Better landfill engineering in Shenzen with NAUE
Location of work/project:
China – Shenzen – Hong Hua Ling Landfill
Shenzhen’s rapid industrial and residential growth has created numerous environmental quality challenges. The Hong Hua Ling has operated for years, accepting many types of waste streams, including types of wastes considered more sensitive (e.g., medical wastes). To correct this old approach, a modern expansion was called for.
The subsequent 140,000m² expansion design has enabled the site to handle nearly half of the total waste disposal of Shenzhen’s Longgang area, including accepting 1,600 tonnes of waste daily.
The expanded area’s lining system was initially designed with a double-lined base, but geological analysis found that an existing clay layer of 2.3m – 5.9m with low permeability could act as a secondary barrier. The primary liner, though, needed to be a high-quality geosynthetic solution. HDPE geomembrane was specified, with 1.5mm and 2.0mm thick geomembranes selected for use in various zones.
Carbofol® HDPE geomembranes were utilized throughout the site. At the base, a smooth Carbofol ® liner was selected while an embossed, structured surface Carbofol® geomembrane was chosen for the sloped areas over co-extruded or sprayed-on structured surface geomembrane. The advantages of interface friction performance is i.a. due to structure and homogeneousness of the membrane surface.
The use of this HDPE geomembrane also provided the operational and construction benefits that the design engineering team wanted: high stress crack resistance, a high Melt Flow Rate to enable strong welding performance, excellent chemical resistance, etc. Drainage netting was used as the leak detection layer and as a drainage layer below the aggregate. These drainage layers also have a dual function of protecting the Carbofol® HDPE geomembrane from potential puncture damage. Additional protection was provided by a robust geotextile layer situated between the HDPE geomembrane and the thick clay subgrade. The construction works at the Hong Hua Ling Landfill were executed on a very tight schedule, due to the pressure for the fast-growing area to have the massive expansion in operation as soon as possible.