Studies On Push-over Method Of Bridge Structure

In recent years. Push-over analytical method is regarded as a new evaluation method for seismic resistance capacity of structure in some advanced countries. For example, in USA , Japan and so on. Push-over analysis can get more information than static elastic analysis and it is easy to operate. The basic theories, steps of analysis and the recent achievements about this method are discussed, and the method is applied to evaluate seismic resistance capacity of bridges structure in this paper. The capacity curves obtained by Push-over analysis and inelastic dynamic history analysis method are compared. The results show that Push-over method can replace inelastic dynamic history analysis method to analyze bridge structure under some conditions.The inelastic response demand spectrum of four site condition is gotten by employed Vidic's strength reduction factors method based on response spectrum of Chinese Code for highway engineering seismic resistance design (JTJ 004-89). The inelastic response demand spectrum can be employed to Calculate real bridges structural seismic resistance capacity.Target displacement is determined by capacity spectrum method. The capacity curves obtained by Push-over analysis method and inelastic dynamic history analysis method are compared. And the results of Push-over analysis method is nearby the same to inelastic dynamic history method analysis result. So Push-over method can be applied to evaluate bridge structure seismic resistance capacity and damage degree.The influence of P-A effect of bridges is discussed in detail. The P-A effect is related with bridges structural inhere characteristic by calculating five real bridges. And the P-â–³ effect must be considered in the slightness pier with heavy loads on top.