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以鄂尔多斯梅林庙矿500~600 m处红砂岩为研究对象,分别对不同冻结温度(10℃,-5℃,-10℃,-15℃)、不同围压(0,4,8,12 MPa)条件下饱水红砂岩进行三轴压缩试验。试验结果表明:(1)温度在10℃~-15℃变化时,饱水红砂岩的三轴抗压强度随温度的降低而增大,呈指数关系;弹性模量随温度的降低而增大,呈线性关系;黏聚力c随温度降低而减小;内摩擦角φ随温度降低而增大;(2)围压在0~12 MPa变化时,饱水红砂岩三轴抗压强度随围压的增加而增大,呈线性关系,仍然满足Mohr准则;弹性模量、峰值轴向应变、径向应变随围压的增大而增大,塑性增强;(3)试验条件下,泊松比受围压影响较小,但受温度影响显著,试验时应妥善考虑温度对泊松比的影响;弹性模量E受温度影响巨大,受围压影响显著,温度是弹性模量的主要影响因素,围压为次要影响因素。相对于泊松比而言,弹性模量的取值更易于受外界环境影响。(4)饱水红砂岩试件的破坏形态受温度和围压影响显著,但两者的破坏机制不同。温度降低导致岩石颗粒引力降低,孔隙冰增大了孔隙的摩擦面积,进而增大摩擦力;围压增大,则是由于岩石内部形成微裂隙,使黏聚力下降,同时也使得围压在垂直破裂面上的分力增加,进而增大摩擦力。
Taking red sandstone at 500-600 m in Meilinmiao ore deposit of Erdos as research object, the effects of different freezing temperatures (10 ℃, -5 ℃, -10 ℃, -15 ℃), different confining pressures (0,4,8,12 MPa ) Under the conditions of saturated red sandstone triaxial compression test. The results show that: (1) When the temperature varies from 10 ℃ to -15 ℃, the triaxial compressive strength of saturated red sandstone increases exponentially with the decrease of temperature, and the elastic modulus increases with the decrease of temperature , While the cohesion c decreases with decreasing temperature. The internal friction angle φ increases with decreasing temperature. (3) When the confining pressure changes from 0 to 12 MPa, the triaxial compressive strength The confining pressure increases and increases linearly, and still meets the Mohr criterion; the elastic modulus, the peak axial strain and the radial strain increase with the increase of the confining pressure and the plasticity increases; (3) Under the experimental conditions, Matsubari is less affected by confining pressure, but it is significantly influenced by temperature. The influence of temperature on Poisson’s ratio should be considered carefully. Elastic modulus E is greatly influenced by temperature and temperature is the main factor of elastic modulus Influencing factors, confining pressure as the secondary influencing factors. Relative to the Poisson’s ratio, the elastic modulus is more easily influenced by the external environment. (4) The failure modes of saturated red sandstone samples are significantly affected by temperature and confining pressure, but the failure mechanisms of the two are different. The decrease of temperature leads to the decrease of the gravitational force of rock particles. The pore ice increases the frictional area of the pores and increases the frictional force. The increase of confining pressure is due to the formation of micro-cracks in the rock and the decrease of cohesion, The vertical component of the fracture surface increases, thereby increasing the friction.