The use of natural gas as a source of energy is being promoted worldwide and at present a large number of processing and storage plants for natural gas are being built, including the Terminal Plant of Dahej and the Central Plant of Ras Laffan, built by the Japanese company IHI. The two tanks store liquefied natural gas at –165ºC, with a total capacity of 148,000 m3 in Dajeh and 140,000 m3 in Qatar. The concrete outer tanks have an internal diameter and minimum height of 81.80 and 37m respectively in Dajeh and 76.0 and 38.10m respectively in Qatar. They are crowned by a large concrete dome. The place where they are located is subject to high or normal seismic activity and the structures were analyzed and dimensioned taking this into account. The foundations were made with 578, 1m in diameter and 40 m deep, piles in Dajeh and 383, 9.5m deep, piles in Qatar, embedded in the slab. The most interesting aspects of these structures are: a monolithic joint of the foundation piles to the bottom slab, with a constant thickness of 1m in Dajeh (0.80 and 1.15m in Qatar); postensioning of the bottom slab using circumferential tendons (Dajeh); the fact that the 0.80m thick outer wall is embedded in the bottom slab; post-tensioning by horizontal and vertical cables of the outer wall, and a reinforced concrete dome of 0.40 minimum thickness embedded in the ring that culminates the outer wall, with two-layered concrete.
• Several views of the tanks in Dajeh during their construction. The size of this structure is shown in the dimensions of the most characteristic macro-units, which for the two tanks of Dajeh are: 40,000 m of 1000 mm piles, 30,000 m3 of structural concrete, 6,000 t of steel for reinforcement, partly of “cryogenic quality”, 10,000 t of steel for post-tensioning. • Tanks of Qatar in construction • Pictures of the calculation models
LIQUEFIED GAS TANKS IN DAJEH LNG, GUJARAT AND QATAR CONSTRUCTION PROJECTS India, 2001-2002. QATAR, 2003