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c 2000 GeoSyntec Consultants <br />INTERFACE DIRECT SHEAR TESTING <br />TEST PROCEDURES AND CONDITIONS <br />TEST SERIES NUMBER: 1 <br />Test Specimen Configuration (from top to bottom) and Placement Conditions: <br />• upper shear box: drain cover fill initially placed at a dry unit weight of 112.3 pcf and a moisture content <br />of 5.4 %. Final moisture content was 12.2% for the test series; <br />• 80-mil GSE smooth VLDPE geomembrane; and <br />• lower shear box: iron clad soil liner material initially placed at a dry unit weight of 115.3 pcf and a <br />moisture content of 12.6 %. Final moisture content was 12.4% for the test series. <br />Test Interface: upper soil against geomembrane against lower soil <br />Test Procedures for Each Normal Stress Condition: <br />• A fresh specimen of the iron clad soil liner materia: was compacted into the lower box by hand tamping. <br />The initial target compaction conditions (i.e., dry unit weight and moisture content) correspond to 95% <br />of maximum dry unit weight and the optimum moisture based on a standard Proctor compaction test as <br />provided by CC&V. <br />• A fresh specimen of the geomembrane was trimmed from the bulk sample and was placed above the <br />lower soil. The geomembrane was not attached to either the lower or upper shear boxes. With this <br />method of test specimen preparation, shear failure would occur at the weakest interface within the test <br />cross- section. <br />• A fresh specimen of the drain cover fill at its as- received moisture content was compacted directly on top <br />of the geomembrane specimen. There was no initial target compaction condition of dry unit weight <br />specified by CC&V. <br />• Wetting the drain cover fill and the top of the geomembrane were wetted with tap water prior to <br />shearing. Tap water was poured through the drain cover fill and allowed to drain at the interface <br />between the drain cover fill and the top of the geomembrane. <br />• Test normal stress: 500 psi. <br />• Constant shear displacement rate: 0.04 in/min. <br />• Shear box size: 6 in. by 6 in. <br />• Each test was sheared until a minimum total shear displacement of 2 in. was achieved. <br />GLI1126/SGI00011.DOC 1 00.02.25 <br />