This paper provides insight into the causes of post-peak strength loss for textured geomembrane (GMX) and nonwoven geotextile (NGT) interfaces. The NGT can be part of a geosynthetic drainage composite (GDC) or a stand-alone NGT. The study used ring shear tests where one of the two interface materials was replaced after reaching a residual strength condition and the test was restarted to measure the change in interface strength. The interface strength loss from peak to large displacement (LD) strength primarily comes from three mechanisms: (1) geomembrane wear, (2) breakage and combing of fibers in the NGT, and (3) reduction of the hook and loop effect between GMX asperities and fibers of the NGT. The source of interface strength loss from LD strength to the residual value mainly comes from breakage and continuous combing of NGT fibers parallel to the direction of shear in ring shear tests. Scanning electron microscopy photographs of the GMX and NGT before and after shearing confirm wear and smoothing of GMX asperities and the combing of NGT fibers in the direction of shear.

中文翻译：

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GMX/GDC 强度损失机制

本文深入探讨了纹理土工膜 (GMX) 和非织造土工织物 (NGT) 界面峰后强度损失的原因。NGT 可以是土工合成排水复合材料 (GDC) 的一部分，也可以是独立的 NGT。该研究采用环剪试验，在达到残余强度条件后更换两种界面材料中的一种，然后重新开始测试以测量界面强度的变化。从峰值强度到大位移（LD）强度的界面强度损失主要来自三个机制：（1）土工膜磨损，（2）NGT中纤维的断裂和梳理，以及（3）GMX之间钩环效应的减少NGT 的粗糙度和纤维。从LD强度到残值的界面强度损失的来源主要来自环剪试验中NGT纤维平行于剪切方向的断裂和连续梳理。剪切前后 GMX 和 NGT 的扫描电子显微镜照片证实了 GMX 粗糙度的磨损和平滑以及 NGT 纤维在剪切方向上的梳理。