A database on a number of elements in oceanic volcanic rocks is presented, including the principal major-element oxides-SiO2, TiO2, Al2O3, Fe2O3(T), MnO, MgO, CaO, Na2O, K2O, and P2O5 (where T refers to total iron)–and the trace elements–Ba, Ce, Cr, Cu, Ni, Sc, Sr, V, Pb (mainly by isotope dilution), Yb, Zn, and Zr. Interpretations are given for transition metals, with emphasis on Mn, Sc, and V, in order to determine the concentration of the elements in primitive melts and assess their trends in magmatic differentiation. Transition metals are not enriched in plagioclase, so all are incompatible with pure plagioclase removal–that is, they become enriched in the melt. Both Cr and Ni are known to be highly compatible with olivine separation-i.e., they are depleted in the melt early in differentiation. Also, Sc is compatible with clinopyroxene (Cpx) removal from the melt and is depleted by separation of Cpx. Copper does not fit well in any of the principal silicates, but Cu, like Ni, is greatly enriched in sulfides that may remain in the source or separate from the magma. Decreasing Ni abundances and increasing Cu contents during differentiation are a sign of olivine separation. In the analysis presented herein, V–in the absence of Cpx separation–is found to behave remarkably like the moderately incompatible element Zn, and these two elements add to the list of element pairs of similar incompatibility whose ratios are insensitive to differentiation and to submarine weathering as well. Both are enhanced in titanomagnetite, so both would be compatible during titanomagnetite separation. When Cpx separates, however, V becomes compatible like Sc, but Zn remains incompatible. Thus, decreasing V (and Sc) contents and increasing Zn contents during differentiation are a sign of Cpx separation. Manganese often behaves much like Zn and therefore is moderately incompatible, but Mn is less compatible than Zn and V in titanomagnetite. Thus, decreasing Zn and V with increasing Mn is an indication of titanomagnetite removal. Dual compatible and incompatible trends with differentiation are found chiefly for Cu, Sc, and Sr. Distinguishing mid-ocean ridge basalts (MORB), oceanic-island volcanic rocks (OIV), and island-arc volcanic rocks (IAV) may be accomplished by plots of Ce/Yb versus Ba/Ce, where OIV plot to higher values of Ce/Yb than do MORB, and IAV data plot to higher values of Ba/Ce than do those of MORB. These ratios do not seem to be significantly affected by submarine weathering.
Infiltration and dispersion (including molecular diffusion) can transport volatile organic compounds (VOCs) from urban air into shallow groundwater. The gasoline additive methyl-tert-butyl ether (MTBE) is of special interest because of its (1) current levels in some urban air, (2) strong partitioning from air into water, (3) resistance to degradation, (4) use as an octane-booster since the 1970s, (5) rapidly increasing use in the 1990s to reduce CO and O3 in urban air, and (6) its frequent detection at low microgram per liter levels in shallow urban groundwater in Denver, New England, and elsewhere. Numerical simulations were conducted using a 1-D model domain set in medium sand (depth to water table = 5 m) to provide a test of whether MTBE and other atmospheric VOCs could move to shallow groundwater within the 10−15 y time frame over which MTBE has now been used in large amounts. Degradation and sorption were assumed negligible. In case 1 (no infiltration, steady atmospheric source), 10 y was not long enough to permit significant VOC movement by diffusion into shallow groundwater. Case 2 considered a steady atmospheric source plus 36 cm/y of net infiltration; groundwater at 2 m below the water table became nearly saturated with atmospheric levels of VOC within 5 y. Case 3 was similar to case 2, but considered the source to be seasonal, being “on” for only 5 of 12 months each year, as with the use of MTBE during the winter fuel-oxygenate season; groundwater at 2 m below the water table became equilibrated with 5/12 of the “source-on” concentration within 5 y. Cases 4 and 5 added an evapotranspiration (ET) loss of 36 cm/y, resulting in no net recharge. Case 4 took the ET from the surface, and case 5 took the ET from the capillary fringe at a depth of 3.5 m. Net VOC mass transfer to shallow groundwater after 5 y was less for both cases 4 and 5 than for case 3. However, it was significantly greater for cases 4 and 5 than for case 1, even though cases 1, 4, and 5 were all no-net recharge cases. The mechanism responsible for this effect was the dispersion acting on each downward infiltration event, and also on the ET-induced flow. The ability of MTBE to reach groundwater in cases 2−5 is taken as evidence of the potential importance of urban air as a non-point source for VOCs in shallow urban groundwater. Two subcases were run for both case 4 and case 5: subcase a (water and VOCs move with ET) and subcase b (water only moves with ET).
","language":"English","publisher":"ACS Publication","doi":"10.1021/es970040b","usgsCitation":"Pankow, J.F., Thomson, N., Johnson, R.L., Baehr, A.L., and Zogorski, J., 1997, The urban atmosphere as a non-point source for the transport of MTBE and other volatile organic compounds (VOCS) to shallow groundwater: Environmental Science & Technology, v. 31, no. 10, p. 2821-2828, https://doi.org/10.1021/es970040b.","productDescription":"8 p.","startPage":"2821","endPage":"2828","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":226344,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"31","issue":"10","noUsgsAuthors":false,"publicationDate":"1997-09-30","publicationStatus":"PW","scienceBaseUri":"505bb155e4b08c986b3252d9","contributors":{"authors":[{"text":"Pankow, J. F.","contributorId":20917,"corporation":false,"usgs":true,"family":"Pankow","given":"J.","email":"","middleInitial":"F.","affiliations":[],"preferred":false,"id":382985,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Thomson, N.R.","contributorId":51027,"corporation":false,"usgs":true,"family":"Thomson","given":"N.R.","email":"","affiliations":[],"preferred":false,"id":382987,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Johnson, Richard L.","contributorId":169575,"corporation":false,"usgs":false,"family":"Johnson","given":"Richard","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":382986,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Baehr, A. L.","contributorId":59831,"corporation":false,"usgs":true,"family":"Baehr","given":"A.","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":382988,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Zogorski, J.S.","contributorId":108201,"corporation":false,"usgs":true,"family":"Zogorski","given":"J.S.","email":"","affiliations":[],"preferred":false,"id":382989,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}} ,{"id":70246337,"text":"70246337 - 1997 - Precambrian to modern manganese mineralization: Changes in ore type and depositional environment","interactions":[],"lastModifiedDate":"2023-07-06T10:52:09.888642","indexId":"70246337","displayToPublicDate":"1996-12-03T11:54:24","publicationYear":"1997","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1791,"text":"Geological Society, London, Special Publications","active":true,"publicationSubtype":{"id":10}},"title":"Precambrian to modern manganese mineralization: Changes in ore type and depositional environment","docAbstract":"No abstract available.
","language":"English","publisher":"Geological Society of London","doi":"10.1144/GSL.SP.1997.119.01.01","usgsCitation":"Nicholson, K., Hein, J.R., Buhn, B., and Dasgupta, S., 1997, Precambrian to modern manganese mineralization: Changes in ore type and depositional environment: Geological Society, London, Special Publications, v. 119, p. 1-3, https://doi.org/10.1144/GSL.SP.1997.119.01.01.","productDescription":"3 p.","startPage":"1","endPage":"3","costCenters":[{"id":520,"text":"Pacific Coastal and Marine Science Center","active":true,"usgs":true}],"links":[{"id":418693,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"119","noUsgsAuthors":false,"publicationDate":"1996-12-03","publicationStatus":"PW","contributors":{"authors":[{"text":"Nicholson, Keith","contributorId":315564,"corporation":false,"usgs":false,"family":"Nicholson","given":"Keith","email":"","affiliations":[],"preferred":false,"id":876898,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Hein, James R. 0000-0002-5321-899X jhein@usgs.gov","orcid":"https://orcid.org/0000-0002-5321-899X","contributorId":140835,"corporation":false,"usgs":true,"family":"Hein","given":"James","email":"jhein@usgs.gov","middleInitial":"R.","affiliations":[{"id":520,"text":"Pacific Coastal and Marine Science Center","active":true,"usgs":true}],"preferred":true,"id":876899,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Buhn, Bernhard","contributorId":315565,"corporation":false,"usgs":false,"family":"Buhn","given":"Bernhard","email":"","affiliations":[],"preferred":false,"id":876900,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Dasgupta, Somnath","contributorId":315566,"corporation":false,"usgs":false,"family":"Dasgupta","given":"Somnath","email":"","affiliations":[],"preferred":false,"id":876901,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":24930,"text":"ofr95802 - 1997 - Preliminary geologic map of the Fillmore 7.5' quadrangle, Southern California: A digital database","interactions":[],"lastModifiedDate":"2023-06-07T18:58:47.929488","indexId":"ofr95802","displayToPublicDate":"1996-06-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"95-802","title":"Preliminary geologic map of the Fillmore 7.5' quadrangle, Southern California: A digital database","docAbstract":"This Open-File report is a digital geologic map database. This pamphlet serves to introduce and describe the digital data. There is no paper map included in the Open-File report.
\nThis digital map database is compiled from previously published sources combined with some new mapping and modifications in nomenclature. The geologic map database delineates map units that are identified by general age and lithology following the stratigraphic nomenclature of the U. S. Geological Survey. For detailed descriptions of the units, their stratigraphic relations, sources of geologic mapping, and data on exploratory wells consult Yerkes and Campbell (1995), and Yerkes and Showalter (1990). More specific information about the units may be available in the original sources.
","language":"English","publisher":"U.S. Geological Survey","doi":"10.3133/ofr95802","issn":"0094-9140","usgsCitation":"Yerkes, R., and Campbell, R.H., 1997, Preliminary geologic map of the Fillmore 7.5' quadrangle, Southern California: A digital database: U.S. Geological Survey Open-File Report 95-802, Readme: PDF, 11 p.; Readme: TXT; All database files; Geology; Structure; Wells; Composite base map, https://doi.org/10.3133/ofr95802.","productDescription":"Readme: PDF, 11 p.; Readme: TXT; All database files; Geology; Structure; Wells; Composite base map","numberOfPages":"11","additionalOnlineFiles":"Y","costCenters":[{"id":312,"text":"Geology, Minerals, Energy, and Geophysics Science Center","active":true,"usgs":true}],"links":[{"id":284127,"rank":7,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr95802.jpg"},{"id":284125,"rank":1,"type":{"id":7,"text":"Companion Files"},"url":"https://pubs.usgs.gov/of/1995/0802/fl-topo.e00.gz"},{"id":284124,"rank":2,"type":{"id":7,"text":"Companion Files"},"url":"https://pubs.usgs.gov/of/1995/0802/fl-wells.e00.gz"},{"id":284123,"rank":3,"type":{"id":7,"text":"Companion Files"},"url":"https://pubs.usgs.gov/of/1995/0802/fl-strc.e00.gz"},{"id":284120,"rank":6,"type":{"id":20,"text":"Read Me"},"url":"https://pubs.usgs.gov/of/1995/0802/pdf/of95-802.pdf"},{"id":284122,"rank":4,"type":{"id":7,"text":"Companion Files"},"url":"https://pubs.usgs.gov/of/1995/0802/fl-geol.e00.gz"},{"id":284121,"rank":5,"type":{"id":7,"text":"Companion Files"},"url":"https://pubs.usgs.gov/of/1995/0802/fill.tar.gz"},{"id":7655,"rank":8,"type":{"id":15,"text":"Index Page"},"url":"https://pubs.usgs.gov/of/1995/0802/","linkFileType":{"id":5,"text":"html"}}],"country":"United States","state":"California","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -119.0,34.375 ], [ -119.0,34.5 ], [ -118.875,34.5 ], [ -118.875,34.375 ], [ -119.0,34.375 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b02e4b07f02db698aa9","contributors":{"authors":[{"text":"Yerkes, R.F.","contributorId":105752,"corporation":false,"usgs":true,"family":"Yerkes","given":"R.F.","affiliations":[],"preferred":false,"id":192820,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Campbell, R. H.","contributorId":52160,"corporation":false,"usgs":true,"family":"Campbell","given":"R.","email":"","middleInitial":"H.","affiliations":[],"preferred":false,"id":192819,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":50037,"text":"ofr97819 - 1997 - Level II scour analysis for Bridge 29 (ROYATH00920029) on Town Highway 92, crossing the First Branch White River, Royalton, Vermont","interactions":[],"lastModifiedDate":"2016-08-25T15:13:22","indexId":"ofr97819","displayToPublicDate":"1994-01-01T07:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-819","title":"Level II scour analysis for Bridge 29 (ROYATH00920029) on Town Highway 92, crossing the First Branch White River, Royalton, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure ROYATH00920029 on Town Highway 92 crossing the First Branch White River, Royalton, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including a quantitative analysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of a Level I scour investigation also are included in Appendix E of this report. A Level I investigation provides a qualitative geomorphic characterization of the study site. Information on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is found in Appendix D.
The site is in the New England Upland section of the New England physiographic province in central Vermont. The 101-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is pasture upstream and downstream of the bridge.
In the study area, the First Branch White River has an incised, sinuous channel with a slope of approximately 0.001 ft/ft, an average channel top width of 81 ft and an average bank height of 9 ft. The channel bed material ranges from sand to bedrock with a median grain size (D50) of 1.18 mm (0.00347 ft). The geomorphic assessment at the time of the Level I site visit on July 23, 1996 and Level II site visit on June 2, 1995, indicated that the reach was stable.
