Seismic Response Analysis Of Continous Beam Bridge With Large Spans

In recent decades, earthquake disaster frequently occurred all over the world. And bridges are lifeline engineering, once destroyed, it will bring great damage to the lives and properties of people. Because PC continuous beam bridge is one of the most extensive bridges, it is necessary to make an in-depth study and analysis to the seismic performance of these bridges, which is an important factor for safety.Taking account of the present status of seismic response on large span bridge structures, a new seismic power spectrum density model is proposed to match the applicable codes of seismic design of road engineering. the model can be operated conveniently as substitute of the traditional response spectrum method.In this thesis, taking HuLiXi continuous beam bridge as an example, based on the basic theory of the seismic response analysis which was described, three methods including spectrum response analysis,time-history analysis and power spectrum density theory analysis of earthquake are applied to this PC continuous beam bridge. The main content in this thesis includes:(1)Research into the combinations of the seismic response and the establishment of the mechanics model;(2)Establish 3-dimensional finite element models and calculate the self-vibration characteristic of the bridge;(3)The engineering example is analyzed and the spectrum response analysis and time-history analysis are adapted and the analysis results are compared(4)The new seismic power spectrum density model is adapted to the engineering example and the analysis result is compared with the results of the spectrum response analysis and time-history analysis.The main conclusions from above include:(1)In the earthquake ground motion, the seismic internal force of the abutment pier of the continous beam bridge is larger than the other pier's(2)When the earthquake ground motion is inputted in X and Y direction , the displacement of the X direction and Y direction of the continous beam bridge is larger ,the Z direction's displacement is fewer. (3)Based on the large amount research of predecessors, a new seismic power spectrum density model is proposed to match the applicable codes of seismic design of road engineering.(4)Then the engineering example is analyzed, three seismic response analysis methods are adapted, accurate finite element model is established, and numerical analysis is performed based on stochastic seismic power spectrum density model which are proposed in this paper.The analysis result proofed the rationality and feasibility of the theories proposed in this paper. The model can be operated conveniently as substitute of the traditional response spectrum method.