is determined and analyzed as another potential worst-case scour scenario. Total \nscour at a highway crossing is comprised of three components: 1) long-term streambed \ndegradation; 2) contraction scour (due to accelerated flow caused by a reduction in flow \narea at a bridge) and; 3) local scour (caused by accelerated flow around piers and \nabutments). Total scour is the sum of the three components. Equations are available to \ncompute depths for contraction and local scour and a summary of the results of these \ncomputations follows.\nContraction scour for modelled flows ranged from 0.0 to 2.4 ft. Abutment scour ranged \nfrom 6.1 to 7.9 ft at the left abutment and 11.4 to 17.4 ft at the right abutment. The worstcase contraction and abutment scour occurred at the 500-year discharge. Additional \ninformation on scour depths and depths to armoring are included in the section titled “Scour \nResults”. Scoured-streambed elevations, based on the calculated scour depths, are presented \nin tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure \n8. Scour depths were calculated assuming an infinite depth of erosive material and a \nhomogeneous particle-size distribution. \nUsually, computed scour depths are evaluated in combination with other information \nincluding (but not limited to) historical performance during flood events, the geomorphic \nstability assessment, existing scour protection measures, and the results of the hydraulic \nanalyses. Therefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr97782","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Striker, L.K., and Degnan, J.R., 1997, Level II scour analysis for Bridge 17 (SHEFTH00380017) on Town Highway 38, crossing Miller Run, Sheffield, Vermont: U.S. Geological Survey Open-File Report 97-782, iv, 51 p., https://doi.org/10.3133/ofr97782.","productDescription":"iv, 51 p.","numberOfPages":"56","costCenters":[],"links":[{"id":162661,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97782.PNG"},{"id":279663,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0782/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Sheffield","otherGeospatial":"Miller Run","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.125,44.5 ], [ -72.125,44.625 ], [ -72.0,44.625 ], [ -72.0,44.5 ], [ -72.125,44.5 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b1ae4b07f02db6a823f","contributors":{"authors":[{"text":"Striker, Lora K.","contributorId":41481,"corporation":false,"usgs":true,"family":"Striker","given":"Lora","email":"","middleInitial":"K.","affiliations":[],"preferred":false,"id":240640,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Degnan, James R. 0000-0002-5665-9010 jrdegnan@usgs.gov","orcid":"https://orcid.org/0000-0002-5665-9010","contributorId":498,"corporation":false,"usgs":true,"family":"Degnan","given":"James","email":"jrdegnan@usgs.gov","middleInitial":"R.","affiliations":[{"id":405,"text":"NH/VT office of New England Water Science Center","active":true,"usgs":true},{"id":466,"text":"New England Water Science Center","active":true,"usgs":true}],"preferred":true,"id":240639,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49903,"text":"ofr97214 - 1997 - Level II scour analysis for Bridge 80 (JAMAVT01000080) on State Highway 100, crossing the West River, Jamaica, Vermont","interactions":[],"lastModifiedDate":"2013-12-20T11:00:14","indexId":"ofr97214","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-214","title":"Level II scour analysis for Bridge 80 (JAMAVT01000080) on State Highway 100, crossing the West River, Jamaica, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nJAMAVT01000080 on State Route 100 crossing the West River, Jamaica, Vermont \n(figures 1–8). A Level II study is a basic engineering analysis of the site, including a \nquantitative analysis of stream stability and scour (U.S. Department of Transportation, \n1993). Results of a Level I scour investigation also are included in Appendix E of this \nreport. A Level I investigation provides a qualitative geomorphic characterization of the \nstudy site. Information on the bridge, gleaned from Vermont Agency of Transportation \n(VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is \nfound in Appendix D.\nThe site is in the Green Mountain section of the New England physiographic province in \nsouthern Vermont. The 227-mi2\n drainage area is in a predominantly rural and forested \nbasin. In the vicinity of the study site, the surface cover is pasture on the upstream left bank \nand downstream of the bridge while the immediate banks have dense woody vegetation. \nThe upstream right bank of the bridge is forested.\nIn the study area, the West River has an incised, straight channel with a slope of \napproximately 0.01 ft/ft, an average channel top width of 309 ft and an average bank height \nof 10 ft. The channel bed material is predominantly cobble with a median grain size (D50) \nof 109 mm (0.359 ft). The geomorphic assessment at the time of the Level I and Level II \nsite visit on August 13, 1996, indicated that the reach was stable.\nThe State Route 100 crossing of the West River is a 246-ft-long, one-lane steel thru-truss \nbridge consisting of three spans, the longest is 161-feet (Vermont Agency of \nTransportation, written communication, March 30, 1995). The bridge is supported by \nvertical, concrete abutments and two piers. The channel is skewed approximately 5 degrees \nto the opening while there is no opening-skew-to-roadway. \nA scour hole 3 ft deeper than the mean thalweg depth was observed along the streamward \n(right) side of the left pier during the Level I assessment. A scour hole 5 ft deeper than the \nmean thalweg depth was observed along the streamward (left) side of the right pier during \nthe Level I assessment. The only scour protection measure at the site was type-2 stone fill \n(less than 36 inches diameter) along the left and right bank below the abutments forming a \n“spill-through” slope at each abutment. Additional details describing conditions at the site \nare included in the Level II Summary and Appendices D and E.\nScour depths and recommended rock rip-rap sizes were computed using the general \nguidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995). \nTotal scour at a highway crossing is comprised of three components: 1) long-term \nstreambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction \nin flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and \nabutments). Total scour is the sum of the three components. Equations are available to \ncompute depths for contraction and local scour and a summary of the results of these \ncomputations follows.\nThere was no computed contraction scour. Abutment scour ranged from 15.8 to 23.9 ft. \nThe worst-case abutment scour occurred at the 500-year discharge. Pier scour ranged from \n9.5 to 22.8 ft. The worst-case pier scour occurred at the 500-year discharge. Additional \ninformation on scour depths and depths to armoring are included in the section titled “Scour \nResults”. Scoured-streambed elevations, based on the calculated scour depths, are presented \nin tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure \n8. Scour depths were calculated assuming an infinite depth of erosive material and a \nhomogeneous particle-size distribution. \nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr97214","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Ivanoff, M.A., and Degnan, J.R., 1997, Level II scour analysis for Bridge 80 (JAMAVT01000080) on State Highway 100, crossing the West River, Jamaica, Vermont: U.S. Geological Survey Open-File Report 97-214, iv, 52 p., https://doi.org/10.3133/ofr97214.","productDescription":"iv, 52 p.","numberOfPages":"57","costCenters":[],"links":[{"id":169641,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97214.PNG"},{"id":279799,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0214/report.pdf"}],"scale":"25000","country":"United States","state":"Vermont","city":"Jamaica","otherGeospatial":"West River","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.75,43.0 ], [ -72.75,43.125 ], [ -72.5,43.125 ], [ -72.5,43.0 ], [ -72.75,43.0 