This report provides the results of a detailed Level II analysis of scour potential at structure HANCTH00010010 on town highway 1 crossing the White River, Hancock, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including a quantitative analysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of a Level I scour investigation also are included in Appendix E of this report. A Level I investigation provides a qualitative geomorphic characterization of the study site. Information on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is found in Appendix D.
\nThe site is in the Green Mountain section of the New England physiographic province of central Vermont. The 59.8-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is primarily grass with trees and brush on the immediate channel banks.
\nIn the study area, the White River has a sinuous channel with a slope of approximately 0.005 ft/ft, an average channel top width of 104 ft and an average channel depth of 6 ft. The predominant channel bed materials are gravel and cobble with a median grain size (D50) of 98.9 mm (0.325 ft). The geomorphic assessment at the time of the Level I and Level II site visit on November 15, 1994, indicated that the reach was stable.
\nThe town highway 1 crossing of the White River is a 91-ft-long, two-lane bridge consisting of one 89-foot steel-beam span (Vermont Agency of Transportation, written communication, August 26, 1994). The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 15 degrees to the opening while the opening-skew-to-roadway is 0 degrees. Additional details describing conditions at the site are included in the Level II Summary and Appendices D and E.
\nScour depths and rock rip-rap sizes were computed using the general guidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995). Total scour at a highway crossing is comprised of three components: 1) long-term streambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is the sum of the three components. Equations are available to compute depths for contraction and local scour and a summary of the results of these computations follows.
\nContraction scour for all modelled flows was 0.0 feet. Abutment scour ranged from 13.1 to 17.1 ft. The worst-case abutment scour occurred at the 500-year discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution.
\nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, computed scour depths are evaluated in combination with other information including (but not limited to) historical performance during flood events, the geomorphic stability assessment, existing scour protection measures, and the results of the hydraulic analyses. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr96570","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 10 (HANCTH00010010) on Town Highway 1, crossing the White River, Hancock, Vermont: U.S. Geological Survey Open-File Report 96-570, iv, 51 p., https://doi.org/10.3133/ofr96570.","productDescription":"iv, 51 p.","numberOfPages":"56","costCenters":[],"links":[{"id":162560,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96570.PNG"},{"id":279291,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0570/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Hancock","otherGeospatial":"White River","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.875,43.875 ], [ -72.875,44.0 ], [ -72.75,44.0 ], [ -72.75,43.875 ], [ -72.875,43.875 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b1ae4b07f02db6a8456","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":240342,"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":240343,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49835,"text":"ofr96569 - 1996 - Level II scour analysis for Bridge 28 (HARDTH00300028) on Town Highway 30, crossing the Lamoille River, Hardwick, Vermont","interactions":[],"lastModifiedDate":"2013-12-10T10:22:12","indexId":"ofr96569","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":"96-569","title":"Level II scour analysis for Bridge 28 (HARDTH00300028) on Town Highway 30, crossing the Lamoille River, Hardwick, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure HARDTH00300028 on town highway 30 crossing the Lamoille River, Hardwick, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including a quantitative analysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of a Level I scour investigation also are included in Appendix E of this report. A Level I investigation provides a qualitative geomorphic characterization of the study site. Information on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is found in Appendix D.
\nThe site is in the New England Upland section of the New England physiographic province in north-central Vermont. The 63.7-mi
In the study area, the Lamoille River has an incised, sinuous channel with a slope of approximately 0.002 ft/ft, an average channel top width of 76 ft and an average bank height of 6 ft. The predominant channel bed materials are gravel and cobble with a median grain size (D50) of 46.6 mm (0.153 ft). The geomorphic assessment at the time of the Level I and Level II site visit on July 25, 1995, indicated that the reach was laterally unstable. The site was revisited on August 21, 1995, after the August 5-6, 1995 flood on the Lamoille River. Findings from this follow-up visit are presented in Appendix G.
\nThe town highway 30 crossing of the Lamoille River is a 54-ft-long, one-lane bridge consisting of one 52-foot steel-beam span (Vermont Agency of Transportation, written communication, April 3, 1995). The bridge is supported by vertical, stone abutments with wingwalls. Scour, about one foot below the mean thalweg, exists along the right abutment and right upstream wingwall. Sheet piling has been driven around the right abutment and wingwalls and filled with concrete. The channel is skewed approximately 5 degrees to the opening while the opening-skew-to-roadway is 0 degrees. Additional details describing conditions at the site are included in the Level II Summary and Appendices D and E.
\nScour depths and rock rip-rap sizes were computed using the general guidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995). Total scour at a highway crossing is comprised of three components: 1) long-term streambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is the sum of the three components. Equations are available to compute depths for contraction and local scour and a summary of the results of these computations follows.
\nContraction scour for all modelled flows ranged from 1.9 to 2.5 ft. The worst-case contraction scour occurred at the 100-year discharge. Abutment scour ranged from 11.2 to 17.8 ft. The worst-case abutment scour occurred at the 500-year discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution.
\nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, computed scour depths are evaluated in combination with other information including (but not limited to) historical performance during flood events, the geomorphic stability assessment, existing scour protection measures, and the results of the hydraulic analyses. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr96569","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Olson, S.A., and Degnan, J.R., 1996, Level II scour analysis for Bridge 28 (HARDTH00300028) on Town Highway 30, crossing the Lamoille River, Hardwick, Vermont: U.S. Geological Survey Open-File Report 96-569, iv, 64 p., https://doi.org/10.3133/ofr96569.","productDescription":"iv, 64 p.","numberOfPages":"69","costCenters":[],"links":[{"id":162559,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96569.PNG"},{"id":279292,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0569/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\": [ [ [ -72.375,44.5 ], [ -72.375,44.625 ], [ -72.25,44.625 ], [ -72.25,44.5 ], [ -72.375,44.5 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b19e4b07f02db6a7f87","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":240341,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Degnan, James R. 0000-0002-5665-9010 jrdegnan@usgs.gov","orcid":"https://orcid.org/0000-0002-5665-9010","contributorId":498,"corporation":false,"usgs":true,"family":"Degnan","given":"James","email":"jrdegnan@usgs.gov","middleInitial":"R.","affiliations":[{"id":405,"text":"NH/VT office of New England Water Science Center","active":true,"usgs":true},{"id":466,"text":"New England Water Science Center","active":true,"usgs":true}],"preferred":true,"id":240340,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49834,"text":"ofr96568 - 1996 - Level II scour analysis for Bridge 45b (BRIDTH00040045b) on Town Highway 4, crossing an unnamed Dailey Hollow Branch Tributary, Bridgewater, Vermont","interactions":[],"lastModifiedDate":"2013-12-10T10:32:37","indexId":"ofr96568","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":"96-568","title":"Level II scour analysis for Bridge 45b (BRIDTH00040045b) on Town Highway 4, crossing an unnamed Dailey Hollow Branch Tributary, Bridgewater, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure BRIDTH0004045B on town highway 4 crossing an unnamed Dailey Hollow Branch Tributary, Bridgewater, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including a quantitative analysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of a Level I scour investigation also are included in Appendix E of this report. A Level I investigation provides a qualitative geomorphic characterization of the study site. Information on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is found in Appendix D.
\nThe site is in the Green Mountain section of the New England physiographic province in central Vermont. The 2.47-mi2 drainage area is in a predominantly rural and forested basin. Surface cover in the vicinity of the study site is variable. A gravel road is adjacent to the left bank with the immediate upstream left bank covered by grass and the immediate downstream left bank covered by shrubs and brush. The upstream right bank is densely forested; the downstream right overbank is covered by grass with trees and brush on the immediate channel bank.
\nIn the study area, this unnamed Dailey Hollow Branch Tributary has an incised channel with a slope of approximately 0.04 ft/ft, an average channel top width of 29 ft and an average channel depth of 4 ft. The predominant channel bed material is gravel with a median grain size (D50) of 47.0 mm (0.154 ft). The geomorphic assessment at the time of the Level I and Level II site visit on November 15, 1994, indicated that the reach was stable.
\nThe town highway 4 crossing of the unnamed Dailey Hollow Branch Tributary is a 62-ft-long, corrugated steel multi-plate arch structure. It is supported by concrete footings leaving natural stream bed exposed (Vermont Agency of Transportation, written communication, January, 1996). The road embankments are protected by stone fill, however, the size is unknown due to sand and grass covering the fill except for the upstream left embankment which has type-2 stone fill (less than 36 inches diameter). The downstream left bank is protected by type-3 stone fill (less than 48 inches diameter) extending 25 feet downstream of the culvert. The channel approach to the culvert has a mild s-curve bend with the opening skewed ten degrees to flow. Additional details describing conditions at the site are included in the Level II Summary and Appendices D and E.
\nScour depths and rock rip-rap sizes were computed using the general guidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1993). Total scour at a highway crossing is comprised of three components: 1) long-term streambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is the sum of the three components. Equations are available to compute depths for contraction and local scour and a summary of the results of these computations follows.
\nContraction scour for all modelled flows ranged from 1.1 to 1.8 ft. The worst-case contraction scour occurred at the 500-year discharge. Abutment scour ranged from 7.7 to 11.7 ft. The worst-case abutment scour occurred at the 500-year discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution.
\nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1993, p. 48). Usually, computed scour depths are evaluated in combination with other information including (but not limited to) historical performance during flood events, the geomorphic stability assessment, existing scour protection measures, and the results of the hydraulic analyses. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr96568","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Boehmler, E.M., 1996, Level II scour analysis for Bridge 45b (BRIDTH00040045b) on Town Highway 4, crossing an unnamed Dailey Hollow Branch Tributary, Bridgewater, Vermont: U.S. Geological Survey Open-File Report 96-568, iv, 47 p., https://doi.org/10.3133/ofr96568.","productDescription":"iv, 47 p.","numberOfPages":"52","costCenters":[],"links":[{"id":162558,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96568.PNG"},{"id":279293,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0568/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Bridgewater","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":"4f4e4b17e4b07f02db6a60e8","contributors":{"authors":[{"text":"Boehmler, Erick M.","contributorId":96303,"corporation":false,"usgs":true,"family":"Boehmler","given":"Erick","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":240339,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":49833,"text":"ofr96567 - 1996 - Level II scour analysis for Bridge 41 (WODSTH00750041) on Town Highway 75, crossing Happy Valley Brook, Woodstock, Vermont","interactions":[],"lastModifiedDate":"2013-12-10T13:34:43","indexId":"ofr96567","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":"96-567","title":"Level II scour analysis for Bridge 41 (WODSTH00750041) on Town Highway 75, crossing Happy Valley Brook, Woodstock, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure WODSTH00750041 on town highway 75 crossing Happy Valley Brook, Woodstock, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including a quantitative analysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of a Level I scour investigation also are included in Appendix E of this report. A Level I investigation provides a qualitative geomorphic characterization of the study site. Information on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is found in Appendix D.
\nThe site is in the New England Upland section of the New England physiographic province of east-central Vermont. The 3.45-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is brush with scattered trees.
\nIn the study area, Happy Valley Brook has an incised, sinuous channel with a slope of approximately 0.03 ft/ft, an average channel top width of 23 ft and an average channel depth of 5 ft. The predominant channel bed materials are gravel and cobble with a median grain size (D50) of 82.8 mm (0.272 ft). The geomorphic assessment at the time of the Level II site visits on September 13, 1994 and December 14, 1994, indicated that the reach was degrading. Five logs are embedded across the channel under the bridge in an attempt to prevent further degradation (see Figures 5 and 6).
\nThe town highway 75 crossing of Happy Valley Brook is a 27-ft-long, two-lane bridge consisting of one 25-foot steel-beam span. The clear span is 17 ft. (Vermont Agency of Transportation, written communication, August 3, 1994). The bridge is supported by vertical, stone abutments with wingwalls. The channel is skewed approximately 40 degrees to the opening and the opening-skew-to-roadway is also 40 degrees. Additional details describing conditions at the site are included in the Level II Summary and Appendices D and E.
