Author(s): Gaurav Misuriya; Ti Eldho

Linked Author(s): Gaurav Misuriya

Keywords: Local scour; Bridge pier; Unsteady flow

Abstract: From ancient time, bridge played an important role in the development of a civilization. Being an important part of bridge design, the bridge pier needs special attention. In the design of a bridge pier, local scour is one of the prime factors that needs to be estimated accurately. Local scour can be affected by flow properties, fluid properties, and pier shape and dimensions. Numerous research work has been performed in the past to study the effects of different parameters and to accurately estimate the local scouring around the bridge piers. However, most of these studies are concentrated on local scour around a circular bridge pier over sand bed in steady flow conditions. Unsteady flow in the form of a flow hydrograph, even though being closer to the real field condition got very less attention. This study investigated the effect of pier shape on the local scour around the bridge pier over gravel bed under unsteady flow conditions. The pier shapes considered in this study were cylindrical and square. The flow was varied with time to produce a triangular shaped hydrograph. Time variation of the flow in the flume was controlled by a Programmable logic controller (PLC). Uniform gravel with a median diameter (d50) of 4.9 mm was placed in the flume as bed material. The results showed that the maximum scour depth around square pier was 1.3 times than that was around the circular pier. However, shape of the pier does not affect the extent of scour hole.

DOI: https://doi.org/10.3850/IAHR-39WC252171192022321

Year: 2022