Geotextile, also known as geotextile, is a permeable geosynthetic material made of synthetic fibers by needle punching or weaving. Geotextile is one of the new geosynthetic materials. The finished product is cloth-like, with a general width of 4-6 meters and a length of 50-100 meters. Geotextiles are divided into woven geotextiles and non-woven filament geotextiles.
Features
1. High strength, due to the use of plastic fibers, it can maintain sufficient strength and elongation in wet and dry conditions.
2. Corrosion resistance, long-term corrosion resistance in soil and water with different pH.
3. Good water permeability There are gaps between fibers, so it has good water permeability.
4. Good anti-microbial properties, no damage to microorganisms and moths.
5. The construction is convenient. Because the material is light and soft, it is convenient for transportation, laying and construction.
6. Complete specifications: The width can reach 9 meters. It is the widest product in China, mass per unit area: 100-1000g/m2
1: Isolation
Polyester staple fiber needle-punched geotextiles are used for building materials with different physical properties (particle size, distribution, consistency and density, etc.)
materials (such as soil and sand, soil and concrete, etc.) for isolation. Make two or more materials do not run off, do not mix, keep the material
The overall structure and function of the material enhance the bearing capacity of the structure.
2: Filtration (reverse filtration)
When the water flows from the fine soil layer into the coarse soil layer, the good air permeability and water permeability of the polyester staple fiber needle-punched geotextile are used to make the water flow.
Through, and effectively intercept soil particles, fine sand, small stones, etc., to maintain the stability of soil and water engineering.
3: Drainage
Polyester staple fiber needle-punched geotextile has good water conductivity, it can form drainage channels inside the soil,
The remaining liquid and gas are discharged.
4: Reinforcement
The use of polyester staple fiber needle-punched geotextile to enhance the tensile strength and anti-deformation ability of the soil, enhance the stability of the building structure, and improve the stability of the building structure.
Good soil quality.
5: Protection
When the water flow scours the soil, it effectively spreads, transmits or decomposes the concentrated stress, prevents the soil from being damaged by external forces, and protects the soil.
6: Anti-puncture
Combined with geomembrane, it becomes a composite waterproof and anti-seepage material, which plays the role of anti-puncture.
High tensile strength, good permeability, air permeability, high temperature resistance, freezing resistance, aging resistance, corrosion resistance, no moth-eaten.
Polyester staple fiber needle-punched geotextile is a widely used geosynthetic material. Widely used in the reinforcement of railway subgrade and road pavement
Maintenance of sports halls, protection of dams, isolation of hydraulic structures, tunnels, coastal mudflats, reclamation, environmental protection and other projects.
Features
Light weight, low cost, corrosion resistance, excellent performance such as anti-filtration, drainage, isolation and reinforcement.
Use
Widely used in water conservancy, electric power, mine, highway and railway and other geotechnical engineering:
l. Filter material for soil layer separation;
2. Drainage materials for mineral processing in reservoirs and mines, and drainage materials for high-rise building foundations;
3. Anti-scour materials for river dams and slope protection;
4. Reinforcing materials for railways, highways, and airport runways, and for road construction in swampy areas;
5. Anti-frost and anti-freeze thermal insulation materials;
6. Anti-cracking material for asphalt pavement.
Application of geotextile in construction
(1) Used as reinforcement in backfilling of retaining walls, or as panels for anchoring retaining walls. Construction of wrapped retaining walls or abutments.
(2) Reinforce the flexible pavement, repair the cracks on the road, and prevent the pavement from reflecting cracks.
(3) Increase the stability of gravel slopes and reinforced soil to prevent soil erosion and freezing damage of soil at low temperatures.
(4) The isolation layer between the road ballast and the subgrade, or the isolation layer between the subgrade and the soft subgrade.
(5) The isolation layer between artificial fill, rockfill or material field and foundation, and isolation between different permafrost layers. Anti-filtration and reinforcement.
(6) The filter layer of the upstream dam surface in the initial stage of the ash storage dam or tailings dam, and the filter layer of the drainage system in the backfill of the retaining wall.
