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...

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...

The Study of Riprap as Scour Protection for Bridge Abutments
The purpose of this paper is to provide design guidelines for riprap protection of spill-through and vertical-wall abutments situated in floodplains. With the benefit of laboratory experiments,...

Pier Scour Equations Used in China
This report describes the equations used in the People's Republic of China for estimating scour depth at bridge structures. The equations were worked out from model and field data at the...

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...

Supply of Large Woody Debris in a Stream Channel
The amount of large woody debris that potentially could be transported to bridge sites was assessed in the basin of the West Harpeth River in Tennessee in the fall of 1992. The assessment...

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...

Scour at Highway Structures in Tidal Waters
Scour analysis of bridges over tidal waterways uses the same scour equations as for the rivers. However, determining the hydraulic variables to use in the equations is complex. A major...

Bridge Hydraulic Design in Tidal Situations
The analysis of bridge hydraulics and scour potential in tidal waters, in comparison with inland rivers, requires consideration of various additional factors. This paper condenses a simplistic...

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...

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...

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...

Threats to Bridge Stability from Scour Related Failures of Drop Structures
Catastrophic failure of bridge foundations may occur when channel bed elevations are lowered unexpectedly. Bridges to be constructed in channels that are known to have bed degradation...

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 Design at Bridges?Factor of Safety Approach
The factor of safety method offers a physically based methodology for design of riprap that relates the applied shear stress on the channel boundary to the stability of the riprap layer....

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...

Predicting Critical Scour Stage at Bridges
After an initial level I screening process, most level II bridge scour studies result in recommendations for costly scour countermeasures. Typically, existing transportation budgets cannot...

 

 

 

 

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