Abstract: Scour is the process whereby rushing water removes streambed silt. Aggradation is the gradual build-up of the stream bed in reach as a result of silt deposition. The failure caused by scouring ranks second in terms of overall bridge failures, behind floods. There hasn't been any research done to far on the maximum scour depth, particularly for piers with rectangular and triangular shapes. In order to do this, a number of tests were carried out in a recirculating flume at the Shantilal Shah Government Engineering College in Bhavnagar, Gujarat, which is 6.0 meters long, 0.30 meters wide, and 1.0 meters deep. The sediment's d50 size is 1.3mm. Four different pier forms were used in a total of 16 runs, with the triangular shape showing the greatest scour depth and measuring 48.7% greater than the circular pier.

| DOI: 10.17148/IARJSET.2023.10548