Swedish furniture giant IKEA recently opened a 32,000sqm store on the outskirts of Doha. QEMS has installed a large water storage tank in which water from the surrounding area is collected, filtered and used for irrigation.
The tank is 42.4m long, 24.5m wide and 2.125m high with a capacity of 2,200 cubic metres. A special feature of this project is its support structure which comprises plastic support medium drain trenches that have been stacked directly in the 6m deep trench, on a 15cm thick sand layer and the lower part of the sealing process. The individual support media – 17,670 geotanks in total – are made of polypropylene and each is 740mm long by 400mm wide by 420mm tall (from AusDrain). They not only support the sealing system with the collected water but also the 3.7m thick excavation of sand and earth that was filled back in as well as the car park.
To ensure the integrity of the tank the sealing system comprises two layers that support the entire structure on six sides. A 350 g/sqm heavy geotextile was laid as an inner layer. The route layer comprises a 1mm-thick high-density polyethylene (HDPE) sealing sheet. The individual sheets were joined by using two Leister Comet hot-wedge automatic welding machines.