This study investigated the Taylor coal bed in Johnson and Martin counties, eastern Kentucky, using field and petrographic techniques to develop a depositional model of the coal bed. Petrography and chemistry of the coal bed were examined. Multiple benches of the Taylor coal bed were correlated over a 10 km distance. Three sites were studied in detail. The coal at the western and eastern sites were relatively thin and split by thick clastic partings. The coal at the central site was the thickest and unsplit. Two major clastic partings are included in the coal bed. Each represents a separate and distinct fluvial splay.
The Taylor is interpreted to have developed on a coastal plain with periodic flooding from nearby, structurally-controlled fluvial systems. Doming is unlikely due to the petrographic and chemical trends, which are inconsistent with modern Indonesian models. The depositional history and structural and stratigraphic setting suggest contemporaneous structural influence on thickness and quality of the Taylor coal bed in this area.
Concentrations of tourmaline in Early Proterozoic metasedimentary rocks of the Cuyuna iron range, east-central Minnesota, provide a basis for redefinition of the evolutionary history of the area. Manganiferous iron ore forms beds within the Early Proterozoic Trommald Formation, between thick-bedded granular iron-formation having shallow-water alepositional attributes and thin-bedded, nongranular iron-formation having deeper water attributes. These manganese-rich units were previously assumed to be sedimentary in origin. However, a reevaluation of drill core and mine samples from the Cuyuna North range has identified strata-bound tourmaline and tourmalinite, which has led to a rethinking of genetic models for the geology of the North range. We interpret the tourmaline-rich rocks of the area to be a product of submarine-hydrothermal solutions flowing along and beneath the sediment-seawater interface. This model for the depositional environment of the tourmaline is supported by previously reported mineral assemblages within the Trommald Formation that comprise aegirine; barium feldspar; manganese silicates, carbonates, and oxides; and Sr-rich barite veins.In many places, tourmaline-rich metasedimentary rocks and tourmalinites are associated locally with strata-bound sulfide deposits. At those localities, the tourmaline-rich strata are thought to be lateral equivalents of exhalative sulfide zones or genetically related subsea-floor replacements. On the basis of the occurrence of the tourmaline-rich rocks and tourmalinites, and on the associated minerals, we suggest that there is a previously unrecognized potential for sediment-hosted sulfide deposits in the Cuyuna North range.
","language":"English","publisher":"Society of Economic Geologists","doi":"10.2113/gsecongeo.91.7.1282","issn":"03610128","usgsCitation":"Cleland, J., Morey, G.B., and McSwiggen, P., 1996, Significance of tourmaline-rich rocks in the North Range group of the Cuyuna iron range, east-central Minnesota: Economic Geology, v. 91, no. 7, p. 1282-1291, https://doi.org/10.2113/gsecongeo.91.7.1282.","productDescription":"10 p.","startPage":"1282","endPage":"1291","numberOfPages":"10","costCenters":[],"links":[{"id":228876,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"91","issue":"7","noUsgsAuthors":false,"publicationDate":"1996-11-01","publicationStatus":"PW","scienceBaseUri":"505b8f21e4b08c986b318d43","contributors":{"authors":[{"text":"Cleland, J.M.","contributorId":100559,"corporation":false,"usgs":true,"family":"Cleland","given":"J.M.","email":"","affiliations":[],"preferred":false,"id":378322,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Morey, G. B.","contributorId":14406,"corporation":false,"usgs":true,"family":"Morey","given":"G.","email":"","middleInitial":"B.","affiliations":[],"preferred":false,"id":378320,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"McSwiggen, P.L.","contributorId":61970,"corporation":false,"usgs":true,"family":"McSwiggen","given":"P.L.","email":"","affiliations":[],"preferred":false,"id":378321,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70164310,"text":"70164310 - 1996 - Mortality estimates of striped bass caught in Albemarle Sound and Roanoke River, North Carolina","interactions":[],"lastModifiedDate":"2016-02-01T10:13:56","indexId":"70164310","displayToPublicDate":"1995-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2886,"text":"North American Journal of Fisheries Management","active":true,"publicationSubtype":{"id":10}},"title":"Mortality estimates of striped bass caught in Albemarle Sound and Roanoke River, North Carolina","docAbstract":"A statistical analysis of the age composition of striped bass Morone saxatilis harvested in Albemarle Sound and the Roanoke River, North Carolina. indicated that in 1988–1992 the population experienced a relatively high rate of total mortality. Age-3 and older fish were estimated to have been fully vulnerable to fishing mortality and to have experienced a total instantaneous mortality rate of 1.04/year, which equals about 65% annually. Legal size limits in directed striped bass fisheries appear to have provided some protection to age-2 fish, which were only partially vulnerable to fishing mortality. The portion of total mortality due to fishing could not be estimated unconditionally because the numbers of striped bass taken in fisheries not directed at striped bass were unknown. An eggs-per-recruit model was developed to provide a conceptual framework for comparing the effects of fishery management options, such as reductions in hycatch or fishing mortality. on the striped bass population.
","language":"English","publisher":"Taylor & Francis","doi":"10.1577/1548-8675(1995)015<0290:MEOSBC>2.3.CO;2","usgsCitation":"Dorazio, R.M., 1996, Mortality estimates of striped bass caught in Albemarle Sound and Roanoke River, North Carolina: North American Journal of Fisheries Management, v. 15, no. 2, p. 290-299, https://doi.org/10.1577/1548-8675(1995)015<0290:MEOSBC>2.3.CO;2.","productDescription":"10 p.","startPage":"290","endPage":"299","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[{"id":566,"text":"Southeast Ecological Science Center","active":true,"usgs":true}],"links":[{"id":316362,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"15","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"56b08fe1e4b010e2af2a5de7","contributors":{"authors":[{"text":"Dorazio, Robert M. 0000-0003-2663-0468 bob_dorazio@usgs.gov","orcid":"https://orcid.org/0000-0003-2663-0468","contributorId":1668,"corporation":false,"usgs":true,"family":"Dorazio","given":"Robert","email":"bob_dorazio@usgs.gov","middleInitial":"M.","affiliations":[{"id":566,"text":"Southeast Ecological Science Center","active":true,"usgs":true}],"preferred":false,"id":596939,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":49830,"text":"ofr96564 - 1996 - Level II scour analysis for Bridge 15 (GRNVTH00230015) on Town Highway 23, crossing the Third Branch of the White River, Granville, Vermont","interactions":[],"lastModifiedDate":"2013-12-05T15:46:25","indexId":"ofr96564","displayToPublicDate":"1994-01-01T07:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"96-564","title":"Level II scour analysis for Bridge 15 (GRNVTH00230015) on Town Highway 23, crossing the Third Branch of the White River, Granville, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure GRNVTH00230015 on town highway 23 crossing the Third Branch of the White River, Granville, 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). A Level I study is included in Appendix E of this report. A Level I study provides a qualitative geomorphic characterization of the study site. Information on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II analyses and can be found in Appendix D.\nThe site is in the Green Mountain physiographic province of central Vermont in the town of Granville. The 23.6-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the banks have woody vegetation coverage except for the downstream banks, which are residential.\nIn the study area, the Third Branch of the White River has an incised, sinuous channel with a slope of approximately 0.0128 ft/ft, an average channel top width of 42 ft and an average channel depth of 4 ft. The predominant channel bed material is cobble (D50 is 108 mm or 0.353 ft). The geomorphic assessment at the time of the Level I and Level II site visit on October 21, 1994, indicated that the reach was laterally unstable.\nThe town highway 23 crossing of the Third Branch of the White River is a 35-ft-long, one-lane bridge consisting of one 31-foot steel beam span (Vermont Agency of Transportation, written communication, August 26, 1994). The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 10 degrees to the opening while the opening-skew-to-roadway is 10 degrees.
\nThe only scour protection measures in place at the site were type-1 stone fill (less than 12 inches diameter) along the upstream right bank, upstream right wingwall, and right abutment. Retaining walls are in place along the upstream left bank up to the upstream end of the upstream left wingwall and both downstream banks with the left bank wall extending from the downstream left wingwall. 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).\nTotal 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 scour 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 to 0.4 ft. The worst-case contraction scour occurred at the incipient overtopping discharge. Abutment scour ranged from 9.8 to 13.9 ft. The worst-case abutment scour occurred at 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 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","doi":"10.3133/ofr96564","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Ivanoff, M.A., and Olson, S.A., 1996, Level II scour analysis for Bridge 15 (GRNVTH00230015) on Town Highway 23, crossing the Third Branch of the White River, Granville, Vermont: U.S. Geological Survey Open-File Report 96-564, iv, 50 p., https://doi.org/10.3133/ofr96564.","productDescription":"iv, 50 p.","numberOfPages":"54","costCenters":[],"links":[{"id":161887,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96564.GIF"},{"id":279335,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0564/report.pdf"}],"country":"United States","state":"Vermont","city":"Granville","otherGeospatial":"White River","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.85792,43.98145 ], [ -72.85792,43.988629 ], [ -72.845249,43.988629 ], [ -72.845249,43.98145 ], [ -72.85792,43.98145 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b1ae4b07f02db6a82cc","contributors":{"authors":[{"text":"Ivanoff, Michael A.","contributorId":27105,"corporation":false,"usgs":true,"family":"Ivanoff","given":"Michael","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":240334,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Olson, Scott A. 0000-0002-1064-2125 solson@usgs.gov","orcid":"https://orcid.org/0000-0002-1064-2125","contributorId":2059,"corporation":false,"usgs":true,"family":"Olson","given":"Scott","email":"solson@usgs.gov","middleInitial":"A.","affiliations":[{"id":405,"text":"NH/VT office of New England Water Science Center","active":true,"usgs":true}],"preferred":true,"id":240333,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49867,"text":"ofr96238 - 1996 - Level II scour analysis for Bridge 24 (WODSTH00190024) on Town Highway 19, crossing North Bridgewater Brook, Woodstock, Vermont","interactions":[],"lastModifiedDate":"2013-12-20T15:09:31","indexId":"ofr96238","displayToPublicDate":"1994-01-01T07:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"96-238","title":"Level II scour analysis for Bridge 24 (WODSTH00190024) on Town Highway 19, crossing North Bridgewater Brook, Woodstock, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nWODSTH00190024 on Town Highway 19 crossing North Bridgewater Brook, Woodstock, \nVermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including \na quantitative analysis of stream stability and scour (U.S. Department of Transportation, \n1993). A Level I study is included in Appendix E of this report. A Level I study provides \na qualitative geomorphic characterization of the study site. Information on the bridge \navailable from VTAOT files was compiled prior to conducting Level I and Level II \nanalyses and can be found in Appendix D.\nThe site is in the Green Mountain physiographic province of east-central Vermont in the \ntown of Woodstock. The 3.6-mi2\n drainage area is in a predominantly rural and forested\nbasin. In the vicinity of the study site, the left and right banks are covered by moderate tree \ncover along the immediate banks with some pasture/ grassland beyond.\nIn the study area, the North Bridgewater Brook has a sinuous channel with a slope of \napproximately 0.03 ft/ft, an average channel top width of 44 ft and an average channel \ndepth of 4 ft. The channel bed materials ranges from sand to boulders with a D50 (median \ndiameter)of 70.1 mm or 0.229 ft. The geomorphic assessment at the time of the Level I and \nLevel II site visits on August 17, 1994 and December 13, 1994, indicated that the reach was \nstable. Localized bank cutting existed at the immediate downstream left bank.\nThe Town Highway 19 crossing of the North Bridgewater Brook is a 26-ft-long, one-lane\nbridge consisting of one 23-ft steel-beam span (Vermont Agency of Transportation, written \ncommun., August 3, 1994). The bridge is supported by vertical, concrete abutments with \nwingwalls. Type-2 (less than 3 ft diameter) stone fill protects the upstream left wingwall \nwhich is impacted by flow. The channel bed under the bridge is constructed of wood. This \nconstruction is preventing channel degradation along the impacted left abutment.The \nchannel is skewed approximately 40 degrees to the opening; the opening-skew-to-roadway \nis 10 degrees. Additional details describing conditions at the site are included in the Level II \nSummary and Appendices D and E.\nScour depths and rock rip-rap sizes were computed using the general guidelines described \nin Hydraulic Engineering Circular 18 (Richardson and others, 1993). Total scour at a \nhighway crossing is comprised of three components: 1) long-term streambed degradation; \n2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) \nand; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is \nthe sum of the three components. Equations are available to compute depths for contraction \nand local scour and a summary of the results of these computations follows.