膨润土防水毯破损条件下渗流特性试验研究

为了从渗流量和渗透稳定角度深入研究膨润土防水毯破损处的防渗问题，开发了由压力控制系统和模型试验系统两部分组成的渗流试验装置，建立了针对坝体防渗工程中的防水毯破损情况的渗流物理试验方法，并通过膨润土防水毯不同破损工况下的渗流试验，初步探讨了影响破损防水毯与坝身土体联合抗渗的因素。结果表明，对破损防水毯和土体的综合渗透系数的影响，孔洞大小比破损率要敏感；对于孔洞修复能力，主要的敏感的因素包括孔洞直径D及防水毯规格（材料本身性能）。在工程中要做好以下两点：（1）工程中刺破孔洞直径D小于0.5 cm，超过0.5 cm的孔洞应当做修补；（2）局部刺破率不宜大于0.5%，尽量保证防水毯接触面的平整。

An experimental study of seepage properties of geosynthetic clay liner with defects

For thorough research of the anti-seepage problem in terms of seepage flux and seepage stability due to the geosynthetic clay liner(GCL) defects, the seepage physical test method for the simulation of GCL with defects in dam anti-seepage hydraulic projects is established by means of developing the seepage experimental apparatus consisting of pressure control system and model test system. Factors which affect the joint impermeability of dam soil and GCL with defects are preliminarily discussed according to the seepage test of GCL with different defect conditions. The results show that the hole-defect’s size can be more sensitive to the impact of overall permeability of GCL with defects and soil than the defect rate. The main sensitive factors for defect’s healing capacity include hole-defect’s diameter and GCL specifications (material’s own performance). Therefore, two following points should be considered in the projects: (1) the hole-defect’s diameter should be less than 0.5 cm in the projects, the ones larger should be repaired; (2) make sure the GCL interface is smooth and flat in case that the local defect rate becomes more than 0.5%.