Streambed instabilities around a bridge pier in a dredged channel

We conducted flume experiments to study the morphological behaviour around a circular pier located downstream of a mining pit. Severe transverse erosion at the pier base as well as lowering of channel bed upstream of the pier was observed because of channel dredging. Streambed instability was analysed based on two non-dimensional parameters, namely, pier exposure factor and normalized upstream incision depth. The maximum values of both these parameters were observed when the mining pit was dredged closest to the pier. We also observed growth in streambed instability with an increase in flow Reynolds number.