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岩石作为矿物颗粒的集合体,其宏观力学特性主要影响因素为矿物的细观形态特征。基于颗粒流理论,建立了4种代表颗粒形状用于模拟石英砂岩的矿物颗粒,并采用球度指标对矿物颗粒形状进行参数量化。通过石英砂岩的室内三轴试验校准了颗粒流模型的细观参数,在此基础上进行四种矿物颗粒形状试样的岩石三轴力学模拟试验。研究结果表明:颗粒的球度越大,试样的启裂强度、损伤强度和峰值强度均越低。随着颗粒球度的增加,试样的弹模降低,泊松比增大。内摩擦角和黏聚力则随球度的增大而下降。根据岩样数值试验中的变形数据,研究了不同颗粒形状剪胀角随着塑性剪切应变的演化规律。
Rock as a collection of mineral particles, the main mechanical properties of macroscopic mechanical properties of the mesoscopic morphology characteristics. Based on the theory of particle flow, four kinds of mineral particles that represent the particle shape for simulating quartz sandstone are established, and the sphericity index is used to quantify the mineral particle shape. Based on the triaxial test of quartz sandstone, the mesoscopic parameters of the particle flow model were calibrated. Based on this, the triaxial mechanical simulation of rock specimens was carried out. The results show that the larger the sphericity of the particles, the lower the breaking strength, the damage strength and the peak intensity of the sample. As the particle sphericity increases, the elastic modulus of the specimen decreases and the Poisson’s ratio increases. The internal friction angle and cohesion decrease with the increase of the sphericity. According to the deformation data in the numerical test of rock samples, the evolution law of the dilatancy angle of various particle shapes with the plastic shear strain was studied.