非线性准则下节理岩体稳定性的屈服接近度分析

Yielding approach index analysis for stability of joint rock mass based on nonlinear criterion

为了将Barton-Bandis非线性破坏准则与岩体稳定性判断标准的屈服接近度相结合,推导Barton-Bandis准则强度参数和Mohr-Coulomb线性破坏准则强度参数之间的关系,然后,通过算例分析,讨论Barton-Bandis准则参数对于节理岩体屈服接近度的影响,得到Barton-Bandis参数表征的屈服接近度YAIbb。研究结果表明:YAIbb随节理粗糙系数JRC的增大而减小,JRC越大,岩体节理面越粗糙,岩体的稳定性越高,二者的关系符合线性特征;YAIbb随节理岩体压缩强度JCS的增大而减小,JCS越大,岩体的单轴压缩强度越大,则岩体越致密,强度越高,稳定性越大,破坏的概率越小,二者的关系可用指数方程进行描述。

In order to combine the advantages of Barton-Bandis nonlinear failure criterion and yielding approach index of rock classifying standard,firstly,the relationship between parameters of Barton-Bandis nonlinear failure criterion and Mohr-Coulomb linear failure criterion was deduced;then according to the calculation example analysis,the effects of Barton-Bandis criterion parameters on the yielding approach index of joint rock mass were discussed.The results show that the yielding approach index YAIbb described by Barton-Bandis criterion parameters can be obtained according to the theoretical calculation;YAIbb decreases with the increase of joint roughness coefficient JRC,and the larger the JRC is,the more rough the rock mass joint plane is,which leads to the higher stability of rock mass,and the relationship between YAIbb and JRC can be described by linear equation;YAIbb decreases with the increase of jointed rock compressive strength JCS,that is because,the high JCS is caused by the high axial strength of rock mass,which will leads to greater density of rock mass with high strength,high stability and lower probability of failure,and the relationship between YAIbb and JCS can be described by exponential equation.