(7) The filter layer around the drainage underdrain or around the gravel drainage underdrain.
(8) The filter layer of water wells, pressure relief wells or oblique pipes in water conservancy projects.
(9) Geotextile isolation layer between roads, airports, railway tracks and artificial rockfills and foundations.
(10) Vertical or horizontal drainage inside the earth dam, buried in the soil to dissipate pore water pressure.
(11) Drainage behind the anti-seepage geomembrane in earth dams or earth embankments or under the concrete cover.
(12) Eliminate the seepage around the tunnel, reduce the external water pressure on the lining and seepage around the buildings.
(13) Drainage of artificial ground foundation sports ground.
(14) Roads (including temporary roads), railways, embankments, earth-rock dams, airports, sports fields and other projects are used to strengthen weak foundations.
Laying of geotextiles
Filament geotextile construction site
Geotextile rolls should be protected from damage before installation and deployment. Geotextile rolls should be stacked in a place that is leveled and free from water accumulation, and the stacking height should not exceed the height of four rolls, and the identification sheet of the roll can be seen. Geotextile rolls must be covered with opaque material to prevent UV aging. During storage, keep labels intact and data intact. Geotextile rolls must be protected from damage during transport (including on-site transport from material storage to work).
Physically damaged geotextile rolls must be repaired. Severely worn geotextiles cannot be used. Any geotextiles that come into contact with leaked chemical reagents are not allowed to be used in this project.
How to lay the geotextile:
1. For manual rolling, the surface of the cloth should be flat, and a proper deformation allowance should be reserved.
2. The installation of filament or short filament geotextiles usually uses several methods of lap jointing, sewing and welding. The width of stitching and welding is generally more than 0.1m, and the width of lap joint is generally more than 0.2m. Geotextiles that may be exposed for a long time should be welded or sewn.
3. Sewing of geotextile:
All stitching must be continuous (eg, point stitching is not allowed). Geotextiles must overlap at least 150mm before overlapping. The minimum stitching distance is at least 25mm from the selvedge (the exposed edge of the material).
Sewn geotextile seams at most include 1 row of wired lock chain seams. The thread used for stitching should be a resin material with a minimum tension exceeding 60N, and have chemical resistance and ultraviolet resistance equivalent to or exceeding that of geotextiles.
Any "missing stitches" in the sewn geotextile must be resewn in the affected area.
Appropriate measures must be taken to prevent soil, particulate matter or foreign matter from entering the geotextile layer after installation.
The lap of cloth can be divided into natural lap, seam or welding according to the terrain and function of use.
4. During the construction, the geotextile above the geomembrane adopts natural lap joint, and the geotextile on the upper layer of the geomembrane adopts seaming or hot air welding. Hot air welding is the preferred connection method of filament geotextiles, that is, use a hot air gun to instantly heat the connection of two pieces of cloth to a melting state, and immediately use a certain external force to firmly bond them together. . In the case of wet (rainy and snowy) weather where thermal bonding cannot be performed, another method for geotextiles - stitching method, is to use a special sewing machine for double-thread stitching, and use chemical UV-resistant sutures.
The minimum width is 10cm during sewing, 20cm during natural overlap, and 20cm during hot air welding.
5. For the stitching, the suture thread of the same quality as the geotextile should be used, and the suture thread should be made of a material with stronger resistance to chemical damage and ultraviolet light irradiation.
6. After the geotextile is laid, the geomembrane shall be laid after the approval of the on-site supervision engineer.
7. The geotextile on the geomembrane is laid as above after the geomembrane is approved by Party A and the supervisor.
8. The numbers of the geotextiles of each layer are TN and BN.
9. The two layers of geotextile above and below the membrane should be embedded in the anchoring groove together with the geomembrane at the part with the anchoring groove.
Basic requirements for laying geotextiles:
1. The joint must intersect with the slope line; where it is balanced with the slope foot or where there may be stress, the distance between the horizontal joint must 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 is kept in a taut state.
3. All geotextiles must be pressed with sand bags. The sand bags will be used during the laying period and will be retained until the top layer of material is laid.
