A field erodibility testing device for scour evaluation of bridges

Evaluation of scour in cohesive soil requires a good understanding of hydraulic erosion power from stream flow and the erosion resistance of the soil. In order to develop more reliable scour evaluation methods, the US Federal Highway Administration is investigating a few approaches for evaluating erosion resistance of cohesive soil. The In-situ Scour Testing Device (ISTD) produces a horizontal flow to simulate the flood conditions in an open channel and test the soil for erodibility. The erosion head assembly is compact in size and fits into the steel casing commonly used with hollow stem augers in a routine geotechnical subsurface exploration. The ISTD can be deployed to any depth that pier scour may reach to test the local material for erosion resistance. This device is calibrated using lab erosion testing devices and has been tested in the field.