Scour depth at bridge abutments protected with a guide wall

An experimental study of scour development at abutments protected with a guide wall was carried out. Five types of guide walls were installed at a bridge constriction in a movable bed model and their efficiency for scour reduction at the bridge section was studied. Experiments were conducted at the threshold of bed material motion. Uniform bed material was used and tests were conducted at different conveyed discharges. Experiments showed that the short wing wall had the minimum and the long elliptic wall had the maximum efficiency in scour reduction. These guide walls reduced the scour depth at bridge section by 45% and 60% compared with a vertical unprotected abutment, respectively. The location of the maximum scour depth along the guide walls depended on their shape. Based on experimental results an empirical method was developed to calculate the scour depth at the bridge section. The depth of the scour hole at the guide walls nose is also studied.