竖向应力作用下GCL的膨胀特性和渗透性能

近年来,土工织物膨润土垫(GCL)被越来越多地应用到各种防渗工程之中,它的防渗有效性也成为了设计人员和研究人员所关注的焦点。GCL的防渗有效性包括渗透性能、吸附能力和内部剪切强度三个方面。通过水化膨胀试验和渗透试验研究了GCL在竖向应力作用下的膨胀特性和渗透性能,并分析了正应力和加压水化顺序的影响。试验结果表明:(1)随着竖向应力的增大,GCL的膨胀量不断减小,而GCL的渗透系数则出现先减小后略有增大的规律;(2)水化加压顺序对GCL的膨胀量和渗透系数均有影响;(3)在实际工程应用中,GCL铺设完成后在堆载之前最好完全水化,这样能够大大提高GCL的防渗有效性。

Swelling characteristics and hydraulic properties of GCLs under vertical stress

Recently,geosynthetic clay liners(GCLs) have been more and more used in different anti-seepage engineering projects.Their anti-seepage availabilities include hydraulic properties,absorption ability and internal shear strength and GCLs become a focus of designers and researchers.Swelling characteristics and hydraulic properties of GCLs under vertical stress were studied through hydration swelling tests and permeation tests.It was indicated that:(1) swelling of GCLs decreased with the increasing of vertical stress,but the hydraulic conductivity of GCLs decreased at the beginning,and then increased a little;(2) hydration-loading sequence had impact on both swell and hydraulic conductivity of GCLs;(3) in practice,GCLs had better been fully hydrated before loading on them,thus the anti-seepage availability could be greatly improved.