This report provides the results of a detailed Level II analysis of scour potential at structure \nRANDTH00BR0054 on Brook Street crossing Thayer Brook, Randolph, 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). A Level \nI study is included in Appendix E of this report. A Level I study provides a qualitative \ngeomorphic characterization of the study site. Information on the bridge available from \nVTAOT files was compiled prior to conducting Level I and Level II analyses and can be \nfound in Appendix D.
\nThe site is in the Green Mountain physiographic division of central Vermont in the town of \nRandolph. The 5.39-mi2\n drainage area is in a predominantly rural basin. In the vicinity of \nthe study site, the immediate banks are forested.
\nIn the study area, Thayer Brook has an incised, sinuous channel with a slope of \napproximately 0.03 ft/ft, an average channel top width of 60 ft and an average channel \ndepth of 3 ft. The predominant channel bed materials are gravel and cobble (D50 is 42.4 mm \nor 0.139 ft). The geomorphic assessment at the time of the Level I and Level II site visits on \nAugust 3, 1994 and December 5, 1994, indicated that the reach was vertically and laterally \nunstable. This assessment was due to the extreme channel misalignment with the bridge \nopening and the presence of a drop structure downstream of the bridge protecting against \nchannel degradation.
\nThe Brook Street crossing of Thayer Brook is a 34-ft-long, two-lane bridge consisting of \none 31-foot concrete span (Vermont Agency of Transportation, written communication, \nAugust 2, 1994). The bridge is supported by vertical, concrete abutments with wingwalls. \nStreamflow attacks the upstream right wingwall and has undermined the upstream end of \nthe right abutment. Type-2 stone fill (less than 36 inches diameter) exists only on the \nupstream and downstream sides of the left road embankment. No other protection was \nnoted. The bank full channel skew at the bridge face is approximately 20 degrees; the \nopening-skew-to-roadway is also 20 degrees. Additional details describing conditions at the \nsite are included in the Level II Summary and Appendices D \nand E.
\nScour depths and rock rip-rap sizes were computed using the general guidelines described \nin Hydraulic Engineering Circular 18 (Richardson and others, 1993). 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 1.3 to 2.7 ft. The worst-case \ncontraction scour occurred at the 500-year discharge. Abutment scour ranged from 5.3 to \n15.1 ft. and the worst-case abutment scour also 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 8. 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, 1993, p. 48). Many factors, \nincluding historical performance during flood events, the geomorphic assessment, scour \nprotection measures, and the results of the hydraulic analyses, must be considered to \nproperly assess the validity of abutment scour results. Therefore, scour depths adopted by \nVTAOT may differ from the computed values documented herein, based on the \nconsideration of additional contributing factors and experienced engineering judgement.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr96308","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Olson, S.A., 1996, Level II scour analysis for Bridge 54 (RANDTH00BR0054) on Brook Street, crossing Thayer Brook, Randolph, Vermont: U.S. Geological Survey Open-File Report 96-308, iv, 27 p., https://doi.org/10.3133/ofr96308.","productDescription":"iv, 27 p.","numberOfPages":"32","costCenters":[],"links":[{"id":179405,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96308.GIF"},{"id":279375,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0308/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Randolph","otherGeospatial":"Thayer Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.75,43.875 ], [ -72.75,44.0 ], [ -72.625,44.0 ], [ -72.625,43.875 ], [ -72.75,43.875 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a5a8d","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":240292,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":49801,"text":"ofr96303 - 1996 - Level II scour analysis for Bridge 49 (BETHTH00790049) on Town Highway 79, crossing Locust Creek, Bethel, Vermont","interactions":[],"lastModifiedDate":"2013-12-11T10:27:41","indexId":"ofr96303","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1996","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":"96-303","title":"Level II scour analysis for Bridge 49 (BETHTH00790049) on Town Highway 79, crossing Locust Creek, Bethel, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nBETHTH00790049 on town highway 79 crossing Locust Creek, Bethel, 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). A Level \nI study is included in Appendix E of this report. A Level I study provides a qualitative \ngeomorphic characterization of the study site. Information on the bridge available from \nVTAOT files was compiled prior to conducting Level I and Level II analyses and can be \nfound in Appendix D.
\nThe site is in the Green Mountain physiographic province of central Vermont in the town of \nBethel. The 24.4-mi2\n drainage area is in a predominantly rural and forested basin. In the \nvicinity of the study site, the banks are forested.
\nIn the study area, Locust Creek has an incised, sinuous channel with a slope of \napproximately 0.015 ft/ft, an average channel top width of 74 ft and an average channel \ndepth of 6 ft. The predominant channel bed material is gravel and cobble (D50 is 124 mm or \n0.407 ft). The geomorphic assessment at the time of the Level I and Level II site visit on \nSeptember 21 & 26, 1994, respectively, with a check on\n 12/15/94, indicated that the reach was stable.
\nThe town Highway 79 crossing of Locust Creek is a 55-ft-long, one-lane bridge consisting \nof one 50-foot concrete span (Vermont Agency of Transportation, written commun., August \n24, 1994). The bridge is supported by vertical, concrete abutments with wingwalls. The \nchannel is skewed approximately 50 degrees to the opening while the opening-skew-toroadway is 45 degrees. \nScour protection measures in place at the site were type-1 stone fill (less than 12 inches \ndiameter) at the upstream right and downstream left road embankment, type-2 stone fill \n(less than 36 inches diameter) at the upstream left bank, upstream wingwalls, and \ndownstream left wingwall. Additional details describing conditions at the site are included \nin the Level II Summary and Appendices D\nand E.
\nScour depths and rock rip-rap sizes were computed using the general guidelines described \nin Hydraulic Engineering Circular 18 (Richardson and others, 1993).\nTotal scour at a highway crossing is comprised of three components: 1) long-term \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 these computed results \nfollow.
\nContraction scour for all modelled flows ranged from 0.0 ft to 1.0 ft. The worst-case \ncontraction scour occurred at the 100-year discharge. Abutment scour ranged from 10.3 ft \nto 13.3 ft. with the worst-case abutment scour also occurring at the 100-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 depths, are \npresented in tables 1 and 2. A cross-section of the computed scour at the bridge is presented \nin figure 8. Scour depths were calculated assuming an infinite depth of erosive material and \na homogeneous particle-size distribution.
\nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1993, p. 22). Many factors, \nincluding historical performance during flood events, the geomorphic assessment, scour \nprotection, and the results of the hydraulic analyses, must be considered to properly assess \nthe validity of abutment scour results. Therefore, scour depths adopted by VTAOT may \ndiffer from the computed values documented herein, based on the consideration of \nadditional contributing factors and experienced engineering judgement.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr96303","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Ivanoff, M.A., and Olson, S.A., 1996, Level II scour analysis for Bridge 49 (BETHTH00790049) on Town Highway 79, crossing Locust Creek, Bethel, Vermont: U.S. Geological Survey Open-File Report 96-303, iv, 30 p., https://doi.org/10.3133/ofr96303.","productDescription":"iv, 30 p.","numberOfPages":"35","costCenters":[],"links":[{"id":178823,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96303.GIF"},{"id":279380,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0303/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Bethel","otherGeospatial":"Locust Creek","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.75,43.75 ], [ -72.75,43.875 ], [ -72.625,43.875 ], [ -72.625,43.75 ], [ -72.75,43.75 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a6062","contributors":{"authors":[{"text":"Ivanoff, Michael A.","contributorId":27105,"corporation":false,"usgs":true,"family":"Ivanoff","given":"Michael","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":240283,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"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":240282,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49800,"text":"ofr96245 - 1996 - Level II scour analysis for Bridge 29 (BRIDTH00360029) on Town Highway 36, crossing North Branch Ottauquechee River, Bridgewater, Vermont","interactions":[],"lastModifiedDate":"2013-12-11T10:32:58","indexId":"ofr96245","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1996","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":"96-245","title":"Level II scour analysis for Bridge 29 (BRIDTH00360029) on Town Highway 36, crossing North Branch Ottauquechee River, Bridgewater, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nBRIDTH00360029 on town highway 36 crossing the North Branch Ottauquechee River, \nBridgewater, 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). A Level I study is included in Appendix E of this report. A Level I \nstudy provides a qualitative geomorphic characterization of the study site. Information on \nthe bridge available from VTAOT files was compiled prior to conducting Level I and Level \nII analyses and can be found in Appendix D.
\nThe site is in the Green Mountain physiographic division of central Vermont in the town of \nBridgewater. The 27.1-mi2\n drainage area is a predominantly rural basin. In the vicinity of \nthe study site, the left and right banks are covered by pasture and (or) fields with the \nimmediate stream banks covered by woody vegetation. The left bank of North Branch \nOttauquechee River is adjacent to Bridgewater town highway 001.
\nIn the study area, the North Branch Ottauquechee River has a sinuous channel with a slope \nof approximately 0.008 ft/ft, an average channel top width of 73 ft and an average bank \nheight of 6 ft. The predominant channel bed materials are gravel and cobble with a median \ngrain size (D50) of 61.0 mm (0.200 ft). The geomorphic assessment at the time of the Level \nI and Level II site visit on October 26, 1994, indicated that the reach was stable.
\nThe town highway 36 crossing of the North Branch Ottauquechee Riveris a 46-ft-long, \none-lane bridge consisting of one 43-foot steel-beam span (Vermont Agency of \nTransportation, written communication, August 25, 1994). The bridge is supported by \nvertical, concrete abutments with wingwalls. Type-2 (less than 36 inches) stone fill protects \nthe upstream and downstream wingwalls. Sparse type-2 stone fill was also observed along \nthe right abutment. The channel approach to the bridge is not skewed, however, the \nmeasured opening skew-to-roadway is five degrees. Additional details describing \nconditions 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 \nin Hydraulic Engineering Circular 18 (Richardson and others, 1993). 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 1.4 to 2.8 ft. The worst-case \ncontraction scour occurred at the incipient overtopping discharge, which was less than the \n100-year discharge. Abutment scour ranged from 7.3 to 13.2 ft. The worst-case abutment \nscour occurred at the 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 cross-section 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, 1993, p. 48). Many factors, \nincluding historical performance during flood events, the geomorphic assessment, scour \nprotection measures, and the results of the hydraulic analyses, must be considered to \nproperly assess the validity of abutment scour results. Therefore, scour depths adopted by \nVTAOT may differ from the computed values documented herein, based on the \nconsideration of additional contributing factors and experienced engineering judgement.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr96245","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Olson, S.A., and Ivanoff, M.A., 1996, Level II scour analysis for Bridge 29 (BRIDTH00360029) on Town Highway 36, crossing North Branch Ottauquechee River, Bridgewater, Vermont: U.S. Geological Survey Open-File Report 96-245, iv, 30 p., https://doi.org/10.3133/ofr96245.","productDescription":"iv, 30 p.","numberOfPages":"35","costCenters":[],"links":[{"id":178512,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96245.GIF"},{"id":279381,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0245/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Bridgewater","otherGeospatial":"North Branch Ottauquechee 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":"4f4e4b19e4b07f02db6a7f5c","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":240280,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Ivanoff, Michael A.","contributorId":27105,"corporation":false,"usgs":true,"family":"Ivanoff","given":"Michael","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":240281,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49798,"text":"ofr96243 - 1996 - Level II scour analysis for Bridge 42 (BRIDTH00040042) on Town Highway 04, crossing Dailey Hollow Brook, Bridgewater, Vermont","interactions":[],"lastModifiedDate":"2013-12-11T10:51:40","indexId":"ofr96243","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1996","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":"96-243","title":"Level II scour analysis for Bridge 42 (BRIDTH00040042) on Town Highway 04, crossing Dailey Hollow Brook, Bridgewater, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nBRIDTH00040042 on town highway 4 crossing Dailey Hollow Brook, Bridgewater, \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). A Level I study is included in Appendix E of this report. A Level I study provides \na qualitative geomorphic characterization of the study site. Information on the bridge \navailable from VTAOT files was compiled prior to conducting Level I and Level II \nanalyses and can be found in Appendix D.
