A geosynthetic liner system that consists of geomembrane (GMB) and geosynthetic clay liner (GCL) is vital for landfill stability analysis and it is essential to investigate the shear characteristics of GMB/GCL interface. This paper introduces a new direct shear apparatus for various geosynthetic interfaces with innovative designing, and using this apparatus 48 shear test sets of four GMB/GCL interface types are conducted under a normal stress level of 100–500 kPa and a shear rate of 0.1–100 mm/min. Effects of the surface roughness of GMB and the hydration condition of GCL on the shear stress–displacement relationship and shear strength of interfaces are investigated. Results show that the evolution of physical phenomena from shear deformation of GCL (denoted as shear phase) to frictional slip between GMB and GCL (denoted as friction phase) occurs at the critical state of peak shear strength where GMB/GCL interfaces provide the largest shear resistance. For GMB/hydrated GCL, shear phase can be further divided into pure shear phase and reinforced shear phase by initial peak strength. Thus, phased shear mechanism of GMB/GCL interface is revealed with explanations on physical and mechanical results. Some future prospects on GMB/GCL interfaces are also proposed.

由土工膜 (GMB) 和土工合成粘土衬垫 (GCL) 组成的土工合成衬垫系统对于垃圾填埋场稳定性分析至关重要，研究 GMB/GCL 界面的剪切特性至关重要。本文介绍了一种创新设计的用于各种土工合成材料界面的新型直剪装置，并使用该装置在100-500 kPa的法向应力水平和0.1-的剪切速率下进行了四种GMB/GCL界面类型的48个剪切试验组100 毫米/分钟。研究了 GMB 的表面粗糙度和 GCL 的水化条件对界面剪切应力-位移关系和剪切强度的影响。结果表明，从 GCL 的剪切变形（表示为剪切相）到 GMB 和 GCL 之间的摩擦滑移（表示为摩擦相）的物理现象发生在峰值剪切强度的临界状态，此时 GMB/GCL 界面提供了最大的剪切抵抗性。对于 GMB/水合 GCL，剪切相可以根据初始峰值强度进一步分为纯剪切相和增强剪切相。因此，通过对物理和机械结果的解释，揭示了 GMB/GCL 界面的相剪切机制。还提出了 GMB/GCL 接口的一些未来前景。揭示了 GMB/GCL 界面的相剪切机制，并解释了物理和机械结果。还提出了 GMB/GCL 接口的一些未来前景。揭示了 GMB/GCL 界面的相剪切机制，并解释了物理和机械结果。还提出了 GMB/GCL 接口的一些未来前景。