【摘要】 分别建立了中塔位于谷地和峰顶的输电塔线耦联体系三维空间有限元模型,模拟生成考虑地形变化场地上的多点地震动,运用非线性动力时程分析方法,进行多点地震激励下地形变化输电塔线体系的地震响应数值模拟.考虑多点地震动中的行波效应、部分相干效应和局部场地效应.分析多点地震动中行波效应和局部场地效应对结构地震响应的影响,并将计算结果与一致激励下的结果进行对比.研究结果表明,无论输电塔位于峰顶还是谷底,受行波波速的影响很大,但两种模型受行波波速的影响程度不同,忽略行波效应可能低估体系的地震响应;随着场地条件差异变大,结构的地震响应变大,对于输电塔位于峰顶的响应放大程度要大于输电塔位于谷底,因此应该考虑局部场地效应的影响.更多还原

【Abstract】 Three-dimensional finite element models of transmission tower-line coupled system which the middle transmission towers are located at the summit and valley floor were established,respectively.Multi-support ground motions considering topographic variation site were simulated.Using nonlinear dynamic time history analysis method,seismic responses of the transmission tower-line system considering topographic variation site under multi-support excitations were carried out.Wave passage effect,coherency loss effect and different local site effect of multi-support ground motions were considered.Compared with the structural response under uniform excitation,the responses considering wave passage effect and local site effect of multi-support ground motion were analyzed,respectively.The results showed that the traveling wave velocity had a significant effect on the models that the middle transmission towers are located at the summit and valley floor,but the degrees of the effect were different for two models.Neglecting the wave passage effect could underestimate the seismic response of the system.The larger are the difference between the site conditions,the larger are the responses of the structure.The responses of the middle transmission tower located at the summit are larger than that located at valley floor.Therefore,the influence of the local site effect should be considered.更多还原