Normal Transmission of S-Wave Across Parallel Fractures with Coulomb Slip Behavior
Normal Transmission of S-Wave Across Parallel Fractures with Coulomb Slip Behavior
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DOI：
10.1061/(asce)0733-9399(2006)132:6(641
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发表时间：
2006-06
期刊：
影响因子：
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通讯作者：
X. B. Zhao;Jian Zhao;A. Hefny;J. Cai
中科院分区：
文献类型：
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作者：
X. B. Zhao;Jian Zhao;A. Hefny;J. Cai
当弹性波在岩体中传播时，由于裂隙的存在，其振幅减弱，速度减慢。在波传播过程中，当裂缝界面处的剪应力达到裂缝抗剪强度时，裂缝将发生较大的剪切位移。本文研究了具有库仑滑动特性的横波在平行裂缝中的正常传播。在我们的理论公式中，采用特征方法结合库仑滑动模型建立了一套关于粒子速度和剪切应力的递推方程。然后用数值方法求解这些方程。在与理论研究相比较的基础上，采用通用离散元编码（UDEC）进行了数值模拟。UDEC模型与理论分析基本一致。传递系数的大小作为剪切应力比、无因次裂缝间距、归一化剪切刚度和裂缝数量的函数来计算。研究表明，剪应力比是影响波传播的最重要因素，剪应力比较小时，其他因素的影响更为明显。
When an elastic wave propagates through a rock mass, its amplitude is attenuated and velocity is slowed due to the presence of fractures. During wave propagation, if the shear stress at a fracture interface reaches the fracture shear strength, the fracture will experience a large shear displacement. This paper presents a study of the normal transmission of S-waves across parallel fractures with Coulomb slip behavior. In our theoretical formulation, the method of characteristics combined with the Coulomb slip model is used to develop a set of recurrence equations with respect to particle velocities and shear stress. These equations are then solved numerically. In a comparison with the theoretical study, numerical modeling using the universal distinct element code (UDEC) has been conducted. A general agreement between UDEC modeling and theoretical analysis is achieved. The magnitude of the transmission coefficient is calculated as a function of shear stress ratio, nondimensional fracture spacing, normalized shear stiffness, and number of fractures. The study shows that the shear stress ratio is the most important factor influencing wave transmission, and the influence of other factors becomes more apparent when the shear stress ratio is small.