Patent ID: 8678712

Claim:
A method for forming a movable slab foundation, the method comprising: (a) placing a plurality of support surfaces below an intended slab foundation area; (b) placing a plurality of support sleeves in abutting contact with the plurality of support surfaces, each of the support sleeves having a side wall containing a plurality of lift holes therethrough; (c) placing a column within each of the support sleeves into abutting contact with one of the support surfaces, each of the plurality of column members surrounded by an engagement device comprising: a chuck body rigidly connected to one of the support sleeves, the chuck body having a tapered inner surface that extends downwardly and outwardly away from the column, the lower end of the tapered inner surface extending inward and forming a substantially upward facing shoulder; and a shim in the chuck body and having a tapered outer surface substantially geometrically complimentary to the inner surface of the chuck body, the tapered outer surface extending downwardly and outwardly from the column, the lower end of the tapered outer surface having a downward facing surface, the shim having an inner surface adjacent to the column; (d) forming a slab foundation such that it encases the support sleeves; (e) providing a plurality of hydraulic jacks, each having a lift plate on an upper end and a plurality of attachments rods connected to and extending downward from the lift plate; (f) mounting each of the hydraulic jacks to an upper portion of one of the columns and inserting lower portions of the attachment rods into the lifting holes of the support sleeves; (g) actuating the hydraulic jacks to move the lift plates and attachment rods upward, thereby lifting the support sleeves so that the upward facing shoulders of the chuck bodies contact the downward facing surfaces of the shims and the engagement devices move upward relative to the support surfaces, and so that the slab foundation moves along lengths of the columns to a desired height; and (h) then, with the hydraulic jacks, lowering the support sleeves relative to the shims until the tapered inner surfaces of the chuck bodies engage the tapered outer surfaces of the shims, thereby applying an inward radial force to the shims that causes the inner surfaces of the shims to move radially inward and lock against the columns, transferring a weight of the slab foundation to the columns.