\nScour depths and rock rip-rap sizes were computed using the general guidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995). Total scour at a highway crossing is comprised of three components: 1) long-term streambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is the sum of the three components. Equations are available to compute depths for contraction and local scour and a summary of the results of these computations follows.
\nContraction scour for all modelled flows ranged from 1.3 to 2.2 ft. The worst-case contraction scour occurred at the 500-year discharge. Abutment scour ranged from 7.2 to 12.0 ft. The worst-case abutment scour occurred at the 500-year discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution.
\nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, computed scour depths are evaluated in combination with other information including (but not limited to) historical performance during flood events, the geomorphic stability assessment, existing scour protection measures, and the results of the hydraulic analyses. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr96567","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Olson, S.A., 1996, Level II scour analysis for Bridge 41 (WODSTH00750041) on Town Highway 75, crossing Happy Valley Brook, Woodstock, Vermont: U.S. Geological Survey Open-File Report 96-567, iv, 48 p., https://doi.org/10.3133/ofr96567.","productDescription":"iv, 48 p.","numberOfPages":"53","costCenters":[],"links":[{"id":162557,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96567.PNG"},{"id":279294,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0567/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Woodstock","otherGeospatial":"Happy Valley Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.5,43.625 ], [ -72.5,43.75 ], [ -72.375,43.75 ], [ -72.375,43.625 ], [ -72.5,43.625 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a619d","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":240338,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":49832,"text":"ofr96566 - 1996 - Level II scour analysis for Bridge 96 (BLOOVT01050096) on Vermont Route 105, crossing Nulhegan River, Bloomfield, Vermont","interactions":[],"lastModifiedDate":"2013-12-10T13:38:00","indexId":"ofr96566","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":"96-566","title":"Level II scour analysis for Bridge 96 (BLOOVT01050096) on Vermont Route 105, crossing Nulhegan River, Bloomfield, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure BLOOVT01050096 on Vermont Route 105 crossing the Nulhegan River, Bloomfield, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including a quantitative analysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of a Level I scour investigation also are included in Appendix E of this report. A Level I investigation provides a qualitative geomorphic characterization of the study site. Information on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is found in Appendix D.
\nThe site is in the White Mountain section of the New England physiographic province of north-east Vermont in the town of Bloomfield. The 103-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is shrub and brushland upstream. Downstream of the bridge, the surface cover is forest.
\nIn the study area, the Nulhegan River has an incised, sinuous channel with a slope of approximately 0.015 ft/ft, an average channel top width of 78 ft and an average channel depth of 5 ft. The predominant channel bed material is cobble with a median grain size (D50) of 133 mm (0.435 ft). About 100 feet upstream, the streambed and bank materials abruptly change predominantly to sand. The geomorphic assessment at the time of the Level I and Level II site visit on July 6, 1995, indicated that the upstream reach, which is experiencing channel scour and severe bank cutting into the alluvial channel boundaries, is not stable. The downstream reach is semi- to non-alluvial and is assessed as stable.
\nThe Vermont Route 105 crossing of the Nulhegan River is a 74-ft-long, two-lane bridge consisting of one 71-foot steel stringer type superstructure with a concrete deck (Vermont Agency of Transportation, written communication, August 5, 1994). The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 10 degrees to the opening while the opening-skew-to-roadway is 25 degrees.
\nA scour hole 4.0 ft deeper than the mean thalweg depth was observed along the upstream channel during the Level I assessment. Scour protection measures at the site consist of type-2 stone fill (less than 24 inches diameter) along the entire base length of both abutments and all wingwalls. Additional details describing 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 in Hydraulic Engineering Circular 18 (Richardson and others, 1995). Total scour at a highway crossing is comprised of three components: 1) long-term streambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is the sum of the three components. Equations are available to compute depths for contraction and local scour and a summary of the results of these computations follows.
\nContraction scour for all modelled flows ranged from 0.5 to 1.1 ft. The worst-case contraction scour occurred at the 500-year discharge. Abutment scour ranged from 10.5 to 16.2 ft. The worst-case abutment scour also occurred at the 500-year discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution.
\nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, computed scour depths are evaluated in combination with other information including (but not limited to) historical performance during flood events, the geomorphic stability assessment, existing scour protection measures, and the results of the hydraulic analyses. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr96566","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Ayotte, J., and Ivanoff, M.A., 1996, Level II scour analysis for Bridge 96 (BLOOVT01050096) on Vermont Route 105, crossing Nulhegan River, Bloomfield, Vermont: U.S. Geological Survey Open-File Report 96-566, iv, 48 p., https://doi.org/10.3133/ofr96566.","productDescription":"iv, 48 p.","numberOfPages":"53","costCenters":[],"links":[{"id":162556,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96566.PNG"},{"id":279295,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0566/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Bloomfield","otherGeospatial":"Nulhegan River","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -71.75,44.75 ], [ -71.75,44.875 ], [ -71.625,44.875 ], [ -71.625,44.75 ], [ -71.75,44.75 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b16e4b07f02db6a559d","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":240336,"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":240337,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49831,"text":"ofr96565 - 1996 - Level II scour analysis for Bridge 42 (HARDELMSTR0042) on Elm Street, crossing Cooper Brook, Hardwick, Vermont","interactions":[],"lastModifiedDate":"2013-12-10T13:41:46","indexId":"ofr96565","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":"96-565","title":"Level II scour analysis for Bridge 42 (HARDELMSTR0042) on Elm Street, crossing Cooper Brook, Hardwick, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure HARDELMSTR0042 on Elm Street crossing Cooper Brook, Hardwick, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including a quantitative analysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of a Level I scour investigation also are included in Appendix E of this report. A Level I investigation provides a qualitative geomorphic characterization of the study site. Information on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is found in Appendix D.
\nThe site is in the New England Upland section of the New England physiographic province in north-central Vermont. The 16.6-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the overbanks are primarily grass covered with some brush along the immediate channel banks except the upstream right bank and overbank which is forested and the downstream left overbank which has a lumberyard.
