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SINGH M为克服(Mohr-Coulomb M-C)准则只能线性表征岩石强度随围压变化这一局限性,在M-C准则的基础上添加一个修正项对其进行改进,提出非线性M-C准则。该准则认为,岩石在围压达到其单轴抗压强度时岩石就进入临界状态,此观点与部分岩石的试验结果有较大的出入,使得该准则的适用范围受到影响。为拓宽非线性M-C准则的适用范围,通过对其修正项的进一步改进,提出M-C准则修正一般表达式。应用11种岩石三轴试验数据对M-C准则修正一般表达式、非线性M-C准则和目前岩石力学界认为较好的双曲线型准则的精度进行比较,结果显示,M-C准则修正一般表达式对岩石三轴强度的拟合精度高于其他两种准则,且由岩石三轴试验强度的一致性更好。证明M-C准则修正一般表达式优于非线性M-C准则,且适用范围更广。
SINGH M To overcome the limitation that Mohr-Coulomb M-C criterion can only linearly characterize rock strength with confining pressure, a modified term is added to M-C criterion to improve it. A nonlinear M-C criterion is proposed. According to this guideline, the rock enters a critical state when the confining pressure reaches its uniaxial compressive strength. This view has a large discrepancy with the test results of some rocks, which impairs the applicable scope of the criterion. In order to broaden the scope of the application of the nonlinear M-C criterion, M-C criterion correction general expression is proposed by further improving its correction. Eleven kinds of rock triaxial test data are used to compare the general expressions of MC criterion, the accuracy of the nonlinear MC criterion and the hyperbolic criterion considered as good by the rock mechanics community. The results show that the MC criterion corrects the general expression to the accuracy of the rock three The fitting accuracy of the axial strength is higher than the other two criteria, and the consistency of strength by the rock triaxial test is better. It is proved that the general expression of M-C criterion is better than the non-linear M-C criterion and has a wider scope of application.