A CPT-Based Soil Resistance to Driving (SRD) Method for Offshore Pile Driveability Analyses

This paper presents a method for predicting soil resistance to driving (SRD) for a wide range of soil conditions and pile sizes commonly encountered offshore, including large diameter monopiles which are widely used to support offshore wind turbines. The method uses in situ measurements from the cone penetration test (CPT) to calculate SRD.

The SRD method has been verified by performing pile driving back-analyses for a large number of offshore sites across the globe; over 1000 individual pile driving records were reviewed, with the highest quality records being selected for method calibration. A number of sites also included pile monitoring data, which provided further insights into the hammer performance and soil resistance during installation. The pile driving stresses derived from the pile monitoring data were considered when developing the SRD method, to ensure compatibility and increase confidence for forward predictions of pile driveability and pile fatigue.

The method outlined in this paper is shown to perform well for a wide range of soil conditions and pile sizes. When compared to another SRD method, the new method appears to perform better in heavily overconsolidated clays and performs similarly well for other ground conditions.