Experimental study on mechanical properties of granite taken from Gonghe basin，Qinghai province after high temperature thermal damage#br#
XI Baoping1，2，WU Yangchun1，WANG Shuai1，XIONG Guiming1，ZHAO Yangsheng1，2#br#
(1. College of Mining Engineering，Taiyuan University of Technology，Taiyuan，Shanxi 030024，China；2. Key Laboratory of Insitu Property Improving Mining of Ministry of Education，Taiyuan University of Technology，Taiyuan，Shanxi 030024，China)
Abstract：The research on the mechanical properties of granite after high temperature thermal damage is of great significance for the successful implementation of dry hot rock geothermal demonstration project in Gonghe basin，Qinghai province，and it can provide mechanical parameters related to thermal damage of rock for the drilling project，artificial reservoir design and construction. Using macroscopic mechanical test method combined with the microscopic CT scanning，compressive strength，shear strength and tensile strength of granite from Gonghe basin，Qinghai province after high temperature thermal damage are studied，and the influence of natural cooling on crack formation of high temperature granite samples is also investigated. Through fitting the test data，empirical formulas of the compressive strength，elastic modulus，tensile strength，cohesion，internal friction angle with temperature are obtained，and a shear failure strength criterion of granite under thermo-mechanical coupling is established. The influence of the temperature on brittle-ductile transition of granite is discussed，and it is found that，at the temperature of 500 ℃ to 600 ℃，the ductility plays a dominant role. The cooling rate is closely related to the density of thermal fracture of granite. For the first 400 s of the natural cooling process of granite in the air，the cooling rate is the highest and the temperature gradient is the largest. Especially for the first 150s，the thermal crack is most severe. The research results can provide theoretical basis and technical support for the development and utilization of dry hot rock in China，and also enrich and develop the theory of high temperature rock mechanics.
郤保平1，2，吴阳春1，王 帅1，熊贵明1，赵阳升1，2. 青海共和盆地花岗岩高温热损伤力学特性试验研究[J]. 岩石力学与工程学报, 2020, 39(1): 69-83.
XI Baoping1，2，WU Yangchun1，WANG Shuai1，XIONG Guiming1，ZHAO Yangsheng1，2. Experimental study on mechanical properties of granite taken from Gonghe basin，Qinghai province after high temperature thermal damage#br#. , 2020, 39(1): 69-83.
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2020, Vol. 39 
