Evaluation of Cone Penetration Test- and Piezocone Penetration Test-Based Pile Design Methods for Estimating the Ultimate Axial Capacity of Driven Concrete Piles

This study presents a comprehensive evaluation of 30 cone penetration test (CPT)- and piezocone penetration test (PCPT)-based pile design methods, indirect CPT method, and one static analysis method for estimating the ultimate axial capacity of precast prestressed concrete (PPC) driven piles, using a dataset collected across Louisiana. A total of 126 static pile load tests (SLTs) were compiled, each accompanied CPT data and soil boring data located near to pile location. The methods assessed included 24 direct CPT-based methods, six PCPT-based methods, indirect CPT method, and one static analysis pile design method. A combination of statistical and mathematical evaluation criteria, multidimensional scaling (MDS) analysis, and reliability-based analysis criteria were applied in this study to evaluate the methods based on their ability to estimate the measured ultimate axial capacity of tested piles. In addition, a modified Schmertmann method is proposed and evaluated. Among all the methods, the University of Florida, Philipponnat, KTRI, Modified Schmertmann, University of Western Australia, Laboratoire Central des Ponts et Chaussées, Van Dijk and Kolk, De Ruiter and Beringen, Enhanced Unicone, and German methods demonstrated the highest accuracy and reliability in estimating the ultimate pile capacity in Louisiana soils. The static analysis method showed moderate predictive performance, whereas the indirect CPT method showed poor performance in estimating ultimate pile capacity. This study provides practical guidance for selecting reliable CPT-based methods for accurately estimating the axial capacity of pile foundations.