The Analysis Of Seismic Response Of Continuous Rigid Frame Bridges With High Piers And Long Span In Deep Reservoir

In recent years, continuous rigid frame bridges with long span and high piers are gradually applied in deep reservoir areas. However, the earthquake disaster is very frequent in China and the research on their antiseismic behaviour is deficient. So it is important to make an analysis for the seismic response of continuous rigid frame bridges with long span and high piers.In this paper, a continuous rigid frame bridge with long span and high piers is taken as the background, considering the influence of the pile-soil interaction and water dynamic effect, and a finite element model of the bridge is established by using the FEM program, ANSYS. Then the seismic response analysis of continuous rigid frame bridge is carried out using linear and nonlinear seismic response analysis method respectively in the paper.Firstly, a comparative research on the natural vibration characteristics and linear seismic response of continuous rigid frame bridges with long span and high piers in different depth of water is carried out, and the effect of the depth of water on the linear elastic seismic response of the structure is studied. Secondly, on the basis of this continuous rigid frame bridges with long span and high piers, considering different structural parameters and design parameters, corresponding calculation models of four-spans continuous rigid frame bridges are established in order to find out the influence of each parameter on the seismic behavior of the structure, which include the depth of water, the tie beam's quantity and position. Finally, the elasto-plastic seismic response analysis is conducted by using a model of plastic hinge element. Considering two conditions respectively, when the reservoir areas are waterless or water-filled, the elasto-plastic seismic response analysis and evaluation is conducted including the longitudinal with 2/3 vertical direction and transverse with 2/3 vertical direction, the purpose is to discuss the impact of the depth of water on the elasto-plastic seismic response of the structure. The results indicate that the structure's seismic applicability will be worse if the tie beam is set. The high natural vibration frequency of the structure will lower if considering the influence of water, the change of the depth of water has a significant impact on the seismic response of the structure; hydrodynamic pressure is disadvantageous to the seismic response of this kind of bridge. Therefore, the influence of the water can not be neglected in the analysis of the seismic response of continuous rigid frame bridges with long span and high piers.The results of study in this paper can give reference to the earthquake resistant study of the same kind of bridge.