钢混组合梁减隔震抗震优化设计分析

Analysis of Seismic Isolation and Aseismic Optimization Design of Steel-concrete Composite Beams

为确保钢混组合梁抗震设计性能最优,依托黄江跨航道主跨为138 m的大跨度槽型钢混组合连续梁桥,针对减隔震支座多参数进行优化研究,选择支座尺寸、铅芯直径以及硬化率作为分析参数,分别选取墩底纵向弯矩和横向弯矩两个指标作为目标函数,定义结构综合目标函数W。基于正交试验方法的参数分析,确定钢混组合梁桥抗震性能最优参数组合。采用极差分析法对W进行分析,获得结构设计参数对抗震性能的敏感性及显著性。结果表明,钢混组合梁桥抗震性能最优减隔震支座参数为:减隔震支座尺寸为1 300 mm×1 300 mm,铅芯直径为190 mm,硬化率为0.20,较原设计方案纵向墩底弯矩减小了41.9%,横向墩底弯矩减小了30.5%;参数敏感性程度由强到弱依次为支座尺寸、硬化率、铅芯直径。

In order to ensure the optimal seismic design performance of steel-concrete composite beams,this paper takes the long-span trough steel composite continuous beam bridge with the main span of 138 meters across the channel of Huangjiang River as an example to optimize the multiple parameters of the seismic isolation bearing.The bearing size,lead core diameter and hardening rate are selected as the analysis parameters,and the longitudinal bending moment and transverse bending moment at the bottom of the pier are selected as the objective function.Define the structure synthesis objective function W.Firstly,based on the parameter analysis of orthogonal test method,the optimal parameter combination of seismic performance of steel-concrete composite beam bridge is determined.Secondly,the range analysis method is used to analyze W,and the sensitivity and significance of structural design parameters to seismic performance are obtained.The results show that the optimal seismic performance of the steel-concrete composite beam bridge is as follows:the bearing size is 1300 mm×1300 mm,the lead core diameter is 190 mm,the hardening rate is 0.20,and the bending moment of the longitudinal pier bottom is reduced by 41.9%and the transverse pier bottom is reduced by 30.5%compared with the original design scheme.The sensitivity degree of the parameters from strong to weak is the size of the support,the hardening rate and the diameter of the lead core.