基于一种应力不变量组合的岩石强度准则

Strength Criterion of Rock Based on a Stress Invariant Combination

针对深部高地应力条件下岩石的破坏机制,建立起一个基于一种应力不变量组合的岩石非线性强度准则。这个应力不变量组合将任意应力状态分解成三个部分:一部分表示最大剪切状态,另一部分代表静水压力状态,最后一部分补充中间主应力的影响。它能解释粘性和塑性介质不可回复变形模型中能量耗散(弥散)的物理机理。该强度准则考虑岩石的拉伸破坏,可同时描述岩体的剪胀或剪缩破坏,其破坏面可以是闭合的也可以是张开的,其子午线能反映高应力状态下的岩石非线性。与两种典型应力状态的试验数据进行了比较,符合较好。

A nonlinear strength criterion based on a certain stress invariant combination was established to study the failure mechanism of rock in high-stress condition at great depth. Each stress state could be decomposed into three parts with the stress invariant combination ： one was the maximum shear stress state ; another was the hydrostatic stress state and the last one supplemented effect of intermediate principal stress. This combination might be used to explain physical mechanism of energy dissipation in irreversible deformation processes of viscidity and plasticity medium. The strength criterion has taken the rock tensile failure into account, it also considered shear dilatancy damage and shear reduction damage of the rock, which failure plane might he close or open. Meridian line of the strength criterion could reflect nonlinear character of rock in high-stress condition. The computing results with the criterion were compared with data from two kinds of typical rock tests, and the former matched well with the latter.