Consolidated ground columns used for a perimeter digging of the excavations (possibly reinforced with steel tubes) and for the creation of a waterproof swab designed to counter the hydraulic substructure, allowing the excavations and the subsequent construction of the reinforced concrete slab in the absence of water. The blend used can be both boiacca (water and cement) and a ternary plastic mixture (water – cement – bentonite) according to a mixture of components designed to achieve the degree of permeability to be achieved.