The Town Highway 92 crossing of the First Branch White River is a 59-ft-long, one-lane bridge consisting of a 57-foot steel-stringer span (Vermont Agency of Transportation, written communication, March 23, 1995). The opening length of the structure parallel to the bridge face is 52.2 ft. The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 20 degrees to the opening while the opening-skew-to-roadway is zero degrees.
A scour hole 4.0 ft deeper than the mean thalweg depth was observed in the upstream channel during the Level I assessment. The only scour protection measure at the site was type-2 stone fill (less than 36 inches diameter) along the upstream left and right wingwalls, the left abutment and downstream left wingwall. Additional details describing conditions at the site are included in the Level II Summary and Appendices D and E.
Scour depths and recommended rock rip-rap sizes were computed using the general guidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995) for the 100- and 500-year discharges. In addition, the incipient roadway-overtopping discharge was determined and analyzed as another potential worst-case scour scenario. Total scour at a highway crossing is comprised of three components: 1) long-term streambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is the sum of the three components. Equations are available to compute depths for contraction and local scour and a summary of the results of these computations follows.
Contraction scour for all modelled flows ranged from 0.0 to 4.1 ft. The worst-case contraction scour occurred at the incipient roadway-overtopping discharge, which was less than the 100-year discharge. Left abutment scour ranged from 12.9 to 15.4 ft, where the worst-case abutment scour occurred at the 500-year discharge. Right abutment scour ranged from 14.5 to 15.0 ft, where 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 scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution.
It is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, computed scour depths are evaluated in combination with other information including (but not limited to) historical performance during flood events, the geomorphic stability assessment, existing scour protection measures, and the results of the hydraulic analyses. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr97819","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Wild, E.C., and Hammond, R.E., 1997, Level II scour analysis for Bridge 29 (ROYATH00920029) on Town Highway 92, crossing the First Branch White River, Royalton, Vermont: U.S. Geological Survey Open-File Report 97-819, iv, 50 p., https://doi.org/10.3133/ofr97819.","productDescription":"iv, 50 p.","numberOfPages":"54","costCenters":[],"links":[{"id":175955,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97819.PNG"},{"id":279647,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0819/report.pdf"}],"country":"United States","state":"Vermont","city":"Royalton","otherGeospatial":"First Branch White River","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.64516,43.756585 ], [ -72.64516,43.873348 ], [ -72.460132,43.873348 ], [ -72.460132,43.756585 ], [ -72.64516,43.756585 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b19e4b07f02db6a7efb","contributors":{"authors":[{"text":"Wild, Emily C. 0000-0001-6157-7629 ecwild@usgs.gov","orcid":"https://orcid.org/0000-0001-6157-7629","contributorId":1810,"corporation":false,"usgs":true,"family":"Wild","given":"Emily","email":"ecwild@usgs.gov","middleInitial":"C.","affiliations":[{"id":5081,"text":"Libraries","active":false,"usgs":true}],"preferred":false,"id":240678,"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":240679,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49868,"text":"ofr974 - 1997 - Level II scour analysis for Bridge 6 (BRISVT01160006) on State Highway 116, crossing Little Notch Brook, Bristol, Vermont","interactions":[],"lastModifiedDate":"2013-12-20T15:26:50","indexId":"ofr974","displayToPublicDate":"1994-01-01T07:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-4","title":"Level II scour analysis for Bridge 6 (BRISVT01160006) on State Highway 116, crossing Little Notch Brook, Bristol, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nBRISVT01160006 on State Route 116 crossing the Little Notch Brook, Bristol, Vermont \n(figures 1–8). A Level II study is a basic engineering analysis of the site, including a \nquantitative analysis of stream stability and scour (U.S. Department of Transportation, \n1993). Results of a Level I scour investigation also are included in Appendix E of this \nreport. A Level I investigation provides a qualitative geomorphic characterization of the \nstudy site. Information on the bridge, gleaned from Vermont Agency of Transportation \n(VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is \nfound in Appendix D.\nThe site is in the Green Mountain section of the New England physiographic province of \nWest-central Vermont in the town of Bristol. The 8.59-mi2\n drainage area is in a \npredominantly rural and forested basin. In the vicinity of the study site, the surface cover is \ndense forest except for the downstream left side, which is row crops. \nIn the study area, Little Notch Brook has a sinuous channel with a slope of approximately \n0.005 ft/ft, an average channel top width of 32 ft and an average channel depth of 4 ft. The \npredominant channel bed material is sand and gravel with a median grain size (D50\n) of 17.4 \nmm (0.0570 ft). The geomorphic assessment at the time of the Level I and Level II site visit \non June 13, 1996, indicated that the reach was laterally unstable. The sinuous configuration \nof the channel with fine bed and bank material, a sharp channel bend upstream, and point \nbars and cut-banks upstream and downstream of this site are among the primary \ncharacteristics, which suggest lateral instability. \nIn addition, there is evidence of streambed degradation at this site. A large eddy was noted \nat the location where Little Notch Brook enters the New Haven River about 100 feet \ndownstream. There was a large scour hole noted at the location of the eddy, which is likely \nto remove streambed material at least as quickly as supplied from upstream on Little Notch \nBrook. Hence, channel degradation may be significant during a flood event.\nThe state route 116 crossing of Little Notch Brook is a 24-ft-long, two-lane bridge \nconsisting of one 21-foot concrete span (Vermont Agency of Transportation, written \ncommunication, December 14, 1995). The bridge is supported by vertical, concrete \nabutments with wingwalls. The channel is skewed approximately 15 degrees to the opening \nwhile the opening-skew-to-roadway is 25 degrees. \nThere was one foot of scour evident along the downstream half of the left abutment footing \nand some separation of the left abutment wall from the deck above due to settling. The left \nabutment footing was undermined up to a foot at the downstream end. The scour protection \nmeasures at the site were type-1 stone fill (less than 12 inches diameter) on the upstream left \nbank and type-2 stone fill (less than 36 inches diameter) on the right banks and right \nwingwalls upstream and downstream of the structure. Additional details describing \nconditions at the site are included in the Level II Summary and Appendices D and E.\nScour depths and rock rip-rap sizes were computed using the general guidelines described \nin Hydraulic Engineering Circular 18 (Richardson and others, 1995). Total scour at a \nhighway crossing is comprised of three components: 1) long-term streambed degradation; \n2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) \nand; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is \nthe sum of the three components. Equations are available to compute depths for contraction \nand local scour and a summary of the results of these computations follows.\nContraction scour for all modelled flows ranged from 3.2 to 4.3 ft. The worst-case \ncontraction scour occurred at the 500-year discharge. Abutment scour ranged from 6.0 to \n10.0 ft. The worst-case abutment scour occurred at the 500-year discharge. Additional \ninformation on scour depths and depths to armoring are included in the section titled “Scour \nResults”. Scoured-streambed elevations, based on the calculated scour depths, are presented \nin tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure \n8. Scour depths were calculated assuming an infinite depth of erosive material and a \nhomogeneous particle-size distribution. \nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr974","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Boehmler, E.M., and Burns, R.L., 1997, Level II scour analysis for Bridge 6 (BRISVT01160006) on State Highway 116, crossing Little Notch Brook, Bristol, Vermont: U.S. Geological Survey Open-File Report 97-4, iv, 53 p., https://doi.org/10.3133/ofr974.","productDescription":"iv, 53 p.","numberOfPages":"57","costCenters":[],"links":[{"id":169560,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr974.PNG"},{"id":279832,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0004/report.pdf"}],"country":"United States","state":"Vermont","city":"Bristol","otherGeospatial":"Little Notch Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -73.149505,44.040797 ], [ -73.149505,44.192184 ], [ -73.0158,44.192184 ], [ -73.0158,44.040797 ], [ -73.149505,44.040797 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a5a25","contributors":{"authors":[{"text":"Boehmler, Erick M.","contributorId":96303,"corporation":false,"usgs":true,"family":"Boehmler","given":"Erick","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":240390,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Burns, Ronda L.","contributorId":71602,"corporation":false,"usgs":true,"family":"Burns","given":"Ronda","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":240389,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":50033,"text":"ofr97815 - 1997 - Level II scour analysis for Bridge 37, (BRNETH00740037) on Town Highway 74, crossing South Peacham Brook, Barnet, Vermont","interactions":[],"lastModifiedDate":"2013-12-20T11:48:32","indexId":"ofr97815","displayToPublicDate":"1994-01-01T07:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-815","title":"Level II scour analysis for Bridge 37, (BRNETH00740037) on Town Highway 74, crossing South Peacham Brook, Barnet, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nBRNETH00740037 on Town Highway 74 crossing South Peacham Brook, Barnet, \nVermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including \na quantitative analysis of stream stability and scour (U.S. Department of Transportation, \n1993). Results of a Level I scour investigation also are included in Appendix E of this \nreport. A Level I investigation provides a qualitative geomorphic characterization of the \nstudy site. Information on the bridge, gleaned from Vermont Agency of Transportation \n(VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is \nfound in Appendix D.\nThe site is in the New England Upland section of the New England physiographic province \nin northeastern Vermont. The 12.1-mi2\n drainage area is in a predominantly rural and \nforested basin. In the vicinity of the study site, the surface cover is pasture upstream of the \nbridge and on the downstream left bank while the immediate banks have sparse shrubs and \ntrees. Downstream of the bridge, the surface cover is shrub and brushland.\nIn the study area, South Peacham Brook has an incised, sinuous channel with a slope of \napproximately 0.004 ft/ft, an average channel top width of 33 ft and an average bank height \nof 3 ft. The channel bed material ranges from sand to cobble with a median grain size (D50)\nof 0.914 mm (0.003 ft). The geomorphic assessment at the time of the Level I and Level II \nsite visit on August 24, 1995, indicated that the reach was laterally unstable. There are cutbanks upstream and downstream of the bridge.\nThe Town Highway 74 crossing of South Peacham Brook is a 30-ft-long, two-lane bridge \nconsisting of one 28-foot concrete slab span (Vermont Agency of Transportation, written \ncommunication, March 16, 1995). The opening length of the structure parallel to the bridge \nface is 25.7 ft. The bridge is supported by vertical, concrete abutments with wingwalls. The \nchannel is skewed approximately 30 degrees to the opening while the computed openingskew-to-roadway is 5 degrees.\nA channel scour hole 2.0 ft deeper than the mean thalweg depth was observed at the \nupstream bridge face, along the upstream right wingwall protection, during the Level I \nassessment. The scour protection measures at the site included type-1 stone fill (less than 12 \ninches diameter) along the downstream left and right wingwalls, downstream banks, and at \nthe downstream end of the left and right abutments. There is also type-2 stone fill (less than \n36 inches diameter) along the upstream right bank and upstream right wingwall. Additional \ndetails describing conditions at the site are included in the Level II Summary and \nAppendices D \nand E.\nScour depths and recommended rock rip-rap sizes were computed using the general \nguidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995) \nfor the 100- and 500-year discharges. In addition, the incipient roadway-overtopping \ndischarge was determined and analyzed as another potential worst-case scour scenario. \nTotal scour at a highway crossing is comprised of three components: 1) long-term \nstreambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction \nin flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and \nabutments). Total scour is the sum of the three components. Equations are available to \ncompute depths for contraction and local scour and a summary of the results of these \ncomputations follows.\nContraction scour for all modelled flows ranged from 15.8 to 22.5 ft. The worst-case \ncontraction scour occurred at the 500-year discharge. Abutment scour ranged from 6.7 to \n11.1 ft. The worst-case abutment scour also occurred at the 500-year discharge. Additional \ninformation on scour depths and depths to armoring are included in the section titled “Scour \nResults”. Scoured-streambed elevations, based on the calculated scour depths, are presented \nin Tables 1 and 2. A cross-section of the scour computed at the bridge is presented in Figure \n8. Scour depths were calculated assuming an infinite depth of erosive material and a \nhomogeneous particle-size distribution. \nUsually, computed scour depths are evaluated in combination with other information \nincluding (but not limited to) historical performance during flood events, the geomorphic \nstability assessment, existing scour protection measures, and the results of the hydraulic \nanalyses. Therefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr97815","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Burns, R.L., and Severance, T., 1997, Level II scour analysis for Bridge 37, (BRNETH00740037) on Town Highway 74, crossing South Peacham Brook, Barnet, Vermont: U.S. Geological Survey Open-File Report 97-815, iv, 50 p., https://doi.org/10.3133/ofr97815.","productDescription":"iv, 50 p.","numberOfPages":"54","costCenters":[],"links":[{"id":162212,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97815.PNG"},{"id":279651,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0815/report.pdf"}],"country":"United States","state":"Vermont","city":"Barnet","otherGeospatial":"South Peacham Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.187815,44.255718 ], [ -72.187815,44.398356 ], [ -71.984617,44.398356 ], [ -71.984617,44.255718 ], [ -72.187815,44.255718 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a62ca","contributors":{"authors":[{"text":"Burns, Ronda L.","contributorId":71602,"corporation":false,"usgs":true,"family":"Burns","given":"Ronda","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":240671,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Severance, Timothy","contributorId":104927,"corporation":false,"usgs":true,"family":"Severance","given":"Timothy","email":"","affiliations":[],"preferred":false,"id":240672,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49945,"text":"ofr97397 - 1997 - Level II scour analysis for Bridge 6 (ALBUTH00150006) on Town Highway 15, crossing Mud Creek, Alburg, Vermont","interactions":[],"lastModifiedDate":"2013-12-19T12:59:01","indexId":"ofr97397","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-397","title":"Level II scour analysis for Bridge 6 (ALBUTH00150006) on Town Highway 15, crossing Mud Creek, Alburg, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nALBUTH00150006 on Town Highway 15 crossing Mud Creek, Alburg, Vermont (figures \n1–8). A Level II study is a basic engineering analysis of the site, including a quantitative \nanalysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of \na Level I scour investigation also are included in Appendix E of this report. A Level I \ninvestigation provides a qualitative geomorphic characterization of the study site. \nInformation on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) \nfiles, was compiled prior to conducting Level I and Level II analyses and is found in \nAppendix D.