Experimental and theoretical study of sediment scour around angled bridge piers

The present study investigated a square-shaped group pier with attack angles of 0°, 10°, 15°, 20°, and 30° and spacing of 2, 3, and 4 times the pier width and a single pier with the same attack angles in the same experimental conditions. Also, a semi-empirical equation was presented for predicting the maximum depth of scour for single pier and group pier, which had good agreement with experimental results. Results indicated that by considering the angle of the single square pier, the flow impact area on the pier was altered, and the maximum depth of scour was reduced due to deformation resulting from the attack angle of the pier. In the tests related to the group pier, the attack angle of 15° was known as the critical attack angle in this study, which agreed with the results of previous studies.