大跨度矮塔斜拉桥地震响应优化分析

Optimization analysis of seismic response of long-span low-rise tower cable-stayed bridge

为了研究地震响应下各优化变量对矮塔斜拉桥整体抗震性能的影响程度,该文以温州某特大桥为依托,对各设计参数进行动力响应优化。以双肢薄壁墩墩间距、墩厚、边主跨比以及主塔高度为变量,以E1弹性时程作用下墩底抗弯能力需求比最小和E2弹塑性时程作用下墩底延性转角需求比最小以及疲劳损伤系数最小为优化目标,运用动力时程分析方法,对均匀试验下的参数组合试验模型进行计算分析,采用TOPSIS理想点法进行多目标优化,得出最优试验组合和不同设计参数对试验的影响程度。结果表明:弹性阶段中,1#试验组合墩底抗弯需求比最优;在弹塑性阶段,墩底抗弯需求比目标函数下边主跨比对试验影响程度最大,疲劳损伤系数目标函数下薄壁墩厚度对试验影响程度最大;基于TOPSIS理想点法的多目标优化下最优组合为4#试验组合。研究结果为矮塔斜拉桥的优化研究、抗震设计等提供参考。

In order to study the influence of various optimization variables on the overall seismic performance of the low-rise cable-stayed bridge under seismic response,based on a special bridge in Wenzhou,the dynamic response of each design parameter is optimized.Taking the distance between the thin-walled piers of the two limbs,the thickness of the pier,the ratio of the main span of the side and the height of the main tower as the variables,the required ratio of the bending resistance of the pier under the E1 elastic time history and the ductile angle of the bottom of the pier under the E2 elastoplastic time history,the minimum demand ratio and the minimum fatigue damage coefficient are the optimization objectives.The dynamic time history analysis method is used to calculate and analyze the parameter combination test model under uniform test,the TOPSIS ideal point method is used for multi-objective optimization to obtain the optimal test combination and different,and the extent to which design parameters affect the test.The results show that in the elastic stage,the bending resistance demand ratio of the 1#test combination pier bottom is optimal;in the elastoplastic stage,the bending resistance requirement of the pier bottom is the most affected by the lower main span test of the objective function,and the fatigue damage coefficient objective function is thin,the thickness of the pier has the greatest impact on the test;the optimal combination under the multi-objective optimization based on the TOPSIS ideal point method is the 4#test combination.The research results provide reference for the optimization research and seismic design of the low-rise cable-stayed bridge.