Type Curves for a Slug Test in an Infinitely or Semi-infinitely Thick Aquifer
Type curves are provided for a slug test in an infinitely or semi-infinitely thick aquifer, the latter with the single confining layer immediately above or immediately below the well....

Aquifer Measurements at Different Scales
Multilevel slug test data from five wells in a confined, sandy aquifer were analyzed to obtain an estimate of the vertical variation of the horizontal hydraulic conductivity, K(z). Hydraulic...

Application of Tracer Tests in Groundwater Remediation Design
Recent advances in the area of field testing for the quantification of hydraulic conductivity have resulted in improved site characterization of aquifer hydraulics and greater reliability...

Stepped Spillway Design for Flow Over Embankments
Many embankment dams have been identified as unable to pass their design flows without failure due to overtopping. The U.S. Bureau of Reclamation (Reclamation) is currently at the forefront...

Modeling and Field Experiments for Tracer Gas Tests
Numerical modeling and field experiments were used to extend the tracer gas technique for determining surface gas transfer rates to shallow bays. Two-dimensional modeling was used to investigate...

Hatchie River and Schoharie Creek Bridge Failures
Within a 2-year period two large bridges collapsed into flooded rivers resulting in a total of 18 people plunging to their deaths. Both bridges had been inspected by probing, but had not...

Bridge Scour Vulnerability Assessment
Although the failure of the New York Throughway bridge over Schoharie Creek in 1987 has focused national attention on scour related failures, other failures reinforce the need for implementing...

Bridge Inspections Related to Bridge Scour
The failure of the Silver Bridge over the Ohio River in Point Pleasant, West Virginia, on December 15, 1967 resulted in the establishment of the National Bridge Inspection Standards (NBIS)...

A National Bridge Scour Data Collection Program
A study to collect and analyze field measurements of bridge scour is being conducted by the U.S. Geological Survey in cooperation with the Federal Highway Administration. The primary objective...

Modeling of Wetland Hydrodynamics and Transport in Coastal Louisiana
Modeling of hydraulics and transport of large wetland systems poses critical decisions between resolution of the complex geometry of a wetland and the testing required to meet study goals....

The Design of Scour-Safe Bridges
Two new highway systems, the East Papago and the Pima freeways, are currently under design and construction within the Phoenix, Arizona, metropolitan area. Both of these highways will...

Scour Measuring and Monitoring Equipment for Bridges
The National Cooperative Highway Research program (NCHRP), through the Transportation Research Board (TRB) of the National Academy of Sciences, is currently sponsoring a research effort...

Bridge Scour and Stream Instability Countermeasures
Stream instability is characterized by lateral or vertical instability. Such instability has led to the failure of bridges and loss of life. Lateral instability is caused by lateral migration...

Bridge Scour Research Needs
This paper presents a summary of the Federal Highway Administration (FHWA) priority research emphasis on bridge scour, sedimentation, and stream stability problems. The most persistent...

Set-Down in a Tidal Embayment
A mean water level in tidal bays and estuaries that is higher than the ocean mean water level (set-up) is a fairly common occurrence. Set-down of the mean water level can be shown to be...

Experimental Model Study of Over and Under Baffles
A hydraulic model study of a chlorine mixing channel was conducted at the Hydraulic Research Laboratory of the City of Los Angeles. An arrangement of over-under baffles was used to facilitate...

Ultrasonic Velocity Meter Used in Stream Gaging
Many streams and canals in Florida are affected by tides or control structures and experience very low flow velocities at times. For example, the St. Johns River in northeastern Florida...

Computerized Hydraulic Modeling?A Case Study
A hydraulic model study is being conducted at the Alden Research Laboratory, Inc. (ARL), to study the effects of adding a hydroelectric generating station at the site of an existing lock...

Probabilistic Aspects of Hydroproject Maintenance
A survey of operation and maintenance personnel in the hydraulic structures sector was conducted to learn about the present maintenance approach and the perception of the probabilistic...

Model Studies on Local Scour
In this investigation, the scaling procedure of a scour model in the laboratory has been indicated. The results have been compared with the prototype data....

 

 

 

 

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