基于统计损伤理论的德鲁克-普拉格岩石强度准则的修正

德鲁克-普拉格强度准则是目前岩石力学中广泛应用的岩石强度准则之一，其计算结果较为保守，与实际存在差距，为此本文深入探讨了其修正方法。研究方法是在前人岩石损伤软化统计本构模型研究的基础上，通过探讨不同围压条件下模型参数与围压的关系,对模型进行修正，然后，根据岩石屈服或破坏的概念，利用岩石变形软化全曲线的极值特性，采用多元函数求极值的方法建立岩石强度理论，从而对德鲁克-普拉格岩石强度准则进行修正。修正后的德鲁克-普拉格准则能反映体积应力、剪应力、中间主应力和最小主应力对岩石强度的影响，同时还可以反映岩石强度莫尔包络线的曲线特征，它与试验结果吻合良好。工程实例计算表明，该强度准则能更好地反映工程实际。

Modified Drucker-Prager strength criterion based on statistical damage theory for rock

The Drucker-Prager strength criterion for rock is relatively conservative and obviously deviates from reality. In this paper the modification of this criterion is studied. Firstly, the existing statistical damage softening constitutive model for rock is modified according to the relationship between model parameters and confining pressure. On this basis, the Drucker-Prager criterion is modified by using the method for calculating the extremity of pluralistic function according to the extremity characteristics of rock deformation softening curve. The modified criterion comprehensively reflects the effects of volume stress, shear stress and major stress on rock strength. The calculation result by using this modified criterion well agrees with experimental data.