This report provides the results of a detailed Level II analysis of scour potential at structure \nWALDTH00020007 on Town Highway 2 crossing Coles Brook, Walden, Vermont (figures \n1–8). Coles Brook is also referred to as Joes Brook. A Level II study is a basic engineering \nanalysis of the site, including a quantitative analysis of stream stability and scour (U.S. \nDepartment of Transportation, 1993). Results of a Level I scour investigation also are \nincluded in Appendix E of this report. A Level I investigation provides a qualitative \ngeomorphic characterization of the study site. Information on the bridge, gleaned from \nVermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level \nI and Level II analyses and is found in Appendix D.
\nThe site is in the New England Upland section of the New England physiographic province \nin north-eastern Vermont. The 12.8-mi2\n drainage area is in a predominantly rural and \nforested basin. In the vicinity of the study site, the surface cover is predominantly shrub and \nbrushland.
\nIn the study area, Coles Brook has a sinuous channel with a slope of approximately 0.005 ft/\nft, an average channel top width of 37 ft and an average bank height of 4 ft. The channel bed \nmaterial ranges from sand to cobble with a median grain size (D50) of 32.9 mm (0.108 ft). \nThe geomorphic assessment at the time of the Level I and Level II site visit on August 9, \n1995, indicated that the reach was laterally unstable due to cut-banks, point bars, and loose \nunconsolidated bed material.
\nThe Town Highway 2 crossing of Coles Brook is a 74-ft-long, two-lane bridge consisting of \none 71-foot steel-beam span (Vermont Agency of Transportation, written communication, \nApril 5, 1995). The opening length of the structure parallel to the bridge face is 69.3 ft. The \nbridge is supported by spill-through abutments. The channel is skewed approximately 35 \ndegrees to the opening while the measured opening-skew-to-roadway is 15 degrees.
\nA scour hole 1.5 ft deeper than the mean thalweg depth was observed from 60 ft. to 100 ft. \ndownstream during the Level I assessment. Scour protection measures at the site include: \ntype-1 stone fill (less than 12 inches diameter) along the right bank upstream, at the \ndownstream end of the downstream left wingwall and downstream right wingwall; and \ntype-2 stone fill (less than 36 inches diameter) along the left bank upstream, at the upstream \nend of the upstream right wingwall, and along the entire base of the left and right \nabutments. 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 incipient roadway-overtopping discharge. Abutment scour \nranged from 5.7 to 12.9 ft. The worst-case abutment scour occurred at the 500-year \ndischarge. Additional information on scour depths and depths to armoring are included in \nthe section titled “Scour Results”. Scoured-streambed elevations, based on the calculated \nscour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the \nbridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of \nerosive material and a homogeneous particle-size distribution.
\nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr97632","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 7 (WALDTH00020007) on Town Highway 2, crossing Coles Brook, Walden, Vermont: U.S. Geological Survey Open-File Report 97-632, iv, 51 p., https://doi.org/10.3133/ofr97632.","productDescription":"iv, 51 p.","numberOfPages":"56","costCenters":[],"links":[{"id":175736,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97632.GIF"},{"id":279708,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0632/report.pdf"}],"scale":"25000","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":"4f4e4b16e4b07f02db6a571f","contributors":{"authors":[{"text":"Striker, Lora K.","contributorId":41481,"corporation":false,"usgs":true,"family":"Striker","given":"Lora","email":"","middleInitial":"K.","affiliations":[],"preferred":false,"id":240561,"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":240560,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49968,"text":"ofr97628 - 1997 - Level II scour analysis for Bridge 31 (BRISTH00030031) on Town Highway 3, crossing the New Haven River, Bristol, Vermont","interactions":[],"lastModifiedDate":"2013-12-18T12:51:55","indexId":"ofr97628","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":"97-628","title":"Level II scour analysis for Bridge 31 (BRISTH00030031) on Town Highway 3, crossing the New Haven River, Bristol, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nBRISTH00030031 on Town Highway 3 crossing the New Haven River, Bristol, Vermont \n(figures 1–8). A Level II study is a basic engineering analysis of the site, including a \nquantitative analysis of stream stability and scour (U.S. Department of Transportation, \n1993). Results of a Level I scour investigation also are included in Appendix E of this \nreport. A Level I investigation provides a qualitative geomorphic characterization of the \nstudy site. Information on the bridge, gleaned from Vermont Agency of Transportation \n(VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is \nfound in Appendix D.
\nThe site is in the Green Mountain section of the New England physiographic province in \nwest-central, western Vermont. The 69.1-mi2\n drainage area is in a predominantly rural and \nforested basin. In the vicinity of the study site, the surface cover is forest except on the \ndownstream left overbank which has closely spaced houses with lawns.
\nIn the study area, the New Haven River has an incised, sinuous channel with a slope of \napproximately 0.01 ft/ft, an average channel top width of 136 ft and an average bank height \nof 13 ft. The channel bed material ranges from gravel to boulder with a median grain size \n(D50) of 233 mm (0.765 ft). The geomorphic assessment at the time of the Level I and Level \nII site visit on June 20, 1996, indicated that the reach was stable.
\nThe Town Highway 3 crossing of the New Haven River is a 105-ft-long, two-lane bridge \nconsisting of a 101-ft-long pony truss span (Vermont Agency of Transportation, written \ncommunication, November 30, 1995). The opening length of the structure parallel to the \nbridge face is 98 ft. The bridge is supported by vertical, concrete abutments with wingwalls. \nThe channel is skewed approximately 60 degrees to the opening, with no opening-skew-to-roadway.
\nA local scour hole 3 ft deeper than the mean thalweg depth was observed near the exit cross \nsection during the Level I assessment. Scour countermeasures included a stone wall on the \nupstream right bank, type-3 stone fill (less than 48 inches diameter) on the upstream and \ndownstream left banks, and type-2 stone fill (less than 36 inches diameter) on the \ndownstream end of the right abutment and on the downstream right 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.
\nThere was no contraction scour for any of the modelled flows. Abutment scour ranged from \n12.7 to 16.4 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 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/ofr97628","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Degnan, J.R., 1997, Level II scour analysis for Bridge 31 (BRISTH00030031) on Town Highway 3, crossing the New Haven River, Bristol, Vermont: U.S. Geological Survey Open-File Report 97-628, iv, 48 p., https://doi.org/10.3133/ofr97628.","productDescription":"iv, 48 p.","numberOfPages":"53","costCenters":[],"links":[{"id":175734,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97628.GIF"},{"id":279710,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0628/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Bristol","otherGeospatial":"New Haven 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":"4f4e4b19e4b07f02db6a7dcd","contributors":{"authors":[{"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":240557,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":49975,"text":"ofr97650 - 1997 - Level II scour analysis for Bridge 33 (CONCTH00580033) on Town Highway 58, crossing Miles Stream, Concord, Vermont","interactions":[],"lastModifiedDate":"2013-12-18T10:31:48","indexId":"ofr97650","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":"97-650","title":"Level II scour analysis for Bridge 33 (CONCTH00580033) on Town Highway 58, crossing Miles Stream, Concord, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nCONCTH00580033 on Town Highway 58 crossing Miles Stream, Concord, Vermont \n(figures 1–8). A Level II study is a basic engineering analysis of the site, including a \nquantitative analysis of stream stability and scour (U.S. Department of Transportation, \n1993). Results of a Level I scour investigation also are included in Appendix E of this \nreport. A Level I investigation provides a qualitative geomorphic characterization of the \nstudy site. Information on the bridge, gleaned from Vermont Agency of Transportation \n(VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is \nfound in Appendix D.
\nThe site is in the New England Upland section of the New England physiographic province \nin northeastern Vermont. The 17.9-mi2\n drainage area is in a predominantly rural and \nforested basin. In the vicinity of the study site, the surface cover is pasture upstream of the \nbridge while the immediate banks have dense woody vegetation. Downstream of the \nbridge, the right bank is forested and the left bank has shrubs and brush.
\nIn the study area, Miles Stream has an incised, sinuous channel with a slope of \napproximately 0.01 ft/ft, an average channel top width of 91 ft and an average bank height \nof 7 ft. The channel bed material ranges from gravel to boulder with a median grain size \n(D50) of 61.6 mm (0.188 ft). The geomorphic assessment at the time of the Level I and \nLevel II site visit on August 15, 1995, indicated that the reach was stable.
\nThe Town Highway 58 crossing of Miles Stream is a 44-ft-long, two-lane bridge consisting \nof one 39-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 37.4 ft. The bridge is supported by vertical, concrete abutments with stone fill in \nfront creating spillthrough embankments. The channel is skewed approximately 20 degrees \nto the opening while the opening-skew-to-roadway is zero degrees.
\nThe only scour countermeasure at the site was type-3 stone fill (less than 48 inches \ndiameter) along the left and right banks upstream, in front of the abutments forming spill \nthrough embankments, and extending along the banks downstream. 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- and 500-year discharges. In addition, the incipient roadway-overtopping \ndischarge is determined and analyzed as another potential worst-case scour scenario. Total \nscour at a highway crossing is comprised of three components: 1) long-term streambed \ndegradation; 2) contraction scour (due to accelerated flow caused by a reduction in flow \narea at a bridge) and; 3) local scour (caused by accelerated flow around piers and \nabutments). Total scour is the sum of the three components. Equations are available to \ncompute depths for contraction and local scour and a summary of the results of these \ncomputations follows.