\nThe site is in the Champlain section of the St. Lawrence Valley physiographic province in \nnorthwestern Vermont. The 2.90-mi2\n drainage area is in a predominantly rural and forested \nbasin. However, nearly a third of the drainage, including the location of the study site, is \nwetland.\nIn the study area, Mud Creek has an sinuous channel through wetland with a slope of \napproximately 0.0002 ft/ft, an average channel top width of 42 ft and an average bank \nheight of 2 ft. The channel bed material ranges from clay to sand with an estimated median \ngrain size (D50) of 0.047 mm (0.00015 ft). The geomorphic assessment at the time of the \nLevel I and Level II site visit on June 26, 1995, indicated that the reach was stable.\nThe Town Highway 15 crossing of Mud Creek is a 30-ft-long, one-lane bridge consisting of \none 28-foot steel-beam span (Vermont Agency of Transportation, written communication, \nMarch 7, 1995). The opening length of the structure parallel to the bridge face is 26.7 ft. \nThe bridge is supported by vertical, concrete abutments with wingwalls. The channel is \nskewed zero degrees to the opening and the opening-skew-to-roadway is also zero degrees. \nChannel scour, approximately 2 ft deeper than the mean thalweg depth, was observed in the \nmiddle of the channel extending from 5 to 35 ft upstream of the bridge. The only scour \ncountermeasure observed at this site was some small stone, possibly type-1 stone fill (less \nthan 12 inches diameter), partially covering the channel bed under the bridge. Additional \ndetails describing conditions at the site are included in the Level II Summary and \nAppendices D and E.\nScour depths and recommended rock rip-rap sizes were computed using the general \nguidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995). \nTotal scour at a highway crossing is comprised of three components: 1) long-term \nstreambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction \nin flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and \nabutments). Total scour is the sum of the three components. Equations are available to \ncompute depths for contraction and local scour and a summary of the results of these \ncomputations follows.\nContraction scour for all modelled flows ranged from 6.2 to 7.2 ft. The worst-case \ncontraction scour occurred at the 500-year discharge. Abutment scour ranged from 2.0 to \n2.4 ft and 2.1 to 2.6 ft on the left and right abutments respectively. The worst-case abutment \nscour occurred at the 500-year discharge. Additional information on scour depths and \ndepths to armoring are included in the section titled “Scour Results”. Scoured-streambed \nelevations, based on the calculated scour depths, are presented in tables 1 and 2. A crosssection of the scour computed at the bridge is presented in figure 8. Scour depths were \ncalculated assuming an infinite depth of erosive material and a homogeneous particle-size \ndistribution.\nUsually, computed scour depths are evaluated in combination with other information \nincluding (but not limited to) historical performance during flood events, the geomorphic \nstability assessment, existing scour protection measures, and the results of the hydraulic \nanalyses. Therefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr97397","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Olson, S.A., 1997, Level II scour analysis for Bridge 6 (ALBUTH00150006) on Town Highway 15, crossing Mud Creek, Alburg, Vermont: U.S. Geological Survey Open-File Report 97-397, iv, 50 p., https://doi.org/10.3133/ofr97397.","productDescription":"iv, 50 p.","numberOfPages":"55","costCenters":[],"links":[{"id":169878,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97397.PNG"},{"id":279738,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0397/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Alburg","otherGeospatial":"Mud Creek","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -73.375,44.875 ], [ -73.375,45.0 ], [ -73.25,45.0 ], [ -73.25,44.875 ], [ -73.375,44.875 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b16e4b07f02db6a55c6","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":240516,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":49941,"text":"ofr97393 - 1997 - Level II scour analysis for Bridge 36 (ANDOVT00110036) on VT 11, crossing Middle Branch Williams River, Andover, Vermont","interactions":[],"lastModifiedDate":"2013-12-19T14:10:14","indexId":"ofr97393","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-393","title":"Level II scour analysis for Bridge 36 (ANDOVT00110036) on VT 11, crossing Middle Branch Williams River, Andover, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nANDOVT00110036 on State Route 11 crossing the Middle Branch Williams River, \nAndover, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, \nincluding a quantitative analysis of stream stability and scour (U.S. Department of \nTransportation, 1993). Results of a Level I scour investigation also are included in \nAppendix E of this report. A Level I investigation provides a qualitative geomorphic \ncharacterization of the study site. Information on the bridge, gleaned from Vermont Agency \nof Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II \nanalyses and is found in Appendix D.\nThe site is in the Green Mountain section of the New England physiographic province in \nsouth-central Vermont. The 5.10-mi2\n drainage area is in a predominantly rural and forested \nbasin. In the vicinity of the study site, the surface cover is pasture on the upstream left bank \nand forested elsewhere throughout the reach.\nIn the study area, the Middle Branch Williams River has an incised, sinuous channel with a \nslope of approximately 0.02 ft/ft, an average channel top width of 38 ft and an average bank \nheight of 2 ft. The channel bed material ranges from sand to boulders with a median grain \nsize (D50) of 60.1 mm (0.197 ft). The geomorphic assessment at the time of the Level I and \nLevel II site visit on August 28, 1996, indicated that the reach was laterally unstable due to \na cut-bank on the left bank upstream, side bar formation on the left bank upstream, and a \ncombination of side bar formation and erosion occurring on the downstream right bank.\nThe State Route 11 crossing of the Middle Branch Williams River is a 28-ft-long, two-lane \nbridge consisting of one 25-foot concrete-beam span (Vermont Agency of Transportation, \nwritten communication, March 28, 1995). The opening length of the structure parallel to the \nbridge face is 25.3 ft.The bridge is supported by vertical, concrete abutments with \nwingwalls. The channel is skewed approximately 30 degrees to the opening and the \nopening-skew-to-roadway is also 30 degrees. \nA scour hole 0.5 ft deeper than the mean thalweg depth was observed 5 feet upstream of the \nbridge during the Level I assessment. Scour protection measures at the site include: type-2 \nstone fill (less than 36 inches diameter) along the left bank upstream, and type-4 stone fill \n(less than 60 inches diameter) along the entire base length of the upstream left wingwall, \nand at the upstream end of the upstream right wing wall. Additional details describing \nconditions at the site are included in the Level II Summary and Appendices D and E.\nScour depths and recommended rock rip-rap sizes were computed using the general \nguidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995). \nTotal scour at a highway crossing is comprised of three components: 1) long-term \nstreambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction \nin flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and \nabutments). Total scour is the sum of the three components. Equations are available to \ncompute depths for contraction and local scour and a summary of the results of these \ncomputations follows.\nContraction scour for all modelled flows ranged from 0.0 to 2.8 ft. The worst-case \ncontraction scour occurred at the 500-year discharge. Abutment scour ranged from 9.5 to \n13.7 ft. The worst-case abutment scour also occurred at the 500-year discharge. Additional \ninformation on scour depths and depths to armoring are included in the section titled “Scour \nResults”. Scoured-streambed elevations, based on the calculated scour depths, are presented \nin tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure \n8. Scour depths were calculated assuming an infinite depth of erosive material and a \nhomogeneous particle-size distribution. \nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr97393","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Striker, L.K., and Burns, R.L., 1997, Level II scour analysis for Bridge 36 (ANDOVT00110036) on VT 11, crossing Middle Branch Williams River, Andover, Vermont: U.S. Geological Survey Open-File Report 97-393, iv, 51 p., https://doi.org/10.3133/ofr97393.","productDescription":"iv, 51 p.","numberOfPages":"56","costCenters":[],"links":[{"id":169793,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97393.PNG"},{"id":279742,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0393/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Andover","otherGeospatial":"Williams River","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.75,43.125 ], [ -72.75,43.25 ], [ -72.5,43.25 ], [ -72.5,43.125 ], [ -72.75,43.125 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b19e4b07f02db6a7f81","contributors":{"authors":[{"text":"Striker, Lora K.","contributorId":41481,"corporation":false,"usgs":true,"family":"Striker","given":"Lora","email":"","middleInitial":"K.","affiliations":[],"preferred":false,"id":240508,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Burns, Rhonda L.","contributorId":51358,"corporation":false,"usgs":true,"family":"Burns","given":"Rhonda","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":240509,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49940,"text":"ofr97391 - 1997 - Level II scour analysis for Bridge 49 (FFIETH00290049) on Town Highway29, crossing Black Creek, Fairfield, Vermont","interactions":[],"lastModifiedDate":"2013-12-19T14:20:24","indexId":"ofr97391","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-391","title":"Level II scour analysis for Bridge 49 (FFIETH00290049) on Town Highway29, crossing Black Creek, Fairfield, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nFFIETH00290049 on Town Highway 29 crossing Black Creek, Fairfield, Vermont (figures \n1–8). A Level II study is a basic engineering analysis of the site, including a quantitative \nanalysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of \na Level I scour investigation also are included in Appendix E of this report. A Level I \ninvestigation provides a qualitative geomorphic characterization of the study site. \nInformation on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) \nfiles, was compiled prior to conducting Level I and Level II analyses and is found in \nAppendix D.\nThe site is in the Green Mountain section of the New England physiographic province in \nnorthwestern Vermont. The 83.5-mi2\n drainage area is in a predominantly rural and forested \nbasin. There is agricultural land in the basin as well, especially along the immediate river \nvalley. In the vicinity of the study site, the surface cover is pasture except for on the \ndownstream right bank which has row crops.\nIn the study area, Black Creek has an incised, meandering channel with a slope of \napproximately 0.0005 ft/ft, an average channel top width of 85 ft and an average bank \nheight of 9 ft. The channel bed material ranges from sand to cobble with a median grain size \n(D50) of 3.23 mm (0.0106 ft). The geomorphic assessment at the time of the Level I and \nLevel II site visit on July 13, 1995, indicated that the reach was laterally unstable. This \nassessment was due to apparent long term lateral movement of the channel in the vicinity of \nthe bridge.\nThe Town Highway 29 crossing of Black Creek is a 48-ft-long, one-lane bridge consisting \nof one 45-foot steel pony thru-truss type span (Vermont Agency of Transportation, written \ncommunication, March 8, 1995). The opening length of the structure parallel to the bridge \nface is 42.5 ft.The bridge is supported by vertical, concrete abutments. The channel is \nskewed approximately 30 degrees to the opening while the opening-skew-to-roadway is \nzero degrees. \nChannel scour, approximately 6 ft deeper than the mean thalweg depth, was observed \nthrough the immediate channel reach including underneath the bridge. Type-2 stone fill \n(less than 36 inches diameter) has been placed as a scour countermeasure along both \nabutments, on the channel bed under the bridge and along immediate channel banks \nupstream and downstream of the bridge. Additional details describing conditions at the site \nare included in the Level II Summary and Appendices D and E.\nScour depths and recommended rock rip-rap sizes were computed using the general \nguidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995). \nTotal scour at a highway crossing is comprised of three components: 1) long-term \nstreambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction \nin flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and \nabutments). Total scour is the sum of the three components. Equations are available to \ncompute depths for contraction and local scour and a summary of the results of these \ncomputations follows.\nContraction scour for all modelled flows ranged from 0.0 to 4.4 ft. The worst-case \ncontraction scour occurred at the 500-year discharge. Abutment scour ranged from 7.5 to \n14.3 ft and 12.2 to 16.3 ft on the left and right abutments respectively. The worst-case \nabutment scour occurred at the 500-year discharge. Additional information on scour depths \nand depths to armoring are included in the section titled “Scour Results”. Scouredstreambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. \nA cross-section of the scour computed at the bridge is presented in figure 8. Scour depths \nwere calculated assuming an infinite depth of erosive material and a homogeneous particlesize distribution. \nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr97391","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Olson, S.A., 1997, Level II scour analysis for Bridge 49 (FFIETH00290049) on Town Highway29, crossing Black Creek, Fairfield, Vermont: U.S. Geological Survey Open-File Report 97-391, iv, 52 p., https://doi.org/10.3133/ofr97391.","productDescription":"iv, 52 p.","numberOfPages":"57","costCenters":[],"links":[{"id":169792,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97391.PNG"},{"id":279743,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0391/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Fairfield","otherGeospatial":"Black Creek","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -73.0,44.75 ], [ -73.0,44.875 ], [ -72.875,44.875 ], [ -72.875,44.75 ], [ -73.0,44.75 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a5fb9","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":240507,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":49935,"text":"ofr97386 - 1997 - Level II scour analysis for Bridge 43 (CHELTH00460043) on Town Highway 46, crossing Jail Brook, Chelsea, Vermont","interactions":[],"lastModifiedDate":"2013-12-20T10:15:18","indexId":"ofr97386","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-386","title":"Level II scour analysis for Bridge 43 (CHELTH00460043) on Town Highway 46, crossing Jail Brook, Chelsea, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nCHELTH00460043 on Town Highway 46 crossing Jail Brook, Chelsea, Vermont (figures \n1–8). A Level II study is a basic engineering analysis of the site, including a quantitative \nanalysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of \na Level I scour investigation also are included in Appendix E of this report. A Level I \ninvestigation provides a qualitative geomorphic characterization of the study site. \nInformation on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) \nfiles, was compiled prior to conducting Level I and Level II analyses and is found in \nAppendix D.
