Experimental study on anisotropic layered sandstone under the thermal-mechanical action

Using MTS815 type programmable servo rigidity tester in high temperature sandstone plates on the conventional triaxial compression test, based on the test result analysis of the characteristics and deformation parameters and strength of the specimen failure mode as temperatures(20 ℃-150 ℃) and the angle of bedding (0°-90°), and discusses the layered sandstone anisotropic temperature effect. The results show that: (1) With the increase of angle, elastic modulus of rock shows the trend of decrease. Poisson's ratio, crack stress, stress and peak stress shows the trend of increase with the decrease of the first. (2) With the increase of temperature, the elastic modulus showed a trend of decrease after the first increase, Poisson's ratio shows the trend of increase with the decrease of the first. Temperature 20 ℃-120 ℃, crack expansion and stress, stress and peak stress overall weak growth trends, significantly reduced after the temperature over 120 ℃, the temperature between 120 ℃-150 ℃ a critical temperature, makes the mechanical properties of sandstone mutation. (3) The degree of anisotropy sandstone plates belongs to low anisotropy, the anisotropy of sandstone varies little with temperature from 20 ℃ to 120 ℃, and temperature 120 ℃-150 ℃, with the increase of temperature, improve the degree of anisotropy of sandstone. (4) The failure modes of bedded sandstone are affected by temperature and angle of the common. Rock damage with temperature rise by the shear failure makes the transition to tension damage. Angle of 30°, the sample mainly occurs shear damage along the bedding plane, and the strength of the rock sample minimum angle of 30°, indicating that the sandstone angle of 30° is mechanical characteristics, strength characteristics and failure mode of the most unfavourable angle. © 2019, Science Press. All right reserved.