含冰软弱面的冻结裂隙红砂岩的强度试验

Strength test on frozen cracked red sandstone combined with ice

为了研究冻结条件下西部地区裂隙岩体的力学性质,以西部中生代地层典型的红砂岩为试验对象,通过数码显微镜观察分析了红砂岩的颗粒、孔洞分布特征,并在-5^-15℃条件下,对无裂隙冻结红砂岩和裂隙倾角β为0°,15°,30°和45°的冻结裂隙红砂岩进行了单轴和三轴压缩试验。试验结果表明:冻结红砂岩和冻结裂隙红砂岩的强度都随围压的增加而线性增加。冻结裂隙红砂岩强度随着裂隙倾角的增加而非线性递减,在裂隙倾角大于30°后,强度降低的幅度不大。含冰软弱面的冻结裂隙红砂岩的强度和侧向变形主要受裂隙冰控制,因此工程中需要了解裂隙的角度分布特征。

In order to investigate the mechanical property of frozen rock mass in western area,the particle size distribution and pore distribution of typical red sandstone in western Mesozoic strata were analyzed with premier digital microscope. Uniaxial and triaxial compression test on frozen red sandstone and frozen cracked red sandstone with crack angle of 0°,15°,30°and 45° were conducted under temperature from- 5 ℃ to- 15 ℃. The experimental results indicate that the strength of cracked or no cracked red sandstone increased linearly with confinement. Strength of frozen cracked red sandstone decreased with crack angle nonlinearly,when the crack angle was larger than 30°,strength decrease extent was less. The strength and the lateral deformation of frozen cracked red sandstone were under the control of ice weak plane. The distribution characteristics of crack width and angle need to be investigated in engineering.