Authors: Yulong Luo Meili Zhan Jinchang Sheng Qiang Wu
Publish Date: 2013/09/06
Volume: 20, Issue: 9, Pages: 2578-2585
Abstract
The joint of clay corewall and concrete cutoff wall is one of the weakest parts in high earth and rockfill dams A kind of highly plastic clay is always fixed on the joint to fit the large shear deformation between clay corewall and concrete cutoff wall so the hydromechanical coupling mechanisms on the joint under high stress high hydraulic gradient and large shear deformation are of great importance for the evaluation of dam safety The hydromechanical coupling characteristics of the joint of the highly plastic clay and the concrete cutoff wall in a high earth and rockfill dam in China were studied by using a newly designed soilstructure contact erosion apparatus The experimental results indicate that 1 Shear failure on the joint is due to the hydromechanical coupling effect of stress and seepage failure The seepage failure will induce the final shear failure when the ratio of deviatoric stress to confining pressure is within 10–12 2 A negative exponential permeability empirical model for the joint denoted by a newly defined principal stress function which considers the coupling effect of confining pressure and axial pressure on the permeability is established based on hydromechanical coupling experiments 3 The variation of the settlement before and after seepage failure is very different The settlement before seepage failure changes very slowly while it increases significantly after the seepage failure 4 The stressstrain relationship is of a strain softening type 5 Flow along the joint still follows Darcian flow rule The results will provide an important theoretical basis for the further evaluation on the safety of the high earth and rockfill dam
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