This report provides the results of a detailed Level II analysis of scour potential at structure \nSUNDFLR0030012 on Forest Land Road (FLR) 3 (FAS 114) crossing Roaring Branch \nBrook, Sunderland, Vermont (figures 1–8). A Level II study is a basic engineering analysis \nof the site, including a quantitative analysis of stream stability and scour (U.S. Department \nof Transportation, 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 \nsouthwestern Vermont. The 4.93-mi2\n drainage area is in a predominantly rural and forested \nbasin. In the vicinity of the study site, the surface cover is dense forest along the left bank \nand primarily shrubs and trees along the right bank, both upstream and downstream of the \nbridge.
\nIn the study area, Roaring Branch Brook has an incised, sinuous channel with a slope of \napproximately 0.01 ft/ft, an average channel top width of 33 ft and an average bank height \nof 4 ft. The channel bed material ranges from cobble to bedrock with a median grain size \n(D50) of 139 mm (0.457 ft). The geomorphic assessment at the time of the Level I and Level \nII site visit on July 30, 1996, indicated that the reach was stable.
\nForest Land Road 3 (FAS 114) crossing of Roaring Branch Brook is a 37-ft-long, two-lane \nbridge consisting of one 35-foot steel-beam span (Vermont Agency of Transportation, \nwritten communication, December 14, 1995). The bridge is supported by vertical, concrete \nabutments with wingwalls. The channel is skewed approximately 30 degrees to the opening \nwhile the opening-skew-to-roadway is 15 degrees.
\nThe scour protection measures at the site included type-3 stone fill (less than 48 inches \ndiameter) along the left and right abutments, along the upstream left and downstream right \nwing walls and along the downstream right bank. Type-4 (less than 60 inches diameter) \nstone fill was found along the upstream right and downstream left wingwalls and along the \ndownstream left bank. Type-2 (less than 36 inches diameter) stone fill scour protection was \nfound along the upstream left and right banks. 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 was calculated to be 0.0 ft. Abutment scour ranged \nfrom 4.3 to 10.4 ft. The worst-case abutment scour occurred at the 500-year discharge along \nthe right abutment. Additional information on scour depths and depths to armoring are \nincluded in the section titled “Scour Results”. Scoured-streambed elevations, based on the \ncalculated scour depths, are presented in tables 1 and 2. A cross-section of the scour \ncomputed at the bridge is presented in figure 8. Scour depths were calculated assuming an \ninfinite depth of erosive material and a homogeneous particle-size distribution.
\nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr97185","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Flynn, R.H., and Medalie, L., 1997, Level II scour analysis for Bridge 12 (SUNDFLR0030012) on Forest Land Road 3, crossing Roaring Branch Brook, Sunderland, Vermont: U.S. Geological Survey Open-File Report 97-185, iv, 48 p., https://doi.org/10.3133/ofr97185.","productDescription":"iv, 48 p.","numberOfPages":"53","costCenters":[],"links":[{"id":170022,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97185.GIF"},{"id":279812,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0185/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Sunderland","otherGeospatial":"Roaring Branch Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -73.125,43.0 ], [ -73.125,43.125 ], [ -73.0,43.125 ], [ -73.0,43.0 ], [ -73.125,43.0 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b1ae4b07f02db6a83aa","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":240428,"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":240429,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49907,"text":"ofr97218 - 1997 - Level II scour analysis for Bridge 30 (NEWFVT00300013) on Vermont Highway 30, crossing Smith Brook, Newfane, Vermont","interactions":[],"lastModifiedDate":"2014-01-06T14:30:40","indexId":"ofr97218","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-218","title":"Level II scour analysis for Bridge 30 (NEWFVT00300013) on Vermont Highway 30, crossing Smith Brook, Newfane, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nNEWFVT00300013 on State Route 30 crossing Smith Brook, Newfane, Vermont (figures \n1–8). A Level II study is a basic engineering analysis of the site, including a quantitative \nanalysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of \na Level I scour investigation also are included in Appendix E of this report. A Level I \ninvestigation provides a qualitative geomorphic characterization of the study site. \nInformation on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) \nfiles, was compiled prior to conducting Level I and Level II analyses and is found in \nAppendix D.
\nThe site is in the New England Upland section of the New England physiographic province \nin southeastern Vermont. The 9.38-mi2\n drainage area is in a predominantly rural and \nforested basin. In the vicinity of the study site, the surface cover is grass and shrubs except \nfor the upstream right bank which is forested.
\nIn the study area, Smith Brook has an incised, sinuous channel with a slope of \napproximately 0.01 ft/ft, an average channel top width of 53 ft and an average bank height \nof 5 ft. The channel bed material is predominantly cobbles with a median grain size (D50) of \n79.5 mm (0.261 ft). The geomorphic assessment at the time of the Level I and Level II site \nvisit on August 20, 1996, indicated that the reach was stable.
\nThe State Route 30 crossing of Smith Brook is a 69-ft-long, two-lane bridge consisting of \none 66-foot steel-beam span (Vermont Agency of Transportation, written communication, \nMarch 30, 1995). The bridge is supported by vertical, concrete abutments with wingwalls. \nThe channel is skewed approximately 45 degrees to the opening while the opening-skew-to-\nroadway is 55 degrees.
\nThe scour protection measures at the site were type-1 stone fill (less than 12 inches \ndiameter) along the upstream right bank. There was also type-2 stone fill (less than 36 \ninches diameter) along the upstream left bank. A stone wall extends to 72 feet upstream \nfrom the end of the upstream left wingwall. There is another stone wall along the upstream \nright bank. Additional details describing conditions at the site are included in the Level II \nSummary and Appendices D and E.
\nScour depths and recommended rock rip-rap sizes were computed using the general \nguidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995). \nTotal scour at a highway crossing is comprised of three components: 1) long-term \nstreambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction \nin flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and \nabutments). Total scour is the sum of the three components. Equations are available to \ncompute depths for contraction and local scour and a summary of the results of these \ncomputations follows.
\nContraction scour for all modelled flows ranged from 0.0 to 0.8 ft. The worst-case \ncontraction scour occurred at the 500-year discharge. Abutment scour ranged from 14.4 to \n18.2 ft. The worst-case abutment scour occurred at the 500-year discharge. Additional \ninformation on scour depths and depths to armoring are included in the section titled “Scour \nResults”. Scoured-streambed elevations, based on the calculated scour depths, are presented \nin tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure \n8. Scour depths were calculated assuming an infinite depth of erosive material and a \nhomogeneous particle-size distribution.
\nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr97218","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Ivanoff, M.A., and Medalie, L., 1997, Level II scour analysis for Bridge 30 (NEWFVT00300013) on Vermont Highway 30, crossing Smith Brook, Newfane, Vermont: U.S. Geological Survey Open-File Report 97-218, iv, 48 p., https://doi.org/10.3133/ofr97218.","productDescription":"iv, 48 p.","numberOfPages":"53","costCenters":[],"links":[{"id":169645,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97218.GIF"},{"id":279778,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0218/report.pdf"}],"scale":"25000","country":"United States","state":"Vermont","city":"Newfane","otherGeospatial":"Smith Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.75,42.875 ], [ -72.75,43.0 ], [ -72.5,43.0 ], [ -72.5,42.875 ], [ -72.75,42.875 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b19e4b07f02db6a7eb9","contributors":{"authors":[{"text":"Ivanoff, Michael A.","contributorId":27105,"corporation":false,"usgs":true,"family":"Ivanoff","given":"Michael","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":240458,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Medalie, Laura 0000-0002-2440-2149 lmedalie@usgs.gov","orcid":"https://orcid.org/0000-0002-2440-2149","contributorId":3657,"corporation":false,"usgs":true,"family":"Medalie","given":"Laura","email":"lmedalie@usgs.gov","affiliations":[{"id":466,"text":"New England Water Science Center","active":true,"usgs":true}],"preferred":true,"id":240457,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49888,"text":"ofr97183 - 1997 - Level II scour analysis for Bridge 26 (PUTNTH00010026) on Town Highway 1, crossing Sacketts Brook, Putney, Vermont","interactions":[],"lastModifiedDate":"2014-01-07T10:05:39","indexId":"ofr97183","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-183","title":"Level II scour analysis for Bridge 26 (PUTNTH00010026) on Town Highway 1, crossing Sacketts Brook, Putney, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nPUTNTH00010026 on Town Highway 1 crossing Sacketts Brook, Putney, 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 southern Vermont. The 10.1-mi2 drainage area is in a predominantly rural and forested \nbasin. In the vicinity of the study site, the surface cover is pasture upstream and downstream \nof the bridge while the immediate banks have dense woody vegetation.
\nIn the study area, Sacketts Brook has an incised, straight channel with a slope of \napproximately 0.01 ft/ft, an average channel top width of 35 ft and an average bank height \nof 5 ft. The channel bed material is predominantly cobble with a median grain size (D50) of \n68.3 mm (0.224 ft). The geomorphic assessment at the time of the Level I and Level II site \nvisit on August 20, 1996, indicated that the reach was stable.
\nThe Town Highway 1 crossing of Sacketts Brook is a 49-ft-long, two-lane bridge consisting\nof one 46-foot concrete T-beam span (Vermont Agency of Transportation, written\ncommunication, March 30, 1995). The bridge is supported by vertical, concrete abutments.\nThe channel is skewed approximately 35 degrees to the opening while the opening-skew-to-\nroadway is 45 degrees.
\nThe scour protection measure at the site was type-2 stone fill (less than 36 inches diameter) \nat the upstream end of the left abutment and along the entire base length of the right \nabutment. There was also a vertical stone wall along the upstream left bank. 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 modelled flows ranged from 0.0 to 2.7 ft. The worst-case contraction \nscour occurred at the 500-year discharge. Left abutment scour ranged from 7.9 to 9.9 ft. \nwith the worst-case occurring at the 100-year discharge. Right abutment scour ranged from \n12.6 to 17.0 ft. with the worst-case occurring at the 500-year discharge. Additional \ninformation on scour depths and depths to armoring are included in the section titled “Scour \nResults”. Scoured-streambed elevations, based on the calculated scour depths, are presented \nin tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure \n8. Scour depths were calculated assuming an infinite depth of erosive material and a \nhomogeneous particle-size distribution.
\nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 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/ofr97183","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Ivanoff, M.A., 1997, Level II scour analysis for Bridge 26 (PUTNTH00010026) on Town Highway 1, crossing Sacketts Brook, Putney, Vermont: U.S. Geological Survey Open-File Report 97-183, iv, 50 p., https://doi.org/10.3133/ofr97183.","productDescription":"iv, 50 p.","numberOfPages":"55","costCenters":[],"links":[{"id":170020,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97183.GIF"},{"id":279814,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0183/report.pdf"}],"scale":"25000","country":"United States","state":"Vermont","city":"Putney","otherGeospatial":"Sacketts Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.75,42.875 ], [ -72.75,43.125 ], [ -72.5,43.125 ], [ -72.5,42.875 ], [ -72.75,42.875 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b1ae4b07f02db6a8018","contributors":{"authors":[{"text":"Ivanoff, Michael A.","contributorId":27105,"corporation":false,"usgs":true,"family":"Ivanoff","given":"Michael","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":240425,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":49887,"text":"ofr97182 - 1997 - Level II scour analysis for Bridge 4 (ARLITH00010004) on Town Highway 1, crossing Warm Brook, Arlington, Vermont","interactions":[],"lastModifiedDate":"2014-01-07T10:30:16","indexId":"ofr97182","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-182","title":"Level II scour analysis for Bridge 4 (ARLITH00010004) on Town Highway 1, crossing Warm Brook, Arlington, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nARLITH00010004 on Town Highway 1 crossing Warm Brook, Arlington, 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 \nsouthwestern Vermont. The 12.1-mi2\n drainage area consists of a predominantly rural and \nforested basin. In the vicinity of the study site, the surface cover is brush except for the \nupstream and downstream right banks which are covered by brush and grass.
