Results of a Reconnaissance Bridge-Scour Study at Selected Sites in Oregon UsingSurface-Geophysical Methods, 1989

摘要

Three geophysical methods--ground-penetrating radar, high-frequency continuosseismic reflector (tuned transducer), and a color fathometer--were used to examine 14 bridge sites in Oregon, to determine the usefulness of each method in locating and determining depth of infilled scour holes around bridge piers in Oregon streams. Each geophysical method was capable of detecting infilling around piers, but because of equipment limitations, not every method was effective at each site. The softer infilled material present at nearly all sites was probed by a metal rod to verify data collected by the geophysical equipment. Scour equations were marginally successful in predicting two existing scour holes that were identified as having been caused by a peak flow. Most study sites had local conditions, such as riprap, debris, or remnants of old coffer dams that invalidated the use of equations.