季冻区公路路基细粒土冻胀性分类研究

Research on Frost Heaving Classification of Fine-grain Soil of Highway Subgrade in Seasonally Frozen Ground Region

对4种不同塑性细粒土扰动样进行了室内闭式冻胀模拟试验,简述了土的含水量和塑性对冻胀性的影响,即各种细粒土的冻胀性都随着含水量增大而增强;在含水量相同时,土的冻胀性随着塑性增强和颗粒变细而减弱。应用数理统计方法分别得出了各种黏性土和粉土的冻胀率关于超塑含水量的经验公式,并经综合分析建立了细粒土的冻胀率关于超塑含水量的经验公式。在此基础上,对黏性土、粉土及细粒土进行冻胀性分类研究,并将研究结果与现行规范进行比较,给出合理建议。此外,还取原状样进行了室内冻胀试验并对原状样和扰动样冻胀性试验结果的相容性进行了分析,指出用扰动样模拟试验结果对细粒土进行冻胀性分类研究,是可靠和可行的。

According to the results of closed simulated frost heaving susceptibility experiments with four different plasticity fine-grained soil, the influences of soil water contents and plasticity on frost heaving suseeptibility is discussed. Frost heaving susceptibility will intensify when water content increases; when water content fixes, frost heaving susceptibility will weaken with plasticity intensifying. Using mathematical statistics, η-（ w - wp ）empirical equation of all kinds of clay silt is obtained, η-（ w - wp ）empirical equation of fine grained soil is established through analyzing synthetically. Research on frost heaving classification of clay, silt and fine-grained soil are conducted and the result are compared with curium standard. Frost heaving susceptibihty experiments of undisturbed sample are carried out and the consistency of test result of original sample and disturbed sample is analysed. It is found that it is feasible and credible to use undisturbed sample simulating test result for research on frost heaving classification of fine-grained soil.