水化状态对含针刺GCL复合衬里抗剪强度的影响分析

Effect of hydration state on shear strength of composite liner with needle-punched GCL

针刺GCL和HDPE土工膜(GM)在防渗工程中应用广泛,含多层界面的复合衬里整体抗剪强度是边坡稳定性分析的关键。介绍了含针刺GCL复合衬里的大单剪试验方法,并且对比分析了针刺GCL初始状态分别为干燥和完全水化两种情况下的复合衬里抗剪强度。结果表明,复合衬里的剪切破坏不会发生在干燥针刺GCL内部界面,而GCL干燥状态下的复合衬里单剪强度未必高于GCL完全水化状态下的复合衬里单剪强度。结合含GCL复合衬里的剪切破坏机理,阐述了针刺GCL的水化状态对复合衬里抗剪强度的影响。含GCL复合衬里在不同水化状态下的界面滑移稳定性都应引起工程人员的重视。

Needle-punched GCL and HDPE geomembrane(GM) are widely used in impermeable engineering, and the whole shear strength of multi-layer composite liner with GCL is crucial for the slope stability. A large simple-shear testing method for composite liner with needle-punched GCL is introduced, and the whole peak shear strength of composite liner with dry GCL is compared with that with GCL in hydration state. The results show that the shear failure of composite liner does not occur at the dry GCL internal face. The shear strength of composite liner with dry GCL is not always larger than that with hydrated GCL. Combined with the shear failure mechanism of composite liner with GCL, the influence of GCL hydration state is illustrated for the shear strength of composite liner. The translational interface stability of composite liner with GCL in different hydration states should draw engineers' attention.