Method and apparatus for lifting, leveling, amd underpinning a building foundation

A method for lifting and underpinning a building foundation comprising the steps of:

• a) excavating at least one cavity below the perimeter of a building foundation;
• b) inserting a screw anchor having an extendable shaft portion and an auger portion at an angle of approximately 15 degrees relative to the outer vertical edge of the building foundation to a sufficient depth to insure stability and extending said anchor as necessary to reach the surface of the foundation;
• c) filling at least a portion of said cavity with dry cement mix forming a bed therein;
• d) providing and installing a first base plate assembly comprising a base plate, a tubular collar, slidable upon said shaft portion, attached perpendicular to one edge of said first base plate;
• and a gusset plate attached perpendicular to said first base plate and said tubular collar at vertical angle of approximately 15 degrees and in such a manner that said gusset plate is pressed into said cement mix and said base plate rests on the surface of said bed;
• e) providing a second base plate parallel to and in contact with said first base plate;
• f) installing at least one hydraulic jack vertically between said second base plate and said foundation;
• g) actuating said hydraulic jack;
• thereby lifting said foundation to near level plane;
• h) providing and installing a screw jack adjacent said hydraulic jack and adjusting said screw jack to take the full load of said hydraulic jack and removing said hydraulic jack;
• i) wetting said cement mix sufficiently to form a cement pier;
• and
• j) welding said collar to said screw anchor and removing any excess portion of said shaft.