\nContraction scour for all modelled flows ranged from 0.0 to 1.8 ft. The worst-case \ncontraction scour occurred at the 500-year discharge. Abutment scour ranged from 4.0 to \n9.7 ft. The worst-case abutment scour occurred at the 500-year discharge for the right \nabutment and at the incipient roadway-overtopping discharge for the left abutment. \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/ofr97650","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Burns, R.L., 1997, Level II scour analysis for Bridge 33 (CONCTH00580033) on Town Highway 58, crossing Miles Stream, Concord, Vermont: U.S. Geological Survey Open-File Report 97-650, iv, 51 p., https://doi.org/10.3133/ofr97650.","productDescription":"iv, 51 p.","numberOfPages":"56","costCenters":[],"links":[{"id":175841,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97650.GIF"},{"id":279703,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0650/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Concord","otherGeospatial":"Miles Stream","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.75,43.5 ], [ -72.75,43.625 ], [ -72.625,43.625 ], [ -72.625,43.5 ], [ -72.75,43.5 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a6528","contributors":{"authors":[{"text":"Burns, Ronda L.","contributorId":71602,"corporation":false,"usgs":true,"family":"Burns","given":"Ronda","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":240568,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":24769,"text":"ofr97421 - 1997 - A Graphical-User Interface for the U. S. Geological Survey's SUTRA Code using Argus ONE (for simulation of variable-density saturated-unsaturated ground-water flow with solute or energy transport)","interactions":[],"lastModifiedDate":"2012-02-02T00:15:57","indexId":"ofr97421","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":"97-421","title":"A Graphical-User Interface for the U. S. Geological Survey's SUTRA Code using Argus ONE (for simulation of variable-density saturated-unsaturated ground-water flow with solute or energy transport)","docAbstract":"This report describes a Graphical-User Interface (GUI) for SUTRA, the U.S. Geological Survey (USGS) model for saturated-unsaturated variable-fluid-density ground-water flow with solute or energy transport,which combines a USGS-developed code that interfaces SUTRA with Argus ONE, a commercial software product developed by Argus Interware. This product, known as Argus Open Numerical Environments (Argus ONETM), is a programmable system with geographic-information-system-like (GIS-like) functionality that includes automated gridding and meshing capabilities for linking geospatial information with finite-difference and finite-element numerical model discretizations. The GUI for SUTRA is based on a public-domain Plug-In Extension (PIE) to Argus ONE that automates the use of ArgusONE to: automatically create the appropriate geospatial information coverages (information layers) for SUTRA, provide menus and dialogs for inputting geospatial information and simulation control parameters for SUTRA, and allow visualization of SUTRA simulation results. Following simulation control data and geospatial data input bythe user through the GUI, ArgusONE creates text files in a format required for normal input to SUTRA,and SUTRA can be executed within the Argus ONE environment. Then, hydraulic head, pressure, solute concentration, temperature, saturation and velocity results from the SUTRA simulation may be visualized. Although the GUI for SUTRA discussed in this report provides all of the graphical pre- and post-processor functions required for running SUTRA, it is also possible for advanced users to apply programmable features within Argus ONE to modify the GUI to meet the unique demands of particular ground-water modeling projects.","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Reston, VA","doi":"10.3133/ofr97421","issn":"0094-9140","usgsCitation":"Voss, C.I., Boldt, D., and Shapiro, A.M., 1997, A Graphical-User Interface for the U. S. Geological Survey's SUTRA Code using Argus ONE (for simulation of variable-density saturated-unsaturated ground-water flow with solute or energy transport): U.S. Geological Survey Open-File Report 97-421, vi, 90 p.; Appendices; Index, https://doi.org/10.3133/ofr97421.","productDescription":"vi, 90 p.; Appendices; Index","startPage":"i","endPage":"106","numberOfPages":"112","costCenters":[{"id":494,"text":"Office of Groundwater","active":false,"usgs":true}],"links":[{"id":118751,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr_97_421.jpg"},{"id":53792,"rank":300,"type":{"id":15,"text":"Index Page"},"url":"https://pubs.usgs.gov/of/1997/0421/","linkFileType":{"id":5,"text":"html"}}],"noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"53cd4957e4b0b290850ef131","contributors":{"authors":[{"text":"Voss, Clifford I. 0000-0001-5923-2752 cvoss@usgs.gov","orcid":"https://orcid.org/0000-0001-5923-2752","contributorId":1559,"corporation":false,"usgs":true,"family":"Voss","given":"Clifford","email":"cvoss@usgs.gov","middleInitial":"I.","affiliations":[{"id":438,"text":"National Research Program - Western Branch","active":true,"usgs":true}],"preferred":true,"id":192530,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Boldt, David","contributorId":55143,"corporation":false,"usgs":true,"family":"Boldt","given":"David","affiliations":[],"preferred":false,"id":192532,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Shapiro, Allen M. 0000-0002-6425-9607 ashapiro@usgs.gov","orcid":"https://orcid.org/0000-0002-6425-9607","contributorId":2164,"corporation":false,"usgs":true,"family":"Shapiro","given":"Allen","email":"ashapiro@usgs.gov","middleInitial":"M.","affiliations":[{"id":436,"text":"National Research Program - Eastern Branch","active":true,"usgs":true},{"id":37277,"text":"WMA - Earth System Processes Division","active":true,"usgs":true}],"preferred":true,"id":192531,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":49912,"text":"ofr97340 - 1997 - Level II scour analysis for Bridge 29 (HARDTH00310029) on Town Highway 31, crossing the Lamoille River, Hardwick, Vermont","interactions":[],"lastModifiedDate":"2014-01-05T13:36:25","indexId":"ofr97340","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":"97-340","title":"Level II scour analysis for Bridge 29 (HARDTH00310029) on Town Highway 31, crossing the Lamoille River, Hardwick, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nHARDTH00310029 on town highway 31 crossing the Lamoille River, Hardwick, Vermont \n(figures 1–8). A Level II study is a basic engineering analysis of the site, including a \nquantitative analysis of stream stability and scour (U.S. Department of Transportation, \n1993). Results of a Level I scour investigation also are included in Appendix E of this \nreport. A Level I investigation provides a qualitative geomorphic characterization of the \nstudy site. Information on the bridge, gleaned from Vermont Agency of Transportation \n(VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is \nfound in Appendix D.
\nThe site is in the New England Upland section of the New England physiographic province \nof north-central Vermont. The 64.4-mi2\n drainage area is in a predominantly rural basin. In \nthe vicinity of the study site, the surface cover is pasture except for the immediate \ndownstream channel banks and the downstream left overbank which are brush covered.
\nIn the study area, the Lamoille River has a sinuous channel with a slope of approximately \n0.001 ft/ft, an average channel top width of 84 ft and an average channel depth of 4 ft. The \npredominant channel bed materials are cobble and gravel with a median grain size (D50) of \n36.1 mm (0.119 ft). The geomorphic assessment at the time of the Level I and Level II site \nvisit on July 26, 1995, indicated that the reach was stable.
\nThe town highway 31 crossing of the Lamoille River is a 65-ft-long, one-lane bridge \nconsisting of one 61-foot steel-beam span (Vermont Agency of Transportation, written \ncommunication, March 27, 1995). The bridge is supported by vertical, stone abutments with \nwingwalls. The right abutment has a concrete facing and a concrete subfooter. The channel \nis skewed approximately 5 degrees to the opening while the opening-skew-to-roadway is 0 \ndegrees. Additional details describing conditions at the site are included in the Level II \nSummary and Appendices D \nand E.
\nScour depths and rock rip-rap sizes were computed using the general guidelines described \nin Hydraulic Engineering Circular 18 (Richardson and others, 1995). Total scour at a \nhighway crossing is comprised of three components: 1) long-term streambed degradation; \n2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) \nand; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is \nthe sum of the three components. Equations are available to compute depths for contraction \nand local scour and a summary of the results of these computations follows.
\nContraction scour for all modelled flows ranged from 0.0 to 2.7 ft. The worst-case \ncontraction scour occurred at the 500-year discharge. Abutment scour ranged from 10.3 to \n18.6 ft. The worst-case abutment scour occurred at the 100-year discharge at the right \nabutment. Additional information on scour depths and depths to armoring are included in \nthe section titled “Scour Results”. Scoured-streambed elevations, based on the calculated \nscour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the \nbridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of \nerosive material and a homogeneous particle-size distribution.
\nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr97340","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Olson, S.A., 1997, Level II scour analysis for Bridge 29 (HARDTH00310029) on Town Highway 31, crossing the Lamoille River, Hardwick, Vermont: U.S. Geological Survey Open-File Report 97-340, iv, 50 p., https://doi.org/10.3133/ofr97340.","productDescription":"iv, 50 p.","numberOfPages":"55","costCenters":[],"links":[{"id":169721,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97340.GIF"},{"id":279773,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0340/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Hardwick","otherGeospatial":"Lamoille River","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.375,44.5 ], [ -72.375,44.625 ], [ -72.25,44.625 ], [ -72.25,44.5 ], [ -72.375,44.5 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b19e4b07f02db6a7f3a","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":240466,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":49905,"text":"ofr97216 - 1997 - Level II scour analysis for Bridge 6 (STAMVT01000006) on State Route 100, crossing the North Branch of the Hoosic River, Stamford, Vermont","interactions":[],"lastModifiedDate":"2013-12-20T10:08:56","indexId":"ofr97216","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":"97-216","title":"Level II scour analysis for Bridge 6 (STAMVT01000006) on State Route 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 STAMVT01000006 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 8.61-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is grass with forest along the immediate banks throughout the reach.\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 44 ft and an average bank height of 4 ft. The channel bed material ranges from sand to boulder with a median grain size (D50) of 97.4 mm (0.320 ft). The geomorphic assessment at the time of the Level I and Level II site visit on July 31, 1996, indicated that the reach was stable.\nThe Vermont Highway 100 crossing of the North Branch of the Hoosic River is a 99-ft-long, two-lane bridge consisting of one 97-foot steel-beam span (Vermont Agency of Transportation, written communication, September 28, 1995). The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 60 degrees to the opening and the opening-skew-to-roadway is also 60 degrees.\nThe scour protection measures at the site included type-1 stone fill (less than 12 inches diameter) along the downstream left bank. Type-2 (less than 36 inches diameter) stone fill was found along the upstream left bank and the downsteam right bank. 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 0.7 to 2.1 ft. The worst-case contraction scour occurred at the 500-year discharge. Abutment scour ranged from 18.8 to 19.7 ft along the right abutment and from 2.8 to 6.8 ft along the left abutment. 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/ofr97216","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Flynn, R.H., 1997, Level II scour analysis for Bridge 6 (STAMVT01000006) on State Route 100, crossing the North Branch of the Hoosic River, Stamford, Vermont: U.S. Geological Survey Open-File Report 97-216, iv, 50 p., https://doi.org/10.3133/ofr97216.","productDescription":"iv, 50 p.","numberOfPages":"55","costCenters":[],"links":[{"id":169643,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97216.PNG"},{"id":279780,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0216/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":"4f4e4b17e4b07f02db6a5c92","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":240455,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":49911,"text":"ofr97339 - 1997 - Level II scour analysis for Bridge 7H (HUNTTH0001007H) on Town Highway 1, crossing Cobb Brook, Huntington, Vermont","interactions":[],"lastModifiedDate":"2016-08-25T13:24:34","indexId":"ofr97339","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":"97-339","title":"Level II scour analysis for Bridge 7H (HUNTTH0001007H) on Town Highway 1, crossing Cobb Brook, Huntington, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure HUNTTH001007H on Town Highway 1 crossing the Cobb Brook, Huntington, Vermont (figures 1–10). 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.
In August 1976, Hurricane Belle caused flooding at this site which resulted in road and bridge damage (figures 7-8). This was approximately a 25-year flood event (U.S. Department of Housing and Urban Development, 1978). The site is in the Green Mountain section of the New England physiographic province in central Vermont. The 4.20-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is forest upstream of the bridge. Downstream of the bridge is brushland and pasture.
In the study area, the Cobb Brook has an incised, straight channel with a slope of approximately 0.03 ft/ft, an average channel top width of 43 ft and an average bank height of 6 ft. The channel bed material ranges from sand to boulders with a median grain size (D50) of 65.5 mm (0.215 ft). The geomorphic assessment at the time of the Level I and Level II site visit on June 24, 1996, indicated that the reach was stable.
The Town Highway 1 crossing of the Cobb Brook is a 23-ft-long, two-lane bridge consisting of one 20-foot concrete slab span (Vermont Agency of Transportation, written communication, June 21, 1996). The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 15 degrees to the opening while the opening-skew-to-roadway is zero degrees.
A scour hole 2.8 ft deeper than the mean thalweg depth was observed along the left abutment during the Level I assessment. Protection measures at the site include type-1 stone fill (less than 12 inches diameter) at the downstream right wingwall, type-2 stone fill (less than 36 inches diameter) at the upstream right wingwall and the downstream end of the downstream left wingwall, and type-3 stone fill (less than 48 inches diameter) at the upstream left wingwall. Additional details describing conditions at the site are included in the Level II Summary and Appendices D and E.
Scour depths and recommended rock rip-rap sizes were computed using the general guidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995). Total scour at a highway crossing is comprised of three components: 1) long-term streambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is the sum of the three components. Equations are available to compute depths for contraction and local scour and a summary of the results of these computations follows.
