GROUND IMPROVEMENT METHOD

PROBLEM TO BE SOLVED: To provide a ground improvement method wherein effect by intermittent supplying is further enhanced and thereby the ground can be positively compacted. SOLUTION: With regard to the improvement method of the ground, a supply pipe 20 of compressed air and a suction pipe 22 of underground water and the air are inserted in sandy ground 24. The compressed air is intermittently supplied to the sandy ground 24 through the supply pipe 20, and impact load is applied to the sandy ground 24. The underground water and the air are sucked from the sandy ground 24 through the suction pipe 22 successively during supplying of the compressed air or after supply stop of the compressed air.