Simulation analysis of prestressed concrete pipe pile applied to soft subgrade in seashore expressway

As a new technique of soft subgrade treatment, prestressed concrete pipe pile with geogrid has been used widely in road reconstruction and widening. The subgrade settlement, prestressed concrete pipe pile moment and tensile force of geogrid were analyzed using Plaxis from construction period to operation period. The results show that prestressed concrete pipe pile and geogrid-reinforced cushion can effectively decrease the differential settlement and total settlement of subgrade. The maximum amount of settlement is located in the new and old embankment lap position. Application of prestressed pipe pile makes the differential settlement significantly decrease, and geogrid adjusts the differential settlement by tensioning-pulling. The analysis of operation stability of subgrade shows that the subgrade is stable. Pile-Net structure can be used in highway reconstructed project. It could be further applied to relevant projects.