冻土单轴抗压强度影响因素的试验研究

新疆地区是我国典型的咸寒区, 渠基土在冬季的冻结引起了输水渠道衬砌的破坏. 为了解冻结状态下渠基土的物理力学特性, 在常应变率条件下对新疆北疆季节性冻土区的含硫酸钠渠基土进行了多种条件下的单轴抗压强度试验. 结果表明: 单轴抗压强度随温度的降低线性增加; 单轴抗压强度随干密度的增加而增大, 二者之间具有较好的幂函数关系. 与氯化钠盐渍土不同, 硫酸盐渍土的单轴抗压强度随着硫酸钠含量的升高而增大, 并且呈现近似线性增加的特性.

Experimental study on the factors influencing the uniaxial compressive strength of frozen soil

The Xinjiang Uygur Autonomous Region is a typical salty cold region, where the conveyance channels are severely damaged by the frost heave and salt expansion of the channel bed soil. To study the soil properties and solve this problem, a series of uniaxial compressive strength tests at-5 ℃,-10 ℃,-15 ℃ and-20 ℃, with salt content of 0.2%, 1.6%, 3.0% and 4.4%, under the dry density of 1.89 g·cm^-3, 1.85 g·cm^-3, 1.80 g·cm^-3and 1.70 g·cm^-3, respectively, have been conducted. The test results show that the uniaxial compressive strength is sensitive to temperature; the uniaxial compressive strength increases with temperature decreasing at different salt contents and there is a power function relationship between the uniaxial compressive strength and dry density; moreover, uniaxial compressive strength of this saline soil with Na₂SO₄is different from that with NaCl. The experiment data at the four temperatures and the four dry densities indicate that the more the Na₂SO₄, the higher the strength.