\nContraction scour for all modelled flows ranged from 0.0 to 0.8 ft. Abutment scour ranged \nfrom 6.6 to 14.9 ft. with the worst-case scenario occurring 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. \n It is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1993, p. 48). Many factors, \nincluding historical performance during flood events, the geomorphic assessment, scour \nprotection measures, and the results of the hydraulic analyses, must be considered to \nproperly assess the validity of abutment scour results. Therefore, scour depths adopted by \nVTAOT may differ from the computed values documented herein, based on the \nconsideration of additional contributing factors and experienced engineering judgement.","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr96238","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Olson, S.A., and Song, D.L., 1996, Level II scour analysis for Bridge 24 (WODSTH00190024) on Town Highway 19, crossing North Bridgewater Brook, Woodstock, Vermont: U.S. Geological Survey Open-File Report 96-238, iv, 53 p., https://doi.org/10.3133/ofr96238.","productDescription":"iv, 53 p.","numberOfPages":"57","costCenters":[],"links":[{"id":169496,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96238.PNG"},{"id":279834,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0238/report.pdf"}],"country":"United States","state":"Vermont","city":"Woodstock","otherGeospatial":"North Bridgewater Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.577893,43.646059 ], [ -72.577893,43.648843 ], [ -72.557282,43.648843 ], [ -72.557282,43.646059 ], [ -72.577893,43.646059 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b1ae4b07f02db6a8091","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":240387,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Song, Donald L.","contributorId":107335,"corporation":false,"usgs":true,"family":"Song","given":"Donald","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":240388,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49866,"text":"ofr96235 - 1996 - Level II scour analysis for Bridge 8 (HANCTH00020008) on Town Highway 2, crossing Hancock Branch White River, Hancock, Vermont","interactions":[],"lastModifiedDate":"2013-12-20T15:20:47","indexId":"ofr96235","displayToPublicDate":"1994-01-01T07:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"96-235","title":"Level II scour analysis for Bridge 8 (HANCTH00020008) on Town Highway 2, crossing Hancock Branch White River, Hancock, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nHANCTH00020008 on town highway 2 crossing the Hancock Branch White River, \nHancock, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, \nincluding a quantitative analysis of stream stability and scour (U.S. Department of \nTransportation, 1993). A Level I study is included in Appendix E of this report. A Level I \nstudy provides a qualitative geomorphic characterization of the study site. Information on \nthe bridge, gleaned from VTAOT files, was compiled prior to conducting Level I and Level \nII analyses and can be found in Appendix D.\nThe site is in the Green Mountain physiographic province of central Vermont in the town of \nHancock. The 8.4-mi2\n drainage area is predominantly rural and forested. In the vicinity of \nthis site, the banks have dense woody vegetation coverage.\nIn the study area, the Hancock Branch White River is an incised, sinuous channel with a \nslope of approximately 0.038 ft/ft, an average channel top width of 47.0 ft and an average \nchannel depth of 3.0 ft. The predominant channel bed material is cobble (D50\n is 102 mm or \n0.336 ft). The geomorphic assessment at the time of the Level I and Level II site visit on \nNovember 16, 1994, indicated that the reach was stable.\nThe town highway 2 crossing of the Hancock Branch White Riveris a 33-ft-long, two-lane\nbridge consisting of one 30-foot steel-beam span with a concrete deck (Vermont Agency of \nTransportation, written commun., August 26, 1994). The bridge is supported by steep \nsloping, cement-grouted, cobble-stone abutments with wingwalls. The channel is skewed \napproximately ten degrees to the opening while the opening-skew-to-roadway is zero \ndegrees. \nA scour hole 1.5 ft deeper than the mean thalweg depth was observed along the upstream \nleft wingwall and left abutment during the Level I assessment. The only scour protection \nmeasure at the site was type-2 stone fill (less than 36 inches diameter) at the upstream end \nof the upstream left wingwall. Additional details describing conditions at the site are \nincluded in the Level II Summary and Appendices D and E.\nScour depths and rock rip-rap sizes were computed using the general guidelines described \nin Hydraulic Engineering Circular 18 (Richardson and others, 1993).\nTotal scour at a highway crossing is comprised of three components: 1) long-term \naggradation or degradation; 2) contraction scour (due to reduction in flow area caused by a \nbridge) and; 3) local scour (caused by accelerated flow around piers and abutments). Total \nscour is the sum of the three components. Equations are available to compute scour depths \nfor contraction and local scour and a summary of the results follows.\nContraction scour for all modelled flows ranged from 0.6 ft to 1.3 ft and the worst-case \ncontraction scour occurred at the 500-year discharge. Abutment scour ranged from 9.4 ft to \n15.2 ft and the worst-case abutment scour occurred at the 500-year discharge. Scour depths \nand depths to armoring are summarized on p. 14 in the section titled “Scour Results”. \nScour elevations, based on the calculated depths are presented in tables 1 and 2; a graph of \nthe scour elevations is presented in figure 8 Scour depths were calculated assuming an \ninfinite depth of erosive material and a homogeneous particle-size distribution. \nFor all scour presented in this report, “the scour depths adopted [by VTAOT] may differ \nfrom the equation values based on engineering judgement” (Richardson and others, 1993, p. \n21, 27). It is generally accepted that the Froehlich equation (abutment scour) gives \n“excessively conservative estimates of scour depths” (Richardson and others, 1993, p. 48). \nMany factors, including historical performance during flood events, the geomorphic \nassessment, and the results of the hydraulic analyses, must be considered to properly assess \nthe validity of abutment scour results.","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr96235","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Boehmler, E.M., 1996, Level II scour analysis for Bridge 8 (HANCTH00020008) on Town Highway 2, crossing Hancock Branch White River, Hancock, Vermont: U.S. Geological Survey Open-File Report 96-235, iv, 50 p., https://doi.org/10.3133/ofr96235.","productDescription":"iv, 50 p.","numberOfPages":"54","costCenters":[],"links":[{"id":169495,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96235.PNG"},{"id":279833,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0235/report.pdf"}],"country":"United States","state":"Vermont","city":"Hancock","otherGeospatial":"Hancock Branch White River","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -73.001639,43.861648 ], [ -73.001639,43.975114 ], [ -72.81633,43.975114 ], [ -72.81633,43.861648 ], [ -73.001639,43.861648 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b16e4b07f02db6a565f","contributors":{"authors":[{"text":"Boehmler, Erick M.","contributorId":96303,"corporation":false,"usgs":true,"family":"Boehmler","given":"Erick","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":240386,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":49829,"text":"ofr96563 - 1996 - Level II scour analysis for Bridge 35 (RANDTH00650035) on Town Highway 65, crossing the Second Branch White River, Randolph, Vermont","interactions":[],"lastModifiedDate":"2013-12-06T11:14:17","indexId":"ofr96563","displayToPublicDate":"1994-01-01T07:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"96-563","title":"Level II scour analysis for Bridge 35 (RANDTH00650035) on Town Highway 65, crossing the Second Branch White River, Randolph, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure RANDTH00650035 on town highway 65 crossing the Second Branch White River, Randolph, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including a quantitative analysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of a Level I scour investigation also are included in Appendix E of this report. A Level I investigation provides a qualitative geomorphic characterization of the study site. Information on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is found in Appendix D.\nThe site is in the Green Mountain section of the New England physiographic province of central Vermont. The 47.2-mi2 drainage area is in a predominantly rural basin. In the vicinity of the study site, the surface cover is pasture except for the downstream left bank which is forested. There is some woody vegetation on the immediate channel banks upstream of the bridge.
\nIn the study area, the Second Branch White River has a sinuous channel with alluvial boundaries and a slope of approximately 0.002 ft/ft, an average channel top width of 52 ft and an average channel depth of 7 ft. The predominant channel bed materials are sand and gravel with a median grain size (D50) of 1.37 mm (0.0045 ft). The geomorphic assessment at the time of the Level I site visits on August 11, 1994 and December 1, 1994, indicated that the reach was laterally unstable.
\nThe town highway 65 crossing of the Second Branch White River is a 33-ft-long, one-lane bridge consisting of one 28-foot steel-beam span (Vermont Agency of Transportation, written communication, July 29, 1994). The bridge is supported by vertical, stone abutments with wingwalls. The channel is skewed approximately 25 degrees to the opening while the opening-skew-to-roadway is 15 degrees. Additional details describing conditions at the site are included in the Level II Summary and Appendices D and E.
\nScour depths and rock rip-rap sizes were computed using the general guidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995). Total scour at a highway crossing is comprised of three components: 1) long-term streambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is the sum of the three components. Equations are available to compute depths for contraction and local scour and a summary of the results of these computations follows.
\nContraction scour for all modelled flows ranged from 0.0 to 2.4 ft. The worst-case contraction scour occurred at the incipient-overtopping discharge which was\n5,870 cfs less than the 100-year discharge. Abutment scour at the left abutment ranged from 5.7 to 13.9 ft. with the worst-case occurring at the 500-year discharge. Abutment scour at the right abutment ranged from 9.2 to 11.3 ft. with the worst-case occurring 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.\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","doi":"10.3133/ofr96563","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Olson, S.A., 1996, Level II scour analysis for Bridge 35 (RANDTH00650035) on Town Highway 65, crossing the Second Branch White River, Randolph, Vermont: U.S. Geological Survey Open-File Report 96-563, iv, 51 p., https://doi.org/10.3133/ofr96563.","productDescription":"iv, 51 p.","numberOfPages":"55","costCenters":[],"links":[{"id":179261,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96563.GIF"},{"id":279336,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0563/report.pdf"}],"country":"United States","state":"Vermont","city":"Randolph","otherGeospatial":"White River","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.871309,43.647862 ], [ -72.871309,43.960964 ], [ -72.314788,43.960964 ], [ -72.314788,43.647862 ], [ -72.871309,43.647862 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a645f","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":240332,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":49833,"text":"ofr96567 - 1996 - Level II scour analysis for Bridge 41 (WODSTH00750041) on Town Highway 75, crossing Happy Valley Brook, Woodstock, Vermont","interactions":[],"lastModifiedDate":"2013-12-10T13:34:43","indexId":"ofr96567","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"96-567","title":"Level II scour analysis for Bridge 41 (WODSTH00750041) on Town Highway 75, crossing Happy Valley Brook, Woodstock, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure WODSTH00750041 on town highway 75 crossing Happy Valley Brook, Woodstock, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including a quantitative analysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of a Level I scour investigation also are included in Appendix E of this report. A Level I investigation provides a qualitative geomorphic characterization of the study site. Information on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is found in Appendix D.
\nThe site is in the New England Upland section of the New England physiographic province of east-central Vermont. The 3.45-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is brush with scattered trees.
\nIn the study area, Happy Valley Brook has an incised, sinuous channel with a slope of approximately 0.03 ft/ft, an average channel top width of 23 ft and an average channel depth of 5 ft. The predominant channel bed materials are gravel and cobble with a median grain size (D50) of 82.8 mm (0.272 ft). The geomorphic assessment at the time of the Level II site visits on September 13, 1994 and December 14, 1994, indicated that the reach was degrading. Five logs are embedded across the channel under the bridge in an attempt to prevent further degradation (see Figures 5 and 6).
\nThe town highway 75 crossing of Happy Valley Brook is a 27-ft-long, two-lane bridge consisting of one 25-foot steel-beam span. The clear span is 17 ft. (Vermont Agency of Transportation, written communication, August 3, 1994). The bridge is supported by vertical, stone abutments with wingwalls. The channel is skewed approximately 40 degrees to the opening and the opening-skew-to-roadway is also 40 degrees. Additional details describing conditions at the site are included in the Level II Summary and Appendices D and E.
