【摘要】 基于三剪统一强度准则研究了岩石裂纹压剪断裂问题,根据最小J₂准则、最大拉应力准则及最小能量密度因子理论确定的岩石起裂角,给出了相应的岩石裂纹压剪断裂判据。通过断裂判据,计算出不同岩石的纯Ⅱ型裂纹断裂韧度与纯Ⅰ型裂纹断裂韧度的比值,并与试验值及其他准则的断裂判据理论比值进行了对比,发现通过改变中间主应力效应系数b,该比值可更接近实际值。该比值在开裂角确定时,与泊松比ν、内摩擦角φ及三剪统一强度准则中的中间主应力效应系数b有关,结果表明该断裂判据有一定的合理性。更多还原

【Abstract】 The compression-shear fracture problem of rock was researched based on the triple-shear unified failure criterion.According to the initial crack angle given by the minimum J₂ criterion,the maximum tensive stress fracture criterion,and the minimum energy factor theory,the compression-shear fracture condition of rock was proposed.Through the fracture criterion,the ratio of the fracture toughness of the pure type Ⅱ crack to that of the pure type Ⅰ crack was calculated and compared with the test value and the theoretical ratio of the fracture criterion.And it was found that by changing the middle principal stress effect coefficient,the ratio can be closer to the actual value.When the initial angle of crack was determined,it was related to the middle principal stress effect coefficient in Poisson’s ratio,internal friction angle and the unified strength criterion of three shears.The results showed that the fracture criterion is reasonable.更多还原