正则抛物线准则及岩石初始损伤的估计

Normal parabolic criterion and estimation of initial damage of rock

岩石内存在裂隙等缺陷引起试样强度的离散。随着围压增加,裂隙的摩擦承载与黏结力差异减小,即初始损伤对高围压下强度影响较小。正则抛物线准则可以准确描述砂岩等颗粒性岩石在高围压下的强度,拟合参数视为岩石的理想单轴压缩强度,其与试验值的差异表征试样初始损伤度。该参数可以为岩石损伤力学分析提供基础。

The fissures in rock induce scattering strengths of specimens. However, the supporting capacity of the fissures from friction will increase up to the cohesion as the confining pressure increases. Therefore, the influence of the initial damage in rock should be less on the strengths under high confining pressures. Those strengths of granular rocks like sandstone can be fitted using the normal parabolic criterion. The parameter in the criterion is the ideal uniaxial compressive strength, and its difference with the practical test data shows the initial damage in rock. It is applicable as a key parameter in the rock damage mechanics.