Experimental study on thermal and mechanical characteristics of rock at low temperature

With increasing demand for LPG and LNG, more storage facilities are required in Korea. Due to the recent safety concerns and land shortage, storage facilities tend to be located in underground. For the construction of underground storage facilities for low temperature materials, mechanical and thermal properties of rock mass should be understood. In this study, laboratory experiments for the measurement of the mechanical properties such as UCS(Uniaxial compressive strength), tensile strength, fracture toughness etc. and thermal properties such as specific heat, thermal conductivity, and thermal expansion coefficient of rocks were performed in the temperature range of —160° to 40°. Experiment results show that UCS, tensile strength, fracture toughness increased with decreasing temperature, but Poisson’s ratio, specific heat and the thermal expansion coefficient decreased with decreasing temperature. Elastic modulus and thermal conductivity changed little with decreasing temperature. These changes showed more clear tendency in wet specimens than dry ones. The results of this study can be utilized for the evaluation of thermal propagation in rock mass and the thermo-mechanical stability of underground facilities at low temperatures.