CONSTRUCTION METHOD FOR COMPLETELY BURIED UNDERGROUND TANK

PURPOSE:To shorten the term of construction of a completely buried underground tank for storing a low temperature liquefied gas by assembling the ceiling section of an inner tank with a cold insulator lined up within a concrete outer tank constructed underground, concurrently fitting engaging members thereon for the ceiling section of the outer tank, and thereby lifting the ceiling section up so as to be fixed. CONSTITUTION:A hollow cylindrical concrete outer tank 1 is constructed underground. Assembling frames 5 are then installed in the inner bottom section 4 of the outer tank 1, an inner tank ceiling section 3 in an inner board shape is assembled thereafter with the membrane panels joined, which are split into each specified size. A cold insulator 6 is fitted onto the upper surface of the inner tank ceiling section 3, and rod shaped engaging members 7 are concurrently projected. Fixing sections 8 which accept and fix the engaging members 7, are bored in an outer tank ceiling section 2. The inner tank ceiling section 3 is then lifted so as to be transported to the outer tank ceiling section 2, so that the inner ceiling section 2 is fixed with the engaging members 7 engaged with the fixing sections 8. After that, cold reserving treatment and inner tank forming works for both the outer tank inner bottom section 4 and the inner wall 12 of a side section are processed, and the outer tank 1 is then covered with soil.