Geomembrane performance

1, geomembrane performance composite geomembrane (composite impermeable membrane) into a cloth membrane and two cloth one membrane, width 1-6m, weight 200 1500g / square meter, tensile, tear, bursting and other physical and mechanical properties is high, the product has high strength, good elongation properties, deformation modulus, acid, anti-corrosion, anti-aging, anti-seepage performance characteristics. To meet the water, municipal, construction, transportation, subways, tunnels, construction of impervious, isolation, reinforcement, crack control reinforcement, civil engineering needs. Because of its selection of polymer materials and the production process added anti-aging agent, it can be used in unconventional temperature environment. Commonly used in dams, drainage ditch seepage treatment, pollution prevention and waste treatment field. Geomembrane construction?? Geotextile geomembrane is affixed at one side or both sides of the membrane to form a composite geomembrane. In the form of a cloth membrane, two cloth one film, two films a cloth. As geotextile geomembrane layer of protection, so that impermeable layer of protection from damage. To reduce ultraviolet radiation to increase the anti-aging properties, preferably laying buried in France. Construction, the first to use a smaller diameter material leveling sand or clay base surface, and then laying the geomembrane. Geomembrane not stretched too tightly, buried in the soil at both ends of the body portion is corrugated, and finally in the shop geomembrane layer of about 10cm over layer of fine sand or clay. Lined with 20-30cm stone (or precast concrete blocks) for the anti-scour protection layer. Construction, should try to avoid the stones hit directly on the geomembrane, preferably side to side laying protective layer construction. Geomembrane connection with the surrounding structures should be used to the pressure of the expansion anchor bolts and steel connecting parts to brushing emulsified asphalt (thickness 2mm) adhesive to prevent leakage there. Geomembrane joint processing is a key step directly affect seepage effect. General seams ways are: ① lap: lap width should be greater than 15cm; ② heat welding: suitable for thicker geomembrane base, weld lap width of not less than 5CM (not recommended glued, soaked in water for a long time. easy to open plastic, impervious poor results.)? Based on years of proven, geomembranes thickness not less than 0.25mm, too thin may have holes, and the effect is reduced seepage easily damaged during construction. Geomembrane construction, laying particular attention to do not too tight, can not fight wrinkles, stitching to secure. In strict accordance with the technical specifications of construction, the good preparation, laying, splicing, testing and backfilling five quality. Due to impermeable geomembrane good effect, at present, water-saving irrigation district reconstruction Baojixia Corollary projects, the extensive use of the material, has been widely praised design, construction units. Geomembrane Features:? Width of 6 meters, is currently the most wide-composite film high resistance to puncture strength, friction coefficient good aging resistance, adapt to a wide range of ambient temperatures excellent resistance to drainage performance is suitable for water, chemicals, construction??? ?, transportation, subways, tunnels, waste disposal sites and other projects Main Specifications:?? 400 500 600 700 800 900 1000 REMARKS 0.25 to 0.35 0.3 to 0.5 breaking strength KN / m??????????? 5? 75? 100? 120? 140? 160? 180? CBR bursting strength KN? 11? 15? 19? 22? 25? 28? 30? vertical and horizontal? Tear strength KN? 0.15? 0.25? 0.32? 0.40? 0.48? 0.56? 0.62? crossbar to?. Geomembrane with impermeable plastic film as a substrate, and non-woven geotextile composite made of impermeable material, its performance depends on impervious impermeable plastic film performance. At present, the application of impermeable plastic film at home and abroad, mainly polyvinyl chloride (PVC), polyethylene (PE), ethylene / vinyl acetate copolymer (EVA), which is a flexible material polymer chemistry, the proportion of small, extension of the strong ability to adapt to high deformation. Corrosion resistance, low temperature, frost performance. The main mechanism of the non-permeable plastic film is cut off earth leakage passage, with its greater tensile strength and elongation to withstand water pressure and adapt to dam deformation; and non-woven staple fiber is a polymer chemistry material, through needle stick or hot forming, high tensile strength and elongation, combined with plastic film after it, not only increases the tensile strength and puncture resistance of the plastic film, and because of non-woven surface roughness and increase the contact surface of the friction coefficient, it is conducive to protective layer of geomembrane and stability of. At the same time, they have good bacteria and chemical resistance to aggressive, not afraid of acid, alkali, salt erosion. Now a kind of new type of composite geomembrane - Warp composite geomembrane. With the new composite made of composite geomembrane geotextile material. Unlike warp geomembrane geomembrane. Its