\nThe site is in the New England Upland section of the New England physiographic province \nin central Vermont. The 4.68-mi2\n drainage area is in a predominantly rural and forested \nbasin. In the vicinity of the study site, the surface cover is best described as suburban with \nhomes, lawns, and a few trees.
\nIn the study area, Jail Brook has an incised, straight channel with a slope of approximately \n0.02 ft/ft, an average channel top width of 32 ft and an average bank height of 6 ft. The \nchannel bed material ranges from coarse sand to boulder with a median grain size (D50) of \n43.0 mm (0.141 ft). The geomorphic assessment at the time of the Level I and Level II site \nvisit on November 18, 1994, indicated that the reach was stable.
\nThe Town Highway 46 crossing of Jail Brook is a 27-ft-long, two-lane bridge consisting of \none 23-foot concrete span (Vermont Agency of Transportation, written communication, \nAugust 25, 1994). The opening length of the structure parallel to the bridge face is 22.8 \nft.The bridge is supported by vertical, concrete abutments with wingwalls. The channel is \nskewed approximately zero degrees to the opening and the opening-skew-to-roadway is \nalso zero degrees.
\nChannel scour was not observed. However, the left abutment footing was exposed one foot. \nScour countermeasures at the site consisted of type-2 stone fill (less than 36 inches \ndiameter) on the banks and road embankments upstream and downstream of the bridge. \nAdditional details describing conditions at the site are included in the Level II Summary \nand Appendices D and E.
\nScour depths and recommended rock rip-rap sizes were computed using the general \nguidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995). \nTotal scour at a highway crossing is comprised of three components: 1) long-term \nstreambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction \nin flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and \nabutments). Total scour is the sum of the three components. Equations are available to \ncompute depths for contraction and local scour and a summary of the results of these \ncomputations follows.
\nContraction scour for all modelled flows ranged from 1.1 to 1.2 ft. The worst-case \ncontraction scour occurred at the 500-year discharge. Abutment scour ranged from 5.0 to \n6.5 ft at the left abutment and 4.7 to 6.2 ft at the right abutment. The worst-case abutment \nscour occurred at the 500-year discharge. Additional information on scour depths and \ndepths to armoring are included in the section titled “Scour Results”. Scoured-streambed \nelevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were \ncalculated assuming an infinite depth of erosive material and a homogeneous particle-size \ndistribution.
\nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr97386","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Olson, S.A., 1997, Level II scour analysis for Bridge 43 (CHELTH00460043) on Town Highway 46, crossing Jail Brook, Chelsea, Vermont: U.S. Geological Survey Open-File Report 97-386, iv, 48 p., https://doi.org/10.3133/ofr97386.","productDescription":"iv, 48 p.","numberOfPages":"53","costCenters":[],"links":[{"id":169725,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97386.PNG"},{"id":279748,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0386/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Chelsea","otherGeospatial":"Jail Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.5,43.875 ], [ -72.5,44.0 ], [ -72.375,44.0 ], [ -72.375,43.875 ], [ -72.5,43.875 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a5f8e","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":240500,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":49939,"text":"ofr97390 - 1997 - Level II scour analysis for Bridge 24 (MANCUS00070024) on U.S. Route 7, crossing Lye Brook, Manchester, Vermont","interactions":[],"lastModifiedDate":"2013-12-20T09:38:07","indexId":"ofr97390","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-390","title":"Level II scour analysis for Bridge 24 (MANCUS00070024) on U.S. Route 7, crossing Lye Brook, Manchester, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nMANCUS00070024 on U.S. Route 7 crossing Lye Brook, Manchester, Vermont (figures \n1–8). A Level II study is a basic engineering analysis of the site, including a quantitative \nanalysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of \na Level I scour investigation also are included in Appendix E of this report. A Level I \ninvestigation provides a qualitative geomorphic characterization of the study site. \nInformation on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) \nfiles, was compiled prior to conducting Level I and Level II analyses and is found in \nAppendix D.
\nThe site is in the Taconic section of the New England physiographic province in \nsouthwestern Vermont. The 8.13-mi2\n drainage area is in a predominantly rural and forested \nbasin. In the vicinity of the study site, the primary surface cover consists of brush and trees.
\nIn the study area, Lye Brook has an incised, sinuous channel with a slope of approximately \n0.03 ft/ft, an average channel top width of 66 ft and an average bank height of 11 ft. The \nchannel bed material ranges from gravel to boulder with a median grain size (D50) of 90.0 \nmm (0.295 ft). The geomorphic assessment at the time of the Level I and Level II site visit \non August 6, 1996, indicated that the reach was stable. Although, the immediate reach is \nconsidered stable, upstream of the bridge the Lye Brook valley is very steep (0.05 ft/ft). \nExtreme events in a valley this steep may quickly reveal the instability of the channel. In the \nFlood Insurance Study for the Town of Manchester (Federal Emergency Management \nAgency, January, 1985), Lye Brook’s overbanks were described as “boulder strewn” after \nthe August 1976 flood.
\nThe U.S. Route 7 crossing of Lye Brook is a 28-ft-long, two-lane bridge consisting of one \n25-foot concrete span (Vermont Agency of Transportation, written communication, \nSeptember 28, 1995). The bridge is supported by vertical, concrete abutments with \nwingwalls. The channel is skewed approximately 45 degrees to the opening while the \nopening-skew-to-roadway is 55 degrees.
\nAt the time of construction, the downstream channel was relocated (written communication, \nDan Landry, VTAOT, January 2, 1997). A levee on the downstream right bank was also \nconstructed and is protected by type-4 stone-fill (less than 60 inches diameter) extending \nfrom the bridge to more than 300 feet downstream. Type-2 stone fill (less than 36 inches \ndiameter) covers the downstream right bank from the bridge to more than 300 feet \ndownstream. Type-2 stone-fill also extends from the bridge to 220 feet upstream on both \nupstream banks. Additional details describing conditions at the site are included in the \nLevel II Summary and Appendices D and E.
\nScour depths and recommended rock rip-rap sizes were computed using the general \nguidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995) \nfor the 100- and 500-year discharges. In addition, the incipient roadway-overtopping \ndischarge is analyzed since it has the potential of being the worst-case scour scenario. Total \nscour at a highway crossing is comprised of three components: 1) long-term streambed \ndegradation; 2) contraction scour (due to accelerated flow caused by a reduction in flow \narea at a bridge) and; 3) local scour (caused by accelerated flow around piers and \nabutments). Total scour is the sum of the three components. Equations are available to \ncompute depths for contraction and local scour and a summary of the results of these \ncomputations follows.
\nContraction scour for all modelled flows ranged from 1.0 to 1.6 ft. The worst-case \ncontraction scour occurred at the 500-year discharge. Abutment scour computations for the \nleft abutment ranged from 14.5 to 16.1 ft. with the worst-case occurring at the 100-year \ndischarge. Abutment scour computations for the right abutment ranged from 6.9 to 10.4 ft. \nwith the worst-case occurring at the 500-year discharge. Additional information on scour \ndepths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. \nA cross-section of the scour computed at the bridge is presented in figure 8. Scour depths \nwere calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution.
\nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr97390","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Olson, S.A., 1997, Level II scour analysis for Bridge 24 (MANCUS00070024) on U.S. Route 7, crossing Lye Brook, Manchester, Vermont: U.S. Geological Survey Open-File Report 97-390, iv, 52 p., https://doi.org/10.3133/ofr97390.","productDescription":"iv, 52 p.","numberOfPages":"57","costCenters":[],"links":[{"id":169791,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/usgs_thumb.jpg"},{"id":279744,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0390/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Manchester","otherGeospatial":"Lye Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -73.125,43.125 ], [ -73.125,43.25 ], [ -73.0,43.25 ], [ -73.0,43.125 ], [ -73.125,43.125 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b19e4b07f02db6a7f71","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":240506,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":49936,"text":"ofr97387 - 1997 - Level II scour analysis for Bridge 10 (WNDHTH00020010) on Town Highway 2, crossing the Middle Branch of the Williams River, Windham, Vermont","interactions":[],"lastModifiedDate":"2013-12-20T10:04:56","indexId":"ofr97387","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-387","title":"Level II scour analysis for Bridge 10 (WNDHTH00020010) on Town Highway 2, crossing the Middle Branch of the Williams River, Windham, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nWNDHTH00020010 on Town Highway 2 crossing the Middle Branch Williams River, \nWindham, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the \nsite, including a quantitative analysis of stream stability and scour (U.S. Department of \nTransportation, 1993). Results of a Level I scour investigation also are included in \nAppendix E of this report. A Level I investigation provides a qualitative geomorphic \ncharacterization of the study site. Information on the bridge, gleaned from Vermont Agency \nof Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II \nanalyses and is found in Appendix D.
\nThe site is in the Green Mountain section of the New England physiographic province in \nsouth central Vermont. The 1.44-mi2\n drainage area is in a predominantly rural and forested \nbasin. In the vicinity of the study site, the predominate surface cover upstream of the bridge \nis pasture on the left bank and forest on the right bank. Downstream of the bridge the \nsurface cover consists of forest on the right bank and grass on the left bank.
\nIn the study area, the Middle Branch Williams River has an incised, sinuous channel with a \nslope of approximately 0.03 ft/ft, an average channel top width of 28 ft and an average bank \nheight of 5 ft. The channel bed material ranges from gravel to boulder with a median grain \nsize (D50) of 61.4 mm (0.201 ft). The geomorphic assessment at the time of the Level I and \nLevel II site visit on August 22, 1996, indicated that the reach was stable.
\nThe Town Highway 2 crossing of the Middle Branch Williams River is a \n25-ft-long, two-lane bridge consisting of one 22-foot concrete slab span (Vermont Agency \nof Transportation, written communication, March 31, 1995). The bridge is supported by \nvertical, concrete abutments with wingwalls. The channel is skewed approximately 60 \ndegrees to the opening while the opening-skew-to-roadway is 50 degrees.
\nThe scour protection measures at the site included type-2 stone fill (less than 36 inches \ndiameter) along both upstream banks. The scour protection measures downstream were type \n-1 stone fill (less than 12 inches diameter) on the left bank and type-3 stone fill (less than 48 \ninches diameter) on the right bank. Scour protection measures do not exist underneath the \nbridge. Additional details describing conditions at the site are included in the Level II \nSummary and Appendices D and E.
\nScour depths and rock rip-rap sizes were computed using the general guidelines described \nin Hydraulic Engineering Circular 18 (Richardson and others, 1995). Total scour at a \nhighway crossing is comprised of three components: 1) long-term streambed degradation; \n2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) \nand; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is \nthe sum of the three components. Equations are available to compute depths for contraction \nand local scour and a summary of the results of these computations follows.
\nContraction scour for modelled flows ranged from 0.9 to 2.2 ft. The worst-case contraction \nscour occurred at the 500-year discharge. Abutment scour ranged from 8.5 to 8.8 ft along \nthe right abutment and from 8.7 to 10.1 ft along the left abutment. The worst-case abutment \nscour at the right abutment occurred at the 100-year discharge and at the left abutment at the \n500-year discharge. Additional information on scour depths and depths to armoring are \nincluded in the section titled “Scour Results”. Scoured-streambed elevations, based on the \ncalculated scour depths, are presented in tables 1 and 2. A cross-section of the scour \ncomputed at the bridge is presented in figure 8. Scour depths were calculated assuming an \ninfinite depth of erosive material and a homogeneous particle-size distribution.
\nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr97387","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Striker, L.K., and Wild, E.C., 1997, Level II scour analysis for Bridge 10 (WNDHTH00020010) on Town Highway 2, crossing the Middle Branch of the Williams River, Windham, Vermont: U.S. Geological Survey Open-File Report 97-387, iv, 49 p., https://doi.org/10.3133/ofr97387.","productDescription":"iv, 49 p.","numberOfPages":"54","costCenters":[],"links":[{"id":169788,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97387.PNG"},{"id":279747,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0387/report.pdf"}],"scale":"25000","country":"United States","state":"Vermont","city":"Windham","otherGeospatial":"Middle Branch Williams River","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.75,43.125 ], [ -72.75,43.25 ], [ -72.5,43.25 ], [ -72.5,43.125 ], [ -72.75,43.125 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b1ae4b07f02db6a8420","contributors":{"authors":[{"text":"Striker, Lora K.","contributorId":41481,"corporation":false,"usgs":true,"family":"Striker","given":"Lora","email":"","middleInitial":"K.","affiliations":[],"preferred":false,"id":240502,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Wild, Emily C. 0000-0001-6157-7629 ecwild@usgs.gov","orcid":"https://orcid.org/0000-0001-6157-7629","contributorId":1810,"corporation":false,"usgs":true,"family":"Wild","given":"Emily","email":"ecwild@usgs.gov","middleInitial":"C.","affiliations":[{"id":5081,"text":"Libraries","active":false,"usgs":true}],"preferred":false,"id":240501,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49938,"text":"ofr97389 - 1997 - Level II scour analysis for Bridge 9 (BLOOVT01020009) on State Route 102, crossing the Nulhegan River, Bloomfield, Vermont","interactions":[],"lastModifiedDate":"2013-12-20T09:46:37","indexId":"ofr97389","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-389","title":"Level II scour analysis for Bridge 9 (BLOOVT01020009) on State Route 102, crossing the Nulhegan River, Bloomfield, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nBLOOVT01020009 on State Route 102 crossing the Nulhegan River, Bloomfield, Vermont \n(figures 1–8). A Level II study is a basic engineering analysis of the site, including a \nquantitative analysis of stream stability and scour (U.S. Department of Transportation, \n1993). Results of a Level I scour investigation also are included in Appendix E of this \nreport. A Level I investigation provides a qualitative geomorphic characterization of the \nstudy site. Information on the bridge, gleaned from Vermont Agency of Transportation \n(VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is \nfound in Appendix D.
\nThe site is in the White Mountain section of the New England physiographic province in \nnortheastern Vermont. The 144-mi2\n drainage area is in a predominantly rural and forested \nbasin. In the vicinity of the study site, the surface cover is forest except for the downstream \nright bank area which is shrub and brush land. The Nulhegan River flows into the \nConnecticut River 210 feet downstream of this bridge.
\nIn the study area, the Nulhegan River has an incised, sinuous channel with a slope of \napproximately 0.005 ft/ft, an average channel top width of 164 ft and an average channel \ndepth of 5 ft. The predominant channel bed material is cobble with a median grain size \n(D50) of 152 mm (0.498 ft). The geomorphic assessment at the time of the Level I and Level \nII site visit on July 6, 1995, indicated that the reach was laterally unstable. This was due to \nnumerous point bars and side bars indicating an unstable thalweg.
\nThe State Route 102 crossing of the Nulhegan River is a 134-ft-long, two-lane bridge \nconsisting of one 130-foot steel-truss span (Vermont Agency of Transportation, written \ncommunication, August 4, 1994). The field measured clear span was 131.6 ft. The bridge is \nsupported by vertical, concrete abutments with rip-rapped spill-through slopes. The channel \nis skewed approximately 25 degrees to the opening while the measured opening-skew-to-roadway is 5 degrees.
\nA scour hole 3.5 ft deeper than the mean thalweg depth was observed 250 ft upstream \nduring the Level I assessment. It was noted that the scour was localized on the right bank \nside and due to the presence of an old abutment. Scour countermeasures include the type-3 \nstone-fill (less than 48 inches diameter) which forms the spill-through slopes of the \nabutments. Additional details describing conditions at the site are included in the Level II \nSummary 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.
\nComputed contraction scour for all modelled flows was zero ft. Abutment scour ranged \nfrom 4.5 to 5.0 ft at the left abutment and 9.6 to 11.4 ft at the right abutment. The worst-case \nabutment scour occurred at the 500-year discharge. Additional information on scour depths \nand depths to armoring are included in the section titled “Scour Results”. Scoured \nstreambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. \nA cross-section of the scour computed at the bridge is presented in figure 8. Scour depths \nwere calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution.
\nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr97389","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Ayotte, J., 1997, Level II scour analysis for Bridge 9 (BLOOVT01020009) on State Route 102, crossing the Nulhegan River, Bloomfield, Vermont: U.S. Geological Survey Open-File Report 97-389, iv, 48 p., https://doi.org/10.3133/ofr97389.","productDescription":"iv, 48 p.","numberOfPages":"53","costCenters":[],"links":[{"id":169790,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97389.PNG"},{"id":279745,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0389/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":"4f4e4b16e4b07f02db6a55b3","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":240505,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":49963,"text":"ofr97592 - 1997 - Level II scour analysis for Bridge 48 (FFIETH00300048) on Town Highway 30, crossing Wanzer Brook, Fairfield, Vermont","interactions":[],"lastModifiedDate":"2013-12-18T14:02:55","indexId":"ofr97592","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-592","title":"Level II scour analysis for Bridge 48 (FFIETH00300048) on Town Highway 30, crossing Wanzer Brook, Fairfield, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nFFIETH00300048 on Town Highway 30 crossing Wanzer Brook, Fairfield, Vermont \n(figures 1–8). A Level II study is a basic engineering analysis of the site, including a \nquantitative analysis of stream stability and scour (U.S. Department of Transportation, \n1993). Results of a Level I scour investigation also are included in Appendix E of this \nreport. A Level I investigation provides a qualitative geomorphic characterization of the \nstudy site. Information on the bridge, gleaned from Vermont Agency of Transportation \n(VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is \nfound in Appendix D.
\nThe site is in the Green Mountain section of the New England physiographic province in \nnorthwestern Vermont. The 6.78-mi2\n drainage area is in a predominantly rural and forested \nbasin. In the vicinity of the study site, the surface cover upstream of the bridge and on the \ndownstream right bank is primarily pasture. The downstream left bank is forested.
\nIn the study area, Wanzer Brook has an incised, straight channel with a slope of \napproximately 0.03 ft/ft, an average channel top width of 65 ft and an average bank height \nof 5 ft. The channel bed material is cobble with a median grain size (D50) of 111 mm (0.364 \nft). The geomorphic assessment at the time of the Level I and Level II site visit on July 11, \n1995, indicated that the reach was stable.
\nThe Town Highway 30 crossing of Wanzer Brook is a 31-ft-long, two-lane bridge \nconsisting of one 28-foot steel-beam span (Vermont Agency of Transportation, written \ncommunication, March 8, 1995). The opening length of the structure parallel to the bridge \nface is 26 ft.The bridge is supported by vertical stone wall abutments with concrete caps and \n“kneewall” footings. The channel is skewed approximately 25 degrees to the opening while \nthe measured opening-skew-to-roadway is 20 degrees.
\nA scour hole 1.5 ft deeper than the mean thalweg depth was observed along the downstream \nleft retaining wall (extended concrete footing) during the Level I assessment. It was also \nobserved that the right abutment is undermined with a scour depth of 0.5 ft. The scour \nprotection at the site was limited to four large boulders (type-4, less than 60 inches \ndiameter) along the downstream right retaining wall. The channel under the bridge is a \n“corduroy” log mat floor composed of 13 logs which are parallel to the bridge face and \nextend from 5 ft under the bridge to the downstream bridge face. The most downstream log \nis approximately 0.3 to 0.4 ft higher than the other logs and controls flow at lower flows. \nAdditional details describing conditions at the site are included in the Level II Summary \nand Appendices D and E.
\nScour depths and recommended rock rip-rap sizes were computed using the general \nguidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995). \nTotal scour at a highway crossing is comprised of three components: 1) long-term \nstreambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction \nin flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and \nabutments). Total scour is the sum of the three components. Equations are available to \ncompute depths for contraction and local scour and a summary of the results of these \ncomputations follows.
\nContraction scour for all modelled flows ranged from 0.3 to 0.6 ft. The worst-case \ncontraction scour occurred at the 500-year discharge. Abutment scour ranged from 14.1 to \n16.0 ft at the left abutment and from 6.8 to 7.6 ft at the right abutment. The worst-case \nabutment scour occurred at the 500-year discharge. Additional information on scour depths \nand depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. \nA cross-section of the scour computed at the bridge is presented in figure 8. Scour depths \nwere calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution.
\nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr97592","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Flynn, R.H., and Boehmler, E.M., 1997, Level II scour analysis for Bridge 48 (FFIETH00300048) on Town Highway 30, crossing Wanzer Brook, Fairfield, Vermont: U.S. Geological Survey Open-File Report 97-592, iv, 48 p., https://doi.org/10.3133/ofr97592.","productDescription":"iv, 48 p.","numberOfPages":"53","costCenters":[],"links":[{"id":175622,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97592.GIF"},{"id":279715,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0592/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Fairfield","otherGeospatial":"Wanzer Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -73.0,44.75 ], [ -73.0,44.875 ], [ -72.875,44.875 ], [ -72.875,44.75 ], [ -73.0,44.75 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a606a","contributors":{"authors":[{"text":"Flynn, Robert H. rflynn@usgs.gov","contributorId":2137,"corporation":false,"usgs":true,"family":"Flynn","given":"Robert","email":"rflynn@usgs.gov","middleInitial":"H.","affiliations":[{"id":405,"text":"NH/VT office of New England Water Science Center","active":true,"usgs":true}],"preferred":true,"id":240548,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Boehmler, Erick M.","contributorId":96303,"corporation":false,"usgs":true,"family":"Boehmler","given":"Erick","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":240549,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49960,"text":"ofr97581 - 1997 - Level II scour analysis for Bridge 16 (CHESVT01030016) on State Route 103, crossing the Williams River, Chester, Vermont","interactions":[],"lastModifiedDate":"2013-12-18T14:38:25","indexId":"ofr97581","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-581","title":"Level II scour analysis for Bridge 16 (CHESVT01030016) on State Route 103, crossing the Williams River, Chester, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nCHESVT01030016 on State Route 103 crossing the Williams River, Chester, Vermont \n(figures 1–8). A Level II study is a basic engineering analysis of the site, including a \nquantitative analysis of stream stability and scour (U.S. Department of Transportation, \n1993). Results of a Level I scour investigation also are included in Appendix E of this \nreport. A Level I investigation provides a qualitative geomorphic characterization of the \nstudy site. Information on the bridge, gleaned from Vermont Agency of Transportation \n(VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is \nfound in Appendix D.
\nThe site is in the New England Upland section of the New England physiographic province \nin southeastern Vermont. The 15.1-mi2\n drainage area is in a predominantly rural and \nforested basin. In the vicinity of the study site, the surface cover is pasture except for the \ndownstream right overbank which is forested.
\nIn the study area, the Williams River has an incised, straight channel with a slope of \napproximately 0.008 ft/ft, an average channel top width of 56 ft and an average bank height \nof 6 ft. The channel bed material ranges from gravel to cobbles with a median grain size \n(D50) of 67.5 mm (0.222 ft). The geomorphic assessment at the time of the Level I and \nLevel II site visit on September 16, 1996, indicated that the reach was stable.
\nThe State Route 103 crossing of the Williams River is a 162-ft-long, two-lane bridge \nconsisting of three steel-beam spans (Vermont Agency of Transportation, written \ncommunication, March 13, 1995). The opening length of the structure parallel to the bridge \nface is 157.7 ft.The bridge is supported by vertical, concrete abutments and piers with no \nwingwalls. The channel is skewed approximately 55 degrees to the opening while the \nopening-skew-to-roadway is also 55 degrees.
\nThe scour protection measures at the site included type-4 stone fill (less than 60 inches \ndiameter) along the upstream left bank. There was type-3 stone fill (less than 48 inches \ndiameter) along the upstream right bank and both spill-through embankments and both \ndownstream banks. There was type-1 stone fill (less than 12 inches diameter) along the \nupstream right and downstream left road embankments. Additional details describing \nconditions at the site are included in the Level II Summary and Appendices D and E.
\nScour depths and recommended rock rip-rap sizes were computed using the general \nguidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995). \nTotal scour at a highway crossing is comprised of three components: 1) long-term \nstreambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction \nin flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and \nabutments). Total scour is the sum of the three components. Equations are available to \ncompute depths for contraction and local scour and a summary of the results of these \ncomputations follows.
\nContraction scour for all modelled flows was 0.0. Abutment scour ranged from 6.4 to 9.0 ft. \nThe worst-case abutment scour occurred at the 500-year discharge. Pier scour ranged from \n7.9 to 10.1 ft. The worst-case pier scour occurred at the incipient-overtopping discharge for \nboth piers. Additional information on scour depths and depths to armoring are included in \nthe section titled “Scour Results”. Scoured-streambed elevations, based on the calculated \nscour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the \nbridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of \nerosive material and a homogeneous particle-size distribution.
\nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr97581","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Ivanoff, M.A., and Hammond, R.E., 1997, Level II scour analysis for Bridge 16 (CHESVT01030016) on State Route 103, crossing the Williams River, Chester, Vermont: U.S. Geological Survey Open-File Report 97-581, iv, 54 p., https://doi.org/10.3133/ofr97581.","productDescription":"iv, 54 p.","numberOfPages":"59","costCenters":[],"links":[{"id":175619,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97581.GIF"},{"id":279718,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0581/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Chester","otherGeospatial":"Williams River","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.75,43.25 ], [ -72.75,43.375 ], [ -72.5,43.375 ], [ -72.5,43.25 ], [ -72.75,43.25 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b1ae4b07f02db6a827c","contributors":{"authors":[{"text":"Ivanoff, Michael A.","contributorId":27105,"corporation":false,"usgs":true,"family":"Ivanoff","given":"Michael","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":240543,"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":240544,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":50008,"text":"ofr97772 - 1997 - Level II scour analysis for Bridge 18 (SHEFTH00410018) on Town Highway 41, crossing Millers Run, Sheffield, Vermont","interactions":[],"lastModifiedDate":"2016-08-25T14:15:28","indexId":"ofr97772","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-772","title":"Level II scour analysis for Bridge 18 (SHEFTH00410018) on Town Highway 41, crossing Millers Run, Sheffield, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure SHEFTH00410018 on Town Highway 41 crossing Millers Run, Sheffield, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including a quantitative analysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of a Level I scour investigation also are included in Appendix E of this report. A Level I investigation provides a qualitative geomorphic characterization of the study site. Information on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is found in Appendix D.
