engleski

Extrusion of Hydrated Bentonite through the Woven Geotextile of GCL and the Influence on GCL/GM Interface Shear Strength

Testing program to determine the interface shear strength between needle-punched geosynthetic clay liner (GCL) and a textured geomembrane is presented. Half of the tests were done on prehydrated GCL samples. Bentonite was observed to extrude through the woven geotextile of the GCL’s onto the geomembrane for specimens prehydrated at low normal stresses, consolidated and afterwards sheared at higher normal stresses. The parameter cextrusion was defined as a unit of measurement for the quantity of bentonite extruded onto the contact area. Greater bentonite extrusion gave the lower value of interface shear strength, i.e. interface secant friction angle. The interface shear strength also decreases with an increase in normal shear stress for both prehydrated and non- prehydrated samples. Guidelines for calculating the decrease of interface secant friction angle due to the increase of normal stress and bentonite extrusion is established.

extrusion; bentonite; GCL

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