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Book Data Base for Assessment of Streambed Scour and Channel Instability at Selected Bridges in Indiana 1991 95

Download or read book Data Base for Assessment of Streambed Scour and Channel Instability at Selected Bridges in Indiana 1991 95 written by Mark S. Hopkins and published by . This book was released on 1997 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book New Publications of the U S Geological Survey

Download or read book New Publications of the U S Geological Survey written by and published by . This book was released on 1998 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Publications of the Geological Survey

Download or read book Publications of the Geological Survey written by Geological Survey (U.S.) and published by . This book was released on 1998 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Field Observations and Evaluations of Streambed Scour at Bridges

Download or read book Field Observations and Evaluations of Streambed Scour at Bridges written by U. S. Department Of Transportation and published by CreateSpace. This book was released on 2015-03-12 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bridge piers and highway embankments leading to a bridge often obstruct the flow of floodwaters, causing an increase in velocity and the development of vortices. The increased velocity and vortices often cause scour near the bridge foundations. The damage to and failure of bridges caused by scour are problems of national concern. This report describes the results of the second USGS national field-data collection and analysis study on scour at bridges, funded by FHWA. The database originally developed during the first national study has been enhanced and many scour measurements added, including measurements of abutment and contraction scour. Sufficient local pier scour data are now available to permit a detailed analysis of local pier scour. Scour depths computed from published pier scour equations are compared to the field measurements. Many commonly cited dimensionless variables believed to control the depth of scour are evaluated and compared with equations developed from laboratory data. The effect of the size and gradation of the bed material on the depth of scour is investigated, and a correction factor for the HEC-18 pier scour equation is proposed. Available data are insufficient to permit a detailed investigation of contraction and abutment scour; however, some basic comparisons and qualitative observations are presented on the basis of a review of the literature. The results of scour analyses for two contracted bridges are compared with real-time field data.

Book Evaluation of Scour at Selected Bridge Sites in Indiana

Download or read book Evaluation of Scour at Selected Bridge Sites in Indiana written by Robert Lyle Miller and published by . This book was released on 1996 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Assessment of Streambed Scour at Bridges in Indiana

Download or read book Assessment of Streambed Scour at Bridges in Indiana written by Gary Bennett and published by . This book was released on 1997 with total page 1 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Evaluation of Streambed Scour at Bridges Over Tidal Waterways in Alaska

Download or read book Evaluation of Streambed Scour at Bridges Over Tidal Waterways in Alaska written by Jeffrey Conaway and published by Createspace Independent Publishing Platform. This book was released on 2014-07-11 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The potential for streambed scour was evaluated at 41 bridges that cross tidal waterways in Alaska. These bridges are subject to several coastal and riverine processes that have the potential, individually or in combination, to induce streambed scour or to damage the structure or adjacent channel. The proximity of a bridge to the ocean and water-surface elevation and velocity data collected over a tidal cycle were criteria used to identify the flow regime at each bridge, whether tidal, riverine, or mixed, that had the greatest potential to induce streambed scour. Water-surface elevations measured through at least one tide cycle at 32 bridges were correlated to water levels at the nearest tide station. Asymmetry of the tidal portion of the hydrograph during the outgoing tide at 12 bridges indicated that riverine flows were stored upstream of the bridge during the tidal exchange. This scenario results in greater discharges and velocities during the outgoing tide compared to those on the incoming tide. Velocity data were collected during outgoing tides at 10 bridges that experienced complete flow reversals, and measured velocities during the outgoing tide exceeded the critical velocity required to initiate sediment transport at three sites. The primary risk for streambed scour at most of the sites considered in this study is from riverine flows rather than tidal fluctuations. A scour evaluation for riverine flow was completed at 35 bridges. Scour from riverine flow was not the primary risk for six tidally-controlled bridges and therefore not evaluated at those sites. Field data including channel cross sections, a discharge measurement, and a water-surface slope were collected at the 35 bridges. Channel instability was identified at 14 bridges where measurable scour and or fill were noted in repeated surveys of channel cross sections at the bridge. Water-surface profiles for the 1-percent annual exceedance probability discharge were calculated by using the Hydrologic Engineering Center's River Analysis System model, and scour depths were calculated using methods recommended by the Federal Highway Administration. Computed contraction-scour depths were greater than 2.0 feet at five bridges and computed pier-scour depths were 4.0 feet or greater at 15 bridges. The potential for streambed scour by both coastal and riverine processes at the bridges considered in this study were evaluated, ranked, and summed to determine a cumulative risk factor for each bridge. Possible factors that could mitigate the scour risks were investigated at 22 bridges that had high individual or cumulative rankings. Mitigating factors such as piers founded in bedrock, deep pier foundations relative to scour depths, and lack of observed scour during field measurements were documented for 13 sites, but additional study and monitoring is needed to better quantify the streambed scour potential for nine sites. Three bridges prone to being affected by storm surges will require more data collection and possibly complex hydrodynamic modeling to accurately quantify the streambed scour potential. Continuous monitoring of water-surface and streambed elevation at one or more piers is needed for two bridges to better understand the tidal and riverine influences on streambed scour.

