Improving the prediction of excavation-induced ground movements

Abstract

Activities associated with deep excavations cause ground movements. It is important to predict the deformation of the ground and adjacent structures during an excavation with reasonable accuracy. In contrast to the detailed methodology for limit equilibrium checks in TR26, there is not much guidance on how to overcome the challenges for predicting ground deformations accurately. This paper looks into the key difficulties of predicting excavation-induced ground movements, and attempts to improve the prediction incrementally by making some suggestions on the design and checking process. Specifically, three suggestions will be made in the paper. These are selecting soil stiffness based on expected strain levels in the soil, applying empirical checks on numerical predictions and adopting a progressive modification approach to observational method for excavation analysis and ground deformation prediction.