Experimental Study on Shear mechanism of Rock Discontinuities

本项目取得的主要成果如下：1.在常法向应力条件下进行岩石结构面剪切试验后，发现结构面表面粗糙度在比定义的法向应力更高的频率区域发生断裂.随着剪切位移的发展，岩体结构面表面粗糙度的破裂发生在高频分量，并向低频分量发展。但在极限频率下，材料的韧性会发生爬升，这与正应力有关.在一定位移下的剪切强度取决于粗糙度分量的强度，其中破裂主要发生。在粗糙度发生爬升的情况下，剪切强度保持恒定。这对应于剩余强度。表面粗糙度的断裂直到剪切强度峰值出现才发生。在峰值强度下，断裂立即发展到一定程度的高频粗糙度.伴随剪切位移的法向膨胀还取决于破裂主要发生的粗糙度分量，或越过粗糙度的极限频率。

Main results obtained in this project are following.1. It is observed that the surface roughness of discontinuities in the higher frequency region, than the defined one depend on the normal stress, are fractured, after the shear test of rock discontinuities under the condition of the constant normal stress.2. Progressing the shear displacement, the fracture of the surface roughness of rock discontinuities occurs in the high frequency components, and develops to the lower components. But the climb over the toughness occurs at the limit frequency depend on the normal stress.3. The shear strength at a certain displacement, depends on the strength of the roughness components, in which fracture is occurring mainly. In the case that the climb over the roughness occurs, the shear strength is kept constant. This corresponds to the residual strength.4. The fracture of the surface roughness does not occur, until the peak shear strength appears. At the peak strength, the fracture develops at once to the some extent of higher frequency roughness.5. The normal dilatation accompanied with the shear displacement, also depends on the roughness components in which fracture is occurring mainly, or the limit frequency of the climb over roughness.