Impact of the backfilled soil on the lateral stability of plug-in steel cylinder under wave load

The application of plug-in steel cylinders in bridge-tunnel systems has a bright future in the development of cross-sea traffic. As for the wall of the man-made island, the lateral wave force is the main threat for the stability of the cylinder. This study analysed the influence of the properties of backfilled soil on the stability of cylinders using a numerical simulation method. The stability of cylinder filled with clay was also compared to that of a cylinder filled with sand. Results show that every 1 kN/m3 increment in the weight of sand and every 1° increment in the inner frictional angle of sand result in approximately 1300 and 180 kN increment in wave load, respectively. The variation in weight could increase the critical wave load only if the cohesion of the backfilled clay was larger than 40 kPa. In addition, it is reliable to replace the backfilled sand with clay.