单向正融粉制黏土路基的静力学特性及显著性分析

Static Characteristics and Significance Analysis of One-way Melting Clay Roadbed

由于正融土体相较全融或全冻土体具有不稳定性,对路基土体会产生更大破坏,为了探究单向正融粉制黏土路基的静力学特性,通过改装动静三轴试验机,对不同围压、冻前含水率、顶端冻结负温、顶端融化温度进行了静三轴剪切试验,研究应力-应变曲线和静强度的变化规律,并且基于显著性分析对静强度进行探究。试验结果表明:随着围压和含水率的增加,应力-应变曲线逐渐由弹性-应变软化型变为弹性-应变硬化型;正融土静强度随顶端冻结负温的降低和融化温度的降低而升高,冻结负温比融化温度对正融土强度贡献更大;认为存在临界含水率,小于该含水率,静强度随含水率的增长而增大,大于该含水率则随含水率的增长而减小。通过显著性分析发现,围压对静强度影响最为显著,冻前含水率次之;同时,冻结和融化温度的交互作用也有较为显著的影响。

The melting soil is more stable than the fully-meltingor fully-freezing soil,which has more damage to the subgrade soil.In order to explore the static characteristics of a one-way positively melted clay roadbed,the modified dynamic and static triaxial testing machine was used to study the static characteristics of one-way positively melted clay roadbed.Static triaxial shear test was carried out on different confining pressures,pre-freeze moisture content,top freezing negative temperature and top melting temperature.The axial shear test studiedthe variation of the stress-strain curve and the static strength and exploredthe static strength based on the significance analysis.The test results show that with the increase of confining pressure and water content,the stress-strain curve gradually changes from elastic-strain softening to elastic-strain hardening.The static strength of positive melting is negative with the top freezing.The static strength of positive soil increases with the decrease of the freezing temperature and the melting temperature.Freezing negative temperature ratio melting temperature contributes more to positive melting strength.It is considered that there is a critical moisture content,which is smaller than the water content,the static strength increases with the water content increases,and the water content decreases with the water content increases.By significant analysis,it is found that confining pressure has the most significant effect on static strength,followed by the water content before freezing.At the same time,the interaction of the negative temperature and the melting temperature has an influence on the melting soil.