Soft ground improvement equipment and soft ground improvement method

摘要

PROBLEM TO BE SOLVED: To provide an improvement device of a weak ground and an improvement method of a weak ground which prevent air in the outside of an airtight sheet from flowing in a drain passage to reduce a differential pressure between a negative pressure in the inside of the airtight sheet and an atmospheric pressure, and thereby improve a water absorption effect from each drain material and can improve an effect of ground improvement.SOLUTION: An improvement device includes: a plurality of members 5 for vertical drainage arranged in a vertical direction inside of a ground 3 as an improvement object; a plurality of members 7 for horizontal drainage which are arranged on a surface 3a of the ground in a horizontal direction and are connected to the members 5 for vertical drainage so as to delivery and receive water; an airtight sheet 11 which is laid so as to cover the surface 3a of the ground together with the members 7 for horizontal drainage and where a peripheral edge portion 11a is embedded along the peripheral edge portion of the ground 3 in the ground 3 to a predetermined depth; a vacuum pump 21 for drain connected to the members 7 for horizontal drainage; a member 17 for air suction arranged along the peripheral edge portion 11a of the airtight sheet 11; and a vacuum pump 25 for air suction connected to the members 17 for air suction.SELECTED DRAWING: Figure 1