泥皮存在时防渗墙与复合土工膜联接型式模型试验

防渗墙与复合土工膜联合作为防渗体系已广泛用于围堰工程，但变形不协调易导致联接部位处土工膜的破坏。通过某围堰工程复合土工膜与防渗墙联接部位离心模型试验，模拟防渗墙泥皮及其厚度、堰体填料的沉降变形等，研究不同联接方式时复合土工膜应变的变化规律。试验结果表明：当联接部位处土工膜水平铺设时，土工膜紧靠防渗墙的部位尤其是泥皮范围以内将产生较大应变，当防渗墙与周围堰体的差异变形达到一定量时，土工膜产生拉裂破坏；当土工膜先竖向抬高一段距离后再水平铺设，水平铺设段的土工膜应变明显减小，且随着与防渗墙的距离越远，土工膜应变越小。防渗墙泥皮的存在可有效缓解土工膜局部受力。

Experiment on connecting form between cutoff wall and composite geomembrane of cofferdam with existing wall mud

The combination of cutoff wall and composite geomembrane is usually used as the imperious system recent years. The uncoordinated deformation between the cutoff wall and the fillings will cause the composite geomembrane cracks. The connecting form between cutoff wall and composite geomembrane is studied through geotechnical centrifuge tests. Four model tests considering the cutoff wall, wall mud, the backfilled materials and the connecting form are performed to investigate the variation of the strain of the composite membrane. When the geomembrane is laid horizontally on the top level of the cutoff wall, it is seriously strengthened at the connection near the cutoff wall, and the geomembrane is broken down when the differential settlement increases to a certain value. When the geomembrane is first laid vertically above the cutoff wall and then horizontally extended outward, the tensile strain of geomembrane is less at the connection. The longer the distance to the connection point, the less the strain. The existence of wall mud can effectively alleviate the local strain of the geomembrane.