\nIn the study area, Warm Brook has an incised, straight channel with a slope of \napproximately 0.003 ft/ft, an average channel top width of 19 ft and an average bank height \nof 1 ft. The channel bed material ranges from sand to cobble with a median grain size (D50) \nof 33.3 mm (0.109 ft). The geomorphic assessment at the time of the Level I and Level II \nsite visit on July 30, 1996, indicated that the reach was stable.
\nThe Town Highway 1 crossing of Warm Brook is a 49-ft-long, two-lane bridge consisting \nof one 44-foot steel-beam span (Vermont Agency of Transportation, written \ncommunication, January 30, 1996). The bridge is supported by vertical, concrete abutments \nwith wingwalls. The abutments have been placed on top of the previous stone abutments. \nThe channel is skewed approximately 0 degrees to the opening while the opening-skew-to-\nroadway is 20 degrees.
\nA scour hole approximately 1.0 ft deeper than the mean thalweg depth was observed mid-\nchannel in the upstream reach within 30 ft of the bridge. The only scour protection measure \nat the site was type-2 stone fill (less than 36 inches diameter) along the upstream left bank \napproach to the bridge. 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 1.7 ft. The worst-case \ncontraction scour occurred at the 500-year discharge. Abutment scour ranged from 8.3 to \n11.9 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/ofr97182","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Olson, S.A., and Ivanoff, M.A., 1997, Level II scour analysis for Bridge 4 (ARLITH00010004) on Town Highway 1, crossing Warm Brook, Arlington, Vermont: U.S. Geological Survey Open-File Report 97-182, iv, 51 p., https://doi.org/10.3133/ofr97182.","productDescription":"iv, 51 p.","numberOfPages":"56","costCenters":[],"links":[{"id":170173,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97182.GIF"},{"id":279815,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0182/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Arlington","otherGeospatial":"Warm Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -73.25,43.0 ], [ -73.25,43.125 ], [ -73.125,43.125 ], [ -73.125,43.0 ], [ -73.25,43.0 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a6221","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":240423,"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":240424,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49886,"text":"ofr97111 - 1997 - Level II scour analysis for Bridge 5C (CORITH0003005C) on Town Highway 3, crossing Cooksville Brook, Corinth, Vermont","interactions":[],"lastModifiedDate":"2014-01-07T10:38:37","indexId":"ofr97111","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-111","title":"Level II scour analysis for Bridge 5C (CORITH0003005C) on Town Highway 3, crossing Cooksville Brook, Corinth, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nCORITH0003005C on Town Highway 3 crossing Cooksville Brook, Corinth, 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 20.2-mi2 drainage area is in a predominantly rural and forested \nbasin. In the vicinity of the study site, the surface cover is pasture with a residence on the \nupstream right bank near the bridge. The immediate channel banks have some woody \nvegetation cover.
\nIn the study area, Cooksville Brook has an incised, sinuous channel with a slope of \napproximately 0.005 ft/ft, an average channel top width of 46 ft and an average channel \ndepth of 8 ft. The channel bed material ranged from sand to cobble and had a median grain \nsize (D50) of 41.0 mm (0.135 ft). The geomorphic assessment at the time of the Level I and \nLevel II site visit on September 5, 1995, indicated that the reach was stable.
\nThe Town Highway 3 crossing of Cooksville Brook is a 39-ft-long, two-lane bridge \nconsisting of one 37-foot steel-beam span (Vermont Agency of Transportation, written \ncommunication, March 17, 1995). The bridge is supported by vertical, concrete abutments \nwith wingwalls on the left abutment. The channel is skewed approximately 30 degrees to \nthe opening while the opening-skew-to-roadway is 0 degrees.
\nA scour hole 0.5 ft deeper than the mean thalweg depth was observed along the right \nabutment during the Level I assessment. The only scour protection measures at the site were \ntype-2 stone fill (less than 36 inches diameter) at the upstream and downstream ends of the \nright abutment and type-4 (less than 60 inches diameter) along the upstream right bank \nbelow the residence. Also, there is a wall along the upstream right bank. 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 2.7 to 3.3 ft. The worst-case \ncontraction scour occurred at the 500-year discharge. Abutment scour ranged from 7.0 to \n19.0 ft. The worst-case left abutment scour occurred at the incipient overtopping discharge. \nThe worst-case right abutment scour occurred at the 500-year discharge. Additional \ninformation on scour depths and depths to armoring are included in the section titled “Scour \nResults”. Scoured-streambed elevations, based on the calculated scour depths, are presented \nin tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure \n8. Scour depths were calculated assuming an infinite depth of erosive material and a \nhomogeneous particle-size distribution.
\nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr97111","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Ivanoff, M.A., and Severance, T., 1997, Level II scour analysis for Bridge 5C (CORITH0003005C) on Town Highway 3, crossing Cooksville Brook, Corinth, Vermont: U.S. Geological Survey Open-File Report 97-111, iv, 50 p., https://doi.org/10.3133/ofr97111.","productDescription":"iv, 50 p.","numberOfPages":"55","costCenters":[],"links":[{"id":170112,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97111.GIF"},{"id":279816,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0111/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Corinth","otherGeospatial":"Cooksville Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.375,44.0 ], [ -72.375,44.125 ], [ -72.25,44.125 ], [ -72.25,44.0 ], [ -72.375,44.0 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a5a1c","contributors":{"authors":[{"text":"Ivanoff, Michael A.","contributorId":27105,"corporation":false,"usgs":true,"family":"Ivanoff","given":"Michael","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":240421,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Severance, Tim","contributorId":53851,"corporation":false,"usgs":true,"family":"Severance","given":"Tim","affiliations":[],"preferred":false,"id":240422,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49885,"text":"ofr97110 - 1997 - Level II scour analysis for Bridge 13 (PFRDTH00030013) on Town Highway 3, crossing Furnace Brook, Pittsford, Vermont","interactions":[],"lastModifiedDate":"2014-01-07T10:47:52","indexId":"ofr97110","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-110","title":"Level II scour analysis for Bridge 13 (PFRDTH00030013) on Town Highway 3, crossing Furnace Brook, Pittsford, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nPFRDTH00030013 on Town Highway 3 crossing Furnace Brook, Pittsford, 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 western \nVermont. The 17.1-mi2\n drainage area is in a predominantly rural and forested basin. In the \nvicinity of the study site, the surface cover is grass along the downstream right bank while \nthe remaining banks are primarily forested.
\nIn the study area, Furnace Brook has an incised, sinuous channel with a slope of \napproximately 0.03 ft/ft, an average channel top width of 49 ft and an average channel \ndepth of 4 ft. The predominant channel bed material ranges from gravel to bedrock with a \nmedian grain size (D50) of 70.2 mm (0.230 ft). The geomorphic assessment at the time of \nthe Level I and Level II site visit on June 20, 1995, indicated that the reach was stable.
\nThe Town Highway 3 crossing of Furnace Brook is a 75-ft-long, two-lane bridge consisting \nof one 72-ft-long steel stringer span (Vermont Agency of Transportation, written \ncommunication, March 14, 1995). The bridge is supported by vertical, concrete abutments \nwith spill-through slopes. The channel is skewed approximately 20 degrees to the opening \nwhile the opening-skew-to-roadway is 35 degrees. The opening-skew-to-roadway was \ndetermined from surveyed data collected at the bridge although, information provided from \nthe VTAOT files, indicates that the opening-skew-to-roadway is 30 degrees (Appendix D).
\nThe scour protection measures at the site included type-2 stone fill (less than 36 inches \ndiameter) on the spill-through slope along each abutment. Type-2 stone fill scour protection \nwas also found along the upstream left wingwall and downstream right wingwall. Type-1 \n(less than 12 inches diameter) stone fill scour protection was found along the upstream right \nwingwall and downstream left wingwall. No bank protection was observed downstream or \nupstream. 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 1.2 to 2.0 ft. The worst-case \ncontraction scour occurred at the 500-year discharge. Abutment scour ranged from 7.8 to \n13.1 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 although, bedrock outcropping is apparent both \nupstream and downstream of this bridge.
\nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr97110","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Flynn, R.H., and Medalie, L., 1997, Level II scour analysis for Bridge 13 (PFRDTH00030013) on Town Highway 3, crossing Furnace Brook, Pittsford, Vermont: U.S. Geological Survey Open-File Report 97-110, iv, 50 p., https://doi.org/10.3133/ofr97110.","productDescription":"iv, 50 p.","numberOfPages":"55","costCenters":[],"links":[{"id":170111,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97110.GIF"},{"id":279817,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0110/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Pittsford","otherGeospatial":"Furnace Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -73.125,43.625 ], [ -73.125,43.75 ], [ -72.875,43.75 ], [ -72.875,43.625 ], [ -73.125,43.625 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b1ae4b07f02db6a8321","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":240419,"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":240420,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49884,"text":"ofr97109 - 1997 - Level II scour analysis for Bridge 9 (BARRUSO3020009) on U.S. Route 302, crossing Jail Branch, Barre, Vermont","interactions":[],"lastModifiedDate":"2014-01-07T10:59:16","indexId":"ofr97109","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-109","title":"Level II scour analysis for Bridge 9 (BARRUSO3020009) on U.S. Route 302, crossing Jail Branch, Barre, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nBARRUS03020009 on U.S. Route 302 crossing Jail Branch, Barre, Vermont (figures 1–8). \nA Level II study is a basic engineering analysis of the site, including a quantitative analysis \nof stream stability and scour (U.S. Department of Transportation, 1993). Results of a Level \nI scour investigation also are included in Appendix E of this report. A Level I investigation \nprovides a qualitative geomorphic characterization of the study site. Information on the \nbridge, 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 \nin central Vermont. The 42.8-mi2\n drainage area is in a predominantly rural and forested \nbasin. A flood control reservoir with a usable capacity of 525 million cubic feet is located \njust upstream of the bridge. In the vicinity of the study site, the surface cover left of the \nchannel consists of trees and brush. Right of the channel, the immediate bank is covered by \ntrees and brush while the overbank is grass covered with several buildings.
\nIn the study area, Jail Branch has an incised, sinuous channel with a slope of approximately \n0.008 ft/ft, an average channel top width of 86 ft and an average channel depth of 5 ft. The \nchannel bed material ranged from gravel to boulder with a median grain size (D50) of 73.5 \nmm (0.241 ft). The geomorphic assessment at the time of the Level I and Level II site visit \non July 17, 1996, indicated that the reach was laterally unstable due to its sinuosity, cut \nbanks, point bars, and extensive bank protection.
\nThe U.S. Route 302 crossing of Jail Branch is a 74-ft-long, two-lane bridge consisting of \none 72-foot steel-beam span (Vermont Agency of Transportation, written communication, \nOctober 13, 1995). The bridge is supported by vertical, concrete abutments with wingwalls. \nThe channel is skewed approximately 30 degrees to the opening while there is no opening-\nskew-to-roadway.
\nThere is evidence of channel scour along the right bank from 190 feet upstream of the \nbridge and extending through the bridge along the right abutment. Under the bridge, the \nscour depth is approximately 0.5 feet below the mean thalweg depth. Scour protection \nmeasures at the site include type-3 stone fill (less than 48 inches diameter) along the right \nbank extending from the bridge to 192 feet upstream. Type-2 stone fill (less than 36 inches \ndiameter) is along the right abutment and the right downstream bank to 205 feet downtream \nof the bridge. 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 0.2 to 0.5 ft. The worst-case \ncontraction scour occurred at the 500-year discharge. Abutment scour ranged from 4.3 to \n7.5 ft. The worst-case abutment scour occurred at the 500-year discharge. Computed scour \nfor the 100-year event does not go below the abutment footings. 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/ofr97109","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Olson, S.A., and Ivanoff, M.A., 1997, Level II scour analysis for Bridge 9 (BARRUSO3020009) on U.S. Route 302, crossing Jail Branch, Barre, Vermont: U.S. Geological Survey Open-File Report 97-109, iv, 48 p., https://doi.org/10.3133/ofr97109.","productDescription":"iv, 48 p.","numberOfPages":"53","costCenters":[],"links":[{"id":170110,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97109.GIF"},{"id":279818,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0109/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Barre","otherGeospatial":"Jail Branch","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.5,44.125 ], [ -72.5,44.25 ], [ -72.375,44.25 ], [ -72.375,44.125 ], [ -72.5,44.125 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b16e4b07f02db6a55f3","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":240417,"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":240418,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49883,"text":"ofr97108 - 1997 - Level II scour analysis for Bridge 12 (FFIETH00030012) on Town Highway 3, crossing the Fairfield River, Fairfield, Vermont","interactions":[],"lastModifiedDate":"2014-01-07T11:15:15","indexId":"ofr97108","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-108","title":"Level II scour analysis for Bridge 12 (FFIETH00030012) on Town Highway 3, crossing the Fairfield River, Fairfield, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nFFIETH00030012 on Town Highway 3 crossing the Fairfield River, Fairfield, 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-western Vermont. The 7.34-mi2 drainage area is in a predominantly rural basin with \nforest on the valley walls and pasture/row crops on the valley bottom. In the vicinity of the \nstudy site, the surface cover is row crops with a few trees on the immediate banks.
