In order to study the damage law of large-span railway cable-stayed bridges under earthquake actions,a certain railway cable-stayed bridge was taken as the research project.Finite element nonlinear dynamic time history analysis model was established on OpenSees platform,20 artificial synthesized seismic waves were used as seismic motions.Based on the incremental dynamic analysis method,the vulnerability curves of the bridge components under longitudinal and transverse seismic actions were calculated and analyzed for the cable-stayed bridge.The first and second order boundary methods were used to calculate the vulnerability of the bridge system.The results indicate that under longitudinal and transverse seismic actions with PGA of 0.1g,the probability of minor damage is 70％and 85％respectively,and the probability of moderate damage is 40％and 60％respectively,and this means that the lateral failure of the supports occurs before the longitudinal failure.When PGA is less than 0.2g,neither the bridge pier nor the bridge tower will be damaged.However,as the ground motion increases,the probability of damage to the bridge pier under the longitudinal bridge action is greater than that under the transverse bridge action,and the probability of damage to the bridge tower under the longitudinal bridge action is less than that under the transverse bridge action.The maximum difference between the upper and lower boundaries of the first order and second order boundary methods is 0.15 and 0.07 for minor damage,0.03 and 0.06 for moderate damage,0.25 and 0.02 for severe damage,and 0.23 and 0.02 for complete damage.This indicates that the second order boundary method can significantly reduce the spacing between the upper and lower boundaries.
关键词
铁路桥梁/易损性/数值分析/斜拉桥/损伤指标/动力时程分析/界限法
Key words
railway bridge/seismic vulnerability/numerical calculation/cable-stayed bridge/damage indicator/dynamic time history analysis/boundary estimation method
维普
万方数据