不同赋存深度岩石的动态断裂韧性与拉伸强度研究

按照国际岩石力学学会试验规范以及工程岩体试验方法标准(GB/T50266-99),对不同赋存深度的玄武岩试件分别进行动态断裂韧性测试和单轴拉伸强度测试,得到动态断裂韧性与拉伸强度之间可能存在一定的关系;并从岩石破坏的力学机制角度,分析动态断裂韧性与拉伸强度之间存在联系的根本原因:两者均是由于岩石内部微裂纹受到拉应力作用而引起微裂纹的扩展、互相贯通,从而导致岩石的破坏。根据动态断裂韧性与拉伸强度之间可能存在的关系,可以由拉伸强度的测试结果推测试件的动态断裂韧性值,将大大简化动态断裂韧性测试的繁琐性。

RESEARCH ON DYNAMIC FRACTURE TOUGHNESS AND TENSILE STRENGTH OF ROCK AT DIFFERENT DEPTHS

According to the standard test method suggested by ISRM and Standard for Test Method of Engineering Rock Mass(GB/T50266–99)，the dynamic fracture toughness and uniaxial tensile strength of the basalt specimens at different depths are measured. It is observed that there may be a certain relation between dynamic fracture toughness and tensile strength. From the point of view of rock failure mechanism，the essential reason for existing relation between dynamic fracture toughness and tensile strength is analyzed. Rock failure is due to the microcrack unstable propagation. The growth，propagation and coalescence of microcracks in rocks induced by tensile stresses lead to the failure of rock. It provides an easy method to estimate the dynamic fracture toughness by the tensile strength value according to the certain relation between dynamic fracture toughness and tensile strength. It will greatly simplify the dynamic fracture toughness test.