Three Dimensional Numerical Simulation And Analysis On Seismic Performance Of Compound Reinforced Pile

Because of high vertical bearing capacity and convenience of the prestressed concrete pipe pile(PHC pipe pile),it’s commonly used in pile foundation engineering of high-rise buildings and bridges.But it has the characteristics of brittle failure,earthquake disaster investigation abroad in PHC pipe pile is more serious,with the domestic PHC pipe pile foundation accident,various codes restricted PHC pipe pile,which limits the application and popularization of PHC pipe pile.In order to improve the seismic performance of PHC pipe pile,some scholars add non-prestressed to PHC pipe pile to improve its seismic energy dissipation performance.However,the research on mechanical properties of pile body and the influence factors of the seismic performance of the PRC pile(called pipe pile in the paper)is not thorough.In this paper,the horizontal bearing capacity and seismic performance of composite pile foundation are systematically studied by using ABAQUS finite element software,on the basis of field tests.Firstly,the static finite element model of single pile which considering pile-soil interaction on the basis of the field test is built,low cyclic loading are put on the top of pile to simulate the quasi static loading test,comparing with the test results to verify the reliability of the model.On the basement,this article apply Principles of quantitative comparative analysis to analyze influence factors on seismic performance of composite reinforced piles by changing the model parameters,which including non prestressed reinforcement,prestressed reinforcement,stirrup ratio,core filling,pile diameter and vertical load.It is found that there is an optimum ratio of reinforcement in non-prestressed bars and prestressed bars,so that the ductility of pipe pile is the best,the effect of increasing stirrup reinforcement ratio on the seismic performance of pipe pile is smaller than other factors,reinforced concrete core filling and increasing pile diameter can improve the ductility of pipe pile under some conditions,the vertical load will reduce the ductility of pipe pile,and the influence of vertical load should be considered in the actual design.Then,this article compares and analyzes the dynamic response of composite reinforced piles under different strength and different kinds of seismic waves by establishing dynamic model of finite element infinite element coupling on single pile.It is found that,although the seismic response of piles under different seismic waves is different,the maximum seismic response of pile body occurs at the boundary of different soil layers.The shear failure occurs in soil at this depth,so the pile bears greater seismic shear force.In order to improve the safety of the pile body,the appropriate reinforcement measures for the pile can be taken at this position.Under the action of rare earthquake,the peak moment of pile body does not exceed the flexural capacity,and it can be find out that the seismic performance of PRC pile is excellent,and it is partial to safety.