Prediction, Performance, and Uncertainty in Dynamic Pile Load Testing as Informed by Direct Measurements from an Instrumented Becker Penetration Test

Abstract

Dynamic load testing and signal matching is commonplace for pile capacity verification but can be subject to nonuniqueness and uncertainty. Whether this uncertainty may be reduced with additional measurements requires further study. The instrumented Becker penetration test (iBPT) configured as a reusable test pile provides direct measurements of the dynamic response at the pile base and shaft. The distribution of static shaft friction in tension also is measured. This paper examined the sensitivity and potential improvements of such measurements in signal matching techniques. Different solution procedures were devised to analyze the same impact events, but incorporating static and dynamic iBPT measurements to varying degrees. The results suggest that whereas predictions of total ultimate capacity from signal matching generally are robust, differentiation of shaft versus base capacity may be more uncertain. Despite the nonunique solutions, dynamic predictions of shaft capacity agree reasonably well with static measurements.