\nScour depths and rock rip-rap sizes were computed using the general guidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995). Total scour at a highway crossing is comprised of three components: 1) long-term streambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is the sum of the three components. Equations are available to compute depths for contraction and local scour and a summary of the results of these computations follows.
\nContraction scour for all modelled flows ranged from 1.3 to 2.2 ft. The worst-case contraction scour occurred at the 500-year discharge. Abutment scour ranged from 7.2 to 12.0 ft. The worst-case abutment scour occurred at the 500-year discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution.
\nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, computed scour depths are evaluated in combination with other information including (but not limited to) historical performance during flood events, the geomorphic stability assessment, existing scour protection measures, and the results of the hydraulic analyses. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr96567","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Olson, S.A., 1996, Level II scour analysis for Bridge 41 (WODSTH00750041) on Town Highway 75, crossing Happy Valley Brook, Woodstock, Vermont: U.S. Geological Survey Open-File Report 96-567, iv, 48 p., https://doi.org/10.3133/ofr96567.","productDescription":"iv, 48 p.","numberOfPages":"53","costCenters":[],"links":[{"id":162557,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96567.PNG"},{"id":279294,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0567/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Woodstock","otherGeospatial":"Happy Valley Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.5,43.625 ], [ -72.5,43.75 ], [ -72.375,43.75 ], [ -72.375,43.625 ], [ -72.5,43.625 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a619d","contributors":{"authors":[{"text":"Olson, Scott A. 0000-0002-1064-2125 solson@usgs.gov","orcid":"https://orcid.org/0000-0002-1064-2125","contributorId":2059,"corporation":false,"usgs":true,"family":"Olson","given":"Scott","email":"solson@usgs.gov","middleInitial":"A.","affiliations":[{"id":405,"text":"NH/VT office of New England Water Science Center","active":true,"usgs":true}],"preferred":true,"id":240338,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":49832,"text":"ofr96566 - 1996 - Level II scour analysis for Bridge 96 (BLOOVT01050096) on Vermont Route 105, crossing Nulhegan River, Bloomfield, Vermont","interactions":[],"lastModifiedDate":"2013-12-10T13:38:00","indexId":"ofr96566","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"96-566","title":"Level II scour analysis for Bridge 96 (BLOOVT01050096) on Vermont Route 105, crossing Nulhegan River, Bloomfield, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure BLOOVT01050096 on Vermont Route 105 crossing the Nulhegan River, Bloomfield, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including a quantitative analysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of a Level I scour investigation also are included in Appendix E of this report. A Level I investigation provides a qualitative geomorphic characterization of the study site. Information on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is found in Appendix D.
\nThe site is in the White Mountain section of the New England physiographic province of north-east Vermont in the town of Bloomfield. The 103-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is shrub and brushland upstream. Downstream of the bridge, the surface cover is forest.
\nIn the study area, the Nulhegan River has an incised, sinuous channel with a slope of approximately 0.015 ft/ft, an average channel top width of 78 ft and an average channel depth of 5 ft. The predominant channel bed material is cobble with a median grain size (D50) of 133 mm (0.435 ft). About 100 feet upstream, the streambed and bank materials abruptly change predominantly to sand. The geomorphic assessment at the time of the Level I and Level II site visit on July 6, 1995, indicated that the upstream reach, which is experiencing channel scour and severe bank cutting into the alluvial channel boundaries, is not stable. The downstream reach is semi- to non-alluvial and is assessed as stable.
\nThe Vermont Route 105 crossing of the Nulhegan River is a 74-ft-long, two-lane bridge consisting of one 71-foot steel stringer type superstructure with a concrete deck (Vermont Agency of Transportation, written communication, August 5, 1994). The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 10 degrees to the opening while the opening-skew-to-roadway is 25 degrees.
\nA scour hole 4.0 ft deeper than the mean thalweg depth was observed along the upstream channel during the Level I assessment. Scour protection measures at the site consist of type-2 stone fill (less than 24 inches diameter) along the entire base length of both abutments and all wingwalls. Additional details describing conditions at the site are included in the Level II Summary and Appendices D\nand E.
\nScour depths and rock rip-rap sizes were computed using the general guidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995). Total scour at a highway crossing is comprised of three components: 1) long-term streambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is the sum of the three components. Equations are available to compute depths for contraction and local scour and a summary of the results of these computations follows.
\nContraction scour for all modelled flows ranged from 0.5 to 1.1 ft. The worst-case contraction scour occurred at the 500-year discharge. Abutment scour ranged from 10.5 to 16.2 ft. The worst-case abutment scour also occurred at the 500-year discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution.
\nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, computed scour depths are evaluated in combination with other information including (but not limited to) historical performance during flood events, the geomorphic stability assessment, existing scour protection measures, and the results of the hydraulic analyses. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr96566","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Ayotte, J., and Ivanoff, M.A., 1996, Level II scour analysis for Bridge 96 (BLOOVT01050096) on Vermont Route 105, crossing Nulhegan River, Bloomfield, Vermont: U.S. Geological Survey Open-File Report 96-566, iv, 48 p., https://doi.org/10.3133/ofr96566.","productDescription":"iv, 48 p.","numberOfPages":"53","costCenters":[],"links":[{"id":162556,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96566.PNG"},{"id":279295,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0566/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Bloomfield","otherGeospatial":"Nulhegan River","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -71.75,44.75 ], [ -71.75,44.875 ], [ -71.625,44.875 ], [ -71.625,44.75 ], [ -71.75,44.75 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b16e4b07f02db6a559d","contributors":{"authors":[{"text":"Ayotte, Joseph D. jayotte@usgs.gov","contributorId":1802,"corporation":false,"usgs":true,"family":"Ayotte","given":"Joseph D.","email":"jayotte@usgs.gov","affiliations":[{"id":466,"text":"New England Water Science Center","active":true,"usgs":true}],"preferred":false,"id":240336,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Ivanoff, Michael A.","contributorId":27105,"corporation":false,"usgs":true,"family":"Ivanoff","given":"Michael","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":240337,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49839,"text":"ofr96582 - 1996 - Level II scour analysis for Bridge 32 (CONCTH00030032) on Town Highway 3, crossing the Moose River, Concord, Vermont","interactions":[],"lastModifiedDate":"2013-12-05T16:07:22","indexId":"ofr96582","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"96-582","title":"Level II scour analysis for Bridge 32 (CONCTH00030032) on Town Highway 3, crossing the Moose River, Concord, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nCONCTH00030032 on Town Highway 3 crossing the Moose River, Concord, Vermont \n(figures 1–8). A Level II study is a basic engineering analysis of the site, including a \nquantitative analysis of stream stability and scour (U.S. Department of Transportation, \n1993). Results of a Level I scour investigation also are included in Appendix E of this \nreport. A Level I investigation provides a qualitative geomorphic characterization of the \nstudy site. Information on the bridge, gleaned from Vermont Agency of Transportation \n(VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is \nfound in Appendix D.\nApproximately 85 percent of the drainage above the site is in the White Mountain section \nand 15 percent is in the New England Upland section of the New England physiographic \nprovince in northeastern Vermont. The 98.7-mi2\n drainage area is in a predominantly rural \nand forested basin. In the vicinity of the study site, the surface cover is primarily grass with \nseveral houses and other buildings while the immediate channel banks have dense woody \nvegetation.\nIn the study area, the Moose River has an incised, sinuous channel with a slope of \napproximately 0.01 ft/ft, an average channel top width of 83 ft and an average channel \ndepth of 3 ft. The predominant channel bed material is cobble with a median grain size \n(D50) of 86.2 mm (0.283 ft). There are bedrock exposures downstream of the bridge. The \ngeomorphic assessment at the time of the Level I and Level II site visit on August 17, 1995, \nindicated that the reach was stable.\nThe Town Highway 3 crossing of the Moose River is a 96-ft-long, two-lane bridge \nconsisting of two steel-beam spans (Vermont Agency of Transportation, written \ncommunication, March 24, 1995). The bridge is supported by vertical, concrete abutments \nwith wingwalls and a concrete pier. The channel is skewed approximately 10 degrees to the \nopening while the opening-skew-to-roadway is 0 degrees. \nThe right upstream end of the pier is undermined by 1.3 feet. The footing of the right \nabutment is exposed by as much as 4.0 feet vertically. The footing of the downstream right \nwingwall is exposed 3.5 feet and the end of the wingwall has broken and fallen into the \nriver. Type-3 stone fill (less than 48 inches diameter) has been placed at the end of the \nexisting wingwall. Additional details describing conditions at the site are included in the \nLevel II Summary and Appendices \nD and E.\nScour depths and rock rip-rap sizes were computed using the general guidelines described \nin Hydraulic Engineering Circular 18 (Richardson and others, 1995). Total scour at a \nhighway crossing is comprised of three components: 1) long-term streambed degradation; \n2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) \nand; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is \nthe sum of the three components. Equations are available to compute depths for contraction \nand local scour and a summary of the results of these computations follows.\nContraction scour for all modelled flows ranged from 0.0 to 0.7 ft. Abutment scour ranged \nfrom 9.9 to 16.4 ft. Pier scour ranged from 14.4 to 16.2 ft. The worst-case contraction, \nabutment, and pier scour occurred at the 500-year discharge. Additional information on \nscour depths and depths to armoring are included in the section titled “Scour Results”. \nScoured-streambed elevations, based on the calculated scour depths, are presented in tables \n1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour \ndepths were calculated assuming an infinite depth of erosive material and a homogeneous \nparticle-size distribution. \nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.","language":"English","publisher":"U.S. Geological Survey","doi":"10.3133/ofr96582","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Olson, S.A., 1996, Level II scour analysis for Bridge 32 (CONCTH00030032) on Town Highway 3, crossing the Moose River, Concord, Vermont: U.S. Geological Survey Open-File Report 96-582, iv, 51 p., https://doi.org/10.3133/ofr96582.","productDescription":"iv, 51 p.","numberOfPages":"56","costCenters":[],"links":[{"id":162563,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96582.PNG"},{"id":279287,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0582/report.pdf"}],"country":"United States","state":"Vermont","city":"Concord","otherGeospatial":"Moose River","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -71.933288,44.35054 ], [ -71.933288,44.505065 ], [ -71.738643,44.505065 ], [ -71.738643,44.35054 ], [ -71.933288,44.35054 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4a7ee4b07f02db648627","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":240347,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":44374,"text":"ofr96651 - 1996 - Evaluation of shorelines along Lake Mohave, Lake Mead National Recreation Area, Nevada and Arizona","interactions":[],"lastModifiedDate":"2012-02-10T00:10:10","indexId":"ofr96651","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"96-651","title":"Evaluation of shorelines along Lake Mohave, Lake Mead National Recreation Area, Nevada and Arizona","docAbstract":"The hdpw (head-in-a-pumping-well) program described in this report is a post-processor that calculates the head in a pumping well based on thesimulated head at a finite-difference model cell that contains the well. The calculations are based on the Thiem equation. The hdpw code works with the U.S. Geological Survey modular finite-difference ground-water flow model, which is commonly called MODFLOW. The hdpw code is a complete program that has incorporated many of MODFLOW subroutines to read data. Code was added to the well package to calculate the head and drawdown in a fully-penetrating well of finite radius.","language":"ENGLISH","doi":"10.3133/ofr96651","usgsCitation":"Workman, J.B., 1996, Evaluation of shorelines along Lake Mohave, Lake Mead National