greatest feature is the intersection of warp and weft bend, each in a flat state. Tie the line to both tightly and evenly fully synchronized external force, stress distribution, and when the applied force tearing the instantaneous, yarn along rip pro set to increase tear strength. When the warp composite, namely the use of warp bundled line between the weft and non-woven waterproof acupuncture staple fiber geotextile layer repeatedly walk through, so it became one of the three series. Thus warp geomembrane has the characteristics of both high tensile strength, low elongation, and both waterproof geomembrane. Therefore, a warp of geomembrane increased with the reinforcement, isolation, protective effect of impermeable material. It is the high level of international applications today geotextile composites. Geomembrane useful life of the main problem is whether the loss of seepage from the impermeable plastic film role may be, according to the Soviet national standard, with a thickness of 0.2m hydraulic plus stabilizers of polyethylene film, the conditions under water Work up to 40 to 50 years of age, working in conditions of life under water 30 to 40 years. Therefore, the useful life of geomembrane sufficient to meet the useful life of the dam seepage. 2) Selection of composite geomembrane Currently, the domestic production more geomembrane manufacturers, product specifications also varied, with a cloth membrane, two films a cloth, two cloth one membrane, two multi-cloth fabric two more film and film, etc. . Models are 200g / m2 ~ 1000g / m2, etc., can be requested by the user according to their actual situation, as required by the manufacturers alone. Table 5.5.3.1 lists the key performance indicators Xinyu geotextile material plant produced some products for design reference use. Chart Product main performance table Model Specification Indicators Project? WCS-1? WCS-2? WCS-3? WCD-1? WCD-2 a cloth membrane composite geomembrane? Two cloth one film geomembrane 220? 500? 600? ? 300 500 deviation of mass per unit area (%) & le ;? First Grade 6.5 5.0 5.0 6.5 5.0 9.0 8.0 7.0 8.5 qualified product thickness 8.0?????????? (mm & ge;)? First grade 0.30? ? 1.40? 2.50? 0.40? 1.75 Qualified? 0.25? 1.30? 2.40? 0.35? 1.65 aspect to strip tensile strength (N / om)? & ge ;? First grade? 70? 300? 450? 110? 400 qualified product? ball bursting strength (N)? & ge ;? First grade? 200? 500? 900? 200? 900 Qualified? impermeability strength (Mpa)? First Class? 0.4Mpa pressure water seepage? 0.7? Mpa pressure water seepage? 0.7? Mpa pressure impermeable? 0.4Mpa pressure water seepage? 0.7? Mpa pressure impervious Qualified? look? First Class? cloth smooth, no holes, oil viscosity and film close together, no stratification qualified products based on product performance table 5.5.1.3 mainly based on the specific circumstances of the first week of reservoir design uses WCD -? Type 1 two cloth one film geomembrane, its specifications for the 300g / m2, width 1.9m. 4) the design of composite geomembrane composite geomembrane body structure from the base surface, geomembrane, a protective layer, stone (or concrete) total of four layers slope (below 5.5.4.1), now the layers Design are as follows: Composite geomembrane structure cross-sectional view (Unit: mm) ① laying the base surface design (ie dam shell surface treatment on request) geomembrane to prevent spread fill along the sliding surface soil layer for increased protection stability layer (including armor), and the upstream dam shell laying a table surface excavation stages, each stage height of 0.3m, horizontal width ratio may be based on slope, slope design of 1:?? 1.0 (Figure 5.5.1.3), the rear excavation shaping the surface of brick, stone and * root trees cleaned, and the surface of the matter with a green light and smooth. ② geomembrane designed in accordance with Table 5.5.1.3 of the main features of the product can be combined with the specific circumstances of the first week of the reservoir, design selection geomembrane WCD-1 type two cloth one film. ③ design a protective layer of geomembrane seepage effect depends on the soundness of the process of construction and operation of plastic film, in order to prevent livestock trampling, animal and plant damage and reduce the effect of light and heat, because they are macromolecular synthetic polymer, it should be In particular, avoid direct sunlight, it should be spread on the protective layer of geomembrane. The particle diameter of the protective layer is not too large, otherwise it will pierce the geomembrane, general particle diameter of the protective layer to the following formula to approximate estimates. Where: maximum particle diameter d-- protective layer of soil material; k-- safety factor, the project take k = 5; [σ] - geomembrane tensile strength allows [σ] = 5.5Mpa; p- - withstand the maximum head, take P = 0.1Mpa; - geomembrane thickness, taking = 0.2mm (thickness of plastic film?). The data on each of the above into the equation too: For security reasons, the actual soil material requires a maximum particle diameter d is not greater than 6mm, so this project uses sieve silty clay, and other requirements as the dam of Earth Filling requirements. The protective layer