岩石材料破坏形式的分叉分析

BIFURCATION ANALYSIS ON FAILURE FORMS OF ROCK MATERIAL

采用不连续分叉理论,分析了轴对称状态下岩石材料的破坏形式,并采用一组大理岩的实验结果进行了模拟计算。分析结果认为,岩石材料在单轴压缩状态下的脆性破坏总是张破裂的,而在常规三轴压缩状态下的脆性破坏是剪切破坏的,并且随着围压的增加,其剪切带方位角逐步降低,破坏形式由剪切破坏逐步向塑性破坏过渡。此外,岩石材料的剪切带分叉发生在峰值应力之后,随围压增加而逐步远离峰值点。

The failure forms of rock materials in axisymmetric compression are studied based on the discontinuous bifurcation theory, and a set of experimental data of marbles are simulated. The results show that the brittle fracture form of rock in uniaxial compression is always the tensile fracture, and that of rock in routine triaxial compression is the shear fracture. The inclination angle of the shear band would decrease in steps with the increment of lateral pressure. Furthermore, the localization shear band bifurcation takes place at the point in the strain softening area, and the point would be far from the peak point with the increment of lateral pressure.