3. GEOMEMBRANE INSTALLATION
3.1 Material Logistics
- 3.1.1 Transportation and On-site Storage
The geomembrane rolls shall be shipped by trailer truck to job site. The geomembrane shall be stored so as to be protected from puncture, dirt, grease, moisture and excessive heat. The damaged material shall be stored separately for repair or replacement. The rolls shall be stored on a prepared smooth surface (not wooden pallets) and should not be stacked more than two rolls high.
3.2 Earthwork
- 3.2.1 General
The owner or his representative (soil quality assurance inspector) shall inspect the subgrade preparation. Prior to liner installation the subgrade shall be compacted in accordance with the project specifications. Weak or compressible areas which cannot be satisfactorily compacted should be removed and replaced with properly compacted fill. All surfaces to be lined shall be smooth, free of all foreign and organic material, sharp objects, or debris of any kind. The subgrade shall provide a firm unyielding foundation with no sharp changes or abrupt breaks in grade. Standing water or excessive moisture shall not be allowed.
The installer, on a daily basis, shall approve the surface on which the geomembrane will be installed. After the supporting soil surface has been approved, it shall be the installer's responsibility to indicate to the inspector any changes to its condition that may require repair work.
- 3.2.2 Vegetation Control
The general contractor, if necessary, shall sterilize the area using an effective soil sterilant specifically formulated for vegetation present in the area. The sterilant shall not be harmful to the liner and shall be applied according to the recommendations of its manufacturer.
- 3.2.3 Anchor Trench
The anchor trench should be excavated to the line, grade, and width shown on the project construction drawings, prior to liner system placement. Slightly rounded corners shall be provided in the trench to avoid sharp bends in the geomembrane.
3.3 Method of Placement
The rolls shall be deployed using a spreader bar assembly attached to a loader bucket of by other methods approved by the project engineer.
The installer should be responsible for the following:
Equipment or tools shall not damage the geomembrane during handling, transportation and deployment.
Personnel working on the geomembrane shall not smoke or wear damaging shoes.
The method used to unroll the panels shall not cause scratches or crimps in the geomembrane and shall not damage the supporting soil.
Adequate loading (e.g., sand bags or similar items that will not damage the geomembrane) shall be placed to prevent uplift by wind (in case of hifh winds, continuous loading is recommended along edges of panels to minimize risk of wind flow under the panels).
- 3.3.1 Weather Conditions
Geomembrane deployment shall proceed between ambient temperatures of 32° F to 104° F. Placement can proceed below 32° only after it has been verified by the inspector that the material can be seamed according to the specification. Geomembrane placement shall not be 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 installation supervisor.
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