CPT-based method for toe resistance of driven piles in sand

Abstract

This study proposes a cone penetration test (CPT)-based toe resistance method for predicting toe resistance of pre-tensioned spun high-strength concrete (PHC) piles driven into sand. In total, 82 CPTs and 190 pile-driving analyser test piles were conducted at a construction site Myoungji site in the Nakdong River deltaic area west of Busan City in South Korea. Based on the toe resistance results obtained from the pile-driving analyser test analysis, the reliability of which was verified by comparison with on-site O-cell tests, a new CPT-based method for predicting the toe resistance of the PHC driven pile is proposed based on a statistical rank index. The new method consists of the geometric average of the CPT cone resistance and the loose soil ratio within the influence zone of 8D above and 4D below the pile toe (where D is pile diameter). The new method is found to provide better toe resistance prediction than previously suggested CPT-based methods.