2009-07-15_REVISION - M1980244 (39)

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amec'AN • done during any precipitation, in the presence of excessive moisture (e.g., fog, rain, dew) or in the presence of excessive winds, as determined by the CQA Monitor. F. Following the installation of the geomembrane, an examination of the entire surface shall be conducted to detect potentially harmful rocks or other objects. Any such objects will be removed and the geomembrane repaired by the CONTRACTOR, at no cost to CC&V. 3.06 FACTORY SEAMS MANAGER and CERTIFYING ENGINEER may require CONTRACTOR to test up to as much as twenty percent (20%) of factory fusion welds (non-destructive air pressure test) in the field to verify factory test results. Additional testing at CONTRACTOR's expense will be required if failed tests are obtained in the field. 3.07 FIELD SEAMS A. Seam Layout Seams shall be oriented parallel to the line of maximum slope, i.e., oriented down, not across the slope. In corners and odd-shaped geometric locations, the number of field seams shall be minimized. • 2. No horizontal or base T-seam or tie-in seams shall be closer than five (5) feet from the toe of the slope. Seams shall be aligned to prevent wrinkles and "fish mouths." If a fish mouth or wrinkle is found, it shall be relieved and capped. Panels of geomembrane will have sufficient overlap provided to allow peel tests to be performed on the seam. B. Seaming Method The procedure used to temporarily bond adjacent panels together shall not damage the geomembrane; in particular, the temperature of hot air at the nozzle of any spot welding apparatus shall be controlled such that the geomembrane is not damaged. 2. CONTRACTOR shall use double fusion welding as primary method. of seaming adjacent field panels. a. For cross seam tees associated with fusion welding, CONTRACTOR shall patch panel intersections consisting of three or more panels and extrusion weld to a minimum distance of 4 inches on each side of patch. The edge of the sheet shall be ground to a 45° angle prior to welding. b. Place a protective layer, e.g., insulting plate or fabric, beneath hot welding apparatus after usage. C. When subgrade conditions dictate, use a moveable protective layer directly below each overlap of geomembrane that is to be seamed to prevent buildup of moisture between sheets and prevent debris from collecting around pressure rollers. • Section 02776 Page 15 of 22 Geomembrane SAProjects\1125 CC&V Phase 5 VLF\I - Tech Specs\Arequa IFC Specs\02776.r1.doc September 3, 2008 Revision 1