Contraction scour for all modelled flows ranged from 0.2 to 1.3 ft. The worst-case contraction scour occurred at the incipient-overtopping discharge. Abutment scour ranged from 4.0 to 8.7 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 10. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution.
It is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, computed scour depths are evaluated in combination with other information including (but not limited to) historical performance during flood events, the geomorphic stability assessment, existing scour protection measures, and the results of the hydraulic analyses. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr97339","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Wild, E.C., 1997, Level II scour analysis for Bridge 7H (HUNTTH0001007H) on Town Highway 1, crossing Cobb Brook, Huntington, Vermont: U.S. Geological Survey Open-File Report 97-339, iv, 51 p., https://doi.org/10.3133/ofr97339.","productDescription":"iv, 51 p.","numberOfPages":"56","costCenters":[],"links":[{"id":169720,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97339.JPG"},{"id":279774,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0339/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Huntington","otherGeospatial":"Cobb 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":"4f4e4b16e4b07f02db6a5692","contributors":{"authors":[{"text":"Wild, Emily C. 0000-0001-6157-7629 ecwild@usgs.gov","orcid":"https://orcid.org/0000-0001-6157-7629","contributorId":1810,"corporation":false,"usgs":true,"family":"Wild","given":"Emily","email":"ecwild@usgs.gov","middleInitial":"C.","affiliations":[{"id":5081,"text":"Libraries","active":false,"usgs":true}],"preferred":false,"id":240465,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":49957,"text":"ofr97576 - 1997 - Level II scour analysis for Bridge 26 (WSTOTH00070026) on Town Highway 7, crossing Greendale Brook, Weston, Vermont","interactions":[],"lastModifiedDate":"2013-12-18T15:20:51","indexId":"ofr97576","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":"97-576","title":"Level II scour analysis for Bridge 26 (WSTOTH00070026) on Town Highway 7, crossing Greendale Brook, Weston, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nWSTOTH00070026 on Town Highway 7 crossing Greendale Brook, Weston, 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 3.13-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, the Greendale Brook has a sinuous, non-incised, non-alluvial channel with \na slope of approximately 0.015 ft/ft, an average channel top width of 38 ft and an average \nbank height of 3 ft. The channel bed material ranges from sand to boulder with a median \ngrain size (D50) of 64.8 mm (0.213 ft). The geomorphic assessment at the time of the Level \nI and Level II site visit on August 19, 1996, indicated that the reach was laterally unstable. \nThe channel has moved to the right, however, scour countermeasures are in place along the \nupstream right bank.
\nThe Town Highway 7 crossing of the Greendale Brook is a 52-ft-long, two-lane bridge \nconsisting of one 50-foot steel-beam span with a concrete deck (Vermont Agency of \nTransportation, written communication, April 07, 1995). The opening length of the \nstructure parallel to the bridge face is 48.6 ft. The bridge is supported by vertical, concrete \nabutments with wingwalls. The channel is skewed approximately 50 degrees to the opening \nwhile the opening-skew-to-roadway is 30 degrees.
\nA scour hole 1.5 ft deeper than the mean thalweg depth was observed along the upstream \nright wingwall and right abutment during the Level I assessment. Scour protection measures \nat the site include: type-2 stone fill (less than 36 inches diameter) at the upstream end of the \nupstream left wingwall, along the left bank upstream, at the downstream end of the \ndownstream left wing wall, and along the entire length of the downstream right wing wall; \ntype 4 (less than 60 inches) and type-3 stone fill (less than 48 inches) along the right bank \nupstream. 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 was 0.0 ft. Abutment scour ranged from 3.9 to 9.9 \nft. 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). The Hire \nequation (abutment scour) is often used when the horizontal length blocked by flow divided \nby the depth of flow is greater than 25 (Richardson and others, 1995 p. 49). Although the \nHire equation could be applied to the left abutment more conservative scour estimates were \ngiven by the Froehlich equation on the left abutment. Usually, computed scour depths are \nevaluated in combination with other information including (but not limited to) historical \nperformance during flood events, the geomorphic stability assessment, existing scour \nprotection measures, and the results of the hydraulic analyses. Therefore, scour depths \nadopted by VTAOT may differ from the computed values documented herein.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr97576","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Striker, L.K., and Hammond, R., 1997, Level II scour analysis for Bridge 26 (WSTOTH00070026) on Town Highway 7, crossing Greendale Brook, Weston, Vermont: U.S. Geological Survey Open-File Report 97-576, iv, 48 p., https://doi.org/10.3133/ofr97576.","productDescription":"iv, 48 p.","numberOfPages":"53","costCenters":[],"links":[{"id":175616,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97576.GIF"},{"id":279725,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0576/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Weston","otherGeospatial":"Greendale Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.875,43.25 ], [ -72.875,43.375 ], [ -72.75,43.375 ], [ -72.75,43.25 ], [ -72.875,43.25 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b1ae4b07f02db6a7ff6","contributors":{"authors":[{"text":"Striker, Lora K.","contributorId":41481,"corporation":false,"usgs":true,"family":"Striker","given":"Lora","email":"","middleInitial":"K.","affiliations":[],"preferred":false,"id":240538,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Hammond, Robert A.","contributorId":24677,"corporation":false,"usgs":true,"family":"Hammond","given":"Robert A.","affiliations":[],"preferred":false,"id":240537,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49959,"text":"ofr97580 - 1997 - Level II scour analysis for Bridge 10 (BENNUS00070010) on U.S. Route 7, crossing the Walloomsac River, Bennington, Vermont","interactions":[],"lastModifiedDate":"2013-12-18T14:51:06","indexId":"ofr97580","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":"97-580","title":"Level II scour analysis for Bridge 10 (BENNUS00070010) on U.S. Route 7, crossing the Walloomsac River, Bennington, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nBENNUS00070010 on U.S. Route 7, also known as North Street, crossing of the \nWalloomsac River, Bennington, 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 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, parking lots, lawns, and a playground on the overbank areas.
\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 37 ft and an average bank height \nof 5 ft. The predominant channel bed material is cobble with a median grain size (D50) of \n96.0 mm (0.315 ft). The geomorphic assessment at the time of the Level I and Level II site \nvisit on August 5, 1996, indicated that the constructed reach was stable.
\nThe U.S. Route 7 crossing of the Walloomsac River is a 53-ft-long, two-lane bridge \nconsisting of one 50-foot steel span (Vermont Agency of Transportation, written \ncommunication, September 27, 1995). The bridge is supported by vertical, concrete \nabutments with wingwalls. The wingwalls are angled in toward the channel because the \nwidths of the upstream and downstream constructed channel banks are narrower than the \nbridge opening. The channel is skewed approximately 5 degrees to the opening and the \nopening-skew-to-roadway is 10 degrees.
\nScour countermeasures at the site include masonry and stone walls on both the upstream \nand downstream banks. Additional details describing conditions at the site are included in \nthe Level II Summary and Appendices D and E.
\nScour depths and 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 0.1 ft. The worstcase contraction scour occurred at the 500-year discharge. Computed left abutment scour \nranged from 5.9 to 6.8 ft. with the worst-case scour occurring at the 500-year discharge. \nComputed right abutment scour for all modelled flows was 6.8 ft. Total scour depths for all \nmodelled flows did not exceed the depth of the abutment footings. Additional information \non scour depths and depths to armoring are included in the section titled “Scour Results”. \nScoured-streambed elevations, based on the calculated scour depths, are presented in tables \n1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour \ndepths were calculated assuming an infinite depth of erosive material and a homogeneous \nparticle-size distribution.
\nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 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/ofr97580","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Olson, S.A., and Burns, R.L., 1997, Level II scour analysis for Bridge 10 (BENNUS00070010) on U.S. Route 7, crossing the Walloomsac River, Bennington, Vermont: U.S. Geological Survey Open-File Report 97-580, iv, 50 p., https://doi.org/10.3133/ofr97580.","productDescription":"iv, 50 p.","numberOfPages":"55","costCenters":[],"links":[{"id":175618,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97580.GIF"},{"id":279719,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0580/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":"4f4e4b1ae4b07f02db6a849b","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":240541,"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":240542,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":50023,"text":"ofr97799 - 1997 - Level II scour analysis for Bridge 21 (WALDTH00450021) on Town Highway 45, crossing Joes Brook, Walden, Vermont","interactions":[],"lastModifiedDate":"2017-10-18T12:36:29","indexId":"ofr97799","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":"97-799","title":"Level II scour analysis for Bridge 21 (WALDTH00450021) on Town Highway 45, crossing Joes Brook, Walden, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nWALDTH00450021 on Town Highway 45 crossing Joes Brook, Walden, 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. The VTAOT files state that the stream is Coles Brook, both the USGS and the \nVTAOT maps state that it is Joes Brook.\nThe site is in the New England Upland section of the New England physiographic province \nin central Vermont. The 18.7-mi2\n 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, Joes Brook has an incised, sinuous channel with a slope of approximately \n0.01 ft/ft, an average channel top width of 76 ft and an average bank height of 5 ft. The \nchannel bed material ranges from sand to boulder with a median grain size (D50) of 75.4 \nmm (0.247 ft). The geomorphic assessment at the time of the Level I and Level II site visit \non July 27, 1995, indicated that the reach was stable.\nThe Town Highway 45 crossing of Joes Brook is a 35-ft-long, one-lane bridge consisting of \none 29-foot steel-beam span with a wooden deck (Vermont Agency of Transportation, \nwritten communication, April 5, 1995). The opening length of the structure parallel to the \nbridge face is 26.2 ft. The bridge is supported by vertical, “laid-up” concrete block \nabutments with no wingwalls. The channel is skewed approximately zero degrees to the \nopening while the computed opening-skew-to-roadway is 5 degrees.\nThe scour protection measures at the site included type-1 stone fill (less than 12 inches \ndiameter) along the upstream left bank and along the entire base length of the left abutment. \nThere is also type-2 stone fill (less than 36 inches diameter) along the entire base length of \nthe right abutment. Additional details describing conditions at the site are included in the \nLevel 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- and 500-year discharges. In addition, the incipient roadway-overtopping \ndischarge is determined and analyzed as another potential worst-case scour scenario. Total \nscour at a highway crossing is comprised of three components: 1) long-term streambed \ndegradation; 2) contraction scour (due to accelerated flow caused by a reduction in flow \narea at a bridge) and; 3) local scour (caused by accelerated flow around piers and \nabutments). Total scour is the sum of the three components. Equations are available to \ncompute depths for contraction and local scour and a summary of the results of these \ncomputations follows.\nContraction scour for all modelled flows ranged from 0.0 to 1.5 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 12.4 to 24.4 ft. 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/ofr97799","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 21 (WALDTH00450021) on Town Highway 45, crossing Joes Brook, Walden, Vermont: U.S. Geological Survey Open-File Report 97-799, iv, 52 p., https://doi.org/10.3133/ofr97799.","productDescription":"iv, 52 p.","numberOfPages":"57","costCenters":[],"links":[{"id":161570,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97799.PNG"},{"id":279640,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0799/report.pdf"}],"scale":"25000","country":"United States","state":"Vermont","city":"Walden","otherGeospatial":"Joes 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":"4f4e4b1ae4b07f02db6a81f5","contributors":{"authors":[{"text":"Ivanoff, Michael A.","contributorId":27105,"corporation":false,"usgs":true,"family":"Ivanoff","given":"Michael","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":240654,"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":240653,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":50025,"text":"ofr97803 - 1997 - Level II scour analysis for Bridge 33 (TUNBTH00450033) on Town Highway 45, crossing the First Branch White River, Tunbridge, Vermont","interactions":[],"lastModifiedDate":"2016-08-25T15:51:00","indexId":"ofr97803","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":"97-803","title":"Level II scour analysis for Bridge 33 (TUNBTH00450033) on Town Highway 45, crossing the First Branch White River, Tunbridge, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure TUNBTH00450033 on Town Highway 45 crossing the First Branch White River, Tunbridge, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including a quantitative analysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of a Level I scour investigation also are included in Appendix E of this report. A Level I investigation provides a qualitative geomorphic characterization of the study site. Information on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is found in Appendix D.
