Probing the Port of Los Angeles
Geotechnical investigations can uncover nasty surprises. When conducted after the preliminary design, the results can force significant and costly changes or�even worse�lengthy delays....

Recycling on the Mississippi
Changes in the Mississippi River's water depth and alignment are forcing the retirement of the 105-year-old Hannibal, Mo. swing bridge. Although the bridge's...

Rocking Behavior and Retrofit of Tall Bridge Piers
In the aftermath of the damage to the San Francisco Oakland Bay bridge, due to the 1989 earthquake, a comprehensive study of the seismic behavior of the bridge was undertaken. This paper...

Reliability of Highway Bridge Piers
Structural safety of reinforced concrete bridge piers supporting highway traffic is studied. Reliability indices for flexure, shear, and combined flexure and axial load limit states at...

Equations to Predict Critical Submergence at Horizontal Hydraulic Intakes
The formation of free surface vortices at hydraulic intakes can disrupt operation and damage machinery. It is also a serious safety concern. Theoretical investigations and laboratory tests...

The Separated Flow Around a Circular Bridge Pier
The unsteady separated flows around a flat plate/cylinder junction and a scour hole/cylinder junction were investigated experimentally. The flow in the plane of symmetry was presented....

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...

The Influence of Exposed Footings on Pier Scour Depths
Data compiled from past test efforts are combined in this article with the results of two new flume test studies. The combined material, presented graphically, suggests a method for adjusting...

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...

Local Scour at Skewed Bridge Piers
Presented herein are experimental data showing the influence of pier skewness, also referred to as angle of attack, on depth of local scour at rectangular and oblong bridge piers. The...

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...

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...

Cable-tied Concrete Block Erosion Protection
An articulated concrete erosion protection system is investigated as a possible revetment for bridge piers to be used in place of the traditional rip-rap revetment. The system consists...

A Method of Managing Floating Debris
The device described offers a promising approach to a new method of managing floating debris. It modifies the surface flow of water from a submerged location. The modified flow reduces...

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...

Emergent Techniques in Scour Monitoring Devices
This paper presents a brief status report of a research and development project funded by the National Cooperative Highway Research Program (NCHRP) to develop and test scour monitoring...

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...

Model Study of Local Scour Downstream Bridge Piers
A deep scour hole downstream of a large circular pier has been developed at Imbaba bridge, which is considered one of the major bridges across the Nile River in Cairo, Egypt. At that location...

 

 

 

 

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