Particle Mechanics Modeling Of Thermal Effects On Shear Behavior Of Granitic Fracture Rocks In Beishan,Gansu Province

A better understanding of thermal-stress effects on the mechanical behavior of minerals and rocks is becoming critical when it comes to the issues associated with underground engineering and programs involved in geothermal systems,high-level radioactive waste depositing and geological carbon storage.Particle mechanics method,as a powerful tool,is used to simulate the process of thermally induced micro-cracks in granitic rocks.In this study,three group of heterogeneous joint specimens collected from Beishan,Gansu Province,are generated and treated as granitic rock sample consisting of four major minerals,then are subjected to heating–cooling cycles of increased holding temperatures ranging from 20 °C to400 °C.Crack number is coordinating with temperature incremental and has an effect on the strength of the specimen under the direct shear tests.Moreover,the distribution of micro-cracks resulting of thermal effect plays a role in the propagation of cracks in the asperities and increases fracture toughness of asperities,showing there is possibility that granitic rock is strengthen in loading process with pre-existed micro-cracks.Holding temperature and the components of the minerals may have the most significant contributions on thermally-treated joint specimen.