Abstract: A method and apparatus are disclosed for building a reinforced sea wall or levee. The reinforced structure is designed particularly for use in areas of soft sub-soil such as those sub-soils found near the Gulf of Mexico which are capable of bearing loads of less than 5 pounds per square inch of weight. The structure includes first and second rows of soil-cement columns formed on opposite sides of the centerline of the structure. Soil-cement columns are formed by mechanically cutting the soft sub-soil and simultaneously hydraulically mixing the cut soft soil with a cement slurry injected at velocities of 200 feet per second or more. Reinforcing structural elements, preferably H-beams, are embedded in at least some of the soil-cement columns in each of the two rows. Tensile load bearing members, such as cables or beams, are interconnected between some of the reinforcing structural elements in the first row of soil-cement columns with some of the structural elements in the second row of soil-cement columns.

Abstract: A method is provided for forming an interconnected underground structure which avoids settling of adjacent soil structure. A plurality of underground support columns is initially formed, with the support columns being spaced apart in a predetermined pattern. Interconnecting holes are thereafter formed between the underground support columns, wherein the interconnecting holes are formed by mechanically cutting the soil and simultaneously hydraulically mixing the mechanically cut soil with slurry injected at velocities of 200 feet per second or higher while maintaining a positive hydrostatic head in the hole relative to adjacent soil. As the interconnecting holes are being formed, the diameter of each interconnecting hole is extended by positioning a second high velocity slurry nozzle near the outer diameter of the interconnecting hole which injects high velocity into the adjacent soil to hydraulically cut the adjacent soil and mix it with the slurry.

Abstract: Apparatus for cutting a concrete column by engaging the column between superimposed anvil and shear elements. The elements define a shear plane therebetween and the anvil element is conformed to embrace the column over an area of sufficient breadth to confine the portion of the column to the anvil side of the shear line against substantial fracturing. The elements are secured together for movement into and out of engagement with the column and an hydraulic cylinder is coupled between the elements to force the shear element against the column with sufficient pressure to fracture and crush the column.