沉积层序对谷地场地地震反应的影响-SH波入射

发布时间：2018-07-10 04:33

本文选题：沉积谷地 + 场地地震反应　；参考：《土木工程学报》2017年01期

【摘要】：采用一种多域间接边界元方法,求解了层状半空间中多层沉积谷地对平面SH波的放大效应问题。该方法将含有多层沉积的层状半空间分解为开口层状半无限空间域和多个沉积层闭合域,进而通过求解层状半空间中斜线均布荷载动力格林函数来模拟开口域内的散射波场,通过求解全空间中均布荷载动力格林函数来模拟各闭合域的散射波场。方法充分发挥半空间格林函数和全空间格林函数在构造开口半无限空间域和闭合域内散射波场方面的优势,具有灵活性强和精度高的优点。文中验证了方法的正确性,并以正常沉积、软夹层沉积和逆序沉积为例进行了数值计算分析,研究了沉积层序对谷地附近地面运动的影响。数值结果表明,沉积层逆序排列时,低波速层对中高频地震动均有很好的"隔震"效果;沉积层序对地面运动的固有频率和卓越频率均有着显著的影响;沉积序列的改变会导致沉积动力特性的改变,进而会影响到沉积谷地与层状场地的动力相互作用机制。
[Abstract]:In this paper, a multi-domain indirect boundary element method is used to solve the amplification of plane SH waves in layered half-space. In this method, the layered half-space with multi-layer deposition is decomposed into open layered semi-infinite space domain and multiple sediment layer closed domain, and then the scattering wave field is simulated by solving the dynamic Green's function of oblique uniform load distribution in the layered half-space. The scattering wave fields in each closed domain are simulated by solving the dynamic Green's function of uniformly distributed loads in the whole space. The method gives full play to the advantages of semi-space Green's function and full-space Green's function in constructing scattering wave fields in open and semi-infinite space domain and closed domain, and has the advantages of strong flexibility and high precision. The correctness of the method is verified and numerical analysis is carried out by taking normal deposition, soft intercalation deposition and inverse sequence deposition as examples, and the influence of sedimentary sequence on the ground motion near the valley is studied. The numerical results show that the low wave velocity layers have a good "isolation" effect on the ground motion in the middle and high frequency, and the sedimentary sequences have a significant effect on the natural frequency and the excellent frequency of the ground motion. The change of sedimentary sequence will result in the change of sedimentary dynamic characteristics, which will affect the dynamic interaction mechanism between sedimentary valley and layered site.
【作者单位】：天津大学建筑工程学院;天津大学滨海土木工程结构与新材料教育部重点实验室;
【基金】：国家自然科学基金(51578373,51578372)
【分类号】：TU435

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