A reliability-based decision framework for designing pile-load test programs -

Abstract

There is currently an inconsistency in the recommendations that are available in pile-design codes and practices regarding the required number of proof-load tests and the level of the proof loads for piles. This inconsistency has led to the implementation of unnecessarily costly pile load test programs in some cases and to insufficient or deficient load test programs in others. In both cases, the depletion of resources is the major outcome of the lack of rational methodologies for designing pile test programs. In this thesis, first, we study the effect of choosing different proof-load test programs on the reliability of piles. This is achieved by utilizing a Bayesian approach to update the capacity distributions of piles at a site given the results of the proof-load test program. The results of the updating process constitute necessary input to a proposed rational decision framework; it is reliability-based, pre-posterior decision-making framework to allow for selecting the optimal pile-load test program that would result in the maximum expected benefit to a project, while maintaining a target level of reliability in the pile design at the site. This proposed methodology is original, practical, and is based on site-specific information that is unique to any given project. In the final part of the thesis, the efficiency of the proposed decision framework is demonstrated by applying it on a practical design example.