Foundations

Abstract

The ground immediately below the walls of a building is called the natural foundation or sub-foundation. It supports the dead weight of the building plus the superimposed loads imposed by the occupants furniture and other equipment. Bearing capacities of soils vary considerably and the load on the sub-foundation must be spread over a safe bearing area. For houses and small structures of two or three storeys this is usually achieved by means of a continuous concrete slab beneath the walls, known as a strip foundation (Fig. 11(A)).*