Instrumentation for Measuring Scour at Bridge Piers and Abutments

This Digest summarizes the findings from the Phase I final report under NCHRP Project 21-3, which was conducted by Resource Consultants, Inc. NCHRP Project 21-3 was initiated in 1989 to develop, test, and evaluate instrumentation that would be technically and economically feasible for use in monitoring and measuring maximum scour depth at bridge piers and abutments. The research is being conducted in three phases. Phase I ( FY '90), which identified and evaluated instruments, included some small-scale laboratory testing. Testing was done in indoor and outdoor flumes at the Hydraulics Laboratory at Colorado State University. Currently underway, Phase II (FY '92) will midify, improve, and field test the most promising techniques identified in Phase I. It is scheduled for completion in March 1994. Phase III will extend development and deployment of devices for remote scour monitoring. The following categories of devices were identified during Phase I as capable of measuring and monitoring the maximum depth of scour at bridge piers and abutments: (a) sounding rods, (b) sonar, (c) buried/ driven rods, and (d) other buried devices.