Optimum safe design of bridge abutments to control and decrease the scouring

Abstract

The phenomena of scouring around bridge abutment is  the main reason  of bridge failure, so it must be investigated experimentally by using physical model of bridge abutment and using countermeasures that make on decreasing or controlling the scouring around bridge abutment in laboratory channel with width 1 m and applied three velocities (0.1, 0.08 and 0.07) m/sec. In this study it was studied  the effect of pile shape and  pile distance from the abutment on decreasing the scour around  vertical-wall abutment and the effect of using collar on bridge abutment. It was studied: effect of distance of two circular pile in upstream of the abutment to decrease the scour, the distance that was taken (0.88B=20 and 1.30B=30 cm) where B represent the abutment width from abutment, It was concluded for the first case that the circular pile with distance 0.87B can reduce the scour about 50% than the distance of 1.3B, oblong pile can reduce the scour with high percentage and the collar on bed can reduce the scour about 98%.