Three-dimensional fluid-driven stable frictional ruptures
Three-dimensional fluid-driven stable frictional ruptures
复制标题
DOI：
10.1016/j.jmps.2021.104754
复制
发表时间：
2022-01-12
影响因子：
5.3
通讯作者：
Viesca, Robert C.
中科院分区：
文献类型：
--
作者：
Saez, Alexis;Lecampion, Brice;Viesca, Robert C.
我们调查的准静态增长的流体驱动的摩擦剪切裂纹，传播在混合模式（II+III）的平面断层界面，分离两个相同的半空间的三维固体。断层界面的特征在于剪切强度等于恒定摩擦系数和局部有效正应力的乘积。将流体注入断层界面，考虑了两种不同的注入方案：定体积速率注入和定压力注入。我们推导出的解析解发生在泊松比V = 0的限制和数值求解的更一般的情况下，破裂形状是未知的（V 0）的圆形破裂。对于恒定体积速率的注入，断层滑动增长是自相似的。破裂半径（v = 0）扩展为R（t）= lambda L（t），其中lambda（t）是流体压力前沿的标称位置，A是放大因子，其是唯一无量纲参数T的已知函数。后者被定义为在环境条件下失效距离与注射强度之间的比率。当λ> 1时，破裂前缘超过流体压力前缘。对于v # 0，破裂形状为准椭圆形。对于临界应力断层（λ）的极限情况，纵横比的上限和下限分别为1/（1 - v）和（3 - v）/（3 - 2 v
We investigate the quasi-static growth of a fluid-driven frictional shear crack that propagates in mixed mode (II+III) on a planar fault interface that separates two identical half-spaces of a three-dimensional solid. The fault interface is characterized by a shear strength equal to the product of a constant friction coefficient and the local effective normal stress. Fluid is injected into the fault interface and two different injection scenarios are considered: injection at constant volume rate and injection at constant pressure. We derive analytical solutions for circular ruptures which occur in the limit of a Poisson's ratio v = 0 and solve numerically for the more general case in which the rupture shape is unknown (v &NOTEQUexpressionL; 0). For an injection at constant volume rate, the fault slip growth is self-similar. The rupture radius (v = 0) expands as R(t) = lambda L(t), where lambda(t) is the nominal position of the fluid pressure front and A is an amplification factor that is a known function of a unique dimensionless parameter T. The latter is defined as the ratio between the distance to failure under ambient conditions and the strength of the injection. Whenever lambda > 1, the rupture front outpaces the fluid pressure front. For v # 0, the rupture shape is quasi-elliptical. The aspect ratio is upper and lower bounded by 1/(1 - v) and (3 - v)/(3 - 2v), for the limiting cases of critically stressed faults (lambda