RESEARCH ON TRANSMISSION BEHAVIORS OF NONLINEAR JOINTS WITH 2D WAVE PROPAGATION
二维波穿过非线性节理面的透射性能研究

Two-dimensional wave propagation through joints is a complicated problem. The important factors influencing the transmissivity of joint include normalized stiffness of joints,ray angle,radial distance,joint parameters,incident wave frequency,etc.. Under help of 3DEC,the propagation of 2D wave through single joint with nonlinear joint model,the rules of transmissivity under different strength parameters and geometric positions are studied. According to the research results of single joints,transmissivity of 2D wave through straight joint interface is not only associated with normal and shear stiffness of joint,but also controlled by the joint strength parameters,cohesion and inner friction angle. Values of joint cohesion and inner friction angle reflect the closure degree of joint,which causes transmissivity to take on different tendencies. If the inner friction angle keeps constant,transmissivity will increase with the increase of cohesion strength until it reaches to a superior limit. While if the cohesion keeps constant,transmissivity is different in response to cohesion. If the cohesion is at a low level,the transmissivity will increase with the increase of inner friction angle until it reaches to a superior limit. However,the transmissivity will initiate at a high value then decrease rapidly to a lower level with the increase of the inner friction angle if the cohesion is at a high level. Finally,calculations of transmissivity under the condition of multiple joints are tentatively conducted according to the single joint research results;and some useful comparison works are achieved in dynamic response under complicated joints distribution.