论文部分内容阅读
为研究冻融循环次数和含水率对尾细砂力学性质的影响,利用GDH-2005B型高低温试验箱对尾矿砂试样进行冻融循环,并通过FST-200型应变控制式三轴剪力仪开展五种冻融循环次数(1次、3次、5次、7次、9次)和五种含水率(11%、13%、15%、17%、19%)尾矿砂试样常规三轴试验。研究表明:(1)相同含水率时,随着冻融循环次数的增大,变形模量逐渐减小,内聚力和内摩擦角均呈现降低的趋势;经历9次冻融循环后,内聚力降低至17.4kPa,内摩擦角降为14.82°。(2)相同冻融循环次数条件下,随着含水率的增大,尾矿砂的峰值应力降低,对应峰值应变增大;围压100kPa时,含水率19%的尾矿砂在经历9次冻融循环后应变为18.21%,应力为139.37kPa;各冻融循环次数下的尾矿砂抗压强度均呈现下降的趋势,内聚力和内摩擦角均随着含水率的增大而减小。研究成果可为尾矿砂物理力学性质理论的丰富以及尾矿砂相关工程的安全运营提供参考。
In order to study the effect of freeze-thaw cycles and moisture content on the mechanical properties of tailing sand, tailings samples were subjected to freeze-thaw cycles by using GDH-2005B high and low temperature test chamber. Through FST-200 strain controlled triaxial shear Tailings of five kinds of freeze-thaw cycles (1st, 3rd, 5th, 7th, 9th) and five kinds of moisture content (11%, 13%, 15%, 17%, 19% Triaxial test. The results show that: (1) With the same moisture content, the deformation modulus decreases with the increase of the number of freeze-thaw cycles, and the cohesion and internal friction angle decrease. After 9 freeze-thaw cycles, the cohesion decreases to 17.4kPa, the internal friction angle dropped to 14.82 °. (2) With the same number of freeze-thaw cycles, the peak stress of tailing sand decreases and the corresponding peak strain increases with the increase of water content. When the confining pressure is 100 kPa, the tailings with 19% moisture content undergoes 9 freeze-thaw cycles The strain after cycling is 18.21% and the stress is 139.37 kPa. The compressive strength of tailing sand decreases with the number of freeze-thaw cycles. The cohesion and internal friction angle decrease with the increase of water content. The research results can provide reference for enriching theory of tailings sand physical and mechanical properties and safe operation of tailings-related engineering.