Research on Seismic Performance of New Type Railway Ductile Structure Pier in Strong Earthquake Area

Research purposes:In order to ensure the safety and smoothness of train operation, the high speed railway bridge piers are often large in size and stiffness, which makes it difficult for the pier to form the plastic hinge at the bottom of the pier under the action of strong earthquake, and the seismic force of the pile foundation at the bottom of the pier is too large, which is easy to damage the pile foundation, and the pile foundation design is not economical. Therefore, it is urgent to carry out the research on the new ductile structural pier, so as to reduce the earthquake damage to the piers and pile foundation and improve the seismic performance of the round end pier on the premise of ensuring the operating stiffness. In this paper, two types of ductile structural pier design schemes were proposed. Xtract nonlinear analysis software was used to study the seismic performance of the pier base section and analyze the influence of different design parameters on the key seismic performance indexes of the pier. The developed ductile structural pier meets the operational rigidity requirements of railway bridges and can reduce the seismic force by 30% ~ 50% under strong earthquakes. Research conclusions:(1) The proposed design scheme of ductile structural pier of high - speed railway realizes that the stiffness and strength of ductile structural pier are the same as that of the original bridge pier under normal operation and small earthquake action, and the first yield moment is 0. 85 ~ 1. 05 times of the original bridge, so as to ensure the train running safety. The stiffness of the ductile structure pier decreases under the action of strong earthquake, the maximum seismic force at the bottom of the pier is 0. 5 ~ 0. 7 times that of the original pier, and the ductility ratio of the pier is 1. 4 ~ 1. 9 times that of the original bridge, which realizes the design goal of the ductile pier and protects the pile foundation.(2)The equivalent yield moment and ultimate moment of the new ductility pier are positively correlated with the area ratio of rebar after internal shrinkage.(3)With the increase of mortar strength, the initial yield moment and equivalent yield moment of pier section will gradually increase, but the ultimate bending moment of pier section is not affected by mortar strength.(4)The research result can provide a reference for the seismic design of railway pier in strong earthquake area. © 2023 Editorial Department of Journal of Railway Engineering Society. All rights reserved.