PURPOSE: To make easier the adjustment of level of a structure when non-uniform subsidence occurs by a method in which a reinforced concrete bottom slab is buried in the ground, dry sand is placed on the bottom slab, and a cylindrical steel tube to support the structure through a support plate is rigidly connected to the bottom slab in such a way as to enable the sand to be freely discharged.

CONSTITUTION: A reinforced concrete bottom slab 11 is buried in the ground 12, and a cylindrical steel tube 14 whose lower end is closed and the upper end is opened is rigidly connected to the upside of the bottom slab 11. Dry sand 15 is packed into the steel tube 14, and a presser plate 16 is placed on the sand 15. Plural sand discharge ports 17 are drilled in the steel tube 14 above the ground's surface, and the diameter of the ports 17 is such as not to naturally flow out the sand 15 but to enable the sand 15 to be forcibly discharged by insertion of a bar-like object. The regulation of the level of a structure can thus be easily made when non-uniform subsidence of the ground occurs.