Geotextile laying process requirements:
1. Grass-roots inspection: Check whether the grass-roots level is smooth and solid. If there is any foreign matter, it should be handled properly.
2. Trial laying: Determine the size of the geotextile according to the site conditions, and try laying it after cutting. The cutting size should be accurate.
3. Check whether the width of the salad is appropriate, the lap joint should be flat, and the tightness should be moderate.
4. Positioning: Use a hot air gun to bond the overlapping parts of the two geotextiles, and the distance between the bonding points should be appropriate.
5. The sutures should be straight and the stitches should be uniform when stitching the overlapping parts.
6. After sewing, check whether the geotextile is laid flat and whether there are defects.
7. If there is any unsatisfactory phenomenon, it should be repaired in time.
Self-check and repair:
a. All geotextiles and seams must be checked. Defective geotextile pieces and seams must be clearly marked on the geotextile and repaired.
b. The worn geotextile must be repaired by laying and thermally connecting small pieces of geotextile, which are at least 200mm longer in all directions than the edge of the defect. The thermal connection must be strictly controlled to ensure that the geotextile patch and the geotextile are tightly bonded without damage to the geotextile.
c. Before the end of each day's laying, conduct a visual inspection on the surface of all the geotextiles laid on the day to confirm that all damaged places have been marked and repaired immediately, and make sure that the laying surface is free from foreign substances that may cause damage, such as fine needles, small iron Nail etc.
d. The following technical requirements should be met when the geotextile is damaged and repaired:
e. The patch material used to fill holes or cracks should be the same as the geotextile.
f. The patch should extend at least 30 cm beyond the damaged geotextile.
g. At the bottom of the landfill, if the crack of the geotextile exceeds 10% of the width of the coil, the damaged part must be cut off, and then the two geotextiles are connected; if the crack exceeds 10% of the width of the coil on the slope, it must be Remove the roll and replace with a new roll.
h. The work shoes and construction equipment used by the construction personnel should not damage the geotextile, and the construction personnel should not do anything on the laid geotextile that may damage the geotextile, such as smoking or poking the geotextile with sharp tools.
i. For the safety of geotextile materials, the packaging film should be opened before laying geotextiles, that is, one roll is laid and one roll is opened. And check the appearance quality.
j. Special proposal: After the geotextile arrives at the site, the acceptance and visa verification should be carried out in time.
It is necessary to strictly implement the company's "Geotextile Construction and Acceptance Regulations"
Precautions for installation and construction of geotextiles:
1. The geotextile can only be cut with a geotextile knife (hook knife). If it is cut in the field, special protection measures must be taken for other materials to prevent unnecessary damage to the geotextile due to cutting;
2. When laying geotextiles, all necessary measures must be taken to prevent damage to the material below;
3. When laying geotextiles, care must be taken not to let stones, a large amount of dust or moisture, etc., that may damage the geotextiles, may block drains or filters, or may cause difficulties for subsequent connections into the geotextiles. or under the geotextile;
4. After installation, conduct visual inspection on all geotextile surfaces to determine all damaged landowners, mark and repair them, and make sure that there are no foreign substances that can cause damage on the paved surface, such as broken needles and other foreign objects;
5. The connection of geotextiles must follow the following regulations: under normal circumstances, there should be no horizontal connection on the slope (the connection must not intersect with the contour of the slope), except for the repaired place.
6. If suture is used, the suture must be made of the same or more than the material of the geotextile, and the suture must be made of anti-ultraviolet material. There should be obvious color difference between the suture and the geotextile for easy inspection.
7. Pay special attention to the stitching during installation to ensure that no dirt or gravel from the gravel cover enters the middle of the geotextile.
Geotextile damage and repair:
1. At the suture junction, it is necessary to re-suture and repair, and make sure that the end of the skip stitch has been re-sutured.
2. In all areas, except for rock slopes, leaks or torn parts must be repaired and stitched with geotextile patches of the same material.
3. At the bottom of the landfill, if the length of the crack exceeds 10% of the width of the coil, the damaged part must be cut off, and then the two parts of the geotextile are connected.
Post time: Sep-22-2022