PURPOSE: To construct an underground structure in a short period without giving a constraint to the ground function of an existing facility.
CONSTITUTION: An artificial ground 10 constructed in advance on the excavation object ground face G is supported with jacks 20. The ground directly below the artificial ground 10 is excavated to the prescribed depth, the artificial ground 10 is lowered to the position of the support point of a continuous wall 35 provided at part of the excavated ground via the jacks 20, and the lining face 12 of the artificial ground 10 is set to the ground height nearly equal to the excavation object ground face G. The ground directly below the artificial ground 10 is excavated in succession, the ground face is lowered to the foundation ground of an underground structure, and an underground space is constructed. The underground structure is constructed in the underground space, and the artificial ground 10 is left at this place as a permanent structure.
SAKURA MASAMITSU
IKEDA TAKASHI
ONOUCHI KAZUHISA