The site is in the New England Upland section of the New England physiographic province in central Vermont. The 86.4-mi 2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is pasture upstream and downstream of the bridge, while woody vegetation sparsely covers the immediate banks.
In the study area, the First Branch White River has an incised, sinuous channel with a slope of approximately 0.003 ft/ft, an average channel top width of 68 ft and an average bank height of 7 ft. The channel bed material ranges from sand to gravel with a median grain size (D50) of 27.1 mm (0.089 ft). The geomorphic assessment at the time of the Level I and Level II site visit on October 18, 1995, indicated that the reach was laterally unstable due to a cut-bank present on the upstream right bank and a wide channel bar in the upstream reach.
The Town Highway 45 crossing of the First Branch White River is a 67-ft-long, one-lane bridge consisting of one 54-foot timber thru-truss span (Vermont Agency of Transportation, written communication, March 23, 1995). The opening length of the structure parallel to the bridge face is 53.5 ft. The bridge is supported on the right by a vertical, concrete abutment with an upstream wingwall, and on the left by a vertical, stone abutment. The channel is skewed approximately 20 degrees to the opening while the computed opening-skew-to-roadway is 10 degrees.
A scour hole 1.5 ft deeper than the mean thalweg depth was observed along the right abutment during the Level I assessment. Scour countermeasures at the site include type-1 stone fill (less than 12 inches diameter) along the upstream right wingwall, type-2 stone fill (less than 36 inches diameter) along the right abutment, and type-3 stone fill (less than 48 inches diameter) along the upstream right bank. Additional details describing conditions at the site are included in the Level II Summary and Appendices D and E.
Scour depths and recommended rock rip-rap sizes were computed using the general guidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995) for the 100- and 500-year discharges. In addition, the incipient roadway-overtopping discharge was determined and analyzed as another potential worst-case scour scenario. Total scour at a highway crossing is comprised of three components: 1) long-term streambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is the sum of the three components. Equations are available to compute depths for contraction and local scour and a summary of the results of these computations follows.
Contraction scour for all modelled flows ranged from 0.0 to 3.0 ft. The worst-case contraction scour occurred at the 500-year discharge. Left abutment scour ranged from 12.8 to 31.0 ft. Right abutment scour ranged from 9.8 to 19.0 ft. The worst-case left and right abutment scour occurred at the 500-year discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in Tables 1 and 2. A cross-section of the scour computed at the bridge is presented in Figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution.
It is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, computed scour depths are evaluated in combination with other information including (but not limited to) historical performance during flood events, the geomorphic stability assessment, existing scour protection measures, and the results of the hydraulic analyses. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Reston, VA","doi":"10.3133/ofr97803","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and the Federal Highway Administration","usgsCitation":"Wild, E., and Severance, T., 1997, Level II scour analysis for Bridge 33 (TUNBTH00450033) on Town Highway 45, crossing the First Branch White River, Tunbridge, Vermont: U.S. Geological Survey Open-File Report 97-803, iv, 52 p., https://doi.org/10.3133/ofr97803.","productDescription":"iv, 52 p.","additionalOnlineFiles":"N","costCenters":[],"links":[{"id":161572,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97803.JPG"},{"id":279659,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0803/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Tunbridge","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -7.035,43.01527777777778 ], [ -7.035,0.0011111111111111111 ], [ -72.5,0.0011111111111111111 ], [ -72.5,43.01527777777778 ], [ -7.035,43.01527777777778 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b18e4b07f02db6a6881","contributors":{"authors":[{"text":"Wild, E.C. 0000-0001-6157-7629","orcid":"https://orcid.org/0000-0001-6157-7629","contributorId":71227,"corporation":false,"usgs":true,"family":"Wild","given":"E.C.","affiliations":[{"id":5081,"text":"Libraries","active":false,"usgs":true}],"preferred":false,"id":240657,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Severance, Timothy","contributorId":104927,"corporation":false,"usgs":true,"family":"Severance","given":"Timothy","email":"","affiliations":[],"preferred":false,"id":240658,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49964,"text":"ofr97593 - 1997 - Level II scour analysis for Bridge 13 (SHARTH00040013) on Town Highway 4, crossing Broad Brook, Sharon, Vermont","interactions":[],"lastModifiedDate":"2016-08-25T16:06:05","indexId":"ofr97593","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":"97-593","title":"Level II scour analysis for Bridge 13 (SHARTH00040013) on Town Highway 4, crossing Broad Brook, Sharon, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure SHARTH00040013 on Town Highway 4 crossing Broad Brook, Sharon, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including a quantitative analysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of a Level I scour investigation also are included in Appendix E of this report. A Level I investigation provides a qualitative geomorphic characterization of the study site. Information on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is found in Appendix D.
The site is in the New England Upland section of the New England physiographic province in central Vermont. The 16.6-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is brushland on the downstream left overbank and row crops on the right overbank, while the immediate banks have dense woody vegetation. Upstream of the bridge, the overbanks are forested.
In the study area, Broad Brook has an incised, sinuous channel with a slope of approximately 0.02 ft/ft, an average channel top width of 69 ft and an average bank height of 5 ft. The channel bed material ranges from sand to boulder with a median grain size (D50) of 112 mm (0.369 ft). The geomorphic assessment at the time of the Level I site visit on April 11, 1995 and Level II site visit on July 23, 1996, indicated that the reach was stable.
The Town Highway 4 crossing of Broad Brook is a 34-ft-long, two-lane bridge consisting of one 31-foot concrete tee beam span (Vermont Agency of Transportation, written communication, March 23, 1995). The opening length of the structure parallel to the bridge face is 30.1 ft. The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 10 degrees to the opening while the opening-skew-to-roadway is 15 degrees.
A scour hole 2.0 ft deeper than the mean thalweg depth was observed along the upstream end of the right abutment. At the downstream end of the left abutment, a 1.0 foot scour hole was observed . Scour countermeasures at the site include type-2 stone fill (less than 3 feet diameter) at each road embankment. Additional details describing conditions at the site are included in the Level II Summary and Appendices D and E.
Scour depths and recommended rock rip-rap sizes were computed using the general guidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995). Total scour at a highway crossing is comprised of three components: 1) long-term streambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is the sum of the three components. Equations are available to compute depths for contraction and local scour and a summary of the results of these computations follows.
Contraction scour for all modelled flows ranged from 0.7 to 1.8 ft. The worst-case contraction scour occurred at the 500-year discharge. Left abutment scour ranged from 5.6 to 9.4 ft. The worst case left abutment scour occurred at the 500-year discharge. Right abutment scour ranged from 19.0 to 19.8 ft. The worst-case right abutment scour occurred at the incipient-overtopping discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution.
It is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, computed scour depths are evaluated in combination with other information including (but not limited to) historical performance during flood events, the geomorphic stability assessment, existing scour protection measures, and the results of the hydraulic analyses. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr97593","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Wild, E.C., and Weber, M.A., 1997, Level II scour analysis for Bridge 13 (SHARTH00040013) on Town Highway 4, crossing Broad Brook, Sharon, Vermont: U.S. Geological Survey Open-File Report 97-593, iv, 52 p., https://doi.org/10.3133/ofr97593.","productDescription":"iv, 52 p.","numberOfPages":"57","costCenters":[],"links":[{"id":175730,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97593.GIF"},{"id":279714,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0593/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Sharon","otherGeospatial":"Broad 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":"4f4e4b1ae4b07f02db6a8330","contributors":{"authors":[{"text":"Wild, Emily C. 0000-0001-6157-7629 ecwild@usgs.gov","orcid":"https://orcid.org/0000-0001-6157-7629","contributorId":1810,"corporation":false,"usgs":true,"family":"Wild","given":"Emily","email":"ecwild@usgs.gov","middleInitial":"C.","affiliations":[{"id":5081,"text":"Libraries","active":false,"usgs":true}],"preferred":false,"id":240550,"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":240551,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49981,"text":"ofr97661 - 1997 - Level II scour analysis for Bridge 36 (DUXBTH00040036) on Town Highway 4, crossing Crossett Brook, Duxbury, Vermont","interactions":[],"lastModifiedDate":"2016-08-25T14:49:07","indexId":"ofr97661","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":"97-661","title":"Level II scour analysis for Bridge 36 (DUXBTH00040036) on Town Highway 4, crossing Crossett Brook, Duxbury, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure DUXBTH00040036 on Town Highway 4 crossing the Crossett Brook, Duxbury, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including a quantitative analysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of a Level I scour investigation also are included in Appendix E of this report. A Level I investigation provides a qualitative geomorphic characterization of the study site. Information on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is found in Appendix D.
The site is in the Green Mountain section of the New England physiographic province in north-central Vermont. The 4.9-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover on the upstream left overbank is pasture. The upstream and downstream right overbanks are forested. The downstream left overbank is brushland, while the immediate banks have dense woody vegetation.
In the study area, the Crossett Brook has an incised, sinuous channel with a slope of approximately 0.006 ft/ft, an average channel top width of 55 ft and an average bank height of 9 ft. The channel bed material ranges from gravel to bedrock with a median grain size (D50) of 51.6 mm (0.169 ft). The geomorphic assessment at the time of the Level I and Level II site visit on July 1, 1996, indicated that the reach was stable.
The Town Highway 4 crossing of the Crossett Brook is a 29-ft-long, two-lane bridge consisting of a 26-foot concrete slab span (Vermont Agency of Transportation, written communication, October 13, 1995). The opening length of the structure parallel to the bridge face is 26 ft. The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 35 degrees to the opening while the computed opening-skew-to-roadway is 5 degrees.
A scour hole 1.5 ft deeper than the mean thalweg depth was observed along the upstream left wingwall and the right abutment during the Level I assessment. Scour countermeasures at the site includes type-2 stone fill (less than 36 inches diameter) at the upstream end of the upstream left and right wingwalls and the upstream left and right banks and road embankments. Additional details describing conditions at the site are included in the Level II Summary and Appendices D and E.
Scour depths and recommended rock rip-rap sizes were computed using the general guidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995). Total scour at a highway crossing is comprised of three components: 1) long-term streambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is the sum of the three components. Equations are available to compute depths for contraction and local scour and a summary of the results of these computations follows.
Contraction scour for all modelled flows ranged from 0.0 to 1.7 ft. The worst-case contraction scour occurred at the 500-year discharge. Left abutment scour ranged from 6.4 to 8.3 ft. Right abutment scour ranged from 6.0 to 7.0 ft. The worst-case left and right abutment scour occurred at the 500-year discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution.
