Abstract: Agitation shafts provided with agitation vanes at lower portions thereof are fastened rotatably to the outer circumferential surface of a support cylinder to form a soft ground hardening machine. Connecting means are provided between upper and lower portions of the support cylinder. The connect-means are adapted to be tensed and slackened for eliminating the inclination of the machine in operation. In a soft ground hardening method using this machine, the inclination thereof can be eliminated as the direction in which the machine is inserted into or withdrawn from the soft ground is measured momentarily.

Abstract: Agitation shafts provided with agitation vanes at lower portions thereof are fixed rotatably around a support cylinder to form a soft ground hardening machine. A direction control unit is provided at a lower portion of the support cylinder so as to control the direction in which the machine is inserted into and withdrawn from the soft ground. In a method of hardening the soft ground by using this machine, the direction in which the machine is inserted into and withdrawn from the soft ground is controlled as the direction in which the machine is being inserted into or withdrawn from the soft ground is measured.

Abstract: Consolidation construction for soft, unstable foundation for improving the bearing strength in order to fill earth thereon as in land reclaiming or to build structural construction thereon including dikes and roads. Examples of such unstable foundation requiring consolidation are: sea bottom with soft unsolid sedimentation heap as often referred to recently in Japan as HEDORO, muddy swamp land, layer of slimy industrial waste sludge of much water content and the like. Consolidation is effected on the spot by admixing hardening agent, such for instance as cement, with the slimy mud heap constituting the soft, unstable foundation.

Abstract: A plurality of agitation spindles are disposed, and an agitation vane is attached to the lower portion of each agitation spindle. A mixing and kneading zone for mixing and kneading soft soil with a hardener is formed so that the hardener is supplied near these agitation vanes. The agitation spindles are supported by reinforcing members and connecting members to construct a multiple spindle kneading apparatus for improving ground. In one embodiment, blade-like excavating cutters are mounted on the agitation spindles. In another embodiment, hollow agitation spindles are used and the hollow portions are used as hardener passages. In still another embodiment, a tube for injecting the hardener into the mixing and kneading zone is disposed so that it can be moved up and down. A method for hardening soft ground by using this multiple spindle kneading apparatus in which the hardener feed position can be changed is provided.

Abstract: This invention relates to a device for solidifying sludgy material depositing on the earth surface, the device comprising an agitator having intergrated agitating shafts, each of which is provided with agitating blades. The agitator is attached to a stern of a working barge with a certain angle of inclination and also provided with nozzles for injecting chemical hardener. The device is capable of effectively solidifying the surface sludge over a wide area.

Abstract: An apparatus for the solidification of sludges comprising an apparatus proper which can be moved in the vertical direction by lifting means and a casing surrounding the kneading zone of said apparatus proper and being capable of shifting in the vertical direction with respect to said apparatus proper. The apparatus proper includes agitating shafts driven and rotated by driving means and agitating blades attached to each agitating shaft to form the kneading zone. A hardener supply device is disposed in the kneading zone to feed a hardener to the kneading zone. The casing is arranged so that the sludge being treated is separated and partitioned from other sludge, and the vertical position of the casing can be changed so that a desirable treating condition is maintained in the sludge being treated.