\nIn the study area, Cooper Brook has a sinuous channel with a slope of approximately 0.005 ft/ft, an average channel top width of 50 ft and an average channel depth of 6 ft. The predominant channel bed materials are sand and gravel with a median grain size (D50) of 1.25 mm (0.00409 ft). The geomorphic assessment at the time of the Level I and Level II site visit on July 24, 1995, indicated that the reach was stable.
\nThe Elm Street crossing of Cooper Brook is a 39-ft-long, two-lane bridge consisting of one 37-foot concrete span (Vermont Agency of Transportation, written communication, March 17, 1995). The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 40 degrees to the opening while the opening-skew-to-roadway is 45 degrees.
\nOn August 17, 1995 the site was revisited to investigate the effect of the August 4-5, 1995 flood on the structure. Channel features such as scour holes and point bars were shifted by the high flow event. Details of these changes can be found in the Level I data form in Appendix E. Additional details describing conditions at the site are included in the Level II Summary and Appendices D and G.
\nScour depths and rock rip-rap sizes were computed using the general guidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1993). Total scour at a highway crossing is comprised of three components: 1) long-term streambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is the sum of the three components. Equations are available to compute depths for contraction and local scour and a summary of the results of these computations follows.
\nContraction scour for all modelled flows ranged from 0.0 to 3.4 ft. The worst-case contraction scour occurred at the incipient-overtopping discharge which was less than the 100-year discharge. Abutment scour ranged from 7.1 to 10.4 ft. The worst-case abutment scour occurred at the 500-year discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution.
\nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1993, p. 48). Usually, computed scour depths are evaluated in combination with other information including (but not limited to) historical performance during flood events, the geomorphic stability assessment, existing scour protection measures, and the results of the hydraulic analyses. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr96565","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Olson, S.A., 1996, Level II scour analysis for Bridge 42 (HARDELMSTR0042) on Elm Street, crossing Cooper Brook, Hardwick, Vermont: U.S. Geological Survey Open-File Report 96-565, iv, 55 p., https://doi.org/10.3133/ofr96565.","productDescription":"iv, 55 p.","numberOfPages":"60","costCenters":[],"links":[{"id":162471,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96565.PNG"},{"id":279296,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0565/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Hardwick","otherGeospatial":"Cooper Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.5,44.375 ], [ -72.5,44.625 ], [ -72.25,44.625 ], [ -72.25,44.375 ], [ -72.5,44.375 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a5fc4","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":240335,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":49828,"text":"ofr96562 - 1996 - Level II scour analysis for Bridge 28 (MNTGTH00190028) on Town Highway 19, crossing Wade Brook, Montgomery, Vermont","interactions":[],"lastModifiedDate":"2013-12-10T13:43:38","indexId":"ofr96562","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":"96-562","title":"Level II scour analysis for Bridge 28 (MNTGTH00190028) on Town Highway 19, crossing Wade Brook, Montgomery, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nMNTGTH00190028 on town highway 19 crossing Wade Brook, Montgomery, 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 Vermont Agency of Transportation (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 Green Mountain physiographic province of north-central Vermont in the \ntown of Montgomery. The 6.51-mi2\n drainage area is in a predominantly rural and forested\nbasin. In the vicinity of the study site, the banks have dense woody vegetation coverage.
\nIn the study area, Wade Brook has an incised, sinuous channel with a slope of \napproximately 0.0253 ft/ft, an average channel top width of 58 ft and an average channel \ndepth of 4 ft. The predominant channel bed material is gravel and cobbles (D50 is 81.8 mm \nor 0.269 ft). The geomorphic assessment at the time of the Level I and Level II site visit on \nNovember 9, 1994, indicated that the reach was stable.
\nThe town highway 19 crossing of Wade Brook is a 24-ft-wide corrugated steel, multi-plate \npipe-arch (Vermont Agency of Transportation, written communication, August 3, 1994). \nThe culvert is supported by vertical, concrete abutments with wingwalls. The channel is \nskewed approximately 30 degrees to the opening while the opening-skew-to-roadway is 26 \ndegrees.
\nThere was no localized scour evident during the Level I assessment. The scour protection \nmeasures at the site were type-2 stone fill (less than 36 inches diameter) on all of the \nroadway embankments, the upstream left bank, and each wingwall. 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, 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 0.5 to 1.0 ft. The worst-case \ncontraction scour occurred at the 500-year discharge. Abutment scour ranged from 8.6 to \n16.1 ft. The 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, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr96562","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Boehmler, E.M., and Hammond, R.E., 1996, Level II scour analysis for Bridge 28 (MNTGTH00190028) on Town Highway 19, crossing Wade Brook, Montgomery, Vermont: U.S. Geological Survey Open-File Report 96-562, iv, 47 p., https://doi.org/10.3133/ofr96562.","productDescription":"iv, 47 p.","numberOfPages":"52","costCenters":[],"links":[{"id":179260,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96562.PNG"},{"id":279337,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0562/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Montgomery","otherGeospatial":"Wade Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.75,43.5 ], [ -72.75,43.625 ], [ -72.625,43.625 ], [ -72.625,43.5 ], [ -72.75,43.5 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b19e4b07f02db6a7f93","contributors":{"authors":[{"text":"Boehmler, Erick M.","contributorId":96303,"corporation":false,"usgs":true,"family":"Boehmler","given":"Erick","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":240331,"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":240330,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49827,"text":"ofr96561 - 1996 - Level II scour analysis for Bridge 4 (MNTGTH00020004) on Town Highway 2, crossing Wade Brook, Montgomery, Vermont","interactions":[],"lastModifiedDate":"2013-12-10T13:45:03","indexId":"ofr96561","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":"96-561","title":"Level II scour analysis for Bridge 4 (MNTGTH00020004) on Town Highway 2, crossing Wade Brook, Montgomery, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nMNTGTH00020004 on town highway 2 crossing Wade Brook, Montgomery, 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 Green Mountain physiographic province of north-central Vermont in the \ntown of Montgomery. The 1.68-mi2\n drainage area is in a predominantly rural and forested\nbasin. In the vicinity of the study site, the banks have woody vegetation coverage.
