The leakage and pollution of the landfill site pose a huge threat to the environment. After soil pollution, it will become saline alkali and parasitic in the soil. Infiltration can also contaminate groundwater and enter the human food chain, causing serious harm to the environment. Since the 1960s, high-density polyethylene (HDPE) geomembranes with a thickness of 1-2 millimeters have been used for anti-seepage treatment in landfills abroad. Currently, it has become a mature technology and is being increasingly applied. China's landfill started relatively late, but in recent years, with the attention of our country and the improvement of national environmental protection awareness, landfill sites treated with geomembranes have been widely used throughout the country.
Landfilling is generally carried out using mountain valleys, excavated mines, etc. for anti-seepage. The anti-seepage layer of the landfill site is usually filled with thousands of tons of garbage, so a anti-seepage membrane with a thickness of 1.5mm or more is generally used, and the width should be greater than 6 meters to reduce welding joints. Because practice has proven that leakage in landfills mostly occurs at welding joints. A rough anti-seepage membrane can be used on the slope to increase the friction coefficient and maximize the available volume.
1. Roll, clean and level the surface to be laid, dig blind ditches, and lay exhaust and drainage pipes. More specific grassroots treatment can be handled according to design requirements.
2. After laying the geotechnical protection liner, HDPE anti-seepage geomembrane can be laid. Prepare sandbags and other heavy objects, compact the laid HDPE anti-seepage geomembrane, and prevent the wind from blowing. When laying, welding joints should be minimized as much as possible, and a suitable laying plan should be selected according to the actual site size.
Before welding, conduct a trial welding and select appropriate welding parameters based on the weather of the day. When welding, professional welding equipment should be used, using a double track hot melt automatic crawling welding machine; The welding and scar repair of T-shaped and cross shaped structures should be carried out using a hot melt extrusion welding machine.
4. For steep slope welding, rope ladders or scaffolding can be used. Welding machine technicians need to take safety measures.