Mechanics of Riprap Movement in Tidal Flow
This analysis emphasizes the need to obtain data on the size and shape of riprap pieces as a function of movement, data which are surprisingly difficult to obtain from published studies....
Comparison of Two Methods of Screening Bridges for Scour
Scour evaluations were performed for large numbers of bridges in two separate studies in New York and New Jersey. The two studies used different screening methods for identifying high-priority...
Case Studies of Bridge Scour in Western New York
As part of the New York State Thruway Authority's bridge hydrologic/hydraulic evaluation program, 63 structures over 42 stream crossings in western New York were assessed for scour potential...
Risk Analysis of River Bridge Failure
The proposed procedure to determine the risk of river bridge failure is based on observations and analysis of river bridge failure data of more than 300 U.S. bridges, 180 South African...
Quantification of Uncertainties in a Water Quality Model with Application to the Sacramento-San Joaquin Delta
A methodology is described that allows a quantitative verification of water quality models. The methodology provides a quantitative analysis of model accuracy that takes into account different...
Using Threat to Life Studies to Guide Dam Safety Decisions
Ensuring that Bureau of Reclamation (Reclamation) dams do not present unacceptable risks to public safety, prosperity, and welfare serves as a primary objective of Reclamation's Safety...
Reclamation's Design Process of Early Warning Systems for Dam Safety
This paper discusses the Bureau of Reclamation's process for designing the detection and decision making components of an Early Warning System (EWS) for dams with hydrologic deficiencies....
Emergency Action Plan
Although most dam owners have a high level of confidence in the structures they own and are certain their dams will not fail, the Bureau of Reclamation (Reclamation) included, history...
U.S. Geological Survey Bedload Sampling Policy
During the late 1960's, the U.S. Geological Survey's (USGS) Water Resources Division (WRD) developed the Helley-Smith bedload sampler. Since then, the USGS and the Technical Committee...
The Fallacy of Local Abutment Scour Equations
Existing laboratory model studies for quantifying local abutment scour deviate significantly from conditions typically found in the field. This has resulted in predictive local abutment...
Scour Prediction Model at Bridge Abutments
A model to predict local abutment scour is presented. The model is based on a large number of laboratory experiments over the past half century. The dependent variable, a ratio that includes...
Bridge Abutment Scour in a Floodplain
Recent bridge failures due to pier and abutment scour have reinforced the need for better methods of scour prediction. This paper addresses the problem of prediction of clear-water scour...
Plans for a Sensitivity Analysis of Bridge-Scour Computations
Plans for an analysis of the sensitivity of Level 2 bridge-scour computations are described. Cross-section data from 15 bridge sites in Texas are modified to reflect four levels of field...
Density Currents in Pollutant Transport and Mixing
A buoyant spreading model for the current-advected plume is formulated including several distinct mechanisms: convective spreading, interfacial friction spreading, entrainment at the density...
Bed Sediments Size Changes, Atchafalaya River
During low flows of 1989 and 1991, we collected bed sediment samples from the thalwegs of the Mississippi River from Cairo, Illinois, to Head of Passes and along the Atchafalaya River...
Bank Stability Analyses Versus Field Observations
The concept and process of stream bank stabilization design through the development and use of limiting stability curves for the comparison of existing bank height/angle combinations to...
Effect of Grain Size on Sediment Transport Calculations
The U.S. Army Corps of Engineers is currently developing a `Hydraulic Design Package for Flood Control Channels' (SAM). SAM is capable of computing sediment rating curves and stable channel...
Economics of Floods, Scour, and Bridge Failures
Hydraulic events occur more often and account for more losses than any other natural disaster. The damage inflicted on our nation's highway facilities during these events not only results...
Mixing Characteristics of a Transitional Stratified Two-Layer Flow
Small scale structures in a stably stratified two-layer flow are investigated. The flow configuration has the initial velocity interface displaced with respect to the density interface....
Video Analysis of Gravel Saltation
Experimental results concerning saltation characteristics of gravel particles in a movable bed channel are analyzed by using video imaging techniques. Ensemble averaged values of saltation...
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