To provide a technology for forming a space in the ground by which a need for conveying the earth from the original position to the ground surface is eliminated and slurry is not generated when various kinds of underground consolidation bodies like a pile or an underground continuous wall are built.

The ground widening method includes an insertion process in which a ground widening device (1) comprising a rigid member (2) and a bag-like member (pressure vessel 3) capable of expanding and contracting is inserted into a predetermined position of the construction ground (G), an expansion process for pressing the ground (G) around the ground widening device (1) by supplying a fluid (F) for expansion into the bag-like member (3) to expand it, and a contraction process in which the fluid (F) for expansion is discharged from the bag-like member(3) to contract it.

COPYRIGHT: (C)2008,JPO&INPIT