Buffer material applying method and device

A powdery buffer material which can be solidified under pressure is charged into a disposing hole, an expandable/shrinkable hydraulic bag is inserted to the powdery buffer material, and then highly pressurized water is injected to expand the hydraulic bag and the powdery buffer material is urged to the inner wall surface of the disposing hole by expansion pressure to solidify and form a solid buffer material. Namely, a movable truck main body comprises a means for elevating an elevating plate so as to open/close an opening, an expandable/shrinkable hydraulic bag disposed to the lower surface of the elevating plate and a highly pressurized water-injection means for injecting highly pressurized water into the hydraulic bag. The buffer material is thus manufactured and applied simultaneously by transporting the heavy weighted buffer material in the form of a powder to a site and press-molding it in the disposing hole thereby capable of reducing the time, labor and cost required for transporting operation remarkably. (N.H.)