Results from a piling trial on bored, CFA and rotary displacement piles in stiff clay

摘要

Rotary displacement piles are finding increasing use on brownfield sites as restrictions on the disposal of spoil and/or noise pollution discourage the use of traditionally augered or driven piles. An increasing number of piling companies are offering new types of piles, displacement or otherwise, in order to maximise capacity whilst minimising concrete and spoil. To investigate a variety of pile types, a large piling trial has been carried out at a well characterised stiff clay test site in which 90 piles, of eleven different types including CFA, rotary and displacement, were installed. The trial was carried out jointly by BRE and Cementation Foundations Skanska Ltd (CFS) and was an opportunity to investigate: 1. measurements of drilling parameters during pile installation 2. vertical and horizontal ground movements during pile installation 3. novel displacement and enhanced capacity piles 4. changes in load carrying capacity with time of rotary bored concrete piles.