Chapter 9: Foundation design decisions

The objective of this chapter is to dispel the widely held view that foundation engineering is simply a matter of designing and then constructing a foundation to carry a given load. In practice, many key decisions have to be made in developing the conceptual design before detailed design calculations can be undertaken. An approach to tackling these key decisions is given. For foundations to be constructed economically and sustainably it is necessary for the geotechnical and structural engineer to work closely together from an early stage. Examples are given of the benefits associated with close cooperation across the design team. Great emphasis is placed on recognising that foundation engineering is a ‘process’ involving a number of interlinked operations. Success depends on the skill of the engineers and operators and the way these operations are monitored and modified as work progresses. The chapter contains a number of case histories describing problems that emerged during construction and how these were solved. They illustrate how important it is to keep the ‘geotechnical triangle’ in balance.