Recreation Area, Nevada and Arizona: U.S. Geological Survey Open-File Report 96-651, 1 map : col. ; 113 x 46 cm., folded in envelope 22 x 24 cm. + 1 text (4 leaves ; 28 cm.), https://doi.org/10.3133/ofr96651.","productDescription":"1 map : col. ; 113 x 46 cm., folded in envelope 22 x 24 cm. + 1 text (4 leaves ; 28 cm.)","costCenters":[],"links":[{"id":168839,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/of/1996/0651/report-thumb.jpg"},{"id":81662,"rank":400,"type":{"id":17,"text":"Plate"},"url":"https://pubs.usgs.gov/of/1996/0651/plate-1.pdf","linkFileType":{"id":1,"text":"pdf"}},{"id":81663,"rank":300,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0651/report.pdf","linkFileType":{"id":1,"text":"pdf"}}],"scale":"100000","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -114.86666666666666,35 ], [ -114.86666666666666,36 ], [ -114.36749999999999,36 ], [ -114.36749999999999,35 ], [ -114.86666666666666,35 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4a09e4b07f02db5fab96","contributors":{"authors":[{"text":"Workman, Jeremiah B. 0000-0001-7816-6420 jworkman@usgs.gov","orcid":"https://orcid.org/0000-0001-7816-6420","contributorId":714,"corporation":false,"usgs":true,"family":"Workman","given":"Jeremiah","email":"jworkman@usgs.gov","middleInitial":"B.","affiliations":[{"id":318,"text":"Geosciences and Environmental Change Science Center","active":true,"usgs":true}],"preferred":true,"id":229659,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":23248,"text":"ofr96491 - 1996 - Initiation and frequency of debris flows in Grand Canyon, Arizona","interactions":[],"lastModifiedDate":"2020-12-01T22:02:28.399609","indexId":"ofr96491","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"96-491","displayTitle":"Initiation and Frequency of Debris Flows in Grand Canyon, Arizona","title":"Initiation and frequency of debris flows in Grand Canyon, Arizona","docAbstract":"Debris flows occur in 600 tributaries of the Colorado River in Grand Canyon, Arizona when intense precipitation causes slope failures in bedrock or colluvium. These slurries transport poorly sorted sediment, including very large boulders that form rapids at the mouths of tributaries and control the longitudinal profile of the Colorado River. Although the amount of rainfall on the days of historic debris flows typically is not unusual, the storm rainfall on consecutive days before the debris flows typically had recurrence intervals greater than 10 yrs. Four types of failure mechanisms initiate debris flows: bedrock failure (12 percent), failure of colluvial wedges by rainfall (21 percent), failure of colluvial wedges by runoff (the \"firehose effect;\" 36 percent), and combinations of these failure mechanisms (30 percent). Failure points are directly or indirectly associated with terrestrial shales, particularly the Permian Hermit Shale, shale units within the Permian Esplanade Sandstone of the Supai Group, and the Cambrian Bright Angel Shale. Shales either directly fail, produce colluvial wedges downslope that contain clay, or form benches that store poorly sorted colluvium in wedge-shaped deposits. Terrestrial shales provide the fine particles and clay minerals?particularly kaolinite and illite?essential to long-distance debris-flow transport, whereas marine shales mostly contain smectites, which inhibit debris-flow initiation. Using repeat photography, we determined whether or not a debris flow occurred in the last century in 164 of 600 tributaries in Grand Canyon. We used logistic regression to model the binomial frequency data using 21 morphometric and lithologic variables. The location of shale units, particularly the Hermit Shale, within the tributary is the most consistent variable related to debris-flow frequency in Grand Canyon. Other statistically significant variables vary with large scale changes in canyon morphology. Standard morphometric measures such as drainage-basin area, channel gradient, and aspect of the river corridor are the most significant variables in the narrow and deep eastern section of Grand Canyon. Measures of the location of source lithologies are more important in western Grand Canyon, which has broader and low-gradient drainages. Measures of geologic structure, and other standard hydrologic variates, were not significant. Our results show that the probability of debris-flow occurrence is highest in eastern Grand Canyon. Throughout Grand Canyon, the probability of debris-flow occurrence is highest in reaches of the Colorado River that trend south-southwest. This direction is significant because most summer storms originate from a southerly direction, and the maximum slope of the regional structure is to the southwest. The binomial frequency of debris flows is not random in Grand Canyon, and tributaries of similar debris-flow frequency are clustered in distinct reaches.
","language":"English","publisher":"U.S. Geological Survey","doi":"10.3133/ofr96491","usgsCitation":"Griffiths, P.G., Webb, R., and Melis, T., 1996, Initiation and frequency of debris flows in Grand Canyon, Arizona: U.S. Geological Survey Open-File Report 96-491, ii, 35 p., https://doi.org/10.3133/ofr96491.","productDescription":"ii, 35 p.","costCenters":[],"links":[{"id":154267,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/usgs_thumb.jpg"},{"id":1398,"rank":100,"type":{"id":15,"text":"Index Page"},"url":"https://pubs.water.usgs.gov/ofr96-491","linkFileType":{"id":5,"text":"html"}}],"country":"United States","state":"Arizona","otherGeospatial":"Colorado River, Grand Canyon","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"type\": \"Polygon\",\n \"coordinates\": [\n [\n [\n -114.01611328125,\n 35.68407153314097\n ],\n [\n -111.192626953125,\n 35.68407153314097\n ],\n [\n -111.192626953125,\n 36.958671131530316\n ],\n [\n -114.01611328125,\n 36.958671131530316\n ],\n [\n -114.01611328125,\n 35.68407153314097\n ]\n ]\n ]\n }\n }\n ]\n}","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e49e3e4b07f02db5e5cf0","contributors":{"authors":[{"text":"Griffiths, Peter G. 0000-0002-8663-8907 pggriffi@usgs.gov","orcid":"https://orcid.org/0000-0002-8663-8907","contributorId":187,"corporation":false,"usgs":true,"family":"Griffiths","given":"Peter","email":"pggriffi@usgs.gov","middleInitial":"G.","affiliations":[],"preferred":true,"id":189728,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Webb, Robert H. rhwebb@usgs.gov","contributorId":1573,"corporation":false,"usgs":false,"family":"Webb","given":"Robert H.","email":"rhwebb@usgs.gov","affiliations":[{"id":12625,"text":"School of Natural Resources and the Environment, University of Arizona, Tucson, AZ, 85721, USA","active":true,"usgs":false}],"preferred":false,"id":189729,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Melis, Theodore S. 0000-0003-0473-3968 tmelis@usgs.gov","orcid":"https://orcid.org/0000-0003-0473-3968","contributorId":1829,"corporation":false,"usgs":true,"family":"Melis","given":"Theodore S.","email":"tmelis@usgs.gov","affiliations":[{"id":568,"text":"Southwest Biological Science Center","active":true,"usgs":true}],"preferred":true,"id":189730,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":49796,"text":"ofr96241 - 1996 - Level II scour analysis for Bridge 45 (CHELTH00440045) on Town Highway 44, crossing first Branch White River, Chelsea, Vermont","interactions":[],"lastModifiedDate":"2013-12-11T11:07:51","indexId":"ofr96241","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"96-241","title":"Level II scour analysis for Bridge 45 (CHELTH00440045) on Town Highway 44, crossing first Branch White River, Chelsea, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nCHELTH00440045 on town highway 44 crossing the First Branch White River, Chelsea, \nVermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including \na quantitative analysis of stream stability and scour (U.S. Department of Transportation, \n1993). A Level I study is included in Appendix E of this report. A Level I study provides \na qualitative geomorphic characterization of the study site. Information on the bridge \navailable from VTAOT files was compiled prior to conducting Level I and Level II \nanalyses and can be found in Appendix D.
\nThe site is in the Green Mountain physiographic province of central Vermont in the town of \nChelsea. The 32.5-mi2\n drainage area is in a predominantly rural and forested basin. In the \nvicinity of the study site, the banks have low to moderate woody vegetation coverage except \nfor the upstream right bank, which is grass covered. The immediate vicinity of the site is \nsuburban and the overbank areas are occupied by houses, driveways, and lawn areas. The \nupstream right bank area is a dirt parking lot for a small auto repair garage.
\nIn the study area, the First Branch White River has an incised, sinuous channel with a slope \nof approximately 0.003 ft/ft, an average channel top width of 41 ft and an average channel \ndepth of 4 ft. The predominant channel bed material is gravel (D50 is 43.1 mm or 0.141 ft). \nThe geomorphic assessment at the time of the Level I and Level II site visit on November \n17, 1994, indicated that the reach was stable.
\nThe town highway 44 crossing of the First Branch White Riveris a 31-ft-long, two-lane\nbridge consisting of one 27-foot clear-span concrete-encased steel beam deck \nsuperstructure (Vermont Agency of Transportation, written commun., August 25, 1994). \nThe bridge is supported by vertical, concrete abutments with wingwalls. The channel is \nskewed approximately 10 degrees to the opening while the opening-skew-to-roadway is 5 \ndegrees.
\nBoth abutment footings were reported as exposed and the left abutment was reported to be \nundermined by 0.5 ft at the time of the Level I assessment. The only scour protection \nmeasure at the site was type-1 stone fill (less than 12 inches diameter) along the left \nabutment which was reported as failed. Additional details describing conditions at the site \nare included in the Level II Summary and Appendices D and E.
\nScour depths and rock rip-rap sizes were computed using the general guidelines described \nin Hydraulic Engineering Circular 18 (Richardson and others, 1993). Total scour at a \nhighway crossing is comprised of three components: 1) long-term streambed degradation; \n2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) \nand; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is \nthe sum of the three components. Equations are available to compute depths for contraction \nand local scour and a summary of the results of these computations follows.
\nContraction scour for all modelled flows ranged from 0.4 to 5.1 ft. with the worst-case \noccurring at the 500-year discharge. Abutment scour ranged from 9.9 to 20.3 ft. The worst-case abutment scour also occurred at the 500-year discharge. Additional information on \nscour depths and depths to armoring are included in the section titled “Scour Results”. \nScoured-streambed elevations, based on the calculated scour depths, are presented in tables \n1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour \ndepths were calculated assuming an infinite depth of erosive material and a homogeneous \nparticle-size distribution.
\nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1993, p. 48). Many factors, \nincluding historical performance during flood events, the geomorphic assessment, scour \nprotection measures, and the results of the hydraulic analyses, must be considered to \nproperly assess the validity of abutment scour results. Therefore, scour depths adopted by \nVTAOT may differ from the computed values documented herein, based on the \nconsideration of additional contributing factors and experienced engineering judgement.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr96241","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Ayotte, J., and Hammond, R.E., 1996, Level II scour analysis for Bridge 45 (CHELTH00440045) on Town Highway 44, crossing first Branch White River, Chelsea, Vermont: U.S. Geological Survey Open-File Report 96-241, iv, 31 p., https://doi.org/10.3133/ofr96241.","productDescription":"iv, 31 p.","numberOfPages":"36","costCenters":[],"links":[{"id":179184,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96241.GIF"},{"id":279386,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0241/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Chelsea","otherGeospatial":"First Branch White River","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.5,43.875 ], [ -72.5,44.0 ], [ -72.375,44.0 ], [ -72.375,43.875 ], [ -72.5,43.875 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a611f","contributors":{"authors":[{"text":"Ayotte, Joseph D. jayotte@usgs.gov","contributorId":1802,"corporation":false,"usgs":true,"family":"Ayotte","given":"Joseph D.","email":"jayotte@usgs.gov","affiliations":[{"id":466,"text":"New England Water Science Center","active":true,"usgs":true}],"preferred":false,"id":240273,"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":240274,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49792,"text":"ofr96236 - 1996 - Level II scour analysis for Bridge 34 (RANDTH00660034) on Town Highway 66, crossing Second Branch White River, Randolph, Vermont","interactions":[],"lastModifiedDate":"2013-12-11T11:46:46","indexId":"ofr96236","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"96-236","title":"Level II scour analysis for Bridge 34 (RANDTH00660034) on Town Highway 66, crossing Second Branch White River, Randolph, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nRANDTH00660034 on town highway 66 crossing the Second Branch White River, \nRandolph, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the \nsite, including a quantitative analysis of stream stability and scour (U.S. Department of \nTransportation, 1993). A Level I study is included in Appendix E of this report. A Level I \nstudy provides a qualitative geomorphic characterization of the study site. Information on \nthe bridge available from VTAOT files was compiled prior to conducting Level I and Level \nII analyses and can be found in Appendix D.
