石英云母片岩力学性质各向异性的模拟方法探讨

A discussion on the numerical simulation of mechanical properties' anisotropy of Danba quartz mica schist

针对丹巴水电工程中的石英云母片岩力学性质的各向异性问题,以专门的多角度加载室内试验数据为标定依据,对离散元方法、合成岩体方法和基于节理岩体的连续介质方法 3种可以描述岩石力学各向异性的数值模拟方法的适用性分别进行详细讨论。室内试验结果表明:石英云母片岩的变形、强度及破坏形态均随加载方向变化而改变,以加载方向与片理面斜交时最弱。3种数值模拟方法均能有效从数值方法角度模拟石英云母片岩力学特性的各向异性特征,但各自具有不同的特点与适用范围。根据讨论结果,选取计算效率较高的基于节理岩体模型的连续介质方法对CPD-1探洞进行开挖模拟。模拟结果与实际监测得到的围岩松动圈分布相符合,正确体现了石英云母片岩中片理面对围岩破坏模式及位置的控制性作用。

The nature of anisotropy in quartz mica schist is an essential rock mechanics problem which needs to be seriously addressed during the design phase of Danba hydropower project.Firstly,a set of specially designed multi -angle UCTs was conducted as a baseline calibration,based on which three numerical simulation methods for anisotropy were demonstrated and discussed respectively,e.g.The discrete element method,synthetic rock mass method and joined -rockmass -constitutive -model -based continuum method.The result indicates that the deformation of the strength and failure model varies with the loading angle,and the rock proves its weakest property in the oblique direction.And the anisotropy of deformation and strength of the rock can be preferably expressed by the three method in numerical calculation,despite they may have their respectively advantages and disadvantages.Ultimately,the joined -rockmass -constitutive -model -based continuum method was adopted to perform an excavation simulation of the exploratory tunnel CPD -1.The simulated failure zone is highly ac-cord with tested sonic relaxation zone.Therefore the dominate effect of the schistosity plane on the failure mode and location is raveled.