Experimental research on shear failure mechanism of hydrated needle-punched GCLs
LIN Hai1, 2, SHI Jian-yong2, QIAN Xue-de1, 3
1. School of Civil Engineering and Architecture, Nanchang University, Nanchang 330031, China; 2. Key Laboratory of Geomechanics and Embankment Engineering of the Ministry of Education, Hohai University, Nanjing 210098, China; 3. Michigan Department of Environmental Quality, Lansing 48933, USA
Abstract：The internal face of GCLs is one of the weak interfaces within the composite impermeable liners. Their internal shear strength is enhanced by the reinforced needle-punched fiber. Through comprehensive analysis of the existing internal shear test results of needle-punched GCLs and large simple shear test results of GCL+GM composite liners, small peak stress is found to appear at small displacements in internal shear stress-displacement curves of hydrated GCLs. By conducting shear tests on hydrated GCLs-encased sodium bentonite, combined with theoretical analysis, the occurrence of the small peak stress at small displacements is confirmed to be the inherent feature in the stress-displacement curve of hydrated GCLs, and the small peak stress represents the shear strength contribution from GCL-encased bentonite. On the basis of the small peak stress phenomenon in the stress-displacement curves of needle-punched GCLs, the contribution of the reinforced fiber to the shear strength is obtained quantitatively, and the whole process of internal shear failure and stress-displacement development of GCLs is analyzed based on the failure mechanism. Considering the contribution of each part of needle-punched GCLs to the shear strength, a peak shear strength criterion model which can reflect the failure mechanism of needle-punched GCLs is proposed.
林海, 施建勇, 钱学德. 水化针刺GCL剪切破坏机理的试验研究[J]. 岩土工程学报, 2017, 39(8): 1374-1380.
LIN Hai, SHI Jian-yong, QIAN Xue-de. Experimental research on shear failure mechanism of hydrated needle-punched GCLs. Chinese J. Geot. Eng., 2017, 39(8): 1374-1380.
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