弹性介质中瑞雷面波有限差分法正演模拟

为研究瑞雷面波的形成机理及传播规律，促进瑞雷面波资料处理方法的发展，本文根据弹性波方程，采用交错网格有限差分数值求解算法，对浅层各向同性弹性介质进行了包括瑞雷面波和体波在内的全波场模拟. 提出了变系数吸收边界条件并将之应用于正演模拟，使边界条件的处理简单而高效，同时给出了角点的处理方法. 对工程勘察中常见的连续和层状介质模型进行了模拟，获得了更加接近实际情况的地震记录. 结合模拟记录，探讨了瑞雷面波的形成条件，同时讨论了震源埋深对面波能量的影响.

Finite_difference modelling of Rayleigh surface wave in elastic media

To study the generation mechanism and propagation rule of Rayleigh surface waves, and to accelerate the corresponding development of data processing method, the paper applies the finite-difference method with staggered grids to simulate full-wave-fields, including both Rayleigh surface wave and body waves, in shallow isotropic media based on elastic wave equations. Meanwhile, a variable coefficient absorbing boundary condition, which makes the treatment of boundary condition more simplified and more effective, is developed. Furthermore, a method to process angle points is also proposed. Simulations have been done for continuous and stratified media which are common in the field of engineering survey, and more realistic seismograms are obtained. According to the synthetic records, the condition of Rayleigh surface wave excitation is investigated, and the influence of the depth of epicenter on the energy of surface wave is discussed also.