Abstract

The triaxial compression tests under different hydraulic pressures and low confining pressure were carried out to study the hydraulic pressure effect on the mechanical properties and permeabilities of layered rock mass. In general, the results show that the increase of hydraulic pressure reduces the peak strength of layered rock mass and the layer structure changes the mechanical properties of rock mass. With the increase of hydraulic pressure, the peak strength of layered rock mass decreases sharply and then slows down. The peak permeabilities of layered rock mass occurred later than the time when the strength come to the peak. The increase of hydraulic pressure will accelerate the propagation of cracks and significantly enhance the peak permeability of layered rock mass. With the increase of the layer number, the effect of hydraulic pressure becomes more distinct. The initial permeability and the peak permeability increase largely. The increase of hydraulic pressure promotes the expansion and penetration of cracks, so the rock mass develops from tensile failure to the composite failure forms including shear failure and interfacial shear slip failure.

摘要

开展不同水压和低围压下的三轴压缩试验，研究水压对层状岩体力学性质和渗透率的影响。总的来说，结果表明，水压的增加降低了层状岩体的峰值强度，层状结构改变了岩体的力学性质。随着水压的增加，层状岩体的峰值强度急剧下降，然后减缓。层状岩体渗透率峰值出现的时间晚于强度达到峰值的时间。水压的增加会加速裂缝的扩展，显着提高层状岩体的峰值渗透率。随着层数的增加，液压的作用变得更加明显。初始渗透率和峰值渗透率大幅增加。水压的增加促进了裂隙的扩展和贯通，使岩体由拉伸破坏发展为剪切破坏和界面剪切滑移破坏等复合破坏形式。