摘要
为阐明冻融作用对多年冻土区路堑边坡稳定性的影响,首先建立粉质黏土黏聚力、内摩擦角与冻融次数之间的定量关系,其次探索冻融作用对粉质黏土抗剪强度的影响机制。最后,建立考虑冻融界面强度参数变化的边坡安全运营预测模型。研究发现:随着冻融次数的增加,粉质黏土的抗剪强度、黏聚力和内摩擦角均呈现下降趋势,黏聚力对冻融作用相对更敏感。冻融15次后,边坡安全系数降幅达47%。当边坡冻融影响深度从2.70 m增加至3.20 m时,边坡安全系数降低12%。基于室内、外冻融环境转换关系,将室内冻融试验数据直接应用于现场冻融条件下的边坡安全运营年限预测,为边坡稳定性定量化预测提供参考。
With the continuous development of the central and western regions,a number of high-grade highways will be built in the clod regions.However,the slope disasters caused by freeze-thaw cycles gradually increased.Focusing on the slope disaster in the cold region,the quantitative relationship between the cohesion,internal friction angle of silty clay,and the number of freeze-thaw was established to explore the influence of freeze-thaw action on the shear strength.Based on the experimental results,the limit equilibrium method was used to analyze the service life of the cutting slope with the consideration of variation of the parameters in the freezing-thawing interface.Results indicate that with the increase number of freeze-thaw cycles,all the shear strength,cohesion force,and internal friction angle of silty clay firstly decrease rapidly and then tend to a stable value.Cohesion force is more sensitive to freeze-thaw cycles,and it has a large contribution to the change of shear strength.After 15 times of freeze-thaw cycles,the safety factor of the slope decreases about 47%.When the freeze-thaw depth increases from 2.70 m to 3.20 m,the safety factor decreases 12%.Based on the conversion relationship between indoor and outdoor freezing-thawing environments,the indoor freezing-thawing test data can directly apply to predict the service time of slope under the field freezing-thawing conditions.The results can provide a reference for predicting stability and designing slope.
作者
张永顺
常明军
科文萍
明锋
ZHANG Yongshun;CHANG Mingjun;KE Wenping;MING Feng(Administrative Law Enforcement Supervision Bureau of Haibei Tibetan Autonomous Prefecture,Haibei,Qinghai 812200,China;Transportation Integrated Service Center of Haibei Tibetan Autonomous Prefecture,Haibei,Qinghai 812200,China;State Key Laboratory of Frozen Soil Engineering,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou,Gansu 730000,China)
出处
《水利与建筑工程学报》
2022年第3期89-94,共6页
Journal of Water Resources and Architectural Engineering
基金
国家自然科学基金(41701060)。
关键词
冻融循环
多年冻土区
路堑边坡
安全系数
freeze-thaw cycles
permafrost region
cutting slope
safety factor
