Seismic Research Of Long-span Continuous Rigid Frame Bridge With High-rise Piers Based On The Pushover Analysis

Earthquakes cause serious casualties and economic losses, the earthquakedamage in the bridge structure bring a serious impediment to the earthquake reliefwork. The bridge seismic is rarely researched in our country, especially in long-spancontinuous rigid frame bridge with high-rise piers in the southwest, far less than theactual project requirements, it brings great difficulties and economic waste forengineering seismic. This paper uses the nonlinear static (Pushover analysis method)analysis method, which is based on the performance-based seismic design, to discussthe applicability of Pushover analysis method to evaluate the seismic performance oflong-span continuous rigid frame bridge with high-rise piers. This paper mainlycompleted the following several aspects.(1) Made a full investigation of main bridge seismic damage both at home andabroad; reviewed the development course of seismic design theory and theperformance-based seismic design method; summarized the statue quo of Pushoveranalysis method in long-span bridges with high-rise piers.(2) Detailed summary of basic principle and implementation steps of Pushoveranalysis method has made, and put forward some problem existing in the twoassumptions for Pushover analysis when evaluating bridge seismic performance. Listsfive fixed type of lateral load distribution form which is widely used, and put forwarda load distribution form which considering the quality of the upper structure.(3) Process fixed type modal Pushover analysis and adaptive modal Pushoveranalysis for different high-piers bridge as well as Pushover analysis with six kinds offixed type lateral load distribution form. By comparison the results showed that thedistribution of modal combination (form6) is a reasonable form of lateral loaddistribution, which including the influence of high-order vibration mode as well aslumped mass block on the upper structure, can get a good result. Self-adaptive modalPushover analysis, which considering the impact of the higher order modes and theeffect of plastic state on the change of distribution form, can get more accurateresults.(4) When evaluating the seismic performance of80m high pier bridge structureunder the form six, we can get the results that the bridges meet the seismicrequirements.