\nIn the study area, Wade Brook has an incised, sinuous channel with a slope of \napproximately 0.0454 ft/ft, an average channel top width of 30 ft and an average channel \ndepth of 2 ft. The predominant channel bed materials are gravel and cobbles (D50 is 77.7 \nmm or 0.255 ft). The geomorphic assessment at the time of the Level I and Level II site visit \non November 8, 1994, indicated that the reach was degraded. There were no scour holes \nobserved during the Level I assessment. However, general streambed lowering was evident \nas both abutments were undermined equally with no localized scour on one abutment over \nthe other.
\nThe town highway 2 crossing of Wade Brook is a 23-ft-long, two-lane bridge consisting of \none 20-foot concrete slab span (Vermont Agency of Transportation, written \ncommunication, August 3, 1994). The bridge is supported by vertical, concrete abutments \nwith wingwalls. The channel is skewed approximately 30 degrees to the opening while the \ncomputed opening-skew-to-roadway is 25 degrees.
\nThe scour protection measures at the site were type-1 stone fill (less than 12 inches \ndiameter) on the upstream right wingwall and all road approach embankments, type-2 stone \nfill (less than 36 inches diameter) on the left abutment, and a “laid-up” stone wall at the \nupstream end of the upstream left wingwall and in front of the upstream left bank. \nAdditional details describing conditions at the site are included in the Level II Summary \nand Appendices D and E.
\nScour depths and rock rip-rap sizes were computed using the general guidelines described \nin Hydraulic Engineering Circular 18 (Richardson and others, 1995).\nTotal scour at a highway crossing is comprised of three components: 1) long-term \nstreambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction \nin flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and \nabutments). Total scour is the sum of the three components. Equations are available to \ncompute depths for contraction and local scour and a summary of the results of these \ncomputations follows.
\nContraction scour for all modelled flows was 0.1 ft. The worst-case contraction scour \noccurred at the 100-year and 500-year discharges. Abutment scour ranged from 3.9 to 5.2 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, 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/ofr96561","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Boehmler, E.M., 1996, Level II scour analysis for Bridge 4 (MNTGTH00020004) on Town Highway 2, crossing Wade Brook, Montgomery, Vermont: U.S. Geological Survey Open-File Report 96-561, iv, 48 p., https://doi.org/10.3133/ofr96561.","productDescription":"iv, 48 p.","numberOfPages":"53","costCenters":[],"links":[{"id":179259,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96561.PNG"},{"id":279338,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0561/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Montgomergy","otherGeospatial":"Wade Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.75,43.5 ], [ -72.75,43.625 ], [ -72.625,43.625 ], [ -72.625,43.5 ], [ -72.75,43.5 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a6220","contributors":{"authors":[{"text":"Boehmler, Erick M.","contributorId":96303,"corporation":false,"usgs":true,"family":"Boehmler","given":"Erick","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":240329,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":49826,"text":"ofr96409 - 1996 - Level II scour analysis for Bridge 32 (BRNATH00470032) on Town Highway 47, crossing Locust Creek, Barnard, Vermont","interactions":[{"subject":{"id":49826,"text":"ofr96409 - 1996 - Level II scour analysis for Bridge 32 (BRNATH00470032) on Town Highway 47, crossing Locust Creek, Barnard, Vermont","indexId":"ofr96409","publicationYear":"1996","noYear":false,"title":"Level II scour analysis for Bridge 32 (BRNATH00470032) on Town Highway 47, crossing Locust Creek, Barnard, Vermont"},"predicate":"SUPERSEDED_BY","object":{"id":50492,"text":"ofr2002150 - 2002 - Revised Protocols for Sampling Algal, Invertebrate, and Fish Communities as Part of the National Water-Quality Assessment Program","indexId":"ofr2002150","publicationYear":"2002","noYear":false,"title":"Revised Protocols for Sampling Algal, Invertebrate, and Fish Communities as Part of the National Water-Quality Assessment Program"},"id":1}],"supersededBy":{"id":50492,"text":"ofr2002150 - 2002 - Revised Protocols for Sampling Algal, Invertebrate, and Fish Communities as Part of the National Water-Quality Assessment Program","indexId":"ofr2002150","publicationYear":"2002","noYear":false,"title":"Revised Protocols for Sampling Algal, Invertebrate, and Fish Communities as Part of the National Water-Quality Assessment Program"},"lastModifiedDate":"2013-12-10T13:49:00","indexId":"ofr96409","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":"96-409","title":"Level II scour analysis for Bridge 32 (BRNATH00470032) on Town Highway 47, crossing Locust Creek, Barnard, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nBRNATH00470032 on town highway 47 crossing Locust Creek, Barnard, Vermont \n(figures 1–8). A Level II study is a basic engineering analysis of the site, including a \nquantitative analysis of stream stability and scour (U.S. Department of Transportation, \n1993). Results of a Level I scour investigation also are included in Appendix E of this \nreport. A Level I investigation provides a qualitative geomorphic characterization of the \nstudy site. Information on the bridge, gleaned from Vermont Agency of Transportation \n(VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is \nfound in Appendix D.
\nThe site is in the Green Mountain section of the New England physiographic province of \ncentral Vermont in the town of Barnard. The 6.26-mi2\n drainage area is in a predominantly \nrural and forested basin. In the vicinity of the study site, the banks have dense woody \nvegetation coverage except for the upstream right bank, which is grass and brush covered.
\nIn the study area, Locust Creek has an incised, sinuous channel with a slope of \napproximately 0.029 ft/ft, an average channel top width of 44 ft., and an average channel \ndepth of 5 ft. The predominant channel bed material is gravel and cobbles (D50 is 91.7 mm \nor 0.301 ft). The geomorphic assessment at the time of the Level I and Level II site visit on \nOctober 12, 1994, indicated that the reach was stable.
\nThe town highway 47 crossing of Locust Creek is a 28-ft-long, one-lane bridge consisting \nof one 25-foot span concrete slab superstructure (Vermont Agency of Transportation, \nwritten commun., August 23, 1994). The bridge is supported by vertical, concrete\nabutments with concrete wingwalls. The channel is skewed approximately 10 degrees to the \nopening while the opening-skew-to-roadway is 35 degrees.