It is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, computed scour depths are evaluated in combination with other information including (but not limited to) historical performance during flood events, the geomorphic stability assessment, existing scour protection measures, and the results of the hydraulic analyses. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr97661","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Wild, E.C., and Degnan, J.R., 1997, Level II scour analysis for Bridge 36 (DUXBTH00040036) on Town Highway 4, crossing Crossett Brook, Duxbury, Vermont: U.S. Geological Survey Open-File Report 97-661, iv, 48 p., https://doi.org/10.3133/ofr97661.","productDescription":"iv, 48 p.","numberOfPages":"53","costCenters":[],"links":[{"id":176148,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97661.GIF"},{"id":279697,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0661/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Duxbury","otherGeospatial":"Crossett Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -73.125,44.375 ], [ -73.125,44.5 ], [ -73.0,44.5 ], [ -73.0,44.375 ], [ -73.125,44.375 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a63d8","contributors":{"authors":[{"text":"Wild, Emily C. 0000-0001-6157-7629 ecwild@usgs.gov","orcid":"https://orcid.org/0000-0001-6157-7629","contributorId":1810,"corporation":false,"usgs":true,"family":"Wild","given":"Emily","email":"ecwild@usgs.gov","middleInitial":"C.","affiliations":[{"id":5081,"text":"Libraries","active":false,"usgs":true}],"preferred":false,"id":240578,"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":240577,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49879,"text":"ofr97104 - 1997 - Level II scour analysis for Bridge 8 (DANVTH00020008) on Town Highway 2, crossing the Morrill Brook, Danville, Vermont","interactions":[],"lastModifiedDate":"2014-01-07T11:21:33","indexId":"ofr97104","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":"97-104","title":"Level II scour analysis for Bridge 8 (DANVTH00020008) on Town Highway 2, crossing the Morrill Brook, Danville, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nDANVTH00020008 on Town Highway 2 crossing Morrill Brook, Danville, Vermont \n(figures 1–8). A Level II study is a basic engineering analysis of the site, including a \nquantitative analysis of stream stability and scour (U.S. Department of Transportation, \n1993). Results of a Level I scour investigation also are included in Appendix E of this \nreport. A Level I investigation provides a qualitative geomorphic characterization of the \nstudy site. Information on the bridge, gleaned from Vermont Agency of Transportation \n(VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is \nfound in Appendix D.\nThe site is in the New England Upland section of the New England physiographic province \nin North-East Vermont. The 4.74-mi2\n drainage area is in a predominantly rural and forested \nbasin. In the vicinity of the study site, the surface cover is forest with a residence on the \nupstream right bank. \nIn the study area, Morrill Brook has an incised, sinuous channel with a slope of \napproximately 0.03 ft/ft, an average channel top width of 60 ft and an average channel \ndepth of 8 ft. The predominant channel bed material is cobble with a median grain size \n(D50) of 67.0 mm (0.220 ft). The geomorphic assessment at the time of the Level I and \nLevel II site visit on September 9, 1995, indicated that the reach was stable.\nThe Town Highway 2 crossing of Morrill Brook is a 59-ft-long, two-lane bridge consisting \nof one 57-foot steel-beam span (Vermont Agency of Transportation, written \ncommunication, March 24, 1995). The bridge is supported by vertical, concrete abutments. \nThe channel is skewed approximately 5 degrees to the opening while the opening-skew-toroadway is 0 degrees. \nThe scour protection measure at the site included type-2 stone fill (less than 36 inches \ndiameter) along the base of the left abutment. There was type-1 stone fill (less than 12 \ninches diameter) along the base of the right abutment. There was also type-3 stone fill (less \nthan 48 inches diameter) along both upstream banks at the location of previous bridge \nabutments. 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 modelled flows ranged from 0.1 to 0.4 ft. The worst-case contraction \nscour occurred at the 500-year discharge. Abutment scour ranged from 4.0 to 8.7 ft. The \nworst-case abutment scour occurred at the 100-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/ofr97104","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 (DANVTH00020008) on Town Highway 2, crossing the Morrill Brook, Danville, Vermont: U.S. Geological Survey Open-File Report 97-104, iv, 48 p., https://doi.org/10.3133/ofr97104.","productDescription":"iv, 48 p.","numberOfPages":"53","costCenters":[],"links":[{"id":170105,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97104.PNG"},{"id":279823,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0104/report.pdf"}],"scale":"25000","country":"United States","state":"Vermont","city":"Danville","otherGeospatial":"Morrill 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":"4f4e4b16e4b07f02db6a5654","contributors":{"authors":[{"text":"Ivanoff, Michael A.","contributorId":27105,"corporation":false,"usgs":true,"family":"Ivanoff","given":"Michael","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":240409,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":49984,"text":"ofr97664 - 1997 - Level II scour analysis for Bridge 33 (HUNTTH00220033) on Town Highway 22, crossing Brush Brook, Huntington, Vermont","interactions":[],"lastModifiedDate":"2013-12-17T15:02:59","indexId":"ofr97664","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":"97-664","title":"Level II scour analysis for Bridge 33 (HUNTTH00220033) on Town Highway 22, crossing Brush Brook, Huntington, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nHUNTTH00220033 on Town Highway 22 crossing Brush Brook, Huntington, Vermont \n(figures 1–8). A Level II study is a basic engineering analysis of the site, including a \nquantitative analysis of stream stability and scour (U.S. Department of Transportation, \n1993). Results of a Level I scour investigation also are included in Appendix E of this \nreport. A Level I investigation provides a qualitative geomorphic characterization of the \nstudy site. Information on the bridge, gleaned from Vermont Agency of Transportation \n(VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is \nfound in Appendix D.
\nThe site is in the Green Mountain section of the New England physiographic province in \ncentral Vermont. The 8.65-mi2\n drainage area is in a predominantly rural and forested basin. \nIn the vicinity of the study site, the surface cover is forest except on the downstream right \noverbank which is pasture.
\nIn the study area, Brush Brook has an incised, straight channel with a slope of \napproximately 0.04 ft/ft, an average channel top width of 42 ft and an average bank height \nof 3 ft. The channel bed material ranges from gravel to boulder with a median grain size \n(D50) of 76.7 mm (0.252 ft). The geomorphic assessment at the time of the Level I and \nLevel II site visit on June 26, 1996, indicated that the reach was stable.
\nThe Town Highway 22 crossing of Brush Brook is a 40-ft-long, two-lane bridge consisting \nof one 23.5-foot concrete slab span (Vermont Agency of Transportation, written \ncommunication, November 30, 1995). The opening length of the structure parallel to the \nbridge face is 36.9 ft. The bridge is supported by vertical, concrete abutments with \nwingwalls. The channel is skewed approximately 35 degrees to the opening while the \nopening-skew-to-roadway is 30 degrees.
\nThe scour protection measure at the site was type-2 stone fill (less than 36 inches diameter) \nalong the left and right banks upstream that extended through the bridge and along the \ndownstream banks. Additional details describing conditions at the site are included in the \nLevel 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 analyzed since it has the potential of being the worst-case scour scenario. Total \nscour at a highway crossing is comprised of three components: 1) long-term streambed \ndegradation; 2) contraction scour (due to accelerated flow caused by a reduction in flow \narea at a bridge) and; 3) local scour (caused by accelerated flow around piers and \nabutments). Total scour is the sum of the three components. Equations are available to \ncompute depths for contraction and local scour and a summary of the results of these \ncomputations follows.
\nContraction scour for all modelled flows ranged from 0.0 to 1.1 ft. The worst-case \ncontraction scour occurred at the 500-year discharge. Abutment scour ranged from 6.5 to \n14.9 ft. The worst-case abutment scour occurred at the incipient roadway-overtopping \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/ofr97664","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Burns, R.L., and Degnan, J.R., 1997, Level II scour analysis for Bridge 33 (HUNTTH00220033) on Town Highway 22, crossing Brush Brook, Huntington, Vermont: U.S. Geological Survey Open-File Report 97-664, iv, 51 p., https://doi.org/10.3133/ofr97664.","productDescription":"iv, 51 p.","numberOfPages":"56","costCenters":[],"links":[{"id":176151,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97664.GIF"},{"id":279694,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0664/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\": [ [ [ -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":"4f4e4b19e4b07f02db6a75fa","contributors":{"authors":[{"text":"Burns, Ronda L.","contributorId":71602,"corporation":false,"usgs":true,"family":"Burns","given":"Ronda","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":240584,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Degnan, James R. 0000-0002-5665-9010 jrdegnan@usgs.gov","orcid":"https://orcid.org/0000-0002-5665-9010","contributorId":498,"corporation":false,"usgs":true,"family":"Degnan","given":"James","email":"jrdegnan@usgs.gov","middleInitial":"R.","affiliations":[{"id":405,"text":"NH/VT office of New England Water Science Center","active":true,"usgs":true},{"id":466,"text":"New England Water Science Center","active":true,"usgs":true}],"preferred":true,"id":240583,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49877,"text":"ofr976 - 1997 - Level II scour analysis for Bridge 6 (VICTTH000110006) on Town Highway 1, crossing the Moose River, Victory, Vermont","interactions":[],"lastModifiedDate":"2014-01-07T11:12:39","indexId":"ofr976","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":"97-6","title":"Level II scour analysis for Bridge 6 (VICTTH000110006) on Town Highway 1, crossing the Moose River, Victory, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nVICTTH00010006 on Town Highway 1 crossing the Moose River, Victory, Vermont \n(figures 1–8). A Level II study is a basic engineering analysis of the site, including a \nquantitative analysis of stream stability and scour (U.S. Department of Transportation, \n1993). Results of a Level I scour investigation also are included in Appendix E of this \nreport. A Level I investigation provides a qualitative geomorphic characterization of the \nstudy site. Information on the bridge, gleaned from Vermont Agency of Transportation \n(VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is \nfound in Appendix D.\nThe site is in the White Mountain section of the New England physiographic province in \nnortheastern Vermont. The 27.9-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, the Moose River has an incised, sinuous channel with a slope of \napproximately 0.02 ft/ft, an average channel top width of 108 ft and an average channel \ndepth of 14 ft. The channel bed ranges from gravel to boulder with a median grain size \n(D50) of 126 mm (0.412 ft). The geomorphic assessment at the time of the Level I and Level \nII site visit on July 20, 1995, indicated that the reach was stable.\nThe Town Highway 1 crossing of the Moose River is a 101-ft-long, two-lane bridge \nconsisting of one 98-foot steel-beam span (Vermont Agency of Transportation, written \ncommunication, March 28, 1995). The bridge is supported by vertical, concrete abutments \nwith a spill-through slope at the face of each abutment consisting of type-3 stone fill (less \nthan 48 inches diameter). The channel is skewed approximately 40 degrees to the opening \nwhile the opening-skew-to-roadway is 45 degrees. \nA scour hole 3 ft deeper than the mean thalweg depth was observed under the bridge during \nthe Level I assessment. 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 0.2 to 0.4 ft. The worst-case \ncontraction scour occurred at the 500-year discharge. Abutment scour ranged from 7.3 to \n8.2 ft. The worst-case abutment scour also occurred at the 500-year discharge. Additional \ninformation on scour depths and depths to armoring are included in the section titled “Scour \nResults”. Scoured-streambed elevations, based on the calculated scour depths, are presented \nin tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure \n8. Scour depths were calculated assuming an infinite depth of erosive material and a \nhomogeneous particle-size distribution. \nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr976","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Olson, S.A., 1997, Level II scour analysis for Bridge 6 (VICTTH000110006) on Town Highway 1, crossing the Moose River, Victory, Vermont: U.S. Geological Survey Open-File Report 97-6, iv, 48 p., https://doi.org/10.3133/ofr976.","productDescription":"iv, 48 p.","numberOfPages":"53","costCenters":[],"links":[{"id":169640,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr976.PNG"},{"id":279825,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0006/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Victory","otherGeospatial":"Moose River","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -71.875,44.5 ], [ -71.875,44.625 ], [ -71.75,44.625 ], [ -71.75,44.5 ], [ -71.875,44.5 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b16e4b07f02db6a584d","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":240406,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":49874,"text":"ofr979 - 1997 - Level II scour analysis for Bridge 34 (SHERUS00040034) on U.S. Highway 4, crossing the Ottauquechee River, Sherburne, Vermont","interactions":[],"lastModifiedDate":"2014-01-07T11:02:29","indexId":"ofr979","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":"97-9","title":"Level II scour analysis for Bridge 34 (SHERUS00040034) on U.S. Highway 4, crossing the Ottauquechee River, Sherburne, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nSHERUS00040034 on US Route 4 crossing the Ottauquechee River, Sherburne, Vermont \n(figures 1–8). A Level II study is a basic engineering analysis of the site, including a \nquantitative analysis of stream stability and scour (U.S. Department of Transportation, \n1993). Results of a Level I scour investigation also are included in Appendix E of this \nreport. A Level I investigation provides a qualitative geomorphic characterization of the \nstudy site. Information on the bridge, gleaned from Vermont Agency of Transportation \n(VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is \nfound in Appendix D.