Analysis Of Seismic Performance For High Speed Railway Piers With High-Strength Steels

With the vigorous development of high-speed rail construction,many high-speed railway bridges need to be built in high-intensity seismic zones such as Yunnan,Guizhou,Sichuan,and Tibet.The use of high-strength steel can not only reduce the amount of steel bars,save costs and protect the environment,but also solve the problem of concrete pouring vibration caused by excessive steel reinforcement in concrete construction.Therefore,high-strength steel bar has a good application prospect in high-intensity area high-speed railway bridges.However,according to the general rule,the increase of longitudinal reinforcement strength will lead to the reduction of ductility and deformation capacity of components.The investigation of the quasi-statics test of the railway RC bridge piers with HRB500 high-strength reinforcements shows that the displacement ductility coefficient of most piers can not meet the requirement 4.8 of Code for Seismic Design of Railway Engineering.Therefore,it is of practical significance to study the application of HRB500 high-strength steel bar on high-speed railway RC piers.This paper takes high-speed railway piers with high-strength steel bars as the research object.The main contents are as follows:(1)Based on a large number of domestic and foreign literatures,this paper analyzed and summarized the research status of seismic performance of reinforced concrete bridge piers and the research status of seismic performance of pier columns with high strength steel bars at home and abroad.(2)Sensitivity analysis was carried out on the influence factors of deformation capacity and bearing capacity of HRB500 reinforced high-speed railway RC pier under horizontal monotonic load.The main influence factors were obtained by orthogonal test method,and the influences of the main factors on the bearing capacity and displacement ductility coefficient of HRB500 high-speed railway RC bridge.And the reasonable reinforcement range of piers to meet the displacement ductility ability in accordance with the requirements of the standard under horizontal monotonic load was summarized.(3)The sensitivity analysis of the influence factors of the HRB500 high-speed rail RC bridge piers under horizontal cyclic loading was carried out by orthogonal test design.The most important influence factors were selected,and the influences factors of the main factors on the bearing capacity,ductility characteristics,energy dissipation capacity and stiffness characteristics of the pier were analyzed.Then,the reasonable reinforcement range of the displacement ductility ability according to the requirements of the standard under horizontal cyclic loading was given.(4)IDA method was used to study the displacement ductility of RC piers of high-speed railway with HRB500 steel bars under actual ground motion.And summed up the reasonable reinforcement range of the displacement ductility ability that met the requirements of the specification under the actual ground motion.