\nThe scour protection measures at the site were type-2 stone fill (less than 36 inches \ndiameter) on the banks upstream, the upstream wingwalls, the downstream right wingwall, \nand the downstream right bank. The downstream left wingwall and left bank are protected \nwith type-3 stone fill (less than 48 inches diameter). 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 \nstreambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction \nin flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and \nabutments). Total scour is the sum of the three components. Equations are available to \ncompute depths for contraction and local scour and a summary of these computed results \nfollow.
\nContraction scour for all modelled flows ranged from 1.4 to 2.2 feet. The worst-case \ncontraction scour occurred at the 500-year discharge. Abutment scour ranged from 10.3 to \n15.0 feet. 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 depths, are \npresented in tables 1 and 2. A cross-section of the scour computed 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. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr96409","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Adminitration","usgsCitation":"Boehmler, E.M., 1996, Level II scour analysis for Bridge 32 (BRNATH00470032) on Town Highway 47, crossing Locust Creek, Barnard, Vermont: U.S. Geological Survey Open-File Report 96-409, iv, 48 p., https://doi.org/10.3133/ofr96409.","productDescription":"iv, 48 p.","numberOfPages":"53","costCenters":[],"links":[{"id":179258,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96409.PNG"},{"id":279339,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0409/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Barnard","otherGeospatial":"Locust Creek","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.75,43.625 ], [ -72.75,43.75 ], [ 72.625,43.75 ], [ 72.625,43.625 ], [ -72.75,43.625 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4a7fe4b07f02db6486bf","contributors":{"authors":[{"text":"Boehmler, Erick M.","contributorId":96303,"corporation":false,"usgs":true,"family":"Boehmler","given":"Erick","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":240328,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":49799,"text":"ofr96244 - 1996 - Level II scour analysis for Bridge 45a (BRIDUS00040045a) on U.S. Route 4, crossing Ottauquechee River, Bridgewater, Vermont","interactions":[],"lastModifiedDate":"2013-12-11T10:41:02","indexId":"ofr96244","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":"96-244","title":"Level II scour analysis for Bridge 45a (BRIDUS00040045a) on U.S. Route 4, crossing Ottauquechee River, Bridgewater, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nBRIDUS00040045a on U.S.. Route 4 crossing the Ottauquechee River, 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 province of central Vermont in the town of \nBridgewater. The 72.1-mi2\n drainage area is in a predominantly rural and forested basin. In \nthe vicinity of the study site, the overbank areas are lawn or pasture with a few residences. \nThe immediate channel banks have moderately dense woody vegetation.
\nIn the study area, the Ottauquechee River has a sinuous channel with a slope of \napproximately 0.01 ft/ft, an average channel top width of 81 ft and an average channel \ndepth of 3 ft. The predominant channel bed materials are gravel and cobble (D50 is 54.9 mm \nor 0.180 ft). The geomorphic assessment at the time of the Level I and Level II site visit on \nOctober 26, 1994, indicated that the reach was stable.
\nThe U.S. Route 4 crossing of the Ottauquechee Riveris a 172-ft-long, two-lane bridge \nconsisting of three steel-beam spans supported by spill-through abutments and two concrete \npiers (Vermont Agency of Transportation, written commun., August 25, 1994). The \nabutment and road approaches are protected by type-2 stone fill (less than 36 inches \ndiameter). The North Branch of the Ottauquechee River joins the Ottauquechee River \napproximately 200 feet upstream of the bridge on the main branch’s left bank. The channel \napproach to the bridge has a mild bend with the bridge skewed 15 degrees to flow; the \nopening-skew-to-roadway is 30 degrees. Additional details describing conditions at the site \nare 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 3.1 to 4.0 ft. with the worst-case \ncontraction scour occurring at the 500-year and incipient road-overflow discharges. \nAbutment scour ranged from 9.3 to 15.2 ft. The worst-case abutment scour also occurred at \nthe 500-year discharge. Pier scour ranged from 11.4 to 12.4 ft. with the worst-case scenario \noccurring at the incipient roadway overflow discharge. The incipient roadway overflow \ndischarge was between the 100- and 500-year discharges. Additional information on scour \ndepths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. \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, 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/ofr96244","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Olson, S.A., 1996, Level II scour analysis for Bridge 45a (BRIDUS00040045a) on U.S. Route 4, crossing Ottauquechee River, Bridgewater, Vermont: U.S. Geological Survey Open-File Report 96-244, iv, 30 p., https://doi.org/10.3133/ofr96244.","productDescription":"iv, 30 p.","numberOfPages":"35","costCenters":[],"links":[{"id":179257,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96244.GIF"},{"id":279382,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0244/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Bridgewater","otherGeospatial":"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":"4f4e4b17e4b07f02db6a60e3","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":240279,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"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":49825,"text":"ofr96408 - 1996 - Level II scour analysis for Bridge 1 (BLOOTH00020001) on Town Highway 2, crossing Mill Brook, Bloomfield, Vermont","interactions":[],"lastModifiedDate":"2013-12-10T14:17:04","indexId":"ofr96408","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":"96-408","title":"Level II scour analysis for Bridge 1 (BLOOTH00020001) on Town Highway 2, crossing Mill Brook, Bloomfield, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nBLOOTH00020001 on town highway 2 crossing Mill Brook, Bloomfield, Vermont (figures \n1–8). A Level II study is a basic engineering analysis of the site, including a quantitative \nanalysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of \na Level I scour investigation also are included in Appendix E of this report. A Level I \ninvestigation provides a qualitative geomorphic characterization of the study site. \nInformation on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) \nfiles, was compiled prior to conducting Level I and Level II analyses and is found in \nAppendix D.
\nThe site is in the White Mountain section of the New England Upland physiographic \nprovince of north-east Vermont in the town of Bloomfield. The 4.85-mi2\n drainage area is in \na predominantly rural and forested basin. In the vicinity of the study site, the banks have \ndense woody vegetation coverage.
