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...

Top Width of Pier Scour Holes in Free and Pressure Flow
The maximum top width of the local scour holes at piers is shown to be a simple function of the scour depth and the angle of repose of the bed material in water. Knowledge of the top width...

Preliminary Studies of Pressure Flow Scour
Bridges that become inundated during floods have slightly pressurized flow that impacts bridge piers and creates an aggravated scour condition. Results of two preliminary laboratory studies...

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...

Scour Around Bridge Piers in Oklahoma Streams in 1986
Historically, Oklahoma has received many severe rainfall and flooding events due to hurricanes hitting the coast of Florida and moving to the Gulf Coast area. One such event occurred during...

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...

n Values for Shallow Flow in Rough Channels
Manning's friction factor n has been developed from flume data for very shallow open channel flow in a high-gradient channel with large bed material. n values are presented as a function...

An Experimental Study of Bivalve Siphonal Jets in a Turbulent Boundary Layer Crossflow
We conducted experiments in a laboratory flume to study the interaction of bivalve siphonal jets with the turbulent boundary layer which forms in the benthic region of shallow estuaries....

Sediment Disposal and Transport in Central SF Bay
The relocation of dredged material from navigation channels in the Francisco Bay is crucial to the movement of deep-draft shipping and shallow-draft recreational vessels. The margins of...

McCormick Bridge Scour Evaluation?A Case Study of a Tidal Bridge
Although the Federal Highway Authority has implemented procedures for bridge scour analysis in their HEC-18 publication, they do not indicate a procedure for scour depth determination...

A Tidal Inlet Bridge Scour Assessment Model
Undermining of bridge structures constructed in tidal inlets is a common problem. Scour mechanisms in tidal inlets are often complex combinations of local contraction and regional tidal...

Fish Screen Developments, Columbia River Dams
This paper describes developments to date for a fish diversion and bypass system being tested for two Columbia River dams. Because of the concern for the negative impacts of screen systems...

Survival of Atlantic Salmon Smolts Bypassed Through Ice-Log Sluices Determined by the HI-Z Turb'N Tag
The HI-Z Turb'N Tag was used to assess injury and mortality incurred by Atlantic Salmon (Salmo salar) smolts bypassed through ice-log sluiceways at two stations. Both sluiceways were similar...

The Influence of Protective Material on Local Scour Dimensions
Protective materials installed around the base of a bridge pier can reduce or prevent local scour. The performance of four materials: grout mats, grout bags, footings, and riprap, are...

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...

Mechanics of Debris Flows
The paper deals with the mechanics aspects of the modelling of debris flows and will focus on steady, fully developed flows. After a brief review of the types of constitutive equations...

Kenetic-theory Approach to the Nevado Del Ruiz 1985 Debris Flow
The Nevado del Ruiz 1985 debris flow was the worst disaster of its kind in this century, killing 22,000 people. By making an idealization of the debris flow material and the flow regime,...

Repeatability and Oblique Flow Response Characteristics of Current Meters
Laboratory investigation into the precision and accuracy of various mechanical-current meters are presented. Horizontal-axis and vertical-axis meters that are used for the measurement...

An Application of Nonhomogeneous Poisson Process in Sediment Infiltration Into Gravel Bed
The compound homogenous Poisson process (CNHPP) model (Shen & Todorovic, 1971 ) is found applicable in sediment infiltration into gravel bed due to the unsteady and nonuniform...

Riprap Coverage Around Bridge Piers
Experiments were conducted to examine the effect of riprap size and coverage on reducing local scour at bridge piers. Pier diameter, bed material size, riprap size and diameter were varied...

 

 

 

 

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