The site is in the White Mountain section of the New England physiographic province in northeastern Vermont. The 16.2-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is grass upstream and downstream of the bridge while the immediate banks have dense woody vegetation.
In the study area, Millers Run has an incised, straight channel with a slope of approximately 0.01 ft/ft, an average channel top width of 50 ft and an average bank height of 6 ft. The channel bed material ranges from sand to boulder with a median grain size (D50) of 50.9 mm (0.167 ft). The geomorphic assessment at the time of the Level I and Level II site visit on August 1, 1995, indicated that the reach was laterally unstable, which is evident in the moderate to severe fluvial erosion in the upstream reach.
The Town Highway 41 crossing of the Millers Run is a 30-ft-long, one-lane bridge consisting of a 28-foot steel-stringer span (Vermont Agency of Transportation, written communication, March 28, 1995). The opening length of the structure parallel to the bridge face is 22.2 ft. The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 20 degrees to the opening. The computed opening-skewto-roadway is 5 degrees, while it is zero degrees in the historical form.
A scour hole 1.0 ft deeper than the mean thalweg depth was observed along the left abutment during the Level I assessment. The scour protection measure at the site includes type-1 stone fill (less than 12 inches diameter) along the upstream right wingwall and the upstream left wingwall. Type-2 stone fill (less than 36 inches diameter) extends along the downstream end of the downstream left wingwall, the upstream right bank and the downstream left bank. The downstream right bank is protected by type-2 stone fill and a stone masonry wall. Additional details describing conditions at the site are included in the Level II Summary and Appendices D and E.
Scour depths and recommended rock rip-rap sizes were computed using the general guidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995) for the 100- and 500-year discharges. In addition, the incipient roadway-overtopping discharge is determined and analyzed as another potential worst-case scour scenario. Total scour at a highway crossing is comprised of three components: 1) long-term streambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is the sum of the three components. Equations are available to compute depths for contraction and local scour and a summary of the results of these computations follows.
Contraction scour for all modelled flows ranged from 0.2 to 1.8 ft. The worst-case contraction scour occurred at the 100-year and 500-year discharges. Left abutment scour ranged from 14.1 to 16.4 ft. The worst-case left abutment scour occurred at the 500-year discharge. Right abutment scour ranged from 6.9 to 9.3 ft. The worst-case right abutment scour occurred at the incipient roadway-overtopping discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution.
It is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, computed scour depths are evaluated in combination with other information including (but not limited to) historical performance during flood events, the geomorphic stability assessment, existing scour protection measures, and the results of the hydraulic analyses. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr97772","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Wild, E.C., and Boehmler, E.M., 1997, Level II scour analysis for Bridge 18 (SHEFTH00410018) on Town Highway 41, crossing Millers Run, Sheffield, Vermont: U.S. Geological Survey Open-File Report 97-772, iv, 51 p., https://doi.org/10.3133/ofr97772.","productDescription":"iv, 51 p.","numberOfPages":"56","costCenters":[],"links":[{"id":176806,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97772.PNG"},{"id":279671,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0772/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Sheffield","otherGeospatial":"Millers Run","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":"4f4e4b1ae4b07f02db6a81cb","contributors":{"authors":[{"text":"Wild, Emily C. 0000-0001-6157-7629 ecwild@usgs.gov","orcid":"https://orcid.org/0000-0001-6157-7629","contributorId":1810,"corporation":false,"usgs":true,"family":"Wild","given":"Emily","email":"ecwild@usgs.gov","middleInitial":"C.","affiliations":[{"id":5081,"text":"Libraries","active":false,"usgs":true}],"preferred":false,"id":240625,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Boehmler, Erick M.","contributorId":96303,"corporation":false,"usgs":true,"family":"Boehmler","given":"Erick","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":240626,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49869,"text":"ofr972 - 1997 - Level II scour analysis for Bridge 17 (POMFTH00010017) on Town Highway 1 (FAS 166) crossing Mill Brook, Pomfret, Vermont","interactions":[],"lastModifiedDate":"2014-01-07T10:28:17","indexId":"ofr972","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-2","title":"Level II scour analysis for Bridge 17 (POMFTH00010017) on Town Highway 1 (FAS 166) crossing Mill Brook, Pomfret, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nPOMFTH00010017 on Town Highway 1 crossing Mill Brook, Pomfret, Vermont (figures \n1–8). A Level II study is a basic engineering analysis of the site, including a quantitative \nanalysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of \na Level I scour investigation also are included in Appendix E of this report. A Level I \ninvestigation provides a qualitative geomorphic characterization of the study site. \nInformation on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) \nfiles, was compiled prior to conducting Level I and Level II analyses and is found in \nAppendix D.\nThe site is in the Green Mountain section of the New England physiographic province in \ncentral Vermont. The 8.11-mi2\n drainage area is in a predominantly rural and forested basin. \nIn the vicinity of the study site, the surface cover is pasture.\nIn the study area, Mill Brook has a sinuous channel with a slope of approximately 0.009 ft/\nft, an average channel top width of 30 ft and an average channel depth of 3 ft. The \npredominant channel bed materials are gravel and cobbles with a median grain size (D50) of \n71.9 mm (0.236 ft). The geomorphic assessment at the time of the Level I and Level II site \nvisit on July 25, 1996, indicated that the reach was stable.\nThe Town Highway 1 crossing of Mill Brook is a 54-ft-long, two-lane bridge consisting of \none 52-foot steel-beam span (Vermont Agency of Transportation, written communication, \nAugust 23, 1994). The bridge is supported by vertical, concrete abutments with spillthrough embankments. The channel is skewed approximately 15 degrees to the opening and \nthe opening-skew-to-roadway is 15 degrees. \nThe scour protection measures at the site were type-3 stone riprap (less than 48 inches \ndiameter) on the spill-through embankments of each abutment and type-2 stone fill (less \nthan 24 inches diameter) on the banks downstream. Additional details describing conditions \nat the site are included in the Level II Summary and Appendices D and E.\nScour depths and rock rip-rap sizes were computed using the general guidelines described \nin Hydraulic Engineering Circular 18 (Richardson and others, 1995). Total scour at a \nhighway crossing is comprised of three components: 1) long-term streambed degradation; \n2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) \nand; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is \nthe sum of the three components. Equations are available to compute depths for contraction \nand local scour and a summary of the results of these computations follows.\nContraction scour for all modelled flows ranged from 0.0 to 0.9 ft. The worst-case \ncontraction scour occurred at the 500-year discharge. Abutment scour ranged from 3.6 to \n7.1 ft. The worst-case abutment scour also occurred at the 500-year discharge. Additional \ninformation on scour depths and depths to armoring are included in the section titled “Scour \nResults”. Scoured-streambed elevations, based on the calculated scour depths, are presented \nin tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure \n8. Scour depths were calculated assuming an infinite depth of erosive material and a \nhomogeneous particle-size distribution. \nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr972","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Boehmler, E.M., and Hammond, R.E., 1997, Level II scour analysis for Bridge 17 (POMFTH00010017) on Town Highway 1 (FAS 166) crossing Mill Brook, Pomfret, Vermont: U.S. Geological Survey Open-File Report 97-2, iv, 49 p., https://doi.org/10.3133/ofr972.","productDescription":"iv, 49 p.","numberOfPages":"54","costCenters":[],"links":[{"id":169561,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr972.PNG"},{"id":279831,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0002/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Pomfret","otherGeospatial":"Mill 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":"4f4e4b1ae4b07f02db6a8234","contributors":{"authors":[{"text":"Boehmler, Erick M.","contributorId":96303,"corporation":false,"usgs":true,"family":"Boehmler","given":"Erick","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":240392,"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":240391,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49870,"text":"ofr973 - 1997 - Level II scour analysis for Bridge 120 (LEICUS00070120) on U.S. Route 7, crossing the Leicester River, Leicester, Vermont","interactions":[],"lastModifiedDate":"2014-01-07T10:41:22","indexId":"ofr973","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-3","title":"Level II scour analysis for Bridge 120 (LEICUS00070120) on U.S. Route 7, crossing the Leicester River, Leicester, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nLEICUS00070120 on U. S. Route 7 crossing the Leicester River, Leicester, Vermont \n(figures 1–8). A Level II study is a basic engineering analysis of the site, including a \nquantitative analysis of stream stability and scour (U.S. Department of Transportation, \n1993). Results of a Level I scour investigation also are included in Appendix E of this \nreport. A Level I investigation provides a qualitative geomorphic characterization of the \nstudy site. Information on the bridge, gleaned from Vermont Agency of Transportation \n(VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is \nfound in Appendix D.\nThe site is in the Green Mountain section of the New England physiographic province in \nwest-central Vermont. The 23.0-mi2\n drainage area is in a predominantly rural and forested\nbasin. In the vicinity of the study site, the surface cover consists of shrubs, brush, and \npasture with some trees except for the upstream left overbank area which is forest.\nIn the study area, the Leicester River has a sinuous channel with a slope of approximately \n0.002 ft/ft, an average channel top width of 52 ft and an average channel depth of 3 ft. The \npredominant channel bed material is sand and gravel with a median grain size (D50) of 3.10 \nmm (0.0102 ft). The geomorphic assessment at the time of the Level I and Level II site visit \non September 18, 1995, indicated that the reach was laterally unstable. Lateral instability \nwas evident with the presence of some bank material failure and fallen or leaning vegetation \nat cut-banks upstream and downstream of this site. Point bars also were found near this site.\nThe U. S. Route 7 crossing of the Leicester Riveris a 108-ft-long, two-lane bridge \nconsisting of two 52-foot steel-beam spans (Vermont Agency of Transportation, written \ncommunication, March 13, 1995). The bridge is supported by vertical, concrete abutment \nwalls with stone fill spill-through embankments on each abutment and one pier. The \nchannel is skewed approximately 30 degrees to the opening while the opening-skew-toroadway is 15 degrees.\nThe only scour protection measure at the site was type-3 stone fill (less than 48 inches \ndiameter) on the spill-through embankments of each abutment. Additional details \ndescribing conditions at the site are included in the Level II Summary and Appendices D \nand E.\nScour depths and rock rip-rap sizes were computed using the general guidelines described \nin Hydraulic Engineering Circular 18 (Richardson and others, 1995). Total scour at a \nhighway crossing is comprised of three components: 1) long-term streambed degradation; \n2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) \nand; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is \nthe sum of the three components. Equations are available to compute depths for contraction \nand local scour and a summary of the results of these computations follows.\nContraction scour for all modelled flows ranged from 3.8 to 6.1 ft. The worst-case \ncontraction scour occurred at the 500-year discharge. Abutment scour ranged from 4.0 to \n6.7 ft. The worst-case abutment scour also occurred at the 500-year discharge. Pier scour \nranged from 9.1 to 10.2. The worst-case pier scour occurred at the 500-year discharge. \nAdditional information on scour depths and depths to armoring are included in the section \ntitled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, \nare presented in tables 1 and 2. A cross-section of the scour computed at the bridge is \npresented in figure 8. Scour depths were calculated assuming an infinite depth of erosive \nmaterial and a homogeneous particle-size distribution. \nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr973","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Boehmler, E.M., and Severance, T., 1997, Level II scour analysis for Bridge 120 (LEICUS00070120) on U.S. Route 7, crossing the Leicester River, Leicester, Vermont: U.S. Geological Survey Open-File Report 97-3, iv, 49 p., https://doi.org/10.3133/ofr973.","productDescription":"iv, 49 p.","numberOfPages":"54","costCenters":[],"links":[{"id":169562,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr973.PNG"},{"id":279830,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0003/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Leicester","otherGeospatial":"Leicester River","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -73.125,43.875 ], [ -73.125,44.0 ], [ -73.0,44.0 ], [ -73.0,43.875 ], [ -73.125,43.875 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b1ae4b07f02db6a83ba","contributors":{"authors":[{"text":"Boehmler, Erick M.","contributorId":96303,"corporation":false,"usgs":true,"family":"Boehmler","given":"Erick","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":240393,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Severance, Timothy","contributorId":104927,"corporation":false,"usgs":true,"family":"Severance","given":"Timothy","email":"","affiliations":[],"preferred":false,"id":240394,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49871,"text":"ofr977 - 1997 - Level II scour analysis for Bridge 144 (ROCHVT01000144) on State Route 100, crossing the White River, Rochester, Vermont","interactions":[],"lastModifiedDate":"2016-08-25T12:37:23","indexId":"ofr977","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-7","title":"Level II scour analysis for Bridge 144 (ROCHVT01000144) on State Route 100, crossing the White River, Rochester, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure ROCHVT01000144 on State Route 100 crossing the White River, Rochester, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including a quantitative analysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of a Level I scour investigation also are included in Appendix E of this report. A Level I investigation provides a qualitative geomorphic characterization of the study site. Information on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is found in Appendix D.
