US Patent 7931424 Apparatus and method for producing soil columns

A method and apparatus for constructing soil columns in-situ in the ground are disclosed for the purpose of improving the structure supporting capability of surface soils to support loads from buildings and other structures. Some embodiments use a surcharge ring or load to apply a stress to soil surrounding a construction site for a soil column. Methods according to the present disclosure may reduce impact on the environment because they may be performed with only one piece of normal construction equipment. In addition, gravel, crushed stone, cement or chemicals may not be required.