{"pageNumber":"418","pageRowStart":"10425","pageSize":"25","recordCount":36991,"records":[{"id":49840,"text":"ofr96583 - 1996 - Level II scour analysis for Bridge 13 (POMFTH00020013) on Town Highway 2, crossing Barnard Brook, Pomfret, Vermont","interactions":[],"lastModifiedDate":"2013-12-05T15:30:34","indexId":"ofr96583","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":"96-583","title":"Level II scour analysis for Bridge 13 (POMFTH00020013) on Town Highway 2, crossing Barnard Brook, Pomfret, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nPOMFTH00020013 on town highway 2 crossing Barnard Brook, Pomfret, 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 study 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 can be found in \nAppendix D.\nThe site is in the New England Upland section of the New England physiographic province \nof east-central Vermont in the town of Pomfret. The 7.98-mi2\n drainage area is in a \npredominantly rural and forested basin. In the vicinity of the study site, the surface cover is \nprimarily field grasses with some brush on the immediate banks.\nIn the study area, Barnard Brook has an incised, sinuous channel with a slope of \napproximately 0.006 ft/ft, an average channel top width of 32 ft and an average channel \ndepth of 4 ft. The predominant channel bed materials are gravel and cobbles with a median \ngrain size (D50) of 51.0 mm (0.167 ft). The geomorphic assessment at the time of the Level \nI and Level II site visit on September 15, 1994, indicated that the reach was stable.\nThe town highway 2 crossing of Barnard Brook is a 23-ft-long, two-lane bridge consisting \nof one 20-foot concrete span (Vermont Agency of Transportation, written communication, \nAugust 22, 1994). The bridge is supported by vertical, concrete abutments with wingwalls. \nThe channel is skewed approximately 30 degrees to the opening while the opening-skew-toroadway is 0 degrees. \nScour, 2.5 ft deeper than the mean thalweg depth, was observed along the left abutment \nduring the Level I assessment. The only scour protection measure at the site was type-2 \nstone fill (less than 36 inches diameter) along the base and upstream of the upstream left \nwingwall. Additional details describing conditions at the site are included in the Level II \nSummary and Appendices D and E.\nScour depths and rock rip-rap sizes were computed using the general guidelines described \nin Hydraulic Engineering Circular 18 (Richardson and others, 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 1.5 ft. The worst-case \ncontraction scour occurred at the 100-year discharge. Abutment scour ranged from 7.2 to \n12.6 ft. The worst-case abutment scour occurred at the 500-year discharge. Additional \ninformation on scour depths and depths to armoring are included in the section titled “Scour \nResults”. Scoured-streambed elevations, based on the calculated scour depths, are presented \nin tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure \n8. Scour depths were calculated assuming an infinite depth of erosive material and a \nhomogeneous particle-size distribution. \nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.","language":"English","publisher":"U.S. Geological Survey","doi":"10.3133/ofr96583","collaboration":"Prepared cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Ivanoff, M.A., 1996, Level II scour analysis for Bridge 13 (POMFTH00020013) on Town Highway 2, crossing Barnard Brook, Pomfret, Vermont: U.S. Geological Survey Open-File Report 96-583, iv, 50 p., https://doi.org/10.3133/ofr96583.","productDescription":"iv, 50 p.","numberOfPages":"55","costCenters":[],"links":[{"id":162640,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96583.PNG"},{"id":279286,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0583/report.pdf"}],"country":"United States","state":"Vermont","city":"Pomfret","otherGeospatial":"Barnard Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.588101,43.63863 ], [ -72.588101,43.758075 ], [ -72.426329,43.758075 ], [ -72.426329,43.63863 ], [ -72.588101,43.63863 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b1ae4b07f02db6a832a","contributors":{"authors":[{"text":"Ivanoff, Michael A.","contributorId":27105,"corporation":false,"usgs":true,"family":"Ivanoff","given":"Michael","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":240348,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":49841,"text":"ofr96584 - 1996 - Level II scour analysis for Bridge 36 (RICHVT01050036) on State Route 105, crossing Stanhope Brook, Richford, Vermont","interactions":[],"lastModifiedDate":"2013-12-05T15:21:09","indexId":"ofr96584","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":"96-584","title":"Level II scour analysis for Bridge 36 (RICHVT01050036) on State Route 105, crossing Stanhope Brook, Richford, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nRICHVT01050036 on State Route 105 crossing Stanhope Brook, Richford, Vermont \n(figures 1–8). A Level II study is a basic engineering analysis of the site, including a \nquantitative analysis of stream stability and scour (U.S. Department of Transportation, \n1993). Results of a Level I scour investigation also are included in Appendix E of this \nreport. A Level I investigation provides a qualitative geomorphic characterization of the \nstudy site. Information on the bridge, gleaned from Vermont Agency of Transportation \n(VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is \nfound in Appendix D.\nThe site is in the Green Mountain section of the New England physiographic province in \nnorth-central Vermont. The 7.03-mi2\n drainage area is in a predominantly rural and forested\nbasin. In the vicinity of the study site, the surface cover is short grass except for the \nupstream left overbank area which is forested.\nIn the study area, Stanhope Brook has a steep, sinuous channel with a slope of \napproximately 0.03 ft/ft, an average channel top width of 47 ft and an average channel \ndepth of 5 ft. The predominant channel bed material is cobble with a median grain size \n(D50) of 132 mm (0.432 ft). The geomorphic assessment at the time of the Level I and Level \nII site visit on June 28, 1995, indicated that the reach was laterally unstable.\nThe State Route 105 crossing of Stanhope Brook is a 42-ft-long, two-lane bridge consisting \nof one 38-foot concrete T-beam span (Vermont Agency of Transportation, written \ncommunication, March 8, 1995). The bridge is supported by vertical, concrete abutments \nwith wingwalls. The channel is skewed approximately 15 degrees to the opening while the \nopening-skew-to-roadway is 20 degrees. \nA scour hole 0.5 ft deeper than the mean thalweg depth was observed along the downstream \nend of the right abutment wall during the Level I assessment. The scour protection measures \nat this site were type-2 stone fill (less than 36 inches diameter) along the entire lengths of \nthe upstream wingwalls, at the corner of the downstream left abutment and downstream left\nwingwall and the downstream end of the downstream right 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 0.0 to 0.3 ft. The worst-case \ncontraction scour occurred at the 500-year discharge. Abutment scour ranged from 6.6 to \n9.4 ft. The worst-case abutment scour occurred at the 500-year discharge. Additional \ninformation on scour depths and depths to armoring are included in the section titled “Scour \nResults”. Scoured-streambed elevations, based on the calculated scour depths, are presented \nin tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure \n8. Scour depths were calculated assuming an infinite depth of erosive material and a \nhomogeneous particle-size distribution. \nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.","language":"English","publisher":"U.S. Geological Survey","doi":"10.3133/ofr96584","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Boehmler, E.M., and Ivanoff, M.A., 1996, Level II scour analysis for Bridge 36 (RICHVT01050036) on State Route 105, crossing Stanhope Brook, Richford, Vermont: U.S. Geological Survey Open-File Report 96-584, iv, 47 p., https://doi.org/10.3133/ofr96584.","productDescription":"iv, 47 p.","numberOfPages":"52","costCenters":[],"links":[{"id":162641,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96584.PNG"},{"id":279285,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0584/report.pdf"}],"country":"United States","state":"Vermont","city":"Richford","otherGeospatial":"Stanhope Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.702647,44.921965 ], [ -72.702647,45.015684 ], [ -72.535709,45.015684 ], [ -72.535709,44.921965 ], [ -72.702647,44.921965 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a6458","contributors":{"authors":[{"text":"Boehmler, Erick M.","contributorId":96303,"corporation":false,"usgs":true,"family":"Boehmler","given":"Erick","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":240350,"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":240349,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49842,"text":"ofr96585 - 1996 - Level II scour analysis for Bridge 46 (ENOSVT01080046) on State Route 108, crossing an Unnamed \"The Branch\" Tributary, Enosburg, Vermont","interactions":[],"lastModifiedDate":"2013-12-05T15:15:58","indexId":"ofr96585","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":"96-585","title":"Level II scour analysis for Bridge 46 (ENOSVT01080046) on State Route 108, crossing an Unnamed \"The Branch\" Tributary, Enosburg, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nENOSVT01080046 on State Route 108 crossing an unnamed \"The Branch\" tributary, \nEnosburg, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the \nsite, including a quantitative analysis of stream stability and scour (U.S. Department of \nTransportation, 1993). Results of a Level I scour investigation also are included in \nAppendix E of this report. A Level I investigation provides a qualitative geomorphic \ncharacterization of the study site. Information on the bridge, gleaned from Vermont Agency \nof Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II \nanalyses and is found in Appendix D.\nThe site is in the Green Mountain section of the New England physiographic province in \nnorth-central Vermont. The 1.55-mi2\n drainage area is in a predominantly rural, pasture and \nforested basin. In the vicinity of the study site, the surface cover is pasture.\nIn the study area, this unnamed \"The Branch\" tributary has an incised, sinuous channel with \na slope of approximately 0.03 ft/ft, an average channel top width of 45 ft and an average \nchannel depth of 3 ft. The predominant channel bed material is gravel and cobbles with a \nmedian grain size (D50) of 42.4 mm (0.139 ft). The geomorphic assessment at the time of \nthe Level I and Level II site visit on June 29, 1995, indicated that the reach was laterally \nunstable. Block failure slumping of bank material was evident at an upstream cut-bank and \nanother minor cut-bank was noted downstream.