Research On Seismic Behavior Of Pile Foundation Piers Considering The Interaction Between Pile And Soil

Gravity piers with rare-reinforced concrete are widely used in our country’s railwaybridges, so it’s significant to know its seismic behavior. Nowadays, most of the study ofseismic behavior on bridge piers are only focused on pier itself, without considering theinfluence of pier caused by the pile-soil interaction system. In view of seismic analysismethods of our country’s railway bridge gravity pier and problems in engineering applicationon interaction between pile and soil structure, based on piers of a railway passenger line,using reduced-scale model test combined with numerical simulation, this paper researches theseismic behavior of piers considering the interaction between pile and soil. The major work ofthis paper includes the following aspects:(1) The reasons of the damage on bridges are analyzed, the research status at home andabroad of the pile-soil-structure interaction system and quasi-static test is summarized in thispaper.(2) Through reduced-scale model with ratio of1:8quasi-static test in laboratory, thispaper obtains hysteresis curves, skeleton curves, energy dissipation capacity, strength andstiffness properties of pile foundation piers under low cyclic loading, and analyses the failuremechanism of low cap pile foundation.(3) Determining the bilinear model of soil pressure by referring norms of Japan, usingUCfyber program to calculate the moment-curvature relationship of the bridge pier crosssection, whole finite element analysis model is established considering material nonlinear ofsteel and concrete and foundation soil nonlinear.(4) The test model pier is analyzed using the method of Pushover analysis, skeletoncurve of horizontal force-displacement relationship of model pier is obtained, and thisskeleton curve is compared with skeleton curve obtained by the model test. Meanwhile, thefailure mechanism of pile foundation piers is analyzed by comparing the results of numericalanalysis with damage phenomenon of pier in the process of test.(5) Pushover method is used to analysis prototype pier with numerical simulation method,and capacity curve of prototype pier is obtained. Elastic-plastic demand spectrum curve ofprototype pier is obtained based on the equivalent damping ratio. Seismic behavior of pile foundation piers considering the interaction between pile and soil is evaluated by usingcapacity spectrum method. The results show that the prototype pier can resist earthquakeacceleration less than0.15g.