An alternative CPT averaging procedure to estimate pile base capacity

A wide variety of cone penetration test (CPT) based methods of estimating pile base capacity exist. These
methods typically link the base resistance at some specified pile base settlement level to a representative
value of cone resistance qc through a correlation factor to account for pile installation effects. The
representative or design qc value is derived using procedures which typically average the cone resistance
over a number of pile diameters above and below the pile tip. As the averaging procedure varies from region
to region attempts to unify design methods are hampered by uncertainties related to the design value that
should be adopted. In this paper two series of laboratory CPT tests on layered soil deposits are used to
calibrate an alternative CPT averaging procedure that, when compared to existing procedures, can adequately
capture the transition in qc across a variety of soil conditions.