\nThe site is in the Green Mountain section of the New England physiographic province in \ncentral Vermont. The 25.8-mi2\n drainage area is in a predominantly rural and forested basin. \nIn the vicinity of the study site, the surface cover is pasture upstream of the bridge while the \nimmediate banks have dense woody vegetation. Downstream of the bridge, the banks are \nforested.\nIn the study area, the Ottauquechee River has an incised, straight channel with a slope of \napproximately 0.028 ft/ft, an average channel top width of 66 ft and an average channel \ndepth of 5 ft. The channel bed material ranges from gravel to boulder with a median grain \nsize (D50) of 118.1 mm (0.387 ft). The geomorphic assessment at the time of the Level I and \nLevel II site visit on September 25, 1995, indicated that the reach was stable.\nThe US Route 4 crossing of the Ottauquechee River is a 187-ft-long, two-lane bridge \nconsisting of three steel-beam spans (Vermont Agency of Transportation, written \ncommunication, March 14, 1995). The bridge is supported by vertical, concrete abutments \nabove spill-through stone fill (< 36 inches diameter). The channel is skewed approximately \n60 degrees to the opening while the opening-skew-to-roadway is 60 degrees. Additional \ndetails describing conditions at the site are included in the Level II Summary and \nAppendices D and E.\nScour depths and rock rip-rap sizes were computed using the general guidelines described \nin Hydraulic Engineering Circular 18 (Richardson and others, 1995). Total scour at a \nhighway crossing is comprised of three components: 1) long-term streambed degradation; \n2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) \nand; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is \nthe sum of the three components. Equations are available to compute depths for contraction \nand local scour and a summary of the results of these computations follows.\nContraction scour for all modelled flows was 0.0 ft. Abutment scour ranged from 4.7 to 7.4 \nft. The worst-case abutment scour occurred at the left abutment for the 500-year discharge. \nPier scour ranged from 7.5 to 11.4 ft. The worst-case pier scour occurred at the incipientovertopping 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/ofr979","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Flynn, R.H., and Severance, T., 1997, Level II scour analysis for Bridge 34 (SHERUS00040034) on U.S. Highway 4, crossing the Ottauquechee River, Sherburne, Vermont: U.S. Geological Survey Open-File Report 97-9, iv, 51 p., https://doi.org/10.3133/ofr979.","productDescription":"iv, 51 p.","numberOfPages":"56","costCenters":[],"links":[{"id":169566,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr979.PNG"},{"id":279827,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0009/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Sherburne","otherGeospatial":"Ottauquechee River","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.875,43.5 ], [ -72.875,43.625 ], [ -72.75,43.625 ], [ -72.75,43.5 ], [ -72.875,43.5 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a6507","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":240401,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Severance, Timothy","contributorId":104927,"corporation":false,"usgs":true,"family":"Severance","given":"Timothy","email":"","affiliations":[],"preferred":false,"id":240402,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49987,"text":"ofr97672 - 1997 - Level II scour analysis for Bridge 21 (MONKTH00340021) on Town Highway 34, crossing Little Otter Creek, Monkton, Vermont","interactions":[],"lastModifiedDate":"2013-12-17T14:42:17","indexId":"ofr97672","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":"97-672","title":"Level II scour analysis for Bridge 21 (MONKTH00340021) on Town Highway 34, crossing Little Otter Creek, Monkton, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nMONKTH00340021 on Town Highway 34 crossing Little Otter Creek, Monkton, 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 D 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 C.
\nThe site is in the Champlain section of the Saint Lawrence Valley physiographic province \nin northwestern Vermont. The 34.1-mi2\n drainage area is in a predominantly rural and \nforested basin with pasture in the valleys. In the vicinity of the study site, the surface cover \nconsists of pasture. The most significant tree cover is immediately adjacent to the channel \non the right bank downstream.
\nIn the study area, Little Otter Creek has a sinuous channel with a slope of approximately \n0.008 ft/ft, an average channel top width of 92 feet and an average bank height of 6 feet. \nThe predominant channel bed materials are silt and clay. Sieve analysis indicates that \ngreater than 50% of the sample is silt and clay and thus a median grain size by use of sieve \nanalysis was indeterminate. Therefore, the median grain size was assumed to be medium \nsilt with a size (D50) of 0.0310 mm (0.000102 ft). The geomorphic assessment at the time of \nthe Level I and Level II site visit on June 19 and June 20, 1996, indicated that the reach was \nstable.
\nThe Town Highway 34 crossing of Little Otter Creek is a 50-ft-long, one-lane bridge \nconsisting of one 26-foot concrete span and three “boiler tube” smooth metal pipe culverts \nthrough the left road approach (Vermont Agency of Transportation, written \ncommunication, December 15, 1995). The opening length of the bridge parallel to the \nbridge face is 25.1 feet. The bridge is supported by vertical, concrete abutments with \nwingwalls on the right abutment only. The channel is skewed approximately 25 degrees to \nthe opening. The VTAOT records indicate the opening-skew-to-roadway is 20 degrees but \nmeasurement from surveyed data suggests the skew is five degrees.
\nThe scour protection measures at the site were type-1 stone fill (less than 12 inches \ndiameter) on the upstream and downstream embankments of the left road approach and \ntype-2 stone fill (less than 36 inches diameter) surrounding the entrance of each culvert. \nAdditional details describing conditions at the site are included in the Level II Summary \nand Appendices C and D.
\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 10.3 to 12.3 feet. The worst-case \ncontraction scour occurred at the 500-year discharge. Abutment scour ranged from 8.6 to \n22.5 feet. The worst-case abutment scour occurred at the 500-year discharge for the left \nabutment and at the incipient overtopping discharge for the right abutment. 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/ofr97672","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Boehmler, E.M., and Medalie, L., 1997, Level II scour analysis for Bridge 21 (MONKTH00340021) on Town Highway 34, crossing Little Otter Creek, Monkton, Vermont: U.S. Geological Survey Open-File Report 97-672, iv, 48 p., https://doi.org/10.3133/ofr97672.","productDescription":"iv, 48 p.","numberOfPages":"53","costCenters":[],"links":[{"id":176248,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97672.GIF"},{"id":279691,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0672/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Monkton","otherGeospatial":"Little Otter Creek","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.75,43.5 ], [ -72.75,43.625 ], [ -72.625,43.625 ], [ -72.625,43.5 ], [ -72.75,43.5 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b1ae4b07f02db6a8126","contributors":{"authors":[{"text":"Boehmler, Erick M.","contributorId":96303,"corporation":false,"usgs":true,"family":"Boehmler","given":"Erick","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":240589,"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":240588,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49873,"text":"ofr971 - 1997 - Level II scour analysis for Bridge 92 (WSTOVT01000092) on State Highway 100, crossing the West River, Weston, Vermont","interactions":[],"lastModifiedDate":"2014-01-07T11:07:07","indexId":"ofr971","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":"97-1","title":"Level II scour analysis for Bridge 92 (WSTOVT01000092) on State Highway 100, crossing the West River, Weston, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nWSTOVT01000092 on Vermont Highway 100 crossing the West River, Weston, 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 32.7-mi2\n drainage area is in a predominantly rural and forested \nbasin. In the vicinity of the study site, the surface cover upstream of the bridge is primarily \nforest with pasture on the upstream left overbank. Upstream and downstream, the \nimmediate banks have brush and dense forest cover. Downstream of the bridge is forested.\nIn the study area, the West River has an incised, sinuous channel with a slope of \napproximately 0.006 ft/ft, an average channel top width of 111 ft and an average channel \ndepth of 3 ft. The predominant channel bed material is very coarse gravel and cobbles with \na median grain size (D50) of 67.7 mm (0.222 ft). The geomorphic assessment at the time of \nthe Level I and Level II site visit on August 19, 1996 indicated that the reach was laterally \nunstable based on the fine bank material, sinuosity of the stream, point bars and cutbanks.\nThe state highway 100 crossing of the West River is a 113-ft-long, two-lane bridge \nconsisting of one 110-foot steel-beam span (Vermont Agency of Transportation, written \ncommunication, March 31, 1995). The bridge is supported by vertical, concrete abutments \nwithout wingwalls. The channel is skewed approximately 40 degrees to the opening while \nthe opening-skew-to-roadway is 25 degrees. \nThe only scour protection measure at the site was type-2 stone fill (less than 36 inches \ndiameter) along the entire base length of the left and right abutments. Additional details \ndescribing conditions at the site are included in the Level II Summary and Appendices D \nand E.\nScour depths and rock rip-rap sizes were computed using the general guidelines described \nin Hydraulic Engineering Circular 18 (Richardson and others, 1995). Total scour at a \nhighway crossing is comprised of three components: 1) long-term streambed degradation; \n2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) \nand; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is \nthe sum of the three components. Equations are available to compute depths for contraction \nand local scour and a summary of the results of these computations follows.\nContraction scour for all modelled flows ranged from 0.4 to 2.1 ft. The worst-case \ncontraction scour occurred at the 500-year discharge. Abutment scour ranged from 8.4 to \n30.7 ft. The worst-case abutment scour occurred at the 500-year discharge along the left \nabutment. Additional information on scour depths and depths to armoring are included in \nthe section titled “Scour Results”. Scoured-streambed elevations, based on the calculated \nscour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the \nbridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of \nerosive material and a homogeneous particle-size distribution. \nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr971","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Flynn, R.H., and Burns, R.L., 1997, Level II scour analysis for Bridge 92 (WSTOVT01000092) on State Highway 100, crossing the West River, Weston, Vermont: U.S. Geological Survey Open-File Report 97-1, iv, 48 p., https://doi.org/10.3133/ofr971.","productDescription":"iv, 48 p.","numberOfPages":"53","costCenters":[],"links":[{"id":169565,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr971.PNG"},{"id":279826,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0001/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Weston","otherGeospatial":"West River","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.875,43.25 ], [ -72.875,43.375 ], [ -72.75,43.375 ], [ -72.75,43.25 ], [ -72.875,43.25 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b16e4b07f02db6a55ce","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":240399,"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":240400,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49989,"text":"ofr97674 - 1997 - Level II scour analysis for Bridge 23 (WALDTH00060023) on Town Highway 6, crossing Stannard Brook, Walden, Vermont","interactions":[],"lastModifiedDate":"2013-12-17T14:06:20","indexId":"ofr97674","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":"97-674","title":"Level II scour analysis for Bridge 23 (WALDTH00060023) on Town Highway 6, crossing Stannard Brook, Walden, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nWALDTH00060023 on Town Highway 6 crossing Stannard Brook, Walden, 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 5.61-mi2\n drainage area is in a predominantly rural and forested \nbasin. In the vicinity of the study site, the upstream surface cover is shrub and brushland \nwith some trees. The downstream surface cover is forest.