\nThe State Route 108 crossing of this unnamed \"The Branch\" tributary is a 25-ft-long, twolane bridge consisting of one 22-foot concrete span (Vermont Agency of Transportation, \nwritten communication, March 8, 1995). The bridge is supported by vertical, concrete\nabutments with wingwalls. The channel is skewed approximately 10 degrees to the opening \nwhile the opening-skew-to-roadway is zero degrees. \nThe only scour protection measure at the site was type-2 stone fill (less than 36 inches \ndiameter) at the downstream end of the downstream left 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 0.3 to 0.5 ft. The worst-case \ncontraction scour occurred at the 500-year discharge. Abutment scour ranged from 4.0 to \n8.0 ft. The worst-case abutment scour occurred at the 500-year discharge. Additional \ninformation on scour depths and depths to armoring are included in the section titled “Scour \nResults”. Scoured-streambed elevations, based on the calculated scour depths, are presented \nin tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure \n8. Scour depths were calculated assuming an infinite depth of erosive material and a \nhomogeneous particle-size distribution. \nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.","language":"English","publisher":"U.S. Geological Survey","doi":"10.3133/ofr96585","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Boehmler, E.M., and Medalie, L., 1996, Level II scour analysis for Bridge 46 (ENOSVT01080046) on State Route 108, crossing an Unnamed \"The Branch\" Tributary, Enosburg, Vermont: U.S. Geological Survey Open-File Report 96-585, iv, 47 p., https://doi.org/10.3133/ofr96585.","productDescription":"iv, 47 p.","numberOfPages":"52","costCenters":[],"links":[{"id":162642,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96585.PNG"},{"id":279284,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0585/report.pdf"}],"country":"United States","state":"Vermont","city":"Enosburg","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.840964,44.836286 ], [ -72.840964,44.929092 ], [ -72.661234,44.929092 ], [ -72.661234,44.836286 ], [ -72.840964,44.836286 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a60d8","contributors":{"authors":[{"text":"Boehmler, Erick M.","contributorId":96303,"corporation":false,"usgs":true,"family":"Boehmler","given":"Erick","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":240352,"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":240351,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49843,"text":"ofr96586 - 1996 - Level II scour analysis for Bridge 94 (FERDVT01050094) on State Route 105, crossing the Nulhegan River, Ferdinand, Vermont","interactions":[],"lastModifiedDate":"2013-12-05T15:09:37","indexId":"ofr96586","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":"96-586","title":"Level II scour analysis for Bridge 94 (FERDVT01050094) on State Route 105, crossing the Nulhegan River, Ferdinand, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nFERDVT01050094 on State Route 105 crossing the Nulhegan River, Ferdinand, 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 White Mountain section of the New England physiographic province in \nnortheastern Vermont. The 38.4-mi2\n drainage area is in a predominantly rural and forested\nbasin. In the vicinity of the study site, the surface cover is grass and brush with wetlands \nimmediately adjacent to the stream channel.\nIn the study area, the Nulhegan River has a meandering channel with a slope of \napproximately 0.002 ft/ft, an average channel top width of 60 ft and an average channel \ndepth of 6 ft. The predominant channel bed material is sand with a median grain size (D50) \nof 0.465 mm (0.00153 ft). The geomorphic assessment at the time of the Level I and Level \nII site visit on July 5, 1995, indicated that the reach was laterally unstable.\nThe State Route 105 crossing of the Nulhegan Riveris a 44-ft-long, two-lane bridge \nconsisting of one 42-foot steel-beam span (Vermont Agency of Transportation, written \ncommunication, March 6, 1995). The bridge is supported by vertical, concrete abutments \nwith wingwalls. The channel is skewed approximately 10 degrees to the opening while the \nopening-skew-to-roadway is zero degrees. \nScour protection measures at the site were type-2 stone fill (less than 36 inches diameter) on \nthe upstream right bank, the upstream right wingwall, the right abutment, the downstream \nend of the left abutment and the downstream wingwalls. 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, 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 1.2 to 1.9 ft. The worst-case \ncontraction scour occurred at the 500-year discharge. Abutment scour ranged from 6.6 to \n11.0 ft. The worst-case abutment scour also occurred at the 500-year discharge. Total scour \ndepths computed for this site were not below the bottom of the footings, except for the 500-\nyear discharge model at the left abutment. Additional information on scour depths and \ndepths to armoring are included in the section titled “Scour Results”. Scoured-streambed \nelevations, based on the calculated scour depths, are presented in tables 1 and 2. A crosssection of the scour computed at the bridge is presented in figure 8. Scour depths were \ncalculated assuming an infinite depth of erosive material and a homogeneous particle-size \ndistribution. \nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.","language":"English","publisher":"U.S. Geological Survey","doi":"10.3133/ofr96586","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Boehmler, E.M., and Degnan, J.R., 1996, Level II scour analysis for Bridge 94 (FERDVT01050094) on State Route 105, crossing the Nulhegan River, Ferdinand, Vermont: U.S. Geological Survey Open-File Report 96-586, iv, 47 p., https://doi.org/10.3133/ofr96586.","productDescription":"iv, 47 p.","numberOfPages":"52","costCenters":[],"links":[{"id":162643,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96586.PNG"},{"id":279283,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0586/report.pdf"}],"country":"United States","state":"Vermont","city":"Ferdinand","otherGeospatial":"Nulhegan River","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -71.858382,44.626732 ], [ -71.858382,44.820132 ], [ -71.662301,44.820132 ], [ -71.662301,44.626732 ], [ -71.858382,44.626732 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b16e4b07f02db6a5597","contributors":{"authors":[{"text":"Boehmler, Erick M.","contributorId":96303,"corporation":false,"usgs":true,"family":"Boehmler","given":"Erick","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":240354,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Degnan, James R. 0000-0002-5665-9010 jrdegnan@usgs.gov","orcid":"https://orcid.org/0000-0002-5665-9010","contributorId":498,"corporation":false,"usgs":true,"family":"Degnan","given":"James","email":"jrdegnan@usgs.gov","middleInitial":"R.","affiliations":[{"id":466,"text":"New England Water Science Center","active":true,"usgs":true},{"id":405,"text":"NH/VT office of New England Water Science Center","active":true,"usgs":true}],"preferred":true,"id":240353,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49844,"text":"ofr96587 - 1996 - Level II scour analysis for Bridge 38 (RANDTH00640038) on Town Highway 64, crossing the Second Branch of the White River, Randolph, Vermont","interactions":[],"lastModifiedDate":"2013-12-05T15:04:29","indexId":"ofr96587","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":"96-587","title":"Level II scour analysis for Bridge 38 (RANDTH00640038) on Town Highway 64, crossing the Second Branch of the White River, Randolph, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nRANDTH00640038 on town highway 64 crossing the Second Branch of the White River, \nRandolph, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the \nsite, including a quantitative analysis of stream stability and scour (U.S. Department of \nTransportation, 1993). Results of a Level I scour investigation also are included in \nAppendix E of this report. A Level I investigation provides a qualitative geomorphic \ncharacterization of the study site. Information on the bridge, gleaned from Vermont Agency \nof Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II \nanalyses and is found in Appendix D.\nThe site is in the Green Mountain section of the New England physiographic province of \ncentral Vermont. The 46.5-mi2\n drainage area is in a predominantly rural and forested basin. \nIn the vicinity of the study site, the The upstream left bank is forested, the upstream right \nbank is covered primarily by brush, the surface cover is pasture on the downstream left and \nrow crops on the downstream right. \nIn the study area, the Second Branch of the White River has an incised, sinuous channel \nwith a slope of approximately 0.0015 ft/ft, an average channel top width of 71 ft and an \naverage channel depth of 8 ft. The predominant channel bed material is gravel with a \nmedian grain size (D50) of 32.0 mm (0.105 ft). The geomorphic assessment at the time of \nthe Level I site visits on August 10, 1994 and December 5, 1994 indicated that the reach \nwas laterally unstable.\nThe town highway 64 crossing of the Second Branch of the White Riveris a 43-ft-long, \none-lane covered bridge consisting of one 35-foot steel-beam span (Vermont Agency of \nTransportation, written communication, August 1, 1994). The bridge is supported by \nvertical, stone abutments with upstream wingwalls. The channel bends sharply at it’s \napproach to the bridge, however, at the bridge face, the channel is skewed approximately 0 \ndegrees to the opening. The opening-skew-to-roadway is also 0 degrees.\nA scour hole 2 ft deeper than the mean thalweg depth was observed upstream of the bridge \nalong the outside of the channel bend. Other scour problems at this site included \nundermining of the right abutment at it’s upstream and downstream ends. 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 1.7 to 2.6 ft. The worst-case \ncontraction scour occurred at the 500-year discharge. Abutment scour ranged from 7.2 to \n24.2 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","doi":"10.3133/ofr96587","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Olson, S.A., 1996, Level II scour analysis for Bridge 38 (RANDTH00640038) on Town Highway 64, crossing the Second Branch of the White River, Randolph, Vermont: U.S. Geological Survey Open-File Report 96-587, iv, 51 p., https://doi.org/10.3133/ofr96587.","productDescription":"iv, 51 p.","numberOfPages":"56","costCenters":[],"links":[{"id":162644,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96587.PNG"},{"id":279282,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0587/report.pdf"}],"country":"United States","state":"Vermont","city":"Randolph","otherGeospatial":"White River","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.703521,43.873348 ], [ -72.703521,44.000618 ], [ -72.509922,44.000618 ], [ -72.509922,43.873348 ], [ -72.703521,43.873348 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a628e","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":240355,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":49845,"text":"ofr96635 - 1996 - Level II scour analysis for Bridge 6 (RICHTH00030006) on Town Highway 3, crossing an unnamed tributary to the Missisquoi River, Richford, Vermont","interactions":[],"lastModifiedDate":"2013-12-05T14:57:41","indexId":"ofr96635","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":"96-635","title":"Level II scour analysis for Bridge 6 (RICHTH00030006) on Town Highway 3, crossing an unnamed tributary to the Missisquoi River, Richford, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nRICHTH00030006 on Town Highway 3 crossing an unnamed tributary to the Missisquoi \nRiver, Richford, Vermont (figures 1–8). A Level II study is a basic engineering analysis of \nthe site, including a quantitative analysis of stream stability and scour (U.S. Department of \nTransportation, 1993). Results of a Level I scour investigation also are included in \nAppendix E of this report. A Level I investigation provides a qualitative geomorphic \ncharacterization of the study site. Information on the bridge, gleaned from Vermont Agency \nof Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II \nanalyses and is found in Appendix D.\nThe site is in the Green Mountain section of the New England physiographic province of \nnorthern Vermont. The 4.5-mi2\n drainage area is in a predominantly rural basin. In the \nvicinity of the study site, the surface cover is pasture upstream and downstream of the \nbridge.\nIn the study area, the unnamed tributary to the Missisquoi River is a sinuous channel with a \nslope of approximately 0.008 ft/ft, an average channel top width of 39 ft and an average \nchannel depth of 2 ft. The channel slope was obtained from a topographic map (USGS, \n1986). The predominant channel bed material is gravel with a median grain size (D50) of \n26.2 mm (0.0861 ft). The geomorphic assessment at the time of the Level I and Level II site \nvisit on June 28, 1995, indicated that the reach was stable.