The recent failure of bridge pier footings and foundations because of scour and erosive processes has resulted in the need to monitor the maximum scour depths. During the past 5 years, more than 30 types of device for measuring scour have been developed for field use.Many of these devices have not been fully tested either in laboratory or field situations. A laboratory testing program was conducted to evaluate the effectiveness and practicability of several scour-monitoring devices. A series of flume tests was performed to evaluate driven and falling rod model devices. Sonar measurement devices were tested in a sump and visual accumulation tube to analyze the affectsof transducer transmission angle, transducer mounting angle, transducer submergence depth, transducer mounting distance from the pier, and temperature on accuracy and reliability. It was determined that vertically supported falling rods and the scuba mouse were practicable devices when mounted in front of the pier. The sonar device has ahigh potential for field application, although it is sensitive to water temperature, mounting angle, and transducer placement location in front of the piers
Samenvatting