Study on local scouring at suramadu bridge piers for structural integrity monitoring

Local scour at bridge piers needs to be monitored regularly when the bridge is in-service since it may affect the integrity of the bridge structure and occasionally it can lead to a catastrophe. Scour at bridge piers varies with water depth, flow velocity and duration, pier geometry, and other factors. This paper discusses results of local scour study at piers of Suramadu Bridge, which is at present the longest bridge in Indonesia, for monitoring of its integrity. Field investigations were carried out to obtain sea water current speed and direction, the sea bottom profile, and seabed soil size distribution. Areas at the vicinity of the bridge piers where scouring and sedimentation took place were obtained by comparing results of this study to those of similar study reported earlier. In addition to field investigations, numerical investigation was also conducted in this study to estimate local scour depths occurred at piers of the bridge. Scour depths obtained from the measurements in the field and those numerically computed were compared. Effect of estimated scouring on the bearing capacity of the bridge pier foundation was then investigated. Results of the study showed that the integrity of Suramadu bridge structure was not affected under the estimated scour depth; however, monitoring of the bridge structure requires to be conducted regularly so that its structural integrity can be assured.