The Test Research And Finite Element Analysis On The Seismic Performance Of SC Pile Filled With Core Concrete

Centrifugal concrete filled steel tube pipe pile(SC pipe pile),a new type of composite materials,has a good application prospect combining the characteristics of steel tube and concrete,so it has a good seismic performance.In consideration of the operation environment of the pile in practical engineering and groundwater erosion,it is always taken steps to fill the SC pile with core concrete in order to change the stress of the pipe pile performance and improve the bearing capacity of pile.Study in the seismic behavior of SC pipe pile is rare in China,especially the research on the seismic performance of the SC pile filled with core concrete,which severely limits the popularization and application of SC pipe pile.Therefore,researching on its mechanical properties plays a positive role in promoting the market development in the field of precast piles.The seismic behavior indexes of SC pile,SC pile filled with core concrete,PHC pile and PHC pile filled with core concrete obtained by low-cycle loading experiments.The analysis and comparison of the failure mode and the seismic behavior indexes like skeleton curve,ductility,energy dissipation capacity and stiffness shows that the seismic performance of SC pipe pile is significantly better than PHC pipe pile,but core concrete in SC pipe pile will not improve the seismic performance significantly.On the basis of the experiment research,ABAQUS was used in finite element simulation of the seismic performance of the test specimens.The results of the simulation agree well with the experiment data.Using the validated finite element program,the influence of concrete wall thickness and material strength,steel pile wall thickness and material strength,core materials to the seismic performance of flexural members in SC pipe pile filled with core concrete was analyzed.Combining the experimental and finite element analysis results,trilinear theoretical model of skeleton curve of SC pipe pile was proposed.The simplified calculation method of parameters in this model was deduced through theory.The comparative analysis of the curves calculated through theory and obtained by experiments verifies that this model can perfectly reflects the real skeleton curve of members,which can provide reference for the design of the SC pile filled with core concrete.