Seismic Response Analysis Of Prestressed Concrete Continuous Rigid Frame Railway Bridge With Tall Pier And Large Span

In recent years, with the development of bridge structure, the span becomes longer, the height of pier becomes higher and higher, and framework becomes more and more flexible, which presents many new problems in the studies on the aseismic design of long-span bridge. In seismic design and seismic assessment of bridges, it is necessary for us to understand dynamic responses of bridges under strong earthquakes, especially the responses of bridges with high piers or long span, dynamic characteristic of long-span bridges with long natural period is very complicated. To study the influences of duration of strong earthquakes on structures can help us comprehend the responses of structures and improve their seismic capacity.In this thesis, taking Qinghegou Bridge as the research object, based on the basic theory of the seismic response analysis, two methods including response spectrum and time-history analysis of earthquake are applied to a continuous rigid-framed bridge. The main content in this thesis includes:1. Establishing three calculation models of the bridge; considering the influence of the pile-soil interaction and different foundation; analyzing the dynamic characteristics of the three models respectively.2. The seismic response of the four models were analyzed by response spectrum and dynamic time-history analysis methods. By changing the speed of the earthquake wave, the traveling-wave effect were analyzed.3. Analyse the different types of seismic waves on the impact of time-history analysis, and pointed out the solution.4. The influences of the vertical seismic effect was discussed. The main conclusions from above include:(1) The pile-soil interaction and the deformation of the foundation reduce the natural frequency and increases the displacement response of the bridge.(2) Compared with the results of seismic response obtained by response spectrum, the results obtained by time-history analysis method increases or decreases, we should adopt the larger result when design. (3) The internal force and the displacement of the bridge increases or decreases with the difference of the speed of the earthquake wave, we should choice the corresponding speed of the earthquake wave according to the actual ground soil when design.It is expected to give some references for practical seismic design of similar bridges.