The site is in the Green Mountain section of the New England physiographic province in central Vermont. The 68.9-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is pasture with forest on the valley walls.
In the study area, the White River has a meandering channel with a slope of approximately 0.003 ft/ft, an average channel top width of 119 ft and an average channel depth of 4 ft. The predominant channel bed material is gravel and cobbles with a median grain size (D50) of 72.5 mm (0.238 ft). The geomorphic assessment at the time of the Level I and Level II site visit on July 22, 1996, indicated that the reach was laterally unstable due to a cut-bank present on the upstream left bank and wide point bars upstream and downstream in the vicinity of this site.
The State Route 100 crossing of the White Riveris a 103-ft-long, two-lane bridge consisting of one 101-foot steel-beam span (Vermont Agency of Transportation, written communication, March 8, 1995). The bridge is supported by vertical, concrete abutment walls with spill-through embankments in front of each abutment wall and no wingwalls. The channel is skewed approximately 10 degrees to the opening while the opening-skew-toroadway is 5 degrees.
The scour protection measures at the site are type-2 stone fill (less than 36 inches diameter) on the upstream left bank, both abutment spill-through embankments, and the downstream banks. There also is type-1 stone fill (less than 12 inches diameter) on the upstream right bank. The stone fill is continuous on both sides of the river in the vicinity of the bridge. Additional details describing conditions at the site are included in the Level II Summary and Appendices D and E.
Scour depths and rock rip-rap sizes were computed using the general guidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995). Total scour at a highway crossing is comprised of three components: 1) long-term streambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is the sum of the three components. Equations are available to compute depths for contraction and local scour and a summary of the results of these computations follows.
There was no computed contraction scour for the modelled flows. Abutment scour ranged from 6.9 to 10.9 ft. The worst-case abutment scour occurred at the incipient overtopping discharge, which was less than the 100-year discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particlesize distribution.
It is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, computed scour depths are evaluated in combination with other information including (but not limited to) historical performance during flood events, the geomorphic stability assessment, existing scour protection measures, and the results of the hydraulic analyses. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr977","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Boehmler, E.M., and Wild, E.C., 1997, Level II scour analysis for Bridge 144 (ROCHVT01000144) on State Route 100, crossing the White River, Rochester, Vermont: U.S. Geological Survey Open-File Report 97-7, iv, 50 p., https://doi.org/10.3133/ofr977.","productDescription":"iv, 50 p.","numberOfPages":"55","costCenters":[],"links":[{"id":169563,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr977.PNG"},{"id":279829,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0007/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Rochester","otherGeospatial":"White River","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.875,43.875 ], [ -72.875,44.0 ], [ -72.75,44.0 ], [ -72.75,43.875 ], [ -72.875,43.875 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b1ae4b07f02db6a82e1","contributors":{"authors":[{"text":"Boehmler, Erick M.","contributorId":96303,"corporation":false,"usgs":true,"family":"Boehmler","given":"Erick","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":240396,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Wild, Emily C. 0000-0001-6157-7629 ecwild@usgs.gov","orcid":"https://orcid.org/0000-0001-6157-7629","contributorId":1810,"corporation":false,"usgs":true,"family":"Wild","given":"Emily","email":"ecwild@usgs.gov","middleInitial":"C.","affiliations":[{"id":5081,"text":"Libraries","active":false,"usgs":true}],"preferred":false,"id":240395,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49872,"text":"ofr978 - 1997 - Level II scour analysis for Bridge 7 (WARRTH00010007) onTown Highway 1, crossing Freemans Brook, Warren, Vermont","interactions":[],"lastModifiedDate":"2014-01-07T10:55:12","indexId":"ofr978","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-8","title":"Level II scour analysis for Bridge 7 (WARRTH00010007) onTown Highway 1, crossing Freemans Brook, Warren, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nWARRTH00010007 on Town Highway 1 crossing Freeman Brook, Warren, Vermont \n(figures 1–8). A Level II study is a basic engineering analysis of the site, including a \nquantitative analysis of stream stability and scour (U.S. Department of Transportation, \n1993). Results of a Level I scour investigation also are included in Appendix E of this \nreport. A Level I investigation provides a qualitative geomorphic characterization of the \nstudy site. Information on the bridge, gleaned from Vermont Agency of Transportation \n(VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is \nfound in Appendix D.\nThe site is in the Green Mountain section of the New England physiographic province in \ncentral Vermont. The 6.45-mi2\n drainage area is in a predominantly rural and forested basin. \nIn the vicinity of the study site, the predominant surface cover is grass and trees with the \nexception of the upstream left overbank which is forest. The banks of the channel are tree \ncovered.\nIn the study area, Freeman Brook has an incised, straight channel with a slope of \napproximately 0.03 ft/ft, an average channel top width of 51 ft and an average channel \ndepth of 6 ft. The predominant channel bed material ranges from gravel to bedrock with a \nmedian grain size (D50) of 86.8 mm (0.285 ft). The geomorphic assessment at the time of \nthe Level I and Level II site visit on July 22, 1996 indicated that the reach was stable.\nThe Town Highway 1 crossing of Freeman Brook is a 64-ft-long, two-lane bridge \nconsisting of one 62-foot steel-beam span (Vermont Agency of Transportation, written \ncommunication, February 1, 1996). The bridge is supported by vertical, concrete abutments \nwith spill-through slopes. The channel is skewed approximately 25 degrees to the opening \nwhile the opening-skew-to-roadway is 30 degrees. \nThe only scour protection measure at the site was type-2 stone fill (less than 36 inches \ndiameter) along the entire length of the left and right abutments and along the downstream \nchannel banks. Additional details describing conditions at the site are included in the Level \nII Summary and Appendices D and E.\nScour depths and rock rip-rap sizes were computed using the general guidelines described \nin Hydraulic Engineering Circular 18 (Richardson and others, 1995). Total scour at a \nhighway crossing is comprised of three components: 1) long-term streambed degradation; \n2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) \nand; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is \nthe sum of the three components. Equations are available to compute depths for contraction \nand local scour and a summary of the results of these computations follows.\nThe computed contraction scour for all modelled flows was 0.0 feet. Abutment scour \nranged from 5.3 to 8.2 ft. The worst-case abutment scour occurred at the right abutment for \nthe incipient-overtopping discharge. Additional information on scour depths and depths to \narmoring are included in the section titled “Scour Results”. Scoured streambed elevations, \nbased on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the \nscour computed at the bridge is presented in figure 8. Scour depths were calculated \nassuming an infinite depth of erosive material and a homogeneous particle-size distribution. \nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr978","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Flynn, R.H., and Burns, R.L., 1997, Level II scour analysis for Bridge 7 (WARRTH00010007) onTown Highway 1, crossing Freemans Brook, Warren, Vermont: U.S. Geological Survey Open-File Report 97-8, iv, 52 p., https://doi.org/10.3133/ofr978.","productDescription":"iv, 52 p.","numberOfPages":"57","costCenters":[],"links":[{"id":169564,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr978.PNG"},{"id":279828,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0008/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Warren","otherGeospatial":"Freeman Brook","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.875,44.0 ], [ -72.875,44.125 ], [ -72.75,44.125 ], [ -72.75,44.0 ], [ -72.875,44.0 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b16e4b07f02db6a5728","contributors":{"authors":[{"text":"Flynn, Robert H. rflynn@usgs.gov","contributorId":2137,"corporation":false,"usgs":true,"family":"Flynn","given":"Robert","email":"rflynn@usgs.gov","middleInitial":"H.","affiliations":[{"id":405,"text":"NH/VT office of New England Water Science Center","active":true,"usgs":true}],"preferred":true,"id":240397,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Burns, Ronda L.","contributorId":71602,"corporation":false,"usgs":true,"family":"Burns","given":"Ronda","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":240398,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":50006,"text":"ofr97771 - 1997 - Level II scour analysis for Bridge 41 (ANDOVT00110041) on State Route 11, crossing the Middle Branch Williams River, Andover, Vermont","interactions":[],"lastModifiedDate":"2016-08-25T12:32:19","indexId":"ofr97771","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-771","title":"Level II scour analysis for Bridge 41 (ANDOVT00110041) on State Route 11, crossing the Middle Branch Williams River, Andover, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure ANDOVT00110041 on State Route 11 crossing the Middle Branch Williams River, Andover, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including a quantitative analysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of a Level I scour investigation also are included in Appendix E of this report. A Level I investigation provides a qualitative geomorphic characterization of the study site. Information on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is found in Appendix D.
The site is in the Green Mountain section of the New England physiographic province in southeastern Vermont. The 12.1-mi2 drainage area is in a predominantly rural and forested basin. In the vicinity of the study site, the surface cover is grass on the upstream right overbank while the immediate banks have dense woody vegetation. The upstream left overbank and downstream right overbank are brushland. The downstream left overbank is forested.
In the study area, the Middle Branch Williams River has an incised, sinuous channel with a slope of approximately 0.018 ft/ft, an average channel top width of 71 ft and an average bank height of 4 ft. The channel bed material ranges from gravel to boulders with a median grain size (D50) of 85.0 mm (0.279 ft). The geomorphic assessment at the time of the Level I and Level II site visit on September 10, 1996, indicated that the reach was laterally unstable due to a cut-bank present on the upstream right bank and a wide channel bar with vegetation in the upstream reach.
The State Route 11 crossing of the Middle Branch Williams River is a 46-ft-long, two-lane bridge consisting of a concrete 44-foot tee-beam span (Vermont Agency of Transportation, written communication, March 29, 1995). The opening length of the structure parallel to the bridge face is 42 ft. The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 35 degrees to the opening while the opening-skew-toroadway is zero degrees.
A scour hole 0.8 ft deeper than the mean thalweg depth was observed along the downstream end of the left abutment and downstream left wingwall during the Level I assessment. Type- 2 stone fill (less than 36 inches diameter) protects the upstream end of the upstream left wingwall, the downstream ends of the downstream left and right wingwalls and the downstream right road embankment. Type-3 stone fill protects the upstream end of the upstream right wingwall and the upstream right bank. Additional details describing conditions at the site are included in the Level II Summary and Appendices D and E.
Scour depths and recommended rock rip-rap sizes were computed using the general guidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995). In addition, the incipient roadway-overtopping discharge was determined and analyzed as another potential worst-case scour scenario. Total scour at a highway crossing is comprised of three components: 1) long-term streambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is the sum of the three components. Equations are available to compute depths for contraction and local scour and a summary of the results of these computations follows.
Contraction scour for all modelled flows ranged from 0.0 to 2.1 ft. The worst-case contraction scour occurred at the 500-year discharge. Abutment scour ranged from 11.1 to 18.7 ft. The worst-case abutment scour occurred at the 500-year discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution.