\nThe site is in the Green Mountain physiographic division of central Vermont in the town of \nBridgewater. The 2.20-mi2\n drainage area is in a predominantly rural and forested basin. In \nthe vicinity of the study site, the overbanks are covered by shrubs and trees except for the \nupstream right overbank where there is a house. Dailey Hollow Brook enters Dailey Hollow \nBranch at the downstream face of the bridge.
\nIn the study area, Dailey Hollow Brook has an incised, sinuous channel with a slope of \napproximately 0.035 ft/ft. The channel top width and channel depth upstream of the bridge \nis 19 ft and 3 ft, respectively. Downstream of the bridge and the confluence the channel top \nwidth and channel depth is 39 ft and 2 ft respectively. The predominant channel bed \nmaterial is cobble and gravel (D50 is 64.7 mm or 0.212 ft). The geomorphic assessment at \nthe time of the Level I and Level II site visit on November 1, 1994, indicated that the reach \nwas stable.
\nThe town highway 4 crossing of Dailey Hollow Brook is a 25-ft-long, one-lane bridge \nconsisting of one 23-foot concrete span (Vermont Agency of Transportation, written \ncommunication, August 25, 1994). The bridge is supported by vertical, concrete abutments \nwith wingwalls. Type-2 stone fill (less than 36 inches) exists along all four wingwalls, the \ndownstream right road approach, and the channel banks in the immediate vicinity of the \nbridge. The channel is skewed approximately 20 degrees to the opening; the opening-skewto-roadway is also 20 degrees. 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, 1993). 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 modelled flows was 0.0 ft. Abutment scour ranged from 3.9 to 5.4 ft. \nwith the worst-case abutment scour occurring 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, 1993, p. 48). Many factors, \nincluding historical performance during flood events, the geomorphic assessment, scour \nprotection measures, and the results of the hydraulic analyses, must be considered to \nproperly assess the validity of abutment scour results. Therefore, scour depths adopted by \nVTAOT may differ from the computed values documented herein, based on the \nconsideration of additional contributing factors and experienced engineering judgement.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr96243","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Olson, S.A., and Weber, M.A., 1996, Level II scour analysis for Bridge 42 (BRIDTH00040042) on Town Highway 04, crossing Dailey Hollow Brook, Bridgewater, Vermont: U.S. Geological Survey Open-File Report 96-243, iv, 28 p., https://doi.org/10.3133/ofr96243.","productDescription":"iv, 28 p.","numberOfPages":"33","costCenters":[],"links":[{"id":179256,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96243.GIF"},{"id":279383,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0243/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Bridgewater","otherGeospatial":"Dailey Hollow Brook","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":"4f4e4b17e4b07f02db6a6179","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":240277,"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":240278,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49795,"text":"ofr96240 - 1996 - Level II scour analysis for Bridge 51 (RANDTH00SC0051) on School Street, crossing Thayer Brook, Randolph, Vermont","interactions":[],"lastModifiedDate":"2013-12-11T11:14:03","indexId":"ofr96240","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1996","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":"96-240","title":"Level II scour analysis for Bridge 51 (RANDTH00SC0051) on School Street, crossing Thayer Brook, Randolph, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nRANDTH00SC0051 on School Street crossing Thayer Brook, Randolph, 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). A Level \nI study is included in Appendix E of this report. A Level I study provides a qualitative \ngeomorphic characterization of the study site. Information on the bridge available from \nVTAOT files was compiled prior to conducting Level I and Level II analyses and can be \nfound in Appendix D.
\nThe site is in the Green Mountain physiographic division of central Vermont in the town of \nRandolph. The 5.30-mi2\n drainage area is a predominantly rural basin. In the vicinity of the \nstudy site, the left and right banks are forested with residences on the left overbanks.
\nIn the study area, Thayer Brook has a sinuous channel with a slope of approximately 0.03 ft/\nft, an average channel top width of 36 ft and an average channel depth of 3 ft. The \npredominant channel bed materials are gravel and cobble (D50 is 58.2 mm or 0.191 ft). The \ngeomorphic assessment at the time of the Level I site visits on August 4, 1994 and \nDecember 8, 1994, indicated that the reach was stable.
\nThe School Street crossing of Thayer Brook is a 39-ft-long, two-lane bridge consisting of \none 35-foot concrete span (Vermont Agency of Transportation, written commun., August 2, \n1994). The bridge is supported by vertical, concrete abutments with wingwalls. Type-2 \nstone fill (less than 36 inches diameter) along the downstream left bank was the only \nexisting protection. The approach channel is skewed approximately 45 degrees to the bridge \nface; the opening-skew-to-roadway is also 45 degrees. Additional details describing \nconditions at the site are included in the Level II Summary, Appendix D, and Appendix E.
\nScour depths and rock rip-rap sizes were computed using the general guidelines described \nin Hydraulic Engineering Circular 18 (Richardson and others, 1993). 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 1.0 to 2.2 ft. with the worst-case \nscenario occurring at the 500-year discharge. Abutment scour ranged from 6.2 to 12.0 ft. \nThe worst-case abutment scour also 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, 1993, p. 48). Many factors, \nincluding historical performance during flood events, the geomorphic assessment, scour \nprotection measures, and the results of the hydraulic analyses, must be considered to \nproperly assess the validity of abutment scour results. Therefore, scour depths adopted by \nVTAOT may differ from the computed values documented herein, based on the \nconsideration of additional contributing factors and experienced engineering judgement.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr96240","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Olson, S.A., 1996, Level II scour analysis for Bridge 51 (RANDTH00SC0051) on School Street, crossing Thayer Brook, Randolph, Vermont: U.S. Geological Survey Open-File Report 96-240, iv, 28 p., https://doi.org/10.3133/ofr96240.","productDescription":"iv, 28 p.","numberOfPages":"33","costCenters":[],"links":[{"id":179183,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96240.GIF"},{"id":279388,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0240/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Randolph","otherGeospatial":"Thayer Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.75,43.875 ], [ -72.75,44.0 ], [ -72.625,44.0 ], [ -72.625,43.875 ], [ -72.75,43.875 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a5b7a","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":240272,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":49794,"text":"ofr96239 - 1996 - Level II scour analysis for Bridge 35 (BETHTH00190035) on Town Highway 19, crossing Gilead Brook, Bethel, Vermont","interactions":[],"lastModifiedDate":"2013-12-11T11:20:02","indexId":"ofr96239","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1996","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":"96-239","title":"Level II scour analysis for Bridge 35 (BETHTH00190035) on Town Highway 19, crossing Gilead Brook, Bethel, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nBETHTH00190035 on town highway 19 crossing Gilead Brook, Bethel, 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). A Level \nI study is included in Appendix E of this report. A Level I study provides a qualitative \ngeomorphic characterization of the study site. Information on the bridge available from \nVTAOT files was compiled prior to conducting Level I and Level II analyses and can be \nfound in Appendix D.
\nThe site is in the Green Mountain physiographic province of central Vermont in the town of \nBethel. The 6.40-mi2\n drainage area is predominantly rural and forested. In the vicinity of \nthe study site, the immediate banks have woody vegetation coverage with pasture beyond.
\nIn the study area, Gilead Brook is an incised, sinuous channel with a slope of approximately \n0.015 ft/ft, an average channel top width of 31 ft and an average channel depth of 2.5 ft. The \npredominant channel bed material is gravel and cobble (D50 is 62.5 mm or 0.205 ft). The \ngeomorphic assessment at the time of the Level I and Level II site visit on October 20, \n1994, indicated that the reach was stable.
\nThe town highway 19 crossing of Gilead Brook is a 30-ft-long, one-lane bridge consisting \nof one 24-foot steel-beam span with timber deck (Vermont Agency of Transportation, \nwritten commun., August 24, 1994). The bridge is supported by vertical, concrete\nabutments with wingwalls. The channel is skewed approximately 5 degrees to the opening \nwhile the opening-skew-to-roadway is 10 degrees.
\nThe scour protection measures at the site included type-1 stone fill (less than 12 inches \ndiameter) at the downstream wingwalls, left abutment, and upstream right road \nembankment; type-2 stone fill (less than 36 inches diameter) is at the upstream right \nwingwall. Additional details describing conditions at the site are included in the Level II \nSummary 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, 1993). 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 0.1 to 2.1 ft. with the worst-case \nscenario occurring at the 500-year discharge. Abutment scour ranged from 3.9 to 9.5 ft. The \nworst-case abutment scour also occurred at the 500-year discharge. Additional information \non scour 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, 1993, p. 48). Many factors, \nincluding historical performance during flood events, the geomorphic assessment, scour \nprotection measures, and the results of the hydraulic analyses, must be considered to \nproperly assess the validity of abutment scour results. Therefore, scour depths adopted by \nVTAOT may differ from the computed values documented herein, based on the \nconsideration of additional contributing factors and experienced engineering judgement.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr96239","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Olson, S.A., and Song, D.L., 1996, Level II scour analysis for Bridge 35 (BETHTH00190035) on Town Highway 19, crossing Gilead Brook, Bethel, Vermont: U.S. Geological Survey Open-File Report 96-239, iv, 30 p., https://doi.org/10.3133/ofr96239.","productDescription":"iv, 30 p.","numberOfPages":"35","costCenters":[],"links":[{"id":179182,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96239.GIF"},{"id":279389,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0239/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Bethel","otherGeospatial":"Gilead Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.75,43.875 ], [ -72.75,44.0 ], [ -72.625,44.0 ], [ -72.625,43.875 ], [ -72.75,43.875 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a6473","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":240270,"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":240271,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49793,"text":"ofr96237 - 1996 - Level II scour analysis for Bridge 3 (BRIDTH000100003) on Town Highway 1, crossing Dailey Hollow Branch, Bridgewater, Vermont","interactions":[],"lastModifiedDate":"2013-12-11T11:34:45","indexId":"ofr96237","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1996","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":"96-237","title":"Level II scour analysis for Bridge 3 (BRIDTH000100003) on Town Highway 1, crossing Dailey Hollow Branch, Bridgewater, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nBRIDTH00010003 on town highway 1 crossing Dailey Hollow Branch, Bridgewater, \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). A Level I study is included in Appendix E of this report. A Level I study provides \na qualitative geomorphic characterization of the study site. Information on the bridge \navailable from VTAOT files was compiled prior to conducting Level I and Level II \nanalyses and can be found in Appendix D.
\nThe site is in the Green Mountain physiographic division of central Vermont in the town of \nBridgewater. The 9.88-mi2\n drainage area is in a predominantly rural, forested basin. In the \nvicinity of the study site, the immediate channel banks have moderate tree cover and shrubs \nwith residential properties on the overbank.
\nIn the study area, Dailey Hollow Branch has an incised, sinuous channel with a slope of \napproximately 0.009 ft/ft, an average channel top width of 46 ft and an average channel \ndepth of 4 ft. The predominant channel bed materials are gravel and cobble with a median \ngrain size (D50) of 89.7 mm (0.294 ft). The geomorphic assessment at the time of the Level \nI and Level II site visit on October 27, 1994, indicated that the reach was vertically \ndegrading.
