【摘要】 采用等效线性化技术考虑土的动力非线性特性,利用一维波传法及SHAKE91软件计算水平成层场地的地震反应,研究了土的动剪模量比和阻尼比与剪应变幅值的关系曲线、土层剪切波速的变异性对深软场地地表峰值加速度及其反应谱的影响。结果表明:土的动剪模量比均值加1倍标准差与阻尼比均值减1倍标准差、动剪模量比均值减1倍标准差与阻尼比均值加1倍标准差的组合对地表峰值加速度的影响最为显著,但对地表加速度反应谱形状的影响不大;土层剪切波速15%的变异性对地表加速度反应谱形状有较大影响;土层剪切波速的变异性对地表加速度和反应谱的影响比动剪模量比和阻尼比变异性的影响更为显著。更多还原

【Abstract】 Considering nonlinear dynamic characteristics of soils by equivalent linearization method, site earthquake response analysis with horizontal-layered soil are analyzed on the basis of the one-dimensional wave motion model by SHAKE91 software, and we discussed the effects of the variability of soil dynamic parameters, including soil dynamic shear modulus ratio, damping ratio and shear velocity, on peak value of ground surface acceleration and its response spectra of deep soft sites. The conclusions are shown by using numerical results obtained from many case studies. The following combinations cause the most prominent effect on peak value of ground surface acceleration: the mean value of dynamic shear modulus ratio added by one standard deviation with the mean value of damping ratio reduced by one standard deviation; the mean value of dynamic shear module ratio reduced by one standard deviation with the mean value of damping ratio added by one standard deviation, but they cause negligible effect on the shape of the acceleration response spectra. And the 15% variability of shear velocity of strata makes more effect on the shape of the response spectra of ground surface acceleration. By comparison of calculation results, the variability of shear velocity of soil layers causes more prominent effect on the value of ground surface acceleration and its response spectra than the variability of dynamic shear modulus ratio and damping ratio do.更多还原