\nIn the study area, Mill Brook has an incised, sinuous channel with a slope of approximately \n0.03 ft/ft, an average channel top width of 28 ft and an average channel depth of 4 ft. The \npredominant channel bed materials are gravel and cobbles (D50 is 57.3 mm or 0.188 ft). The \ngeomorphic assessment at the time of the Level I and Level II site visit on July 6, 1995,\nindicated that the reach was stable.
\nThe town highway 2 crossing of Mill Brook is a 26-ft-long, one-lane bridge consisting of \none 24-foot concrete span (Vermont Agency of Transportation, written commun., August 4, \n1994). The bridge is supported by vertical, concrete abutments with wingwalls. The channel \nis skewed approximately 30 degrees to the opening while the opening-skew-to-roadway is \n10 degrees.
\nNo scour was observed along the channel or at the bridge during the Level I assessment. \nType-2 stone fill (less than 24 inches diameter) was noted as present along all wingwalls.\nAdditional details describing conditions at the site are included in the Level II Summary \nand Appendices D and E.
\nScour depths and rock rip-rap sizes were computed using the general guidelines described \nin Hydraulic Engineering Circular 18 (Richardson and others, 1995). Total scour at a \nhighway crossing is comprised of three components: 1) long-term aggradation or \ndegradation; 2) contraction scour (due to reduction in flow area caused by a bridge) and; 3) \nlocal scour (caused by accelerated flow around piers and abutments). Total scour is the sum \nof the three components. Equations are available to compute scour depths for contraction \nand local scour and a summary of the results follows.
\nContraction scour for all modelled flows ranged from 0 to 1.0 feet and the worst-case \ncontraction scour occurred at the incipient overtopping discharge. Abutment scour ranged \nfrom 7.3 to 10.1 feet and the worst-case abutment scour occurred at the 500-year discharge. \nAdditional information on scour depths and depths to armoring are included in the section \ntitled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, \nare presented in tables 1 and 2. A cross-section of the scour computed at the bridge is \npresented in figure 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, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr96408","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Ayotte, J., and Medalie, L., 1996, Level II scour analysis for Bridge 1 (BLOOTH00020001) on Town Highway 2, crossing Mill Brook, Bloomfield, Vermont: U.S. Geological Survey Open-File Report 96-408, iv, 53 p., https://doi.org/10.3133/ofr96408.","productDescription":"iv, 53 p.","numberOfPages":"58","costCenters":[],"links":[{"id":178736,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96408.PNG"},{"id":279340,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0408/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Bloomfield","otherGeospatial":"Mill Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -71.625,44.75 ], [ -71.625,44.875 ], [ -71.5,44.875 ], [ -71.5,44.75 ], [ -71.625,44.75 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b1ae4b07f02db6a8495","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":240326,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Medalie, Laura 0000-0002-2440-2149 lmedalie@usgs.gov","orcid":"https://orcid.org/0000-0002-2440-2149","contributorId":3657,"corporation":false,"usgs":true,"family":"Medalie","given":"Laura","email":"lmedalie@usgs.gov","affiliations":[{"id":466,"text":"New England Water Science Center","active":true,"usgs":true}],"preferred":true,"id":240327,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"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":49802,"text":"ofr96304 - 1996 - Level II scour analysis for Bridge 30 (BRIDTH00330030) on Town Highway 33, crossing Dailey Hollow Branch, Bridgewater, Vermont","interactions":[],"lastModifiedDate":"2013-12-11T10:20:51","indexId":"ofr96304","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":"96-304","title":"Level II scour analysis for Bridge 30 (BRIDTH00330030) on Town Highway 33, crossing Dailey Hollow Branch, Bridgewater, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nBRIDTH00330030 on town highway 33 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 province of central Vermont in the town of \nBridgewater. The 7.51-mi2\n drainage area is in a predominantly rural and forested basin. In \nthe vicinity of the study site, the surface cover is forest.
\nIn the study area, Dailey Hollow Branch has an incised, sinuous channel with a slope of \napproximately 0.013 ft/ft, an average channel top width of 45 ft and an average channel \ndepth of 5 ft. The channel bed material ranges from sand to boulder with a median grain \nsize (D50) of 60.7 mm (0.199 ft). The geomorphic assessment at the time of the Level I and \nLevel II site visit on November 1, 1994, indicated that the reach was stable.
\nThe town highway 33 crossing of Dailey Hollow Branch is a 31-ft-long, one-lane bridge \nconsisting of one 25-foot steel-beam span with a timber deck (Vermont Agency of \nTransportation, written communication, August 25, 1994). The bridge is supported by \nvertical, concrete abutments with wingwalls. The channel is skewed approximately 20 \ndegrees to the opening while the opening-skew-to-roadway is 0 degrees. Type-2 stone-fill \n(less than 36 inches diameter) protection was found at all four wingwalls. 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). 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 0.5 to 3.1 ft. The worst-case \ncontraction scour occurred at the incipient-roadway-overtopping discharge, which is \nbetween the 100- and 500-year discharge. Abutment scour ranged from 6.9 to 14.6 ft. with \nthe worst-case scenario also occurring at the incipient-roadway-overtopping discharge. \nAdditional information on scour depths and depths to armoring are included in the section \ntitled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, \nare presented in tables 1 and 2. A cross-section of the scour computed at the bridge is \npresented in figure 8. Scour depths were calculated assuming an infinite depth of erosive \nmaterial and a homogeneous particle-size distribution.
