As for the LNG above ground storage tanks constructed in countries other than Japan, their mechanical and civil structures are more different than Japanese ones in various points because of the differences in the codes, standards, regional environment and safety criteria.
We explain and introduce the approach to the peculiar structure, loading condition and design method (FEM analysis) that have been adopted to the tanks in the other countries by IHI up to now. In addition, a new construction technique and the features are introduced.

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The main stream of above ground LNG storage tank in abroad is a full containment tank, which shall consist of a primary container with 9 % Ni Steel and a secondary container, which is made up of foundation (piles) , RC slab, PC wall and RC roof. EN14620 (Euro code) or BS7777 (British Standard) provides a conception of secondary container, selection of structure types and design requirements. In this commentary, the design requirements and their actual performances will be explained through our executing EPC (Engineering, Procurement and Construction) projects, comparing the differences with above ground tanks in Japan.
Besides, some distinctive construction works and recent approach in tank construction will be explained also.

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On June 5, 2009, there was an oil leakage failure accident from an above ground oil storage tank in a large oil depot. The pump of the tank was broken, therefore, the oil contained in the pipeline leaked. The leaked oil amounted to 35, 000L.
The authors have investigated the tank, the pump and the pipeline to find the cause of the accident and to suggest a preventive measure against same kind of accidents. Some important issues of the investigation are fractography examination of a part on which failure occurred, strength of the pump and a type of load and its magnitude which produced during the operation. As a result, the authors have found that the accident was caused because of an excessive internal pressure rise in the pipeline because the pressure relief valve had been removed from the tank due to an improper piping work. Also the authors have estimated that the internal pressure could reach up to 5. 49MPa, and then the pressure caused the brittle fracture of the pump casing.

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The single-deck floating roofs are used in large aboveground oil storage tanks. The deck plates of the roofs have 4. 5mm in thickness and are joined by continuous full-fillet welds on the upper side of lap plates. The deck plates are subjected to cyclic bending deformation due to wind load. This may lead to fatigue cracks at the lap welded joints. The cracks continue to grow in long time period. The oil will be spilled on the welded joints of the deck plates when the cracks penetrate. In this paper, the crack growth of the surface cracks in the lap joints is described. The stress intensity factors are analyzed using the Influence Function Method established by Shiratori, and the crack growth is based on the Paris law. The stress analysis of the virtual cracked surface in the uncracked lap welded joint is performed by the plane strain elastic FEA. The relations between the load amplitude and the fatigue life of crack penetration are obtained.

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