一般三轴压缩下岩石的流动和破裂

Flow and Fracture of Rocks under General Triaxial Compression

在此回顾一下岩石承受一般三轴压缩时流动和破裂的近代实验研究概况.由于实验技术的新发展,使得有可能测得在一般三轴应力状态下的三个主应力和主应变,此处三个主应力彼此是不相等的.各向同性岩石的强度和延性不仅明显地受最小主应力σ_3的影响,而且也受中间主应力σ_2的影响,尽管这两者增大都可使强度提高,但对延性这两者的效果却恰好相反.实验结果表明.在一般三轴应力状态下,岩石的膨胀呈现显著的各向异性.本文还研究了各向异性岩石在一般三轴应力状态下的变形特性.在此情形中,中间主应力的效果主要取决于软弱面的方位.

Recent laboratory studies of the flow and fracture of rocks under general triaxial compression are reviewed. New developments in laboratory techniques have made it possible to measure three principal stresses and strains under general triaxial stress states, in which all three principal stresses are different.Strength and ductility of isotropic rocks are markedly affected not only by the least compression but also by the intermediate compression although these two effects are rather additional in strength, but opposite in ductility. The experimental results show that dilatancy is highly anisotropic under the general triaxial stress states.Deformational properties of anisotropic rocks have been also measured under the general triaxial compression. In this case, the effect of the intermediate compression markedly depends on the orientations of the weak planes.