NATURAL GROUND REINFORCING METHOD AND NATURAL GROUND REINFORCING MATERIAL USED FOR IT

PROBLEM TO BE SOLVED: To provide a natural ground reinforcing method and a natural ground reinforcing material used for a tunnel prefabricated form method and capable of satisfactorily reinforcing the natural ground without releasing an injected chemical even in the natural ground where opening cracks are developed. SOLUTION: A hollow tubular core material 1 having discharge holes 1a at many places in the axial direction is inserted into a bore hole H formed on a base rock or the like, and a consolidating chemical M is injected into the bore hole H and the natural ground around it via the hollow tubular core material 1 and is consolidated to reinforce the natural ground in this natural ground reinforcing method. Bulkheads are formed near both end sections in the axial direction of the core material 1 inserted into the bore hole H, and the outer periphery of the core material 1 between both bulkheads is covered with a liquid-permeable tube body 4 through which the consolidating chemical M can flow. The consolidating chemical M flowing into the core material 1 flows into the tube body 4 from the discharge holes 1a then flows into the bore hole H and the natural ground around it and is consolidated.