\nIn the study area, the Fairfield River has a meandering channel with a slope of \napproximately 0.005 ft/ft, an average channel top width of 37 ft and an average channel \ndepth of 6 ft. The predominant channel bed materials are sand and gravel with a median \ngrain size (D50) of 32.5 mm (0.107 ft). The geomorphic assessment at the time of the Level \nI and Level II site visit on June 16, 1995, indicated that the reach was stable.
\nThe Town Highway 3 crossing of the Fairfield River is a 24-ft-long, one-lane bridge \nconsisting of one 20-foot concrete 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 40 degrees to the opening. Although \nbridge records show an opening-skew-to-roadway of 45 degrees, the skew measured from \nsurveyed points was 30 degrees.
\nAt the time of the level I assessment, the left abutment had been undermined and settled \ninto a scour hole at the upstream end. The right abutment footing was exposed but not \nundermined. The scour protection measures at the site were type-1 stone fill (less than 12 \ninches diameter) on the downstream right bank, and type-2 stone fill (less than 36 inches \ndiameter) along the entire base of the upstream right wingwall, the upstream banks, and\ndownstream left bank. The type-2 stone fill on the left bank downstream changes to type-1 \nabout 55 feet downstream of the bridge. 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 1.6 to 3.0 ft. The worst-case \ncontraction scour occurred at the 500-year discharge. Abutment scour ranged from 3.2 to \n4.0 ft. at the left abutment and 9.7 to 11.7 feet at the right abutment. The worst-case left \nabutment scour occurred at the incipient over-topping discharge, which was less than the \n100-year discharge. The worst-case right 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/ofr97108","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Boehmler, E.M., and Degnan, J.R., 1997, Level II scour analysis for Bridge 12 (FFIETH00030012) on Town Highway 3, crossing the Fairfield River, Fairfield, Vermont: U.S. Geological Survey Open-File Report 97-108, iv, 52 p., https://doi.org/10.3133/ofr97108.","productDescription":"iv, 52 p.","numberOfPages":"57","costCenters":[],"links":[{"id":170109,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97108.GIF"},{"id":279819,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0108/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Fairfield","otherGeospatial":"Fairfield River","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -73.0,44.75 ], [ -73.0,44.875 ], [ -72.875,44.875 ], [ -72.875,44.75 ], [ -73.0,44.75 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b1ae4b07f02db6a83cc","contributors":{"authors":[{"text":"Boehmler, Erick M.","contributorId":96303,"corporation":false,"usgs":true,"family":"Boehmler","given":"Erick","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":240416,"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":240415,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49908,"text":"ofr97225 - 1997 - Level II scour analysis for Bridge 27 (ANDOTH00290027) on Town Highway 29, crossing Middle Branch Williams River, Andover, Vermont","interactions":[],"lastModifiedDate":"2014-01-05T13:56:45","indexId":"ofr97225","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-225","title":"Level II scour analysis for Bridge 27 (ANDOTH00290027) on Town Highway 29, crossing Middle Branch Williams River, Andover, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nANDOTH00290027 on Town Highway 29 crossing the Middle Branch Williams River, \nAndover, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, \nincluding a quantitative analysis of stream stability and scour (U.S. Department of \nTransportation, 1993). Results of a Level I scour investigation also are included in \nAppendix E of this report. A Level I investigation provides a qualitative geomorphic \ncharacterization of the study site. Information on the bridge, gleaned from Vermont Agency \nof Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II \nanalyses and is found in Appendix D.
\nThe site is in the Green Mountain section of the New England physiographic province in \ncentral Vermont. The 12.7-mi2\n drainage area is in a predominantly rural and forested basin. \nIn the vicinity of the study site, the surface cover is pasture on the left bank upstream of the \nbridge while the immediate bank has woody vegetation. The surface cover on the upstream \nright bank is forest. Downstream of the bridge the left bank is pasture and the right bank \nhas woody vegetation.
\nIn the study area, the Middle Branch Williams River has an incised, straight channel with a \nslope of approximately 0.009 ft/ft, an average channel top width of 63 ft and an average \nbank height of 5 ft. The channel bed material ranges from sand to cobble with a median \ngrain size (D50) of 64.7 mm (0.212 ft). The geomorphic assessment at the time of the Level \nI and Level II site visit on September 10, 1996, indicated that the reach was stable.
\nThe Town Highway 29 crossing of the Middle Branch Williams River is a 34-ft-long, two-\nlane bridge consisting of one 32-foot steel-beam span (Vermont Agency of Transportation, \nwritten communication, April 5, 1995). The bridge is supported by vertical, concrete \nabutments with wingwalls. The channel is skewed approximately 25 degrees to the opening \nwhile the opening-skew-to-roadway is 0 degrees.
\nA scour hole 1.5 ft deeper than the mean thalweg depth was observed along the left \nabutment during the Level I assessment. Scour protection measures at the site include type-\n2 stone fill (less than 36 inches diameter) along the upstream right bank and downstream \nleft bank and around the upstream left and right wingwalls. Type- 3 stone fill (less than 48 \ninches diameter) is located along the base of the left abutment in the scour hole, at the end \nof the downstream left wingwall and along the upstream left bank. Additional details \ndescribing conditions at the site are included in the Level II Summary and Appendices D \nand E.
\nScour depths and recommended rock rip-rap sizes were computed using the general \nguidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995). \nTotal scour at a highway crossing is comprised of three components: 1) long-term \nstreambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction \nin flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and \nabutments). Total scour is the sum of the three components. Equations are available to \ncompute depths for contraction and local scour and a summary of the results of these \ncomputations follows.
\nContraction scour for all modelled flows ranged from 0.4 to 0.9 ft. The worst-case \ncontraction scour occurred at the incipient-overtopping discharge and the 100-year \ndischarge. Abutment scour ranged from 10.7 to 13.6 ft. The worst-case abutment scour \noccurred at the 500-year discharge. Additional information on scour depths and depths to \narmoring are included in the section titled “Scour Results”. Scoured-streambed elevations, \nbased on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the \nscour computed at the bridge is presented in figure 8. Scour depths were calculated \nassuming an infinite depth of erosive material and a homogeneous particle-size distribution.
\nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr97225","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Burns, R.L., and Wild, E.C., 1997, Level II scour analysis for Bridge 27 (ANDOTH00290027) on Town Highway 29, crossing Middle Branch Williams River, Andover, Vermont: U.S. Geological Survey Open-File Report 97-225, iv, 50 p., https://doi.org/10.3133/ofr97225.","productDescription":"iv, 50 p.","numberOfPages":"55","costCenters":[],"links":[{"id":169646,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97225.GIF"},{"id":279775,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0225/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Andover","otherGeospatial":"Middle Branch Williams River","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.75,43.25 ], [ -72.75,43.375 ], [ -72.625,43.375 ], [ -72.625,43.25 ], [ -72.75,43.25 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b1ae4b07f02db6a7ffe","contributors":{"authors":[{"text":"Burns, Ronda L.","contributorId":71602,"corporation":false,"usgs":true,"family":"Burns","given":"Ronda","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":240460,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Wild, Emily C. 0000-0001-6157-7629 ecwild@usgs.gov","orcid":"https://orcid.org/0000-0001-6157-7629","contributorId":1810,"corporation":false,"usgs":true,"family":"Wild","given":"Emily","email":"ecwild@usgs.gov","middleInitial":"C.","affiliations":[{"id":5081,"text":"Libraries","active":false,"usgs":true}],"preferred":false,"id":240459,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49909,"text":"ofr97226 - 1997 - Level II scour analysis for Bridge 12 (HUNTTH00010012) on Town Highway 001, crossing Brush Brook, Huntington, Vermont","interactions":[],"lastModifiedDate":"2014-01-06T11:07:06","indexId":"ofr97226","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-226","title":"Level II scour analysis for Bridge 12 (HUNTTH00010012) on Town Highway 001, crossing Brush Brook, Huntington, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nHUNTTH00010012 on Town Highway 1 crossing Brush Brook, Huntington, Vermont \n(figures 1–9). A Level II study is a basic engineering analysis of the site, including a \nquantitative analysis of stream stability and scour (U.S. Department of Transportation, \n1993). Results of a Level I scour investigation also are included in Appendix E of this \nreport. A Level I investigation provides a qualitative geomorphic characterization of the \nstudy site. Information on the bridge, gleaned from Vermont Agency of Transportation \n(VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is \nfound in Appendix D.
\nIn August 1976, Hurricane Belle caused flooding at this site which resulted in road and \nbridge damage (figures 7-8). This was approximately a 25-year flood event based on flood-\nfrequency data contained in the Flood Insurance Study for the Town of Huntington (U.S. \nDepartment of Housing and Urban Development, 1978).
\nThe site is in the Green Mountain section of the New England physiographic province in \ncentral Vermont. The 9.19-mi2\n drainage area is in a predominantly rural and forested basin. \nIn the vicinity of the study site, the surface cover is pasture while the immediate banks have \nsome woody vegetation.
\nIn the study area, the Brush Brook has a sinuous channel with a slope of approximately 0.02 \nft/ft, an average channel top width of 62 ft and an average bank height of 5 ft. The channel \nbed material ranges from gravel to cobble with a median grain size (D50) of 100.0 mm \n(0.328 ft). The geomorphic assessment at the time of the Level I and Level II site visit on \nJune 25, 1996, indicated that the reach was stable.
\nThe Town Highway 1 crossing of Brush Brook is a 64-ft-long, two-lane bridge consisting of \none 62-foot steel-stringer span (Vermont Agency of Transportation, written \ncommunication, November 30, 1995). The bridge is supported by vertical, concrete \nabutments with wingwalls. The channel is skewed approximately 10 degrees to the opening \nwhile the opening-skew-to-roadway is 6 degrees.
\nChannel scour 2.2 ft deeper than the mean thalweg depth was observed along the upstream \nright bank and along the base of the spill-through protection for the right abutment during \nthe Level I assessment. Scour protection measured at the site was type-2 stone fill (less \nthan 36 inches diameter) along the upstream left and right banks and in front of all four \nwingwalls. In front of the abutments, there was type-3 stone fill (less than 48 inches \ndiameter) forming a spill-through slope. Additional details describing conditions at the site \nare included in the Level II Summary and Appendices D and E.
\nScour depths and recommended rock rip-rap sizes were computed using the general \nguidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995). \nTotal scour at a highway crossing is comprised of three components: 1) long-term \nstreambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction \nin flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and \nabutments). Total scour is the sum of the three components. Equations are available to \ncompute depths for contraction and local scour and a summary of the results of these \ncomputations follows.
\nThere was no computed contraction scour for any modelled flow. Abutment scour ranged \nfrom 1.4 to 2.8 ft. The worst-case abutment scour occurred at the 500-year discharge. \nAdditional information on scour depths and depths to armoring are included in the section \ntitled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, \nare presented in tables 1 and 2. A cross-section of the scour computed at the bridge is \npresented in figure 9. Scour depths were calculated assuming an infinite depth of erosive \nmaterial and a homogeneous particle-size distribution.
\nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr97226","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Burns, R.L., and Wild, E.C., 1997, Level II scour analysis for Bridge 12 (HUNTTH00010012) on Town Highway 001, crossing Brush Brook, Huntington, Vermont: U.S. Geological Survey Open-File Report 97-226, iv, 49 p., https://doi.org/10.3133/ofr97226.","productDescription":"iv, 49 p.","numberOfPages":"54","costCenters":[],"links":[{"id":169718,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97226.GIF"},{"id":279777,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0226/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Huntington","otherGeospatial":"Brush Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -73.0,44.25 ], [ -73.0,44.375 ], [ -72.875,44.375 ], [ -72.875,44.25 ], [ -73.0,44.25 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b1ae4b07f02db6a83b3","contributors":{"authors":[{"text":"Burns, Ronda L.","contributorId":71602,"corporation":false,"usgs":true,"family":"Burns","given":"Ronda","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":240462,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Wild, Emily C. 0000-0001-6157-7629 ecwild@usgs.gov","orcid":"https://orcid.org/0000-0001-6157-7629","contributorId":1810,"corporation":false,"usgs":true,"family":"Wild","given":"Emily","email":"ecwild@usgs.gov","middleInitial":"C.","affiliations":[{"id":5081,"text":"Libraries","active":false,"usgs":true}],"preferred":false,"id":240461,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49914,"text":"ofr97342 - 1997 - Level II scour analysis for Bridge 43 (CHESVT00110043) on State Highway 11, crossing the Middle Branch Williams River, Chester, Vermont","interactions":[],"lastModifiedDate":"2014-01-05T13:14:13","indexId":"ofr97342","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-342","title":"Level II scour analysis for Bridge 43 (CHESVT00110043) on State Highway 11, crossing the Middle Branch Williams River, Chester, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nCHESVT00110043 on State Route 11 crossing the Middle Branch of the Williams River, \nChester, 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 principally in the Green Mountain section of the New England physiographic \nprovince in southeastern Vermont. The 13.7-mi2\n drainage area is in a predominantly rural \nand forested basin. In the vicinity of the study site, the surface cover is predominantly forest \nexcept for the area downstream and right of the bridge which is pasture.
\nIn the study area, the Middle Branch of the Williams River has a sinuous channel with a \nslope of approximately 0.01 ft/ft, an average channel top width of 77 ft and an average bank \nheight of 8 ft. The channel bed material ranges from gravel to boulder with a median grain \nsize (D50) of 76.6 mm (0.251 ft). The geomorphic assessment at the time of the Level I and \nLevel II site visit on September 11, 1996, indicated that the reach was laterally unstable. \nLateral instability was evident from the several point bars and cut banks located through the \nstudy reach.
\nThe State Route 11 crossing of the Middle Branch of the Williams River is a\n76-ft-long, two-lane bridge consisting of two 37-foot concrete Tee-beam spans (Vermont \nAgency of Transportation, written communication, March 29, 1995). The bridge is \nsupported by vertical, concrete abutments with wingwalls. The channel is skewed \napproximately 35 degrees to the opening. The computed opening-skew-to-roadway was 30 \ndegrees but the historical records indicate this angle is 25 degrees.
\nScour protection measures at the site consist of type-1 stone fill (less than 12 inches \ndiameter) along the downstream banks and the upstream right wing wall. Type-2 (less than \n36 inches diameter) stone fill protection is noted on the upstream and downstream left \nwingwalls and upstream along the left bank. Additional details describing conditions at the \nsite are included in the Level II Summary and Appendices D and E.
\nScour depths and recommended rock rip-rap sizes were computed using the general \nguidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995). \nTotal scour at a highway crossing is comprised of three components: 1) long-term \nstreambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction \nin flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and \nabutments). Total scour is the sum of the three components. Equations are available to \ncompute depths for contraction and local scour and a summary of the results of these \ncomputations follows.
\nContraction scour for all modelled flows ranged from 0.0 to 1.5 ft. The worst-case \ncontraction scour occurred at the 500-year discharge. Abutment scour ranged from 7.2 to \n10.7 ft. The worst-case abutment scour occurred at the 500-year discharge for the right \nabutment. Pier scour ranged from 7.3 to 8.6 ft. The worst-case pier scour occurred at the \n500-year discharge. Additional information on scour depths and depths to armoring are \nincluded in the section titled “Scour Results”. Scoured-streambed elevations, based on the \ncalculated scour depths, are presented in tables 1 and 2. A cross-section of the scour \ncomputed at the bridge is presented in figure 8. Scour depths were calculated assuming an \ninfinite depth of erosive material and a homogeneous particle-size distribution.
\nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr97342","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Striker, L.K., and Burns, R.L., 1997, Level II scour analysis for Bridge 43 (CHESVT00110043) on State Highway 11, crossing the Middle Branch Williams River, Chester, Vermont: U.S. Geological Survey Open-File Report 97-342, iv, 50 p., https://doi.org/10.3133/ofr97342.","productDescription":"iv, 50 p.","numberOfPages":"55","costCenters":[],"links":[{"id":169723,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/usgs_thumb.jpg"},{"id":279771,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0342/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Chester","otherGeospatial":"Williams River","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.75,43.25 ], [ -72.75,43.375 ], [ -72.625,43.375 ], [ -72.625,43.25 ], [ -72.75,43.25 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a614c","contributors":{"authors":[{"text":"Striker, Lora K.","contributorId":41481,"corporation":false,"usgs":true,"family":"Striker","given":"Lora","email":"","middleInitial":"K.","affiliations":[],"preferred":false,"id":240468,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Burns, Ronda L.","contributorId":71602,"corporation":false,"usgs":true,"family":"Burns","given":"Ronda","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":240469,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49881,"text":"ofr97106 - 1997 - Level II scour analysis for Bridge 11 (HINETH00040011) on Town Highway 4, crossing Lewis Creek, Hinesburg, Vermont","interactions":[],"lastModifiedDate":"2014-01-07T11:35:22","indexId":"ofr97106","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-106","title":"Level II scour analysis for Bridge 11 (HINETH00040011) on Town Highway 4, crossing Lewis Creek, Hinesburg, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nHINETH00040011 on Town Highway 4 crossing Lewis Creek, Hinesburg, 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 \nnorthwestern Vermont. The 38.4-mi2 drainage area is in a predominantly rural and forested \nbasin. In the vicinity of the study site, the surface cover is pasture.
\nIn the study area, Lewis Creek has an incised, straight channel with a slope of \napproximately 0.001 ft/ft, an average channel top width of 60 ft and an average channel \ndepth of 7 ft. The channel bed material ranges from gravel to boulder with a median grain \nsize (D50) of 47.0 mm (0.154 ft). The geomorphic assessment at the time of the Level I and \nLevel II site visit on July 3, 1996, indicated that the reach was stable.
\nThe Town Highway 4 crossing of Lewis Creek is an 84-foot-long, two-lane bridge \nconsisting of one 82-foot steel-beam span (Vermont Agency of Transportation, written \ncommunication, December 15, 1995). The bridge is supported by vertical, concrete \nabutments with wingwalls and spill-through embankments at each abutment. The channel is \nskewed approximately 40 degrees to the opening while the opening-skew-to-roadway is 15 \ndegrees.
\nThe scour protection measures at the site were type-2 stone fill (less than 36 inches \ndiameter) at the downstream left and right wingwalls and the downstream right bank. Scour \nprotection also included type-3 stone fill (less than 48 inches diameter) at the left and right \nupstream wingwalls, both abutments, both upstream banks, and the left bank downstream. \nAdditional details describing conditions at the site are included in the Level II Summary \nand Appendices D and E.
\nScour depths and rock rip-rap sizes were computed using the general guidelines described \nin Hydraulic Engineering Circular 18 (Richardson and others, 1995). Total scour at a \nhighway crossing is comprised of three components: 1) long-term streambed degradation; \n2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) \nand; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is \nthe sum of the three components. Equations are available to compute depths for contraction \nand local scour and a summary of the results of these computations follows.
\nContraction scour for all modelled flows ranged from 0.0 to 1.8 ft. The worst-case \ncontraction scour occurred at the 500-year discharge. Left abutment scour ranged from \n14.1 to 18.2 ft. Right abutment scour ranged from 9.9 to 13.4 ft. The worst-case abutment \nscour occurred at left abutment for the 500-year discharge. Additional information on scour \ndepths and depths to armoring are included in the section titled “Scour Results”. Scoured-\nstreambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. \nA cross-section of the scour computed at the bridge is presented in figure 8. Scour depths \nwere calculated assuming an infinite depth of erosive material and a homogeneous particle-\nsize distribution.
\nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr97106","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Ivanoff, M.A., and Burns, R.L., 1997, Level II scour analysis for Bridge 11 (HINETH00040011) on Town Highway 4, crossing Lewis Creek, Hinesburg, Vermont: U.S. Geological Survey Open-File Report 97-106, iv, 48 p., https://doi.org/10.3133/ofr97106.","productDescription":"iv, 48 p.","numberOfPages":"53","costCenters":[],"links":[{"id":170107,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97106.GIF"},{"id":279821,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0106/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Hinesburg","otherGeospatial":"Lewis Creek","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -73.125,44.25 ], [ -73.125,44.375 ], [ -73.0,44.375 ], [ -73.0,44.25 ], [ -73.125,44.25 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b1ae4b07f02db6a840a","contributors":{"authors":[{"text":"Ivanoff, Michael A.","contributorId":27105,"corporation":false,"usgs":true,"family":"Ivanoff","given":"Michael","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":240412,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Burns, Ronda L.","contributorId":71602,"corporation":false,"usgs":true,"family":"Burns","given":"Ronda","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":240413,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49880,"text":"ofr97105 - 1997 - Level II scour analysis for Bridge 6 (MORRTH00030006) on Town Highway 3, crossing Ryder Brook, Morristown, Vermont","interactions":[],"lastModifiedDate":"2014-01-07T11:42:39","indexId":"ofr97105","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-105","title":"Level II scour analysis for Bridge 6 (MORRTH00030006) on Town Highway 3, crossing Ryder Brook, Morristown, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nMORRTH00030006 on Town Highway 3 crossing Ryder Brook, Morristown, Vermont \n(figures 1–8). A Level II study is a basic engineering analysis of the site, including a \nquantitative analysis of stream stability and scour (U.S. Department of Transportation, \n1993). Results of a Level I scour investigation also are included in Appendix E of this \nreport. A Level I investigation provides a qualitative geomorphic characterization of the \nstudy site. Information on the bridge, gleaned from Vermont Agency of Transportation \n(VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is \nfound in Appendix D.
\nThe site is in the Green Mountain section of the New England physiographic province in \nnorth-central Vermont. The 19.1-mi2 drainage area is in a predominantly rural and forested \nbasin. In the vicinity of the study site, the surface cover also is forested.
\nIn the study area, Ryder Brook has a straight channel with an average channel top width of \n450 ft and an average bank height of 7 ft. The predominant channel bed material is silt and \nclay with a median grain size (D50) of 0.0719 mm (0.000236 ft). The geomorphic \nassessment at the time of the Level I and Level II site visit on July 18, 1996, indicated that \nthe reach was aggraded, but the channel through the bridge was scoured.
\nThe Town Highway 3 crossing of Ryder Brook is a 72-ft-long, two-lane bridge consisting \nof one 70-foot steel-beam span (Vermont Agency of Transportation, written \ncommunication, January 31, 1996). The bridge is supported by vertical, concrete abutments \nwith spill-through embankments and wingwalls. The channel is not skewed to the opening \nand the opening-skew-to-roadway is zero degrees.
