2012-02-28_REVISION - M1980244 (69)

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Soil /Geosynthetic Interface Test Report Project Valley Leach Facility - Cripple Creek & Victor Project No. DV108 -130.7 Lab No. Date Tested 7/24 - 7/27/07 Tested By spb Test Description SWTP -99 vs 80 mil Text HDPE vs. Overliner (Composite) Checked By spb Sample I.D: Normal Stress Range, psf 7200 14400 21600 28800 Total No. of Points Requested 4 Geomembrane Data SWTP -99 vs 80 mil Text HDPE vs. Overliner (Composite) Test No. (file) 27026A -D Manufacturer Lot No. Roll No. Textured? Yes Peak to Peak Thickness, mil 80 Specified Thickness, mil 80 Test Target Parameters Moisture Content, % 17.5 Dry Density, pcf 105.8 Observations: The clay (subgrade) was compacted in the lower shear box half with dimensions of 10 in. x 12.0 in. x 2.5 inches deep. The subgrade surface was sprayed with water prior to placing the geomembrane coupon on it. The coupon was left floating and not anchored to either the top or bottom box halves. The overliner was placed loosely and lightly tamped prior to saturating with tap water. With the loading plate assembled and the normal force applied the sample was allowed to consolidate approximately 8 hours prior to initiating shear displacement. No punctures or tears were observed in the coupons upon completion of the test. The failure plane existed the interface between the smooth side and the overliner at the 50 psi stress and between the subgrade and the textured surface for all others. Upper Box Half Description Overliner Poorly graded GRAVEL with silt and sand Lower Box Half Description SWTP -99, compacted to approx. 95% MDD at OMC +2% Normal Stress Top Box Fixed Position - (stationary) 80mil Textured HDPE Gap Overliner (textured surface against subgrade) Outer container (allows for saturation) —� /� Shear r Direction SWTP -99 (subgrade) Default Test Descriptions (unless noted otherwise) 1 The test was performed in a Boart Longyear 300mm shear device, using an 8inch x 8 inch square insert. 2 The rate of displacement was 0.02 in. /min. (0.50 mm/min.) for each stress. 3 The geomembrane coupon was not anchored. The coupon was sandwiched between the overliner and rested on the compacted subgrade. 4 Load increments were recorded in 10 lbf increments. 5 The Geosynthetic coupons are available for inspection at the lab. 6 The samples were allowed to consolidate for approximately 8 hours prior to initializing shear movement. The overliner was saturated with tap water and allow to fully drain prior to initializing shear displacement. 7 The geomembrane was tested in machine direction. No testing was performed in the cross - machine direction. Knight Piesold and Co. Geotechnical Laboratory 8/7/2007 Knight Resold Direct Shear Test ASTM D 5321 108 -130 -7 Cripple Creek rev 2