基于霍克-布朗(Hoek-Brown)准则重力坝抗滑稳定分析

The deep anti-sliding stability analysis of gravity dam based on Hoek-Brown failure criterion

霍克-布朗(Hoek-Brown)强度准则因其能准确描述岩体、岩石的破坏特征而得到广泛应用。以ABAQUS为平台,利用完全隐式欧拉回映算法进行应力更新,建立相应的一致切线刚度矩阵,开发了基于Hoek-Brown强度准则的UMAT本构模型,并通过单轴压缩和拉伸数值试验验证了程序的可靠性和准则的适用性。最后,基于编制的UMAT与等效Mohr-Coulomb准则,采用超载法进行重力坝深层抗滑稳定分析。计算结果表明:等效Mohr-Coulomb准则高估了岩体抗拉强度,Hoek-Brown准则能反映岩体的非线性破坏特征,更符合坝基岩体的实际特征.

Hoek-Brown failure criterion is widely used because it can accurately describe the failure characteristics of rock masses.Based on ABAQUS,the Euler backward integration method is used to update plastic stress;and consistent stiffness matrix is established.The UMAT subroutine of the Hoek-Brown model is developed and verified by uniaxial compression and tensile tests.Finally,based on the UMAT and equivalent Mohr-Coulomb criterion,deep anti-sliding stability analysis of gravity dam is performed by using overloading method.The results show that equivalent Mohr-Coulomb criterion overestimates the strength of rock mass.Hoek-Brown criterion can reflect the nonlinear failure characteristics of rock mass and conform to the actual characteristics of the rock mass.