【摘要】 黏性土在水利工程建设中常被认为是不透水层或隔水层,其渗透性多为弱透水或微透水,若黏性土发育有较多管状孔隙,其土体结构将会发生变化,渗透性也会改变。含管状孔隙黏性土常发育在山前洪积扇的前缘。受目前钻孔内取土样设备所限,土样采取时对管状孔隙结构破坏严重,室内制环刀样时容易对管状孔隙造成破坏或堵塞,不能得到含管状孔隙黏性土真正的渗透系数。为正确认识含管状孔隙黏性土的渗透性,采取了多种室内和室外渗透试验手段,并经过反复对比分析,观察到其渗透性等级多为中等透水,明显大于一般意义上的黏性土,并且其渗透具有方向性,经抽水试验分析验证,在垂直方向的渗透性要远大于水平方向的渗透性。更多还原

【Abstract】 Cohesive soil is often considered to be impervious or a water-proof layer in the construction of water conservancy projects. Its permeability is mostly weak or slightly. Cohesive soil containing tubular pores develops at the leading edge of the piedmont alluvial fan. Due to the current equipment for taking soil samples, the structural damage of the tubular pores is serious when the soil samples are taken and the tubular pores are easily broken or blocked during the indoor ring-making process and the true permeability coefficient of the cohesive soil containing tubular pores cannot be obtained. If there are more tubular pores in the cohesive soil, the soil structure will be changed and the permeability will also be changed. In order to confirm the permeability of cohesive soil containing tubular pores, some indoor and outdoor permeability test methods were adopted. Through repeated comparison and analysis, it was observed that the permeability grade was mostly medium, which was obviously larger than that in the general sense. Its permeability had directionality. The results of pumping test show that the permeability in vertical direction is much greater than that in horizontal direction.更多还原