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通过花岗岩的单轴试验、颗粒流程序和编制的fish语言程序获得了细观力学参数,并进行了不同围压下的花岗岩脆性破坏和延性破坏强度试验,分析了4种强度准则对脆延破坏强度的拟合与预测效果,得到如下结论:随着围压增加,屈服阶段增长,峰值强度提高,峰后软化效应减小,花岗岩由脆性破坏逐渐转变为延性破坏,脆延破坏分界围压为100 MPa;对花岗岩脆延破坏强度的整体拟合和预测精度,Mohr-Coulomb准则对脆性破坏强度的拟合误差最大且高估了延性破坏强度,指数强度准则拟合误差居中而低估了延性破坏强度,Hoek-Brown准则拟合精度也居中而预测结果与延性破坏强度相接近,Bieniawski准则拟合误差最小且对延性破坏强度的预测最优;花岗岩的围压影响系数随围压增加呈负指数关系减小,围压影响系数趋于定值的转折围压与花岗岩脆延破坏转化分界点对应围压基本一致,表明花岗岩脆性破坏阶段强度提高受围压影响显著,延性破坏阶段强度的单位围压提高率为定值。
Through the granite uniaxial test, the particle flow program and the prepared fish language program to obtain the mesomechanical parameters, and under different confining pressure granite brittle failure and ductile failure strength test, analysis of four kinds of strength criterion brittle failure damage With the increase of confining pressure, the yield stage increases, the peak strength increases, the post-peak softening effect decreases, and the granite gradually changes from brittle failure to ductile failure. The confining pressure of brittle failure is 100 MPa. The overall fitting and prediction accuracy of brittle failure strength of granite is the highest. The fitting error of Mohr-Coulomb criterion to brittle failure strength is the highest and the ductile failure strength is overestimated. The fitting error of index strength criterion is middle and the ductile failure is underestimated The Hoek-Brown criterion fitting accuracy is also approximate and the predicted result is close to the ductile failure strength. The Bieniawski criterion has the lowest fitting error and the best prediction of the ductile failure strength. The confining pressure influence coefficient of granite shows a negative exponent The relationship between the confining pressure and the confining pressure of the granite crushing and transforming demarcation point is basically the same, The increase of the strength of the granites in the brittle failure stage is significantly affected by the confining pressure. The unit confining pressure increase rate of the ductile failure stage is a fixed value.