1. Geotextile, also known as geotextile, is a permeable geosynthetic material made of synthetic fibers through needling or weaving. The finished product is cloth, generally 4-6 meters wide and 50-100 meters long. Geotextiles are divided into woven geotextiles and non-woven geotextiles. Geotextile has excellent filtering, drainage, isolation, reinforcement, anti-seepage, protective effect, with light weight, high tensile strength, good permeability, high temperature resistance, anti-freezing, aging resistance, corrosion resistance geotextile construction technology.
2. 1. Preparatory work before laying:
3. Foundation treatment: the site should be flat, the debris on the site should be cleaned, material preparation, according to the design size reasonable scheduling width.
4. 2. Laying and lapping methods:
5. Laying should be smooth, moderate tightness, and should be in contact with the earth surface, slope laying should be from bottom to top. Should be fixed on top and bottom, side slope should be equipped with cleats, and shall be spread over weight, hurt bad, should repair or replace, adjacent piece connection generally have lap and two methods of suture, lap width of 300 mm, generally stitch overlock sewing machine (sewing, is commonly used in the displacement may occur should be stitched, is not flat, soft soil and underwater laid on lap width increases should be appropriate, not less than 500 mm, between the upstream flow should be spread in the downstream, and bank slope and the junction of the structures should be combined with good, laying personnel should not wear shoes.
6. 3. The backfill
7. The maximum falling height of the backfill should not be more than 300mm, and the heavy earth stones should not slide down on the slope.
8. 4. Quality inspection after laying and lapping
9. In the construction site of geomemfilm, geomemfilm is composed of non-woven fabric and plastic film as impermeable base material. Its impermeable property mainly depends on the impermeable property of plastic film. At present, the domestic and foreign anti-seepage application of plastic film, mainly polyvinyl chloride (PVC) and polyethylene (PE), EVA (ethylene/vinyl acetate copolymer), they are a kind of polymer chemical flexible material, small proportion, strong elongation, high adaptability to deformation, corrosion resistance, low temperature resistance, good frost resistance. Its main mechanism is the impermeability of plastic film partition dam water leakage channel, with its greater tensile strength and elongation to withstand water pressure and adapt to the dam body deformation; And non-woven fabric is a kind of high polymer chemical short fiber material, through needle stick or hot forming, has high tensile strength and extensibility, it combines with plastic film, not only increased the tensile strength and puncture resistance of plastic film, and because the non-woven fabric surface is rough, increasing the contact surface friction coefficient, is advantageous to the composite geomembrane, and the stability of the protective layer. At the same time, they have good corrosion resistance to bacteria and chemical effects, and are not afraid of acid, alkali and salt erosion.
10. Construction technology of geomembrane
11. (1) the joint treatment of geomemfilm is the key procedure of construction, which directly affects the operation life of the project. According to the quality inspection, the hot welding method is ideal. (special adhesive can also be used) hot welding method is PE geofilm interface surface heating treatment, make the surface melt, and then through the pressure of fusion into one.
12. (2) it is better to lay the geomembrane in a certain direction. A certain PE film and PET non-adhesive layer are reserved on both sides of the geomembrane. During laying, the geomembrane trend of each unit should be adjusted to facilitate the welding of the geomembrane of the two units.
13. (3) after the geotechnical film is laid, sandbags shall be used to press it to prevent wind movement. Dirt, moisture and dust shall not be found at the edge joints.
14. (4) before welding, it is necessary to adjust the PE single film of the two edges at the seam, so that it is overlapped with a certain broadband, flat and no wrinkle.
15. (5) when welding, it is better to use experienced technical personnel for welding, and use special welding machine for welding. To adjust the temperature and speed, (or glue).
According to years of practice, the thickness of geotechnical film is no less than 0.25mm, too thin may produce blowhole, and easy to be damaged in construction and reduce the effect of seepage prevention. In the construction of geomematic film, it should be paid special attention to that the laying should not be too tight, not to wrinkle, and the splicing should be firm. The construction should be carried out in strict accordance with technical specifications, including five quality control lines, such as preparation, laying, splicing, inspection and backfilling.