\nThe site is in the Green Mountain physiographic division of central Vermont in the town of \nRandolph. The 51.3-mi2\n drainage area is in a predominantly rural basin. In the vicinity of \nthe study site, the left and right banks are covered by fields with some brush on the \nupstream left and downstream right banks and with row crops on the downstream left \noverbank.
\nIn the study area, the Second Branch White River has a sinuous channel with a slope of \napproximately 0.002 ft/ft, an average channel top width of 60 ft and an average channel \ndepth of 7 ft. The predominant channel bed material is sand (D50 is 1.34 mm or 0.0044 ft). \nThe geomorphic assessment at the time of the Level I and Level II site visit on August 11, \n1994, indicated that the reach was laterally unstable. Channel scour is evident along the left \nhalf of the channel from about 30 feet upstream to about 20 feet downstream of the bridge. \nThere is a cut bank with block failures along the left bank upstream of the bridge further \nindicating instability of the stream reach.
\nThe town highway 66 crossing of the Second Branch White Riveris a 57-ft-long, one-lane\ncovered bridge consisting of one 45-foot span (Vermont Agency of Transportation, written \ncommunication, July 29, 1994). The bridge is supported by vertical, concrete abutments \nwith one wingwall on the upstream left side. The base of the left abutment was protected by \ntype-1 stone fill (less than 12 inches diameter). The channel is skewed approximately 40 \ndegrees to the opening while the opening-skew-to-roadway is 45 degrees. Additional details \ndescribing conditions at the site are included in the Level II Summary and Appendices D \nand E.
\nScour depths and rock rip-rap sizes were computed using the general guidelines described \nin Hydraulic Engineering Circular 18 (Richardson and others, 1993).\nTotal scour at a highway crossing is comprised of three components: 1) long-term \naggradation or degradation; 2) contraction scour (due to reduction in flow area caused by a \nbridge) and; 3) local scour (caused by accelerated flow around piers and abutments). Total \nscour is the sum of the three components. Equations are available to compute scour depths \nfor contraction and local scour and a summary of the results follows.
\nContraction scour for all modelled flows ranged from 6.3 ft to 7.8 ft and the worst-case \ncontraction scour occurred at the 100-year discharge. Abutment scour ranged from 7.9 ft to \n20.3 ft and the worst-case abutment scour occurred at the 500-year discharge. Scour depths \nand depths to armoring are summarized on p. 14 in the section titled “Scour Results”. \nScour elevations, based on the calculated depths are presented in tables 1 and 2; a graph of \nthe scour elevations is presented in figure 8 Scour depths were calculated assuming an \ninfinite depth of erosive material and a homogeneous particle-size distribution.
\nFor all scour presented in this report, “the scour depths adopted [by VTAOT] may differ \nfrom the equation values based on engineering judgement” (Richardson and others, 1993, p. \n21, 27). It is generally accepted that the Froehlich equation (abutment scour) gives \n“excessively conservative estimates of scour depths” (Richardson and others, 1993, p. 48). \nMany factors, including historical performance during flood events, the geomorphic \nassessment, and the results of the hydraulic analyses, must be considered to properly assess \nthe validity of abutment scour results.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr96236","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Olson, S.A., and Ayotte, J., 1996, Level II scour analysis for Bridge 34 (RANDTH00660034) on Town Highway 66, crossing Second Branch White River, Randolph, Vermont: U.S. Geological Survey Open-File Report 96-236, iv, 30 p., https://doi.org/10.3133/ofr96236.","productDescription":"iv, 30 p.","numberOfPages":"35","costCenters":[],"links":[{"id":179180,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96236.GIF"},{"id":279391,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0236/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Randolph","otherGeospatial":"Second Branch White River","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.625,43.875 ], [ -72.625,44.0 ], [ -72.5,44.0 ], [ -72.5,43.875 ], [ -72.625,43.875 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a64ed","contributors":{"authors":[{"text":"Olson, Scott A. 0000-0002-1064-2125 solson@usgs.gov","orcid":"https://orcid.org/0000-0002-1064-2125","contributorId":2059,"corporation":false,"usgs":true,"family":"Olson","given":"Scott","email":"solson@usgs.gov","middleInitial":"A.","affiliations":[{"id":405,"text":"NH/VT office of New England Water Science Center","active":true,"usgs":true}],"preferred":true,"id":240267,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Ayotte, Joseph D. jayotte@usgs.gov","contributorId":1802,"corporation":false,"usgs":true,"family":"Ayotte","given":"Joseph D.","email":"jayotte@usgs.gov","affiliations":[{"id":466,"text":"New England Water Science Center","active":true,"usgs":true}],"preferred":false,"id":240266,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49795,"text":"ofr96240 - 1996 - Level II scour analysis for Bridge 51 (RANDTH00SC0051) on School Street, crossing Thayer Brook, Randolph, Vermont","interactions":[],"lastModifiedDate":"2013-12-11T11:14:03","indexId":"ofr96240","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"96-240","title":"Level II scour analysis for Bridge 51 (RANDTH00SC0051) on School Street, crossing Thayer Brook, Randolph, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nRANDTH00SC0051 on School Street crossing Thayer Brook, Randolph, Vermont (figures \n1–8). A Level II study is a basic engineering analysis of the site, including a quantitative \nanalysis of stream stability and scour (U.S. Department of Transportation, 1993). A Level \nI study is included in Appendix E of this report. A Level I study provides a qualitative \ngeomorphic characterization of the study site. Information on the bridge available from \nVTAOT files was compiled prior to conducting Level I and Level II analyses and can be \nfound in Appendix D.
\nThe site is in the Green Mountain physiographic division of central Vermont in the town of \nRandolph. The 5.30-mi2\n drainage area is a predominantly rural basin. In the vicinity of the \nstudy site, the left and right banks are forested with residences on the left overbanks.
\nIn the study area, Thayer Brook has a sinuous channel with a slope of approximately 0.03 ft/\nft, an average channel top width of 36 ft and an average channel depth of 3 ft. The \npredominant channel bed materials are gravel and cobble (D50 is 58.2 mm or 0.191 ft). The \ngeomorphic assessment at the time of the Level I site visits on August 4, 1994 and \nDecember 8, 1994, indicated that the reach was stable.
\nThe School Street crossing of Thayer Brook is a 39-ft-long, two-lane bridge consisting of \none 35-foot concrete span (Vermont Agency of Transportation, written commun., August 2, \n1994). The bridge is supported by vertical, concrete abutments with wingwalls. Type-2 \nstone fill (less than 36 inches diameter) along the downstream left bank was the only \nexisting protection. The approach channel is skewed approximately 45 degrees to the bridge \nface; the opening-skew-to-roadway is also 45 degrees. Additional details describing \nconditions at the site are included in the Level II Summary, Appendix D, and Appendix E.
\nScour depths and rock rip-rap sizes were computed using the general guidelines described \nin Hydraulic Engineering Circular 18 (Richardson and others, 1993). Total scour at a \nhighway crossing is comprised of three components: 1) long-term streambed degradation; \n2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) \nand; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is \nthe sum of the three components. Equations are available to compute depths for contraction \nand local scour and a summary of the results of these computations follows.
\nContraction scour for all modelled flows ranged from 1.0 to 2.2 ft. with the worst-case \nscenario occurring at the 500-year discharge. Abutment scour ranged from 6.2 to 12.0 ft. \nThe worst-case abutment scour also occurred at the 500-year discharge. Additional \ninformation on scour depths and depths to armoring are included in the section titled “Scour \nResults”. Scoured-streambed elevations, based on the calculated scour depths, are presented \nin tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure \n8. Scour depths were calculated assuming an infinite depth of erosive material and a \nhomogeneous particle-size distribution.
\nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1993, p. 48). Many factors, \nincluding historical performance during flood events, the geomorphic assessment, scour \nprotection measures, and the results of the hydraulic analyses, must be considered to \nproperly assess the validity of abutment scour results. Therefore, scour depths adopted by \nVTAOT may differ from the computed values documented herein, based on the \nconsideration of additional contributing factors and experienced engineering judgement.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr96240","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Olson, S.A., 1996, Level II scour analysis for Bridge 51 (RANDTH00SC0051) on School Street, crossing Thayer Brook, Randolph, Vermont: U.S. Geological Survey Open-File Report 96-240, iv, 28 p., https://doi.org/10.3133/ofr96240.","productDescription":"iv, 28 p.","numberOfPages":"33","costCenters":[],"links":[{"id":179183,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96240.GIF"},{"id":279388,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0240/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Randolph","otherGeospatial":"Thayer Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.75,43.875 ], [ -72.75,44.0 ], [ -72.625,44.0 ], [ -72.625,43.875 ], [ -72.75,43.875 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a5b7a","contributors":{"authors":[{"text":"Olson, Scott A. 0000-0002-1064-2125 solson@usgs.gov","orcid":"https://orcid.org/0000-0002-1064-2125","contributorId":2059,"corporation":false,"usgs":true,"family":"Olson","given":"Scott","email":"solson@usgs.gov","middleInitial":"A.","affiliations":[{"id":405,"text":"NH/VT office of New England Water Science Center","active":true,"usgs":true}],"preferred":true,"id":240272,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":49793,"text":"ofr96237 - 1996 - Level II scour analysis for Bridge 3 (BRIDTH000100003) on Town Highway 1, crossing Dailey Hollow Branch, Bridgewater, Vermont","interactions":[],"lastModifiedDate":"2013-12-11T11:34:45","indexId":"ofr96237","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"96-237","title":"Level II scour analysis for Bridge 3 (BRIDTH000100003) on Town Highway 1, crossing Dailey Hollow Branch, Bridgewater, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nBRIDTH00010003 on town highway 1 crossing Dailey Hollow Branch, Bridgewater, \nVermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including \na quantitative analysis of stream stability and scour (U.S. Department of Transportation, \n1993). A Level I study is included in Appendix E of this report. A Level I study provides \na qualitative geomorphic characterization of the study site. Information on the bridge \navailable from VTAOT files was compiled prior to conducting Level I and Level II \nanalyses and can be found in Appendix D.
\nThe site is in the Green Mountain physiographic division of central Vermont in the town of \nBridgewater. The 9.88-mi2\n drainage area is in a predominantly rural, forested basin. In the \nvicinity of the study site, the immediate channel banks have moderate tree cover and shrubs \nwith residential properties on the overbank.
\nIn the study area, Dailey Hollow Branch has an incised, sinuous channel with a slope of \napproximately 0.009 ft/ft, an average channel top width of 46 ft and an average channel \ndepth of 4 ft. The predominant channel bed materials are gravel and cobble with a median \ngrain size (D50) of 89.7 mm (0.294 ft). The geomorphic assessment at the time of the Level \nI and Level II site visit on October 27, 1994, indicated that the reach was vertically \ndegrading.
\nThe town highway 1 crossing of Dailey Hollow Branch is a 45-ft-long, two-lane bridge \nconsisting of one 42-foot steel-beam span (Vermont Agency of Transportation, written \ncommunication, August 24, 1994). The bridge is supported by vertical, concrete abutments \nwith wingwalls. Type-2 stone fill (less than 36 inches diameter) protects the downstream \nright and left wingwall. Type-3 stone fill (less than 48 inches diameter) exists on the \ndownstream right bank. The left abutment is undermined by up to one foot. Horizontal \nprobing under the abutment resulted in penetration up to 6 feet.
\nThe bridge is misaligned with the channel. Higher discharges may directly impact the left \nwingwall. The channel is skewed approximately 20 degrees to the bridge; the opening-skew-to-roadway is also 20 degrees. Additional details describing conditions at the site are \nincluded in the Level II Summary and Appendices D \nand E.
\nScour depths and rock rip-rap sizes were computed using the general guidelines described \nin Hydraulic Engineering Circular 18 (Richardson and others, 1993).\nTotal scour at a highway crossing is comprised of three components: 1) long-term \naggradation or degradation; 2) contraction scour (due to reduction in flow area caused by a \nbridge) and; 3) local scour (caused by accelerated flow around piers and abutments). Total \nscour is the sum of the three components. Equations are available to compute scour depths \nfor contraction and local scour and a summary of the results follows.
