Applicability Of New Type Assembled Piers For Mountain Railway In Complex Environment

With the development of Western China,the railway bridge project is extending to the West.Because the western region is in the complex environment of mountainous landform,the construction of the bridge has brought great difficulty.In order to overcome the above difficulties,the research and development of bridge structure with simple construction and high structural safety is the fundamental to solve the problem.The prefabricated bridge pier is easy to construct,requires little environment space,and has high efficiency.It has been paid great attention by the builders,which is helpful to solve the above problems.Therefore,it is of great practical significance to develop the fabricated pier structure with superior performance and study its seismic performance.Three kinds of new-type assembled piers are designed and optimized to be used in the railway bridge engineering in the mountainous area under the complex environment,and the performance of the new-type assembled piers is analyzed by comparing with the integral reinforced concrete piers,and the seismic performance of the new-type assembled piers is studied under the background of high intensity earthquake area.The main research contents are as follows:(1)I will read a large number of domestic and foreign literature and books,summarize the problems and difficulties existing in the construction of piers in mountainous areas under complex environment,including design difficulties,construction difficulties,durability problems,seismic problems,etc.,refer to the current national specifications and research design and optimize the new fabricated pier structure,including reinforced concrete pier(RC pier)and new fabricated Pier(CFST-F pier,CFST-Y pier,CFST-G pier),the strength,stiffness and stability of which are compared and analyzed,and the flange connection mode is designed and optimized,and the reliability of the connection is explored;(2)The single pier fiber model of RC pier and new assembled Pier(CFST-F pier,CFST-Y pier,CFST-G pier)is established by using OPENSEES finite element software.The seismic performance of the new assembled pier is discussed by simulating the low cycle reciprocating test,including the hysteretic performance,energy consumption capacity and ductility;(3)The dynamic time history analysis method is used to analyze the seismic response of the whole bridge of simple supported beam bridge with the new type of assembled pier.