聚丙烯纤维加筋黄土抗渗性能试验研究

    EXPERIMENTAL STUDY ON ANTI-SEEPAGE OF POLYPROPYLENE FIBER-REINFORCED LOESS

    • 摘要: 纤维导流效应会加速水分入渗,造成土体抗渗性能削弱,不利于集中降雨条件下的黄土边坡长效防护。基于室内试验,研究了纤维掺量、纤维长度、干密度对纤维黄土渗透系数的影响规律,揭示了不同压实条件下纤维土柱的垂直入渗规律与模型,并结合试验获得的纤维黄土处理厚度,开展现场水分监测试验,探讨了纤维防护边坡浅层土壤的水分变异特征与抗渗效果。结果表明:纤维黄土的渗透系数随纤维掺量减小、长度增长和干密度增大而减小,变化敏感性由强到弱依次为干密度、纤维掺量、纤维长度,其中以干密度作为主要控制因素,能够对纤维导流效应起到抑制作用;压实充分是确保纤维黄土维持良好抗渗性能的必要条件,相比压实度为80%的纤维土柱,压实度为90%的纤维土柱稳定入渗时间增加36.36%,初始入渗速率,稳定入渗速率减小50.00%,83.33%,水分初次响应时间推迟约15% ~50%,通过构建入渗历时与入渗速率、湿润锋推进深度之间的函数关系,预估了积水状态纤维黄土的入渗特征和现场处理厚度;在雨季长达4个月的自然气候干扰下,纤维黄土表现出优良的现场抗渗防护效果,当水土质量比为0.37,边坡平台,坡面的纤维黄土处理厚度为15 cm,10 cm时,边坡内部各测点体积含水率均保持稳定,变异系数为0.78% ~1.36%,仅为无防护边坡的1/9。

       

      Abstract: The fiber infiltration effect will accelerate the water infiltration and cause the weakening of soil impermeability,which is not conducive to the long-term protection of loess slopes under concentrated rainfall conditions. To comprehensively evaluate the influence law of fiber loess,ber length,and dry density on the permeability coefficient was studied,the vertical infiltration law and model of fiber soil column under different compaction conditions were revealed,and the moisture monitoring test was carried out in the field combined with the fiber loess treatment thickness obtained from the test to explore the moisture variation characteristics and impermeability effect of the shallow soil of fiber protection slope. The results show that the infiltration coefficient of fiber loess decreases with decreasing fiber admixture,increasing length,and dry density,and the sensitivity of variation is from strong to weak in order of dry density,fiber admixture,and fiber length,among which dry density as the main controlling factor can play a suppressive role in fiber infiltration effect; adequate compaction is a necessary condition to ensure that fiber loess maintains good infiltration resistance. Compared with the fiber soil column with 80% compaction,the fiber soil column with 90% compaction has 36.36% more stable infiltration time,50.00% less initial infiltration rate,83.33% less stable infiltration rate,and about 15% ~50% more delayed initial moisture response time. When the water-soil mass ratio is 0.37,the slope platform and the thickness of fiber loess treatment on the slope surface is 15 and 10 cm,the volumetric water content of each measurement point inside the slope remains stable,and the coefficient of variation is 0.78% ~1.36%,which is only 1/9 of that of the unprotected slope.

       

    /

    返回文章
    返回