地震激励下斜拉桥横向支承体系力学参数联合优化

Joint optimization of mechanical parameters of lateral support system of cable stayed bridge under earthquake excitation

以某斜拉桥为算例,通过非线性动力时程分析,研究横向支承体系关键力学参数对结构地震响应的影响。分别运用正交试验设计法和控制变量法对桥墩单向可动支座屈服力和桥塔抗风支座初始间隙进行参数联合优化。结果表明:多因子优化时,控制变量法已无法适用,而正交试验设计法不但有效且计算效率高;双因子优化时,两种方法结果相同,但正交试验设计法可量化参数之间的正交与耦合性。高墩上支座的屈服力与桥塔抗风支座初始间隙具有较强的正交性,互相影响的显著性较低,参数优化时可以单独考虑;矮墩上支座的屈服力与桥塔抗风支座初始间隙表现出较强的耦合性,参数优化时需联合考虑。

Here,taking a certain cable-stayed bridge as an example,effects of key mechanical parameters of its lateral bearing system on structural seismic response were studied through nonlinear dynamic time history analysis.The orthogonal test design method and the control variable method were used,respectively to do joint optimization of mechanical parameters for yield force of one-way movable bearing of bridge pier and initial clearance of anti-wind bearing of bridge tower.The results showed that during multi-factor optimization,the control variable method can’t be used,while the orthogonal test design method is not only effective but also has high calculation efficiency;during two-factor optimization,the results of the two methods are the same,but the latter can quantify the orthogonality and coupling between parameters;yield force of high pier upper bearing and initial clearance of bridge tower anti-wind bearing have stronger orthogonality,while their interaction significance is lower,so they can be considered separately in parametric optimization;yield force of short pier upper bearing and initial clearance of bridge tower anti-wind bearing have stronger coupling,so they should be jointly considered in parametric optimization.