【摘要】 岩盐的基本力学特性和破坏特征的实验结果表明,岩盐是一种“杨氏模量/强度(E/S)”比值极低的特殊软岩,其破坏遵循变形破坏准则。根据最大拉应变强度理论建立了岩盐水力压裂时计入铅直应力效应的破裂判据,并建议一般应采用单轴压缩实验来确定临界拉应变值。该判据与实验结果极为一致,适应于各种应力状态下任何具有较小E/S比值的软岩。更多还原

【Abstract】 Experimental results of the basic mechanical properties and failure mode performed on rock salt demonstrate that rock salt is a typical and peculiar soft rock , whose" Young’ s modulus/strength(E/S)"ratio is extremely small,and whose failure follows the deformation failure criterion. With these results,this paper develops a theoretic breakdown criterion of hydraulic fracturing in rock salt,which is based on the greatest tension strain failure theory and includes the vertical stress effects. It has been suggested that the critical tension strain should be determined from uniaxial compression tests. This theoretic criterion exceedingly agrees with experimental results and is applicable for every soft rock with small E/S ratio under various stresses.更多还原