Research on Load Bearing Performance of Pile Foundation for Superstructure Reconstruction of Bridge in Service

It is an important content of scientific evaluation of rationality, safety and economy of the bridge reconstruction plan to carry out the research on load-carrying properties of pile foundation for superstructure reconstruction of bridge in service. In order to understand the variation of load-bearing performance of pile foundation in the process of superstructure reconstruction of serving Bridges, based on the superstructure reconstruction project of Taiping Bridge and FEM software ABAQUS, the load-bearing performance of old piles, the difference in load bearing characteristics between old and new piles, and the load bearing performance under different pile lengths and diameters of new piles were studied respectively, providing references for the quality control in the process of superstructure reconstruction of serving Bridges. The results show that the vertical load bearing performance of the old pile foundation increases because the soil around the pile foundation is gradually consolidated. Vertical load-displacement change law of old and new piles are consistent, and the vertical differential settlement of pile top is small, which verifies the rationality of the new pile foundation design. When the length of new pile foundation grows by 9.1%, the settlement of pile top diminution by 1.14%. When the length of new pile decreased by 9.1%, the settlement of pile top grows by 1.5%. When the diameter of new pile foundation grows by 0.3m, the growth of pile carrying capacity is not enough to offset the influence of pile weight, and the vertical settlement of pile top increases. The differential settlement of old and new piles can be better controlled by increasing the pile length reasonably when designing the carrying capacity of super-long piles in superstructure reconstruction projects.