Back-analysis of an embedded retaining wall in stiff clay

Abstract

The performance of embedded retaining walls during and after excavation is commonly predicted using numerical techniques and assessed by field monitoring. However, subsequent back-analyses of post-construction monitoring data are rarely undertaken. The purpose of this paper is two-fold: (i) to provide a comprehensive post-construction review of site information and monitoring data from a construction site in central London and (ii) to detail results from a parametric study undertaken as part of the back-analyses of five key embedded retaining wall sections. The importance of accounting for the effects of non-linear soil stiffness when predicting wall deflection profiles is highlighted by the parametric study. Good agreement between the numerical model and field monitoring data was achieved through the back-analysis exercise. Differences in the predicted Class C wall deflection profiles are attributed to varying temporary support systems and complex 3D site geometry. Best practice recommendations relating to field monitoring and a new streamlined methodology for performing similar back-analyses are proposed.