辉长岩微观破坏特征与破裂机制研究

Study on Microscopic Failure Characteristics and Failure Mechanism Ofgabbro

本文以粗粒辉长岩为研究对象,对其在单轴、常规三轴、三轴循环荷载试验下的破坏断口进行扫描电镜(SEM)试验,分析了岩石在不同应力状态下微观破坏形貌、破坏形式及破裂机制。试验结果表明在单轴、常规三轴情况下辉长岩微观破坏主要以穿晶断裂和沿晶面擦花的拉、剪破裂并存微观破裂机制;三轴循环荷载情况下微观破坏形貌以平坦面花样和长形微坑花样为主,为沿晶面擦花的剪断微观破坏机制。通过分析岩石微观破裂与宏观断裂之间的联系,证明了不同应力状态下微观破裂形式与宏观断裂形式具有很好的对应关系。该结论为岩石微观破裂机制与宏观断裂特征之间的联系研究提供了可靠的试验依据,具有一定的理论价值。

The coarse -grained gabbro as the research object, the uniaxial, conventional triaxial, Triaxial Cyclic Loading Test of fracture in the scanning electron nficroscope （SEM） test, analyzes the rock in different force state of the micro fracture morphology, failure mode and failure mechanisnL Test results show that the uniaxial, conventional triaxial micro gabbro damage mainly to transgranular fracture and intergranular surface rub flower pull, shear fracture coexist micro fracture mechanism; triaxial cyclic loading under microscopic damage morphology with flat surface pattern and elongated micro pit patterns mainly, along the crystal face rub flower shear micro fracture mechanisms. Through the analysis of the relation between rock micro fracture and macro fracture, it is proved that the form of micro fracture and macro fracture have good corresponding relationship under different stress states. The conclusion provides a reliable experimental basis for the relationship between the micro fracture mechanism of rock , and it has a certain theoretical value.