Book Evaluation of Streambed Scour at Bridges Over Tidal Waterways in Alaska

Download or read book Evaluation of Streambed Scour at Bridges Over Tidal Waterways in Alaska written by Jeffrey Scott Conaway and published by CreateSpace. This book was released on 2012 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: The potential for streambed scour was evaluated at 41 bridges that cross tidal waterways in Alaska. These bridges are subject to several coastal and riverine processes that have the potential, individually or in combination, to induce streambed scour or to damage the structure or adjacent channel. The proximity of a bridge to the ocean and water-surface elevation and velocity data collected over a tidal cycle were criteria used to identify the flow regime at each bridge, whether tidal, riverine, or mixed, that had the greatest potential to induce streambed scour. Water-surface elevations measured through at least one tide cycle at 32 bridges were correlated to water levels at the nearest tide station. Asymmetry of the tidal portion of the hydrograph during the outgoing tide at 12 bridges indicated that riverine flows were stored upstream of the bridge during the tidal exchange. This scenario results in greater discharges and velocities during the outgoing tide compared to those on the incoming tide. Velocity data were collected during outgoing tides at 10 bridges that experienced complete flow reversals, and measured velocities during the outgoing tide exceeded the critical velocity required to initiate sediment transport at three sites. The primary risk for streambed scour at most of the sites considered in this study is from riverine flows rather than tidal fluctuations. A scour evaluation for riverine flow was completed at 35 bridges. Scour from riverine flow was not the primary risk for six tidally-controlled bridges and therefore not evaluated at those sites. Field data including channel cross sections, a discharge measurement, and a water-surface slope were collected at the 35 bridges. Channel instability was identified at 14 bridges where measurable scour and or fill were noted in repeated surveys of channel cross sections at the bridge. Water-surface profiles for the 1-percent annual exceedance probability discharge were calculated by using the Hydrologic Engineering Center's River Analysis System model, and scour depths were calculated using methods recommended by the Federal Highway Administration. Computed contraction-scour depths were greater than 2.0 feet at five bridges and computed pier-scour depths were 4.0 feet or greater at 15 bridges. The potential for streambed scour by both coastal and riverine processes at the bridges considered in this study were evaluated, ranked, and summed to determine a cumulative risk factor for each bridge. Possible factors that could mitigate the scour risks were investigated at 22 bridges that had high individual or cumulative rankings. Mitigating factors such as piers founded in bedrock, deep pier foundations relative to scour depths, and lack of observed scour during field measurements were documented for 13 sites, but additional study and monitoring is needed to better quantify the streambed scour potential for nine sites. Three bridges prone to being affected by storm surges will require more data collection and possibly complex hydrodynamic modeling to accurately quantify the streambed scour potential. Continuous monitoring of water-surface and streambed elevation at one or more piers is needed for two bridges to better understand the tidal and riverine influences on streambed scour.

Book Stream Instability Bridge Scour and Countermeasures A Field Guide for Bridge Inspectors

Download or read book Stream Instability Bridge Scour and Countermeasures A Field Guide for Bridge Inspectors written by Transportation Dept., Federal Highway Administration and published by Government Printing Office. This book was released on with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt: FHWA Publication No. FHWA-NHI-08-0106. February 2009. Explains the behavior of rivers in order to recognize changing conditions associated with unstable streams or scour at bridge foundations that may threaten the stability of the bridge. Provides tips and guidance on what to look for with regard to both stream instability, including lateral instability, degradation, and aggradation, and scour at bridges, including contraction scour, pier scour, and abutment scour. Also covered are plans of action and countermeasures, such as monitoring, flood watches, bridge closures, and river training countermeasures.

Book Bridge Scour and Stream Instability Countermeasures

Download or read book Bridge Scour and Stream Instability Countermeasures written by U.s. Department of Transportation and published by CreateSpace. This book was released on 2015-03-10 with total page 254 pages. Available in PDF, EPUB and Kindle. Book excerpt: This publication identifies and provides design guidelines for bridge scour and stream instability countermeasures that have been implemented by various State departments of transportation (DOTs) in the United States. Countermeasure experience, selection, and design guidance are consolidated from other FHWA publications in this document to support a comprehensive analysis of scour and stream instability problems and provide a range of solutions to those problems. Selected innovative countermeasure concepts and guidance derived from practice outside the United States are introduced. Management strategies and guidance for developing a Plan of Action for scour critical bridges are outlined, and guidance is provided for scour monitoring using portable and fixed instrumentation. The results of recently completed National Cooperative Highway Research Program (NCHRP) projects are incorporated in the design guidance, including: countermeasures to protect bridge piers and abutments from scour; riprap design criteria, specifications, and quality control; and environmentally sensitive channel and bank protection measures. This additional material required expanding HEC-23 to two volumes. Volume 1 now contains a complete chapter on riprap design, specifications, and quality control as well as an expanded chapter on biotechnical countermeasures. The guidance on scour monitoring instrumentation has been updated and now includes additional installation case studies. Volume 2 contains 19 detailed design guidelines grouped into six categories, including countermeasures for: (1) stream instability (2) streambank and roadway embankment protection, (3) bridge pier protection, (4) abutment protection, (5) filter design, and (6) special applications.

Book Monitoring Scour Critical Bridges

Download or read book Monitoring Scour Critical Bridges written by Beatrice E. Hunt and published by Transportation Research Board. This book was released on 2009 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt: