Geocomposite drainage layer: also known as 3D composite drainage board, tunnel drainage board. It is composed of a three-dimensional plastic mesh with double-sided bonding water seepage geotextiles, which can replace the traditional sand and gravel layers, and is mainly used for drainage of landfills, roadbeds and inner walls of tunnels.
The main performance and indicators of Geocomposite drainage layer：
1. When the load is 720kPa and the gradient is 2%, the permeability is 2500m/d and the flow rate is 13pm/m.
2. The creep test retains more than 60% of the thickness after bearing a load of 1200kPa for 10,000 hours.
3. The carbon black content of the three-dimensional drainage mesh core is not less than 2%, the density is 0.94g/cm3, the tensile strength is not less than 36.5kN/m, the melt index is 1.0g/10min, and the thickness is 7.6mm.
4. The water permeability of non-woven geotextile is 0.26 Sec-1.
Geocomposite drainage layer application：
1. Lay it between the foundation and the base to drain the water between the foundation and the base.
2. Laying a three-dimensional composite drainage network on the sub-base can prevent the fine materials of the sub-base from entering the sub-base (that is, it plays a role in isolation). The aggregate base layer will enter the upper part of the geonet to a limited extent. It also has the potential to limit the lateral movement of the aggregate base, in this way it acts like the reinforcement of a geogrid. Generally speaking, the tensile strength and rigidity of the three-dimensional composite drainage net are better than that of many geogrids used for foundation reinforcement, and this restriction will improve the support capacity of the foundation.
3. After the road is aging and cracks are formed, most of the rainwater will enter the section. In this case, the three-dimensional composite drainage net is laid directly under the road surface instead of the drainable foundation. The three-dimensional composite drainage mesh can collect moisture before it enters the foundation/subbase. Moreover, the bottom end of the three-dimensional composite drainage net can be wrapped with a layer of film to further prevent moisture from entering the foundation. This structure can prolong the service life of the road.
Geocomposite drainage layer construction guidance:
The order of laying geotechnical materials in irregular landfills and regular landfills is the same. First, the soil base should be cleaned, leveled and compacted, followed by the laying of GCL, and anti-seepage geomembrane. After the laying is completed, the Geocomposite drainage layer is laid immediately, and it is rolled manually. The overlapping connection between the Geocomposite drainage layer is connected with plastic tapes or plastic buttons, and the buttons are connected every 90 cm to 1 meter. Then lay a layer of geomembrane and geotextile on the drainage net in turn, then landfill the garbage, then lay a layer of anti-seepage geomembrane to cover, then backfill with soil of no less than 30 cm, and finally fill in nutrient soil and plant trees to restore it. Green surroundings.