\nThe town highway 1 crossing of Dailey Hollow Branch is a 45-ft-long, two-lane bridge \nconsisting of one 42-foot steel-beam span (Vermont Agency of Transportation, written \ncommunication, August 24, 1994). The bridge is supported by vertical, concrete abutments \nwith wingwalls. Type-2 stone fill (less than 36 inches diameter) protects the downstream \nright and left wingwall. Type-3 stone fill (less than 48 inches diameter) exists on the \ndownstream right bank. The left abutment is undermined by up to one foot. Horizontal \nprobing under the abutment resulted in penetration up to 6 feet.
\nThe bridge is misaligned with the channel. Higher discharges may directly impact the left \nwingwall. The channel is skewed approximately 20 degrees to the bridge; the opening-skew-to-roadway is also 20 degrees. Additional details describing conditions at the site are \nincluded in the Level II Summary and Appendices D \nand E.
\nScour depths and rock rip-rap sizes were computed using the general guidelines described \nin Hydraulic Engineering Circular 18 (Richardson and others, 1993).\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 0.6 ft to 1.3 ft and the worst-case \ncontraction scour occurred at the 500-year discharge. Abutment scour ranged from 6.7 ft to \n12.2 ft 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”. \nScour elevations, based on the calculated depths are presented in tables 1 and 2; a graph of \nthe scour elevations is presented in figure 8 Scour depths were calculated assuming an \ninfinite depth of erosive material and a homogeneous particle-size distribution.
\nFor all scour presented in this report, “the scour depths adopted [by VTAOT] may differ \nfrom the equation values based on engineering judgement” (Richardson and others, 1993, p. \n21, 27). It is generally accepted that the Froehlich equation (abutment scour) gives \n“excessively conservative estimates of scour depths” (Richardson and others, 1993, p. 48). \nMany factors, including historical performance during flood events, the geomorphic \nassessment, and the results of the hydraulic analyses, must be considered to properly assess \nthe validity of abutment scour results.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr96237","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Olson, S.A., and Song, D.L., 1996, Level II scour analysis for Bridge 3 (BRIDTH000100003) on Town Highway 1, crossing Dailey Hollow Branch, Bridgewater, Vermont: U.S. Geological Survey Open-File Report 96-237, iv, 27 p., https://doi.org/10.3133/ofr96237.","productDescription":"iv, 27 p.","numberOfPages":"32","costCenters":[],"links":[{"id":179181,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96237.GIF"},{"id":279390,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0237/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Bridgewater","otherGeospatial":"Dailey Hollow Branch","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":"4f4e4b19e4b07f02db6a7f05","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":240268,"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":240269,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49792,"text":"ofr96236 - 1996 - Level II scour analysis for Bridge 34 (RANDTH00660034) on Town Highway 66, crossing Second Branch White River, Randolph, Vermont","interactions":[],"lastModifiedDate":"2013-12-11T11:46:46","indexId":"ofr96236","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1996","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":"96-236","title":"Level II scour analysis for Bridge 34 (RANDTH00660034) on Town Highway 66, crossing Second Branch White River, Randolph, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nRANDTH00660034 on town highway 66 crossing the Second Branch White River, \nRandolph, 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). A Level I study is included in Appendix E of this report. A Level I \nstudy provides a qualitative geomorphic characterization of the study site. Information on \nthe bridge available from VTAOT files was compiled prior to conducting Level I and Level \nII analyses and can be found in Appendix D.
\nThe site is in the Green Mountain physiographic division of central Vermont in the town of \nRandolph. The 51.3-mi2\n drainage area is in a predominantly rural basin. In the vicinity of \nthe study site, the left and right banks are covered by fields with some brush on the \nupstream left and downstream right banks and with row crops on the downstream left \noverbank.
\nIn the study area, the Second Branch White River has a sinuous channel with a slope of \napproximately 0.002 ft/ft, an average channel top width of 60 ft and an average channel \ndepth of 7 ft. The predominant channel bed material is sand (D50 is 1.34 mm or 0.0044 ft). \nThe geomorphic assessment at the time of the Level I and Level II site visit on August 11, \n1994, indicated that the reach was laterally unstable. Channel scour is evident along the left \nhalf of the channel from about 30 feet upstream to about 20 feet downstream of the bridge. \nThere is a cut bank with block failures along the left bank upstream of the bridge further \nindicating instability of the stream reach.
\nThe town highway 66 crossing of the Second Branch White Riveris a 57-ft-long, one-lane\ncovered bridge consisting of one 45-foot span (Vermont Agency of Transportation, written \ncommunication, July 29, 1994). The bridge is supported by vertical, concrete abutments \nwith one wingwall on the upstream left side. The base of the left abutment was protected by \ntype-1 stone fill (less than 12 inches diameter). The channel is skewed approximately 40 \ndegrees to the opening while the opening-skew-to-roadway is 45 degrees. Additional details \ndescribing conditions at the site are included in the Level II Summary and Appendices D \nand E.
\nScour depths and rock rip-rap sizes were computed using the general guidelines described \nin Hydraulic Engineering Circular 18 (Richardson and others, 1993).\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 6.3 ft to 7.8 ft and the worst-case \ncontraction scour occurred at the 100-year discharge. Abutment scour ranged from 7.9 ft to \n20.3 ft 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”. \nScour elevations, based on the calculated depths are presented in tables 1 and 2; a graph of \nthe scour elevations is presented in figure 8 Scour depths were calculated assuming an \ninfinite depth of erosive material and a homogeneous particle-size distribution.
\nFor all scour presented in this report, “the scour depths adopted [by VTAOT] may differ \nfrom the equation values based on engineering judgement” (Richardson and others, 1993, p. \n21, 27). It is generally accepted that the Froehlich equation (abutment scour) gives \n“excessively conservative estimates of scour depths” (Richardson and others, 1993, p. 48). \nMany factors, including historical performance during flood events, the geomorphic \nassessment, and the results of the hydraulic analyses, must be considered to properly assess \nthe validity of abutment scour results.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr96236","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Olson, S.A., and Ayotte, J., 1996, Level II scour analysis for Bridge 34 (RANDTH00660034) on Town Highway 66, crossing Second Branch White River, Randolph, Vermont: U.S. Geological Survey Open-File Report 96-236, iv, 30 p., https://doi.org/10.3133/ofr96236.","productDescription":"iv, 30 p.","numberOfPages":"35","costCenters":[],"links":[{"id":179180,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96236.GIF"},{"id":279391,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0236/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Randolph","otherGeospatial":"Second Branch White River","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.625,43.875 ], [ -72.625,44.0 ], [ -72.5,44.0 ], [ -72.5,43.875 ], [ -72.625,43.875 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a64ed","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":240267,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Ayotte, Joseph D. jayotte@usgs.gov","contributorId":1802,"corporation":false,"usgs":true,"family":"Ayotte","given":"Joseph D.","email":"jayotte@usgs.gov","affiliations":[{"id":466,"text":"New England Water Science Center","active":true,"usgs":true}],"preferred":false,"id":240266,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49791,"text":"ofr96234 - 1996 - Level II scour analysis for Bridge 39 (RANDTH00730039) on Town Highway 73, crossing the Second Branch White River, Randolph, Vermont","interactions":[],"lastModifiedDate":"2013-12-11T12:43:20","indexId":"ofr96234","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1996","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":"96-234","title":"Level II scour analysis for Bridge 39 (RANDTH00730039) on Town Highway 73, crossing the Second Branch White River, Randolph, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nRANDTH00730039 on town highway 73 crossing the Second Branch White River, \nRandolph, 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). A Level I study is included in Appendix E of this report. A Level I \nstudy provides a qualitative geomorphic characterization of the study site. Information on \nthe bridge available from VTAOT files was compiled prior to conducting Level I and Level \nII analyses and can be found in Appendix D.
\nThe site is in the Green Mountain physiographic province of central Vermont in the town of \nRandolph. The 53.7-mi2\n drainage area is in a predominantly rural basin. In the vicinity of \nthe study site, the overbanks are covered by pasture except for the upstream right bank \nwhich is covered by brush.
\nIn the study area, the Second Branch White River has a meandering channel with a slope of \napproximately 0.001 ft/ft, an average channel top width of 44 ft and an average channel \ndepth of 6 ft. The predominant channel bed material is sand with median grain size (D50) of \n0.884 mm (0.0029 ft). The geomorphic assessment at the time of the Level I and Level II \nsite visit on August 12, 1994, indicated that the reach was laterally unstable. This is because \nof severe cut-banks both upstream and downstream where mass wasting and block failure \nof bank material is evident. Furthermore, minimal erosion protection is provided by bank \nvegetation since woody vegetation cover is sparse.
\nThe town highway 73 crossing of the Second Branch White Riveris a 42-ft-long, one-lane\nbridge consisting of one 40-foot span (Vermont Agency of Transportation, written \ncommunication, August 2, 1994). The bridge is supported by vertical, concrete abutments \nwith wingwalls. The ends of the upstream left wingwall and the downstream right wingwall \nare protected by stone fill. However, this stone fill is slumping according to the Level I field \ninspection. The channel is skewed approximately 30 degrees to the opening while the \nopening-skew-to-roadway is 0 degrees. Additional details describing conditions at the site \nare 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 \nin Hydraulic Engineering Circular 18 (Richardson and others, 1993).\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 1.9 ft to 4.6 ft and the worst-case \ncontraction scour occurred at the incipient overtopping discharge. Abutment scour ranged \nfrom 4.0 ft to 22.5 ft and the worst-case abutment scour occurred at the 500-year discharge. \nScour depths and depths to armoring are summarized on p. 14 in the section titled “Scour \nResults”. Scour elevations, based on the calculated depths are presented in tables 1 and 2; \na graph of the scour elevations is presented in figure 8 Scour depths were calculated \nassuming an infinite depth of erosive material and a homogeneous particle-size distribution.
\nFor all scour presented in this report, “the scour depths adopted [by VTAOT] may differ \nfrom the equation values based on engineering judgement” (Richardson and others, 1993, p. \n21, 27). It is generally accepted that the Froehlich equation (abutment scour) gives \n“excessively conservative estimates of scour depths” (Richardson and others, 1993, p. 48). \nMany factors, including historical performance during flood events, the geomorphic \nassessment, and the results of the hydraulic analyses, must be considered to properly assess \nthe validity of abutment scour results.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr96234","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Song, D.L., and Ivanoff, M.A., 1996, Level II scour analysis for Bridge 39 (RANDTH00730039) on Town Highway 73, crossing the Second Branch White River, Randolph, Vermont: U.S. Geological Survey Open-File Report 96-234, iv, 30 p., https://doi.org/10.3133/ofr96234.","productDescription":"iv, 30 p.","numberOfPages":"35","costCenters":[],"links":[{"id":179179,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96234.GIF"},{"id":279392,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0234/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Randolph","otherGeospatial":"Second Branch White River","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.625,43.875 ], [ -72.625,44.0 ], [ -72.5,44.0 ], [ -72.5,43.875 ], [ -72.625,43.875 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a62b0","contributors":{"authors":[{"text":"Song, Donald L.","contributorId":107335,"corporation":false,"usgs":true,"family":"Song","given":"Donald","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":240265,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Ivanoff, Michael A.","contributorId":27105,"corporation":false,"usgs":true,"family":"Ivanoff","given":"Michael","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":240264,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49789,"text":"ofr96231 - 1996 - Level II scour analysis for Bridge 25 (HARDTH00420025) on Town Highway 42, crossing Lamoille River, Hardwick, Vermont","interactions":[],"lastModifiedDate":"2013-12-11T12:59:53","indexId":"ofr96231","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1996","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":"96-231","title":"Level II scour analysis for Bridge 25 (HARDTH00420025) on Town Highway 42, crossing Lamoille River, Hardwick, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nHARDTH00420025 on town highway 42 crossing the Lamoille River, Hardwick, 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 study is included in Appendix E of this report. A Level I study provides \na qualitative geomorphic characterization of the study site. Information on the bridge \navailable from VTAOT files was compiled prior to conducting Level I and Level II \nanalyses and can be found in Appendix D.