\nChannel scour under the bridge was evident at this site during the Level I assessment. The \ndepth of the channel increases from 3 feet at the upstream bridge face to 10 feet at the \ndownstream bridge face. The only scour protection measure at the site was type-2 stone fill \n(less than 36 inches diameter) on the spill-through embankments of each abutment, the \nupstream road embankments and the downstream left road embankment. 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 20.4 to 25.8 ft. The worst-case \ncontraction scour occurred at the 500-year discharge. Abutment scour ranged from 8.3 to \n10.5 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/ofr97105","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Boehmler, E.M., and Hammond, R.E., 1997, Level II scour analysis for Bridge 6 (MORRTH00030006) on Town Highway 3, crossing Ryder Brook, Morristown, Vermont: U.S. Geological Survey Open-File Report 97-105, iv, 48 p., https://doi.org/10.3133/ofr97105.","productDescription":"iv, 48 p.","numberOfPages":"53","costCenters":[],"links":[{"id":170106,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97105.GIF"},{"id":279822,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0105/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Morristown","otherGeospatial":"Ryder Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.75,43.5 ], [ -72.75,43.625 ], [ -72.625,43.625 ], [ -72.625,43.5 ], [ -72.75,43.5 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a5bb9","contributors":{"authors":[{"text":"Boehmler, Erick M.","contributorId":96303,"corporation":false,"usgs":true,"family":"Boehmler","given":"Erick","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":240411,"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":240410,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49915,"text":"ofr97343 - 1997 - Level II scour analysis for Bridge 53 (WILMVT01000053) on State Route 100, crossing Cold Brook, Wilmington, Vermont","interactions":[],"lastModifiedDate":"2014-01-05T13:06:31","indexId":"ofr97343","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-343","title":"Level II scour analysis for Bridge 53 (WILMVT01000053) on State Route 100, crossing Cold Brook, Wilmington, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nWILMVT01000053 on State Route 100 crossing Cold Brook, Wilmington, 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 \nsouth-central Vermont. The 8.38-mi2 drainage area is in a predominantly rural and forested \nbasin. In the vicinity of the study site, the surface cover predominantly is pasture except for \nthe immediate channel banks, which are tree covered.
\nIn the study area, Cold Brook has a straight channel with a slope of approximately 0.04 ft/ft, \nan average channel top width of 63 feet and an average bank height of 9 feet. The channel is \nconstructed with stone fill completely covering both banks for 300 feet upstream of the site. \nThe predominant channel bed materials are gravel and cobbles with a median grain size \n(D50) of 66.2 mm (0.217 ft). The geomorphic assessment at the time of the Level I and \nLevel II site visit on August 7, 1996, indicated that the reach was constructed.
\nThe State Route 100 crossing of Cold Brook is a 23-ft-long, two-lane bridge divided by a \nmedian strip consisting of one 20-foot concrete span (Vermont Agency of Transportation, \nwritten communication, November 1, 1995). The bridge is supported by vertical, concrete \nabutments with wingwalls. The channel is not skewed to the opening and the opening-skew-\nto-roadway also is zero degrees.
\nThe scour protection measure at the site was type-2 stone fill (less than 36 inches diameter) \non the upstream banks, the upstream wingwalls, and the downstream left wingwall. \nAdditional details describing conditions at the site are included in the Level II Summary \nand Appendices D and E.
\nScour depths and rock rip-rap sizes were computed using the general guidelines described \nin Hydraulic Engineering Circular 18 (Richardson and others, 1995). Total scour at a \nhighway crossing is comprised of three components: 1) long-term streambed degradation; \n2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) \nand; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is \nthe sum of the three components. Equations are available to compute depths for contraction \nand local scour and a summary of the results of these computations follows.
\nContraction scour for all modelled flows ranged from 0.6 to 2.7 ft. The worst-case \ncontraction scour occurred at the 500-year discharge. Abutment scour ranged from 4.8 to \n10.9 ft. The worst-case abutment scour occurred at the left abutment for 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/ofr97343","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Boehmler, E.M., 1997, Level II scour analysis for Bridge 53 (WILMVT01000053) on State Route 100, crossing Cold Brook, Wilmington, Vermont: U.S. Geological Survey Open-File Report 97-343, iv, 49 p., https://doi.org/10.3133/ofr97343.","productDescription":"iv, 49 p.","numberOfPages":"54","costCenters":[],"links":[{"id":170176,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/usgs_thumb.jpg"},{"id":279770,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0343/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Wilmington","otherGeospatial":"Cold Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.75,43.5 ], [ -72.75,43.625 ], [ -72.625,43.625 ], [ -72.625,43.5 ], [ -72.75,43.5 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a5b46","contributors":{"authors":[{"text":"Boehmler, Erick M.","contributorId":96303,"corporation":false,"usgs":true,"family":"Boehmler","given":"Erick","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":240470,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":49917,"text":"ofr97345 - 1997 - Level II scour analysis for Bridge 11R (ROCKTH0001011R) on Town Highway 1 (VT 121 & FAS 125), crossing the Saxtons River, Rockingham, Vermont","interactions":[],"lastModifiedDate":"2014-01-05T12:42:26","indexId":"ofr97345","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-345","title":"Level II scour analysis for Bridge 11R (ROCKTH0001011R) on Town Highway 1 (VT 121 & FAS 125), crossing the Saxtons River, Rockingham, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nROCKTH0001011R on Town Highway 1 crossing the Saxtons River, Rockingham, \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 southeastern Vermont. The 68.3-mi2\n drainage area is in a predominantly rural and \nforested basin. In the vicinity of the study site, the surface cover consists of houses, short \ngrass, and scattered trees except along the immediate river banks, which are tree covered.
\nIn the study area, the Saxtons River has a sinuous channel with a slope of approximately \n0.005 ft/ft, an average channel top width of 121 ft and an average bank height of 8 ft. The \npredominant channel bed materials are gravel and cobbles with a median grain size (D50) of \n109 mm (0.359 ft). The geomorphic assessment at the time of the Level I and Level II site \nvisit on September 3, 1996, indicated that the reach was laterally unstable. Lateral \ninstability was evident with respect to a cut-bank on the left bank upstream with slip failure \nof bank material. Furthermore, there is a wide point bar along the right bank upstream \nopposite the cut-bank.
\nThe Town Highway 1 crossing of the Saxtons River is a 184-ft-long, two-lane bridge \nconsisting of three steel-beam spans (Vermont Agency of Transportation, written communication, March 30, 1995). \nThe bridge is supported by vertical, concrete, skeletal-style abutment walls with spill-through embankments adjacent to \neach wall. The channel is skewed approximately 35 degrees to the opening while the opening-skew-to-roadway is 30 \ndegrees.
\nThe only scour protection measure at the site was type-3 stone fill (less than 48 inches \ndiameter) on the spill-through embankments. Additional details describing conditions at the \nsite are included in the Level II Summary and Appendices D \nand E.
\nScour depths and rock rip-rap sizes were computed using the general guidelines described \nin Hydraulic Engineering Circular 18 (Richardson and others, 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 all modelled flows at this site. Abutment \nscour ranged from 9.0 to 13.4 feet. The worst-case abutment scour occurred at the 500-year \ndischarge for the left abutment. There are two piers for which computed pier scour ranged \nfrom 9.0 to 18.4 feet. The left and right piers in this report are presented as pier 1 and pier 2, \nrespectively. The worst-case pier scour occurred at pier 2 for 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/ofr97345","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Boehmler, E.M., 1997, Level II scour analysis for Bridge 11R (ROCKTH0001011R) on Town Highway 1 (VT 121 & FAS 125), crossing the Saxtons River, Rockingham, Vermont: U.S. Geological Survey Open-File Report 97-345, iv, 49 p., https://doi.org/10.3133/ofr97345.","productDescription":"iv, 49 p.","numberOfPages":"54","costCenters":[],"links":[{"id":170100,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97345.GIF"},{"id":279768,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0345/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Rockingham","otherGeospatial":"Saxtons River","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.75,43.5 ], [ -72.75,43.625 ], [ -72.625,43.625 ], [ -72.625,43.5 ], [ -72.75,43.5 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b1ae4b07f02db6a83de","contributors":{"authors":[{"text":"Boehmler, Erick M.","contributorId":96303,"corporation":false,"usgs":true,"family":"Boehmler","given":"Erick","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":240472,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":49918,"text":"ofr97346 - 1997 - Level II scour analysis for Bridge 43 (BENNCYDEPO0043) on Depot Street, crossing the Walloomsac River, Bennington, Vermont","interactions":[],"lastModifiedDate":"2014-01-05T12:21:42","indexId":"ofr97346","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-346","title":"Level II scour analysis for Bridge 43 (BENNCYDEPO0043) on Depot Street, crossing the Walloomsac River, Bennington, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nBENNCYDEPO0043 on the Depot Street crossing of the Walloomsac River, Bennington, \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 Green Mountain section of the New England physiographic province in \nsouthwestern Vermont. The 30.1-mi2\n drainage area is a predominantly rural and forested \nbasin. The bridge site is located within an urban setting in the Town of Bennington with \nbuildings and parking lots on overbanks.
\nIn the study area, the Walloomsac River has a straight channel with constructed channel \nbanks through much of the reach. The channel is located on a delta and has a slope of \napproximately 0.02 ft/ft, an average channel top width of 48 ft and an average bank height \nof 6 ft. The predominant channel bed material is cobble with a median grain size (D50) of \n108 mm (0.356 ft). The geomorphic assessment at the time of the Level I and Level II site \nvisit on August 5, 1996, indicated that the reach was stable.
\nThe Depot Street crossing of the Walloomsac River is a 46-ft-long, two-lane bridge \nconsisting of one 40-foot concrete span (Vermont Agency of Transportation, written \ncommunication, December 13, 1995). The bridge is supported by vertical, concrete \nabutments with wingwalls. The channel is skewed approximately \n5 degrees to the opening and the opening-skew-to-roadway is 15 degrees.
\nScour countermeasures at the site include type-2 stone fill (less than 36 inches diameter) at \nthe upstream end of the upstream right wing wall and type-1 stone fill (less than 12 inches \ndiameter) along the base of the upstream left wing wall. Downstream banks are protected by \nconcrete and stone walls. The upstream right bank is protected by alternating type-2 stone \nfill and masonry walls. Additional details describing conditions at the site are included in \nthe Level II Summary and Appendices D and E.
\nScour depths and recommended rock rip-rap sizes were computed using the general \nguidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995). \nTotal scour at a highway crossing is comprised of three components: 1) long-term \nstreambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction \nin flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and \nabutments). Total scour is the sum of the three components. Equations are available to \ncompute depths for contraction and local scour and a summary of the results of these \ncomputations follows.
\nContraction scour computed for all modelled flows ranged from 0.0 to 4.1 ft. \nThe worst-case contraction scour occurred at the 500-year discharge. \nComputed right abutment scour ranged from 2.9 to 13.4 ft. with the worst-case \nscour occurring at the 500-year discharge. Computed left abutment scour \nranged from 5.6 to 16.3 ft. with the worst-case scour also occurring at the 500-year discharge. \nAdditional information on scour depths and depths to armoring are included in the section titled \n“Scour Results”. Scoured-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 depths were calculated \nassuming an infinite depth of erosive material and a homogeneous particle-size distribution.
\nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr97346","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Olson, S.A., 1997, Level II scour analysis for Bridge 43 (BENNCYDEPO0043) on Depot Street, crossing the Walloomsac River, Bennington, Vermont: U.S. Geological Survey Open-File Report 97-346, iv, 50 p., https://doi.org/10.3133/ofr97346.","productDescription":"iv, 50 p.","numberOfPages":"55","costCenters":[],"links":[{"id":170101,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/usgs_thumb.jpg"},{"id":279767,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0346/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Bennington","otherGeospatial":"Walloomsac River","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -73.25,42.75 ], [ -73.25,43.0 ], [ -73.125,43.0 ], [ -73.125,42.75 ], [ -73.25,42.75 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a615b","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":240473,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":49919,"text":"ofr97362 - 1997 - Level II scour analysis for Bridge 7 (CHESTH00030007) on Town Highway 3, crossing the South Branch Williams River, Chester, Vermont","interactions":[],"lastModifiedDate":"2014-01-04T15:31:30","indexId":"ofr97362","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-362","title":"Level II scour analysis for Bridge 7 (CHESTH00030007) on Town Highway 3, crossing the South Branch Williams River, Chester, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nCHESTH00030007 on Town Highway 3 which is also State Route 35 crossing the South \nBranch Williams River, Chester, Vermont (figures 1–8). A Level II study is a basic \nengineering analysis of the site, including a quantitative analysis of stream stability and \nscour (U.S. Department of Transportation, 1993). Results of a Level I scour investigation \nalso are included in Appendix E of this report. A Level I investigation provides a qualitative \ngeomorphic characterization of the study site. Information on the bridge, gleaned from \nVermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level \nI and Level II analyses and is found in Appendix D.
