Determination of initial stiffness of drilled shafts for the analysis of settlements under service loads

CARLOS A. PRATO; FEDERICO PINTO

Estocolmo

Conferencia; 11th International Conference on Piling and Deep Foundations; 2014

Deep Foundations Institute

The design of drilled shafts often incorporates large factors of safety, for which settlements under service loads are highly influenced by the initial elastic stiffness. In the case of groups of drilled shafts with typical spacing, the elastic shaft-soil-shaft interaction dominates the behavior even for loads close to the bearing capacity, for which the initial stiffness is a key parameter in the design. This paper describes typical trends in results obtained by means of different approaches currently available in the literature for the evaluation of the initial stiffness of a single shaft. An experimental technique that provides a rapid and inexpensive means for the evaluation of the initial stiffness is described, and the results obtained for typical cases are compared with analytical predictions.