低温冻结作用下砂质泥岩基本力学特性试验研究

Experimental study on basic mechanical behaviors of sandy mudstone under low freezing temperature

以砂质泥岩为研究对象,对饱水状态岩石试件进行不同温度（-30~20℃）、不同围压（6,8,10 MPa）条件下的单轴压缩试验及三轴压缩试验,分析了低温对砂质泥岩基本力学参数的影响规律,探讨了抗压强度和残余强度随围压的变化。研究结果表明：低温（0℃以下）对砂质泥岩强度特性和变形特性均有较大的影响,其抗压强度、黏聚力、内摩擦角、残余强度和弹性模量随温度的降低均有所提高,残余强度呈衰减增长趋势,而最大轴向应变值随着温度的降低而不断减小。围压对砂质泥岩强度特性的影响非常明显,抗压强度、残余强度均随围压的增加呈线性增加。通过对大量的试验数据进行分析,得到一系列有意义的拟合曲线及关系表达式。

In order to get the basic mechanical properties of sandy mudstone for the investigation, water-saturation rock samples were tested by uniaxial and triaxial compressive tests under different temperatures （ -30-20 ℃ ）and different conditions of confining pressure （6,8,10 MPa）. The effect of low temperature on the basic mechanical parameters of sandy mudstone was analyzed, and compressive strength and residual strength were discussed along with the change ofthe confining pressure test. The results show as follows：low temperature （below 0 ℃ ） has great influence on strength properties and deformation characteristics of sandy mudstone, and compressive strength, cohesion, internal friction an- gle, residual strength and elastic modulus increase with the decrease of temperature;residual strength has an attenua-tion increasing trend, and the maximum axial strain decreases with the decrease of temperature. Confining pressure has great influence on strength characteristics of sandy mudstone, and compressive strength and residual strength increase linearly with the increase of confining pressure. By analyzing a lot of experimental data, getting a series of fitting curvesand their relational expressions.