Seismic Response Analysis Of Self-anchored Cable-stayed Suspension Bridges Based On The Improvement Pushover Method

With the improvement of people's aesthetic concept,many beautiful shaped bridges have been built in cities.However,such bridges often pose problems such as complex structures,unreasonable forces,and unclear mechanical properties under earthquakes in the pursuit of landscape requirements.The current IDA has a large amount of computation and low computational efficiency,while the traditional Pushover analysis method does not consider the issue of seismic history.This paper takes the cable-stayed cable bridge as the research object,uses the improved Pushover analysis method,and studies the improvement through the finite element software.The feasibility and applicability of the improved Pushover method in the seismic performance analysis of the self-anchored cable-stayed catenary composite bridge are studied,and a new idea for the seismic analysis of the bridge with complex structural system is provided.The main content of this article is as follows:(1)According to the research results of structural earthquake resistance methods by scholars at home and abroad,combined with the mechanical properties of the self-anchored cable-stayed-stayed cable combination structure,the problems existing in the current seismic analysis method are clarified.By summarizing the advantages and disadvantages of each seismic analysis method,the principle and implementation flow of the improved Pushover analysis method are studied,and the theoretical support for verifying the improved Pushover analysis method is provided for the applicability of complex self-anchored cable-stayed cablestayed composite bridges..(2)Based on the bridge project,establish SAP2000 finite element model,The problems involved in the modeling process such as structural dispersion,restoration force model establishment and seismic wave selection were discussed.The accuracy of the model was verified by the internal force results.Taking the single pier model as an example,the accuracy of the overlanding results under different lateral force distribution patterns is studied,which lays the foundation for the seismic response analysis of bridge structures.(3)Take the self-anchored cable-stayed suspension bridge engineering case as the research object,use the established full-bridge finite element model,calculate the full-bridge displacement,internal force response and hysteretic energy consumption during the improved Pushover analysis and dynamic time history analysis,and analyze the influence of the holding time on the calculation results under different earthquakes,and verify the reliability of the modified Pushover analysis method to simulate the seismic process of the structure,provide a new idea for the analysis of seismic response of complex bridges.(4)By analyzing the degree of stiffness degradation of the bridge tower,which is the main structural member of the bridge,use the single-parameter damage model to evaluate the seismic damage of the cable-stayed-suspension composite bridge,study the seismic performance of the non-linear structure of the bridge tower under different seismic durations.