GROUND IMPROVEMENT METHOD BY VACUUM CONSOLIDATION OF SOFT GROUND HAVING SAND LAYER IN INTERMEDIATE DEPTH POSITION

摘要

PROBLEM TO BE SOLVED: To provide a ground improvement method by vacuum consolidation of the soft ground effectively carrying out the soft ground improvement by vacuum consolidation making use of a vertical drainage material for the soft ground having a sand layer in an intermediate depth position. SOLUTION: A water permeable vertical drainage material 2 having an air impermeable section 15a cutting off vent from the circumferential surface to a height position corresponding to the height of the intermediate depth position in an intermediate height of the soft ground 1 in advance is inserted into the soft ground, and the inside of the vertical drainage material 2 is decompressed by a decompression means to consolidate the soft ground by vacuum pressure and, at the same time, water in the soft ground is made to flow inside of the vertical drainage material to discharge.