Fracture interface waves
Fracture interface waves
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断裂界面波
DOI：
10.1029/95jb02846
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发表时间：
1996
影响因子：
--
通讯作者：
L. Pyrak‐Nolte
中科院分区：
文献类型：
--
作者：
Boliang Gu;K. Nihei;L. Myer;L. Pyrak‐Nolte
本文用平面波分析和边界元法研究了弹性固体中单裂纹上的界面波。断裂的有限机械刚度被建模为位移不连续性。分析非均匀平面波沿沿着裂缝传播时，得到对称和反对称界面波的两个色散方程。这些方程的基本形式是类似于经典的瑞利方程的表面波在半空间，除了对称和反对称断裂界面波的位移和速度分别由一个归一化的断裂刚度控制。对于较低的归一化断裂刚度值，对称和反对称界面波退化为经典的瑞利波的无摩擦表面。对于大值的归一化断裂刚度，反对称和对称的界面波分别成为体S波和体P波，其平行于断裂传播。对于归一化断裂刚度的中间值，两个界面波都是色散的。使用边界元法进行的数值模拟表明，线源产生的P型界面波，除了两个瑞利型界面波。归一化断裂刚度的大小被观察到控制界面波的速度和断裂附近的各种波之间的地震能量的分配。
Interface waves on a single fracture in an elastic solid are investigated theoretically and numerically using plane wave analysis and a boundary element method. The finite mechanical stiffness of a fracture is modeled as a displacement discontinuity. Analysis for inhomogeneous plane wave propagation along a fracture yields two dispersive equations for symmetric and antisymmetric interface waves. The basic form of these equations are similar to the classic Rayleigh equation for a surface wave on a half-space, except that the displacements and velocities of the symmetric and antisymmetric fracture interface waves are each controlled by a normalized fracture stiffness. For low values of the normalized fracture stiffness, the symmetric and antisymmetric interface waves degenerate to the classic Rayleigh wave on a traction-free surface. For large values of the normalized fracture stiffness, the antisymmetric and symmetric interface waves become a body S wave and a body P wave, respectively, which propagate parallel to the fracture. For intermediate values of the normalized fracture stiffness, both interface waves are dispersive. Numerical modeling performed using a boundary element method demonstrates that a line source generates a P-type interface wave, in addition to the two Rayleigh-type interface waves. The magnitude of the normalized fracture stiffness is observed to control the velocities of the interface waves and the partitioning of seismic energy among the various waves near the fracture.