The influence of low temperature on longitudinal wave velocity, uniaxial compression strength, tensile strength, peak strain, secant modulus, and acoustic emission characteristics of yellow sandstones was studied. The results show that the secant modulus increases with decreasing temperature when the axial strain is less than 0.6%, and a contrary influence performs for the subsequent stage due to the fracture of the pore ice. With the decrease in temperature, the uniaxial compression strength first increases and then remains at a relatively constant value of 34.44 MPa at about -40°C while the temperature ranges from -40°C to -70°C. The tensile strength shows an approximate linear increment as the temperature. The peak strain gradually increases with temperature in a three-stage piecewise linear form, and the increasing rate gradually decreases with the decreasing temperature. The phase transformation from liquid water at a temperature of 20°C to solid ice at a temperature of -3°C significantly increases the longitudinal wave velocity from 1.55 km/s to 3.36 km/s. When the temperature is lower than -10°C, the longitudinal wave velocity approximately increases linearly at a rate of with decreasing temperature.

中文翻译：

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冻结多孔砂岩单轴压缩力学行为

研究了低温对黄砂岩纵波速度、单轴抗压强度、抗拉强度、峰值应变、割线模量和声发射特性的影响。结果表明，当轴向应变小于0.6%时，割线模量随着温度的降低而增加，孔隙冰的破裂对后续阶段产生相反的影响。随着温度的降低，单轴压缩强度先增加，然后在-40°C左右保持在34.44 MPa的相对恒定值，而温度范围从-40°C到-70°C。拉伸强度随着温度显示近似线性增量。峰值应变以三级分段线性形式随温度逐渐增加，并且随着温度的降低，增加的速率逐渐减小。从 20°C 温度的液态水到 -3°C 温度的固态冰的相变使纵波速度从 1.55 km/s 显着增加到 3.36 km/s。当温度低于-10°C时，纵波速度近似线性增加 随着温度的降低。