ABSTRACT
This chapter concerns itself with the use of conventional piles as underpinning. As already described (Chapter 1) the objective of underpinning is to create new foundations on to which the existing load may be wholly or partially transferred without harmful movements. The need to use piles comes about when
(a) the normal procedure of underpinning by excavating and forming mass concrete foundations (see Chapter 2) is not possible, or is uneconomical either because of the depths to which the excavations would to be taken, or because of problems caused by groundwater; or
(b) the loads on the ground from the existing structure are so great that the large dimensions of the excavations necessary for normal underpinning would cause the structure (or other nearby structures) to settle or move sideways by unacceptable amounts.