\nThe site is in the Green Mountain physiographic division of north-central Vermont in the \ntown of Hardwick. The 119-mi2\n drainage area is in a predominantly rural basin. In the \nvicinity of the study site, the left banks are covered by pasture and (or) fields. The right \nbank of Lamoille River is adjacent to Vermont Route 15 near the north edge of the Lamoille \nRiver valley.
\nIn the study area, the Lamoille River has a sinuous channel with a slope of approximately \n0.0004 ft/ft, an average channel top width of 89.0 ft and an average channel depth of 8.0 ft. \nThe predominant channel bed material is sand and gravel (D50 is 22.4 mm or 0.0733 ft). In \ngeneral, the banks have sparse or no woody vegetative cover and the reach was noted to be \nlaterally unstable at the time of the Level I site visit on July 25, 1995. The Level II work \nwas completed on 07/27/95 and the site was revisited on August 16, 1995, just after the \nAugust 5-6, 1995 flood on the Lamoille River. Findings from this follow-up visit are \npresented in Appendix G.
\nThe town highway 42 crossing of the Lamoille Riveris a 62-ft-long, two-lane bridge \nconsisting of one 60-foot steel- beam span with a concrete deck, supported by vertical \nabutments with wingwalls on upstream and downstream sides (Vermont Agency of \nTransportation, written commun., August 24, 1994). The bridge is supported by vertical \nabutments with wingwalls on upstream and downstream sides. The channel is not skewed to \nthe opening and the opening-skew-to-roadway is 0 degrees.
\nA scour hole 3.0 ft deeper than the mean thalweg depth was observed 5 feet upstream from \nthe bridge face at mid-channel during the Level I assessment. Additional details describing \nconditions 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 \nin Hydraulic Engineering Circular 18 (Richardson and others, 1993).\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 was 0.0 ft. Abutment scour ranged from 6.5 ft to \n15.6 ft 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”. \nScour elevations, based on the calculated depths are presented in tables 1 and 2; a graph of \nthe scour elevations is presented in figure 8 Scour depths were calculated assuming an \ninfinite depth of erosive material and a homogeneous particle-size distribution.
\nFor all scour presented in this report, “the scour depths adopted [by VTAOT] may differ \nfrom the equation values based on engineering judgement” (Richardson and others, 1993, p. \n21, 27). It is generally accepted that the Froehlich equation (abutment scour) gives \n“excessively conservative estimates of scour depths” (Richardson and others, 1993, p. 48). \nMany factors, including historical performance during flood events, the geomorphic \nassessment, and the results of the hydraulic analyses, must be considered to properly assess \nthe validity of abutment scour results.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr96231","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Ayotte, J., 1996, Level II scour analysis for Bridge 25 (HARDTH00420025) on Town Highway 42, crossing Lamoille River, Hardwick, Vermont: U.S. Geological Survey Open-File Report 96-231, iv, 31 p., https://doi.org/10.3133/ofr96231.","productDescription":"iv, 31 p.","numberOfPages":"36","costCenters":[],"links":[{"id":179107,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96231.GIF"},{"id":279394,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0231/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Hardwick","otherGeospatial":"Lamoille River","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.5,44.5 ], [ -72.5,44.625 ], [ -72.375,44.625 ], [ -72.375,44.5 ], [ -72.5,44.5 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b1ae4b07f02db6a8043","contributors":{"authors":[{"text":"Ayotte, Joseph D. jayotte@usgs.gov","contributorId":1802,"corporation":false,"usgs":true,"family":"Ayotte","given":"Joseph D.","email":"jayotte@usgs.gov","affiliations":[{"id":466,"text":"New England Water Science Center","active":true,"usgs":true}],"preferred":false,"id":240261,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":49788,"text":"ofr96198 - 1996 - Level II scour analysis for Bridge 40 (BETHTH00230040) on Town Highway 23, crossing Gilead Brook, Bethel, Vermont","interactions":[],"lastModifiedDate":"2013-12-06T14:00:07","indexId":"ofr96198","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1996","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":"96-198","title":"Level II scour analysis for Bridge 40 (BETHTH00230040) on Town Highway 23, crossing Gilead Brook, Bethel, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nBETHTH00230040 on town highway 23 crossing Gilead Brook, Bethel, 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). A Level \nI study is included in Appendix E of this report. A Level I study provides a qualitative \ngeomorphic characterization of the study site. Information on the bridge, gleaned from \nVTAOT files, was compiled prior to conducting the Level I and Level II analyses and can \nbe found in Appendix D.\nThe site is in the Green Mountain physiographic province of central Vermont in the town of \nBethel. The 10.2-mi2 drainage area is in a predominantly rural and forested basin. In the \nvicinity of the study site, the banks have moderately dense woody vegetation coverage.\nIn the study area, the Gilead Brook has an incised, sinuous channel downstream of the site \nand a meandering channel upstream, with narrow flood plains and a slope of approximately \n0.015 ft/ft, an average channel top width of 47.0 ft and an average channel depth of 2.75 ft. \nThe predominant channel bed materials are gravel and cobble (D50 is 94.8 mm or 0.311 ft). \nThe geomorphic assessment at the time of the Level I and Level II site visit on October 14, \n1994, indicated that the reach was laterally unstable.\nThe town highway 23 crossing of Gilead Brook is a 37-ft-long, one-lane bridge consisting \nof one 34-foot span steel-stringer type superstructure (Vermont Agency of Transportation, \nwritten commun., August 24, 1994). The bridge is supported by vertical, concrete \nabutments with concrete wingwalls. The channel is skewed 25 degrees to the opening and \nthe opening-skew-to-roadway is zero degrees. \nA scour hole 1.0 ft deeper than the mean thalweg depth was observed along the downstream \nright wingwall during the Level I assessment. The scour protection measures at the site \nwere type-2 stone fill (less than 36 inches diameter) on the upstream and downstream right \nroadway embankments, at the extreme upstream and downstream ends of the upstream and \ndownstream right wingwalls, and along the entire base length of 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 rock rip-rap sizes were computed using the general guidelines described \nin Hydraulic Engineering Circular 18 (Richardson and others, 1993). Scour depths were \ncalculated assuming an infinite depth of erosive material and a homogeneous particle-size \ndistribution. The scour analysis results are presented in tables 1 and 2 and a graph of the \nscour depths is presented in figure 8.","language":"English","publisher":"U.S. Geological Survey","doi":"10.3133/ofr96198","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Boehmler, E.M., 1996, Level II scour analysis for Bridge 40 (BETHTH00230040) on Town Highway 23, crossing Gilead Brook, Bethel, Vermont: U.S. Geological Survey Open-File Report 96-198, iv, 31 p., https://doi.org/10.3133/ofr96198.","productDescription":"iv, 31 p.","numberOfPages":"36","costCenters":[],"links":[{"id":179106,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96198.png"},{"id":279403,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0198/report.pdf"}],"country":"United States","state":"Vermont","city":"Bethel","otherGeospatial":"Gilead Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.765979,43.790521 ], [ -72.765979,43.910383 ], [ -72.574443,43.910383 ], [ -72.574443,43.790521 ], [ -72.765979,43.790521 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a61a4","contributors":{"authors":[{"text":"Boehmler, Erick M.","contributorId":96303,"corporation":false,"usgs":true,"family":"Boehmler","given":"Erick","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":240260,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":49787,"text":"ofr96197 - 1996 - Level II scour analysis for Bridge 23 (WODSTH00180023) on Town Highway 18, crossing North Bridgewater Brook, Woodstock, Vermont","interactions":[],"lastModifiedDate":"2013-12-06T14:15:30","indexId":"ofr96197","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1996","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":"96-197","title":"Level II scour analysis for Bridge 23 (WODSTH00180023) on Town Highway 18, crossing North Bridgewater Brook, Woodstock, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nWODSTH00180023 on town highway 18 crossing North Bridgewater Brook, Woodstock, \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). A Level I study is included in Appendix E of this report. A Level I study provides \na qualitative geomorphic characterization of the study site. Information on the bridge, \navailable from VTAOT files, was compiled prior to conducting Level I and Level II \nanalyses and can be found in Appendix D.\nThe site is in the New England Upland physiographic division of east-central Vermont. The \n4.26-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the \nstudy site, the left and right banks are covered by moderate tree cover.\nIn the study area, North Bridgewater Brook has a sinuous channel with a slope of \napproximately 0.03 ft/ft, an average channel top width of 38 ft and an average channel \ndepth of 5 ft. The predominant channel bed materials are gravel and cobbles (D50 is 63.3 \nmm or 0.208 ft). The geomorphic assessment at the time of the Level I site visit on \nDecember 9, 1994 indicated that the reach was laterally unstable. Evidence of the instability \nincluded anabranching and extensive stone fill on channel bends.\nThe town highway 18 crossing of North Bridgewater Brook is a 25-ft-long, one-lane bridge \nconsisting of one 22-ft steel-beam span (Vermont Agency of Transportation, written \ncommun., August 3, 1994). The bridge is supported by vertical, concrete abutments with no \nwingwalls. Type-2 stone fill (less than 36 inches) was noted at the ends of the right \nabutment and type-1 stone fill (less than 12 inches) was noted at the ends of the left \nabutment. A stone wall of type-2 and -3 stone fill (less than 36 inches and 48 inches, \nrespectively), carefully placed, protects the upstream right channel bank extending from the \nbridge to more than 50 feet upstream. Although significant protection has been placed, both \nabutments are experiencing undermining. The channel is skewed approximately 15 degrees \nto the opening while the opening-skew-to-roadway is 5 degrees. Additional details \ndescribing conditions at the site are included in the Level II Summary and Appendices D\nand E.\nScour depths and rock rip-rap sizes were computed using the general guidelines described \nin Hydraulic Engineering Circular 18 (Richardson and others, 1993). Scour depths were \ncalculated assuming an infinite depth of erosive material and a homogeneous particle-size \ndistribution. The scour analysis results are presented in tables 1 and 2 and a graph of the \nscour depths is presented in figure 8.","language":"English","publisher":"U.S. Geological Survey","doi":"10.3133/ofr96197","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Olson, S.A., and Weber, M.A., 1996, Level II scour analysis for Bridge 23 (WODSTH00180023) on Town Highway 18, crossing North Bridgewater Brook, Woodstock, Vermont: U.S. Geological Survey Open-File Report 96-197, iv, 31 p., https://doi.org/10.3133/ofr96197.","productDescription":"iv, 31 p.","numberOfPages":"36","costCenters":[],"links":[{"id":178612,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96197.png"},{"id":279404,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0197/report.pdf"}],"country":"United States","state":"Vermont","city":"Woodstock","otherGeospatial":"North Bridgewater Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.637941,43.533341 ], [ -72.637941,43.661214 ], [ -72.46644,43.661214 ], [ -72.46644,43.533341 ], [ -72.637941,43.533341 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b1ae4b07f02db6a80d7","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":240258,"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":240259,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49786,"text":"ofr96196 - 1996 - Level II scour analysis for Bridge 31 (ALBATH00380031) on Town Highway 38, crossing the Black River, Albany, Vermont","interactions":[],"lastModifiedDate":"2013-12-06T14:55:18","indexId":"ofr96196","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1996","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":"96-196","title":"Level II scour analysis for Bridge 31 (ALBATH00380031) on Town Highway 38, crossing the Black River, Albany, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nALBATH00380031 on town highway 38 crossing the Black River, Albany, 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 study is included in Appendix E of this report. A Level I study provides \na qualitative geomorphic characterization of the study site. Information on the bridge, \ngleaned from VTAOT files, was compiled prior to conducting Level I and Level II analyses \nand can be found in Appendix D.\nThe site is in the New England Upland physiographic province of North-central Vermont in \nthe town of Albany. The 47.5-mi2 drainage area is in a rural, forested basin. In the vicinity \nof the study site, the immediate banks have mainly shrub and brush vegetation. The \noverbank areas are pasture, except for the upstream right bank which is forested.\nIn the study area, the Black River has a meandering channel with a slope of approximately \n0.0009 ft/ft, an average channel top width of 57 ft and an average channel depth of 3 ft. The \npredominant channel bed material is gravel (D50 is 35.4 mm or 0.116 ft). The geomorphic \nassessment at the time of the Level I and Level II site visit on October 5, 1994, indicated \nthat the reach was stable.\nThe town highway 38 crossing of the Black River is a 50-ft-long, one-lane bridge consisting \nof one 47-foot span concrete T-beam type superstructure (Vermont Agency of \nTransportation, written commun., August 3, 1994). The bridge is supported by vertical \nabutments with wingwalls. The left abutment is constructed of concrete while the right is \nmortared, granite stone blocks. The channel is skewed approximately 30 degrees to the \nopening while the opening-skew-to-roadway is 10 degrees. \nA scour hole, 1.5 ft deeper than the mean thalweg depth, was observed during the level I \nassessment along the left side of the channel under the bridge. The only scour protection \nmeasure at the site was type-3 stone fill (less than 48 inches diameter) along the left bank \nunder the bridge. Additional details describing conditions at the site are included in the \nLevel II Summary and Appendices D\nand E.