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b16e4b07f02db6a55ff","contributors":{"authors":[{"text":"Ivanoff, Michael A.","contributorId":27105,"corporation":false,"usgs":true,"family":"Ivanoff","given":"Michael","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":240453,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Degnan, James R. 0000-0002-5665-9010 jrdegnan@usgs.gov","orcid":"https://orcid.org/0000-0002-5665-9010","contributorId":498,"corporation":false,"usgs":true,"family":"Degnan","given":"James","email":"jrdegnan@usgs.gov","middleInitial":"R.","affiliations":[{"id":405,"text":"NH/VT office of New England Water Science Center","active":true,"usgs":true},{"id":466,"text":"New England Water Science Center","active":true,"usgs":true}],"preferred":true,"id":240452,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49902,"text":"ofr97213 - 1997 - Level II scour analysis for Bridge 7 (CHARTH00010007) on Town Highway 1, crossing Mad Brook, Charleston, Vermont","interactions":[],"lastModifiedDate":"2013-12-20T11:20:57","indexId":"ofr97213","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-213","title":"Level II scour analysis for Bridge 7 (CHARTH00010007) on Town Highway 1, crossing Mad Brook, Charleston, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nCHARTH00010007 on town highway 1 crossing Mad Brook, Charleston, Vermont (figures \n1–8). A Level II study is a basic engineering analysis of the site, including a quantitative \nanalysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of \na Level I scour investigation also are included in Appendix E of this report. A Level I \ninvestigation provides a qualitative geomorphic characterization of the study site. \nInformation on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) \nfiles, was compiled prior to conducting Level I and Level II analyses and is found in \nAppendix D.\nThe site is in the White Mountain section of the New England physiographic province in \nnorth-central Vermont in the town of Charleston. The 6.59-mi2\n drainage area is in a \npredominantly rural and forested basin. In the vicinity of the study site, the surface cover is \npasture except for the upstream left bank, which is forest. The stream banks are tree covered \nupstream and on the downstream left bank side.\nIn the study area, Mad Brook has an incised, sinuous channel with a slope of approximately \n0.01 ft/ft, an average channel top width of 41 ft and an average channel depth of 5 ft. The \npredominant channel bed materials range from gravel to boulders with a median grain size \n(D50) of 105 mm (0.344 ft). The geomorphic assessment at the time of the Level I and Level \nII site visit on October 28, 1994, indicated that the reach was stable.\nThe town highway 1 crossing of Mad Brook is a 27-ft-long, two-lane bridge consisting of \none 25-foot concrete T-beam span (Vermont Agency of Transportation, written \ncommunication, August 4, 1994). The bridge is supported by vertical, concrete abutments \nwith wingwalls. The channel is skewed approximately 10 degrees to the opening. The \nopening-skew-to-roadway computed from surveyed data is 5 degrees, but historical bridge \nrecords indicate this angle is closer to 10 degrees.\nThere was scour evident during the Level I assessment due to the presence of two \nsubfootings at the base of each abutment wall. Although the subfootings may have been \nconstructed at the same time as the abutment walls, the subfootings may have been \nconstructed at a later time in response to streambed degradation under the bridge. The right \nabutment was noted as undermined during the Level I assessment. Scour protection \nmeasures at the site were type-1 stone fill (less than 12 inches diameter) on the upstream \nright and downstream road embankments and type-2 stone fill on each wingwall and the \ndownstream left bank. Additional details describing conditions at the site are included in the \nLevel II Summary and Appendices D and E.\nScour depths and rock rip-rap sizes were computed using the general guidelines described \nin Hydraulic Engineering Circular 18 (Richardson and others, 1995). Total scour at a \nhighway crossing is comprised of three components: 1) long-term streambed degradation; \n2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) \nand; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is \nthe sum of the three components. Equations are available to compute depths for contraction \nand local scour and a summary of the results of these computations follows.\nContraction scour for all modelled flows ranged from 0.0 to 0.3 ft. The worst-case \ncontraction scour occurred at the incipient overtopping discharge, which was less than the \n100-year discharge. Abutment scour ranged from 6.2 to 9.4 ft. The worst-case abutment \nscour for the right abutment was 9.4 feet at the 100-year discharge. The worst-case \nabutment scour for the left abutment was 8.6 feet at the incipient overtopping discharge. \nAdditional information on scour depths and depths to armoring are included in the section \ntitled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, \nare presented in tables 1 and 2. A cross-section of the scour computed at the bridge is \npresented in figure 8. Scour depths were calculated assuming an infinite depth of erosive \nmaterial and a homogeneous particle-size distribution. \n It is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr97213","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Boehmler, E.M., and Weber, M.A., 1997, Level II scour analysis for Bridge 7 (CHARTH00010007) on Town Highway 1, crossing Mad Brook, Charleston, Vermont: U.S. Geological Survey Open-File Report 97-213, iv, 50 p., https://doi.org/10.3133/ofr97213.","productDescription":"iv, 50 p.","numberOfPages":"55","costCenters":[],"links":[{"id":170453,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97213.PNG"},{"id":279801,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0213/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Charleston","otherGeospatial":"Mad Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.75,43.5 ], [ -72.75,43.625 ], [ -72.625,43.625 ], [ -72.625,43.5 ], [ -72.75,43.5 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b16e4b07f02db6a5749","contributors":{"authors":[{"text":"Boehmler, Erick M.","contributorId":96303,"corporation":false,"usgs":true,"family":"Boehmler","given":"Erick","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":240451,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Weber, Matthew A.","contributorId":41483,"corporation":false,"usgs":true,"family":"Weber","given":"Matthew","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":240450,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49901,"text":"ofr97212 - 1997 - Level II scour analysis for Bridge 19 (CHARTH00390019) on Town Highway 39, crossing Mad Brook, Charleston, Vermont","interactions":[],"lastModifiedDate":"2013-12-20T11:29:33","indexId":"ofr97212","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-212","title":"Level II scour analysis for Bridge 19 (CHARTH00390019) on Town Highway 39, crossing Mad Brook, Charleston, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure CHARTH00390019 on Town Highway 39 crossing Mad Brook, Charleston, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including a quantitative analysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of a Level I investigation also are included in this report in Appendix E. A Level I study provides a qualitative geomorphic characterization of the study site. Information on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is found in Appendix D.\nThe site is in the White Mountain section of the New England physiographic province in northeastern Vermont in the town of Charleston. The 6.54-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is forest except for the upstream left side which is covered primarily with shrubs and brush. The immediate banks have dense woody vegetation.