膨润土防水毯搭接方式渗流特性试验研究

为了从渗流量和渗透稳定角度深入研究膨润土防水毯搭接处的防渗问题,开发了由压力控制系统和模型试验系统两部分组成的具有施加法向应力作用的接触面渗流试验装置,建立了真实模拟设计提出的防水毯铺设工序的渗流搭接物理试验方法,并通过不同工况下的膨润土防水毯搭接渗流试验,初步探讨了搭接处膨润土发挥防渗作用的最佳状态。结果表明:防水毯的搭接宽度宜大于30 cm;搭接处的膨润土添加量最好在4000~5000 g/m2之间选取;取防水毯规格型号为5000 g/m2能满足防渗体的要求;围压大小和加载路径对搭接处的渗透性影响均较大,若围压先增大然后再减小,搭接处仍能保持较为密实,其渗透性变化不大。

Experimental study on seepage properties of GCL with different overlap methods

For a thorough research on the GCL overlap anti-seepage problem in terms of seepage flux and seepage stability, an overlap seepage physical test method for the simulation of GCL installation process is established by developing an interface seepage experimental apparatus consisting of pressure control system and model test system under normal stress. The optimization of anti-seepage of the overlap bentonite is preliminarily discussed according to the tests under different conditions. The results show that the GCL overlap width should be more than 30 cm. The amount of bentonite added on the overlap should not be less than 4000 g/m², preferably between 4000~5000 g/m². GCL model specification 5000 g/m² is able to meet the requirements of impervious body. The magnitude of confining pressure and the load path both have great impact on the permeability of the overlap. The overlap remains dense and firm and its permeability changes a little if the confining pressure first increases and then decreases.