CONTROL OF LOCAL SCOUR DEPTH AROUND BTIDGE PIER USING DOWN STREM BED SILL

Abstract

This study is based on laboratory experiments for computing depth of local scour around bridge pier when a downstream bed sill using as a countermeasure.A circular section pier model has been used with clear water flow condition. However, sand was used as a bed sill.

Three different size of pier diameter are investigated with four different water depths and four different flow velocities. It is found that the diameter of the pier is an important parameter influencing the scouring process around pier.Bed sills at different distance from pier downstream and with different width and thickness, were used as a countermeasure to reduce the local scour depth. The level of sill crest was the same elevation of bed material. As a results of a study, the analysis of experimental data shows that the usage of sill as a countermeasure structure has a beneficial reduction of scour around pier around 25% for flow intensity 0.95.