Analysis Of Seismic Response Of Large-Span Concrete-Fiiled Steel Tubular Arch Bridge

Attribute to the large transverse stiffness, better dynamic performance, elegancy of sculpting, convenience of construction and maintaining ,etc , the concrete-filled steel tubular(CFST) arch bridge has been abroad applied to the practices of civil engineering .The CFST arch bridge has been played more and more important role in people's production and living. And the theory of designing and the criterion of construction to apply them has been developing continuously. There are still many problems need to be researched when making full use of the performance of the CFST arch bridge.This paper has been researched the response issues of the concrete-filled steel tubular(CFST) arch bridge of the nielsen system in the seism .At the same time ,based on the incline or parallel of the arch rib of the arch bridge of the nielsen system, the superiority of the incline or parallel of the arch rib has been discussed. It's obvious that the transverse stiffness of the nielsen arch bridge with the arch rib inclined is lager than the parallel arch rib on the first system frequency. It's almost double larger on main frequency , therefore ,the displacement component of the arch bridge of the nielsen system with inclined rib is smaller. Furthermore, the time-history analysis and traveling seismic wave analysis give us best evidence that the arch bridge of the nielsen system with inclined rib has the advantages of large-stiffness and better aseismic performance. Generally, the paper has completed the work as follows.(1) Firstly, the methods of the response analysis of the seism has been discussed, which are commonly used in the engineering.(2) Secondly, based on the designing blueprint of the arch bridge, the finite element arch bridge of the nielsen system in ANSYS has been modeled .And the problem of the soil-structure interaction in the model has been simply simulated.(3) The paper has been analyze the effect to system frequency with the rib inclined or parallel ,it's obvious that the transverse stiffness of the arch bridge of the nielsen system with inclined rib is superior to the nielsen arch bridge with parallel rib.(4) At the same time, from the methods of response spectrum and time-history, compared the effect to the every response of the nielsen system of the arch bridge with inclined arch rib and parallel arch rib .It's very important to the nielsen system of the arch bridge with inclined rib.(5) In this paper, the traveling seismic wave analysis has been completed to the arch bridge with the two kinds of rib, it's very meaningful to realize the response of the arch bridge of the nielsen system under non-uniform excitation.