\nIn the study area, Mad Brook has an incised, sinuous channel with a slope of approximately 0.023 ft/ft, an average channel top width of 40 ft and an average channel depth of 4 ft. The predominant channel bed material is cobble with a median grain size (D50) of 135.0 mm (0.443 ft). The geomorphic assessment on October 26, 1994 indicated that the reach was laterally unstable due to long-term lateral migration of the channel. Data collection for the level II analysis was accomplished on October 26, 1994 and July 24, 1995.\nThe Town Highway 39 crossing of Mad Brook is a 34-ft-long, two-lane bridge consisting of one 31-foot steel-beam span (Vermont Agency of Transportation, written communication, August 4, 1994). The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 40 degrees to the opening while the opening-skew-to-roadway is 45 degrees.\nA scour hole 1.5 ft deeper than the mean thalweg depth was observed along the right abutment during the Level I assessment. The scour protection measures evident at the site were type-2 stone fill (less than 36 inches diameter) on the upstream left wingwall and upstream end of the left abutment wall. Type-3 stone fill (less than 48 inches diameter) was\nnoted on the upstream right wingwall and the upstream side of the left road approach embankment. Additional details describing conditions at the site are included in the Level II Summary and Appendices D and E.\nScour depths and rock rip-rap sizes were computed using the general guidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995). Total scour at a highway crossing is comprised of three components: 1) long-term streambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is the sum of the three components. Equations are available to compute depths for contraction and local scour and a summary of the results of these computations follows.\nContraction scour for all modelled flows was 0.0 ft. Abutment scour ranged from 9.5 to 16.7 ft. The worst-case abutment scour occurred at the 500-year discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution.\nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, computed scour depths are evaluated in combination with other information including (but not limited to) historical performance during flood events, the geomorphic stability assessment, existing scour protection measures, and the results of the hydraulic analyses. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein.","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr97212","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Boehmler, E.M., and Hammond, R.E., 1997, Level II scour analysis for Bridge 19 (CHARTH00390019) on Town Highway 39, crossing Mad Brook, Charleston, Vermont: U.S. Geological Survey Open-File Report 97-212, iv, 47 p., https://doi.org/10.3133/ofr97212.","productDescription":"iv, 47 p.","numberOfPages":"52","costCenters":[],"links":[{"id":170452,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97212.PNG"},{"id":279802,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0212/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Charleston","otherGeospatial":"Mad Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.75,43.5 ], [ -72.75,43.625 ], [ -72.625,43.625 ], [ -72.625,43.5 ], [ -72.75,43.5 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b1ae4b07f02db6a81cf","contributors":{"authors":[{"text":"Boehmler, Erick M.","contributorId":96303,"corporation":false,"usgs":true,"family":"Boehmler","given":"Erick","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":240449,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Hammond, Robert E.","contributorId":61862,"corporation":false,"usgs":true,"family":"Hammond","given":"Robert","email":"","middleInitial":"E.","affiliations":[],"preferred":false,"id":240448,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":50017,"text":"ofr97793 - 1997 - Level II scour analysis for Bridge 5 (MORRTH00060005) on Town Highway 6, crossing Bedell Brook, Morristown, Vermont","interactions":[],"lastModifiedDate":"2013-12-17T14:06:39","indexId":"ofr97793","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-793","title":"Level II scour analysis for Bridge 5 (MORRTH00060005) on Town Highway 6, crossing Bedell Brook, Morristown, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nMORRTH00060005 on Town Highway 6 crossing Bedell Brook, Morristown, Vermont \n(figures 1–8). A Level II study is a basic engineering analysis of the site, including a \nquantitative analysis of stream stability and scour (U.S. Department of Transportation, \n1993). Results of a Level I scour investigation also are included in Appendix E of this \nreport. A Level I investigation provides a qualitative geomorphic characterization of the \nstudy site. Information on the bridge, gleaned from Vermont Agency of Transportation \n(VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is \nfound in Appendix D.\nThe site is in the Green Mountain section of the New England physiographic province in \nnorth-central Vermont. The 6.28-mi2\n drainage area is in a predominantly rural and forested \nbasin. In the vicinity of the study site, the surface cover consists of pasture, shrubs, and \nbrushland. \nIn the study area, Bedell Brook has a sinuous channel with a slope of approximately 0.01 ft/\nft, an average channel top width of 56 ft and an average bank height of 4 ft. The \npredominant channel bed material is gravel with a median grain size (D50) of 35.8 mm \n(0.117 ft). The geomorphic assessment at the time of the Level I and Level II site visit on \nJuly 16, 1996, indicated that the reach was laterally unstable. There are wide point bars and \ncut-banks with slipping bank material noted upstream and downstream of this site.\nThe Town Highway 6 crossing of Bedell Brook is a 44-ft-long, two-lane bridge consisting \nof one 42-foot concrete T-beam span (Vermont Agency of Transportation, written \ncommunication, October 26, 1995). The bridge is supported by vertical, concrete abutments \nwith wingwalls. The channel is skewed approximately 45 degrees to the opening while the \nopening-skew-to-roadway is zero degrees. \nA scour hole up to 1.5 ft deeper than the mean thalweg depth was observed along the left \nabutment and upstream and downstream left wingwalls during the Level I assessment. The \nscour protection measure at this site was type-4 stone fill (less than 60 inches diameter) on \nthe left bank and left wingwall upstream, the left abutment and the downstream left \nwingwall. Additional details describing conditions at the site are included in the Level II \nSummary and Appendices D and E.\nScour depths and recommended rock rip-rap sizes were computed using the general \nguidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995). \nTotal scour at a highway crossing is comprised of three components: 1) long-term \nstreambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction \nin flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and \nabutments). Total scour is the sum of the three components. Equations are available to \ncompute depths for contraction and local scour and a summary of the results of these \ncomputations follows.