\nContraction scour for all modelled flows ranged from 0.6 ft to 1.3 ft and the worst-case \ncontraction scour occurred at the 500-year discharge. Abutment scour ranged from 6.7 ft to \n12.2 ft and the worst-case abutment scour occurred at the 500-year discharge. Scour depths \nand depths to armoring are summarized on p. 14 in the section titled “Scour Results”. \nScour elevations, based on the calculated depths are presented in tables 1 and 2; a graph of \nthe scour elevations is presented in figure 8 Scour depths were calculated assuming an \ninfinite depth of erosive material and a homogeneous particle-size distribution.
\nFor all scour presented in this report, “the scour depths adopted [by VTAOT] may differ \nfrom the equation values based on engineering judgement” (Richardson and others, 1993, p. \n21, 27). It is generally accepted that the Froehlich equation (abutment scour) gives \n“excessively conservative estimates of scour depths” (Richardson and others, 1993, p. 48). \nMany factors, including historical performance during flood events, the geomorphic \nassessment, and the results of the hydraulic analyses, must be considered to properly assess \nthe validity of abutment scour results.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr96237","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Olson, S.A., and Song, D.L., 1996, Level II scour analysis for Bridge 3 (BRIDTH000100003) on Town Highway 1, crossing Dailey Hollow Branch, Bridgewater, Vermont: U.S. Geological Survey Open-File Report 96-237, iv, 27 p., https://doi.org/10.3133/ofr96237.","productDescription":"iv, 27 p.","numberOfPages":"32","costCenters":[],"links":[{"id":179181,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96237.GIF"},{"id":279390,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0237/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Bridgewater","otherGeospatial":"Dailey Hollow Branch","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.75,43.5 ], [ -72.75,43.625 ], [ -72.625,43.625 ], [ -72.625,43.5 ], [ -72.75,43.5 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b19e4b07f02db6a7f05","contributors":{"authors":[{"text":"Olson, Scott A. 0000-0002-1064-2125 solson@usgs.gov","orcid":"https://orcid.org/0000-0002-1064-2125","contributorId":2059,"corporation":false,"usgs":true,"family":"Olson","given":"Scott","email":"solson@usgs.gov","middleInitial":"A.","affiliations":[{"id":405,"text":"NH/VT office of New England Water Science Center","active":true,"usgs":true}],"preferred":true,"id":240268,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Song, Donald L.","contributorId":107335,"corporation":false,"usgs":true,"family":"Song","given":"Donald","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":240269,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49806,"text":"ofr96308 - 1996 - Level II scour analysis for Bridge 54 (RANDTH00BR0054) on Brook Street, crossing Thayer Brook, Randolph, Vermont","interactions":[],"lastModifiedDate":"2013-12-11T09:22:00","indexId":"ofr96308","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"96-308","title":"Level II scour analysis for Bridge 54 (RANDTH00BR0054) on Brook Street, crossing Thayer Brook, Randolph, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nRANDTH00BR0054 on Brook Street crossing Thayer Brook, Randolph, Vermont (figures \n1–8). A Level II study is a basic engineering analysis of the site, including a quantitative \nanalysis of stream stability and scour (U.S. Department of Transportation, 1993). A Level \nI study is included in Appendix E of this report. A Level I study provides a qualitative \ngeomorphic characterization of the study site. Information on the bridge available from \nVTAOT files was compiled prior to conducting Level I and Level II analyses and can be \nfound in Appendix D.
\nThe site is in the Green Mountain physiographic division of central Vermont in the town of \nRandolph. The 5.39-mi2\n drainage area is in a predominantly rural basin. In the vicinity of \nthe study site, the immediate banks are forested.
\nIn the study area, Thayer Brook has an incised, sinuous channel with a slope of \napproximately 0.03 ft/ft, an average channel top width of 60 ft and an average channel \ndepth of 3 ft. The predominant channel bed materials are gravel and cobble (D50 is 42.4 mm \nor 0.139 ft). The geomorphic assessment at the time of the Level I and Level II site visits on \nAugust 3, 1994 and December 5, 1994, indicated that the reach was vertically and laterally \nunstable. This assessment was due to the extreme channel misalignment with the bridge \nopening and the presence of a drop structure downstream of the bridge protecting against \nchannel degradation.
\nThe Brook Street crossing of Thayer Brook is a 34-ft-long, two-lane bridge consisting of \none 31-foot concrete span (Vermont Agency of Transportation, written communication, \nAugust 2, 1994). The bridge is supported by vertical, concrete abutments with wingwalls. \nStreamflow attacks the upstream right wingwall and has undermined the upstream end of \nthe right abutment. Type-2 stone fill (less than 36 inches diameter) exists only on the \nupstream and downstream sides of the left road embankment. No other protection was \nnoted. The bank full channel skew at the bridge face is approximately 20 degrees; the \nopening-skew-to-roadway is also 20 degrees. Additional details describing conditions at the \nsite are included in the Level II Summary and Appendices D \nand E.
\nScour depths and rock rip-rap sizes were computed using the general guidelines described \nin Hydraulic Engineering Circular 18 (Richardson and others, 1993). Total scour at a \nhighway crossing is comprised of three components: 1) long-term streambed degradation; \n2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) \nand; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is \nthe sum of the three components. Equations are available to compute depths for contraction \nand local scour and a summary of the results of these computations follows.
\nContraction scour for all modelled flows ranged from 1.3 to 2.7 ft. The worst-case \ncontraction scour occurred at the 500-year discharge. Abutment scour ranged from 5.3 to \n15.1 ft. and the worst-case abutment scour also occurred at the 500-year discharge. \nAdditional information on scour depths and depths to armoring are included in the section \ntitled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, \nare presented in tables 1 and 2. A cross-section of the scour computed at the bridge is \npresented in figure 8. Scour depths were calculated assuming an infinite depth of erosive \nmaterial and a homogeneous particle-size distribution.
\nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1993, p. 48). Many factors, \nincluding historical performance during flood events, the geomorphic assessment, scour \nprotection measures, and the results of the hydraulic analyses, must be considered to \nproperly assess the validity of abutment scour results. Therefore, scour depths adopted by \nVTAOT may differ from the computed values documented herein, based on the \nconsideration of additional contributing factors and experienced engineering judgement.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr96308","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Olson, S.A., 1996, Level II scour analysis for Bridge 54 (RANDTH00BR0054) on Brook Street, crossing Thayer Brook, Randolph, Vermont: U.S. Geological Survey Open-File Report 96-308, iv, 27 p., https://doi.org/10.3133/ofr96308.","productDescription":"iv, 27 p.","numberOfPages":"32","costCenters":[],"links":[{"id":179405,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96308.GIF"},{"id":279375,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0308/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Randolph","otherGeospatial":"Thayer Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.75,43.875 ], [ -72.75,44.0 ], [ -72.625,44.0 ], [ -72.625,43.875 ], [ -72.75,43.875 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a5a8d","contributors":{"authors":[{"text":"Olson, Scott A. 0000-0002-1064-2125 solson@usgs.gov","orcid":"https://orcid.org/0000-0002-1064-2125","contributorId":2059,"corporation":false,"usgs":true,"family":"Olson","given":"Scott","email":"solson@usgs.gov","middleInitial":"A.","affiliations":[{"id":405,"text":"NH/VT office of New England Water Science Center","active":true,"usgs":true}],"preferred":true,"id":240292,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":49791,"text":"ofr96234 - 1996 - Level II scour analysis for Bridge 39 (RANDTH00730039) on Town Highway 73, crossing the Second Branch White River, Randolph, Vermont","interactions":[],"lastModifiedDate":"2013-12-11T12:43:20","indexId":"ofr96234","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"96-234","title":"Level II scour analysis for Bridge 39 (RANDTH00730039) on Town Highway 73, crossing the Second Branch White River, Randolph, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nRANDTH00730039 on town highway 73 crossing the Second Branch White River, \nRandolph, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the \nsite, including a quantitative analysis of stream stability and scour (U.S. Department of \nTransportation, 1993). A Level I study is included in Appendix E of this report. A Level I \nstudy provides a qualitative geomorphic characterization of the study site. Information on \nthe bridge available from VTAOT files was compiled prior to conducting Level I and Level \nII analyses and can be found in Appendix D.
\nThe site is in the Green Mountain physiographic province of central Vermont in the town of \nRandolph. The 53.7-mi2\n drainage area is in a predominantly rural basin. In the vicinity of \nthe study site, the overbanks are covered by pasture except for the upstream right bank \nwhich is covered by brush.
\nIn the study area, the Second Branch White River has a meandering channel with a slope of \napproximately 0.001 ft/ft, an average channel top width of 44 ft and an average channel \ndepth of 6 ft. The predominant channel bed material is sand with median grain size (D50) of \n0.884 mm (0.0029 ft). The geomorphic assessment at the time of the Level I and Level II \nsite visit on August 12, 1994, indicated that the reach was laterally unstable. This is because \nof severe cut-banks both upstream and downstream where mass wasting and block failure \nof bank material is evident. Furthermore, minimal erosion protection is provided by bank \nvegetation since woody vegetation cover is sparse.
\nThe town highway 73 crossing of the Second Branch White Riveris a 42-ft-long, one-lane\nbridge consisting of one 40-foot span (Vermont Agency of Transportation, written \ncommunication, August 2, 1994). The bridge is supported by vertical, concrete abutments \nwith wingwalls. The ends of the upstream left wingwall and the downstream right wingwall \nare protected by stone fill. However, this stone fill is slumping according to the Level I field \ninspection. The channel is skewed approximately 30 degrees to the opening while the \nopening-skew-to-roadway is 0 degrees. Additional details describing conditions at the site \nare included in the Level II Summary and Appendices D and E.
\nScour depths and rock rip-rap sizes were computed using the general guidelines described \nin Hydraulic Engineering Circular 18 (Richardson and others, 1993).\nTotal scour at a highway crossing is comprised of three components: 1) long-term \naggradation or degradation; 2) contraction scour (due to reduction in flow area caused by a \nbridge) and; 3) local scour (caused by accelerated flow around piers and abutments). Total \nscour is the sum of the three components. Equations are available to compute scour depths \nfor contraction and local scour and a summary of the results follows.
\nContraction scour for all modelled flows ranged from 1.9 ft to 4.6 ft and the worst-case \ncontraction scour occurred at the incipient overtopping discharge. Abutment scour ranged \nfrom 4.0 ft to 22.5 ft and the worst-case abutment scour occurred at the 500-year discharge. \nScour depths and depths to armoring are summarized on p. 14 in the section titled “Scour \nResults”. Scour elevations, based on the calculated depths are presented in tables 1 and 2; \na graph of the scour elevations is presented in figure 8 Scour depths were calculated \nassuming an infinite depth of erosive material and a homogeneous particle-size distribution.
\nFor all scour presented in this report, “the scour depths adopted [by VTAOT] may differ \nfrom the equation values based on engineering judgement” (Richardson and others, 1993, p. \n21, 27). It is generally accepted that the Froehlich equation (abutment scour) gives \n“excessively conservative estimates of scour depths” (Richardson and others, 1993, p. 48). \nMany factors, including historical performance during flood events, the geomorphic \nassessment, and the results of the hydraulic analyses, must be considered to properly assess \nthe validity of abutment scour results.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr96234","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Song, D.L., and Ivanoff, M.A., 1996, Level II scour analysis for Bridge 39 (RANDTH00730039) on Town Highway 73, crossing the Second Branch White River, Randolph, Vermont: U.S. Geological Survey Open-File Report 96-234, iv, 30 p., https://doi.org/10.3133/ofr96234.","productDescription":"iv, 30 p.","numberOfPages":"35","costCenters":[],"links":[{"id":179179,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96234.GIF"},{"id":279392,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0234/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Randolph","otherGeospatial":"Second Branch White River","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.625,43.875 ], [ -72.625,44.0 ], [ -72.5,44.0 ], [ -72.5,43.875 ], [ -72.625,43.875 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a62b0","contributors":{"authors":[{"text":"Song, Donald L.","contributorId":107335,"corporation":false,"usgs":true,"family":"Song","given":"Donald","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":240265,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Ivanoff, Michael A.","contributorId":27105,"corporation":false,"usgs":true,"family":"Ivanoff","given":"Michael","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":240264,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49794,"text":"ofr96239 - 1996 - Level II scour analysis for Bridge 35 (BETHTH00190035) on Town Highway 19, crossing Gilead Brook, Bethel, Vermont","interactions":[],"lastModifiedDate":"2013-12-11T11:20:02","indexId":"ofr96239","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"96-239","title":"Level II scour analysis for Bridge 35 (BETHTH00190035) on Town Highway 19, crossing Gilead Brook, Bethel, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nBETHTH00190035 on town highway 19 crossing Gilead Brook, Bethel, Vermont (figures \n1–8). A Level II study is a basic engineering analysis of the site, including a quantitative \nanalysis of stream stability and scour (U.S. Department of Transportation, 1993). A Level \nI study is included in Appendix E of this report. A Level I study provides a qualitative \ngeomorphic characterization of the study site. Information on the bridge available from \nVTAOT files was compiled prior to conducting Level I and Level II analyses and can be \nfound in Appendix D.