\nIn the study area, Stannard Brook has an incised, straight channel with a slope of \napproximately 0.02 ft/ft, an average channel top width of 54 ft and an average bank height \nof 9 ft. The channel bed material ranges from gravel to boulder with a median grain size \n(D50) of 64.0 mm (0.210 ft). The geomorphic assessment at the time of the Level I and \nLevel II site visit on August 8, 1995, indicated that the reach was stable.
\nThe Town Highway 6 crossing of Stannard Brook is a 59-ft-long (bottom width), two-lane \npipe arch culvert consisting of one 22-foot corrugated plate pipe arch span (Vermont \nAgency of Transportation, written communication, March 28, 1995). The opening length of \nthe structure parallel to the bridge face is 21.9 ft.The pipe arch is supported by vertical, \nconcrete kneewalls. The channel is skewed approximately 10 degrees to the opening while \nthe opening-skew-to-roadway is zero degrees.
\nA scour hole 1.5 ft deeper than the mean thalweg depth was observed along the upstream \nend of the right kneewall during the Level I assessment. There was also a scour hole 0.5 ft \ndeeper than the mean thalweg depth observed along the downstream end of the left \nkneewall. The scour counter measures at the site included type-3 stone fill (less than 48 \ninches diameter) at the upstream and downstream end of the left and right kneewall. There \nwas also type-2 stone fill (less than 36 inches diameter) along the upstream right bank. \nAdditional details describing conditions at the site are included in the Level II Summary \nand Appendices D and E.
\nScour depths and recommended rock rip-rap sizes were computed using the general \nguidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995) \nfor the 100- and 500-year discharges. In addition, the incipient roadway-overtopping \ndischarge is determined and analyzed as another potential worst-case scour scenario. Total \nscour at a highway crossing is comprised of three components: 1) long-term streambed \ndegradation; 2) contraction scour (due to accelerated flow caused by a reduction in flow \narea at a bridge) and; 3) local scour (caused by accelerated flow around piers and \nkneewalls). 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 2.3 ft. The worst-case \ncontraction scour occurred at the incipient roadway-overtopping discharge, which was \ngreater than the 100-year discharge. Left kneewall scour ranged from 11.7 to 16.8 ft. The \nworst-case left kneewall scour occurred at the 500-year discharge. Right kneewall scour \nranged from 13.7 to 16.7 ft. The worst-case right kneewall scour occurred at the incipient \nroadway-overtopping discharge. Additional information on scour depths and depths to \narmoring are included in the section titled “Scour Results”. Scoured-streambed elevations, \nbased on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the \nscour computed at the bridge is presented in figure 8. Scour depths were calculated \nassuming an infinite depth of erosive material and a homogeneous particle-size distribution. \nDuring the Level I survey ledge was discovered at the upstream end of the right abutment. \nThe ledge in the channel may limit scour depths.
\nIt is generally accepted that the Froehlich equation (abutment/ kneewall scour) gives \n“excessively conservative estimates of scour depths” (Richardson and others, 1995, p. 47). \nUsually, computed scour depths are evaluated in combination with other information \nincluding (but not limited to) historical performance during flood events, the geomorphic \nstability assessment, existing scour protection measures, and the results of the hydraulic \nanalyses. Therefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr97674","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 23 (WALDTH00060023) on Town Highway 6, crossing Stannard Brook, Walden, Vermont: U.S. Geological Survey Open-File Report 97-674, 50 p., https://doi.org/10.3133/ofr97674.","productDescription":"50 p.","costCenters":[],"links":[{"id":176250,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97674.GIF"},{"id":279689,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0674/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Walden","otherGeospatial":"Stannard Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.375,44.5 ], [ -72.375,44.625 ], [ -72.125,44.625 ], [ -72.125,44.5 ], [ -72.375,44.5 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b1ae4b07f02db6a80c8","contributors":{"authors":[{"text":"Ivanoff, Michael A.","contributorId":27105,"corporation":false,"usgs":true,"family":"Ivanoff","given":"Michael","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":240592,"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":240593,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49991,"text":"ofr97751 - 1997 - Level II scour analysis for Bridge 16 (RIPTTH00110016) on Town Highway 11, crossing the Middle Branch Middlebury River, Ripton, Vermont","interactions":[],"lastModifiedDate":"2013-12-17T13:44:59","indexId":"ofr97751","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":"97-751","title":"Level II scour analysis for Bridge 16 (RIPTTH00110016) on Town Highway 11, crossing the Middle Branch Middlebury River, Ripton, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nRIPTTH00110016 on Town Highway 11 crossing the Middle Branch Middlebury River, \nRipton, 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 \nwest-central Vermont. The 6.6-mi2\n drainage area is in a predominantly rural and forested \nbasin. In the vicinity of the study site, the surface cover consists of shrubs, brush and trees \nexcept for the upstream left bank which is completely forested.
\nIn the study area, the Middle Branch Middlebury River has an incised, sinuous channel with \na slope of approximately 0.03 ft/ft, an average channel top width of 68 ft and an average \nbank height of 5 ft. The channel bed material ranges from gravel to boulder with a median \ngrain size (D50) of 97.6 mm (0.320 ft). The geomorphic assessment at the time of the Level \nI and Level II site visit on June 11, 1996, indicated that the reach was stable.
\nThe Town Highway 11 crossing of the Middle Branch Middlebury River is a 44-ft-long, \ntwo-lane bridge consisting of one 42-foot steel-beam span (Vermont Agency of \nTransportation, written communication, December 15, 1995). The opening length of the \nstructure parallel to the bridge face is 40.2 ft. The bridge is supported by vertical, concrete \nabutments with wingwalls. The channel is skewed approximately 40 degrees to the opening. \nThe opening-skew-to-roadway value from the VTAOT database is 20 degrees while 30 \ndegrees was computed from surveyed points.
\nA scour hole, 3 ft deeper than the mean thalweg depth, was observed along the left \nabutment and upstream left wingwall during the Level I assessment. In addition, 1 ft of \nchannel scour was observed just downstream of the downstream left wingwall along the left \nbank. Scour countermeasures at the site included type-2 stone fill (less than 36 inches \ndiameter) along the upstream left and right banks and along the upstream end of the \ndownstream left wingwall. Additional details describing conditions at the site are included \nin the Level II Summary and Appendices D \nand E.
\nScour depths and 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 0.1 to 0.4 ft. The worst-case \ncontraction scour occurred at the 500-year discharge. Abutment scour ranged from 7.2 to \n8.6 ft along the right abutment and from 11.7 to 13.7 ft along the left abutment. The worstcase abutment scour occurred at the 500-year discharge. Additional information on scour \ndepths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. \nA cross-section of the scour computed at the bridge is presented in figure 8. Scour depths \nwere calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution.
\nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). 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/ofr97751","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Burns, R.L., 1997, Level II scour analysis for Bridge 16 (RIPTTH00110016) on Town Highway 11, crossing the Middle Branch Middlebury River, Ripton, Vermont: U.S. Geological Survey Open-File Report 97-751, iv, 48 p., https://doi.org/10.3133/ofr97751.","productDescription":"iv, 48 p.","numberOfPages":"53","costCenters":[],"links":[{"id":176252,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97751.GIF"},{"id":279687,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0751/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Ripton","otherGeospatial":"Middlebury 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":"4f4e4b1ae4b07f02db6a8286","contributors":{"authors":[{"text":"Burns, Ronda L.","contributorId":71602,"corporation":false,"usgs":true,"family":"Burns","given":"Ronda","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":240596,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":49872,"text":"ofr978 - 1997 - Level II scour analysis for Bridge 7 (WARRTH00010007) onTown Highway 1, crossing Freemans Brook, Warren, Vermont","interactions":[],"lastModifiedDate":"2014-01-07T10:55:12","indexId":"ofr978","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":"97-8","title":"Level II scour analysis for Bridge 7 (WARRTH00010007) onTown Highway 1, crossing Freemans Brook, Warren, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nWARRTH00010007 on Town Highway 1 crossing Freeman Brook, Warren, Vermont \n(figures 1–8). A Level II study is a basic engineering analysis of the site, including a \nquantitative analysis of stream stability and scour (U.S. Department of Transportation, \n1993). Results of a Level I scour investigation also are included in Appendix E of this \nreport. A Level I investigation provides a qualitative geomorphic characterization of the \nstudy site. Information on the bridge, gleaned from Vermont Agency of Transportation \n(VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is \nfound in Appendix D.\nThe site is in the Green Mountain section of the New England physiographic province in \ncentral Vermont. The 6.45-mi2\n drainage area is in a predominantly rural and forested basin. \nIn the vicinity of the study site, the predominant surface cover is grass and trees with the \nexception of the upstream left overbank which is forest. The banks of the channel are tree \ncovered.\nIn the study area, Freeman Brook has an incised, straight channel with a slope of \napproximately 0.03 ft/ft, an average channel top width of 51 ft and an average channel \ndepth of 6 ft. The predominant channel bed material ranges from gravel to bedrock with a \nmedian grain size (D50) of 86.8 mm (0.285 ft). The geomorphic assessment at the time of \nthe Level I and Level II site visit on July 22, 1996 indicated that the reach was stable.\nThe Town Highway 1 crossing of Freeman Brook is a 64-ft-long, two-lane bridge \nconsisting of one 62-foot steel-beam span (Vermont Agency of Transportation, written \ncommunication, February 1, 1996). The bridge is supported by vertical, concrete abutments \nwith spill-through slopes. The channel is skewed approximately 25 degrees to the opening \nwhile the opening-skew-to-roadway is 30 degrees. \nThe only scour protection measure at the site was type-2 stone fill (less than 36 inches \ndiameter) along the entire length of the left and right abutments and along the downstream \nchannel banks. Additional details describing conditions at the site are included in the Level \nII 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.\nThe computed contraction scour for all modelled flows was 0.0 feet. Abutment scour \nranged from 5.3 to 8.2 ft. The worst-case abutment scour occurred at the right abutment for \nthe incipient-overtopping discharge. Additional information on scour depths and depths to \narmoring are included in the section titled “Scour Results”. Scoured streambed elevations, \nbased on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the \nscour computed at the bridge is presented in figure 8. Scour depths were calculated \nassuming an infinite depth of erosive material and a homogeneous particle-size distribution. \nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr978","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Flynn, R.H., and Burns, R.L., 1997, Level II scour analysis for Bridge 7 (WARRTH00010007) onTown Highway 1, crossing Freemans Brook, Warren, Vermont: U.S. Geological Survey Open-File Report 97-8, iv, 52 p., https://doi.org/10.3133/ofr978.","productDescription":"iv, 52 p.","numberOfPages":"57","costCenters":[],"links":[{"id":169564,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr978.PNG"},{"id":279828,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0008/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Warren","otherGeospatial":"Freeman Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.875,44.0 ], [ -72.875,44.125 ], [ -72.75,44.125 ], [ -72.75,44.0 ], [ -72.875,44.0 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b16e4b07f02db6a5728","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":240397,"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":240398,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49992,"text":"ofr97752 - 1997 - Level II scour analysis for Bridge 17 (LYNDTH00020017) on Town Highway 2, crossing Hawkins Brook, Lyndon, Vermont","interactions":[],"lastModifiedDate":"2016-08-25T15:34:25","indexId":"ofr97752","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":"97-752","title":"Level II scour analysis for Bridge 17 (LYNDTH00020017) on Town Highway 2, crossing Hawkins Brook, Lyndon, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure LYNDTH00020017 on Town Highway 2 crossing Hawkins Brook, Lyndon, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including a quantitative analysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of a Level I scour investigation also are included in Appendix E of this report. A Level I investigation provides a qualitative geomorphic characterization of the study site. Information on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is found in Appendix D.
