土层非线性地震反应一维时域分析

1D nonlinear seismic response analysis of soil layers in time domain

等效线性化方法在工程中经常被用于土层非线性地震反应一维数值分析,但考虑大震作用将较大峰值加速度时程作为输入时,该方法会引起过大的"共振"效应,造成对地表地震反应的误估。为了更合理的估计非线性地震反应,提出了一种考虑拟合阻尼比、刚度比试验曲线的时域分析方法,并用于响嘡台阵场地土层地震一维非线性反应分析,通过数值模拟结果与实际记录的比较,验证了该方法的可行性。最后,通过数值模拟证明该方法对大震情况下对地表地震反应的估计比等效线性化方法更为合理。

In engineering region,the equivalent linearization method is often used to the nonlinear seismic response analysis of soil layers in 1 D;but when the large peak acceleration time period is chosen as the computing input for taking account of load on site in large earthquake event,the method brings the remarkable ＂resonance＂ effect,which results to the mistakes in the evaluation to the surface response.For estimating the nonlinear seismic response more exactly,it is recommended to a true nonlinear method in time domain fitting G/ G0-γ curve andλ-γ curve,and using it to 1D nonlinear seismic response analysis of soil layers on Xiangtang Array.In the study,the true nonlinear results of surface seismic response comparing with the results from the equivalent linearization method and actual records,the feasibility of the recommended method is proved.And the numerical studies show that the recommended method is more reasonable than the equivalent linearization method in large earthquake cases.