\nThe Town Highway 3 crossing of an unnamed tributary to the Missisquoi River is a 26-ftlong, two-lane bridge consisting of one 24-foot concrete T-beam span (Vermont Agency of \nTransportation, written communication, March 9, 1995). The bridge is supported by \nvertical, concrete abutments with wingwalls. The channel is skewed approximately 40 \ndegrees to the opening while the opening-skew-to-roadway is 0.0 degrees. \nThe only scour protection measures at the site were type-2 stone fill (less than 36 inches \ndiameter) along the upstream right wingwall and at the upstream end of the right abutment. \nAdditional details describing conditions at the site are included in the Level II Summary \nand Appendices D and E.\nScour depths and rock rip-rap sizes were computed using the general guidelines described \nin Hydraulic Engineering Circular 18 (Richardson and others, 1995). Total scour at a \nhighway crossing is comprised of three components: 1) long-term streambed degradation; \n2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) \nand; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is \nthe sum of the three components. Equations are available to compute depths for contraction \nand local scour and a summary of the results of these computations follows.\nContraction scour for all modelled flows ranged from 1.7 to 1.8 ft. The worst-case \ncontraction scour occurred at the 500-year discharge. Scour at the left abutment ranged \nfrom 7.6 to 12.6 ft with the worst case occurring at the 100-year event. Scour at the right \nabutment ranged from 1.6 to 5.6 ft with the worst case occurring at the 500-year event. \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","doi":"10.3133/ofr96635","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Flynn, R.H., and Song, D.L., 1996, Level II scour analysis for Bridge 6 (RICHTH00030006) on Town Highway 3, crossing an unnamed tributary to the Missisquoi River, Richford, Vermont: U.S. Geological Survey Open-File Report 96-635, iv, 48 p., https://doi.org/10.3133/ofr96635.","productDescription":"iv, 48 p.","numberOfPages":"53","costCenters":[],"links":[{"id":162645,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96635.PNG"},{"id":279281,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0635/report.pdf"}],"country":"United States","state":"Vermont","city":"Richford","otherGeospatial":"Missisquoi River","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.702647,44.921965 ], [ -72.702647,45.015684 ], [ -72.535709,45.015684 ], [ -72.535709,44.921965 ], [ -72.702647,44.921965 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a5c28","contributors":{"authors":[{"text":"Flynn, Robert H. rflynn@usgs.gov","contributorId":2137,"corporation":false,"usgs":true,"family":"Flynn","given":"Robert","email":"rflynn@usgs.gov","middleInitial":"H.","affiliations":[{"id":405,"text":"NH/VT office of New England Water Science Center","active":true,"usgs":true}],"preferred":true,"id":240356,"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":240357,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49846,"text":"ofr96636 - 1996 - Level II scour analysis for Bridge 25 (CLARTH00100025) on Town Highway 10, crossing the Clarendon River, Clarendon, Vermont","interactions":[],"lastModifiedDate":"2013-12-05T14:51:26","indexId":"ofr96636","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":"96-636","title":"Level II scour analysis for Bridge 25 (CLARTH00100025) on Town Highway 10, crossing the Clarendon River, Clarendon, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nCLARTH00100025 on town highway 10 crossing the Clarendon River, Clarendon, \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). Resultsof a Level I scour investigation also are included in Appendix E of this \nreport. A Level I study 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 Taconic Section of the New England physiographic province in westcentral Vermont. The 19.3-mi2\n drainage area is in a predominantly rural basin. In the \nvicinity of the study site, the left and right banks are covered by pasture and (or) fields. The \nright bank of Clarendon River is eroded due to stream-flow attack immediately upstream of \nthe bridge.\nIn the study area, the Clarendon River has a sinuous channel with a slope of approximately \n0.007 ft/ft, an average channel top width of 44 ft and an average channel depth of 3 ft. There \nare large meanders approximately 100 feet upstream and downstream of the bridge. The \npredominant channel bed materials are gravel and cobbles with a median grain size (D50) of \n42.4 mm (0.139 ft). The geomorphic assessment at the time of the Level I and Level II site \nvisit on April 27, 1995, indicated that the reach was laterally unstable.\nThe town highway 10 crossing of the Clarendon River was a 27-ft-long, two-lane bridge \nconsisting of one 24-foot steel stringer with a timber deck (Vermont Agency of \nTransportation, written communication, March 13, 1995). The deck was removed at the \ntime of the survey but the analysis was done as if the old deck was in place. The bridge is \nsupported on the left by a vertical stone abutment and on the right by a vertical, concrete \nabutment with an upstream wingwall. The channel is skewed approximately 10 degrees to \nthe opening while the opening-skew-to-roadway is 0 degrees. \nA scour hole 3 ft deeper than the mean thalweg depth was observed along the right bank \nextending from 24 to 60 feet upstream of the bridge. No scour prevention measures were \nobserved at this site at the time of the site visit. Additional details describing conditions at \nthe site are included in the Level II Summary and Appendices D and E.\nScour depths and rock rip-rap sizes were computed using the general guidelines described \nin Hydraulic Engineering Circular 18 (Richardson and others, 1995). Total scour at a \nhighway crossing is comprised of three components: 1) long-term streambed degradation; \n2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) \nand; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is \nthe sum of the three components. Equations are available to compute depths for contraction \nand local scour and a summary of the results of these computations follows.\nContraction scour for all modelled flows ranged from 0.0 to 0.8 ft. The worst-case \ncontraction scour occurred at the 500-year discharge. Abutment scour ranged from 5.7 to \n10.6 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. \n It is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.","language":"English","publisher":"U.S. Geological Survey","doi":"10.3133/ofr96636","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Ayotte, J., 1996, Level II scour analysis for Bridge 25 (CLARTH00100025) on Town Highway 10, crossing the Clarendon River, Clarendon, Vermont: U.S. Geological Survey Open-File Report 96-636, iv, 50 p., https://doi.org/10.3133/ofr96636.","productDescription":"iv, 50 p.","numberOfPages":"55","costCenters":[],"links":[{"id":162646,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96636.PNG"},{"id":279280,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0636/report.pdf"}],"country":"United States","state":"Vermont","city":"Clarendon","otherGeospatial":"Clarendon River","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -73.050832,43.484502 ], [ -73.050832,43.574704 ], [ -72.92847,43.574704 ], [ -72.92847,43.484502 ], [ -73.050832,43.484502 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b1ae4b07f02db6a8086","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":240358,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":49847,"text":"ofr96637 - 1996 - Level II scour analysis for Bridge 24 (HARDTH00490024) on Town Highway 49, crossing Nichols Brook at Mackville Pond Outlet, Hardwick, Vermont","interactions":[],"lastModifiedDate":"2013-12-05T14:44:37","indexId":"ofr96637","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":"96-637","title":"Level II scour analysis for Bridge 24 (HARDTH00490024) on Town Highway 49, crossing Nichols Brook at Mackville Pond Outlet, Hardwick, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nHARDTH00490024 on Town Highway 49 crossing Nichols Brook at Mackville Pond \nOutlet, Hardwick, Vermont (figures 1–8). A Level II study is a basic engineering analysis of \nthe site, including a quantitative analysis of stream stability and scour (U.S. Department of \nTransportation, 1993). Results of a Level I scour investigation also are included in \nAppendix E of this report. A Level I investigation provides a qualitative geomorphic \ncharacterization of the study site. Information on the bridge, gleaned from Vermont Agency \nof Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II \nanalyses and is found in Appendix D.\nThe site is in the New England Upland section of the New England physiographic province \nin north-central Vermont. The 10.7-mi2\n drainage area is in a predominantly rural and \nforested basin. In the vicinity of the study site, the surface cover is best described as \nsuburban with residences, lawns, trees and roadways.\nThere is a dam 54 feet downstream of the bridge which controls Mackville Pond upstream \nof the bridge. The vertical drop over the dam is 15 feet. Immediately upstream of the bridge \nthe width of the waterway is 146 feet. The predominant channel bed material is sand with a \nmedian grain size (D50) of 0.576 mm (0.00189 ft). The geomorphic assessment at the time \nof the Level I and Level II site visit on July 25, 1995, indicated that the reach was stable.\nThe Town Highway 49 crossing of Nichols Brook at Mackville Pond Outlet is a 42-ft-long, \ntwo-lane bridge consisting of one 38-foot steel-beam span (Vermont Agency of \nTransportation, written communication, April 3, 1995). The bridge is supported by vertical, \nconcrete abutments with wingwalls on the downstream end of the left abutment and \nupstream and downstream ends of the right abutment. The channel is not skewed to the \nopening, but the opening-skew-to-roadway is 5 degrees.\nScour protection measures at the site include type-3 stone fill (less than 48 inches diameter) \non the upstream side of the left roadway embankment and at the upstream end of the left \nabutment. Type-2 stone fill (less than 36 inches diameter) was on the upstream right \nroadway embankment. Additional details describing conditions at the site are included in \nthe Level II Summary and Appendices \nD and E.\nScour depths and rock rip-rap sizes were computed using the general guidelines described \nin Hydraulic Engineering Circular 18 (Richardson and others, 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 4.7 to 21.0 ft. The worst-case \ncontraction scour occurred at the 500-year discharge. Abutment scour at the left abutment \nranged from 13.3 to 15.8 ft. with the worst-case occurring at the 500-year discharge. \nAbutment scour at the right abutment ranged from 8.1 to 9.8 ft. with the worst-case \noccurring at the incipient roadway-overtopping discharge. Additional information on scour \ndepths and depths to armoring are included in the section titled “Scour Results”. Scouredstreambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. \nA cross-section of the scour computed at the bridge is presented in figure 8. Scour depths \nwere calculated assuming an infinite depth of erosive material and a homogeneous particlesize distribution. \nIt is generally accepted that the Froehlich 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","doi":"10.3133/ofr96637","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Olson, S.A., 1996, Level II scour analysis for Bridge 24 (HARDTH00490024) on Town Highway 49, crossing Nichols Brook at Mackville Pond Outlet, Hardwick, Vermont: U.S. Geological Survey Open-File Report 96-637, iv, 51 p., https://doi.org/10.3133/ofr96637.","productDescription":"iv, 51 p.","numberOfPages":"56","costCenters":[],"links":[{"id":162647,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96637.PNG"},{"id":279279,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0637/report.pdf"}],"country":"United States","state":"Vermont","city":"Hardwick","otherGeospatial":"Mackville Pond Outlet","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.434315,44.462456 ], [ -72.434315,44.584125 ], [ -72.262965,44.584125 ], [ -72.262965,44.462456 ], [ -72.434315,44.462456 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b1ae4b07f02db6a80c3","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":240359,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":49848,"text":"ofr96638 - 1996 - Level II scour analysis for Bridge 23 (HARDTH00530023) on Town Highway 53, crossing Haynesville Brook, Hardwick, Vermont","interactions":[],"lastModifiedDate":"2013-12-05T14:34:44","indexId":"ofr96638","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":"96-638","title":"Level II scour analysis for Bridge 23 (HARDTH00530023) on Town Highway 53, crossing Haynesville Brook, Hardwick, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nHARDTH00530023 on Town Highway 53 crossing Haynesville Brook, Hardwick, \nVermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including \na quantitative analysis of stream stability and scour (U.S. Department of Transportation, \n1993). Results of a Level I scour investigation also are included in Appendix E of this \nreport. A Level I investigation provides a qualitative geomorphic characterization of the \nstudy site. Information on the bridge, gleaned from Vermont Agency of Transportation \n(VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is \nfound in Appendix D.