一. Construction preparation
1、Grass-level treatment
Before laying the geocomposite drainage network, the base layer should be thoroughly cleaned to ensure that there are no hard protrusions such as gravel and blocks on the surface, and the flatness and compaction required by the design should be met. The flatness shall not be greater than 15 mm， The compaction degree should meet the engineering design standards. The surface of the base layer should also be kept dry to avoid the influence of moisture on the performance of the drainage net.
2、Material inspection
Before construction, the geocomposite drainage network should be comprehensively inspected to ensure that it is not damaged or polluted, and it also meets the design requirements. Special attention should be paid to checking the core part of the drainage net to ensure that its three-dimensional structure is complete and free from deformation or damage.
3、Environmental Conditions
When laying the geocomposite drainage network, the outdoor temperature should be 5 ℃It can be carried out under weather conditions above, wind force below level 4, and no rain or snow, so as to ensure the construction quality.
二. Laying specifications
1、Laying direction
Geocomposite drainage networks must be laid down the slope, ensuring that the length direction is along the direction of water flow. For some long and steep slopes, special attention should be paid to using a complete length of material roll at the top of the slope to avoid affecting the drainage effect due to cutting.
2、Obstacle handling
When encountering obstacles during laying, such as discharge pipes or monitoring wells, cut the drainage net and lay around the obstacles to ensure that there is no gap between the obstacles and the materials. When cutting, the lower geotextile and geonet core of the composite drainage net should come into contact with obstacles, and the upper geotextile should have enough margin, so that it can be folded back under the drainage net to protect the exposed geonet core.
3、Laying requirements
When laying, the drainage net should be straightened and smooth, close to the base layer, and there should be no distortion, wrinkle or heavy Stack Phenomenon. The adjacent edge overlapping portion in the length direction of the composite drainage network is at least 100 mm， Also use HDPE Plastic belt binding, the binding belt should be located at the heavy Stack The shaft of at least one geonet is intermediate of the portion and passes through the shaft of the at least one geonet. The joint binding spacing along the side slope is 150 mm， The binding spacing between the joints at both ends of the anchoring trench and the bottom of the landfill is also 150 mm。
三. Overlapping specifications
1、Lap joint method
When the geocomposite drainage net is overlapped, plastic fasteners or polymer materials should be used to connect, and metal belts or metal fasteners should not be used. The color of the overlap should be white or yellow to facilitate inspection. For upper geotextile, minimum weight Stack 150 mm； The lower geotextile needs to be completely overlapped, and the upper geotextile can be fixed together by sewing or welding. At least one row of double-thread needles shall be used at the joint, the sewing thread shall be multi-strand, and the minimum tension shall not be less than 60 N， It must also have chemical corrosion and ultraviolet resistance comparable to geotextiles.
2、Overlap detail
During the overlapping process, special attention should be paid to the sealing of the overlapping part to prevent moisture or fine particles from entering the drainage mesh core. Thermal bonding method, the temperature should be strictly controlled to avoid burning through the geotextile. All overlapping parts should be carefully checked to ensure that there is no “missing stitch” phenomenon, and if any is found, the seams should be mended in time.
四. Backfilling and compaction
1、Backfill material
After the drainage network is laid, backfilling treatment should be carried out in time. Backfill materials should be made of well-graded gravel or sand, and avoid using large stones to avoid damaging the drainage net. Backfilling should be carried out from both sides at the same time to avoid the deformation of the drainage network caused by unilateral loading.
2、Compaction requirements
The backfill material should be compacted in layers, and the thickness of each layer should not exceed 30 cm。 During compaction, light mechanical or manual methods should be used to avoid excessive pressure on the drainage network. The compacted backfill layer should meet the density and flatness required by the design.
五. Acceptance and maintenance
1、Acceptance criteria
After the construction is completed, the laying quality of geocomposite drainage network should be comprehensively accepted. The acceptance contents include but are not limited to: the laying direction of the drainage network, the overlap quality, the compactness and flatness of the backfill layer, etc. Also check that the drainage system is unobstructed and ensure that the drainage effect is achieving the desired goal.
2、Maintenance and inspection
During use, the geocomposite drainage network should be inspected and maintained regularly. The inspection contents include the integrity of the drainage net, the tightness of the overlapping parts and the drainage effect. If problems are found, they should be dealt with in time to avoid affecting the stability and durability of the engineering structure.
As can be seen from the above, only the correct laying Geocomposite drainage net can ensure its full performance. From construction preparation to laying, overlap, backfilling and acceptance, all aspects must strictly abide by the specification requirements to ensure that every process meets the design requirements. Only in this way can the drainage performance of geocomposite drainage network be fully exerted and the stability and durability of engineering structure be improved.
Post time: Mar-14-2025
