节理面透射模型及其隔振性能研究

振动波入射到节理界面上，与软弱断层一样会产生波场的分解，能够起到隔振作用。根据线性变形节理的透反射规律研究发现，隔振后各点的波场可由透射P波与透射S波叠加而成，其能量分配服从Zoeppritz方程，不连续位移造成了透射波的衰减；法向刚度增加透射纵波系数会增加，而切向刚度与透射纵波无关，法向与切向刚度对透射S波均有影响，刚度增加透射S波振幅逐渐降低，逐步逼近于0；由于透射后波场相互干涉，不同波场延时不同，透射合成波与入射波相比，振幅降低，持续时间增加，波形尾段有畸变；总能量系数与节理面的刚度无关，而随入射角增加不断降低。

Transmission model of joint interface and its performance of vibration isolation

Like soft fault, wave field would be separated into several fields if incident wave met joint interface, vibration strength then could be decreased. According to linear deformation joint model, wave transmission and reflection rules are studied. The result indicates that wave filed after vibration isolation is superimposed by transmission P wave and transmission S wave, of which the energy follows Zeoppritz equation, discontinuous displacement at joint interface causes wave attenuation. Higher normal stiffness can make larger coefficients of transmission P wave, while there isn’t connection between tangential stiffness and transmission P wave；both normal and tangential stiffnesses affect the transmission S wave, higher stiffness can make lower amplitude of transmission S wave which approximates to 0 gradually. Due to field interference after transmission, vibration amplitude of transmission composite wave will decrease, duration time will increase, and tail section of waveform will be distorted; total energy coefficient has no connection with joint stiffness, but it decreases with the increase of incident angle.