| The high-capped-Pile foundation has been widely used in bridge engineering inconsequence of its many advantages. Based on the pile foundation of railway bridge has highlevel vertical bearing capacity, the horizontal bearing capacity is relatively poor, and byadopting the combination of experimental research and numerical analysis method, theseismic performance of railway bridge piers and the stress distribution and change rule of pileshaft under the horizontal loading is systematically studied. The main research work is asfollows:（1）Based on consulting a large number of literature, earthquake damage characteristicsof bridge pile foundation and the current research status of bridge pile foundation seismic testare systematic summaried.（2） The theory and calculation method of linear and nonlinear analysis of single pileand group pile foundation is introduced under the action of horizontal loading.（3）A specific real bridge piers based on passenger dedicated line as the research object,the pile group foundation pier model with the ratio of1:8is set up in indoor. The force-displacement hysteretic curve and skeleton curve of the whole structure of pile soil-pile caps–pier is achieved by using the pseudo-static test under low reversed cyclic loading at the topof the pier. Through measuring and analysing the strain of the longitudinal reinforcement ofpile shaft, the pile body stress distribution and change rule of each row pile of group pilefoundation is achieved under the action of horizontal loading, and the destruction mechanismof elevated pile caps of railway bridges and foundation is analyzed.（4）On the basis of experimental study, the method of equivalent nonlinear springrecommended by Japan’s related specification simulate the elastic-plastic soil. The P-MMhinge is used to stimulated the elastic-plastic of pile shafts under the variable axial force, andthe M hinge is used to stimulated the elastic-plastic of pier. The elastic-plastic beam elementanalysis model is established, and the rationality of the analysis model is verified by modeltest.（5）The Pushover analysis is carried out on the experimental model, the skeleton curveof pile-soil-structure interaction is achieved, which is in good agreement with the test results. Based on static nonlinear analysis model of group pile foundation, the distribution and changerule of each pile in pile axial force, bending moment of pile head negative bending moment ofthe top elevated pile caps is studied under the action of horizontal loading. The pile bodystress is calculated under horizontal load. The calculation results show that the pile bodyposition of maximum consistent with experimental results. |