The site is in the Green Mountain section of the New England physiographic province in northeastern Vermont. The 7.7-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is forest on the left and right upstream overbanks. The downstream left and right overbanks are brushland.
In the study area, Hawkins Brook has an incised, sinuous channel with a slope of approximately 0.02 ft/ft, an average channel top width of 78 ft and an average bank height of 7.3 ft. The channel bed material ranges from sand to boulder with a median grain size (D50) of 46.6 mm (0.153 ft). The geomorphic assessment at the time of the Level I and Level II site visit on August 4, 1995, indicated that the reach was laterally unstable with the presence of point bars and side bars.
The Town Highway 2 crossing of Hawkins Brook is a 49-ft-long, two-lane bridge consisting of a 46-foot steel-stringer span (Vermont Agency of Transportation, written communication, March 27, 1995). The opening length of the structure parallel to the bridge face is 43 ft. The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 45 degrees to the opening while the computed opening-skew-to-roadway is zero degrees.
A scour hole 0.75 ft deeper than the mean thalweg depth was observed along the downstream left abutment during the Level I assessment. The only scour protection measure at the site was type-2 stone fill (less than 36 inches diameter) at the upstream end of the downstream left wingwall. Additional details describing conditions at the site are included in the Level II Summary and Appendices D and E.
Scour depths and recommended rock rip-rap sizes were computed using the general guidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995) for the 100- and 500-year discharges. Total scour at a highway crossing is comprised of three components: 1) long-term streambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is the sum of the three components. Equations are available to compute depths for contraction and local scour and a summary of the results of these computations follows.
Contraction scour for all modelled flows ranged from 0.1 to 0.9 ft. The worst-case contraction scour occurred at the 500-year discharge. Abutment scour ranged from 3.8 to 6.6 ft. The worst-case abutment scour occurred at the 500-year discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution.
It is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, computed scour depths are evaluated in combination with other information including (but not limited to) historical performance during flood events, the geomorphic stability assessment, existing scour protection measures, and the results of the hydraulic analyses. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr97752","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Wild, E.C., and Medalie, L., 1997, Level II scour analysis for Bridge 17 (LYNDTH00020017) on Town Highway 2, crossing Hawkins Brook, Lyndon, Vermont: U.S. Geological Survey Open-File Report 97-752, iv, 48 p., https://doi.org/10.3133/ofr97752.","productDescription":"iv, 48 p.","numberOfPages":"53","costCenters":[],"links":[{"id":176839,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97752.GIF"},{"id":279686,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0752/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Lyndon","otherGeospatial":"Hawkins 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":"4f4e4b1ae4b07f02db6a8265","contributors":{"authors":[{"text":"Wild, Emily C. 0000-0001-6157-7629 ecwild@usgs.gov","orcid":"https://orcid.org/0000-0001-6157-7629","contributorId":1810,"corporation":false,"usgs":true,"family":"Wild","given":"Emily","email":"ecwild@usgs.gov","middleInitial":"C.","affiliations":[{"id":5081,"text":"Libraries","active":false,"usgs":true}],"preferred":false,"id":240597,"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":240598,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49871,"text":"ofr977 - 1997 - Level II scour analysis for Bridge 144 (ROCHVT01000144) on State Route 100, crossing the White River, Rochester, Vermont","interactions":[],"lastModifiedDate":"2016-08-25T12:37:23","indexId":"ofr977","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":"97-7","title":"Level II scour analysis for Bridge 144 (ROCHVT01000144) on State Route 100, crossing the White River, Rochester, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure ROCHVT01000144 on State Route 100 crossing the White River, Rochester, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including a quantitative analysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of a Level I scour investigation also are included in Appendix E of this report. A Level I investigation provides a qualitative geomorphic characterization of the study site. Information on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is found in Appendix D.
The site is in the Green Mountain section of the New England physiographic province in central Vermont. The 68.9-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is pasture with forest on the valley walls.
In the study area, the White River has a meandering channel with a slope of approximately 0.003 ft/ft, an average channel top width of 119 ft and an average channel depth of 4 ft. The predominant channel bed material is gravel and cobbles with a median grain size (D50) of 72.5 mm (0.238 ft). The geomorphic assessment at the time of the Level I and Level II site visit on July 22, 1996, indicated that the reach was laterally unstable due to a cut-bank present on the upstream left bank and wide point bars upstream and downstream in the vicinity of this site.
The State Route 100 crossing of the White Riveris a 103-ft-long, two-lane bridge consisting of one 101-foot steel-beam span (Vermont Agency of Transportation, written communication, March 8, 1995). The bridge is supported by vertical, concrete abutment walls with spill-through embankments in front of each abutment wall and no wingwalls. The channel is skewed approximately 10 degrees to the opening while the opening-skew-toroadway is 5 degrees.
The scour protection measures at the site are type-2 stone fill (less than 36 inches diameter) on the upstream left bank, both abutment spill-through embankments, and the downstream banks. There also is type-1 stone fill (less than 12 inches diameter) on the upstream right bank. The stone fill is continuous on both sides of the river in the vicinity of the bridge. Additional details describing conditions at the site are included in the Level II Summary and Appendices D and E.
Scour depths and rock rip-rap sizes were computed using the general guidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 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.
There was no computed contraction scour for the modelled flows. Abutment scour ranged from 6.9 to 10.9 ft. The worst-case abutment scour occurred at the incipient overtopping discharge, which was less than the 100-year discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particlesize distribution.
It is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, computed scour depths are evaluated in combination with other information including (but not limited to) historical performance during flood events, the geomorphic stability assessment, existing scour protection measures, and the results of the hydraulic analyses. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr977","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Boehmler, E.M., and Wild, E.C., 1997, Level II scour analysis for Bridge 144 (ROCHVT01000144) on State Route 100, crossing the White River, Rochester, Vermont: U.S. Geological Survey Open-File Report 97-7, iv, 50 p., https://doi.org/10.3133/ofr977.","productDescription":"iv, 50 p.","numberOfPages":"55","costCenters":[],"links":[{"id":169563,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr977.PNG"},{"id":279829,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0007/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Rochester","otherGeospatial":"White River","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.875,43.875 ], [ -72.875,44.0 ], [ -72.75,44.0 ], [ -72.75,43.875 ], [ -72.875,43.875 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b1ae4b07f02db6a82e1","contributors":{"authors":[{"text":"Boehmler, Erick M.","contributorId":96303,"corporation":false,"usgs":true,"family":"Boehmler","given":"Erick","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":240396,"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":240395,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49870,"text":"ofr973 - 1997 - Level II scour analysis for Bridge 120 (LEICUS00070120) on U.S. Route 7, crossing the Leicester River, Leicester, Vermont","interactions":[],"lastModifiedDate":"2014-01-07T10:41:22","indexId":"ofr973","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":"97-3","title":"Level II scour analysis for Bridge 120 (LEICUS00070120) on U.S. Route 7, crossing the Leicester River, Leicester, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nLEICUS00070120 on U. S. Route 7 crossing the Leicester River, Leicester, Vermont \n(figures 1–8). A Level II study is a basic engineering analysis of the site, including a \nquantitative analysis of stream stability and scour (U.S. Department of Transportation, \n1993). Results of a Level I scour investigation also are included in Appendix E of this \nreport. A Level I investigation provides a qualitative geomorphic characterization of the \nstudy site. Information on the bridge, gleaned from Vermont Agency of Transportation \n(VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is \nfound in Appendix D.\nThe site is in the Green Mountain section of the New England physiographic province in \nwest-central Vermont. The 23.0-mi2\n drainage area is in a predominantly rural and forested\nbasin. In the vicinity of the study site, the surface cover consists of shrubs, brush, and \npasture with some trees except for the upstream left overbank area which is forest.\nIn the study area, the Leicester River has a sinuous channel with a slope of approximately \n0.002 ft/ft, an average channel top width of 52 ft and an average channel depth of 3 ft. The \npredominant channel bed material is sand and gravel with a median grain size (D50) of 3.10 \nmm (0.0102 ft). The geomorphic assessment at the time of the Level I and Level II site visit \non September 18, 1995, indicated that the reach was laterally unstable. Lateral instability \nwas evident with the presence of some bank material failure and fallen or leaning vegetation \nat cut-banks upstream and downstream of this site. Point bars also were found near this site.\nThe U. S. Route 7 crossing of the Leicester Riveris a 108-ft-long, two-lane bridge \nconsisting of two 52-foot steel-beam spans (Vermont Agency of Transportation, written \ncommunication, March 13, 1995). The bridge is supported by vertical, concrete abutment \nwalls with stone fill spill-through embankments on each abutment and one pier. The \nchannel is skewed approximately 30 degrees to the opening while the opening-skew-toroadway is 15 degrees.\nThe only scour protection measure at the site was type-3 stone fill (less than 48 inches \ndiameter) on the spill-through embankments of each abutment. 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 3.8 to 6.1 ft. The worst-case \ncontraction scour occurred at the 500-year discharge. Abutment scour ranged from 4.0 to \n6.7 ft. The worst-case abutment scour also occurred at the 500-year discharge. Pier scour \nranged from 9.1 to 10.2. The worst-case pier scour occurred at the 500-year discharge. \nAdditional information on scour depths and depths to armoring are included in the section \ntitled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, \nare presented in tables 1 and 2. A cross-section of the scour computed at the bridge is \npresented in figure 8. Scour depths were calculated assuming an infinite depth of erosive \nmaterial and a homogeneous particle-size distribution. \nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr973","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Boehmler, E.M., and Severance, T., 1997, Level II scour analysis for Bridge 120 (LEICUS00070120) on U.S. Route 7, crossing the Leicester River, Leicester, Vermont: U.S. Geological Survey Open-File Report 97-3, iv, 49 p., https://doi.org/10.3133/ofr973.","productDescription":"iv, 49 p.","numberOfPages":"54","costCenters":[],"links":[{"id":169562,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr973.PNG"},{"id":279830,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0003/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Leicester","otherGeospatial":"Leicester River","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -73.125,43.875 ], [ -73.125,44.0 ], [ -73.0,44.0 ], [ -73.0,43.875 ], [ -73.125,43.875 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b1ae4b07f02db6a83ba","contributors":{"authors":[{"text":"Boehmler, Erick M.","contributorId":96303,"corporation":false,"usgs":true,"family":"Boehmler","given":"Erick","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":240393,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Severance, Timothy","contributorId":104927,"corporation":false,"usgs":true,"family":"Severance","given":"Timothy","email":"","affiliations":[],"preferred":false,"id":240394,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ]}