Predicting driving transferred energy: case studies of steel piles

ABSTRACT This paper application of a method developed in Brazil for predicting driving transferred energy. The method was recently developed in Brazil and was used in short piles in 2019. In this more recent paper, it was sought to extend the application of the method to long piles (Pile length > 30 m) in soils of different characteristics. It is based on the pile measurements of permanent and elastic displacements during driving and calibration of the site-specific λ coefficient. The article validates the methodology in a case study of two sites with 159 dynamic tests of steel-driven piles in the cities of Santos (SP) and Itaguaí (RJ). Through calibration of λ, the energy predictions showed a good correlation to those obtained from the dynamic tests. There is an additional contribution to the original author’s analysis – increasing the previous testing database – about the correlation between λ and the pile length, as the study includes piles from 36 to 60 m in length – a range that was not included during the author’s first method evaluation. Its major advantage is allowing effective energy estimations in non‑instrumented piles as it is not practical to monitor every single pile of a construction driving site to assess the transferred energy. The presented method is useful in the practice of driven foundation and its quality control.