\nScour depths and rock rip-rap sizes were computed using the general guidelines described \nin Hydraulic Engineering Circular 18 (Richardson and others, 1993). Scour depths were \ncalculated assuming an infinite depth of erosive material and a homogeneous particle-size \ndistribution. The scour analysis results are presented in tables 1 and 2 and a graph of the \nscour depths is presented in figure 8.","language":"English","publisher":"U.S. Geological Survey","doi":"10.3133/ofr96196","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Boehmler, E.M., 1996, Level II scour analysis for Bridge 31 (ALBATH00380031) on Town Highway 38, crossing the Black River, Albany, Vermont: U.S. Geological Survey Open-File Report 96-196, iv, 30 p., https://doi.org/10.3133/ofr96196.","productDescription":"iv, 30 p.","numberOfPages":"35","costCenters":[],"links":[{"id":178611,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96196.png"},{"id":279409,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0196/report.pdf"}],"country":"United States","state":"Vermont","city":"Albany","otherGeospatial":"Black River","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.423089,44.67299 ], [ -72.423089,44.794469 ], [ -72.253335,44.794469 ], [ -72.253335,44.67299 ], [ -72.423089,44.67299 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b19e4b07f02db6a7dc6","contributors":{"authors":[{"text":"Boehmler, Erick M.","contributorId":96303,"corporation":false,"usgs":true,"family":"Boehmler","given":"Erick","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":240257,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":49785,"text":"ofr96195 - 1996 - Level II scour analysis for Bridge 27 (BRIDTH00490027) on Town Highway 049, crossing Broad Brook, Bridgewater, Vermont","interactions":[],"lastModifiedDate":"2013-12-06T15:01:48","indexId":"ofr96195","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1996","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":"96-195","title":"Level II scour analysis for Bridge 27 (BRIDTH00490027) on Town Highway 049, crossing Broad Brook, Bridgewater, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nBRIDTH00490027 on town highway 49 crossing Broad Brook, Bridgewater, 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 study is included in Appendix E of this report. A Level I study provides \na qualitative geomorphic characterization of the study site. Information on the bridge \navailable from VTAOT files was compiled prior to conducting Level I and Level II \nanalyses and can be found in Appendix D.\nThe site is in the Green Mountain physiographic province of central Vermont in the town of \nBridgewater. The 13.9-mi2 drainage area is in a predominantly rural and forested basin. In \nthe vicinity of the study site, the left and right banks are pasture with moderate tree cover on \nthe immediate banks. Upstream of bridge 27, a gravel road runs parallel to the left bank.\nIn the study area, the Broad Brook has an incised channel with a slope of approximately \n0.007 ft/ft, an average channel top width of 54 ft and an average channel depth of 4 ft. The \npredominant channel bed materials are gravel and cobble with a D50 (median diameter) \nof \n77.9 mm or 0.256 ft. The geomorphic assessment at the time of the Level I and Level II site \nvisit on November 9, 1994, indicated that the reach was stable.\nThe town highway 49 crossing of the Broad Brook is a 32-ft-long, one-lane bridge \nconsisting of one 31-ft steel-beam span (Vermont Agency of Transportation, written \ncommun., August 24, 1994). The bridge is supported by vertical, concrete abutments with \nwingwalls. The left abutment is noted as settled due to previous undermining. Type-2 (less \nthan 3 ft diameter) stone fill protects the upstream left and right wingwalls, the downstream \nright wingwall, the right abutment, the upstream right road embankment, and the \ndownstream left and right road embankments. Type-3 (less than 4 ft diameter) stone fill \nprotects the downstream left wingwall, but it’s condition was reported as slumping. The \nchannel is skewed approximately 10 degrees to the opening; the opening-skew-to-roadway \nis also 10 degrees. 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, 1993). Scour depths were \ncalculated assuming an infinite depth of erosive material and a homogeneous particle-size \ndistribution. The scour analysis results are presented in tables 1 and 2 and a graph of the \nscour depths is presented in figure 8.","language":"English","publisher":"U.S. Geological Survey","doi":"10.3133/ofr96195","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Olson, S.A., 1996, Level II scour analysis for Bridge 27 (BRIDTH00490027) on Town Highway 049, crossing Broad Brook, Bridgewater, Vermont: U.S. Geological Survey Open-File Report 96-195, iv, 30 p., https://doi.org/10.3133/ofr96195.","productDescription":"iv, 30 p.","numberOfPages":"35","costCenters":[],"links":[{"id":178610,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96195.png"},{"id":279410,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0195/report.pdf"}],"country":"United States","state":"Vermont","city":"Bridgewater","otherGeospatial":"Broad Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.758005,43.558839 ], [ -72.758005,43.694051 ], [ -72.577733,43.694051 ], [ -72.577733,43.558839 ], [ -72.758005,43.558839 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b1ae4b07f02db6a7fcd","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":240256,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":49784,"text":"ofr96194 - 1996 - Level II scour analysis for Bridge 25 (ALBATH00250030) on Town Highway 25, crossing the Black River, Albany, Vermont","interactions":[],"lastModifiedDate":"2013-12-06T15:15:48","indexId":"ofr96194","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1996","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":"96-194","title":"Level II scour analysis for Bridge 25 (ALBATH00250030) on Town Highway 25, crossing the Black River, Albany, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nALBATH00250030 on town highway 25 crossing the Black River, Albany, 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 study is included in Appendix E of this report. A Level I study provides \na qualitative geomorphic characterization of the study site. Information on the bridge \navailable from VTAOT files were compiled prior to conducting Level I and Level II \nanalyses and can be found in Appendix D.\nThe site is in the New England Upland physiographic province of north-central Vermont in \nthe town of Albany. The 58.8-mi2 drainage area is in a rural, forested basin. In the vicinity \nof the study site, the banks have predominantly grass vegetation coverage with a few \nshrubs.\nIn the study area, the Black River has a non-incised, highly meandering channel with a \nslope of approximately 0.0005 ft/ft, an average channel top width of 56 ft and an average \nchannel depth of 4 ft. The predominant channel bed material is fine sand (D50 is 1.68 mm or \n0.00551 ft). The geomorphic assessment at the time of the Level I and Level II site visit on \nJune 5, 1995, indicated that the reach was laterally unstable.\nThe town highway 25 crossing of the Black River is a 42-ft-long, one-lane bridge consisting \nof one 40-foot span steel-beam superstructure with a timber deck (Vermont Agency of \nTransportation, written commun., August 3, 1994). The bridge is supported by vertical, \nconcrete abutments with wingwalls. The channel is not skewed to the opening and the \nopening-skew-to-roadway is zero degrees. \nA scour hole 0.5 ft deeper than the mean thalweg depth was observed along mid-channel \nfrom 40 feet upstream to about 10 feet under the bridge during the Level I assessment. The \nleft abutment is slightly undermined at the downstream end. The only scour protection \nmeasures at the site were sparse type-1 stone fill (less than 12 inches diameter) on the \nupstream right road embankment, along the left and right abutments, and along 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 rock rip-rap sizes were computed using the general guidelines described \nin Hydraulic Engineering Circular 18 (Richardson and others, 1993). Scour depths were \ncalculated assuming an infinite depth of erosive material and a homogeneous particle-size \ndistribution. The scour analysis results are presented in tables 1 and 2 and a graph of the \nscour depths is presented in figure 8.","language":"English","publisher":"U.S. Geological Survey","doi":"10.3133/ofr96194","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Boehmler, E.M., 1996, Level II scour analysis for Bridge 25 (ALBATH00250030) on Town Highway 25, crossing the Black River, Albany, Vermont: U.S. Geological Survey Open-File Report 96-194, iv, 30 p., https://doi.org/10.3133/ofr96194.","productDescription":"iv, 30 p.","numberOfPages":"35","costCenters":[],"links":[{"id":178609,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96194.png"},{"id":279411,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0194/report.pdf"}],"country":"United States","state":"Vermont","city":"Albany","otherGeospatial":"Black River","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.423089,44.67299 ], [ -72.423089,44.794469 ], [ -72.253335,44.794469 ], [ -72.253335,44.67299 ], [ -72.423089,44.67299 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b1ae4b07f02db6a8098","contributors":{"authors":[{"text":"Boehmler, Erick M.","contributorId":96303,"corporation":false,"usgs":true,"family":"Boehmler","given":"Erick","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":240255,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":49783,"text":"ofr96193 - 1996 - Level II scour analysis for Bridge 6 (IRASTH00050006) on Town Highway 5, crossing the Black River, Irasburg, Vermont","interactions":[],"lastModifiedDate":"2013-12-06T15:21:23","indexId":"ofr96193","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1996","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":"96-193","title":"Level II scour analysis for Bridge 6 (IRASTH00050006) on Town Highway 5, crossing the Black River, Irasburg, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nIRASTH00050006 on town highway 5 crossing the Black River, Irasburg, 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 study is included in Appendix E of this report. A Level I study provides \na qualitative geomorphic characterization of the study site. Information on the bridge \navailable from VTAOT files were compiled prior to conducting Level I and Level II \nanalyses and can be found in Appendix D.\nThe site is in the New England Upland physiographic province of north-central Vermont. \nThe 91.1-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of \nthe study site, the left and right banks are forested and a residence is located on the \ndownstream left overbank.\nIn the study area, the Black River has an incised, sinuous channel with a slope of \napproximately 0.05 ft/ft, an average channel top width of 116 ft and an average bank-full \nchannel depth of 2.8 ft. The predominant channel bed material is cobble (D50 is 240 mm or \n0.789 ft). The geomorphic assessment at the time of the Level I and Level II site visit on \nOctober 4, 1994, indicated that the reach was stable.\nThe town highway 5 crossing of the Black River is a 70-ft-long, two-lane bridge consisting \nof one 65-foot clear span (Vermont Agency of Transportation, written commun., August 2, \n1994). The bridge is supported by vertical, concrete abutments with wingwalls. There is \nalso a retaining wall along the upstream side of the road embankments. The channel is \nskewed approximately 20 degrees to the opening while the opening-skew-to-roadway is 15 \ndegrees.\nA scour hole 3.0 ft deeper than the mean thalweg depth was observed along the right \nabutment. The scour hole was 27 feet long, 15 feet wide, and was 2.5 feet below the \nabutment footing at the time of the Level I assessment. This right abutment had numerous \ncracks and had settled. Additional details describing conditions at the site are included in \nthe Level II Summary and Appendices D \nand E.\nScour depths and rock rip-rap sizes were computed using the general guidelines described \nin Hydraulic Engineering Circular 18 (Richardson and others, 1993). Scour depths were \ncalculated assuming an infinite depth of erosive material and a homogeneous particle-size \ndistribution. The scour analysis results are presented in tables 1 and 2 and a graph of the \nscour depths is presented in figure 8.","language":"English","publisher":"U.S. Geological Survey","doi":"10.3133/ofr96193","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Olson, S.A., 1996, Level II scour analysis for Bridge 6 (IRASTH00050006) on Town Highway 5, crossing the Black River, Irasburg, Vermont: U.S. Geological Survey Open-File Report 96-193, iv, 28 p., https://doi.org/10.3133/ofr96193.","productDescription":"iv, 28 p.","numberOfPages":"33","costCenters":[],"links":[{"id":178510,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96193.png"},{"id":279413,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0193/report.pdf"}],"country":"United States","state":"Vermont","city":"Irasburg","otherGeospatial":"Black River","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.374482,44.752937 ], [ -72.374482,44.875157 ], [ -72.195393,44.875157 ], [ -72.195393,44.752937 ], [ -72.374482,44.752937 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b16e4b07f02db6a5992","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":240254,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":49805,"text":"ofr96307 - 1996 - Level II scour analysis for Bridge 43 (BETHTH00070043) on Town Highway 07, crossing Gilead Brook, Bethel, Vermont","interactions":[],"lastModifiedDate":"2013-12-11T09:28:08","indexId":"ofr96307","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1996","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":"96-307","title":"Level II scour analysis for Bridge 43 (BETHTH00070043) on Town Highway 07, crossing Gilead Brook, Bethel, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nBETHTH00070043 on town highway 7 crossing Gilead Brook, Bethel, 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). A Level \nI study is included in Appendix E of this report. A Level I study provides a qualitative \ngeomorphic characterization of the study site. Information on the bridge available from \nVTAOT files was compiled prior to conducting Level I and Level II analyses and can be \nfound in Appendix D.
