An experimental study of the effect of simple spur dyke on the local scour around the bridge abutment

The occurrence of scouring is one of the most important threats to the stability of the bridges which built on the rivers. In order to prevent possible destruction and irreparable damages, it is necessary to control scour by carefully examining the scouring process and applying appropriate methods. In this research, by constructing a laboratory model, the effect of using a simple spur dyke on the reducing of the scour around the bridge abutment which located on the erodible river bed was investigated. For this purpose, a spur dyke structure with certain dimensions and specified distance from the bridge abutment (according to the flow characteristics of river geometry) was used and the effect of each parameter on the scouring of the abutment was examined. Also, based on statistical analysis using the SPSS software a regression relationship achieved for estimating the scour depth around the abutment. The results of this study indicate that the protective spur dike reduced the scour depth around the bridge abutment nearly 94%. Also, the efficiency of the spur dike was directly related to its length and inversely related to its distance from the abutment.