\nThe site is in the Green Mountain physiographic province of central Vermont in the town of \nBethel. The 6.40-mi2\n drainage area is predominantly rural and forested. In the vicinity of \nthe study site, the immediate banks have woody vegetation coverage with pasture beyond.
\nIn the study area, Gilead Brook is an incised, sinuous channel with a slope of approximately \n0.015 ft/ft, an average channel top width of 31 ft and an average channel depth of 2.5 ft. The \npredominant channel bed material is gravel and cobble (D50 is 62.5 mm or 0.205 ft). The \ngeomorphic assessment at the time of the Level I and Level II site visit on October 20, \n1994, indicated that the reach was stable.
\nThe town highway 19 crossing of Gilead Brook is a 30-ft-long, one-lane bridge consisting \nof one 24-foot steel-beam span with timber deck (Vermont Agency of Transportation, \nwritten commun., August 24, 1994). The bridge is supported by vertical, concrete\nabutments with wingwalls. The channel is skewed approximately 5 degrees to the opening \nwhile the opening-skew-to-roadway is 10 degrees.
\nThe scour protection measures at the site included type-1 stone fill (less than 12 inches \ndiameter) at the downstream wingwalls, left abutment, and upstream right road \nembankment; type-2 stone fill (less than 36 inches diameter) is at the upstream right \nwingwall. Additional details describing conditions at the site are included in the Level II \nSummary and Appendices D and E.
\nScour depths and rock rip-rap sizes were computed using the general guidelines described \nin Hydraulic Engineering Circular 18 (Richardson and others, 1993). Total scour at a \nhighway crossing is comprised of three components: 1) long-term streambed degradation; \n2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) \nand; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is \nthe sum of the three components. Equations are available to compute depths for contraction \nand local scour and a summary of the results of these computations follows.
\nContraction scour for all modelled flows ranged from 0.1 to 2.1 ft. with the worst-case \nscenario occurring at the 500-year discharge. Abutment scour ranged from 3.9 to 9.5 ft. The \nworst-case abutment scour also occurred at the 500-year discharge. Additional information \non scour depths and depths to armoring are included in the section titled “Scour Results”. \nScoured-streambed elevations, based on the calculated scour depths, are presented in tables \n1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour \ndepths were calculated assuming an infinite depth of erosive material and a homogeneous \nparticle-size distribution.
\nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1993, p. 48). Many factors, \nincluding historical performance during flood events, the geomorphic assessment, scour \nprotection measures, and the results of the hydraulic analyses, must be considered to \nproperly assess the validity of abutment scour results. Therefore, scour depths adopted by \nVTAOT may differ from the computed values documented herein, based on the \nconsideration of additional contributing factors and experienced engineering judgement.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr96239","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Olson, S.A., and Song, D.L., 1996, Level II scour analysis for Bridge 35 (BETHTH00190035) on Town Highway 19, crossing Gilead Brook, Bethel, Vermont: U.S. Geological Survey Open-File Report 96-239, iv, 30 p., https://doi.org/10.3133/ofr96239.","productDescription":"iv, 30 p.","numberOfPages":"35","costCenters":[],"links":[{"id":179182,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96239.GIF"},{"id":279389,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0239/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Bethel","otherGeospatial":"Gilead Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.75,43.875 ], [ -72.75,44.0 ], [ -72.625,44.0 ], [ -72.625,43.875 ], [ -72.75,43.875 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a6473","contributors":{"authors":[{"text":"Olson, Scott A. 0000-0002-1064-2125 solson@usgs.gov","orcid":"https://orcid.org/0000-0002-1064-2125","contributorId":2059,"corporation":false,"usgs":true,"family":"Olson","given":"Scott","email":"solson@usgs.gov","middleInitial":"A.","affiliations":[{"id":405,"text":"NH/VT office of New England Water Science Center","active":true,"usgs":true}],"preferred":true,"id":240270,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Song, Donald L.","contributorId":107335,"corporation":false,"usgs":true,"family":"Song","given":"Donald","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":240271,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49805,"text":"ofr96307 - 1996 - Level II scour analysis for Bridge 43 (BETHTH00070043) on Town Highway 07, crossing Gilead Brook, Bethel, Vermont","interactions":[],"lastModifiedDate":"2013-12-11T09:28:08","indexId":"ofr96307","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"96-307","title":"Level II scour analysis for Bridge 43 (BETHTH00070043) on Town Highway 07, crossing Gilead Brook, Bethel, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nBETHTH00070043 on town highway 7 crossing Gilead Brook, Bethel, Vermont (figures \n1–8). A Level II study is a basic engineering analysis of the site, including a quantitative \nanalysis of stream stability and scour (U.S. Department of Transportation, 1993). A Level \nI study is included in Appendix E of this report. A Level I study provides a qualitative \ngeomorphic characterization of the study site. Information on the bridge available from \nVTAOT files was compiled prior to conducting Level I and Level II analyses and can be \nfound in Appendix D.
\nThe site is in the Green Mountain physiographic province of central Vermont in the town of \nBethel. The 6.81-mi2\n drainage area is in a predominantly rural and forested basin. In the \nvicinity of the study site, the banks have dense woody vegetation coverage except for the \ndownstream right bank near the bridge, which is grass covered.
\nIn the study area, Gilead Brook has an incised, slightly sinuous channel with a slope of \napproximately 0.0181 ft/ft, an average channel top width of 36 ft and an average channel \ndepth of 4.0 ft. The predominant channel bed material is cobble (D50 is 79.6 mm or 0.261\nft). The geomorphic assessment at the time of the Level I and Level II site visit on October \n19, 1994, indicated that the reach was stable.
\nThe town highway 7 crossing of Gilead Brook is a 31-ft-long, two-lane bridge consisting of \none 27-foot concrete slab type superstructure (Vermont Agency of Transportation, written \ncommun., August 24, 1994). The bridge is supported by vertical, concrete abutments with \nwingwalls. The channel is skewed approximately 30 degrees to the opening while the \nopening-skew-to-roadway is 15 degrees.
\nA scour hole 0.5 ft deeper than the mean thalweg depth was observed at the right side of the \ndownstream bridge face during the Level I assessment. The scour protection measures in \nplace at the site were type-1 stone fill (less than 12 inches diameter) along the right \nabutment and both downstream banks, type-2 stone fill (less than 36 inches diameter) on all \nof the road approach embankments, both upstream banks, and along the entire base length \nof the wingwalls. Additional details describing conditions at the site are included in the \nLevel II Summary and Appendices D and E.
\nScour depths and rock rip-rap sizes were computed using the general guidelines described \nin Hydraulic Engineering Circular 18 (Richardson and others, 1995). Total scour at a \nhighway crossing is comprised of three components: 1) long-term streambed degradation; \n2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) \nand; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is \nthe sum of the three components. Equations are available to compute depths for contraction \nand local scour and a summary of the results of these computations follows.
\nContraction scour for all modelled flows ranged from 0.0 to 1.4 ft. The worst-case \ncontraction scour occurred at the incipient overtopping discharge, which was between the \n100- and 500-year discharges. Abutment scour ranged from 6.6 to 11.0 ft. with the worst-case scenario occurring at the 500-year discharge. Additional information on scour depths \nand depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. \nA cross-section of the scour computed at the bridge is presented in figure 8. Scour depths \nwere calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution.
\nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Many factors, \nincluding historical performance during flood events, the geomorphic assessment, scour \nprotection measures, and the results of the hydraulic analyses, must be considered to \nproperly assess the validity of abutment scour results. Therefore, scour depths adopted by \nVTAOT may differ from the computed values documented herein, based on the \nconsideration of additional contributing factors and experienced engineering judgement.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr96307","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Ivanoff, M.A., and Olson, S.A., 1996, Level II scour analysis for Bridge 43 (BETHTH00070043) on Town Highway 07, crossing Gilead Brook, Bethel, Vermont: U.S. Geological Survey Open-File Report 96-307, iv, 51 p., https://doi.org/10.3133/ofr96307.","productDescription":"iv, 51 p.","numberOfPages":"56","costCenters":[],"links":[{"id":179404,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96307.GIF"},{"id":279376,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0307/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Bethel","otherGeospatial":"Gilead Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.75,43.875 ], [ -72.75,44.0 ], [ -72.625,44.0 ], [ -72.625,43.875 ], [ -72.75,43.875 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a6121","contributors":{"authors":[{"text":"Ivanoff, Michael A.","contributorId":27105,"corporation":false,"usgs":true,"family":"Ivanoff","given":"Michael","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":240291,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Olson, Scott A. 0000-0002-1064-2125 solson@usgs.gov","orcid":"https://orcid.org/0000-0002-1064-2125","contributorId":2059,"corporation":false,"usgs":true,"family":"Olson","given":"Scott","email":"solson@usgs.gov","middleInitial":"A.","affiliations":[{"id":405,"text":"NH/VT office of New England Water Science Center","active":true,"usgs":true}],"preferred":true,"id":240290,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49789,"text":"ofr96231 - 1996 - Level II scour analysis for Bridge 25 (HARDTH00420025) on Town Highway 42, crossing Lamoille River, Hardwick, Vermont","interactions":[],"lastModifiedDate":"2013-12-11T12:59:53","indexId":"ofr96231","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"96-231","title":"Level II scour analysis for Bridge 25 (HARDTH00420025) on Town Highway 42, crossing Lamoille River, Hardwick, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nHARDTH00420025 on town highway 42 crossing the Lamoille River, Hardwick, Vermont \n(figures 1–8). A Level II study is a basic engineering analysis of the site, including a \nquantitative analysis of stream stability and scour (U.S. Department of Transportation, \n1993). A Level I study is included in Appendix E of this report. A Level I study provides \na qualitative geomorphic characterization of the study site. Information on the bridge \navailable from VTAOT files was compiled prior to conducting Level I and Level II \nanalyses and can be found in Appendix D.
\nThe site is in the Green Mountain physiographic division of north-central Vermont in the \ntown of Hardwick. The 119-mi2\n drainage area is in a predominantly rural basin. In the \nvicinity of the study site, the left banks are covered by pasture and (or) fields. The right \nbank of Lamoille River is adjacent to Vermont Route 15 near the north edge of the Lamoille \nRiver valley.
\nIn the study area, the Lamoille River has a sinuous channel with a slope of approximately \n0.0004 ft/ft, an average channel top width of 89.0 ft and an average channel depth of 8.0 ft. \nThe predominant channel bed material is sand and gravel (D50 is 22.4 mm or 0.0733 ft). In \ngeneral, the banks have sparse or no woody vegetative cover and the reach was noted to be \nlaterally unstable at the time of the Level I site visit on July 25, 1995. The Level II work \nwas completed on 07/27/95 and the site was revisited on August 16, 1995, just after the \nAugust 5-6, 1995 flood on the Lamoille River. Findings from this follow-up visit are \npresented in Appendix G.