\nThe site is in the New England Upland section of the New England physiographic province \nin north-central Vermont. The 14.2-mi2\n drainage area is in a predominantly rural and \nforested basin. In the vicinity of the study site, the predominate surface cover consists of \nfield grasses except for the upstream left bank with is brush covered.\nIn the study area, Haynesville Brook has a sinuous channel with a slope of approximately \n0.004 ft/ft, an average channel top width of 39 ft and an average channel depth of 2 ft. \nStream-bed material at the site ranged from silt to gravel with a median grain size (D50) of \n49.9 mm (0.164ft). The geomorphic assessment at the time of the Level I and Level II site \nvisit on July 27, 1995, indicated that the reach was laterally unstable. Channel scour in both \nthe upstream and downstream reaches as well as irregular point bars and cut banks and \nupstream anabranching led to this assessment. \nThe Town Highway 53 crossing of Haynesville Brook is a 33-ft-long, one-lane bridge \nconsisting of one 26-foot steel-beam span (Vermont Agency of Transportation, written \ncommunication, March 24, 1994). The bridge is supported by vertical, concrete abutments \nwith no wingwalls. The concrete may be facing over the original stone abutments. Sheet \npiling has been driven around the base of each abutment and is filled with concrete. The \nchannel is skewed approximately 10 degrees to the opening; the opening-skew-to-roadway \nis also 10 degrees. Additional details describing conditions at the site are included in the \nLevel II Summary and Appendices D and E.\nScour depths and rock rip-rap sizes were computed using the general guidelines described \nin Hydraulic Engineering Circular 18 (Richardson and others, 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 2.0 ft. The worst-case \ncontraction scour occurred at the 100-year discharge. Abutment scour ranged from 7.0 to \n12.9 ft. The worst-case abutment scour occurred at the 500-year discharge. Additional \ninformation on scour depths and depths to armoring are included in the section titled “Scour \nResults”. Scoured-streambed elevations, based on the calculated scour depths, are presented \nin tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure \n8. Scour depths were calculated assuming an infinite depth of erosive material and a \nhomogeneous particle-size distribution. \nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.","language":"English","publisher":"U.S. Geological Survey","doi":"10.3133/ofr96638","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Olson, S.A., 1996, Level II scour analysis for Bridge 23 (HARDTH00530023) on Town Highway 53, crossing Haynesville Brook, Hardwick, Vermont: U.S. Geological Survey Open-File Report 96-638, iv, 50 p., https://doi.org/10.3133/ofr96638.","productDescription":"iv, 50 p.","numberOfPages":"55","costCenters":[],"links":[{"id":162727,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96638.PNG"},{"id":279278,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0638/report.pdf"}],"country":"United States","state":"Vermont","city":"Hardwick","otherGeospatial":"Haynesville Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.434315,44.462456 ], [ -72.434315,44.584125 ], [ -72.262965,44.584125 ], [ -72.262965,44.462456 ], [ -72.434315,44.462456 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b1ae4b07f02db6a80f9","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":240360,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":49849,"text":"ofr96639 - 1996 - Level II scour analysis for Bridge 49 (WODSTH00990049) on Town Highway 99, crossing Gulf Brook, Woodstock, Vermont","interactions":[],"lastModifiedDate":"2013-12-05T14:25:44","indexId":"ofr96639","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":"96-639","title":"Level II scour analysis for Bridge 49 (WODSTH00990049) on Town Highway 99, crossing Gulf Brook, Woodstock, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nWODSTH00990049 on Town Highway 99 crossing the Gulf Brook, Woodstock, Vermont \n(figures 1–8). A Level II study is a basic engineering analysis of the site, including a \nquantitative analysis of stream stability and scour (U.S. Department of Transportation, \n1993). Results of a Level I scour investigation also are included in Appendix E of this \nreport. A Level I investigation provides a qualitative geomorphic characterization of the \nstudy site. Information on the bridge, gleaned from Vermont Agency of Transportation \n(VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is \nfound in Appendix D.\nThe site is in the New England Upland section of the New England physiographic province \nin east-central Vermont. The 16.8-mi2\n drainage area is in a predominantly rural and forested \nbasin. In the vicinity of the study site, the primary surface cover is pasture except for \nupstream right of the bridge which is cover by trees and brush. The immediate banks \nthroughout the reach have scattered woody vegetation.\nIn the study area, the Gulf Brook has an incised, sinuous channel with a slope of \napproximately 0.01 ft/ft, an average channel top width of 91 ft and an average channel \ndepth of 6 ft. The channel bed materials range from sand to cobble with a median grain size \n(D50) of 85.3 mm (0.280 ft). The geomorphic assessment at the time of the Level I site visits \non September 15, 1994 and December 14, 1994, indicated that the reach was stable.\nThe Town Highway 99 crossing of the Gulf Brook is a 56-ft-long, one-lane bridge \nconsisting of one 55-foot steel-beam span (Vermont Agency of Transportation, written \ncommunication, April 4, 1995). The bridge is supported by vertical, concrete abutments \nwith a spill-through slope constructed of large quarried stone. The channel is skewed \napproximately 20 degrees to the opening while the opening-skew-to-roadway is 0 degrees. \nErosion at the right abutment has undermined the toe of the spill-through slope by nearly a \nfoot. Material has been removed from under the stone spill-through slope so that 0.5 feet of \nhorizontal penetration was possible at the time of the visits. 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, 1995). Total scour at a \nhighway crossing is comprised of three components: 1) long-term streambed degradation; \n2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) \nand; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is \nthe sum of the three components. Equations are available to compute depths for contraction \nand local scour and a summary of the results of these computations follows.\nContraction scour for all modelled flows ranged from 0.0 to 0.9 ft. The worst-case \ncontraction scour occurred at the 500-year discharge. Abutment scour at the left abutment \nranged from 3.1 to 10.3 ft. with the worst-case occurring at the 500-year discharge. \nAbutment scour at the right abutment ranged from 6.4 to 10.4 ft. with the worst-case \noccurring at the 100-year discharge.Additional information on scour depths and depths to \narmoring are included in the section titled “Scour Results”. Scoured-streambed elevations, \nbased on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the \nscour computed at the bridge is presented in figure 8. Scour depths were calculated \nassuming an infinite depth of erosive material and a homogeneous particle-size distribution. \nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.","language":"English","publisher":"U.S. Geological Survey","doi":"10.3133/ofr96639","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Olson, S.A., and Hammond, R.E., 1996, Level II scour analysis for Bridge 49 (WODSTH00990049) on Town Highway 99, crossing Gulf Brook, Woodstock, Vermont: U.S. Geological Survey Open-File Report 96-639, iv, 50 p., https://doi.org/10.3133/ofr96639.","productDescription":"iv, 50 p.","numberOfPages":"55","costCenters":[],"links":[{"id":162728,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96639.PNG"},{"id":279277,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0639/report.pdf"}],"country":"United States","state":"Vermont","city":"Woodstock","otherGeospatial":"Gulf Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.637941,43.533341 ], [ -72.637941,43.661214 ], [ -72.46644,43.661214 ], [ -72.46644,43.533341 ], [ -72.637941,43.533341 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a610d","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":240361,"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":240362,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49850,"text":"ofr96640 - 1996 - Level II scour analysis for Bridge 1 (CANATH00010001) on Town Highway 1, crossing Halls Stream, Canaan, Vermont","interactions":[],"lastModifiedDate":"2013-12-05T14:19:55","indexId":"ofr96640","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":"96-640","title":"Level II scour analysis for Bridge 1 (CANATH00010001) on Town Highway 1, crossing Halls Stream, Canaan, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nCANATH00010001 on town highway 1 crossing Halls Stream, Canaan, 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 I \nstudy is included in Appendix E of this report. A Level I study provides a qualitative \ngeomorphic characterization of the study site. Information on the bridge, gleaned from \nVermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level \nI and Level II analyses and can be found in Appendix D.\nThe site is in the White Mountain section of the New England physiographic province of \nnortheastern Vermont in the town of Canaan. The 89.5-mi2\n drainage area is in a \npredominantly rural and forested basin. In the vicinity of the study site, the banks have tree, \nshrub and brush, and grass vegetation coverage.\nIn the study area, Halls Stream has a sinuous channel with a slope of approx-imately 0.0012 \nft/ft, an average channel top width of 109 ft and an average channel depth of 4 ft. The \npredominant channel bed materials are sand and gravel (D50 is 5.03 mm or 0.0165 ft). The \ngeomorphic assessment at the time of the Level I and Level II site visit on October 27, \n1994, indicated that the reach was laterally unstable. The lateral instability was evident due \nto a wide point-bar and cut-banks with undermining of bank material, slumping, fallen bank \nvegetation evident in the upstream channel. \nThe town highway 1 crossing of Halls Stream is a 99-ft-long, two-lane bridge consisting of \none 33-foot and two 31-foot concrete T-beam spans (Vermont Agency of Transportation, \nwritten communication, August 5, 1994). The bridge is supported by vertical, concrete \nabutments with spill-through embankments in front of each abutment wall. The channel is \nskewed approximately 10 degrees to the opening while the opening-skew-to-roadway is \nzero degrees. \nThere are two piers in the channel at this site. Field notes and the channel survey at the \nbridge indicate that the streambed elevation is higher on the downstream right sides of each \npier and lower on the downstream left sides. This asymmetrical streambed condition\nsuggests a flow attack angle may influence scour on each pier. Furthermore, field \nobservations suggest that the flow attack angle is higher for the right pier (pier 2) than the \nleft pier (pier 1).