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通过对陕西杨凌Q_3黄土进行不同初始含水量、不同低温温度及不同冻融循环次数条件下的静三轴剪切试验,揭示不同初始含水率、不同低温温度及不同冻融循环次数对黄土力学性质影响的过程与机理,基于极限平衡法建立冻融循环作用下强度参数的损伤模型。研究结果表明:黄土强度参数随冻融循环产生劣化,黄土的黏聚力c开始时冻融循环劣化效应强烈,在经过5~7次冻融循环后,黏聚力达到一个稳定值,当含水量很高时黏聚力下降不明显,内摩擦角φ随冻融循环次数无明显变化;建立的强度参数值随冻融循环次数增加的损伤模型能够很好地反映冻融循环作用下黄土抗剪强度的折减劣化规律,该损伤模型对冻融损伤作用下黄土地区的工程设计与施工具有指导和借鉴意义。
Through the static triaxial shear tests of Yangling Q3 loess with different initial water content, different cryogenic temperatures and different freeze-thaw cycles, the effects of different initial moisture contents, different cryogenic temperatures and different freeze-thaw cycles on the mechanical properties of loess The process and mechanism of the damage, the damage model of the strength parameter under the freeze-thaw cycle was established based on the limit equilibrium method. The results show that the strength parameters of loess are deteriorated with the freeze-thaw cycles. The cohesion of loess at the beginning of the freeze-thaw cycle is strongly deteriorated. After 5 to 7 freeze-thaw cycles, the cohesion reaches a steady value. When the amount of water is high, the cohesion decreases little, and the internal friction angle φ does not change obviously with the number of freeze-thaw cycles. The established damage model with the increase of the number of freeze-thaw cycles can well reflect the effects of the loess resistance Shear strength of the reduction and degradation of the law, the damage model of frozen and thawed loess area under the engineering design and construction with guidance and reference.