土工布对砂质土渗透特性影响规律的试验研究

设计了由马氏瓶和渗透仪组成的常水头渗透试验系统，展开了不设置土工布与设置土工布的对照试验，分别研究了土工布放置位置和层数对土体渗透性能的影响规律；土工布上部荷载对土工布自身渗透系数的影响．试验结果表明:土工布可以有效减小土体的渗透系数，增大其临界渗透破坏水头高度，从而提升土体的渗透稳定性．但土工布上部荷载的增加，会导致土工布自身渗透系数的变大．通过对试验数据的处理，发现渗透系数随着土工布位置的增高与土工布层数的增多而减小，临界渗透破坏水头高度随着土工布层数的增多而增大；在设置单层土工布的情况下，土工布放置于土体中间位置处时，临界渗透破坏水头高度达到最大，土体的渗流稳定性最好．使用本文所推导的公式，可以较好地计算土体内土工布设置的埋深与土体渗透系数的对应关系． 

Geotextiles impact on sandy soil permeability

A permeation test system of constant water head composed of Mariotte flash and permeation instrument was designed to study effect of geotextile placement position and layer number on soil permeability, and upper load influence on permeability coefficient of geotextiles．Geotextile was found to reduce effectively permeability coefficient of soil but increase height of critical seepage failure water head, thus improving permeability stability of soil．However, increase in upper load of geotextile was found to increase permeability coefficient of geotextile itself．Permeability coefficient was found to decrease with enhanced position of geotextile and increased layer numbers．Seepage failure critical water head height increased with increasing geotextile layers．For monolayer geotextile, when geotextile was placed in middle position of soil, seepage failure critical water head height reached a maximum, seepage stability of soil was the best．With the formula derived in this work, a relationship between permeability coefficient of soil and buried depth of geotextile in soil can be calculated．