\nThe scour protection measures at the site were type-2 stone fill (less than 36 inches \ndiameter) on both upstream banks and both downstream road embankments. Type-3 stone \nfill (less than 48 inches diameter) was found on the spill-through slopes of each abutment \nand both downstream banks. The stone fill protection on the spill-through embankment of \nthe right abutment was noted as slumped with some of the fill material evident in the \nchannel immediately downstream of the bridge. Additional details describing conditions at \nthe site are included in the Level II Summary and Appendices D and E.\nScour depths and 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 8.0 to 8.8 ft. The worst-case \ncontraction scour occurred at the 500-year discharge. Abutment scour ranged from 8.9 to \n17.3 ft. The worst-case abutment scour occurred at the 500-year discharge. For the two \npiers, scour ranged from 11.1 to 15.8. The worst-case pier scour occurred for pier2 at the \nincipient overtopping discharge. Additional information on scour depths and depths to \narmoring are included in the section titled “Scour Results”. Scoured-streambed elevations, \nbased on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the \nscour computed at the bridge is presented in figure 8. Scour depths were calculated \nassuming an infinite depth of erosive material and a homogeneous particle-size distribution. \nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.","language":"English","publisher":"U.S. Geological Survey","doi":"10.3133/ofr96640","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Boehmler, E.M., 1996, Level II scour analysis for Bridge 1 (CANATH00010001) on Town Highway 1, crossing Halls Stream, Canaan, Vermont: U.S. Geological Survey Open-File Report 96-640, iv, 51 p., https://doi.org/10.3133/ofr96640.","productDescription":"iv, 51 p.","numberOfPages":"56","costCenters":[],"links":[{"id":162729,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96640.PNG"},{"id":279276,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0640/report.pdf"}],"country":"United States","state":"Vermont","city":"Canaan","otherGeospatial":"Halls Stream","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -71.705447,44.906853 ], [ -71.705447,45.013639 ], [ -71.465039,45.013639 ], [ -71.465039,44.906853 ], [ -71.705447,44.906853 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b1ae4b07f02db6a8490","contributors":{"authors":[{"text":"Boehmler, Erick M.","contributorId":96303,"corporation":false,"usgs":true,"family":"Boehmler","given":"Erick","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":240363,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":49851,"text":"ofr96641 - 1996 - Level II scour analysis for Bridge 36 (RANDTH00480036) on Town Highway 48, crossing Snows Brook, Randolph, Vermont","interactions":[],"lastModifiedDate":"2013-12-05T14:28:19","indexId":"ofr96641","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":"96-641","title":"Level II scour analysis for Bridge 36 (RANDTH00480036) on Town Highway 48, crossing Snows Brook, Randolph, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nRANDTH00480036 on town highway 48 crossing Snows Brook, Randolph, 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. The 3.72-mi2\n drainage area is in a predominantly rural and forested basin. \nIn the vicinity of the study site, the surface cover is forest.\nIn the study area, Snows Brook has an incised, sinuous channel with a slope of \napproximately 0.03 ft/ft, an average channel top width of 27 ft and an average channel \ndepth of 3 ft. The predominant channel bed material is cobble with a median grain size \n(D50) of 72.7 mm (0.238 ft). The geomorphic assessment at the time of the Level I and \nLevel II site visit on August 9, 1994, indicated that the reach was laterally unstable.\nThe town highway 48 crossing of Snows Brook is a 32-ft-long, two-lane bridge consisting \nof one 28-foot concrete span (Vermont Agency of Transportation, written communication, \nJuly 29, 1994). The bridge is supported by vertical, concrete abutments with wingwalls. The \nchannel is skewed approximately 40 degrees to the opening while the opening-skew-toroadway is 45 degrees. Additional details describing conditions at the site are included in \nthe Level II Summary and Appendices D and E.\nScour depths and rock rip-rap sizes were computed using the general guidelines described \nin Hydraulic Engineering Circular 18 (Richardson and others, 1995). Total scour at a \nhighway crossing is comprised of three components: 1) long-term streambed degradation; \n2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) \nand; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is \nthe sum of the three components. Equations are available to compute depths for contraction \nand local scour and a summary of the results of these computations follows.\nContraction scour for all modelled flows ranged from 0.0 to 0.8 ft. The worst-case \ncontraction scour occurred at the 500-year discharge. Abutment scour ranged from 6.1 to \n11.6 ft. The worst-case abutment scour occurred at the incipient-overtopping discharge, \nwhich was 50 cfs lower than the 500-year discharge. Additional information on scour \ndepths and depths to armoring are included in the section titled “Scour Results”. Scouredstreambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. \nA cross-section of the scour computed at the bridge is presented in figure 8. Scour depths \nwere calculated assuming an infinite depth of erosive material and a homogeneous particlesize distribution. \n It is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.","language":"English","publisher":"U.S. Geological Survey","doi":"10.3133/ofr96641","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Olson, S.A., 1996, Level II scour analysis for Bridge 36 (RANDTH00480036) on Town Highway 48, crossing Snows Brook, Randolph, Vermont: U.S. Geological Survey Open-File Report 96-641, iv, 49 p., https://doi.org/10.3133/ofr96641.","productDescription":"iv, 49 p.","numberOfPages":"54","costCenters":[],"links":[{"id":162730,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96641.PNG"},{"id":279274,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0641/report.pdf"}],"country":"United States","state":"Vermont","city":"Randolph","otherGeospatial":"Snows Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.703521,43.873348 ], [ -72.703521,44.000618 ], [ -72.509922,44.000618 ], [ -72.509922,43.873348 ], [ -72.703521,43.873348 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a63fa","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":240364,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":49853,"text":"ofr96643 - 1996 - Level II scour analysis for Bridge 41 (BAKEVT01080041) on State Route 108 crossing The Branch, Bakersfield, Vermont","interactions":[],"lastModifiedDate":"2013-11-20T14:43:24","indexId":"ofr96643","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":"96-643","title":"Level II scour analysis for Bridge 41 (BAKEVT01080041) on State Route 108 crossing The Branch, Bakersfield, Vermont","language":"ENGLISH","doi":"10.3133/ofr96643","usgsCitation":"Boehmler, E., and Degnan, J., 1996, Level II scour analysis for Bridge 41 (BAKEVT01080041) on State Route 108 crossing The Branch, Bakersfield, Vermont: U.S. Geological Survey Open-File Report 96-643, 48 p., https://doi.org/10.3133/ofr96643.","productDescription":"48 p.","costCenters":[],"links":[{"id":162732,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/usgs_thumb.jpg"},{"id":279272,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0643/report.pdf"}],"noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a61b5","contributors":{"authors":[{"text":"Boehmler, E.M.","contributorId":88405,"corporation":false,"usgs":true,"family":"Boehmler","given":"E.M.","affiliations":[],"preferred":false,"id":240368,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Degnan, J.R.","contributorId":18423,"corporation":false,"usgs":true,"family":"Degnan","given":"J.R.","email":"","affiliations":[],"preferred":false,"id":240367,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49855,"text":"ofr96645 - 1996 - Level II scour analysis for Bridge 7 (BERKTH00030007) on Town Highway 3, crossing the Pike River, Berkshire, Vermont","interactions":[],"lastModifiedDate":"2013-11-20T14:42:37","indexId":"ofr96645","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":"96-645","title":"Level II scour analysis for Bridge 7 (BERKTH00030007) on Town Highway 3, crossing the Pike River, Berkshire, Vermont","language":"ENGLISH","doi":"10.3133/ofr96645","usgsCitation":"Boehmler, E., and Ivanoff, M., 1996, Level II scour analysis for Bridge 7 (BERKTH00030007) on Town Highway 3, crossing the Pike River, Berkshire, Vermont: U.S. Geological Survey Open-File Report 96-645, 48 p., https://doi.org/10.3133/ofr96645.","productDescription":"48 p.","costCenters":[],"links":[{"id":162283,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/usgs_thumb.jpg"},{"id":279270,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0645/report.pdf"}],"noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b16e4b07f02db6a57b2","contributors":{"authors":[{"text":"Boehmler, E.M.","contributorId":88405,"corporation":false,"usgs":true,"family":"Boehmler","given":"E.M.","affiliations":[],"preferred":false,"id":240371,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Ivanoff, M.A.","contributorId":45758,"corporation":false,"usgs":true,"family":"Ivanoff","given":"M.A.","email":"","affiliations":[],"preferred":false,"id":240370,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49856,"text":"ofr96741 - 1996 - Level II scour analysis for Bridge 37 (CONCTH00010037) on Town Highway 1, crossing the Moose River, Concord, Vermont","interactions":[],"lastModifiedDate":"2013-11-22T09:42:16","indexId":"ofr96741","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":"96-741","title":"Level II scour analysis for Bridge 37 (CONCTH00010037) on Town Highway 1, crossing the Moose River, Concord, Vermont","language":"ENGLISH","doi":"10.3133/ofr96741","usgsCitation":"Olson, S., 1996, Level II scour analysis for Bridge 37 (CONCTH00010037) on Town Highway 1, crossing the Moose River, Concord, Vermont: U.S. Geological Survey Open-File Report 96-741, 50 p., https://doi.org/10.3133/ofr96741.","productDescription":"50 p.","costCenters":[],"links":[{"id":162284,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/usgs_thumb.jpg"},{"id":279572,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0741/report.pdf"}],"noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a6371","contributors":{"authors":[{"text":"Olson, S.A.","contributorId":58681,"corporation":false,"usgs":true,"family":"Olson","given":"S.A.","email":"","affiliations":[],"preferred":false,"id":240372,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":49858,"text":"ofr96743 - 1996 - Level II scour analysis for Bridge 5 (CHELTH00030005) on Town Highway 3, crossing Jenkins Brook, Chelsea, Vermont","interactions":[],"lastModifiedDate":"2013-12-13T16:03:44","indexId":"ofr96743","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":"96-743","title":"Level II scour analysis for Bridge 5 (CHELTH00030005) on Town Highway 3, crossing Jenkins Brook, Chelsea, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nCHELTH00030005 on town highway 3 crossing Jenkins Brook, Chelsea, 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 \nof a Level I scour investigation also are included in Appendix E of this report. A Level I \nstudy provides a qualitative geomorphic characterization of the study site. Information on \nthe bridge, gleaned from Vermont Agency of Transportation (VTAOT) files, was compiled \nprior to conducting Level I and Level II analyses and is found in Appendix D.