Observed Performance of a Sheetpile-Supported Excavation in Chicago Clays

Abstract

Ground surface settlements and lateral wall movements measured during construction of a 13.1–18.0 m deep mixed-support excavation in Chicago are presented. The excavation was supported with sheetpile walls, two or three tieback levels, and one level of internal diagonal bracing. This paper describes the measured ground and wall responses, correlates the responses with construction activities, and evaluates the responses in light of the subsurface conditions, support system stiffness, and other nearby excavations. Expected performance based on semiempirical correlations is compared with the measured response. Lateral wall movements at this and an adjacent excavation are used to indicate the accuracy with which one may be expected, at best, to predict lateral wall deformations in similar conditions.