- Use manual rolling, the cloth surface should be flat, and the deformation allowance should be properly left.
- The installation of filament or short-filament geotextile usually uses lap, stitch, and welding methods. The width of stitching and welding is generally more than 0.1m, and the width of overlap is generally more than 0.2m. Geotextiles that may be exposed for a long time should be welded or stitched together.
- Stitching of geotextile:
All stitching must be performed continuously (for example, spot stitching is not allowed). Before overlapping, the geotextile must overlap less than 150mm. The smaller stitch distance is at least 25mm from the selvage (the exposed edge of the material).
The sewn geotextile seams also include a line of chain stitching with a chain lock. The thread used for stitching should be a resin material with a smaller tension exceeding 60N, and has the chemical resistance and ultraviolet resistance equal to or exceeding that of the geotextile.
Any “drop stitches” on the sewn geotextile must be re-sewn in the affected area.
Corresponding measures must be taken to prevent soil, particulate matter, or foreign matter from entering the geotextile layer after installation.
The cloth lap joint can be divided into natural lap joint, seam joint, or welding according to the function of terrain use.
- During construction, the geotextile on the geomembrane is naturally lapped, and the geotextile on the geomembrane is sewn or welded by hot air. Hot air welding is a method of connecting filament geotextiles, that is, using a hot air gun to heat two pieces of cloth at a high temperature instantaneously to make part of it reach a molten state, and immediately use a certain external force to bond it firmly together. When hot bonding is not possible in wet (rainy and snowy days) weather, geotextiles should adopt another method—the stitching connection method, which is to use a special sewing machine for double-thread suture connection and use chemical UV-resistant sutures.
The smaller width is 10cm when stitching, the smaller width is 20cm when natural overlap and the smaller width is 20cm when hot-air welding.
- For the seaming, use the suture thread with the same quality as the geotextile, and the suture thread should be made of material with stronger resistance to chemical damage and ultraviolet light.
- After the geotextile is laid, the geomembrane shall be laid after approval by the site supervision engineer.
- The geotextile on the geomembrane is laid after the geomembrane is approved by Party A and the supervisor.
- The geotextiles of each layer are numbered TN and BN.
- The two layers of geotextile on the top and bottom of the membrane should be buried in the anchor groove together with the geomembrane where there are anchoring grooves.