关键词: 单侧干湿循环, 核磁共振, 孔隙结构, 力学特性, 能量演化

Abstract: To study the effect of the unilateral wet and dry cycle on the sandstone with different particle sizes, the red sandstone and the gray sandstone samples were used in the study. The nuclear magnetic resonance method was used to test the saturated sandstone under different wet-dry cycle times and the water-soaked sandstone samples at different time periods to study the pore structure characteristics and the permeability. Through the uniaxial compression tests, the mechanical properties and the energy evolution of the two sandstone samples are discussed. The results show that with the increase of the dry and wet cycles, the gray sandstone samples under different time of water immersion reaches saturation first than the red sandstone samples and have a better permeability. When the dry-wet cycle reaches 60 times, the results of the NMR imaging show that both sandstone samples have directional damage accumulation, and the damage accumulation degree of the gray sandstone samples is greater than that of the red sandstone samples. In the uniaxial compression tests, the uniaxial compressive strength and the total deterioration degree of the elastic modulus of the gray sandstone samples are larger than that of the red sandstone samples.

Key words: Unilateral Wet and Dry Cycle, Nuclear Magnetic Resonance, Pore Structure, Mechanical Properties, Energy Evolution