The Influence Of Shear-span Ratio On The Seismic Response Of Round-ended Solid Piers In High Speed Rail

Abstract:As the lifeline project, high-speed rail bridges once damaged in the earthquake, will cause traffic disruptions and increase secondary disasters. According to the statistics of bridge failure forms on the earthquake, pier damage is the main cause of bridge failure or collapse. Thus, the seismic performance of the pier affects the entire seismic performance of the bridge structure, the research of the seismic response characteristics of bridge piers is essential. At present, experimental and theoretical studies on the seismic performance of the bridge pier mostly use highway bridge piers as the prototype. The research targeted on the round-ended piers of high speed rail is rare, relevant research data about shaking table test is extremely lacking. Therefore, there is an urgent need for a large number of experimental research and theoretical analysis on the high-speed rail pier. In this paper, we choose the commonly used solid round-ended pier in high speed rail as the prototype, focus on the seismic performance research through multi-dimensional seismic shaking table test; the main contents of the paper are described as follows:(1) According to the similarity theory, high-speed rail solid round-ended pier model is designed. Through the shaking table test under different peak gravity acceleration, the seismic behaviors including the dynamic properties, acceleration response, the damage process and the crack development process are demonstrated. Using finite element analysis software ABAQUS, the results of finite element analysis and experimental results are compared each other and it verifies the correctness of finite element analysis methods and test methods.(2) Using model piers as the research object, finite element solid models under different shear-span ratio are built and the elastic-plastic time history analysis is applied to compare the results of the analysis under horizontal ground motion with that under combined horizontal and vertical ground motion. Through comparison and analysis of the seismic response results, it clarifies the affecting law of shear-span ratio and vertical ground motion to the failure modes and seismic performance of high speed rail pier. (3) By inputting different combinations of bi-directional horizontal seismic loads, it analyzes the seismic response of small shear-span ratio pier and finds the combined effects of the earthquake on the small shear-span ratio pier.