连续屈服节理模型对剪切地震波传播的影响

地震波在跨越岩体中节理时的透反射特性是岩石地下工程抗震分析问题中的重要基础，目前开展的研究工作中尚未有针对连续屈服（CY）非线性节理模型透反射特性的研究报导。在前人提出的非线性节理透反射系数时域递归法解答的基础上，将这一方法拓展至CY模型。并采用3DEC离散元软件，对比了CY模型的时域递归解与数值模拟结果的差异。在此基础上以时域递归解为手段，辅以离散元数值模拟，开展了CY模型的参数影响研究。最终比较了库仑（MC）模型与CY模型在正弦脉冲激励和真实地震动激励下表现的差异。结果表明：CY模型的时域递归解与3DEC数值模拟结果显示了良好的一致性，证明了时域递归解用以进行后续参数研究的合理性。法向应力、入射波幅值、节理初始刚度、节理间距等参数对CY模型具有显著影响。相比库仑模型，连续屈服模型可以更好地反映地震波穿越节理时发生的复杂力学现象，如切向刚度退化、抗剪强度劣化、法向应力依赖性、滞回现象等。研究成果可为岩石地下工程的抗震设计与分析工作提供一定参考。

Transmission of S-wave across one joint using the continuously yielding model

It is important to consider an aseismic issue, which is that transflective properties of the seismic wave propagating through joints embedded in rock in underground rock engineering. However, there is very limited research on transflective properties by using the continuously yielding nonlinear joints model. In this paper, a continuously yielding (CY) model was developed based on the time-domain recursive method (TDRM) for S wave using a nonlinear Coulomb-slip (MC) model. Verification of TDRM-based results was conducted in comparison with the simulated results via 3DEC code. Meanwhile, the influence parameters were also discussed. Finally, the results from MC model and CY model were compared under an idealised impulse excitation and a real ground motion record, respectively. It can be seen that TDRM-based results show good agreement with the simulated results by 3DEC, which proves that TDRM is reliable to study the subsequent parameters. In addition, CY model is significantly influenced by parameters of normal stress, incident wave amplitude, initial joint stiffness and joint spacing, respectively. Compared with MC model, CY model can better describe complex joint behaviours in the wave propagation, such as tangential stiffness degradation, shear strength deterioration, normal stress dependence and the hysteresis effect. Therefore, research results can provide useful references for the seismic design and analysis of rock underground engineering.