\nThe site is in the New England Upland section of the New England physiographic province \nin southern Vermont. The 10.4-mi2 drainage area is in a predominantly rural and forested \nbasin. In the vicinity of the study site, the surface cover is pasture on the upstream right \nbank while the immediate bank has some trees. Downstream of the bridge and the upstream \nleft bank are forested.
\nIn the study area, the South Branch Williams River has an incised, sinuous channel with a \nslope of approximately 0.03 ft/ft, an average channel top width of 65 ft and an average bank \nheight of 4 ft. The channel bed material ranges from gravel to boulder with a median grain \nsize (D50) of 70.5 mm (0.231 ft). The geomorphic assessment at the time of the Level I and \nLevel II site visit on August 26, 1996, indicated that the reach was laterally unstable. There \nare cutbanks on both the left and right banks alternating with point bars in the upstream \nreach.
\nThe Town Highway 3 (VT 35) crossing of the South Branch Williams River is a 74-ft-long, \ntwo-lane bridge consisting of one 72-foot steel-beam span (Vermont Agency of \nTransportation, written communication, March 30, 1995). The bridge is supported by spill-\nthrough abutments. The channel is skewed approximately 5 degrees to the opening and the \nopening-skew-to-roadway is also 5 degrees.
\nThree channel scour holes 1.0 ft deeper than the mean thalweg depth were observed during \nthe Level I assessment in the upstream reach. There are no scour protection measures at the \nsite. Additional details describing conditions at the site are included in the Level II \nSummary and Appendices D and E.
\nScour depths and recommended rock rip-rap sizes were computed using the general \nguidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995). \nTotal scour at a highway crossing is comprised of three components: 1) long-term \nstreambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction \nin flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and \nabutments). Total scour is the sum of the three components. Equations are available to \ncompute depths for contraction and local scour and a summary of the results of these \ncomputations follows.
\nContraction scour for all modelled flows ranged from 0.0 to 0.4 ft. The worst-case \ncontraction scour occurred at the 100-year. Abutment scour ranged from 4.1 to 15.5 ft. The \nworst-case abutment scour occurred at the 500-year. Additional information on scour \ndepths and depths to armoring are included in the section titled “Scour Results”. Scoured-\nstreambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. \nA cross-section of the scour computed at the bridge is presented in figure 8. Scour depths \nwere calculated assuming an infinite depth of erosive material and a homogeneous particle-\nsize distribution.
\nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr97362","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Burns, R.L., 1997, Level II scour analysis for Bridge 7 (CHESTH00030007) on Town Highway 3, crossing the South Branch Williams River, Chester, Vermont: U.S. Geological Survey Open-File Report 97-362, iv, 50 p., https://doi.org/10.3133/ofr97362.","productDescription":"iv, 50 p.","numberOfPages":"55","costCenters":[],"links":[{"id":170102,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97362.GIF"},{"id":279766,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0362/report.pdf"}],"scale":"62500","country":"United States","state":"Vermont","city":"Chester","otherGeospatial":"South Branch Williams River","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.75,43.0 ], [ -72.75,43.5 ], [ -72.5,43.5 ], [ -72.5,43.0 ], [ -72.75,43.0 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b16e4b07f02db6a576d","contributors":{"authors":[{"text":"Burns, Ronda L.","contributorId":71602,"corporation":false,"usgs":true,"family":"Burns","given":"Ronda","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":240474,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":49999,"text":"ofr97760 - 1997 - Level II scour analysis for Bridge 4 (MAIDTH00070004) on Town Highway 7, crossing Cutler Mill Brook, Maidstone, Vermont","interactions":[],"lastModifiedDate":"2013-12-17T12:28:59","indexId":"ofr97760","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-760","title":"Level II scour analysis for Bridge 4 (MAIDTH00070004) on Town Highway 7, crossing Cutler Mill Brook, Maidstone, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nMAIDTH00070004 on Town Highway 7 crossing the Cutler Mill Brook, Maidstone, \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 White Mountain section of the New England physiographic province in \nnortheastern Vermont. The 18.1-mi2\n drainage area is in a predominantly rural and forested \nbasin. In the vicinity of the study site, the surface cover is predominantly shrub and \nbrushland.
\nIn the study area, the Cutler Mill Brook has a non-incised, meandering channel with local \nbraiding and a slope of approximately 0.004 ft/ft, an average channel top width of 43 ft and \nan average bank height of 2 ft. The channel bed material ranges from sand to cobble with a \nmedian grain size (D50) of 27.6 mm (0.091 ft). The geomorphic assessment at the time of \nthe Level I and Level II site visit on July 19, 1995, indicated that the reach was laterally \nunstable due to large meanders in the channel.
\nThe Town Highway 7 crossing of the Cutler Mill Brook is a 25-ft-long, one-lane bridge \nconsisting of one 22-foot concrete span (Vermont Agency of Transportation, written \ncommunication, August 5, 1994). The opening length of the structure parallel to the bridge \nface is 21.7 ft. The bridge is supported by vertical, concrete abutments with wingwalls. The \nchannel is skewed approximately 20 degrees to the opening while the opening-skew-to-roadway is 0 degrees.
\nA scour hole 2.0 ft deeper than the mean thalweg depth was observed along the left \nabutment during the Level I assessment. The only scour protection measure at the site was \ntype-2 stone fill (less than 36 inches diameter) along both banks upstream, along the entire \nbase length of the upstream left wingwall, and along the upstream end of the upstream right \nwingwall. Additional details describing conditions at the site are included in the Level II \nSummary and Appendices D and E.
\nScour depths and recommended rock rip-rap sizes were computed using the general \nguidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995) \nfor the 100- and 500-year discharges. In addition, the incipient roadway-overtopping \ndischarge was determined and analyzed as another potential worst-case scour scenario. \nTotal scour at a highway crossing is comprised of three components: 1) long-term \nstreambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction \nin flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and \nabutments). Total scour is the sum of the three components. Equations are available to \ncompute depths for contraction and local scour and a summary of the results of these \ncomputations follows.
\nContraction scour for all modelled flows ranged from 2.2 to 4.2 ft. The worst-case \ncontraction scour occurred at the 500-year discharge. Abutment scour ranged from 5.7 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.
\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/ofr97760","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Striker, L.K., and Medalie, L., 1997, Level II scour analysis for Bridge 4 (MAIDTH00070004) on Town Highway 7, crossing Cutler Mill Brook, Maidstone, Vermont: U.S. Geological Survey Open-File Report 97-760, iv, 51 p., https://doi.org/10.3133/ofr97760.","productDescription":"iv, 51 p.","numberOfPages":"56","costCenters":[],"links":[{"id":176340,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97760.GIF"},{"id":279679,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0760/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Maidstone","otherGeospatial":"Cutler Mill Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -71.625,44.5 ], [ -71.625,44.625 ], [ -71.5,44.625 ], [ -71.5,44.5 ], [ -71.625,44.5 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a61ed","contributors":{"authors":[{"text":"Striker, Lora K.","contributorId":41481,"corporation":false,"usgs":true,"family":"Striker","given":"Lora","email":"","middleInitial":"K.","affiliations":[],"preferred":false,"id":240611,"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":240610,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49904,"text":"ofr97215 - 1997 - Level II scour analysis for Bridge 8 (STAMVT01000008) on State Highway 100, crossing the North Branch of the Hoosic River, Stamford, Vermont","interactions":[],"lastModifiedDate":"2013-12-20T10:17:32","indexId":"ofr97215","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-215","title":"Level II scour analysis for Bridge 8 (STAMVT01000008) on State Highway 100, crossing the North Branch of the Hoosic River, Stamford, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure STAMVT01000008 on Vermont Highway 100 crossing the North Branch of the Hoosic River, Stamford, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including a quantitative analysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of a Level I scour investigation also are included in Appendix E of this report. A Level I investigation provides a qualitative geomorphic characterization of the study site. Information on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is found in Appendix D.\nThe site is in the Green Mountain section of the New England physiographic province in southern Vermont. The 6.8-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the upstream right bank surface cover is short grass and the upstream left bank is a sand/gravel lot while the immediate banks are covered by shrubs and trees. Downstream of the bridge banks are forested.\nIn the study area, the North Branch of the Hoosic River has an incised, sinuous channel with a slope of approximately 0.02 ft/ft, an average channel top width of 37 ft and an average bank height of 3 ft. The channel bed material is predominantly cobble with a median grain size (D50) of 88.0 mm (0.289 ft). The geomorphic assessment at the time of the Level I and Level II site visit on August 1, 1996, indicated that the reach was laterally unstable.\nThe Vermont Highway 100 crossing of the North Branch of the Hoosic River is a 39-ft-long, two-lane bridge consisting of one 37-foot steel-beam span (Vermont Agency of Transportation, written communication, November 1, 1995). The bridge is supported by vertical, concrete abutments. The channel is skewed approximately 20 degrees to the opening while the opening-skew-to-roadway is 15 degrees.\nA scour hole 2.5 ft deeper than the mean thalweg depth was observed along the upstream end of the right abutment during the Level I assessment. The only scour protection measure at the site was type-3 stone fill (less than 48 inches diameter) at the downstream ends of the left and right abutments extending downstream along the left bank for 13 feet and along the right bank for 16 feet. The plans show stone fill placed at the upstream ends of the abutments. The protection at the upstream end of the right abutment has failed due to stream migration towards the right bank. The protection at the upstream end of the left abutment was not detected due to the sand/gravel pile, for District 1 maintenance, migrating into the channel (Figure 3). Additional details describing conditions at the site are included in the Level II Summary and Appendices D and E.\nScour depths and rock rip-rap sizes were computed using the general guidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995). Total scour at a highway crossing is comprised of three components: 1) long-term streambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is the sum of the three components. Equations are available to compute depths for contraction and local scour and a summary of the results of these computations follows.\nContraction scour for all modelled flows ranged from 0.6 to 3.0 ft. The worst-case contraction scour occurred at the 500-year discharge. Left abutment scour ranged from 14.4 to 17.8 ft. Right abutment scour ranged from 8.1 to 11.1 ft. The worst-case abutment scour occurred at the 500-year discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution.\nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, computed scour depths are evaluated in combination with other information including (but not limited to) historical performance during flood events, the geomorphic stability assessment, existing scour protection measures, and the results of the hydraulic analyses. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein.","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr97215","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Ivanoff, M.A., 1997, Level II scour analysis for Bridge 8 (STAMVT01000008) on State Highway 100, crossing the North Branch of the Hoosic River, Stamford, Vermont: U.S. Geological Survey Open-File Report 97-215, iv, 50 p., https://doi.org/10.3133/ofr97215.","productDescription":"iv, 50 p.","numberOfPages":"55","costCenters":[],"links":[{"id":169642,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97215.PNG"},{"id":279781,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0215/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Stamford","otherGeospatial":"Hoosic River","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -73.125,42.75 ], [ -73.125,42.875 ], [ -73.0,42.875 ], [ -73.0,42.75 ], [ -73.125,42.75 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b16e4b07f02db6a562f","contributors":{"authors":[{"text":"Ivanoff, Michael A.","contributorId":27105,"corporation":false,"usgs":true,"family":"Ivanoff","given":"Michael","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":240454,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":50000,"text":"ofr97765 - 1997 - Level II scour analysis for Bridge 4 (RYEGTH00050004) on Town Highway 5, crossing the Wells River, Ryegate, Vermont","interactions":[],"lastModifiedDate":"2013-12-17T16:18:31","indexId":"ofr97765","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-765","title":"Level II scour analysis for Bridge 4 (RYEGTH00050004) on Town Highway 5, crossing the Wells River, Ryegate, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nRYEGTH00050004 on Town Highway 5 crossing the Wells River, Ryegate, 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 eastern Vermont. The 84.7-mi2\n drainage area is in a predominantly rural and forested \nbasin. In the vicinity of the study site, the surface cover includes shrubs and brush on the \nupstream left bank and downstream right bank of the bridge. The upstream right bank and \ndownstream left bank of the bridge is forested.