\nContraction scour for all modelled flows ranged from 1.1 to 2.0 feet. The worst-case \ncontraction scour occurred at the 500-year discharge. Abutment scour ranged from 3.9 to \n8.6 feet. The worst-case abutment scour occurred at the 500-year event. Additional \ninformation on scour depths and depths to armoring are included in the section titled “Scour \nResults”. Scoured-streambed elevations, based on the calculated scour depths, are presented \nin tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure \n8. Scour depths were calculated assuming an infinite depth of erosive material and a \nhomogeneous particle-size distribution. \nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr97793","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Boehmler, E.M., and Degnan, J.R., 1997, Level II scour analysis for Bridge 5 (MORRTH00060005) on Town Highway 6, crossing Bedell Brook, Morristown, Vermont: U.S. Geological Survey Open-File Report 97-793, iv, 47 p., https://doi.org/10.3133/ofr97793.","productDescription":"iv, 47 p.","numberOfPages":"52","costCenters":[],"links":[{"id":162934,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97793.PNG"},{"id":279662,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0793/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Morristown","otherGeospatial":"Bedell Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.625,44.5 ], [ -72.625,44.625 ], [ -72.5,44.625 ], [ -72.5,44.5 ], [ -72.625,44.5 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a5cf5","contributors":{"authors":[{"text":"Boehmler, Erick M.","contributorId":96303,"corporation":false,"usgs":true,"family":"Boehmler","given":"Erick","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":240642,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Degnan, James R. 0000-0002-5665-9010 jrdegnan@usgs.gov","orcid":"https://orcid.org/0000-0002-5665-9010","contributorId":498,"corporation":false,"usgs":true,"family":"Degnan","given":"James","email":"jrdegnan@usgs.gov","middleInitial":"R.","affiliations":[{"id":405,"text":"NH/VT office of New England Water Science Center","active":true,"usgs":true},{"id":466,"text":"New England Water Science Center","active":true,"usgs":true}],"preferred":true,"id":240641,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":50018,"text":"ofr97794 - 1997 - Level II scour analysis for Bridge 39 (STOWTH00160039) on Town Highway 16, crossing Moss Glen Brook, Stowe, Vermont","interactions":[],"lastModifiedDate":"2013-12-17T13:56:53","indexId":"ofr97794","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-794","title":"Level II scour analysis for Bridge 39 (STOWTH00160039) on Town Highway 16, crossing Moss Glen Brook, Stowe, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure STOWTH00160039 on Town Highway 16 crossing Moss Glen Brook, Stowe, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including a quantitative analysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of a Level I scour investigation also are included in Appendix E of this report. A Level I investigation provides a qualitative geomorphic characterization of the study site. Information on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is found in Appendix D.\nThe site is in the Green Mountain section of the New England physiographic province in north-central Vermont. The 4.75-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is forest upstream and on the right bank downstream. The downstream left bank is pasture while the immediate bank has dense woody vegetation.\nIn the study area, Moss Glen Brook has an incised, sinuous channel with a slope of approximately 0.02 ft/ft, an average channel top width of 52 ft and an average bank height of 7 ft. The channel bed material ranges from sand to cobble with a median grain size (D50) of 56.5 mm (0.185 ft). The geomorphic assessment at the time of the Level I and Level II site visit on July 10, 1996, indicated that the reach was stable.\nThe Town Highway 16 crossing of Moss Glen Brook is a 22-ft-long galvanized plate arch culvert with an opening span width of 21 ft (Vermont Agency of Transportation, written communication, October 13, 1995). The opening length of the structure parallel to the culvert face is 20.6 ft. The culvert is supported by vertical, concrete abutments with no wingwalls. The channel is skewed approximately zero degrees to the opening. The opening skew-to-roadway value from the VTAOT database is 5 degrees while zero degrees was computed from surveyed points.\nThe only scour counter measure at the site was type-3 stone fill (less than 48 inches diameter) at the upstream and downstream ends of the left and right abutments and extending along the banks upstream and downstream. Additional details describing conditions at the site are included in the Level II Summary and Appendices D and E.\nScour depths and recommended rock rip-rap sizes were computed using the general guidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995) for the 100- and 500-year discharges. Total scour at a highway crossing is comprised of three components: 1) long-term streambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is the sum of the three components. Equations are available to compute depths for contraction and local scour and a summary of the results of these computations follows.\nContraction scour for all modelled flows ranged from 0.0 to 1.2 ft. The worst-case contraction scour occurred at the 500-year discharge. Left abutment scour ranged from 12.6 to 16.2 ft. Right abutment scour ranged from 12.1 to 14.3 ft. The worst-case abutment scour occurred at the 500-year discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution.\nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, computed scour depths are evaluated in combination with other information including (but not limited to) historical performance during flood events, the geomorphic stability assessment, existing scour protection measures, and the results of the hydraulic analyses. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein.","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr97794","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Ivanoff, M.A., and Hammond, R.E., 1997, Level II scour analysis for Bridge 39 (STOWTH00160039) on Town Highway 16, crossing Moss Glen Brook, Stowe, Vermont: U.S. Geological Survey Open-File Report 97-794, iv, 46 p., https://doi.org/10.3133/ofr97794.","productDescription":"iv, 46 p.","numberOfPages":"51","costCenters":[],"links":[{"id":161565,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97794.PNG"},{"id":279661,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0794/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Stowe","otherGeospatial":"Glen Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.75,44.375 ], [ -72.75,44.5 ], [ -72.625,44.5 ], [ -72.625,44.375 ], [ -72.75,44.375 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a62bb","contributors":{"authors":[{"text":"Ivanoff, Michael A.","contributorId":27105,"corporation":false,"usgs":true,"family":"Ivanoff","given":"Michael","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":240643,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Hammond, Robert E.","contributorId":61862,"corporation":false,"usgs":true,"family":"Hammond","given":"Robert","email":"","middleInitial":"E.","affiliations":[],"preferred":false,"id":240644,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49900,"text":"ofr97211 - 1997 - Level II scour analysis for Bridge 2 (STAMVT01000002) on State Route 100 crossing Roaring Brook, Stamford, Vermont","interactions":[],"lastModifiedDate":"2013-12-20T11:39:58","indexId":"ofr97211","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-211","title":"Level II scour analysis for Bridge 2 (STAMVT01000002) on State Route 100 crossing Roaring Brook, Stamford, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nSTAMVT01000002 on State Route 100 crossing Roaring Brook, Stamford, Vermont \n(figures 1–8). A Level II study is a basic engineering analysis of the site, including a \nquantitative analysis of stream stability and scour (U.S. Department of Transportation, \n1993). Results of a Level I scour investigation also are included in Appendix E of this \nreport. A Level I investigation provides a qualitative geomorphic characterization of the \nstudy site. Information on the bridge, gleaned from Vermont Agency of Transportation \n(VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is \nfound in Appendix D.\nThe site is in the Green Mountain section of the New England physiographic province in \nSouthwestern Vermont. The 8.26-mi2\n drainage area is in a predominantly rural and forested \nbasin. In the vicinity of the study site, the surface cover consists of houses with grass lawns, \nand trees on the right overbank areas upstream and downstream of the bridge. The left \noverbank areas upstream and downstream of the bridge are covered with trees and brush.\nIn the study area, Roaring Brook has a straight channel with a slope of approximately 0.02 \nft/ft, an average channel top width of 56 ft and an average bank height of 5 ft. The channel \nbed materials range from gravel to boulders with a median grain size (D50) of 53.7 mm \n(0.176 ft). The geomorphic assessment at the time of the Level I and Level II site visit on \nJuly 31, 1996, indicated that the reach was aggraded.