The use of natural gas as a source of energy has been boosted around the world. In fact, a great number of LNG processing and storage plants are been designed and built in recent years. For instance, the Ras Laffan plant, built by the Japanese company IHI.

This deposit has a LNG storage capacity of 140,000 m3 at -165ºC. The external tank is made of structural concrete and has a 76m inner diameter. It is 38.10 m high and it has a concrete dome.

Since it is located in a high/normal risk seismic area, structures are analysed and sized taking this into account. Therefore, foundation is composed of Ø 1m piles which are 40m deep and embedded in the slab: 383 piles at a depth of 9.5m.

Some of the most significant features of these structures are: a monolithic joint of the foundation piles to the bottom slab with a constant thickness of 0.80 and 1.15m; the fact that the 0.80 m thick perimeter wall is embedded into the bottom slab; postensioning by means of horizontal and vertical cables of the perimeter wall and a reinforced concrete dome with minimum thickness of 0.40m embedded in the ring that culminates the perimeter wall with two-layered concrete.