干湿循环作用下压实黄土湿陷特性试验研究

发布时间：2018-06-05 02:44

本文选题：黄土路基 + 压实黄土　；参考：《冰川冻土》2016年02期

【摘要】：压实黄土作为重要的填筑材料,广泛应用于我国西北、华北公路、铁路、机场等基础设施建设中.由于降雨及蒸发的周期性变化,黄土路基及基础经历着强烈的干湿交替作用.基于此,开展压实黄土风干干燥-滴水增湿条件下的干湿循环试验,利用双线法测试最佳含水量条件下不同初始压实度的黄土土样干湿循环前后的湿陷系数.结果表明:没有经历干湿交替作用的土样,湿陷系数随着压实度的增大而快速减小,当压实度达到90%,提高压实度对于黄土湿陷变形特征的影响较小;5次干湿循环作用后,不同压实度下的试样的湿陷系数均明显增大,且压实度越大,干湿作用对其湿陷变形的影响越显著;压实度K=95%试样在经历5次干湿循环作用后土样上部出现肉眼可见的细微孔隙,体积膨胀,有可溶盐析出,湿陷系数达到0.017,土样出现二次湿陷.
[Abstract]:As an important filling material, compacted loess is widely used in the infrastructure construction of Northwest China, North China Highway, Railway, Airport and so on. Because of the periodic changes of rainfall and evaporation, loess subgrade and foundation undergo strong dry and wet alternations. Based on this, the dry and wet cycle test of compacted loess under the condition of air-drying and dripping humidification was carried out, and the coefficient of collapsibility of loess soil samples with different initial compaction degrees before and after the drying and wet cycle under the optimum water content was measured by two-line method. The results show that the coefficient of collapsibility decreases rapidly with the increase of compaction degree, and when the compaction degree reaches 90, the effect of increasing compaction degree on the deformation characteristics of loess collapsing is less than that of dry and wet cycle. The collapsibility coefficient of the samples with different compaction increased obviously, and the greater the compaction degree, the more significant the effect of dry-wet action on the collapsing deformation. After five dry and wet cycles, the compaction degree of K _ (95)% of the sample showed tiny pores visible to the naked eye, volume expansion, soluble salting out, and the coefficient of collapsibility reached 0.017, and the soil sample had secondary collapsibility in the upper part of the soil sample.
【作者单位】：中国科学院寒区旱区环境与工程研究所冻土工程国家重点实验室;中国科学院大学;
【基金】：甘肃省科技重大专项计划项目(143GKDA007) 中国科学院西部之光重点项目;中国科学院寒区旱区环境与工程研究所STS项目(HHS-TSS-STS-1502)资助
【分类号】：TU475.3

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