\nThe site is in the Green Mountain physiographic province of central Vermont in the town of \nBethel. The 6.81-mi2\n drainage area is in a predominantly rural and forested basin. In the \nvicinity of the study site, the banks have dense woody vegetation coverage except for the \ndownstream right bank near the bridge, which is grass covered.
\nIn the study area, Gilead Brook has an incised, slightly sinuous channel with a slope of \napproximately 0.0181 ft/ft, an average channel top width of 36 ft and an average channel \ndepth of 4.0 ft. The predominant channel bed material is cobble (D50 is 79.6 mm or 0.261\nft). The geomorphic assessment at the time of the Level I and Level II site visit on October \n19, 1994, indicated that the reach was stable.
\nThe town highway 7 crossing of Gilead Brook is a 31-ft-long, two-lane bridge consisting of \none 27-foot concrete slab type superstructure (Vermont Agency of Transportation, written \ncommun., August 24, 1994). The bridge is supported by vertical, concrete abutments with \nwingwalls. The channel is skewed approximately 30 degrees to the opening while the \nopening-skew-to-roadway is 15 degrees.
\nA scour hole 0.5 ft deeper than the mean thalweg depth was observed at the right side of the \ndownstream bridge face during the Level I assessment. The scour protection measures in \nplace at the site were type-1 stone fill (less than 12 inches diameter) along the right \nabutment and both downstream banks, type-2 stone fill (less than 36 inches diameter) on all \nof the road approach embankments, both upstream banks, and along the entire base length \nof the wingwalls. 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 1.4 ft. The worst-case \ncontraction scour occurred at the incipient overtopping discharge, which was between the \n100- and 500-year discharges. Abutment scour ranged from 6.6 to 11.0 ft. with the worst-case scenario occurring at the 500-year discharge. Additional information on scour depths \nand 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. \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-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). Many factors, \nincluding historical performance during flood events, the geomorphic assessment, scour \nprotection measures, and the results of the hydraulic analyses, must be considered to \nproperly assess the validity of abutment scour results. Therefore, scour depths adopted by \nVTAOT may differ from the computed values documented herein, based on the \nconsideration of additional contributing factors and experienced engineering judgement.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr96307","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Ivanoff, M.A., and Olson, S.A., 1996, Level II scour analysis for Bridge 43 (BETHTH00070043) on Town Highway 07, crossing Gilead Brook, Bethel, Vermont: U.S. Geological Survey Open-File Report 96-307, iv, 51 p., https://doi.org/10.3133/ofr96307.","productDescription":"iv, 51 p.","numberOfPages":"56","costCenters":[],"links":[{"id":179404,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96307.GIF"},{"id":279376,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0307/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Bethel","otherGeospatial":"Gilead Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.75,43.875 ], [ -72.75,44.0 ], [ -72.625,44.0 ], [ -72.625,43.875 ], [ -72.75,43.875 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a6121","contributors":{"authors":[{"text":"Ivanoff, Michael A.","contributorId":27105,"corporation":false,"usgs":true,"family":"Ivanoff","given":"Michael","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":240291,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"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":240290,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49781,"text":"ofr96191 - 1996 - Level II scour analysis for Bridge 33 (BETHTH00310033) on Town Highway 031, crossing Lilliesville Brook, Bethel, Vermont","interactions":[],"lastModifiedDate":"2013-12-06T15:33:29","indexId":"ofr96191","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1996","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":"96-191","title":"Level II scour analysis for Bridge 33 (BETHTH00310033) on Town Highway 031, crossing Lilliesville Brook, Bethel, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nBETHTH00310033 on town highway 31 crossing the Lilliesville Brook, Bethel, 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 study is included in Appendix E of this report. A Level I study provides \na qualitative geomorphic characterization of the study site. Information on the bridge \navailable from VTAOT files was compiled prior to conducting Level I and Level II \nanalyses and can be found in Appendix D.\nThe site is in the Green Mountain physiographic province of central Vermont in the town of \nBethel. The 6.85-mi2 drainage area is in a predominantly rural and forested basin. In the \nvicinity of the study site, the left banks have shrub and brush, and the right banks are \nforested.\nIn the study area, Lilliesville Brook has an incised, straight channel with a slope of \napproximately 0.02 ft/ft, an average channel top width of 37 ft and an average channel \ndepth of 4 ft. The predominant channel bed material is gravel and cobble (D50 is 66.8 mm or \n0.219 ft). The geomorphic assessment at the time of the Level I and Level II site visit on \nOctober 13 and 14, 1994, indicated that the reach was stable.\nThe town highway 31 crossing of Lilliesville Brook is a 41-ft-long, one-lane bridge \nconsisting of one 39-foot steel-beam span with a timber deck (Vermont Agency of \nTransportation, written commun., August 24, 1994). The bridge is supported by vertical, \nconcrete abutments with wingwalls. The channel is skewed approximately 35 degrees to the \nopening while the opening-skew-to-roadway is 0 degrees. \nScour protection measures in place at the site were type-1 stone fill (less than 12 inches \ndiameter) at the downstream left wingwall, left abutment, and upstream and downstream \nsides of the left road embankment. Additional details describing conditions at the site are \nincluded in the Level II Summary and Appendices D \nand E.\nScour depths and rock rip-rap sizes were computed using the general guidelines described \nin Hydraulic Engineering Circular 18 (Richardson and others, 1993). Scour depths were \ncalculated assuming an infinite depth of erosive material and a homogeneous particle-size \ndistribution. The scour analysis results are presented in tables 1 and 2 and a graph of the \nscour depths is presented in figure 8.","language":"English","publisher":"U.S. Geological Survey","doi":"10.3133/ofr96191","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Ivanoff, M.A., and Hammond, R.E., 1996, Level II scour analysis for Bridge 33 (BETHTH00310033) on Town Highway 031, crossing Lilliesville Brook, Bethel, Vermont: U.S. Geological Survey Open-File Report 96-191, iv, 28 p., https://doi.org/10.3133/ofr96191.","productDescription":"iv, 28 p.","numberOfPages":"33","costCenters":[],"links":[{"id":178508,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96191.png"},{"id":279415,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0191/report.pdf"}],"country":"United States","state":"Vermont","city":"Bethel","otherGeospatial":"Lilliesville Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.765979,43.790521 ], [ -72.765979,43.910383 ], [ -72.574443,43.910383 ], [ -72.574443,43.790521 ], [ -72.765979,43.790521 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b19e4b07f02db6a7786","contributors":{"authors":[{"text":"Ivanoff, Michael A.","contributorId":27105,"corporation":false,"usgs":true,"family":"Ivanoff","given":"Michael","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":240251,"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":240252,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49780,"text":"ofr96190 - 1996 - Level II scour analysis for Bridge 34 (BRIDTH00050034) on Town Highway 005, crossing North Branch Ottauquechee River, Bridgewater, Vermont","interactions":[],"lastModifiedDate":"2013-12-06T15:42:33","indexId":"ofr96190","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1996","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":"96-190","title":"Level II scour analysis for Bridge 34 (BRIDTH00050034) on Town Highway 005, crossing North Branch Ottauquechee River, Bridgewater, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nBRIDTH00050034 on town highway 5 crossing the North Branch Ottauquechee River, \nBridgewater, 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). A Level I study is included in Appendix E of this report. A Level I \nstudy provides a qualitative geomorphic characterization of the study site. Information on \nthe bridge available from VTAOT files was compiled prior to conducting Level I and Level \nII analyses and can be found in Appendix D.\nThe site is in the Green Mountain physiographic division of central Vermont in the town of \nBridgewater. The 5.45-mi2 drainage area is in a predominantly rural and forested basin. In \nthe vicinity of the study site, left and right banks are forested. Upstream of bridge 34, Town \nHighway 5 runs parallel to the right bank and DS of the bridge, parallel to the left bank.\nIn the study area, the North Branch Ottauquechee River has an incised channel with a slope \nof approximately 0.015 ft/ft, an average channel top width of 32 ft and an average channel \ndepth of 7 ft. The predominant channel bed material is sand and gravel (D50 is 105 mm or \n0.345 ft). The geomorphic assessment at the time of the Level I and Level II site visit on \nNovember 3, 1994, indicated that the reach was stable.\nThe town highway 31 crossing of Lilliesville Brook is a 41-ft-long, one-lane bridge consisting of one 39-foot steel-beam span with a timber deck (Vermont Agency of Transportation, written commun., August 24, 1994). The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 35 degrees to the opening while the opening-skew-to-roadway is 0 degrees. Scour protection measures in place at the site were type-1 stone fill (less than 12 inches diameter) at the downstream left wingwall, left abutment, and upstream and downstream sides of the left road embankment. Additional details describing conditions at the site are included in the Level II Summary and Appendices D and E. Scour depths and rock rip-rap sizes were computed using the general guidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1993). Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution. The scour analysis results are presented in tables 1 and 2 and a graph of the scour depths is presented in figure 8.","language":"English","publisher":"U.S. Geological Survey","doi":"10.3133/ofr96190","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Ayotte, J., 1996, Level II scour analysis for Bridge 34 (BRIDTH00050034) on Town Highway 005, crossing North Branch Ottauquechee River, Bridgewater, Vermont: U.S. Geological Survey Open-File Report 96-190, iv, 31 p., https://doi.org/10.3133/ofr96190.","productDescription":"iv, 31 p.","numberOfPages":"36","costCenters":[],"links":[{"id":178507,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/usgs_thumb.jpg"},{"id":279416,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0190/report.pdf"}],"country":"United States","state":"Vermont","city":"Bridgewater","otherGeospatial":"North Branch Ottauquechee River","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.758005,43.558839 ], [ -72.758005,43.694051 ], [ -72.577733,43.694051 ], [ -72.577733,43.558839 ], [ -72.758005,43.558839 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b19e4b07f02db6a751b","contributors":{"authors":[{"text":"Ayotte, Joseph D. jayotte@usgs.gov","contributorId":1802,"corporation":false,"usgs":true,"family":"Ayotte","given":"Joseph D.","email":"jayotte@usgs.gov","affiliations":[{"id":466,"text":"New England Water Science Center","active":true,"usgs":true}],"preferred":false,"id":240250,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":49779,"text":"ofr96189 - 1996 - Level II scour analysis for Bridge 38 (BETHTH00070038) on Town Highway 007, crossing Gilead Brook, Bethel, Vermont","interactions":[],"lastModifiedDate":"2013-12-06T16:14:29","indexId":"ofr96189","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1996","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":"96-189","title":"Level II scour analysis for Bridge 38 (BETHTH00070038) on Town Highway 007, crossing Gilead Brook, Bethel, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nBETHTH00070038 on town highway 7 crossing Gilead Brook, Bethel, 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). A Level \nI study is included in Appendix E of this report. A Level I study provides a qualitative \ngeomorphic characterization of the study site. Information on the bridge available from \nVTAOT files was compiled prior to conducting Level I and Level II analyses and can be \nfound in Appendix D.\nThe site is in the Green Mountain physiographic province of central Vermont in the town of \nBethel. The 8.83-mi2 drainage area is predominantly rural and forested. In the vicinity of \nthe study site, the banks have dense woody vegetation coverage.\nIn the study area, Gilead Brook is an incised, straight channel with a slope of approximately \n0.028 ft/ft, an average channel top width of 46 ft and an average channel depth of 3 ft. The \npredominant channel bed material is gravel (D50 is 43.9 mm or 0.144 ft). The geomorphic \nassessment at the time of the Level I and Level II site visit on October 18, 1994, indicated \nthat the reach was stable.\nThe town highway 5 crossing of the Black River is a 70-ft-long, two-lane bridge consisting of one 65-foot clear span (Vermont Agency of Transportation, written commun., August 2, 1994). The bridge is supported by vertical, concrete abutments with wingwalls. There is also a retaining wall along the upstream side of the road embankments. The channel is skewed approximately 20 degrees to the opening while the opening-skew-to-roadway is 15 degrees. A scour hole 3.0 ft deeper than the mean thalweg depth was observed along the right abutment. The scour hole was 27 feet long, 15 feet wide, and was 2.5 feet below the abutment footing at the time of the Level I assessment. This right abutment had numerous cracks and had settled. Additional details describing conditions at the site are included in the Level II Summary and Appendices D and E. Scour depths and rock rip-rap sizes were computed using the general guidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1993). Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution. The scour analysis results are presented in tables 1 and 2 and a graph of the scour depths is presented in figure 8.","language":"English","publisher":"U.S. Geological Survey","doi":"10.3133/ofr96189","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Ivanoff, M.A., and Song, D.L., 1996, Level II scour analysis for Bridge 38 (BETHTH00070038) on Town Highway 007, crossing Gilead Brook, Bethel, Vermont: U.S. Geological Survey Open-File Report 96-189, iv, 30 p., https://doi.org/10.3133/ofr96189.","productDescription":"iv, 30 p.","numberOfPages":"35","costCenters":[],"links":[{"id":178506,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/usgs_thumb.jpg"},{"id":279417,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0189/report.pdf"}],"country":"United States","state":"Vermont","city":"Bethel","otherGeospatial":"Gilead Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.765979,43.790521 ], [ -72.765979,43.910383 ], [ -72.574443,43.910383 ], [ -72.574443,43.790521 ], [ -72.765979,43.790521 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a62e7","contributors":{"authors":[{"text":"Ivanoff, Michael A.","contributorId":27105,"corporation":false,"usgs":true,"family":"Ivanoff","given":"Michael","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":240248,"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":240249,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49778,"text":"ofr96188 - 1996 - Level II scour analysis for Bridge 28 (BRIDTH00440028) on Town Highway 044 crossing Plymouth Brook, Bridgewater, Vermont","interactions":[],"lastModifiedDate":"2013-12-06T16:22:05","indexId":"ofr96188","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1996","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":"96-188","title":"Level II scour analysis for Bridge 28 (BRIDTH00440028) on Town Highway 044 crossing Plymouth Brook, Bridgewater, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nBRIDTH00440028 on town highway 44 crossing Plymouth Brook, Bridgewater, 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 study is included in Appendix E of this report. A Level I study provides \na qualitative geomorphic characterization of the study site. Information on the bridge \navailable from VTAOT files was compiled prior to conducting Level I and Level II \nanalyses and can be found in Appendix D.\nThe site is in the Green Mountain physiographic division of central Vermont in the town of \nBridgewater. The 11.3-mi2 drainage area is a predominantly rural basin. In the vicinity of \nthe study site, the left and right banks are pasture.\nIn the study area, Plymouth Brook has an incised channel with a slope of approximately \n0.0054 ft/ft, an average channel top width of 42 ft and an average channel depth of 3 ft. The \npredominant channel bed material is gravel (D50 is 62.3 mm or 0.204 ft). The geomorphic \nassessment at the time of the Level I and Level II site visit on November 9, 1994, indicated \nthat the reach was stable.\nThe town highway 5 crossing of the Black River is a 70-ft-long, two-lane bridge consisting of one 65-foot clear span (Vermont Agency of Transportation, written commun., August 2, 1994). The bridge is supported by vertical, concrete abutments with wingwalls. There is also a retaining wall along the upstream side of the road embankments. The channel is skewed approximately 20 degrees to the opening while the opening-skew-to-roadway is 15 degrees. A scour hole 3.0 ft deeper than the mean thalweg depth was observed along the right abutment. The scour hole was 27 feet long, 15 feet wide, and was 2.5 feet below the abutment footing at the time of the Level I assessment. This right abutment had numerous cracks and had settled. Additional details describing conditions at the site are included in the Level II Summary and Appendices D and E. Scour depths and rock rip-rap sizes were computed using the general guidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1993). Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution. The scour analysis results are presented in tables 1 and 2 and a graph of the scour depths is presented in figure 8.","language":"English","publisher":"U.S. Geological Survey","doi":"10.3133/ofr96188","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Olson, S.A., and Ayotte, J., 1996, Level II scour analysis for Bridge 28 (BRIDTH00440028) on Town Highway 044 crossing Plymouth Brook, Bridgewater, Vermont: U.S. Geological Survey Open-File Report 96-188, iv, 30 p., https://doi.org/10.3133/ofr96188.","productDescription":"iv, 30 p.","numberOfPages":"35","costCenters":[],"links":[{"id":178505,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/usgs_thumb.jpg"},{"id":279418,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0188/report.pdf"}],"country":"United States","state":"Vermont","city":"Bridgewater","otherGeospatial":"Plymouth Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.758005,43.558839 ], [ -72.758005,43.694051 ], [ -72.577733,43.694051 ], [ -72.577733,43.558839 ], [ -72.758005,43.558839 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b19e4b07f02db6a7fb9","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":240247,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Ayotte, Joseph D. jayotte@usgs.gov","contributorId":1802,"corporation":false,"usgs":true,"family":"Ayotte","given":"Joseph D.","email":"jayotte@usgs.gov","affiliations":[{"id":466,"text":"New England Water Science Center","active":true,"usgs":true}],"preferred":false,"id":240246,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49777,"text":"ofr96187 - 1996 - Level II scour analysis for Bridge 42 (RANDVT00120042) on State Highway 12, crossing Third Branch White River, Randolph, Vermont","interactions":[],"lastModifiedDate":"2013-12-11T13:12:36","indexId":"ofr96187","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1996","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":"96-187","title":"Level II scour analysis for Bridge 42 (RANDVT00120042) on State Highway 12, crossing Third Branch White River, Randolph, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nRANDVT00120042 on State Highway 12 crossing the Third Branch White River, \nRandolph, 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). A Level I study is included in Appendix E of this report. A Level I \nstudy provides a qualitative geomorphic characterization of the study site. Information on \nthe bridge available from VTAOT files was compiled prior to conducting Level I and Level \nII analyses and can be found in Appendix D.
\nThe site is in the Green Mountain physiographic division of central Vermont in the town of \nRandolph. The 61.9-mi2\n drainage area is in a predominantly rural drainage basin. In the \nvicinity of the study site, the left and right banks have moderate tree cover with residential \nand commercial buildings on the overbank areas.
\nIn the study area, the Third Branch White River has a sinuous channel with a slope of \napproximately 0.013 ft/ft, an average channel top width of 133 ft and an average channel \ndepth of 5 ft. The predominant channel bed material is gravel with a median grain size ( \nD50) of 49.6 mm (0.163 ft). Bank material is sand and gravel (D50 is 3.08 mm or 0.010 ft). \nThe geomorphic assessment at the time of the Level I site visits on July 8, 1994 and \nDecember 13, 1994, indicated that the reach has experienced vertical degradation. A drop \nstructure has been constructed downstream of the bridge to prevent further degradation. In \naddition to the degradation of the stream bed, there is local pier scour at the bridge site as \nwell. At the nose of the pier in the main channel, the bed is approximately three feet below \nthe mean thalweg and two feet below the bottom of the pier footing.
