How to Lay Geotextiles

Geotextile, also known as geotextile, is a water-permeable geosynthetic material made of synthetic fibers by needling or weaving. Geotextile is one of the new materials geosynthetic materials, the finished product is cloth-like, the general width is 4-6 meters, the length is 50-100 meters. Geotextiles are divided into woven geotextiles and non-woven filament geotextiles.

Geotextile laying method:

1. With manual rolling, the cloth surface should be smooth, and appropriate deformation margin.

2. The installation of filament or short filament geotextile is usually used by several methods of bonding, stitching and welding. The width of stitching and welding is generally more than 0.1m, and the lap width is generally more than 0.2m. Geotextiles that may be exposed for a long time should be welded or stitched.

 Geotextile Stitching:

All stitching must be done continuously (for example, spot stitching is not allowed). The geotextile must overlap at least 150mm before overlapping. The minimum stitch distance from the woven edge (the exposed edge of the material) is at least 25mm.

The stitched geotextile joint most includes a line of chain stitch stitch. The thread used for stitching should be a resin material with a minimum tension of more than 60N, and have chemical corrosion resistance and UV resistance equal to or exceeding that of geotextiles.

Any "missing stitches" in the stitched geotextile must be re-stitched at the affected area.

Appropriate measures must be taken to prevent soil, particulate matter or foreign substances from entering the geotextile layer after installation.

The lapping of cloth can be divided into natural lapping, sewing or welding according to the terrain and the function of use.

In the construction, the geotextile above the geomembrane uses natural lap, and the geotextile above the geomembrane uses seam or hot air welding. Hot air welding is the preferred connection method of filament geotextile, that is, the connection of two pieces of cloth is heated at high temperature at a hot air gun, so that part of it reaches a melting state, and immediately uses a certain external force to make it firmly bonded together. In the case of wet (rain and snow) weather can not be thermal adhesive connection, geotextile should take another method a suture connection method, that is, a special sewing machine for two-line suture connection, and the use of chemical UV resistant suture line.

The minimum width is 10cm when stitching, 20cm when natural lap and 20cm when hot air welding.

For sewing, to use the same quality as geotextile suture, suture line to use chemical damage resistance and ultraviolet irradiation ability stronger material.

Geomembrane is laid after the geotextile is laid and approved by the on-site supervision engineer.

The geotextile on the geomembrane is laid as above after the geomembrane is approved by Party A and the supervisor.

The two layers of geotextile above and below the membrane should be buried in the anchoring groove together with the geomembrane.

The basic requirements of geotextile laying:

1. The joint must intersect with the slope line; Where there is balance with the foot of the slope or where there may be stress, the distance between the horizontal joints shall be greater than 1.5m.

2. On the slope, anchor one end of the geotextile, and then put the coil down on the slope to ensure that the geotextile maintains a tight state.

3. All geotextiles must be pressed with sand bags, sand bags will be used during the laying and retained until the laying of the above layer of material.

Geotextile laying process requirements:

1. Basic inspection: check whether the basic level is smooth and solid, if there is a foreign body, the matter 

should not be handled properly.

2. Test shop: according to the site situation, determine the geotextile size, cut to the test shop, cut the size 

should be accurate.

3. Check whether the width of the Sarah is appropriate, the lap should be smooth, moderate tightness.

4. Positioning: Use a hot air gun to bond the lap parts of the two geotextiles, and the spacing of the bonding

 points should be appropriate.

5. When stitching the overlap part, the suture line should be straight and the stitches should be even.

6. After stitching, check whether the geotextile is laid smoothly and whether there are defects.

7.If there is not the required phenomenon, should be repaired in time.