岩石断裂韧度与抗压强度的相关规律

利用Instron 1342型电液伺服材料试验机,采用单轴压缩试验和双扭常位移松弛试验对大理岩、上盘二辉橄榄岩、下盘二辉橄榄岩、矿石、混合岩5组岩石的试件进行力学参数测试,获得相应的抗压强度、Ⅰ型断裂韧度等试验数据.以试验数据为依据,分析这5组岩石的Ⅰ型断裂韧度与抗压强度的关系.研究结果表明:随着抗压强度σ_c的增加,I型断裂韧度K_(Ⅰc)相应增大,且呈很好的线性关系,其关系式为:K_(Ⅰc)=0.026 5σ_c+0.001 4,其相关系数R~2为0.94.基于该关系式,可由易于测试的抗压强度估算Ⅰ型断裂韧度.

Interrelated law between mode-Ⅰ fracture toughness and compression strength of rock

The mechanics parameters of marble, upper lherzolite, down lherzolite, granite and ore were tested by uniaxial compression testing and relaxation method of double torsion constant displacement load using Instronl342 type electro hydraulic servo test machine. Compression strength and the mode-Ⅰ fracture toughness K_(IC) were obtained. Their relationships were studied based on the testing data. The results show that mode-Ⅰ fracture toughness K_(IC) increases with the increase of compression strength σ_c, and the curve of mode-Ⅰ fracture toughness K_(IC) and compression strength σ_c is in accordance with linear rule, the expression is: K_(IC) =0.026 5σ_c+0.001 4, and the coefficient of determination R~2 is 0.94. The expression may provide a helpful method for estimating the fracture toughness through the compression strength which can be measured easily.