EXPERIMENTAL STUDY OF THERMOPHYSICO-MECHANICAL PROPERTY OF DRILLING SURROUNDING ROCK IN GRANITE UNDER HIGH TEMPERATURE AND HIGH PRESSURE
XI Baoping1，2，ZHAO Yangsheng1，2，3
(1. College of Mining Engineering，Taiyuan University of Technology，Taiyuan，Shanxi 030024，China； 2. Institute of Mining Technology，Taiyuan University of Technology，Taiyuan，Shanxi 030024，China； 3. College of Mining Engineering，China University of Mining and Technology，Xuzhou，Jiangsu 221008，China)
Abstract：Utilizing the 20 MN servo-controlled triaxial rock testing machine under high temperature and high pressure developed by the authors，the intensive experimental study of the thermo-elastic deformation of large size granite sample of f200 mm×400 mm with f40 mm borehole under triaxial hydrostatic pressure in depth of 6 000 m and temperatures within 600 ℃ is carried out. Based on the results of thermo-elastic deformation experiments under high temperature and pressure inversion to calculate the thermophysical and mechanical parameters，a careful analysis of the thermophysical and mechanical parameters of drilling surrounding rock in granite is carrial. The results show that：(1) The thermal deformation of the drilling surrounding rock in granite under high temperature and high pressure at different depths can be divided into three stages：low-temperature thermal deformation of a weak phase，the rapid growth stage heat distortion temperature and high-temperature thermal deformation of a smooth phase；and the depth (pressure) is significant impact on the thermal deformation of drilling surrounding rock in granite. (2) The failure mode of drilling surrounding rock in granite under high temperature and high pressure is of cutting damage，granite body in the experience of 500 ℃–600 ℃ high temperature continued to show a brittle emerged in characteristics. And rock mass destruction conditions are triaxial hydrostatic pressure in depth of about 6 000 m and temperature of 600 ℃. (3) The elastic modulus of drilling surrounding rock in granite under high temperature with a negative temperature decreases exponentially. (4) The Poisson's ratio of drilling surrounding rock in granite under high temperature with increasing temperature increases with the overall trend of its variation. (5) The thermal coefficients of expansion about surrounding rock of drilling at different hydrostatic pressures in depth and high temperature are different；the depth has a significant impact on the thermal coefficient of expansion. This experimental study can provide a theoretical basis and technical reserves for hot dry rock of deep drilling and maintenance of stability of drilling surrounding rock.
郤保平,赵阳升,. 高温高压下花岗岩中钻孔围岩的热物理及力学 特性试验研究[J]. 岩石力学与工程学报, 2010, 29(06): 1245-1253.
XI Baoping1，2，ZHAO Yangsheng1，2，3. EXPERIMENTAL STUDY OF THERMOPHYSICO-MECHANICAL PROPERTY OF DRILLING SURROUNDING ROCK IN GRANITE UNDER HIGH TEMPERATURE AND HIGH PRESSURE. , 2010, 29(06): 1245-1253.