\nThe State Route 100 crossing of Roaring Brook is a 44-ft-long, two-lane bridge consisting \nof one 42-foot steel-beam span (Vermont Agency of Transportation, written \ncommunication, September 28, 1995). The bridge is supported by vertical, concrete \nabutments with wingwalls. The channel is skewed approximately 5 degrees to the opening \nand the opening-skew-to-roadway is 5 degrees. \nScour protection measures at the site were type-2 stone fill (less than 36 inches diameter) on \nthe upstream banks and wingwalls, type-3 (less than 48 inches diameter) on the downstream \nwingwalls, and artificial levees made from a variety of materials on the downstream banks. \nAdditional details describing conditions at the site are included in the Level II Summary \nand Appendices D and E.\nScour depths and rock rip-rap sizes were computed using the general guidelines described \nin Hydraulic Engineering Circular 18 (Richardson and others, 1995). Total scour at a \nhighway crossing is comprised of three components: 1) long-term streambed degradation; \n2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) \nand; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is \nthe sum of the three components. Equations are available to compute depths for contraction \nand local scour and a summary of the results of these computations follows.\nContraction scour for all modelled flows ranged from 0.0 to 0.8 feet. The worst-case \ncontraction scour occurred at the 100-year discharge. Abutment scour ranged from 4.2 to \n9.3 feet. The worst-case abutment scour occurred at the 500-year discharge at the left \nabutment. Additional information on scour depths and depths to armoring are included in \nthe section titled “Scour Results”. Scoured-streambed elevations, based on the calculated \nscour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the \nbridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of \nerosive material and a homogeneous particle-size distribution. \nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr97211","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Boehmler, E.M., and Hammond, R.E., 1997, Level II scour analysis for Bridge 2 (STAMVT01000002) on State Route 100 crossing Roaring Brook, Stamford, Vermont: U.S. Geological Survey Open-File Report 97-211, iv, 49 p., https://doi.org/10.3133/ofr97211.","productDescription":"iv, 49 p.","numberOfPages":"54","costCenters":[],"links":[{"id":170451,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97211.PNG"},{"id":279803,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0211/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Stamford","otherGeospatial":"Roaring Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.75,43.5 ], [ -72.75,43.625 ], [ -72.625,43.625 ], [ -72.625,43.5 ], [ -72.75,43.5 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b1ae4b07f02db6a817f","contributors":{"authors":[{"text":"Boehmler, Erick M.","contributorId":96303,"corporation":false,"usgs":true,"family":"Boehmler","given":"Erick","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":240447,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Hammond, Robert E.","contributorId":61862,"corporation":false,"usgs":true,"family":"Hammond","given":"Robert","email":"","middleInitial":"E.","affiliations":[],"preferred":false,"id":240446,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":50019,"text":"ofr97795 - 1997 - Level II scour analysis for Bridge 23 (WEELTH00210023) on Town Highway 21, crossing Miller Run, Wheelock, Vermont","interactions":[],"lastModifiedDate":"2013-12-17T13:42:50","indexId":"ofr97795","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-795","title":"Level II scour analysis for Bridge 23 (WEELTH00210023) on Town Highway 21, crossing Miller Run, Wheelock, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nWEELTH00210023 on Town Highway 21 crossing Miller Run, Wheelock, Vermont \n(figures 1–8). A Level II study is a basic engineering analysis of the site, including a \nquantitative analysis of stream stability and scour (U.S. Department of Transportation, \n1993). Results of a Level I scour investigation also are included in Appendix E of this \nreport. A Level I investigation provides a qualitative geomorphic characterization of the \nstudy site. Information on the bridge, gleaned from Vermont Agency of Transportation \n(VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is \nfound in Appendix D.\nThe site is in the New England Upland section of the New England physiographic province \nin northeastern Vermont. The 28.3-mi2\n drainage area is in a predominantly rural and \nforested basin. In the vicinity of the study site, the surface cover is forest on the upstream \nand downstream right banks while the surface cover on the upstream and downstream left \nbanks consists primarily of short grass and buildings with shrubs, brush and trees along the \nimmediate banks. \nIn the study area, Miller Run has an incised, straight channel with a slope of approximately \n0.003 ft/ft, an average channel top width of 76 ft and an average bank height of 6 ft. The \nchannel bed material ranges from gravel to boulder with a median grain size (D50) of 67.5 \nmm (0.221 ft). The geomorphic assessment at the time of the Level I and Level II site visit \non August 2, 1995, indicated that the reach was stable.\nThe Town Highway 21 crossing of Miller Run is a 46-ft-long, one-lane bridge consisting of \none 43-foot steel-beam span with a wooden deck (Vermont Agency of Transportation, \nwritten communication, April 5, 1995). The opening length of the structure parallel to the \nbridge face is 42.1 ft. The bridge is supported by vertical, concrete abutments with \nwingwalls. The channel is skewed approximately 20 degrees to the opening while the \ncomputed opening-skew-to-roadway is 25 degrees. \nA scour hole 1.0 ft deeper than the mean thalweg depth was observed under the bridge, \nalong the center of the channel, during the Level I assessment. The scour protection \nmeasures at the site included type-2 stone fill (less than 36 inches diameter) along the \ndownstream left bank and along the entire base length of the upstream and downstream \nright wingwalls. Type-3 stone fill (less than 48 inches diameter) protection was observed \nalong the upstream end of the upstream left wingwall and randomly scattered along the left \nabutment. Type-4 stone fill (less than 60 inches diameter) protection was observed along \nthe entire base length of the downstream left wingwall. Additional details describing \nconditions at the site are included in the Level II Summary and Appendices D and E.\nScour depths and recommended rock rip-rap sizes were computed using the general \nguidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995) \nfor the 100- and 500-year discharges. In addition, the incipient roadway-overtopping \ndischarge is determined and analyzed as another potential worst-case scour scenario. Total \nscour at a highway crossing is comprised of three components: 1) long-term streambed \ndegradation; 2) contraction scour (due to accelerated flow caused by a reduction in flow \narea at a bridge) and; 3) local scour (caused by accelerated flow around piers and \nabutments). Total scour is the sum of the three components. Equations are available to \ncompute depths for contraction and local scour and a summary of the results of these \ncomputations follows.