Just-in-Time Continuous Flight Auger Piles Using an Instrumented Auger

Continuous flight auger (CFA) piles are constructed by drilling a CFA auger into the ground and, on reaching the required depth, pumping concrete down the hollow stem as the auger is steadily withdrawn. Current practice to predict the bearing capacity of CFA piles is to estimate the undrained shear strength-depth relationship for the overall site, and use a total stress analysis to predict a general pile bearing capacity. This analysis is often based on sparse site data collected from a location remote from the pile. This paper investigates the exploitation of new technology to enable a new improved approach to the procurement, design and validation of (CFA) bored piles. The ultimate target is that the final length of the piles will be determined on site, as they are constructed, and will be optimised to suit the actual local ground conditions.