\nThe site is in the New England Upland section of the New England physiographic province \nof central Vermont in the town of Chelsea. The 6.97-mi2\n drainage area is in a \npredominantly rural and forested basin. In the vicinity of the study site, the surface cover is \nforest.\nIn the study area, Jenkins Brook has an incised, sinuous channel with a slope of \napproximately 0.04 ft/ft, an average channel top width of 48 ft and an average channel \ndepth of 3 ft. The predominant channel bed material is cobble with a median grain size \n(D50) of 154 mm (0.506 ft). The geomorphic assessment at the time of the Level I and Level \nII site visit on November 17, 1994, indicated that the reach was stable.\nThe town highway 3 crossing of Jenkins Brook is a 23-ft-long bridge consisting of one 20-\nfoot concrete span (Vermont Agency of Transportation, written communication, August 25, \n1994). The bridge is supported by vertical, concrete abutments with wingwalls. The \nupstream wingwalls are protected by type-3 stone fill (less than 48 inches diameter) and the \ndownstream wingwalls have type-2 stone fill (less than 36 inches diameter). The footings of \nboth abutments are exposed. The channel is skewed approximately 25 degrees to the \nopening while the opening-skew-to-roadway is 15 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, 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 was 0.0 ft. Abutment scour ranged from 7.6 to \n12.4 ft. The worst-case abutment scour occurred at the 500-year discharge. Additional \ninformation on scour depths and depths to armoring are included in the section titled “Scour \nResults”. Scoured-streambed elevations, based on the calculated scour depths, are presented \nin tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure \n8. Scour depths were calculated assuming an infinite depth of erosive material and a \nhomogeneous particle-size distribution.\n It is generally accepted that the Froehlich equation (abutment scour) gives \n“excessively conservative estimates of scour depths” (Richardson and others, 1995, \np. 47). Usually, computed scour depths are evaluated in combination with other \ninformation including (but not limited to) historical performance during flood \nevents, the geomorphic stability assessment, existing scour protection measures, \nand the results of the hydraulic analyses. Therefore, scour depths adopted by \nVTAOT may differ from the computed values documented herein.","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr96743","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Ivanoff, M.A., 1996, Level II scour analysis for Bridge 5 (CHELTH00030005) on Town Highway 3, crossing Jenkins Brook, Chelsea, Vermont: U.S. Geological Survey Open-File Report 96-743, iv, 49 p., https://doi.org/10.3133/ofr96743.","productDescription":"iv, 49 p.","numberOfPages":"54","costCenters":[],"links":[{"id":162286,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96743.PNG"},{"id":279574,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0743/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Chelsea","otherGeospatial":"Jenkins Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.5,43.875 ], [ -72.5,44.0 ], [ -72.375,44.0 ], [ -72.375,43.875 ], [ -72.5,43.875 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a5f52","contributors":{"authors":[{"text":"Ivanoff, Michael A.","contributorId":27105,"corporation":false,"usgs":true,"family":"Ivanoff","given":"Michael","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":240374,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":49859,"text":"ofr96744 - 1996 - Level II scour analysis for Bridge 38 (CONCTH00060038) on Town Highway 6, crossing the Moose River, Concord, Vermont","interactions":[],"lastModifiedDate":"2013-12-13T16:17:19","indexId":"ofr96744","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":"96-744","title":"Level II scour analysis for Bridge 38 (CONCTH00060038) on Town Highway 6, crossing the Moose River, Concord, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nCONCTH00060038 on Town Highway 6 crossing the Moose River, Concord, Vermont \n(figures 1–8). A Level II study is a basic engineering analysis of the site, including a \nquantitative analysis of stream stability and scour (U.S. Department of Transportation, \n1993). Results of a Level I scour investigation also are included in Appendix E of this \nreport. A Level I investigation provides a qualitative geomorphic characterization of the \nstudy site. Information on the bridge, gleaned from Vermont Agency of Transportation \n(VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is \nfound in Appendix D.\nApproximately 85 percent of the drainage above the site is in the White Mountain section \nand 15 percent is in the New England Upland section of the New England physiographic \nprovince in northeastern Vermont. The 98.4-mi2\n drainage area is in a predominantly rural \nand forested basin. In the vicinity of the study site, the surface cover of the banks is \nprimarily forest and brush.\nIn the study area, the Moose River has an incised, sinuous channel with a slope of \napproximately 0.009 ft/ft, an average channel top width of 110 ft and an average channel \ndepth of 6 ft. The channel bed material ranged from gravel to boulder and had a median \ngrain size (D50) of 74.4 mm (0.244 ft). The geomorphic assessment at the time of the Level \nI and Level II site visit on August 17, 1995, indicated that the reach was stable.\nThe Town Highway 6 crossing of the Moose River is a 59-ft-long, two-lane bridge \nconsisting of one 55-foot steel-beam span (Vermont Agency of Transportation, written \ncommunication, March 24, 1995). The bridge is supported by a vertical, laid-up stone \nabutment with wingwalls on the left and a vertical, concrete abutment with wingwalls on \nthe right. The channel is skewed approximately 10 degrees to the opening while the \nopening-skew-to-roadway is 0 degrees.\nThe footing of the left abutment is exposed as much as 2.8 feet. The footing of the right \nabutment is undermined vertically by as much as 0.3 feet. Type-2 stone-fill (less than 36 \ninches diameter) protection can be found along the left abutment. Type-3 stone-fill (less \nthan 48 inches diameter) protection can be found along the right abutment. Additional \ndetails describing conditions at the site are included in the Level II Summary and \nAppendices 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 0.1 to 3.1 ft. The worst-case \ncontraction scour occurred at the incipient-overtopping discharge. Abutment scour at the \nleft abutment ranged from 10.4 to 12.5 ft with the worst-case occurring at the 500-year \ndischarge. Abutment scour at the right abutment ranged from 25.3 to \n27.3 ft with the worst-case occurring at the incipient-overtopping discharge. The worst-case \ntotal scour also occurred at the incipient-overtopping discharge. The incipient-overtopping \ndischarge was in between the 100- and 500-year discharges. Additional information on \nscour depths and depths to armoring are included in the section titled “Scour Results”. \nScoured-streambed elevations, based on the calculated scour depths, are presented in tables \n1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour \ndepths were calculated assuming an infinite depth of erosive material and a homogeneous \nparticle-size distribution. \nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr96744","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Olson, S.A., 1996, Level II scour analysis for Bridge 38 (CONCTH00060038) on Town Highway 6, crossing the Moose River, Concord, Vermont: U.S. Geological Survey Open-File Report 96-744, iv, 50 p., https://doi.org/10.3133/ofr96744.","productDescription":"iv, 50 p.","numberOfPages":"55","costCenters":[],"links":[{"id":170312,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96744.PNG"},{"id":279575,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0744/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Concord","otherGeospatial":"Moose River","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ 72.0,44.375 ], [ 72.0,44.5 ], [ 71.875,44.5 ], [ 71.875,44.375 ], [ 72.0,44.375 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a6231","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":240375,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":49860,"text":"ofr96745 - 1996 - Level II scour analysis for Bridge 43 (HARDTH00CU0043) on Church Street, crossing the Lamoille River, Hardwick, Vermont","interactions":[],"lastModifiedDate":"2013-12-17T10:45:17","indexId":"ofr96745","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":"96-745","title":"Level II scour analysis for Bridge 43 (HARDTH00CU0043) on Church Street, crossing the Lamoille River, Hardwick, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nHARDTH00CU0043 on Church Street crossing the Lamoille River, Hardwick, Vermont \n(figures 1–8). A Level II study is a basic engineering analysis of the site, including a \nquantitative analysis of stream stability and scour (U.S. Department of Transportation, \n1993). Results of a Level I scour investigation also are included in Appendix E of this \nreport. A Level I investigation provides a qualitative geomorphic characterization of the \nstudy site. Information on the bridge, gleaned from Vermont Agency of Transportation \n(VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is \nfound in Appendix D.\nThe site is in the New England Upland section of the New England physiographic province \nin north-central Vermont. The 87.6-mi2\n drainage area is in a predominantly rural and \nforested basin. In the vicinity of the study site, the surface cover is best characterized as \nsuburban except for the downstream right surface cover which is pasture.\nIn the study area, the Lamoille River has an incised, straight channel with a slope of \napproximately 0.004 ft/ft, an average channel top width of 90 ft and an average channel \ndepth of 8 ft. The predominant channel bed materials are cobble and gravel with a median \ngrain size (DM50) of 99.5 mm (0.327 ft). The geomorphic assessment at the time of the Level \nI and Level II site visit on July 26, 1995, indicated that the reach was stable.\nThe Church Street crossing of the Lamoille River is a 100-ft-long, two-lane bridge \nconsisting of one 97-foot steel-beam span (Vermont Agency of Transportation, written \ncommunication, March 17, 1995). The bridge is supported by a vertical, stone abutment \nwith wingwalls on the left and a vertical concrete abutment with a stone spill-through slope \non the right. The channel is skewed approximately 5 degrees to the opening while the \nopening-skew-to-roadway is 0 degrees. Additional details describing conditions at the site \nare included in the Level II Summary and Appendices D and E.\nScour depths and rock rip-rap sizes were computed using the general guidelines described \nin Hydraulic Engineering Circular 18 (Richardson and others, 1995). Total scour at a \nhighway crossing is comprised of three components: 1) long-term streambed degradation; \n2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) \nand; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is \nthe sum of the three components. Equations are available to compute depths for contraction \nand local scour and a summary of the results of these computations follows.