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...

Numerical Models of Phytoplankton Dynamics for Shallow Estuaries
The relationship between physical processes and phytoplankton population dynamics in coastal ocean waters is a complicated issue largely because of the shallowness of the water column,...

Estimating Pier Scour with Artificial Neural Networks
This paper describes the use of artificial neural network (ANN) analysis as a computing device for estimating scour at bridge piers. The neural network presented here is based on 515 sets...

An Artificial Neural Network for Computing Sediment Transport
This paper describes the use of artificial neural network (ANN) analysis as a computing device for estimating sediment transport in open channels. The application was developed from 1,455...

The Control and Monitoring of Local Scour at Bridge Piers
A series of flume experiments revealed a possible method of reducing local river bed scour at bridge piers, thereby, reducing the risk of bridge failure. Three prototype schemes were installed...

Comparison of Theoretical and Historical Scour
As part of scour assessments at approximately 120 stream crossings on the New York State Thruway, subsurface investigations were performed at all structures and, in some instances, locations...

A 2-D Lake Model with Artificial Destratification
Artificial destratification of lakes and reservoirs is used to influence a variety of water quality parameters. It relies on localized, vertical mixing of the water column and the subsequent...

Stratification Models Sensitivity to Solar Radiation Data
A one-dimensional water quality model (WESTEX model) for simulation of thermal stratification is used to test the performance of such models related to hydrometeorological input data....

Selective Withdrawal in a Rotating Stratified Fluid
In this paper we consider the axisymmetric flow of a rotating stratified fluid into a point sink. Linear analysis of the initial value problem of flow of a linearly stratified fluid into...

Pressure Relief Under Hydraulic Jump Stilling Basins
Gravity drainage cannot be used for any portion of a structure located below tailwater level. Yet, drainage of this area may be required to relieve sub-floor pressures and reduce the risk...

General Implicit Representation of Hydraulic Structures in Numerical Flow Models
Effects of hydraulic structures (such as culverts, bridge openings, or gates) can be simulated in numerical surface-water-flow models. Generally the scale and dimension of the numerical...

Modeling the Impacts of Plankton Entrainment in a Tropical Bay
As part of the permitting for a coal-fired power plant, several enhancements were made to the two-dimensional flow and transport models TEA and ELA that allowed for the quantification...

Drag Characteristics of Coarse Sediment in Clay Suspensions
Drag characteristics of spherical particles in clay suspensions, such as coarse sediment in hyperconcentrated flows, has been analyzed by using a limited data available in the literature....

Shape Effect on Bed-Load Transport in Pipes
The nature of part-full flows in pipe sewers produces different channel shapes resulting in non-uniform shear stress distribution on the wetted perimeter. New experimental data were utilized...

Regulation of Flow Downstream of Weirs
Reregulation weirs are one means adopted by the Tennessee Valley Authority (TVA) to provide continuous improved minimum flow and wetted area for aquatic life downstream if hydroprojects...

Flow Resistance Properties of Flexible Linings
Flow resistance for flexible channel linings is a function of the relative roughness of the lining in accordance with boundary-layer principles. As with vegetation, flexible linings have...

Storm Drainage Channel Rehabilitation
30 km (19 miles) of existing concrete lines storm drainage channels were studied due to repeated failures. Alternate failures causes were hypothesized and evaluated. Physical testing was...

Tetrapods as a Scour Countermeasure
Few materials have been studied for their effectiveness in protecting bridge piers and abutments from local scour other than riprap. Recent research conducted at the FHWA research facility...

 

 

 

 

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