平面SH波作用下部分充填圆弧形沉积谷的二维土层和地形放大效应

发布时间：2018-03-21 07:10

本文选题：二维土层效应　切入点：地形效应　出处：《地震学报》2017年05期 　论文类型：期刊论文

【摘要】：场地效应通常包含土层放大效应和地形放大效应,为了揭示二者的相对贡献,本文构造了平面SH波作用下部分充填沉积谷的解析模型,借助于区域分解策略,在波函数展开法的框架下,提出了超定方程组解法,得到了部分充填圆弧形沉积谷对平面SH波散射的波函数级数解,而且级数解的收敛测试表明了超定方程组解法的必要性.通过与文献结果进行对比,验证了本文方法的正确性.通过调整解析模型中两个子区域内的材料参数,计算了沉积谷引起的场地放大效应和相应的空河谷引起的地形放大效应.对二维土层与地形效应进行对比分析,结果显示,在沉积谷内二维土层放大效应通常强于地形放大效应,而地形放大效应决定了沉积谷外的地面运动放大形态.针对最大地面运动,进行了沉积谷和相应空河谷的参数分析,进一步描述了二维土层放大效应,研究结果表明二维土层放大效应引起的最大地面运动通常远远大于地形放大效应引起的最大地面运动,并且二维土层效应通常随着土层与基岩的阻抗比的增大而增大,但不是一维土层放大效应与二维地形放大效应的简单线性叠加.
[Abstract]:In order to reveal their relative contribution, an analytical model of partially filling sedimentary valleys under the action of plane SH waves is constructed, which is based on the regional decomposition strategy. In the framework of wave function expansion method, a solution to overdetermined equations is proposed, and a series of wave function solutions for scattering of plane SH waves by partially filled circular arc depositional valleys are obtained. Moreover, the convergence test of the series solution shows the necessity of solving the overdetermined equations. The correctness of the method is verified by comparing with the results of the literature. The material parameters in the two sub-regions of the analytical model are adjusted. The site magnification effect caused by sedimentary valley and the terrain magnification effect caused by corresponding hollow valley are calculated. The magnification effect of two-dimensional soil layer in the sedimentary valley is usually stronger than that of the topographic amplification effect, and the topographic amplification effect determines the magnification form of the ground motion outside the sedimentary valley. The parameters of the sedimentary valley and the corresponding empty valley are analyzed for the maximum ground motion. The results show that the maximum ground motion caused by the two-dimensional soil layer amplification is much larger than the maximum ground motion caused by the topographic amplification effect. And the two-dimensional soil layer effect usually increases with the increase of the impedance ratio of the soil layer to the bedrock, but it is not a simple linear superposition of the one-dimensional soil layer amplification effect and the two-dimensional topographic amplification effect.
【作者单位】：河海大学岩土力学与堤坝工程教育部重点实验室;河海大学土木与交通学院岩土工程科学研究所;
【基金】：国家自然科学基金(51608172,41630638,51479050) 国家重点基础研究发展计划(973)(2015CB057901) 水利部公益性行业科研专项(201501035-03) 国家重点研发计划项目(2016YFC0800205) 中央高校基本科研业务费(2015B01214)联合资助
【分类号】：P315.9;TU435

【相似文献】