Experimental And Theoretical Research Study On Seismic Behavior Of Prestressed High Strength Concrete Pipe Pile

In recent decades,the technology of prestress and high-strength concrete developed rapidly.PHC pipe piles(in full strength prestressed concrete),typical of these precast concrete is increasingly widespread application.Compared with other foundation,prestressed high strength concrete pipe piles has many advantages,the vertical bearing capacity is stronger,the construction speed is faster,the scope is larger,the production process is easier,and the level of industrialization is higher.Since the 1970 s,PHC pipe piles give a very wide range of applications in China's port construction and water conservancy projects,roads and bridges.After the under construction residential building collapsed events in Shanghai Lotus,the problem of the pipe piles anti horizontal force gradually aroused extensive attention of the engineering sector.There are still many aspects of our deficiencies in research on seismic performance of pipe piles.The research of whether can further expand the pipe piles range of applications and deformability and stress state of the PHC pipe piles under earth quake has very important significance.This experiment design six prestressed high strength concrete pipe piles.Factors to consider are filled core,the incorporation of steel fibers and adding non-prestressed reinforcement.Based on the low cyclic loading experiments on the six PHC pipe pile.The seismic performance in terms of the damage characteristic,bearing capacity,ductility,hysteretic characteristic,rigidity degradation and energy dissipation of PHC pipe piles are compared and analyzed.The results show that filled core,the incorporation of steel fibers and adding a non-prestressed reinforcemen can improve the carrying capacity of pipe pile,the hysteretic performance of PHC pipe piles will be improved and the speed of rigidity degradation is slower.Therefore,improvement measures can improve the seismic performance of PHC pipe piles.The PHC pipe pile filled core and added steel fibers has higher deformation behavior,ductility and energy dissipation capacity.The the carrying capacity of PHC pipe pile adding non-prestressed reinforcement is improved a lot,the deformation capacity is also improved a lot.The stiffness degradation turns down and the energy dissipation capacity improves a lot;These three measures can improve the seismic performance of pipe pile.Compared with pile cored,configuring non-prestressed reinforcement improves the seismic performance a lot.Configuring non-prestressed reinforcement and pipe cored is the best measure to improve the seismic performance of PHC pipe pile.By studying the model,theory,index of cumulative damage and analyzing the cumulative damage of each PHC pipe piles,we can gei the conclusions that all three improvements can cut the cumulative damage back under the limit state of PHC pipe pile.Configuring non-prestressed reinforcement in the body of PHC pipe pile and adding steel fibers in the concrete is the best measure to cut dowm the cumulative damage.