Deep Foundation Analysis from Cone Penetrometers

Deep Foundation Analysis from Cone Penetrometers–A Reappraisal

Niazi, Fawad S. / Mayne, Paul W.

Geoengineering profession has witnessed continuous advancement in the application of cone penetrometer test (CPT) data for the analysis of deep foundations. Numerous methods based on scaling systems between CPT data and the pile capacity have been advanced. Rational methods founded on the CPT-based estimates of geoengineering parameters are also available for use in various analytical formulations. There are areas still demanding significant refinement. Diverse data sets of pile load tests and CPTs have played a key role in implementing this approach. The applicability of each method is limited for soil and pile typology. Pile capacity is not an agreed single value also. Each method requires one of the numerous criteria to define capacity value on the pile load-displacement curves. For most part, the manner in which CPT-based pile designs were advanced shows a certain degree of randomness. Furthermore, CPT readings are recorded in short-term at a high strain rate of loading. This differs significantly from the pile resistance in long-term involving setup or increased capacity overtime. This important yet missing component in pile-CPT correlations leads to uneconomical designs. These and other related issues are discussed in detail, and recommendations are made to steer future research on the topic.