标题： 沉积盆地内的共振地震运动再审视 显示英文标题

标题： Resonant Seismic Motion Within a Sedimentary Basin Revisited

摘要： 本问题属于二维规范类型，在空间-频率框架中进行研究，涉及一个SH极化的平面体地震波在坚硬、无损耗的半空间（基岩）中传播，该半空间包含一个柔软、有损耗的半圆形盆地。 在盆地内部和外部各点的位移响应，分别以积分形式（适用于一般形状的盆地）和部分波形式（适用于半圆形盆地）表示，积分形式导致一种能量守恒关系的表达式，并解释了入射波提供的能量如何基本上分为两种损失来源：辐射阻尼（发生在基岩中）和体积材料阻尼（发生在盆地内），而部分波形式则能详细地理论证明响应的共振性质，表现为在某些（本征）频率下，位移场在盆地内显著放大和集中，而在其他频率下则几乎没有放大和集中。 这些现象也适用于体积材料阻尼和辐射阻尼的损耗函数（与频率有关），共振位移响应的对应物存在于体积材料阻尼损耗函数的峰值和辐射阻尼损耗函数的谷值中。 本文计算了半圆形盆地在共振和非共振频率下的位移场图，这些图强烈地唤起了其他作者在两篇出版物中针对更现实形状盆地所呈现的数值结果，从而表明本研究的结果在很大程度上适用于一般形状的盆地。 显示英文摘要

摘要： The problem, of 2D canonical nature, examined herein in the space-frequency framework, concerns a SH-polarized plane body seismic wave propagating in a hard, non lossy half space (bedrock) containing a soft, lossy cylindrical basin of semi-circular shape. The displacement response, at points both within and outside the basin is represented alternatively in integral (for basins of general shape) and partial wave (for basins of semi-circular shape) forms, the integral representation leading to an expression of a sort of conservation of energy relation, and an explanation of how the energetic gain provided by the incident wave, is divided essentially into two sources of loss: radiation damping (taking place in the bedrock) and volumic material damping (taking place within the basin), whereas the partial wave representation enables a detailed theoretical demonstration of the resonant nature of the response, marked by amplification and concentration of the displacement field essentially within the basin at certain (eigen-)frequencies and very little, or no amplification and concentration, at other frequencies. These phenomena carry over to the volumic material damping and radiation damping loss functions (of frequency), with the equivalent of resonant displacement response residing in peaks of the volumic material damping loss function and troughs of the radiation damping loss function. Maps, for the semi-circular basin, are computed herein of the displacement field both at resonant and non-resonant frequencies which strongly evoke those (of numerical nature resulting from the boundary element scheme) appearing in two publications by other authors for basins of more realistic shape, so as to suggest that the results in the present study are applicable, for a large part, to basins of general shape.