Analysis Of Seismic Response For Long-span Cable-stayed Arch Bridge

The long-span cable-stayed concrete filled steel-tubular arch bridge is a kind of new bridge structure form, which combines the cable-stayed bridge and the arch bridge harmoniously. It exhibits the respective merits of the cable-stayed bridge and the arch bridge, and makes two kinds of advantages of bridge type get to add mutually. It is also a breakthrough in the aesthetics of bridge that the cables fasten on the arch rib make the bridge more beautiful. But as same as other type long-span bridges, The problem of anti-seismic is unavoidable to the cable-stayed arch bridge. And there is also a little of study reference about anti-seismic of the cable-stayed arch bridge. In this dissertation, based on the forth bridge of XIANGTAN, certain problem relating to seismic response behavior of the cable-stayed arch bridge are studied.They included:1. The recent studies on asynchronous seismic model are summarized. And based on Harichandran&Vanmarche one dimension coherence model and the geological conditions, the asynchronous seismic model is developed by one dimension stochastic vector process, and the spatial relation is included in the model.2. With cable-stayed arch bridge which is the forth bridge of XIANGTAN for engineering background, make use of large and general finite element soft ANSYS to analysis the seismic response behavior under the spatial asynchronous seismic model. And on the basis of the linear finite element model, the effect of different factor such as the sloping angle of arch rib , the form of the hangers, the arrangement form of the lateral brace, ratio of the width to the span, the stiffness of the arch rib, the cables position on the arch rib etc is discussed.3. The geometric nonlinear seismic response behavior of the cable-stayed arch bridge is analysis. Based on the elastic-plastic stiffness matrix of concrete filled steel-tubular (CSFT), the material nonlinear seismic response behavior of the cable-stayed arch bridge is also studied. The different anti- seismic capability between the cable-stayed arch bridge and the same span tie-through arch bridge is studied. And based on the concept of the maximum response plastic rate, the estimate of material nonlinear seismic response behavior is developed.4. The linear stochastic seismic response analysis of the cable-stayed arch bridge and the same span tie-through arch bridge are studied and analysed.