How to construct geomembrane?

　　Improper construction can lead to the incomplete functioning of geosynthetics, and careful construction is an important link to ensure that geosynthetic engineering works well. Below is an effective construction plan to ensure the smooth completion of the construction.

　　1、 Site foundation treatment

　　1. Before laying HDPE geomembrane, a comprehensive inspection of the laying base should be carried out in conjunction with relevant departments. The laying base should be solid and flat, and there should be no tree roots, debris, stones, concrete particles, steel reinforcement heads, glass chips, or other debris that may damage the geomembrane within a vertical depth of 25mm. Use a wheel compactor to compact to remove car marks, footprints, and uneven ground surfaces. In addition, ground protrusions larger than 12mm should also be chipped or compacted.

　　2. When HDPE geomembrane is laid on the backfill soil, the compaction degree of the backfill soil should not be less than 95%.

　　3. The site foundation should be free of seepage, silt, accumulated water, organic residue, and harmful substances that may cause environmental pollution. The corner of the foundation should be smooth, and in general, its arc radius should not be less than 500 millimeters.

　　2、 Technical requirements for construction of HDPE geomembrane.

　　1. The laying and welding of HDPE geomembrane should be carried out at temperatures above 5 ℃, with wind speeds below level 4 and no rain or snow.

　　2. The construction process of HDPE geomembrane is carried out in the following order: geomembrane laying - aligning welding joints - welding - on-site inspection - repair - re inspection - backfilling soil.

　　3. The overlapping width of the joint between the membrane should not be less than 80 millimeters, and the joint arrangement direction should generally be equal to the slope line, that is, arranged along the slope direction.

　　4. During the laying of HDPE geomembrane, artificial wrinkles should be avoided as much as possible. When laying HDPE geomembrane, the expansion and contraction deformation caused by temperature changes should be reserved according to the local temperature change amplitude and the performance requirements of HDPE geomembrane. In addition, the expansion and contraction amount of geomembrane should be reserved according to the site terrain and the situation of geomembrane laying to adapt to uneven settlement of the foundation.

　　5. After the laying of HDPE geomembrane, it is necessary to minimize walking on the membrane surface, handling tools, etc. Any objects that can cause harm to the HDPE geomembrane should not be placed or carried on the geomembrane to avoid accidental damage to the HDPE membrane.

　　6. All personnel on the HDPE membrane construction site are not allowed to smoke, wear shoes with iron nails or high heels and hard soles to walk on the membrane surface, and are not allowed to engage in any activities that may damage the anti-seepage membrane.

　　7. After the laying of HDPE geomembrane and before covering the protective layer, one 20-40kg sandbag should be placed every 2-5m at the edges and corners of the membrane to prevent the geomembrane from being blown up by the wind.

　　8. HDPE geomembrane should be natural and closely attached to the support layer, without folding or hanging.

　　9. During the segmented construction of geomembrane, the upper layer should be covered in a timely manner after laying, and the exposure time in the air should not exceed 30 days.