\nThe State Highway 12 crossing of the Third Branch White Riveris a 220-ft-long, two-lane\nbridge consisting of four concrete spans. The maximum span length is 57 ft. (Vermont \nAgency of Transportation, written commun., July 29, 1994). The bridge is supported by \nvertical, concrete abutments and three concrete piers. The toe of the left abutment is at the \nchannel edge. The toe of the right abutment is set back on the right over-bank. The roadway \ncenterline on the structure has a slight horizontal curve; however, the main channel is \nskewed approximately 5 degrees to the bridge. Additional details describing conditions at \nthe 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 \nin Hydraulic Engineering Circular 18 (Richardson and others, 1993). Scour depths were \ncalculated assuming an infinite depth of erosive material and a homogeneous particle-size \ndistribution. The scour analysis results are presented in tables 1 and 2 and a graph of the \nscour depths is presented in figure 8.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr96187","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Olson, S.A., and Weber, M.A., 1996, Level II scour analysis for Bridge 42 (RANDVT00120042) on State Highway 12, crossing Third Branch White River, Randolph, Vermont: U.S. Geological Survey Open-File Report 96-187, iv, 28 p., https://doi.org/10.3133/ofr96187.","productDescription":"iv, 28 p.","numberOfPages":"33","costCenters":[],"links":[{"id":178504,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96187.GIF"},{"id":279419,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0187/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Randolph","otherGeospatial":"Third Branch White River","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.75,43.875 ], [ -72.75,44.0 ], [ -72.625,44.0 ], [ -72.625,43.875 ], [ -72.75,43.875 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a6153","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":240244,"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":240245,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49776,"text":"ofr96161 - 1996 - Level II scour analysis for Bridge 10 (NORWTH00120010) Town Highway 012 Bloody Brook, Norwich, Vermont","interactions":[],"lastModifiedDate":"2013-12-11T13:21:05","indexId":"ofr96161","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1996","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":"96-161","title":"Level II scour analysis for Bridge 10 (NORWTH00120010) Town Highway 012 Bloody Brook, Norwich, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nNORWTH00120010 on town highway 12 crossing Bloody Brook, Norwich, 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 study is included in Appendix E of this report. A Level I study provides \na qualitative geomorphic characterization of the study site. Information on the bridge, \navailable from VTAOT files, was compiled prior to conducting the Level I and Level II \nanalyses and can be found in Appendix D.
\nThe site is in the New England Upland physiographic province in east-central Vermont. The \n8.98-mi2\n drainage area is in a predominantly rural and forested basin. In the vicinity of the \nstudy site, the left bank upstream and the left and right banks downstream are forested. The \nimmediate right bank upstream is covered by shrub and brush with pasture on the overbank. \nTown Highway 12 runs along the valley of Bloody Brook; however, at structure \nNORWTH00120010 the road crosses Bloody Brook at a 90-degree angle.
\nIn the study area, Bloody Brook has a sinuous channel with a slope of approximately 0.014 \nft/ft, an average channel top width of 41 ft and an average channel depth of 3 ft. The \npredominant channel bed materials are gravel and cobble (D50 is 51.0 mm or 0.167 ft). The \ngeomorphic assessment at the time of the Level I site visit on October 31, 1994, indicated \nthat the reach was unstable.
\nThe town highway 12 crossing of Bloody Brook is a 34-ft-long, two-lane bridge consisting \nof one 30-foot clear span (Vermont Agency of Transportation, written commun., July 29, \n1994). The bridge is supported by vertical, concrete abutments with wingwalls. The right \nabutment is protected by sparse type-2 stone fill (less than 24 inches diameter). The channel \nis skewed 0 degrees to the opening and the opening-skew-to-roadway is 0 degrees. \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, 1993). Scour depths were \ncalculated assuming an infinite depth of erosive material and a homogeneous particle-size \ndistribution. The scour analysis results are presented in tables 1 and 2 and a graph of the \nscour depths is presented in figure 8.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr96161","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Ayotte, J., 1996, Level II scour analysis for Bridge 10 (NORWTH00120010) Town Highway 012 Bloody Brook, Norwich, Vermont: U.S. Geological Survey Open-File Report 96-161, iv, 31 p., https://doi.org/10.3133/ofr96161.","productDescription":"iv, 31 p.","numberOfPages":"36","costCenters":[],"links":[{"id":178503,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96161.GIF"},{"id":279420,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0161/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Norwich","otherGeospatial":"Bloody Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.375,43.625 ], [ -72.375,43.75 ], [ -72.25,43.75 ], [ -72.25,43.625 ], [ -72.375,43.625 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a5ad9","contributors":{"authors":[{"text":"Ayotte, Joseph D. jayotte@usgs.gov","contributorId":1802,"corporation":false,"usgs":true,"family":"Ayotte","given":"Joseph D.","email":"jayotte@usgs.gov","affiliations":[{"id":466,"text":"New England Water Science Center","active":true,"usgs":true}],"preferred":false,"id":240243,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":49775,"text":"ofr96160 - 1996 - Level II scour analysis for Bridge 46 (NORWTH00030046) Town Highway 3 (VT132) crossing the Ompompanoosuc River, Norwich, Vermont","interactions":[],"lastModifiedDate":"2013-12-12T11:32:20","indexId":"ofr96160","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1996","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":"96-160","title":"Level II scour analysis for Bridge 46 (NORWTH00030046) Town Highway 3 (VT132) crossing the Ompompanoosuc River, Norwich, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nNORWTH00030046 on town highway 3, which is also Vermont State Route 132 crossing \nthe Ompompanoosuc River, Norwich, Vermont (figures 1–8). A Level II study is a basic \nengineering analysis of the site, including a quantitative analysis of stream stability and \nscour (U.S. Department of Transportation, 1993). A Level I study is included in Appendix \nE of this report. A Level I study provides a qualitative geomorphic characterization of the \nstudy site. Information on the bridge, available from VTAOT files, was compiled prior to \nconducting Level I and Level II analyses and can be found in Appendix D.\nThe site is in the New England Upland physiographic province of east-central Vermont. \nThe 135-mi2\n drainage area is a predominantly rural basin. A flood-control reservoir located \napproximately 2 mi upstream has 1.66 billion cubic feet of usable storage. In the vicinity of \nthe study site, the left bank is forested and the right bank is covered by shrubs and brush, \nadjacent to woods. The Ompompanoosuc River is parallel to Town Highway 3.\nIn the study area, the Ompompanoosuc River has a sinuous channel with a slope of \napproximately 0.003 ft/ft, an average channel top width of 166 ft and an average channel \ndepth of 6 ft. The predominant channel bed material is sand (D50 is 0.744 mm or 0.00244\nft). The geomorphic assessment at the time of the Level I and Level II site visit on August \n19, 1994, indicated that the reach was stable.\nThe town highway 3 crossing of the Ompompanoosuc Riveris a 100-ft-long, two-lane\nbridge consisting of two steel-beam spans (Vermont Agency of Transportation, written \ncommun., July 29, 1994). The bridge is supported by vertical, concrete abutments with \nwingwalls. The channel is skewed approximately 25 degrees to the opening while the \nopening-skew-to-roadway is 12 degrees. Additional details describing conditions at the site \nare included in the Level II Summary and Appendices D \nand E.\nScour depths and rock rip-rap sizes were computed using the general guidelines described \nin Hydraulic Engineering Circular 18 (Richardson and others, 1993). Scour depths were \ncalculated assuming an infinite depth of erosive material and a homogeneous particle-size \ndistribution. The scour analysis results are presented in tables 1 and 2 and a graph of the \nscour depths is presented in figure 8.","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr96160","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Olson, S.A., and Song, D.L., 1996, Level II scour analysis for Bridge 46 (NORWTH00030046) Town Highway 3 (VT132) crossing the Ompompanoosuc River, Norwich, Vermont: U.S. Geological Survey Open-File Report 96-160, iv, 28 p., https://doi.org/10.3133/ofr96160.","productDescription":"iv, 28 p.","numberOfPages":"33","costCenters":[],"links":[{"id":179330,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96160.PNG"},{"id":279421,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0160/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Norwich","otherGeospatial":"Ompompanoosuc River","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.25,43.75 ], [ -72.25,43.875 ], [ -72.125,43.875 ], [ -72.125,43.75 ], [ -72.25,43.75 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a607a","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":240241,"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":240242,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49809,"text":"ofr96311 - 1996 - Level II scour analysis for Bridge 46 (BRIDTH00050046) on Town Highway 05, crossing North Branch Ottauquechee River, Bridgewater, Vermont","interactions":[],"lastModifiedDate":"2013-12-10T15:55:53","indexId":"ofr96311","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1996","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":"96-311","title":"Level II scour analysis for Bridge 46 (BRIDTH00050046) on Town Highway 05, crossing North Branch Ottauquechee River, Bridgewater, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nBRIDTH00050046 on town highway 5 crossing the North Branch Ottauquechee River, \nBridgewater, 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). A Level I study is included in Appendix E of this report. A Level I \nstudy provides a qualitative geomorphic characterization of the study site. Information on \nthe bridge, gleaned from Vermont Agency of Transportation (VTAOT) files was compiled \nprior to conducting Level I and Level II analyses and can be found in Appendix D.
\nThe site is in the Green Mountain physiographic province of central Vermont in the town of \nBridgewater. The 5.61-mi2\n drainage area is a predominantly rural and forested basin. In the \nvicinity of the study site, the banks are forested. Town highway 5 parallels the upstream left \nbank.
\nIn the study area, the North Branch Ottauquechee River has a sinuous channel with a slope \nof approximately 0.015 ft/ft, an average channel top width of 48 ft and an average channel \ndepth of 6 ft. The predominant channel bed materials are gravel and cobble with a median \ngrain size (D50) of 66.2 mm (0.217 ft). The geomorphic assessment at the time of the Level \nI and Level II site visit on November 2 and 3, 1994, indicated that the reach was stable.
\nThe town highway 5 crossing of North Branch Ottauquechee Riveris a 40-ft-long, one-lane\nbridge consisting of a 34-ft steel-beam span, supported by vertical abutments with no \nwingwalls (Vermont Agency of Transportation, written communication, August 25, 1994). \nThe left abutment is stone; the right abutment is log cribwork with type-2 stone fill (less \nthan 36 inches diameter) along its base. Type-2 stone fill has also been placed on the \nupstream and downstream sides of the road embankments, except the upstream left which \nhas type-3 (less than 48 inches diameter). The channel is skewed approximately 60 degrees; \nthe opening-skew-to-roadway is 30 degrees. Additional details describing conditions at the \nsite are included in the Level II Summary, Appendix D, and Appendix E.
\nScour depths and rock rip-rap sizes were computed using the general guidelines described \nin Hydraulic Engineering Circular 18 (Richardson and others, 1993).
\nTotal scour at a highway crossing is comprised of three components: 1) long-term \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 these computed results \nfollow.
\nContraction scour for all modelled flows was 0.0 ft. Abutment scour ranged from 5.7 ft to \n7.7 ft. with the worst-case abutment scour occurring 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 depths, are presented in \ntables 1 and 2. A cross-section of the computed scour at the bridge is presented in figure 8. \nScour 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, 1993, p. 22). Many factors, \nincluding historical performance during flood events, the geomorphic assessment, scour \nprotection, and the results of the hydraulic analyses, must be considered to properly assess \nthe validity of abutment scour results. Therefore, scour depths adopted by VTAOT may \ndiffer from the computed values documented herein, based on the consideration of \nadditional contributing factors and experienced engineering judgement.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr96311","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Olson, S.A., and Song, D.L., 1996, Level II scour analysis for Bridge 46 (BRIDTH00050046) on Town Highway 05, crossing North Branch Ottauquechee River, Bridgewater, Vermont: U.S. Geological Survey Open-File Report 96-311, iv, 30 p., https://doi.org/10.3133/ofr96311.","productDescription":"iv, 30 p.","numberOfPages":"35","costCenters":[],"links":[{"id":179408,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96311.GIF"},{"id":279366,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0311/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Bridgewater","otherGeospatial":"North Branch Ottauquechee River","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":"4f4e4b17e4b07f02db6a60ef","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":240297,"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":240298,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ]}