\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/ofr96304","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 30 (BRIDTH00330030) on Town Highway 33, crossing Dailey Hollow Branch, Bridgewater, Vermont: U.S. Geological Survey Open-File Report 96-304, iv, 30 p., https://doi.org/10.3133/ofr96304.","productDescription":"iv, 30 p.","numberOfPages":"35","costCenters":[],"links":[{"id":179331,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96304.GIF"},{"id":279379,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0304/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 ], [ -72.75,43.75 ], [ -72.625,43.75 ], [ -72.625,43.5 ], [ -72.75,43.5 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b19e4b07f02db6a7edc","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":240284,"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":240285,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49803,"text":"ofr96305 - 1996 - Level II scour analysis for Bridge 35 (BRIDTH00050035) on Town Highway 05, crossing the North Branch Ottauquechee River, Bridgewater, Vermont","interactions":[],"lastModifiedDate":"2013-12-11T10:21:23","indexId":"ofr96305","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":"96-305","title":"Level II scour analysis for Bridge 35 (BRIDTH00050035) on Town Highway 05, crossing the North Branch Ottauquechee River, Bridgewater, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nBRIDTH00050035 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. The 6.70-mi2\ndrainage area is in a predominantly rural and forested basin. In the vicinity of the study site, \nsurface cover is predominately forest. Town Highway 5 runs parallel to the upstream left \nand downstream right banks.
\nIn the study area, the North Branch Ottauquechee River has an incised, sinuous channel \nwith a slope of approximately 0.015 ft/ft, an average channel top width of 33 ft and an \naverage channel depth of 3 ft. The predominant channel bed materials are gravel and cobble \n(D50 is 74.8 mm or 0.245 ft). The geomorphic assessment at the time of the Level I and \nLevel II site visit on November 2, 1994, indicated that the reach was stable.
\nThe town highway 5 crossing of the North Branch Ottauquechee River is a 30-ft-long, one-lane bridge consisting of one 24-foot steel-beam span with a timber deck (Vermont Agency \nof Transportation, written communication, August 25, 1994). The bridge is supported by a \ntimber cribwork abutment on the right and stone wall abutment on the left. A scour hole 3 ft \ndeeper than the mean thalweg depth was observed along the left abutment during the Level \nI assessment. The channel is skewed approximately 30 degrees to the opening while the \nopening-skew-to-roadway is 25 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). 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 0.7 to 0.8 ft. The worst-case \ncontraction scour occurred at the incipient-roadway-overtopping discharge and at the 100-\nyear discharge. Abutment scour ranged from 8.0 to 15.1 ft. with the worst-case abutment \nscour occurring 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/ofr96305","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 35 (BRIDTH00050035) on Town Highway 05, crossing the North Branch Ottauquechee River, Bridgewater, Vermont: U.S. Geological Survey Open-File Report 96-305, iv, 30 p., https://doi.org/10.3133/ofr96305.","productDescription":"iv, 30 p.","numberOfPages":"35","costCenters":[],"links":[{"id":179402,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96305.GIF"},{"id":279378,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0305/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":"4f4e4b17e4b07f02db6a648d","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":240287,"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":240286,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49804,"text":"ofr96306 - 1996 - Level II scour analysis for Bridge 35 (BRNATH00680035) on Town Highway 68, crossing Locust Creek, Barnard, Vermont","interactions":[],"lastModifiedDate":"2013-12-11T09:51:51","indexId":"ofr96306","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":"96-306","title":"Level II scour analysis for Bridge 35 (BRNATH00680035) on Town Highway 68, crossing Locust Creek, Barnard, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nBRNATH00680035 on town highway 68 crossing Locust Creek, Barnard, Vermont \n(figures 1–8). A Level II study is a basic engineering analysis of the site, including a \nquantitative analysis of stream stability and scour (U.S. Department of Transportation, \n1993). 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 \nBarnard. The 24.1-mi2\n drainage area is in a predominantly rural and forested basin. In the \nvicinity of the study site, the banks have woody vegetation coverage.
\nIn the study area, Locust Creek has an incised sinuous channel with a slope of \napproximately 0.0133 ft/ft, an average channel top width of 58 ft and an average channel \ndepth of 5 ft. The predominant channel bed material is cobble (D50 is 135 mm or 0.443 ft). \nThe geomorphic assessment at the time of the Level I and Level II site visits on September \n21 and 27, respectively, with a check on December 15, 1994, indicated that the reach was \nstable.
\nThe town highway 68 crossing of Locust Creek is a 30-ft-long, one-lane bridge consisting \nof one 28-foot concrete slab type superstructure (Vermont Agency of Transportation, \nwritten commun., August 23, 1994). The bridge is supported by vertical, concrete\nabutments with wingwalls. The channel is not skewed to the opening and the opening-skew-to-roadway is zero degrees.
\nA scour hole 0.5 ft deeper than the mean thalweg depth was observed along the right \nabutment and downstream right wingwall during the Level I assessment. The only scour \nprotection measure in place at the site was type-2 stone fill (less than 36 inches diameter) at \nthe left abutment and wingwalls except the downstream right wingwall. Additional details \ndescribing conditions at the site are included in the Level II Summary and Appendices D.
\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 0.0 to 3.4 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 11.5 to 25.7 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, 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.\nand E.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr96306","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Ivanoff, M.A., and Weber, M.A., 1996, Level II scour analysis for Bridge 35 (BRNATH00680035) on Town Highway 68, crossing Locust Creek, Barnard, Vermont: U.S. Geological Survey Open-File Report 96-306, iv, 30 p., https://doi.org/10.3133/ofr96306.","productDescription":"iv, 30 p.","numberOfPages":"35","costCenters":[],"links":[{"id":179403,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96306.GIF"},{"id":279377,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0306/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Barnard","otherGeospatial":"Locust Creek","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.75,43.75 ], [ -72.75,43.875 ], [ -72.625,43.875 ], [ -72.625,43.75 ], [ -72.75,43.75 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a64ab","contributors":{"authors":[{"text":"Ivanoff, Michael A.","contributorId":27105,"corporation":false,"usgs":true,"family":"Ivanoff","given":"Michael","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":240288,"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":240289,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"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":49806,"text":"ofr96308 - 1996 - Level II scour analysis for Bridge 54 (RANDTH00BR0054) on Brook Street, crossing Thayer Brook, Randolph, Vermont","interactions":[],"lastModifiedDate":"2013-12-11T09:22:00","indexId":"ofr96308","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":"96-308","title":"Level II scour analysis for Bridge 54 (RANDTH00BR0054) on Brook Street, crossing Thayer Brook, Randolph, Vermont","docAbstract":"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}]}} ]}