\nContraction scour for all modelled flows was computed to be zero ft. Abutment scour \nranged from 9.1 to 10.8 ft along the right abutment and from 9.8 to 12.3 ft along the left \nabutment. The worst-case abutment scour occurred at the 500-year discharge. Additional \ninformation on scour depths and depths to armoring are included in the section titled “Scour \nResults”. Scoured-streambed elevations, based on the calculated scour depths, are presented \nin tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure \n8. Scour depths were calculated assuming an infinite depth of erosive material and a \nhomogeneous particle-size distribution. \nUsually, computed scour depths are evaluated in combination with other information \nincluding (but not limited to) historical performance during flood events, the geomorphic \nstability assessment, existing scour protection measures, and the results of the hydraulic \nanalyses. Therefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Reston, VA","doi":"10.3133/ofr97795","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Flynn, R.H., and Boehmler, E.M., 1997, Level II scour analysis for Bridge 23 (WEELTH00210023) on Town Highway 21, crossing Miller Run, Wheelock, Vermont: U.S. Geological Survey Open-File Report 97-795, iv, 50 p., https://doi.org/10.3133/ofr97795.","productDescription":"iv, 50 p.","numberOfPages":"55","costCenters":[],"links":[{"id":161566,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97795.PNG"},{"id":279660,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0795/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Wheelock","otherGeospatial":"Miller Run","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.125,44.5 ], [ -72.125,44.625 ], [ -72.0,44.625 ], [ -72.0,44.5 ], [ -72.125,44.5 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b1ae4b07f02db6a80cd","contributors":{"authors":[{"text":"Flynn, Robert H. rflynn@usgs.gov","contributorId":2137,"corporation":false,"usgs":true,"family":"Flynn","given":"Robert","email":"rflynn@usgs.gov","middleInitial":"H.","affiliations":[{"id":405,"text":"NH/VT office of New England Water Science Center","active":true,"usgs":true}],"preferred":true,"id":240645,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Boehmler, Erick M.","contributorId":96303,"corporation":false,"usgs":true,"family":"Boehmler","given":"Erick","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":240646,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":50020,"text":"ofr97796 - 1997 - Level II scour analysis for Bridge 25 (DANVTH00610025) on Town Highway 61, crossing Water Andric Brook, Danville, Vermont","interactions":[],"lastModifiedDate":"2013-12-17T13:35:16","indexId":"ofr97796","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-796","title":"Level II scour analysis for Bridge 25 (DANVTH00610025) on Town Highway 61, crossing Water Andric Brook, Danville, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nDANVTH00610025 on Town Highway 61 crossing Water Andric Brook, Danville, \nVermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including \na quantitative analysis of stream stability and scour (U.S. Department of Transportation, \n1993). Results of a Level I scour investigation also are included in Appendix E of this \nreport. A Level I investigation provides a qualitative geomorphic characterization of the \nstudy site. Information on the bridge, gleaned from Vermont Agency of Transportation \n(VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is \nfound in Appendix D.\nThe site is in the New England Upland section of the New England physiographic province \nin northeastern Vermont. The 9.69-mi2\n drainage area is in a predominantly rural and \nforested basin. In the vicinity of the study site, the surface cover is pasture on the \ndownstream left bank while the upstream right bank is grass with trees along the immediate \nbanks. The downstream right bank and upstream left bank are forested.\nIn the study area, Water Andric Brook has a straight channel with a slope of approximately \n0.007 ft/ft, an average channel top width of 45 ft and an average bank height of 4 ft. The \npredominant channel bed material is gravel with a median grain size (D50) of 53.4 mm \n(0.175 ft). The geomorphic assessment at the time of the Level I and Level II site visit on \nAugust 22, 1995, indicated that the reach was stable.\nThe Town Highway 61 crossing of Water Andric Brook is a 24-ft-long, two-lane bridge \nconsisting of one 22-foot concrete slab span (Vermont Agency of Transportation, written \ncommunication, March 24, 1995). The opening length of the structure parallel to the bridge \nface is 22.9 ft. The bridge is supported by vertical, concrete abutments with wingwalls. The \nchannel is skewed approximately 5 degrees to the opening and the computed opening-skewto-roadway is 5 degrees. The VTAOT computed opening-skew-to-roadway is zero degrees. \nA scour hole 0.5 ft deeper than the mean thalweg depth was observed along the upstream \nhalf of the left abutment during the Level I assessment. The only scour protection measure \nat the site was type-2 stone fill (less than 36 inches diameter) at the upstream end of the \nupstream left wingwall. Additional details describing conditions at the site are included in \nthe Level II Summary and Appendices \nD and E.\nScour depths and recommended rock rip-rap sizes were computed using the general \nguidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995) \nfor the 100- and 500-year discharges. In addition, the incipient roadway-overtopping \ndischarge is determined and analyzed as another potential worst-case scour scenario. Total \nscour at a highway crossing is comprised of three components: 1) long-term streambed \ndegradation; 2) contraction scour (due to accelerated flow caused by a reduction in flow \narea at a bridge) and; 3) local scour (caused by accelerated flow around piers and \nabutments). Total scour is the sum of the three components. Equations are available to \ncompute depths for contraction and local scour and a summary of the results of these \ncomputations follows.\nContraction scour for all modelled flows ranged from 0.7 to 1.3 ft. The worst-case \ncontraction scour occurred at the 500-year discharge. Abutment scour ranged from 9.1 to \n12.5 ft. The worst-case abutment scour occurred at the 500-year discharge. Additional \ninformation on scour depths and depths to armoring are included in the section titled “Scour \nResults”. Scoured-streambed elevations, based on the calculated scour depths, are presented \nin tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure \n8. Scour depths were calculated assuming an infinite depth of erosive material and a \nhomogeneous particle-size distribution. \nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr97796","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Flynn, R.H., and Severance, T., 1997, Level II scour analysis for Bridge 25 (DANVTH00610025) on Town Highway 61, crossing Water Andric Brook, Danville, Vermont: U.S. Geological Survey Open-File Report 97-796, iv, 50 p., https://doi.org/10.3133/ofr97796.","productDescription":"iv, 50 p.","numberOfPages":"55","costCenters":[],"links":[{"id":161567,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97796.PNG"},{"id":279643,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0796/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Danville","otherGeospatial":"Water Andric Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.25,44.375 ], [ -72.25,44.5 ], [ -72.0,44.5 ], [ -72.0,44.375 ], [ -72.25,44.375 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b1ae4b07f02db6a8034","contributors":{"authors":[{"text":"Flynn, Robert H. rflynn@usgs.gov","contributorId":2137,"corporation":false,"usgs":true,"family":"Flynn","given":"Robert","email":"rflynn@usgs.gov","middleInitial":"H.","affiliations":[{"id":405,"text":"NH/VT office of New England Water Science Center","active":true,"usgs":true}],"preferred":true,"id":240647,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Severance, Timothy","contributorId":104927,"corporation":false,"usgs":true,"family":"Severance","given":"Timothy","email":"","affiliations":[],"preferred":false,"id":240648,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":50021,"text":"ofr97797 - 1997 - Level II scour analysis for Bridge 39 (TOPSTH00510039) on Town Highway 51, crossing Tabor Branch Waits River, Topsham, Vermont","interactions":[],"lastModifiedDate":"2013-12-17T13:28:05","indexId":"ofr97797","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-797","title":"Level II scour analysis for Bridge 39 (TOPSTH00510039) on Town Highway 51, crossing Tabor Branch Waits River, Topsham, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nTOPSTH00510039 on Town Highway 51 crossing the Tabor Branch Waits River, \nTopsham, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the \nsite, including a quantitative analysis of stream stability and scour (U.S. Department of \nTransportation, 1993). Results of a Level I scour investigation also are included in \nAppendix E of this report. A Level I investigation provides a qualitative geomorphic \ncharacterization of the study site. Information on the bridge, gleaned from Vermont Agency \nof Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II \nanalyses and is found in Appendix D.