\nContraction scour for all modelled flows ranged from 0.0 to 0.8 ft. The worst-case \ncontraction scour occurred at the incipient-overtopping discharge. Abutment scour ranged \nfrom 6.2 to 10.9 ft at the left abutment with worst-case occurring at the incipientovertopping discharge. Abutment scour ranged from 8.5 to 12.3 ft at the right abutment with \nworst-case 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 crosssection of the scour computed at the bridge is presented in figure 8. Scour depths were \ncalculated assuming an infinite depth of erosive material and a homogeneous particle-size \ndistribution. \nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr96745","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Olson, S.A., 1996, Level II scour analysis for Bridge 43 (HARDTH00CU0043) on Church Street, crossing the Lamoille River, Hardwick, Vermont: U.S. Geological Survey Open-File Report 96-745, iv, 52 p., https://doi.org/10.3133/ofr96745.","productDescription":"iv, 52 p.","numberOfPages":"57","costCenters":[],"links":[{"id":170313,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96745.PNG"},{"id":279576,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0745/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Hardwick","otherGeospatial":"Lamoille River","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.5,44.375 ], [ -72.5,44.625 ], [ -72.25,44.625 ], [ -72.25,44.375 ], [ -72.5,44.375 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a61b9","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":240376,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":49861,"text":"ofr96746 - 1996 - Level II scour analysis for Bridge 37 (BARTUS00050166) on U.S. Route 5, crossing Barton River, Barton, Vermont","interactions":[],"lastModifiedDate":"2013-12-17T10:53:37","indexId":"ofr96746","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":"96-746","title":"Level II scour analysis for Bridge 37 (BARTUS00050166) on U.S. Route 5, crossing Barton River, Barton, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nBARTUS00050166 on U. S. Route 5 crossing the Barton River, Barton, Vermont (figures \n1–8). A Level II study is a basic engineering analysis of the site, including a quantitative \nanalysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of \na Level I scour investigation also are included in Appendix E of this report. A Level I \ninvestigation provides a qualitative geomorphic characterization of the study site. \nInformation on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) \nfiles, was compiled prior to conducting Level I and Level II analyses and is found in \nAppendix D.\nThe site is in the New England Upland section of the New England physiographic province \nof north-central Vermont in the town of Barton. The 65.2-mi2\n drainage area is in a \npredominantly rural and forested basin. In the vicinity of the study site, the banks have a \ncombination of dense woody vegetation coverage, brush, and field grasses.\nIn the study area, the Barton River has an incised, sinuous-to-meandering channel with a \nslope of approximately 0.0065 ft/ft, an average channel top width of 58 ft and an average \nchannel depth of 4 ft. The predominant channel bed material is gravel (D50 is 75.6 mm or \n0.25 ft). The geomorphic assessment at the time of the Level I and Level II site visit on \nOctober 19, 1994, indicated that the reach was stable.\nThe U. S. Route 5 crossing of the Barton River is a 126-ft-long, two-lane bridge consisting \nof one 60-foot steel beam span with two steel-beam approach spans (Vermont Agency of \nTransportation, written communication, August 4, 1994). The bridge is supported by two \nconcrete piers. The left bank has a concrete retaining wall that is attached to the US face of \nthe left pier; consequently this pier functions as an abutment for the analysis because no \nflow occurs to the left of the pier. For the purposes of computing scour, this pier was \nconsidered an abutment. The channel is skewed approximately 40 degrees to the opening \nwhile the opening-skew-to-roadway is 25 degrees.\nA scour hole 0.5 ft deeper than the mean thalweg depth was observed along the right pier \nduring the Level I assessment. Scour protection measures at the site consist of type-1 stone \nfill (less than 12 inches diameter) along the entire base length of both piers. Additional \ndetails describing conditions at the site are included in the Level II Summary and \nAppendices 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 1.1 to 2.4 ft. Abutment-type scour \nwas computed for the left pier; scour ranged from 9.1 to 11.3 ft. Abutment scour at the right \nabutment ranged from 6.1 to 11.3 ft. Pier scour, computed for the right pier, ranged from \n31.3 to 33.3 ft. The severity of the pier scour was directly related to the attack angle of 25 \ndegrees. The worst-case scour in all computations 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/ofr96746","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Ayotte, J., and Hammond, R.E., 1996, Level II scour analysis for Bridge 37 (BARTUS00050166) on U.S. Route 5, crossing Barton River, Barton, Vermont: U.S. Geological Survey Open-File Report 96-746, iv, 50 p., https://doi.org/10.3133/ofr96746.","productDescription":"iv, 50 p.","numberOfPages":"55","costCenters":[],"links":[{"id":170314,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96746.PNG"},{"id":279577,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0746/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Barton","otherGeospatial":"Barton River","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.25,44.75 ], [ -72.25,44.875 ], [ -72.125,44.875 ], [ -72.125,44.75 ], [ -72.25,44.75 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a63c8","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":240377,"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":240378,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49862,"text":"ofr96747 - 1996 - Level II scour analysis for Bridge 145 (HANCVT01000145) on Vermont Highway 100, crossing the Hancock Branch of the White River, Hancock, Vermont","interactions":[],"lastModifiedDate":"2013-12-17T11:02:46","indexId":"ofr96747","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":"96-747","title":"Level II scour analysis for Bridge 145 (HANCVT01000145) on Vermont Highway 100, crossing the Hancock Branch of the White River, Hancock, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nHANCVT01000145 on State Route 100 crossing the Hancock Branch of the White River, \nHancock, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, \nincluding a quantitative analysis of stream stability and scour (U.S. Department of \nTransportation, 1993). Results of a Level I scour investigation also are included in \nAppendix E of this report. A Level I investigation provides a qualitative geomorphic \ncharacterization of the study site. Information on the bridge, gleaned from Vermont Agency \nof Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II \nanalyses and is found in Appendix D.\nThe site is in the Green Mountain section of the New England physiographic province in \ncentral Vermont. The 22.0-mi2\n drainage area is in a predominantly rural and forested basin. \nIn the vicinity of the study site, the surface cover is urban on left bank and forested on the \nright bank upstream of the bridge while the immediate banks have woody vegetation. \nDownstream of the bridge surface cover on both banks is pasture while the immediate \nbanks have woody vegetation.\nIn the study area, the Hancock Branch of the White River has an incised, sinuous channel \nwith a slope of approximately 0.006 ft/ft, an average channel top width of 48 ft and an \naverage channel depth of 3 ft. The predominant channel bed materials are cobble and gravel \nwith a median grain size (D50) of 71.9 mm (0.236 ft). The geomorphic assessment at the \ntime of the Level I and Level II site visit on November 16, 1994, indicated that the reach \nwas stable.\nState Route 100 crossing the Hancock Branch of the White River is a 55-ft-long, two-lane\nbridge consisting of one 53-foot steel-beam span (Vermont Agency of Transportation, \nwritten communication, August 26, 1994). The bridge is supported by vertical, concrete\nabutments with wingwalls. The channel is not skewed to the opening and the opening-skewto-roadway is 0 degrees. \nThe only scour protection measures at the site were type-3 stone fill (less than 48 inches \ndiameter) at the upstream right wingwall, both downstream wingwalls and the downstream \nends of both abutments. Also there was type-2 stone fill (less than 36 inches diameter) at the \nupstream left wingwall. Additional details describing conditions at the site are included in \nthe Level II Summary and Appendices D \nand E.\nScour depths and rock rip-rap sizes were computed using the general guidelines described \nin Hydraulic Engineering Circular 18 (Richardson and others, 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 3.4 to 4.3 ft. The worst-case \ncontraction scour occurred at the 500-year discharge. Abutment scour ranged from 8.2 to \n11.1 ft. The worst-case abutment scour occurred at the 100-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/ofr96747","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Ivanoff, M.A., and Hammond, R.E., 1996, Level II scour analysis for Bridge 145 (HANCVT01000145) on Vermont Highway 100, crossing the Hancock Branch of the White River, Hancock, Vermont: U.S. Geological Survey Open-File Report 96-747, iv, 50 p., https://doi.org/10.3133/ofr96747.","productDescription":"iv, 50 p.","numberOfPages":"55","costCenters":[],"links":[{"id":170315,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96747.PNG"},{"id":279578,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0747/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":"4f4e4b1ae4b07f02db6a82fa","contributors":{"authors":[{"text":"Ivanoff, Michael A.","contributorId":27105,"corporation":false,"usgs":true,"family":"Ivanoff","given":"Michael","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":240379,"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":240380,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49863,"text":"ofr96748 - 1996 - Level II scour analysis for Bridge 59 (NWPCVT01050059) on State Route 105 crossing an unnamed Mud Creek Tributary, Newport, Vermont","interactions":[],"lastModifiedDate":"2013-12-17T11:08:35","indexId":"ofr96748","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":"96-748","title":"Level II scour analysis for Bridge 59 (NWPCVT01050059) on State Route 105 crossing an unnamed Mud Creek Tributary, Newport, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nNWPCVT01050059 on state route 105 crossing an unnamed Mud Creek tributary, \nNewport, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, \nincluding a quantitative analysis of stream stability and scour (U.S. Department of \nTransportation, 1993). Results of a Level I scour investigation also are included in \nAppendix E of this report. A Level I investigation provides a qualitative geomorphic \ncharacterization of the study site. Information on the bridge, gleaned from Vermont Agency \nof Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II \nanalyses and is found in Appendix D.\nThe site is in the New England Upland section of the New England physiographic province \nof north-central Vermont in the town of Newport. The 9.18-mi2\n drainage area is in a \npredominantly rural and forested basin. In the vicinity of the study site, the surface cover is \npasture while the immediate banks are brush covered with some trees. \nIn the study area, this unnamed Mud Creek tributary has an incised, sinuous channel with a \nslope of approximately 0.005 ft/ft, an average channel top width of 42 ft and an average \nchannel depth of 5 ft. The predominant channel bed materials are gravel and cobbles with a \nmedian grain size (D50) of 54.1 mm (0.178 ft). The geomorphic assessment at the time of \nthe Level I and Level II site visit on October 21, 1994, indicated that the reach was stable.\nThe state route 105 crossing of an unnamed Mud Creek tributary is a 33-ft-long, two-lane \nbridge consisting of one 29-foot concrete-slab span (Vermont Agency of Transportation, \nwritten communication, August 5, 1994). The bridge is supported by vertical, concrete \nabutments with wingwalls. The channel is skewed approximately 15 degrees to the opening \nand the opening-skew-to-roadway is 15 degrees. \nScour protection measures at the site were type-2 stone fill (less than 36 inches diameter) on \neach bank upstream and both upstream wingwalls. The downstream wingwalls are \nprotected by remnant abutment walls from a previous structure. 