\nIn the study area, the Wells River has an incised, sinuous channel with a slope of \napproximately 0.008 ft/ft, an average channel top width of 107 ft and an average bank \nheight of 11 ft. The channel bed material ranges from gravel to boulder with a median grain \nsize (D50) of 67.4 mm (0.221 ft). The geomorphic assessment at the time of the Level I and \nLevel II site visit on August 21, 1995, indicated that the reach was laterally unstable with \nmass wasting along the upstream right bank.\nThe Town Highway 5 crossing of the Wells River is a 108-ft-long, two-lane bridge \nconsisting of a 100-foot steel-beam span (Vermont Agency of Transportation, written \ncommunication, March 27, 1995). The opening length of the structure parallel to the bridge \nface is 93.4 ft. The bridge is supported by vertical, stone block abutments with wingwalls. \nThe channel is skewed approximately 50 degrees to the opening while the opening-skew-toroadway is 45 degrees. \nThe scour protection counter-measures at the site included type-1 stone fill (less than 12 \ninches diameter) along the downstream left road embankment. Also, type-2 stone fill (less \nthan 36 inches diameter) along the upstream right wingwall, extending 30 feet upstream \nalong the right bank, along the downstream end of the downstream right wingwall, along \nthe downstream right road embankment, and along the downstream left bank below the old \nrailroad bed. Additional details describing conditions at the site are included in the Level II \nSummary and Appendices D and E.\nScour depths and recommended rock rip-rap sizes were computed using the general \nguidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995) \nfor the 100- and 500-year discharges. Total scour at a highway crossing is comprised of \nthree components: 1) long-term streambed degradation; 2) contraction scour (due to \naccelerated flow caused by a reduction in flow area at a bridge) and; 3) local scour (caused \nby accelerated flow around piers and abutments). Total scour is the sum of the three \ncomponents. Equations are available to compute depths for contraction and local scour and \na summary of the results of these computations follows.\nContraction scour for all modelled flows ranged from 1.8 to 2.6 ft. The worst-case \ncontraction scour occurred at the 500-year discharge. Abutment scour ranged from 10.2 to \n22.6 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","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr97765","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Ivanoff, M.A., and Hammond, R.E., 1997, Level II scour analysis for Bridge 4 (RYEGTH00050004) on Town Highway 5, crossing the Wells River, Ryegate, Vermont: U.S. Geological Survey Open-File Report 97-765, iv, 48 p., https://doi.org/10.3133/ofr97765.","productDescription":"iv, 48 p.","numberOfPages":"53","costCenters":[],"links":[{"id":176341,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97765.PNG"},{"id":279678,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0765/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Ryegate","otherGeospatial":"Wells River","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.25,44.125 ], [ -72.25,44.25 ], [ -72.125,44.25 ], [ -72.125,44.125 ], [ -72.25,44.125 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a6209","contributors":{"authors":[{"text":"Ivanoff, Michael A.","contributorId":27105,"corporation":false,"usgs":true,"family":"Ivanoff","given":"Michael","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":240612,"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":240613,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49901,"text":"ofr97212 - 1997 - Level II scour analysis for Bridge 19 (CHARTH00390019) on Town Highway 39, crossing Mad Brook, Charleston, Vermont","interactions":[],"lastModifiedDate":"2013-12-20T11:29:33","indexId":"ofr97212","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-212","title":"Level II scour analysis for Bridge 19 (CHARTH00390019) on Town Highway 39, crossing Mad Brook, Charleston, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure CHARTH00390019 on Town Highway 39 crossing Mad Brook, Charleston, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including a quantitative analysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of a Level I investigation also are included in this report in Appendix E. A Level I study provides a qualitative geomorphic characterization of the study site. Information on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is found in Appendix D.\nThe site is in the White Mountain section of the New England physiographic province in northeastern Vermont in the town of Charleston. The 6.54-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is forest except for the upstream left side which is covered primarily with shrubs and brush. The immediate banks have dense woody vegetation.\nIn the study area, Mad Brook has an incised, sinuous channel with a slope of approximately 0.023 ft/ft, an average channel top width of 40 ft and an average channel depth of 4 ft. The predominant channel bed material is cobble with a median grain size (D50) of 135.0 mm (0.443 ft). The geomorphic assessment on October 26, 1994 indicated that the reach was laterally unstable due to long-term lateral migration of the channel. Data collection for the level II analysis was accomplished on October 26, 1994 and July 24, 1995.\nThe Town Highway 39 crossing of Mad Brook is a 34-ft-long, two-lane bridge consisting of one 31-foot steel-beam span (Vermont Agency of Transportation, written communication, August 4, 1994). The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 40 degrees to the opening while the opening-skew-to-roadway is 45 degrees.\nA scour hole 1.5 ft deeper than the mean thalweg depth was observed along the right abutment during the Level I assessment. The scour protection measures evident at the site were type-2 stone fill (less than 36 inches diameter) on the upstream left wingwall and upstream end of the left abutment wall. Type-3 stone fill (less than 48 inches diameter) was\nnoted on the upstream right wingwall and the upstream side of the left road approach embankment. Additional details describing conditions at the site are included in the Level II Summary and Appendices D and E.\nScour depths and rock rip-rap sizes were computed using the general guidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995). Total scour at a highway crossing is comprised of three components: 1) long-term streambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is the sum of the three components. Equations are available to compute depths for contraction and local scour and a summary of the results of these computations follows.\nContraction scour for all modelled flows was 0.0 ft. Abutment scour ranged from 9.5 to 16.7 ft. The worst-case abutment scour occurred at the 500-year discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution.\nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, computed scour depths are evaluated in combination with other information including (but not limited to) historical performance during flood events, the geomorphic stability assessment, existing scour protection measures, and the results of the hydraulic analyses. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein.","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr97212","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Boehmler, E.M., and Hammond, R.E., 1997, Level II scour analysis for Bridge 19 (CHARTH00390019) on Town Highway 39, crossing Mad Brook, Charleston, Vermont: U.S. Geological Survey Open-File Report 97-212, iv, 47 p., https://doi.org/10.3133/ofr97212.","productDescription":"iv, 47 p.","numberOfPages":"52","costCenters":[],"links":[{"id":170452,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97212.PNG"},{"id":279802,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0212/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Charleston","otherGeospatial":"Mad Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.75,43.5 ], [ -72.75,43.625 ], [ -72.625,43.625 ], [ -72.625,43.5 ], [ -72.75,43.5 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b1ae4b07f02db6a81cf","contributors":{"authors":[{"text":"Boehmler, Erick M.","contributorId":96303,"corporation":false,"usgs":true,"family":"Boehmler","given":"Erick","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":240449,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Hammond, Robert E.","contributorId":61862,"corporation":false,"usgs":true,"family":"Hammond","given":"Robert","email":"","middleInitial":"E.","affiliations":[],"preferred":false,"id":240448,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49902,"text":"ofr97213 - 1997 - Level II scour analysis for Bridge 7 (CHARTH00010007) on Town Highway 1, crossing Mad Brook, Charleston, Vermont","interactions":[],"lastModifiedDate":"2013-12-20T11:20:57","indexId":"ofr97213","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-213","title":"Level II scour analysis for Bridge 7 (CHARTH00010007) on Town Highway 1, crossing Mad Brook, Charleston, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nCHARTH00010007 on town highway 1 crossing Mad Brook, Charleston, Vermont (figures \n1–8). A Level II study is a basic engineering analysis of the site, including a quantitative \nanalysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of \na Level I scour investigation also are included in Appendix E of this report. A Level I \ninvestigation provides a qualitative geomorphic characterization of the study site. \nInformation on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) \nfiles, was compiled prior to conducting Level I and Level II analyses and is found in \nAppendix D.\nThe site is in the White Mountain section of the New England physiographic province in \nnorth-central Vermont in the town of Charleston. The 6.59-mi2\n drainage area is in a \npredominantly rural and forested basin. In the vicinity of the study site, the surface cover is \npasture except for the upstream left bank, which is forest. The stream banks are tree covered \nupstream and on the downstream left bank side.\nIn the study area, Mad Brook has an incised, sinuous channel with a slope of approximately \n0.01 ft/ft, an average channel top width of 41 ft and an average channel depth of 5 ft. The \npredominant channel bed materials range from gravel to boulders with a median grain size \n(D50) of 105 mm (0.344 ft). The geomorphic assessment at the time of the Level I and Level \nII site visit on October 28, 1994, indicated that the reach was stable.\nThe town highway 1 crossing of Mad Brook is a 27-ft-long, two-lane bridge consisting of \none 25-foot concrete T-beam span (Vermont Agency of Transportation, written \ncommunication, August 4, 1994). The bridge is supported by vertical, concrete abutments \nwith wingwalls. The channel is skewed approximately 10 degrees to the opening. The \nopening-skew-to-roadway computed from surveyed data is 5 degrees, but historical bridge \nrecords indicate this angle is closer to 10 degrees.\nThere was scour evident during the Level I assessment due to the presence of two \nsubfootings at the base of each abutment wall. Although the subfootings may have been \nconstructed at the same time as the abutment walls, the subfootings may have been \nconstructed at a later time in response to streambed degradation under the bridge. The right \nabutment was noted as undermined during the Level I assessment. Scour protection \nmeasures at the site were type-1 stone fill (less than 12 inches diameter) on the upstream \nright and downstream road embankments and type-2 stone fill on each wingwall and the \ndownstream left bank. Additional details describing conditions at the site are included in the \nLevel II Summary and Appendices D and E.\nScour depths and rock rip-rap sizes were computed using the general guidelines described \nin Hydraulic Engineering Circular 18 (Richardson and others, 1995). Total scour at a \nhighway crossing is comprised of three components: 1) long-term streambed degradation; \n2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) \nand; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is \nthe sum of the three components. Equations are available to compute depths for contraction \nand local scour and a summary of the results of these computations follows.\nContraction scour for all modelled flows ranged from 0.0 to 0.3 ft. The worst-case \ncontraction scour occurred at the incipient overtopping discharge, which was less than the \n100-year discharge. Abutment scour ranged from 6.2 to 9.4 ft. The worst-case abutment \nscour for the right abutment was 9.4 feet at the 100-year discharge. The worst-case \nabutment scour for the left abutment was 8.6 feet at the incipient overtopping discharge. \nAdditional information on scour depths and depths to armoring are included in the section \ntitled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, \nare presented in tables 1 and 2. A cross-section of the scour computed at the bridge is \npresented in figure 8. Scour depths were calculated assuming an infinite depth of erosive \nmaterial and a homogeneous particle-size distribution. \n It is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr97213","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Boehmler, E.M., and Weber, M.A., 1997, Level II scour analysis for Bridge 7 (CHARTH00010007) on Town Highway 1, crossing Mad Brook, Charleston, Vermont: U.S. Geological Survey Open-File Report 97-213, iv, 50 p., https://doi.org/10.3133/ofr97213.","productDescription":"iv, 50 p.","numberOfPages":"55","costCenters":[],"links":[{"id":170453,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97213.PNG"},{"id":279801,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0213/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Charleston","otherGeospatial":"Mad Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.75,43.5 ], [ -72.75,43.625 ], [ -72.625,43.625 ], [ -72.625,43.5 ], [ -72.75,43.5 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b16e4b07f02db6a5749","contributors":{"authors":[{"text":"Boehmler, Erick M.","contributorId":96303,"corporation":false,"usgs":true,"family":"Boehmler","given":"Erick","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":240451,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Weber, Matthew A.","contributorId":41483,"corporation":false,"usgs":true,"family":"Weber","given":"Matthew","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":240450,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":50001,"text":"ofr97766 - 1997 - Level II scour analysis for Bridge 46 (BRNETH00610046) on Town Highway 61, crossing East Peacham Brook, Barnet, Vermont","interactions":[],"lastModifiedDate":"2013-12-17T16:11:32","indexId":"ofr97766","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-766","title":"Level II scour analysis for Bridge 46 (BRNETH00610046) on Town Highway 61, crossing East Peacham Brook, Barnet, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nBRNETH00610046 on Town Highway 61 crossing East Peacham Brook, Barnet, 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 15.8-mi2\n drainage area is in a predominantly rural and forested \nbasin. In the vicinity of the study site, the surface cover is forest.