\nThe town highway 42 crossing of the Lamoille Riveris a 62-ft-long, two-lane bridge \nconsisting of one 60-foot steel- beam span with a concrete deck, supported by vertical \nabutments with wingwalls on upstream and downstream sides (Vermont Agency of \nTransportation, written commun., August 24, 1994). The bridge is supported by vertical \nabutments with wingwalls on upstream and downstream sides. The channel is not skewed to \nthe opening and the opening-skew-to-roadway is 0 degrees.
\nA scour hole 3.0 ft deeper than the mean thalweg depth was observed 5 feet upstream from \nthe bridge face at mid-channel during the Level I assessment. Additional details describing \nconditions at the site are included in the Level II Summary and Appendices D and E.
\nScour depths and rock rip-rap sizes were computed using the general guidelines described \nin Hydraulic Engineering Circular 18 (Richardson and others, 1993).\nTotal scour at a highway crossing is comprised of three components: 1) long-term \naggradation or degradation; 2) contraction scour (due to reduction in flow area caused by a \nbridge) and; 3) local scour (caused by accelerated flow around piers and abutments). Total \nscour is the sum of the three components. Equations are available to compute scour depths \nfor contraction and local scour and a summary of the results follows.
\nContraction scour for all modelled flows was 0.0 ft. Abutment scour ranged from 6.5 ft to \n15.6 ft and the worst-case abutment scour occurred at the 500-year discharge. Scour depths \nand depths to armoring are summarized on p. 14 in the section titled “Scour Results”. \nScour elevations, based on the calculated depths are presented in tables 1 and 2; a graph of \nthe scour elevations is presented in figure 8 Scour depths were calculated assuming an \ninfinite depth of erosive material and a homogeneous particle-size distribution.
\nFor all scour presented in this report, “the scour depths adopted [by VTAOT] may differ \nfrom the equation values based on engineering judgement” (Richardson and others, 1993, p. \n21, 27). It is generally accepted that the Froehlich equation (abutment scour) gives \n“excessively conservative estimates of scour depths” (Richardson and others, 1993, p. 48). \nMany factors, including historical performance during flood events, the geomorphic \nassessment, and the results of the hydraulic analyses, must be considered to properly assess \nthe validity of abutment scour results.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr96231","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Ayotte, J., 1996, Level II scour analysis for Bridge 25 (HARDTH00420025) on Town Highway 42, crossing Lamoille River, Hardwick, Vermont: U.S. Geological Survey Open-File Report 96-231, iv, 31 p., https://doi.org/10.3133/ofr96231.","productDescription":"iv, 31 p.","numberOfPages":"36","costCenters":[],"links":[{"id":179107,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96231.GIF"},{"id":279394,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0231/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Hardwick","otherGeospatial":"Lamoille River","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.5,44.5 ], [ -72.5,44.625 ], [ -72.375,44.625 ], [ -72.375,44.5 ], [ -72.5,44.5 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b1ae4b07f02db6a8043","contributors":{"authors":[{"text":"Ayotte, Joseph D. jayotte@usgs.gov","contributorId":1802,"corporation":false,"usgs":true,"family":"Ayotte","given":"Joseph D.","email":"jayotte@usgs.gov","affiliations":[{"id":466,"text":"New England Water Science Center","active":true,"usgs":true}],"preferred":false,"id":240261,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":49785,"text":"ofr96195 - 1996 - Level II scour analysis for Bridge 27 (BRIDTH00490027) on Town Highway 049, crossing Broad Brook, Bridgewater, Vermont","interactions":[],"lastModifiedDate":"2013-12-06T15:01:48","indexId":"ofr96195","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"96-195","title":"Level II scour analysis for Bridge 27 (BRIDTH00490027) on Town Highway 049, crossing Broad Brook, Bridgewater, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nBRIDTH00490027 on town highway 49 crossing Broad Brook, Bridgewater, Vermont \n(figures 1–8). A Level II study is a basic engineering analysis of the site, including a \nquantitative analysis of stream stability and scour (U.S. Department of Transportation, \n1993). A Level I study is included in Appendix E of this report. A Level I study provides \na qualitative geomorphic characterization of the study site. Information on the bridge \navailable from VTAOT files was compiled prior to conducting Level I and Level II \nanalyses and can be found in Appendix D.\nThe site is in the Green Mountain physiographic province of central Vermont in the town of \nBridgewater. The 13.9-mi2 drainage area is in a predominantly rural and forested basin. In \nthe vicinity of the study site, the left and right banks are pasture with moderate tree cover on \nthe immediate banks. Upstream of bridge 27, a gravel road runs parallel to the left bank.\nIn the study area, the Broad Brook has an incised channel with a slope of approximately \n0.007 ft/ft, an average channel top width of 54 ft and an average channel depth of 4 ft. The \npredominant channel bed materials are gravel and cobble with a D50 (median diameter) \nof \n77.9 mm or 0.256 ft. The geomorphic assessment at the time of the Level I and Level II site \nvisit on November 9, 1994, indicated that the reach was stable.\nThe town highway 49 crossing of the Broad Brook is a 32-ft-long, one-lane bridge \nconsisting of one 31-ft steel-beam span (Vermont Agency of Transportation, written \ncommun., August 24, 1994). The bridge is supported by vertical, concrete abutments with \nwingwalls. The left abutment is noted as settled due to previous undermining. Type-2 (less \nthan 3 ft diameter) stone fill protects the upstream left and right wingwalls, the downstream \nright wingwall, the right abutment, the upstream right road embankment, and the \ndownstream left and right road embankments. Type-3 (less than 4 ft diameter) stone fill \nprotects the downstream left wingwall, but it’s condition was reported as slumping. The \nchannel is skewed approximately 10 degrees to the opening; the opening-skew-to-roadway \nis also 10 degrees. Additional details describing conditions at the site are included in the \nLevel II Summary and Appendices D and E.\nScour depths and rock rip-rap sizes were computed using the general guidelines described \nin Hydraulic Engineering Circular 18 (Richardson and others, 1993). Scour depths were \ncalculated assuming an infinite depth of erosive material and a homogeneous particle-size \ndistribution. The scour analysis results are presented in tables 1 and 2 and a graph of the \nscour depths is presented in figure 8.","language":"English","publisher":"U.S. Geological Survey","doi":"10.3133/ofr96195","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Olson, S.A., 1996, Level II scour analysis for Bridge 27 (BRIDTH00490027) on Town Highway 049, crossing Broad Brook, Bridgewater, Vermont: U.S. Geological Survey Open-File Report 96-195, iv, 30 p., https://doi.org/10.3133/ofr96195.","productDescription":"iv, 30 p.","numberOfPages":"35","costCenters":[],"links":[{"id":178610,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96195.png"},{"id":279410,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0195/report.pdf"}],"country":"United States","state":"Vermont","city":"Bridgewater","otherGeospatial":"Broad Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.758005,43.558839 ], [ -72.758005,43.694051 ], [ -72.577733,43.694051 ], [ -72.577733,43.558839 ], [ -72.758005,43.558839 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b1ae4b07f02db6a7fcd","contributors":{"authors":[{"text":"Olson, Scott A. 0000-0002-1064-2125 solson@usgs.gov","orcid":"https://orcid.org/0000-0002-1064-2125","contributorId":2059,"corporation":false,"usgs":true,"family":"Olson","given":"Scott","email":"solson@usgs.gov","middleInitial":"A.","affiliations":[{"id":405,"text":"NH/VT office of New England Water Science Center","active":true,"usgs":true}],"preferred":true,"id":240256,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":49804,"text":"ofr96306 - 1996 - Level II scour analysis for Bridge 35 (BRNATH00680035) on Town Highway 68, crossing Locust Creek, Barnard, Vermont","interactions":[],"lastModifiedDate":"2013-12-11T09:51:51","indexId":"ofr96306","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1996","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"96-306","title":"Level II scour analysis for Bridge 35 (BRNATH00680035) on Town Highway 68, crossing Locust Creek, Barnard, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nBRNATH00680035 on town highway 68 crossing Locust Creek, Barnard, Vermont \n(figures 1–8). A Level II study is a basic engineering analysis of the site, including a \nquantitative analysis of stream stability and scour (U.S. Department of Transportation, \n1993). A Level I study is included in Appendix E of this report. A Level I study provides \na qualitative geomorphic characterization of the study site. Information on the bridge \navailable from VTAOT files was compiled prior to conducting Level I and Level II \nanalyses and can be found in Appendix D.
\nThe site is in the Green Mountain physiographic province of central Vermont in the town of \nBarnard. The 24.1-mi2\n drainage area is in a predominantly rural and forested basin. In the \nvicinity of the study site, the banks have woody vegetation coverage.
\nIn the study area, Locust Creek has an incised sinuous channel with a slope of \napproximately 0.0133 ft/ft, an average channel top width of 58 ft and an average channel \ndepth of 5 ft. The predominant channel bed material is cobble (D50 is 135 mm or 0.443 ft). \nThe geomorphic assessment at the time of the Level I and Level II site visits on September \n21 and 27, respectively, with a check on December 15, 1994, indicated that the reach was \nstable.
\nThe town highway 68 crossing of Locust Creek is a 30-ft-long, one-lane bridge consisting \nof one 28-foot concrete slab type superstructure (Vermont Agency of Transportation, \nwritten commun., August 23, 1994). The bridge is supported by vertical, concrete\nabutments with wingwalls. The channel is not skewed to the opening and the opening-skew-to-roadway is zero degrees.
\nA scour hole 0.5 ft deeper than the mean thalweg depth was observed along the right \nabutment and downstream right wingwall during the Level I assessment. The only scour \nprotection measure in place at the site was type-2 stone fill (less than 36 inches diameter) at \nthe left abutment and wingwalls except the downstream right wingwall. Additional details \ndescribing conditions at the site are included in the Level II Summary and Appendices D.
\nScour depths and rock rip-rap sizes were computed using the general guidelines described \nin Hydraulic Engineering Circular 18 (Richardson and others, 1993). Total scour at a \nhighway crossing is comprised of three components: 1) long-term streambed degradation; \n2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) \nand; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is \nthe sum of the three components. Equations are available to compute depths for contraction \nand local scour and a summary of the results of these computations follows.
\nContraction scour for all modelled flows ranged from 0.0 to 3.4 ft. The worst-case \ncontraction scour occurred at the incipient overtopping discharge, which was between the \n100- and 500-year discharges. Abutment scour ranged from 11.5 to 25.7 ft. with the worst-case scenario occurring at the 500-year discharge. Additional information on scour depths \nand depths to armoring are included in the section titled \"Scour Results\". Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. \nA cross-section of the scour computed at the bridge is presented in figure 8. Scour depths \nwere calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution.
\nIt is generally accepted that the Froehlich equation (abutment scour) gives \"excessively \nconservative estimates of scour depths\" (Richardson and others, 1993, p. 48). Many factors, \nincluding historical performance during flood events, the geomorphic assessment, scour \nprotection measures, and the results of the hydraulic analyses, must be considered to \nproperly assess the validity of abutment scour results. Therefore, scour depths adopted by \nVTAOT may differ from the computed values documented herein, based on the \nconsideration of additional contributing factors and experienced engineering judgement.\nand E.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr96306","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Ivanoff, M.A., and Weber, M.A., 1996, Level II scour analysis for Bridge 35 (BRNATH00680035) on Town Highway 68, crossing Locust Creek, Barnard, Vermont: U.S. Geological Survey Open-File Report 96-306, iv, 30 p., https://doi.org/10.3133/ofr96306.","productDescription":"iv, 30 p.","numberOfPages":"35","costCenters":[],"links":[{"id":179403,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr96306.GIF"},{"id":279377,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1996/0306/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Barnard","otherGeospatial":"Locust Creek","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.75,43.75 ], [ -72.75,43.875 ], [ -72.625,43.875 ], [ -72.625,43.75 ], [ -72.75,43.75 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a64ab","contributors":{"authors":[{"text":"Ivanoff, Michael A.","contributorId":27105,"corporation":false,"usgs":true,"family":"Ivanoff","given":"Michael","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":240288,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Weber, Matthew A.","contributorId":41483,"corporation":false,"usgs":true,"family":"Weber","given":"Matthew","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":240289,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ]}