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 0.2 to 0.5 ft. The worst-case \ncontraction scour occurred at the 500-year discharge. Abutment scour ranged from 5.2 to \n16.6 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/ofr96748","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Boehmler, E.M., and Ivanoff, M.A., 1996, Level II scour analysis for Bridge 59 (NWPCVT01050059) on State Route 105 crossing an unnamed Mud Creek Tributary, Newport, Vermont: U.S. Geological Survey Open-File Report 96-748, iv, 48 p., https://doi.org/10.3133/ofr96748.","productDescription":"iv, 48 p.","numberOfPages":"53","costCenters":[],"links":[{"id":170316,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96748.PNG"},{"id":279579,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0748/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Newport","otherGeospatial":"Mud Creek Tributary","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":"4f4e4b17e4b07f02db6a5a81","contributors":{"authors":[{"text":"Boehmler, Erick M.","contributorId":96303,"corporation":false,"usgs":true,"family":"Boehmler","given":"Erick","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":240382,"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":240381,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49864,"text":"ofr96749 - 1996 - Level II scour analysis for Bridge 13 (IRAVT013300133) on State Route 133, crossing an Ira Brook Tributary, Ira, Vermont","interactions":[],"lastModifiedDate":"2013-12-17T12:28:23","indexId":"ofr96749","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":"96-749","title":"Level II scour analysis for Bridge 13 (IRAVT013300133) on State Route 133, crossing an Ira Brook Tributary, Ira, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nIRA-VT01330013 on State Route 133 crossing an Ira Brook Tributary, Ira, 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 Taconic section of the New England physiographic province in westcentral Vermont. The 2.88-mi2\n drainage area is in a predominantly rural and forested basin. \nIn the vicinity of the study site, the surface cover is pasture while the immediate banks have \ndense tree cover.\nIn the study area, this Ira Brook Tributary has an incised, sinuous channel with a slope of \napproximately 0.02 ft/ft, an average channel top width of 40 ft and an average channel \ndepth of 7 ft. The predominant channel bed material is cobble with a median grain size \n(D50) of 71.9 mm (0.236 ft). The geomorphic assessment at the time of the Level I and \nLevel II site visit on June 14, 1995, indicated that the reach was stable.\nThe State Route 133 crossing of this Ira Brook Tributary is a 28-ft-long, two-lane bridge \nconsisting of one 26-foot concrete span (Vermont Agency of Transportation, written \ncommunication, March 13, 1995). The bridge is supported by vertical, concrete abutments \nwith wingwalls. The channel is skewed approximately 20 degrees to the opening while the \nopening-skew-to-roadway is 5 degrees. \nA scour hole, approximately 0.5 ft deeper than the mean thalweg depth, was observed at the \ndownstream end of the left abutment wall during the Level I assessment. The scour \nprotection measures at the site were type-1 stone fill (less than 12 inches diameter) on the \nupstream left bank and upstream left wingwall and type-2 stone fill (less than 36 inches \ndiameter) on the upstream right bank, upstream right wingwall, the downstream wingwalls \nand downstream banks. Additional details describing conditions at the site are included in \nthe Level II Summary and Appendices D and E.\nScour depths and rock rip-rap sizes were computed using the general guidelines described \nin Hydraulic Engineering Circular 18 (Richardson and others, 1995). 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.\nThere was no computed contraction scour for any of the modelled flows. Abutment scour \nranged from 3.6 to 4.7 ft. The worst-case abutment scour occurred at the 500-year \ndischarge. Additional information on scour depths and depths to armoring are included in \nthe section titled “Scour Results”. Scoured-streambed elevations, based on the calculated \nscour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the \nbridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of \nerosive material and a homogeneous particle-size distribution. \nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr96749","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Boehmler, E.M., 1996, Level II scour analysis for Bridge 13 (IRAVT013300133) on State Route 133, crossing an Ira Brook Tributary, Ira, Vermont: U.S. Geological Survey Open-File Report 96-749, iv, 47 p., https://doi.org/10.3133/ofr96749.","productDescription":"iv, 47 p.","numberOfPages":"52","costCenters":[],"links":[{"id":170317,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96749.PNG"},{"id":279580,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0749/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Ira","otherGeospatial":"Ira Brook Tributary","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -73.125,43.5 ], [ -73.125,43.625 ], [ -73.0,43.625 ], [ -73.0,43.5 ], [ -73.125,43.5 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b1ae4b07f02db6a83a0","contributors":{"authors":[{"text":"Boehmler, Erick M.","contributorId":96303,"corporation":false,"usgs":true,"family":"Boehmler","given":"Erick","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":240383,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":49865,"text":"ofr96750 - 1996 - Level II scour analysis for Bridge 9 (JAYVT02420009) on Vermont Highway 242, crossing the Jay Branch of the Missisquoi River, Jay, Vermont","interactions":[],"lastModifiedDate":"2013-12-17T12:36:37","indexId":"ofr96750","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":"96-750","title":"Level II scour analysis for Bridge 9 (JAYVT02420009) on Vermont Highway 242, crossing the Jay Branch of the Missisquoi River, Jay, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nJAY-VT02420009 on Vermont highway 242 crossing the the Jay Branch of the Missisquoi \nRiver, Jay, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the \nsite, including a quantitative analysis of stream stability and scour (U.S. Department of \nTransportation, 1993). Results of a Level I scour investigation also are included in \nAppendix E of this report. A Level I study provides a qualitative geomorphic \ncharacterization of the study site. Information on the bridge, gleaned from Vermont Agency \nof Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II \nanalyses and is found in Appendix D.\nThe site is in the Green Mountain section of the New England physiographic province of \nnorthern Vermont in the town of Jay. The 4.36-mi2\n drainage area is in a predominantly rural \nand forested basin. In the vicinity of the study site, the surface cover is primarily forest and \nbrush except for the downstream left overbank which is grass.\nIn the study area, the the Jay Branch of the Missisquoi River has an incised, sinuous channel \nwith a slope of approximately 0.021 ft/ft, an average channel top width of 38 ft and an \naverage channel depth of 5 ft. A Level I visual inspection at the site indicates that the \npredominant channel bed material is cobble and boulder with gravel. Results of a pebble \ncount indicate that the predominant channnel bed material is a very coarse gravel with a \nmedian grain size (D50) of 41.7 mm (0.1369 ft). The geomorphic assessment at the time of \nthe Level I and Level II site visit on June 6, 1995, indicated that the reach was stable.\nThe Vermont highway 242 crossing of the the Jay Branch of the Missisquoi River is a 60-\nft-long, two-lane bridge consisting of one 55-foot steel-beam span (Vermont Agency of \nTransportation, written communication, March 6, 1995). The bridge is supported by \nvertical, concrete abutments with wingwalls. The channel is skewed approximately 60 \ndegrees to the opening while the opening-skew-to-roadway is 45 degrees. \nThe scour protection measures at the site included type-2 stone fill (less than 36 inches \ndiameter) at the upstream right wingwall, the downstream left and right wingwalls and the \nupstream end of the left abutment. Type-1 stone fill (less than 12 inches) was along the \nupstream end of the right abutment. Type-4 stone fill (less than 64 inches) was along the \nupstream left wingwall. Additional details describing conditions at the site are included in \nthe Level II Summary and Appendices D and E.\nScour depths and rock rip-rap sizes were computed using the general guidelines described \nin Hydraulic Engineering Circular 18 (Richardson and others, 1995). Total scour at a \nhighway crossing is comprised of three components: 1) long-term streambed degradation; \n2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) \nand; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is \nthe sum of the three components. Equations are available to compute depths for contraction \nand local scour and a summary of the results of these computations follows.\nContraction scour for all modelled flows ranged from 0.0 to 0.6 ft. The worst-case \ncontraction scour occurred at the 100-year discharge. Abutment scour ranged from 0.8 to \n5.6 ft. The worst-case abutment scour occurred at the 500-year discharge. Additional \ninformation on scour depths and depths to armoring are included in the section titled “Scour \nResults”. Scoured streambed elevations, based on the calculated scour depths, are presented \nin tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure \n8. Scour depths were calculated assuming an infinite depth of erosive material and a \nhomogeneous particle-size distribution. \n It is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr96750","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Flynn, R.H., and Ivanoff, M.A., 1996, Level II scour analysis for Bridge 9 (JAYVT02420009) on Vermont Highway 242, crossing the Jay Branch of the Missisquoi River, Jay, Vermont: U.S. Geological Survey Open-File Report 96-750, iv, 49 p., https://doi.org/10.3133/ofr96750.","productDescription":"iv, 49 p.","numberOfPages":"54","costCenters":[],"links":[{"id":170318,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96750.PNG"},{"id":279581,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0750/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Jay","otherGeospatial":"Missisquoi River","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.5,44.875 ], [ -72.5,45.0 ], [ -72.375,45.0 ], [ -72.375,44.875 ], [ -72.5,44.875 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b16e4b07f02db6a55c0","contributors":{"authors":[{"text":"Flynn, Robert H. rflynn@usgs.gov","contributorId":2137,"corporation":false,"usgs":true,"family":"Flynn","given":"Robert","email":"rflynn@usgs.gov","middleInitial":"H.","affiliations":[{"id":405,"text":"NH/VT office of New England Water Science Center","active":true,"usgs":true}],"preferred":true,"id":240384,"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":240385,"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.

\n
\n

The 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.

\n
\n

In 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.

\n
\n

The 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.

\n
\n

Scour 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.

\n
\n

Contraction 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.

\n
\n

It 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":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.

\n
\n

The 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.

\n
\n

In 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.

\n
\n

The 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.

\n
\n

Scour 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.

\n
\n

Contraction 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.

\n
\n

It 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}]}} ]}