\nIn the study area, East Peacham Brook has an incised, sinuous channel with a slope of \napproximately 0.02 ft/ft, an average channel top width of 59 ft and an average bank height \nof 5 ft. The channel bed material ranges from gravel to boulder with a median grain size \n(D50) of 121 mm (0.397 ft). The geomorphic assessment at the time of the Level I and Level \nII site visit on August 23, 1995, indicated that the reach was laterally unstable with cut \nbanks both upstream and downstream of the bridge.\nThe Town Highway 61 crossing of East Peacham Brook is a 28-ft-long, one-lane bridge \nconsisting of one 26-foot steel-beam span (Vermont Agency of Transportation, written \ncommunication, March 24, 1995). The opening length of the structure parallel to the bridge \nface is 24.5 ft. The bridge is supported by vertical, concrete abutments with wingwalls. The \nchannel is skewed approximately 5 degrees to the opening while the opening-skew-toroadway is zero degrees. \nA scour hole 0.7 ft deeper than the mean thalweg depth was observed along the upstream \nleft wingwall extending along the left abutment during the Level I assessment. The only \nscour protection measure at the site was type-2 stone fill (less than 36 inches diameter) at \nthe upstream end of the upstream left wingwall extending along the upstream left bank and \nalong the entire base of the downstream left wingwall. Additional details describing \nconditions at the site are included in the Level II Summary and Appendices D and E.\nScour depths and recommended rock rip-rap sizes were computed using the general \nguidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995) \nfor the 100- and 500-year discharges. In addition, the incipient roadway-overtopping \ndischarge is determined and analyzed as another potential worst-case scour scenario. Total \nscour at a highway crossing is comprised of three components: 1) long-term streambed \ndegradation; 2) contraction scour (due to accelerated flow caused by a reduction in flow \narea at a bridge) and; 3) local scour (caused by accelerated flow around piers and \nabutments). Total scour is the sum of the three components. Equations are available to \ncompute depths for contraction and local scour and a summary of the results of these \ncomputations follows.\nContraction scour for all modelled flows ranged from 0 to 1.2 ft. The worst-case contraction \nscour occurred at the 500-year discharge. Abutment scour ranged from 10.4 to 13.9 ft. The \nworst-case abutment scour occurred at the 500-year discharge. 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/ofr97766","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Ivanoff, M.A., 1997, Level II scour analysis for Bridge 46 (BRNETH00610046) on Town Highway 61, crossing East Peacham Brook, Barnet, Vermont: U.S. Geological Survey Open-File Report 97-766, iv, 51 p., https://doi.org/10.3133/ofr97766.","productDescription":"iv, 51 p.","numberOfPages":"56","costCenters":[],"links":[{"id":176342,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97766.PNG"},{"id":279677,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0766/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Barnet","otherGeospatial":"East Peacham Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.25,44.25 ], [ -72.25,44.375 ], [ -72.0,44.375 ], [ -72.0,44.25 ], [ -72.25,44.25 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a60f8","contributors":{"authors":[{"text":"Ivanoff, Michael A.","contributorId":27105,"corporation":false,"usgs":true,"family":"Ivanoff","given":"Michael","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":240614,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":50003,"text":"ofr97768 - 1997 - Level II scour analysis for Bridge 22 (WALDTH00180022) on Town Highway 18, crossing Coles Brook, Walden, Vermont","interactions":[],"lastModifiedDate":"2013-12-17T16:01:28","indexId":"ofr97768","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-768","title":"Level II scour analysis for Bridge 22 (WALDTH00180022) on Town Highway 18, crossing Coles Brook, Walden, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nWALDTH00180022 on Town Highway 18 crossing Coles Brook also known as Joes \nBrook, Walden, 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 northeastern Vermont. The 12.5-mi2\n drainage area is in a predominantly rural and \nforested basin. In the vicinity of the study site, the surface cover is predominantly forested \nwhile the downstream left bank is shrub and brushland.\nIn the study area, the Coles Brook has an incised, sinuous channel with a slope of \napproximately 0.004 ft/ft, an average channel top width of 54 ft and an average bank height \nof 4 ft. The channel bed material ranges from gravel to bedrock with a median grain size \n(D50) of 124.1 mm (0.407 ft). The D50 was taken from a pebble count in the downstream \nchannel, because the upstream channel is primarily bedrock. The geomorphic assessment at \nthe time of the Level I and Level II site visit on August 8, 1995, indicated that the reach was \nstable.\nThe Town Highway 18 crossing of the Coles Brook is a 46-ft-long, one-lane bridge \nconsisting of one 44-foot steel-beam span with a wooden deck (Vermont Agency of \nTransportation, written communication, April 5, 1995). The opening length of the structure \nparallel to the bridge face is 41.4 ft. The bridge is supported by a vertical, concrete abutment \nwith wingwalls on the left and by a vertical, stone abutment with stone wingwalls with a \nconcrete cap on the right. The channel is skewed approximately 5 degrees to the opening \nwhile the computed opening-skew-to-roadway is 10 degrees. \nThe only scour protection measure at the site was a stone wall along the upstream left bank \nand type-2 stone fill (less than 36 inches diameter) along the entire base length of the \nupstream left wingwall, left abutment, and downstream left wing wall. Additional details \ndescribing conditions at the site are included in the Level II Summary and Appendices D \nand E.\nScour depths and recommended rock rip-rap sizes were computed using the general \nguidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995) \nfor the 100-year and 500-year discharges. Total scour at a highway crossing is comprised of \nthree components: 1) long-term streambed degradation; 2) contraction scour (due to \naccelerated flow caused by a reduction in flow area at a bridge) and; 3) local scour (caused \nby accelerated flow around piers and abutments). Total scour is the sum of the three \ncomponents. Equations are available to compute depths for contraction and local scour and \na summary of the results of these computations follows.\nContraction scour for all modelled flows was 0.0 ft. Abutment scour ranged from 6.4 to 7.9 \nft at the left abutment and from 11.8 to 14.9 ft at the right abutment. The worst-case \nabutment scour occurred at the 500-year discharge. Additional information on scour depths \nand 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","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr97768","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Striker, L.K., and Ivanoff, M.A., 1997, Level II scour analysis for Bridge 22 (WALDTH00180022) on Town Highway 18, crossing Coles Brook, Walden, Vermont: U.S. Geological Survey Open-File Report 97-768, iv, 48 p., https://doi.org/10.3133/ofr97768.","productDescription":"iv, 48 p.","numberOfPages":"53","costCenters":[],"links":[{"id":176344,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97768.PNG"},{"id":279675,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0768/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Walden","otherGeospatial":"Coles Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.25,44.375 ], [ -72.25,44.5 ], [ -72.0,44.5 ], [ -72.0,44.375 ], [ -72.25,44.375 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b1ae4b07f02db6a810d","contributors":{"authors":[{"text":"Striker, Lora K.","contributorId":41481,"corporation":false,"usgs":true,"family":"Striker","given":"Lora","email":"","middleInitial":"K.","affiliations":[],"preferred":false,"id":240617,"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":240616,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":50005,"text":"ofr97770 - 1997 - Level II scour analysis for Bridge 8 (WELLTH00020008) on Town Highway 2, crossing Wells Brook, Wells, Vermont","interactions":[],"lastModifiedDate":"2013-12-17T15:28:52","indexId":"ofr97770","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-770","title":"Level II scour analysis for Bridge 8 (WELLTH00020008) on Town Highway 2, crossing Wells Brook, Wells, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nWELLTH00020008 on Town Highway 2 crossing the Wells Brook, Wells, 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 southwestern Vermont. The 14.4-mi2\n drainage area is in a predominantly rural and forested \nbasin. In the vicinity of the study site, the surface cover on the right overbanks is \npredominantly suburban while the immediate banks are vegetated with trees and brush. The \nleft bank upstream and downstream is predominantly pasture.\nIn the study area, the Wells Brook has an incised, straight channel with a slope of \napproximately 0.005 ft/ft, an average channel top width of 51 ft and an average bank height \nof 7 ft. The channel bed material ranges from gravel to boulder with a median grain size \n(D50) of 48.6 mm (0.159 ft). The geomorphic assessment at the time of the Level I and \nLevel II site visit on September 19, 1995, indicated that the reach was stable.\nThe Town Highway 2 crossing of the Wells Brook is a 35-ft-long, two-lane bridge \nconsisting of one 32-foot concrete span (Vermont Agency of Transportation, written \ncommunication, March 22, 1995). The opening length of the structure parallel to the bridge \nface is 31.7 ft. The bridge is supported by vertical, concrete abutments with wingwalls. The \nchannel is skewed approximately 10 degrees to the opening while the opening-skew-toroadway is 5 degrees. \nA scour hole 1.5 ft deeper than the mean thalweg depth was observed along the left \nabutment during the Level I assessment. The only scour protection measure at the site was \ntype-2 stone fill (less than 36 inches diameter) along the left bank upstream, and type-5 \n(placed stone wall) at the upstream end of the upstream left wingwall, at the downstream \nend of the downstream left wingwall, and along the downstream left bank. Additional \ndetails describing conditions at the site are included in the Level II Summary and \nAppendices D and E.\nScour depths and recommended rock rip-rap sizes were computed using the general \nguidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995) \nfor the 100- and 500-year discharges. In addition, the incipient roadway-overtopping \ndischarge is determined and analyzed as another potential worst-case scour scenario. Total \nscour at a highway crossing is comprised of three components: 1) long-term streambed \ndegradation; 2) contraction scour (due to accelerated flow caused by a reduction in flow \narea at a bridge) and; 3) local scour (caused by accelerated flow around piers and \nabutments). Total scour is the sum of the three components. Equations are available to \ncompute depths for contraction and local scour and a summary of the results of these \ncomputations follows.\nContraction scour for all modelled flows ranged from 0.0 to 0.8 ft. The worst-case \ncontraction scour occurred at the incipient roadway-overtopping discharge, which was less \nthan the 100-year discharge. Abutment scour ranged from 5.6 to 10.0 ft at the left abutment \nand from 3.1 to 4.2 ft at the right abutment. The worst-case abutment scour occurred at the \nincipient roadway-overtopping discharge at the left abutment. Additional information on \nscour depths and depths to armoring are included in the section titled “Scour Results”. \nScoured-streambed elevations, based on the calculated scour depths, are presented in tables \n1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour \ndepths were calculated assuming an infinite depth of erosive material and a homogeneous \nparticle-size distribution. \nUsually, computed scour depths are evaluated in combination with other information \nincluding (but not limited to) historical performance during flood events, the geomorphic \nstability assessment, existing scour protection measures, and the results of the hydraulic \nanalyses. Therefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr97770","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Striker, L.K., and Ivanoff, M.A., 1997, Level II scour analysis for Bridge 8 (WELLTH00020008) on Town Highway 2, crossing Wells Brook, Wells, Vermont: U.S. Geological Survey Open-File Report 97-770, iv, 51 p., https://doi.org/10.3133/ofr97770.","productDescription":"iv, 51 p.","numberOfPages":"56","costCenters":[],"links":[{"id":176713,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97770.PNG"},{"id":279673,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0770/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Wells","otherGeospatial":"Wells Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -73.25,43.375 ], [ -73.25,43.5 ], [ -73.125,43.5 ], [ -73.125,43.375 ], [ -73.25,43.375 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b16e4b07f02db6a5639","contributors":{"authors":[{"text":"Striker, Lora K.","contributorId":41481,"corporation":false,"usgs":true,"family":"Striker","given":"Lora","email":"","middleInitial":"K.","affiliations":[],"preferred":false,"id":240621,"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":240620,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ]}