take 200mm, 100mm below the soil with a sieve, sieve above 100mm non-soil. Non sieve soil, should be singled out large stones and other debris. ④ armor slope surface is designed as retaining structures to withstand storms pressure, so there must be measures to protect the surface, this large engineering dry stone masonry surface protection. Rock armor must be hard, dense, long-term resistance to weathering, and there must be individual weight, able to withstand the effect of pressure waves and water erosion force. The weight of the rock armor and armor thickness and Q refer to "dike design specifications" GB50286-98) Appendix D.3 method of determining. The formula: where:?? Q-- main surface rock armor protection of individual quality (t) rb-- severe artificial stone (KN / m3) rb = 24KN / m3 r-- severe water r = 10KN / m3 H-- design slope height? H = KD-- stability factor, KD = 5.5 t-- stone protective surface layer thickness n-- rock armor layers of n = 1 c-- coefficient? c = 1.4 m-- slope gradient is calculated: Q = 48kg, t = 0.29m, taking rock blocks armor thickness t = 0.3m. In order to prevent storm water will dam shell protective layer of clay particles away, lay in the rubble armor thickness of 0.1m of gravel (sand and gravel) as a cushion and filter layer. (5) Geomembrane impervious element construction technical process requirements ① the first week of composite geomembrane dam taken while digging, side shop, while tamping, while retaining the zone circulating operation, the construction process shown in Figure 5.5 .3.2 flowchart of FIG geomembrane construction ② base surface cleaning base surface must be cleaned up in accordance with design requirements, it is crucial to ensure that anti-seepage effect, especially on sharp stones, roots and other debris to be thoroughly cleaned, group surface does not allow partial bump phenomenon, the cleaned substrate surface or use a ram plate tamper rammer tight, making dense formation. Filming laying, must and laying ③ upper and lower geomembrane. Between the film and the film and the film and the substrate surface to flatten snapping, but not the film is pulled too tight, usually slightly loose a little, but you can not leave bubbles in the film at the end. Because before geomembrane relatively thin and very light, later laid, not laid in the protective layer can easily be moved with the wind, so the area should not be a laying of large, the best side to side laying protective layer of soil cover material. Provide information, according to the manufacturer of composite geomembrane width 1.0 ~ 1.9m, 1.9m width of the projects selected to reduce the joint use of materials. Fitting hot sticky, adhesive, lap and other methods, the project design uses adhesive seam width 50mm. If it is found geomembrane puncture or tear the place, be sure to use three times the area of ??subsidies damaged geomembrane good adhesive. ④ protective layer and surface protection against geomembrane 10cm thick protective layer of soil material must be screened, not allowed to have more than 6mm diameter particles, or easily punctured geomembrane. The protective layer of soil material must use the pounding dense, ensure the dry bulk density of 1.5 or more, and sampling and testing at any time. The protective layer and backfill stone masonry surface protection, must be light, so as not crashed geomembrane. Here in stone armor, shall be covered by filling 100mm thick gravel or gravel cushion to prevent the water level changes due to the impact, storms and other factors scour protection layer of soil material. Take artificial rock blocks hung paving stones should be closely embedded solid, surface stone individual weight greater than 48kg, all voids are filled with a small stone. ⑤ surrounding junction processing requirements surrounding junction dealing composite geomembrane close links with the surrounding soil, plugging seepage entrance, truncated lateral leakage path to prevent water seepage into the geomembrane bottom surface, the formation of blisters, fall in the water level When burst geomembrane. So be sure to dig the surrounding junction cut sink and geomembrane buried tank. See specific layout design. Speaking geomembrane must emphasize national technical standards: GB / T17642-1998 ?, national standards for a variety of geomembrane have specific parameters. The process according to the difference is mainly thermal compound geomembrane geomembrane law and lamination method geomembrane points. Geomembrane is a generalized name: non-woven geotextile, woven geotextile boob or polyethylene woven geotextile composite, with thermal compound method or polyethylene PE film lamination can be called directly geomembrane. Composite geotextile and geomembrane Some products are different names, product referred to is the same. Since the geotextile is no new material specifications call for names, causing confusion and geomembrane defined specifications. India has recently developed jute geotextile - Strictly speaking all used in the civil engineering class film-like material may be collectively referred to as geomembrane, called geomembrane is to combine two materials together or isolated use of impermeable Effect of geomembrane composite materials.