STRUCTURE OF UNDERGROUND TANK AND BUILDING METHOD THEREOF

摘要

PROBLEM TO BE SOLVED: To provide a structure of an underground tank and a building method thereof for reducing the thickness of a rubble layer and also reducing the pumping volume. SOLUTION: A lower drain rubble layer 3 is formed on an excavation floor forming face, and a shielding layer 5 is formed on the lower drain rubble layer 3, and an upper drain rubble layer 6 is formed on the shielding layer 5. The drain rubble layer is connected with a pumping pit 4 by a drain pipe. A tank bottom plate is provided on an upper drain layer 6.