论文部分内容阅读
为了揭示短时冻土区冻融作用对残积土力学性质的损伤规律,对经历不同冻融条件的压实成型重塑三轴试样进行了不固结不排水的三轴剪切试验。试验结果表明:经历多次冻融循环作用后,残积土试样的应力-应变关系呈软化趋势,且在经历5次冻融循环作用后趋向于稳定状态;试样经历冻融作用后,弹性模量、黏聚力及内摩擦角均发生损伤且损伤幅度均随着冷端温度的升高、含水率的增大、冻融循环次数的增加而增大;土体黏聚力损伤程度最大,弹性模量其次,内摩擦角损伤程度最小;建立的考虑冷端温度、含水率及冻融循环次数影响的弹性模量、黏聚力及内摩擦角非线性损伤模型与试验数据结果吻合良好。
In order to reveal the law of damage to the mechanical properties of soil by the freezing and thawing of short-term permafrost regions, a triaxial shear test of unconsolidated and undrained soil was carried out on compacted and remolded triaxial specimens under different freezing and thawing conditions. The experimental results show that after repeated freeze-thaw cycles, the stress-strain relationship of residual soil samples shows a tendency of softening, and tends to be stable after 5 cycles of freeze-thaw cycles. After the sample undergoes freeze-thaw cycles, the elasticity Both the modulus, cohesion and internal friction angle were damaged and the damage amplitude increased with the increase of the temperature of the cold junction, the increase of water content and the increase of the number of freeze-thaw cycles. The cohesion damage of soil was the largest , Elastic modulus secondly, the degree of damage of internal friction angle is the smallest. The established nonlinear damage model of elastic modulus, cohesion and internal friction angle, which takes the influence of cold end temperature, moisture content and freeze-thaw cycles into account, is in good agreement with the experimental data .