When erecting upper structure the man manufactured materials are used. That is the reason of their excellent material properties. In the case of foundation the nature situation must be almost respected. The geostatical stress plays significant role on the subsoil behavior. The geostatical stress state is de facto natural form of the soil compaction. The soil has ability memorized the highest stress that has been ever loaded. The soil can be considered incompressible if the magnitude of a surcharge is lower. The excavation makes space for upper structure surcharge. The influence zone depth is defined like region where the geostatical pressure reduced by excavation together with upper structure loading exceed the original geostatical pressure. The Kantorovich method together with strategy of convolution was used to reach dimensional reduction when deriving analytical formulas. Derived formulas and presented graphs for influence zone depth estimation have considerable importance for civil engineering practice.