Rock mass deformation failure and its mechanical characteristics in actual environment were basic research subjects in the current research field of rocks in cold regions. Mechanical characteristics of mode-I sandstone were investigated and analyzed under freeze thawing cycle, failure properties, and modes of the rock-like cracked mortar sample were measured and analyzed. Meanwhile, the finite element analysis of stress field of cracked sample was analyzed and calculated by means of the finite element program ANSYS. The experimental results showed that deterioration damage of mechanical parameters grew gradually worse as increasing of freeze thawing cycle. Compared with sound sandstone, fracture toughness K_IC, tensile strength, and compressive strength for sandstone sample after 100 freeze thawing cycle increased by 44.55%, 42.61%, and 40.41%, respectively. And peak strength and elastic modulus of the cracked mortar sample decreased initially and then increased as increasing of crack angle of inclinations. A certain difference occurred in deterioration damage of mechanical parameters of cracked mortar sample with crack angle of inclination. Deterioration damage of mechanical parameters of cracked mortar sample with the 45° crack angle of inclination had the lowest value, and highest values of the cracked mortar sample with the 90° or 0° crack angle of inclinations. In addition, original damage inside rocks had obvious influence on theirs damage deterioration. Failure mode of cracked mortar sample at the different crack angle of inclinations was different, but the effect of freeze thawing cycle on failure modes of cracked sample was not obvious.

实际环境下岩体变形破坏及其力学特性是当前寒区岩石研究领域的基础研究课题。对I型砂岩在冻融循环下的力学特性进行了研究和分析，对岩样开裂砂浆样品的破坏特性和模态进行了测量和分析。同时，利用有限元程序ANSYS，对裂纹试样的应力场进行了有限元分析和计算。实验结果表明，随着冻融循环次数的增加，力学参数的劣化损伤逐渐加重。与完好砂岩相比，断裂韧性K _IC100 次冻融循环后，砂岩样品的抗拉强度和抗压强度分别提高了 44.55%、42.61% 和 40.41%。开裂砂浆试样的峰值强度和弹性模量随着裂纹倾角的增大先减小后增大。裂纹砂浆试样力学参数随裂纹倾角的劣化损伤存在一定差异。45°裂纹倾角裂纹砂浆试样力学参数劣化损伤值最低，90°或0°裂纹倾角裂纹砂浆试样力学参数劣化损伤值最高。此外，岩石内部的原始损伤对其损伤恶化也有明显的影响。