\nThe site is in the New England Upland section of the New England physiographic province \nin east-central Vermont. The 17.4-mi2\n drainage area is in a predominantly rural and forested \nbasin. In the vicinity of the study site, the surface cover is predominantly pasture. However, \nbeyond one bridge length on the right bank upstream the surface cover abruptly changes to \nforest.\nIn the study area, the Tabor Branch Waits River has a sinuous channel with a slope of \napproximately 0.01 ft/ft, an average channel top width of 53 ft and an average bank height \nof 6 ft. The predominant channel bed material is cobbles with a median grain size (D50) of \n86.4 mm (0.283 ft). The geomorphic assessment at the time of the Level I and Level II site \nvisit on August 30, 1995, indicated that the reach was stable.\nThe Town Highway 51 crossing of the Tabor Branch Waits River is a 34-ft-long, one-lane \nbridge consisting of one 32-foot concrete slab span (Vermont Agency of Transportation, \nwritten communication, March 28, 1995). The opening length of the structure parallel to the \nbridge face is 31.0 ft. The bridge is supported by vertical, concrete abutments with \nwingwalls. The channel is skewed approximately 5 degrees to the opening while the \nopening-skew-to-roadway is 10 degrees.\nThe only scour protection measure at the site was type-2 stone fill (less than 36 inches \ndiameter) along the left and right bank upstream, along the base of the upstream left \nwingwall, upstream right wingwall, left abutment, right abutment, downstream left \nwingwall, downstream right wingwall, and along the left and right bank downstream. \nAdditional details describing conditions at the site are included in the Level II Summary \nand Appendices D and E.\nScour depths and recommended rock rip-rap sizes were computed using the general \nguidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995) \nfor the 100- and 500-year discharges. In addition, the incipient roadway-overtopping \ndischarge is determined and analyzed as another potential worst-case scour scenario. Total \nscour at a highway crossing is comprised of three components: 1) long-term streambed \ndegradation; 2) contraction scour (due to accelerated flow caused by a reduction in flow \narea at a bridge) and; 3) local scour (caused by accelerated flow around piers and \nabutments). Total scour is the sum of the three components. Equations are available to \ncompute depths for contraction and local scour and a summary of the results of these \ncomputations follows.\nContraction scour for all modelled flows ranged from 0.0 to 0.4 ft. The worst-case \ncontraction scour occurred at the maximum free surface flow discharge, which was less \nthan the 100-year discharge. Abutment scour ranged from 4.8 to 8.0 ft. The worst-case \nabutment scour occurred at 500-year discharge. Additional information on scour depths and \ndepths to armoring are included in the section titled “Scour Results”. Scoured-streambed \nelevations, based on the calculated scour depths, are presented in tables 1 and 2. A crosssection of the scour computed at the bridge is presented in figure 8. Scour depths were \ncalculated assuming an infinite depth of erosive material and a homogeneous particle-size \ndistribution. \nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr97797","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Striker, L.K., and Severance, T., 1997, Level II scour analysis for Bridge 39 (TOPSTH00510039) on Town Highway 51, crossing Tabor Branch Waits River, Topsham, Vermont: U.S. Geological Survey Open-File Report 97-797, iv, 51 p., https://doi.org/10.3133/ofr97797.","productDescription":"iv, 51 p.","numberOfPages":"56","costCenters":[],"links":[{"id":161568,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97797.PNG"},{"id":279642,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0797/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Topsham","otherGeospatial":"Tabor Branch Waits River","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.25,44.0 ], [ -72.25,44.125 ], [ -72.125,44.125 ], [ -72.125,44.0 ], [ -72.25,44.0 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a620f","contributors":{"authors":[{"text":"Striker, Lora K.","contributorId":41481,"corporation":false,"usgs":true,"family":"Striker","given":"Lora","email":"","middleInitial":"K.","affiliations":[],"preferred":false,"id":240649,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Severance, Tim","contributorId":53851,"corporation":false,"usgs":true,"family":"Severance","given":"Tim","affiliations":[],"preferred":false,"id":240650,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49899,"text":"ofr97210 - 1997 - Level II scour analysis for Bridge 30 (BRNATH00470030) on Town Highway 47, crossing Locust Creek, Barnard, Vermont","interactions":[],"lastModifiedDate":"2013-12-20T11:44:44","indexId":"ofr97210","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-210","title":"Level II scour analysis for Bridge 30 (BRNATH00470030) on Town Highway 47, crossing Locust Creek, Barnard, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nBRNATH00470030 on Town Highway 47 crossing Locust Creek, Barnard, Vermont \n(figures 1–8). A Level II study is a basic engineering analysis of the site, including a \nquantitative analysis of stream stability and scour (U.S. Department of Transportation, \n1993). Results of a Level I scour investigation also are included in Appendix E of this \nreport. A Level I investigation provides a qualitative geomorphic characterization of the \nstudy site. Information on the bridge, gleaned from Vermont Agency of Transportation \n(VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is \nfound in Appendix D.\nThe site is in the Green Mountain section of the New England physiographic province in \ncentral Vermont. The 4.18-mi2\n drainage area is a predominantly rural and forested basin. In \nthe vicinity of the study site, the surface cover consists of trees, shrubs, and brush.\nIn the study area, Locust Creek has an incised, sinuous channel with a slope of \napproximately 0.02 ft/ft, an average channel top width of 32 ft and an average bank height \nof 4 ft. The predominant channel bed material is gravel with a median grain size (D50) of \n49.5 mm (0.162 ft). The geomorphic assessment at the time of the Level I and Level II site \nvisit on October 13, 1994, indicated that the reach was stable.\nThe Town Highway 47 crossing of Locust Creek is a 28-ft-long, one-lane bridge consisting \nof one 25-foot concrete span (Vermont Agency of Transportation, written communication, \nAugust 23, 1994). The bridge is supported by vertical, concrete abutments with wingwalls. \nThe channel is skewed approximately 40 degrees to the opening. Historical bridge data \nindicates that the opening-skew-to-roadway is 45 degrees, but 35 degrees was computed by \nuse of survey data from this study.\nA minor scour hole, 0.5 ft deeper than the mean thalweg depth was observed along the left \nabutment wall during the Level I assessment. The scour protection measures at the site were \ntype-2 stone fill (less than 36 inches diameter) on the upstream wingwalls. There also is \ntype-3 stone fill on the downstream right wingwall. Additional details describing conditions \nat the site are included in the Level II Summary and Appendices D and E.