Barry's Advanced Construction of Buildings, 4th Edition

3Pile Foundations, Substructures and Basements

It is common for framed buildings to bear onto piled foundations. Steel and concrete columns, known as pile foundations, can be inserted (driven) or bored into the ground, transferring the building loads to loadbearing strata. The loadbearing strata may be a considerable depth below the surface of the ground. When building on previously developed sites, it is common practice to identify and remove existing foundations or to avoid them when placing the piles. Alternatively, some or all of the existing foundations may be reused to avoid unnecessary ground disturbance and help to reduce the environmental impact (and cost) of the new development. For temporary structures it is possible to use timber piles that can be left in the ground to decay naturally or steel screw piles that can be removed (unscrewed) when the building is taken down. In this chapter, the emphasis is on piled foundations, substructures and basements. The main functional requirements of foundations are described in Barry’s Introduction to the Construction of Buildings.

3.1 Pile foundations

The word ‘pile’ is used to describe columns, usually of reinforced concrete, driven into or cast in the ground in order to carry foundation loads to deep underlying firm stratum, or to transmit loads to the subsoil by the friction of their surfaces in contact with the subsoil (see Figure 3.1). The main function of a pile is to transmit loads to lower levels of ground by a combination ...