M. Placement of soil shall not occur on Geomembrane that is under stress due to
thermal contraction or other causes, or that has large winkles that may fold
over and crimp, or when the ambient air temperature, measured 6-inches
above the Geomembrane, is greater than 104°F or lower than 40°F without
prior approval of ENGINEER. Panels under tensile stress due to thermal
contraction or any other cause shall be cut and a patch shall be placed to
provide compensation for Gcomembrane contraction. Equipment shall not be
operated directly on the GGomembrane during placement of soil.
N. Geomembrane panels shall be secured in the anchor trench as indicated on the
Drawings.
O. All pipe penetrations through the Gcomembrane shall be sealed with a boot of
the same material as the panels, meeting the same resin specifications, and
installed in accordance with the Drawings.
3.4 GEOMEMBRANE SEAMING
A. Geomembrane seams shall be arranged so that the seams are oriented parallel
to the line of maximum slope. Cross or butt seams on slopes, seams located in
corners, and unusual geometric panel shapes shall be minimized and shall be
installed such that the upgradient sheet is installed over the edge of the
downgradient sheets.
B. The seam identification system shall be related to and be compatible with the
panel identification system.
C. Seaming equipment shall be equipped with temperature gauges and readout
devices that enable continuous monitoring of equipment temperatures during
seaming. Electric generators shall be capable of providing constant voltage
under load and shall be underlain with a splash pad to collect spilled fuel or oil
when located on the GGomembrane.
D. Surfaces to be seamed shall be overlapped a minimum of 4 inches and cleaned
of moisture, grease, dust, dirt, debris, and any other foreign material. No
solvent or adhesive shall be used for seaming without approval from the
manufacturer and the ENGINEER.
E. Where moisture or dirt interferes with the seam, a protective sheet of plastic
shall be placed below the seam overlap to protect the panels being seamed.
This may consist of a “rub sheet” of plastic that is pulled along beneath the
seaming apparatus.
F. Surfaces to be seamed using extrusion welding shall be cleaned of oxidation by
disc grinder not more than one hour before extruding the seam. Abrasion of
the seam area with the disc grinder shall not extend beyond the extrusion bead
area unless inspected and approved by the CQA Consultant. Tack welding of
File No. 3066.09.00 Geomembrane 02550 - 9 of 14 December 2017