\nScour depths and recommended rock rip-rap sizes were computed using the general \nguidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995). \nTotal scour at a highway crossing is comprised of three components: 1) long-term \nstreambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction \nin flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and \nabutments). Total scour is the sum of the three components. Equations are available to \ncompute depths for contraction and local scour and a summary of the results of these \ncomputations follows.\nContraction scour for all modelled flows ranged from 0.0 to 1.4 feet. The worst-case \ncontraction scour occurred at the 500-year discharge. Abutment scour ranged from 2.3 to \n8.9 feet. The worst-case abutment scour occurred at the 100-year discharge at the right \nabutment. Additional information on scour depths and depths to armoring are included in \nthe section titled “Scour Results”. Scoured-streambed elevations, based on the calculated \nscour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the \nbridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of \nerosive material and a homogeneous particle-size distribution. \nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr97210","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Boehmler, E.M., and Song, D.L., 1997, Level II scour analysis for Bridge 30 (BRNATH00470030) on Town Highway 47, crossing Locust Creek, Barnard, Vermont: U.S. Geological Survey Open-File Report 97-210, iv, 49 p., https://doi.org/10.3133/ofr97210.","productDescription":"iv, 49 p.","numberOfPages":"54","costCenters":[],"links":[{"id":170387,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97210.PNG"},{"id":279804,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0210/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Barnard","otherGeospatial":"Locust Creek","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.75,43.625 ], [ -72.75,43.75 ], [ -72.625,43.75 ], [ -72.625,43.625 ], [ -72.75,43.625 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b19e4b07f02db6a7eeb","contributors":{"authors":[{"text":"Boehmler, Erick M.","contributorId":96303,"corporation":false,"usgs":true,"family":"Boehmler","given":"Erick","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":240444,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Song, Donald L.","contributorId":107335,"corporation":false,"usgs":true,"family":"Song","given":"Donald","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":240445,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":50022,"text":"ofr97798 - 1997 - Level II scour analysis for Bridge 50 (STARTH00250050) on Town Highway 25, crossing Lewis Creek, Starksboro, Vermont","interactions":[],"lastModifiedDate":"2013-12-17T13:20:14","indexId":"ofr97798","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-798","title":"Level II scour analysis for Bridge 50 (STARTH00250050) on Town Highway 25, crossing Lewis Creek, Starksboro, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nSTARTH00250050 on Town Highway 25 crossing Lewis Creek, Starksboro, Vermont \n(figures 1–8). A Level II study is a basic engineering analysis of the site, including a \nquantitative analysis of stream stability and scour (U.S. Department of Transportation, \n1993). Results of a Level I scour investigation also are included in Appendix E of this \nreport. A Level I investigation provides a qualitative geomorphic characterization of the \nstudy site. Information on the bridge, gleaned from Vermont Agency of Transportation \n(VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is \nfound in Appendix D.\nThe site is in the Green Mountain section of the New England physiographic province in \nwest-central Vermont. The 10.9-mi2\n drainage area is in a predominantly rural and forested \nbasin. In the vicinity of the study site, the surface cover is pasture on the left bank \ndownstream and upstream of the bridge. On the right bank upstream and downstream of the \nbridge the surface cover is forest.\nIn the study area, Lewis Creek has an incised, straight channel with a slope of \napproximately 0.007 ft/ft, an average channel top width of 64 ft and an average bank height \nof 7 ft. The channel bed material ranges from sand to boulder with a median grain size (D50) \nof 35.4 mm (0.116 ft). The geomorphic assessment at the time of the Level I and Level II \nsite visit on June 12, 1996, indicated that the reach was stable.\nThe Town Highway 25 crossing of Lewis Creek is a 28-ft-long, one-lane bridge consisting \nof one 25-foot steel-beam span (Vermont Agency of Transportation, written \ncommunication, December 15, 1995). The opening length of the structure parallel to the \nbridge face is 23.8 ft. The bridge is supported by vertical, concrete abutments with \nwingwalls on all corners except the downstream left. The channel is skewed approximately \nzero degrees to the opening and the opening-skew-to-roadway is also zero degrees. \nA scour hole 1.0 ft deeper than the mean thalweg depth was observed along the right \nabutment during the Level I assessment. Also, the footing is exposed along the left and right \nabutments and all three wingwalls. The scour countermeasures at the site included type-1 \nstone fill (less than 12 inches diameter) along the left abutment and type-2 stone fill (less \nthan 36 inches diameter) along the right abutment and the upstream and downstream right \nwingwalls. Additional details describing conditions at the site are included in the Level II \nSummary and Appendices D and E.\nScour depths and recommended rock rip-rap sizes were computed using the general \nguidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995) \nfor the 100- and 500-year discharges. In addition, the incipient roadway-overtopping \ndischarge was determined and analyzed as another potential worst-case scour scenario. \nTotal scour at a highway crossing is comprised of three components: 1) long-term \nstreambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction \nin flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and \nabutments). Total scour is the sum of the three components. Equations are available to \ncompute depths for contraction and local scour and a summary of the results of these \ncomputations follows.\nContraction scour for all modelled flows ranged from 5.2 to 9.1 ft. The worst-case \ncontraction scour occurred at the 500-year discharge. Abutment scour ranged from 13.1 to \n18.2 ft. The worst-case abutment scour occurred at the 500-year discharge. Additional \ninformation on scour depths and depths to armoring are included in the section titled “Scour \nResults”. Scoured-streambed elevations, based on the calculated scour depths, are presented \nin tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure \n8. Scour depths were calculated assuming an infinite depth of erosive material and a \nhomogeneous particle-size distribution. \nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr97798","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Burns, R.L., and Boehmler, E.M., 1997, Level II scour analysis for Bridge 50 (STARTH00250050) on Town Highway 25, crossing Lewis Creek, Starksboro, Vermont: U.S. Geological Survey Open-File Report 97-798, iv, 51 p., https://doi.org/10.3133/ofr97798.","productDescription":"iv, 51 p.","numberOfPages":"56","costCenters":[],"links":[{"id":161569,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97798.PNG"},{"id":279641,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0798/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Starksboro","otherGeospatial":"Lewis Creek","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.75,43.5 ], [ -72.75,43.625 ], [ -72.625,43.625 ], [ -72.625,43.5 ], [ -72.75,43.5 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a5b97","contributors":{"authors":[{"text":"Burns, Ronda L.","contributorId":71602,"corporation":false,"usgs":true,"family":"Burns","given":"Ronda","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":240651,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Boehmler, Erick M.","contributorId":96303,"corporation":false,"usgs":true,"family":"Boehmler","given":"Erick","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":240652,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ]}