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FA <br />91998 GeoSyntec consultants <br />TEST PROCEDURES O, 9 <br />TEST SERIES NUMBER: 2 <br />Test Specimen Configuration (from top to bottom) and Placement Conditions: <br />• upper shear box: clay liner initially placed at a dry unit weight of 106.3 to 106.7 pcf <br />and a moisture content of 19.8 to 20.6% for the test series. Final moisture content <br />ranged from 30.2 to 34.1 % for the test series; o T <br />• Tensar DC4205 geocomposite; and <br />l � <br />• lower shear box: bedding layer of compacted concrete sand. C'\1'— :� .3 <br />Test Interfaces: upper soil against geocomposite <br />Test Procedures for Each Normal Stress Condition: <br />• A fresh specimen of concrete sand was compacted into the lower shear box by hand <br />tamping to a relatively dense state under dry conditions forming a 3 in. thick <br />bedding layer. <br />• A fresh specimen of geocomposite was trimmed from the bulk sample and attached <br />to the lower shear box with mechanical compression clamps. <br />• A fresh specimen of the upper soil was compacted away from the geocomposite <br />specimen and then placed on top of the geocomposite specimen for testing. The <br />initial target compaction conditions (i.e., dry wit weight and moisture content) <br />corresponded to 90% of maximum dry unit weight and 6 percentage points wet of <br />optimum moisture content based on the results of a modified Proctor compaction <br />test conducted by GeoSyntec and reported elsewhere. <br />• Soaking Conditions: the entire test specimen was soaked together in tap water for <br />24 hours under a normal stress of 125 psf. The soaking normal stress was applied <br />prior to immersion. <br />`• Test normal stresses: 125, 250, and 350 psf. <br />• Test normal stress was applied within ten minutes of removal of the soaking <br />normal stress and shear commenced immediately after the application of the test <br />normal stress. <br />• Constant shear displacement rate: 0.04 in/min. <br />• The direction of shear for each interface direct shear test was in the direction of <br />manufacture (machine direction) of the Tensar geocomposite sample. <br />• Each test was sheared until a minimum total shear displacement of 2 in. was <br />achieved. <br />WL0148-021SGI98030 2 08.21.98 <br />C <br />.10 <br />