黏弹性节理岩体中应力波的传播特性分析

为探究黏弹性节理对应力波在岩体中传播规律的影响，引入饱依丁-汤姆逊模型作为位移不连续条件，基于时域递归方法推导出应力波通过一组平行黏弹性节理的传播方程；通过将饱依丁-汤姆逊模型退化为Maxwell模型和Kelvin模型所得的时域递归数值解与已有的频域内封闭解对比，验证推导过程的正确性；最后，对相关参数的影响规律进行分析。结果表明：模型无量纲系数、无量纲节理厚度、无量纲节理间距和入射角等都对波的传播产生影响；对于单条节理，应力波的透反射系数以及能量耗散率主要取决于位移不连续模型的无量纲参数、入射角及无量纲节理厚度；而对于一组平行节理，透射系数还和平行节理数与节理间距的大小有关，且节理条数的增加对入射临界角位置处透射波振幅的衰减影响更为明显。

Analysis of propagation characteristics of stress waves in viscoelastic jointed rock mass

To explore the influence of viscoelastic joint on the propagation law of stress waves in rock mass, the Poyting-Thomson model was introduced as the discontinuous displacement condition, and based on the time-domain recursive method, the propagation equation of the stress waves through a set of parallel viscoelastic joints was derived. Then, the time-domain recursive numerical solutions obtained by degrading the Poyting-Thomson model to the Maxwell model and the Kelvin model were compared with the existing closed-form solutions in the frequency domain to verify the validity of the derivation process. Finally, the influences of relevant parameters were further analyzed. Results show that the non-dimensional coefficients, joint thickness, joint spacing and incident angle of the model all affected the wave propagation. For a single joint, the transmission and reflection coefficient along with the energy dissipation rate of the stress waves mainly depended on the non-dimensional parameters, the incident angle, and the non-dimensional joint thickness of the displacement discontinuity model. For a group of parallel joints, the transmission coefficient was also related to the number of parallel joints and the size of the joint spacing. Besides, the increase in the number of joints had an obvious attenuation effect on the amplitude of the transmitted wave at the critical incident angle.