It is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, computed scour depths are evaluated in combination with other information including (but not limited to) historical performance during flood events, the geomorphic stability assessment, existing scour protection measures, and the results of the hydraulic analyses. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr97771","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Wild, E.C., and Hammond, R.E., 1997, Level II scour analysis for Bridge 41 (ANDOVT00110041) on State Route 11, crossing the Middle Branch Williams River, Andover, Vermont: U.S. Geological Survey Open-File Report 97-771, iv, 52 p., https://doi.org/10.3133/ofr97771.","productDescription":"iv, 52 p.","numberOfPages":"57","costCenters":[],"links":[{"id":176714,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97771.PNG"},{"id":279672,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0771/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Andover","otherGeospatial":"Williams River","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -73.125,44.375 ], [ -73.125,44.5 ], [ -73.0,44.5 ], [ -73.0,44.375 ], [ -73.125,44.375 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a61ab","contributors":{"authors":[{"text":"Wild, Emily C. 0000-0001-6157-7629 ecwild@usgs.gov","orcid":"https://orcid.org/0000-0001-6157-7629","contributorId":1810,"corporation":false,"usgs":true,"family":"Wild","given":"Emily","email":"ecwild@usgs.gov","middleInitial":"C.","affiliations":[{"id":5081,"text":"Libraries","active":false,"usgs":true}],"preferred":false,"id":240622,"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":240623,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49873,"text":"ofr971 - 1997 - Level II scour analysis for Bridge 92 (WSTOVT01000092) on State Highway 100, crossing the West River, Weston, Vermont","interactions":[],"lastModifiedDate":"2014-01-07T11:07:07","indexId":"ofr971","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-1","title":"Level II scour analysis for Bridge 92 (WSTOVT01000092) on State Highway 100, crossing the West River, Weston, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nWSTOVT01000092 on Vermont Highway 100 crossing the West River, Weston, Vermont \n(figures 1–8). A Level II study is a basic engineering analysis of the site, including a \nquantitative analysis of stream stability and scour (U.S. Department of Transportation, \n1993). Results of a Level I scour investigation also are included in Appendix E of this \nreport. A Level I investigation provides a qualitative geomorphic characterization of the \nstudy site. Information on the bridge, gleaned from Vermont Agency of Transportation \n(VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is \nfound in Appendix D.\nThe site is in the Green Mountain section of the New England physiographic province in \nsouth-central Vermont. The 32.7-mi2\n drainage area is in a predominantly rural and forested \nbasin. In the vicinity of the study site, the surface cover upstream of the bridge is primarily \nforest with pasture on the upstream left overbank. Upstream and downstream, the \nimmediate banks have brush and dense forest cover. Downstream of the bridge is forested.\nIn the study area, the West River has an incised, sinuous channel with a slope of \napproximately 0.006 ft/ft, an average channel top width of 111 ft and an average channel \ndepth of 3 ft. The predominant channel bed material is very coarse gravel and cobbles with \na median grain size (D50) of 67.7 mm (0.222 ft). The geomorphic assessment at the time of \nthe Level I and Level II site visit on August 19, 1996 indicated that the reach was laterally \nunstable based on the fine bank material, sinuosity of the stream, point bars and cutbanks.\nThe state highway 100 crossing of the West River is a 113-ft-long, two-lane bridge \nconsisting of one 110-foot steel-beam span (Vermont Agency of Transportation, written \ncommunication, March 31, 1995). The bridge is supported by vertical, concrete abutments \nwithout wingwalls. The channel is skewed approximately 40 degrees to the opening while \nthe opening-skew-to-roadway is 25 degrees. \nThe only scour protection measure at the site was type-2 stone fill (less than 36 inches \ndiameter) along the entire base length of the left and right abutments. Additional details \ndescribing conditions at the site are included in the Level II Summary and Appendices D \nand E.\nScour depths and rock rip-rap sizes were computed using the general guidelines described \nin Hydraulic Engineering Circular 18 (Richardson and others, 1995). Total scour at a \nhighway crossing is comprised of three components: 1) long-term streambed degradation; \n2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) \nand; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is \nthe sum of the three components. Equations are available to compute depths for contraction \nand local scour and a summary of the results of these computations follows.\nContraction scour for all modelled flows ranged from 0.4 to 2.1 ft. The worst-case \ncontraction scour occurred at the 500-year discharge. Abutment scour ranged from 8.4 to \n30.7 ft. The worst-case abutment scour occurred at the 500-year discharge along the left \nabutment. Additional information on scour depths and depths to armoring are included in \nthe section titled “Scour Results”. Scoured-streambed elevations, based on the calculated \nscour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the \nbridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of \nerosive material and a homogeneous particle-size distribution. \nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr971","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Flynn, R.H., and Burns, R.L., 1997, Level II scour analysis for Bridge 92 (WSTOVT01000092) on State Highway 100, crossing the West River, Weston, Vermont: U.S. Geological Survey Open-File Report 97-1, iv, 48 p., https://doi.org/10.3133/ofr971.","productDescription":"iv, 48 p.","numberOfPages":"53","costCenters":[],"links":[{"id":169565,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr971.PNG"},{"id":279826,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0001/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Weston","otherGeospatial":"West River","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.875,43.25 ], [ -72.875,43.375 ], [ -72.75,43.375 ], [ -72.75,43.25 ], [ -72.875,43.25 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b16e4b07f02db6a55ce","contributors":{"authors":[{"text":"Flynn, Robert H. rflynn@usgs.gov","contributorId":2137,"corporation":false,"usgs":true,"family":"Flynn","given":"Robert","email":"rflynn@usgs.gov","middleInitial":"H.","affiliations":[{"id":405,"text":"NH/VT office of New England Water Science Center","active":true,"usgs":true}],"preferred":true,"id":240399,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Burns, Ronda L.","contributorId":71602,"corporation":false,"usgs":true,"family":"Burns","given":"Ronda","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":240400,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49993,"text":"ofr97753 - 1997 - Level II scour analysis for Bridge 45 (BRNETH00070045) on Town Highway 7, crossing the Stevens River, Barnet, Vermont","interactions":[],"lastModifiedDate":"2013-12-17T13:29:28","indexId":"ofr97753","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-753","title":"Level II scour analysis for Bridge 45 (BRNETH00070045) on Town Highway 7, crossing the Stevens River, Barnet, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nBRNETH00070045 on Town Highway 7 crossing the Stevens River, Barnet, Vermont \n(figures 1–8). A Level II study is a basic engineering analysis of the site, including a \nquantitative analysis of stream stability and scour (U.S. Department of Transportation, \n1993). Results of a Level I scour investigation also are included in Appendix E of this \nreport. A Level I investigation provides a qualitative geomorphic characterization of the \nstudy site. Information on the bridge, gleaned from Vermont Agency of Transportation \n(VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is \nfound in Appendix D.
\nThe site is in the New England Upland section of the New England physiographic province \nin east-central Vermont. The 41.5-mi2\n drainage area is in a predominantly rural and forested \nbasin. In the vicinity of the study site, the surface cover is forest upstream and pasture \ndownstream of the bridge while the immediate banks have dense woody vegetation.
\nIn the study area, the Stevens River has an incised, sinuous channel with a slope of \napproximately 0.02 ft/ft, an average channel top width of 100 ft and an average bank height \nof 17 ft. The channel bed material ranges from gravel to boulder with a median grain size \n(D50) of 105 mm (0.344 ft). The geomorphic assessment at the time of the Level I and Level \nII site visit on August 22, 1995, indicated that the reach was stable.
\nThe Town Highway 7 crossing of the Stevens River is a 37-ft-long, two-lane bridge \nconsisting of one 34-foot concrete slab span (Vermont Agency of Transportation, written \ncommunication, March 16, 1995). The opening length of the structure parallel to the bridge \nface is 33 ft. The bridge is supported by vertical, concrete abutments with wingwalls. The \nchannel is skewed approximately 10 degrees to the opening while the opening-skew-to-roadway is 20 degrees.
\nThe only scour protection measure at the site was type-2 stone fill (less than 36 inches \ndiameter) along the entire left and right abutments, upstream and downstream wingwalls, \nand upstream and downstream banks. Additional details describing conditions at the site are \nincluded in the Level II Summary and Appendices D and E.
\nScour depths and recommended rock rip-rap sizes were computed using the general \nguidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1995) \nfor the 100- and 500-year discharges. In addition, the incipient roadway-overtopping \ndischarge is determined and analyzed as another potential worst-case scour scenario. Total \nscour at a highway crossing is comprised of three components: 1) long-term streambed \ndegradation; 2) contraction scour (due to accelerated flow caused by a reduction in flow \narea at a bridge) and; 3) local scour (caused by accelerated flow around piers and \nabutments). Total scour is the sum of the three components. Equations are available to \ncompute depths for contraction and local scour and a summary of the results of these \ncomputations follows.
\nContraction scour for all modelled flows ranged from 0.8 to 5.4 ft. The worst-case \ncontraction scour occurred at the incipient roadway-overtopping discharge, which was \ngreater than the 100-year discharge. Left abutment scour ranged from 21.8 to 28.6 ft. The \nworst-case left abutment scour occurred at the 500-year discharge. Right abutment scour \nranged from 14.6 to 17.4 ft. The worst-case right abutment scour occurred at the incipient \nroadway-overtopping discharge. Additional information on scour depths and depths to \narmoring are included in the section titled “Scour Results”. Scoured-streambed elevations, \nbased on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the \nscour computed at the bridge is presented in figure 8. Scour depths were calculated \nassuming an infinite depth of erosive material and a homogeneous particle-size distribution.
\nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr97753","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Ivanoff, M.A., and Hammond, R.E., 1997, Level II scour analysis for Bridge 45 (BRNETH00070045) on Town Highway 7, crossing the Stevens River, Barnet, Vermont: U.S. Geological Survey Open-File Report 97-753, iv, 51 p., https://doi.org/10.3133/ofr97753.","productDescription":"iv, 51 p.","numberOfPages":"56","costCenters":[],"links":[{"id":176840,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr97753.GIF"},{"id":279685,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0753/report.pdf"}],"scale":"25000","country":"United States","state":"Vermont","city":"Barnet","otherGeospatial":"Stevens River","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.25,44.25 ], [ -72.25,44.375 ], [ -72.0,44.375 ], [ -72.0,44.25 ], [ -72.25,44.25 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a60fa","contributors":{"authors":[{"text":"Ivanoff, Michael A.","contributorId":27105,"corporation":false,"usgs":true,"family":"Ivanoff","given":"Michael","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":240599,"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":240600,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":49874,"text":"ofr979 - 1997 - Level II scour analysis for Bridge 34 (SHERUS00040034) on U.S. Highway 4, crossing the Ottauquechee River, Sherburne, Vermont","interactions":[],"lastModifiedDate":"2014-01-07T11:02:29","indexId":"ofr979","displayToPublicDate":"1994-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"97-9","title":"Level II scour analysis for Bridge 34 (SHERUS00040034) on U.S. Highway 4, crossing the Ottauquechee River, Sherburne, Vermont","docAbstract":"This report provides the results of a detailed Level II analysis of scour potential at structure \nSHERUS00040034 on US Route 4 crossing the Ottauquechee River, Sherburne, Vermont \n(figures 1–8). A Level II study is a basic engineering analysis of the site, including a \nquantitative analysis of stream stability and scour (U.S. Department of Transportation, \n1993). Results of a Level I scour investigation also are included in Appendix E of this \nreport. A Level I investigation provides a qualitative geomorphic characterization of the \nstudy site. Information on the bridge, gleaned from Vermont Agency of Transportation \n(VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is \nfound in Appendix D.\nThe site is in the Green Mountain section of the New England physiographic province in \ncentral Vermont. The 25.8-mi2\n drainage area is in a predominantly rural and forested basin. \nIn the vicinity of the study site, the surface cover is pasture upstream of the bridge while the \nimmediate banks have dense woody vegetation. Downstream of the bridge, the banks are \nforested.\nIn the study area, the Ottauquechee River has an incised, straight channel with a slope of \napproximately 0.028 ft/ft, an average channel top width of 66 ft and an average channel \ndepth of 5 ft. The channel bed material ranges from gravel to boulder with a median grain \nsize (D50) of 118.1 mm (0.387 ft). The geomorphic assessment at the time of the Level I and \nLevel II site visit on September 25, 1995, indicated that the reach was stable.\nThe US Route 4 crossing of the Ottauquechee River is a 187-ft-long, two-lane bridge \nconsisting of three steel-beam spans (Vermont Agency of Transportation, written \ncommunication, March 14, 1995). The bridge is supported by vertical, concrete abutments \nabove spill-through stone fill (< 36 inches diameter). The channel is skewed approximately \n60 degrees to the opening while the opening-skew-to-roadway is 60 degrees. Additional \ndetails describing conditions at the site are included in the Level II Summary and \nAppendices D and E.\nScour depths and rock rip-rap sizes were computed using the general guidelines described \nin Hydraulic Engineering Circular 18 (Richardson and others, 1995). Total scour at a \nhighway crossing is comprised of three components: 1) long-term streambed degradation; \n2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) \nand; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is \nthe sum of the three components. Equations are available to compute depths for contraction \nand local scour and a summary of the results of these computations follows.\nContraction scour for all modelled flows was 0.0 ft. Abutment scour ranged from 4.7 to 7.4 \nft. The worst-case abutment scour occurred at the left abutment for the 500-year discharge. \nPier scour ranged from 7.5 to 11.4 ft. The worst-case pier scour occurred at the incipientovertopping discharge. Additional information on scour depths and depths to armoring are \nincluded in the section titled “Scour Results”. Scoured-streambed elevations, based on the \ncalculated scour depths, are presented in tables 1 and 2. A cross-section of the scour \ncomputed at the bridge is presented in figure 8. Scour depths were calculated assuming an \ninfinite depth of erosive material and a homogeneous particle-size distribution. \nIt is generally accepted that the Froehlich equation (abutment scour) gives “excessively \nconservative estimates of scour depths” (Richardson and others, 1995, p. 47). Usually, \ncomputed scour depths are evaluated in combination with other information including (but \nnot limited to) historical performance during flood events, the geomorphic stability \nassessment, existing scour protection measures, and the results of the hydraulic analyses. \nTherefore, scour depths adopted by VTAOT may differ from the computed values \ndocumented herein.","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Pembroke, NH","doi":"10.3133/ofr979","collaboration":"Prepared in cooperation with Vermont Agency of Transportation and Federal Highway Administration","usgsCitation":"Flynn, R.H., and Severance, T., 1997, Level II scour analysis for Bridge 34 (SHERUS00040034) on U.S. Highway 4, crossing the Ottauquechee River, Sherburne, Vermont: U.S. Geological Survey Open-File Report 97-9, iv, 51 p., https://doi.org/10.3133/ofr979.","productDescription":"iv, 51 p.","numberOfPages":"56","costCenters":[],"links":[{"id":169566,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/ofr979.PNG"},{"id":279827,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/1997/0009/report.pdf"}],"scale":"24000","country":"United States","state":"Vermont","city":"Sherburne","otherGeospatial":"Ottauquechee River","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -72.875,43.5 ], [ -72.875,43.625 ], [ -72.75,43.625 ], [ -72.75,43.5 ], [ -72.875,43.5 ] ] ] } } ] }","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b17e4b07f02db6a6507","contributors":{"authors":[{"text":"Flynn, Robert H. rflynn@usgs.gov","contributorId":2137,"corporation":false,"usgs":true,"family":"Flynn","given":"Robert","email":"rflynn@usgs.gov","middleInitial":"H.","affiliations":[{"id":405,"text":"NH/VT office of New England Water Science Center","active":true,"usgs":true}],"preferred":true,"id":240401,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Severance, Timothy","contributorId":104927,"corporation":false,"usgs":true,"family":"Severance","given":"Timothy","email":"","affiliations":[],"preferred":false,"id":240402,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ]}