Bayesian updating for one-dimensional consolidation measurements

After a geotechnical design has been developed, it is common to monitor performance during construction using the observational method by Peck (published in 1969). The observational method is a process where data are collected and geotechnical models updated, allowing timely decisions to be made with respect to risk and opportunity by asset owners or contractors. The observational method is similar to the mathematical formulation for Bayesian updating of material parameters based on measurements. A proof of concept study has been performed to assess the potential for Bayesian updating to be combined with the observational method to allow timely and accurate decision-making during construction of embankments on soft soils. The method was able to converge to an accurate solution prior to 50% consolidation assuming small measurement errors. It is also demonstrated that confidence in the predicted settlement is relatively low at the prior 'design' stage and rapidly increases with three or four measurements spaced over time during the posterior 'construction' phase. Key words: statistical analysis, Bayesian probability analysis, embankments. Apres avoir realise une etude de conception geotechnique, on mesure habituellement les performances durant la phase de construction a l'aide de la methode observationnelle de Peck (publiee en 1969). Celle-ci consiste en un processus durant lequel des donnees sont recueillies et les modeles geotechniques mis a jour, ce qui permet la prise rapide de decisions par les proprietaires et entrepreneurs. La methode observationnelle est similaire a la formulation mathematique d'adaptation bayesienne des parametres de materiau basee sur des mesures. Une etude de validation de principe a ete effectuee pour evaluer la capacite de l'adaptation bayesienne a etre combinee a la methode observationnelle dans le but permettre la prise rapide et precise de decisions lors de la construction de talus sur sols mous. La methode a ete en mesure de deboucher sur une solution precise avant la consolidation a 50 %, en supposant la presence de petites erreurs de mesure. On a egalement demontre que le degre de confiance accorde a la prediction de tassement est relativement faible lors de l'etape prealable de << conception >> et qu'il augmente rapidement en presence de trois ou quatre mesures espacees dans le temps durant la phase ulterieure de << construction >>. [Traduit par la Redaction] Mots-cles : analyse statistique, analyse bayesienne de probabilite, construction de talus.
Introduction After a geotechnical design has been performed, it is common to monitor performance during construction using the observational method (Peck 1969). The observational method is a process where data [...]