Study On The Static And Dynamic Behavior Of Cable-Stayed Bridges With CFRP Cables

In recent years,with the development of greater span bridge,the problem of corrosion for traditional steel cable,the bearing efficiency for cable,and the structure weight has been become significantly,and the material which used for the cable-stayed bridge also set a higher request.Carbon Fiber Reinforced Polymer (CFRP) which has good performances of light weight,high strength,corrosion resistance and fatigue resistance has caught the attention and interest of the civil engineering realm.When material of CFRP used in the super long span cable-stayed bridges,there will be some advantages.On one side,the performance of high strength can be made full use.On the other side,the weight of super bridge will be lightened; the spanning ability and the carrying efficiency will be heightened.Thereby,the technology advantage and economy advantage of cable-stayed bridges with CFRP cables when constructing bridges over straits and seas.Recently,the related research and practical project are not very much,and the research productions are few yet.In china,the research on this field just stared.The work focuses on cable-stayed bridge using CFRP cables and some basic research are made,such as the mechanical properties of cable-stayed bridges with CFRP cables, the static load test of the experimental bridge,and the anchorage device for CFRP cables.The main content of the dissertation is briefly summarized as follows.1.The analysis of static load test and bonding anchors for experimental bridge with CFRP cablesThe actual working performance of the first cable-stayed bridge with CFRP cables in China during the service stage is inspected.The major contents and methods of static load test for cable-stayed bridge with CFRP cables are presented in detail. With the calculation of finite element model concerned,the stress and deflection behavior of the bridge structure measured in the test are compared and analyzed. Bonding anchors,which used in the first CFRP cable-stayed bridge and obtained the national patent,was analyzed by the finite element method.The radial stress of CFRP tendons are selected as major research parameters and influencing factors are also analyzed.At last,corresponding optimization schemes were given.2.Nonlinear static analysis of cable-stayed bridges with CFRP cablesThe theory and methods of all non-linear factors are introduced.Based on the discussion of the traditional mechanical model of cable-stayed bridge,the improved methods are made.The cable-stayed bridge with CFRP cables whose main span reaches 1000 meters-class and another one with steel cables are designed deploringly and the method of cable force optimization are also discussed.The mechanical properties of two cable-stayed bridges on dead load state are compared,and the influences of geometry nonlinear on dead load state are analyzed quantitatively.3.Nonlinear dynamic characteristics analysis of cable-stayed bridges with CFRP cablesThe finite element methods of dynamic characteristics analysis are introduced. The natural dynamic behaviors of cable-stayed bridge with CFRP cables whose main span reaches 1000 meters-class and another one with steel cables are analyzed contrastively.The influences of design parameters,such as structural system,the numbers of auxiliary piers,on dynamic characteristics of the cable-stayed bridge with CFRP cables are investigated.