SCOUR CONDITION ASSESSMENT
Bridge Scour Assessment Services
The bridge scour examination process normally involves a review of historical engineering operations and maintenance (O&M) information about the bridge, followed by a visual inspection. Information is recorded about the type of rock or sediment carried by the river, and the angle at which the river flows toward and away from the bridge. The area under the bridge is also inspected for holes and other evidence of scour along the channel, abutment and piers. Bridge scour is the removal of sediment such as sand and rocks from around bridge abutments or piers. Scour, caused by swiftly moving water, can scoop out scour holes, compromising the integrity of a structure.
Bridge Scour Countermeasure Design Services
In the United States, bridge scour is one of the three main causes of bridge failure. It has been estimated that 60% of all bridge failures result from scour and other hydraulic-related causes. Scour Condition Assessment is performed using the HEC-RAS hydraulic model to establish peak stages and velocities through the bridge opening, around piers, and along abutments. Countermeasures and prevention is performed applying the Hydraulic Engineering Circular No. 23 Manual (HEC-23) which contains general design guidelines as scour countermeasures that are applicable to piers and abutments. WRMA engineers have performed numerous bridge hydraulic scour condition assessments throughout the United States.