Observations of ground and structure movements during site redevelopment in Dublin

Abstract

An extensive monitoring system was installed to provide data on the behaviour of some retained masonry facades and on ground movements, resulting from basement excavation, during the redevelopment of a prestigious site in Dublin. Observations made by electrolevel beam sensors have implications for future facade retention system design. They revealed a thermally induced daily cyclic movement of the retained facades, which was partially irrecoverable. This resulted in permanent total deformations of up to 100 mm. An extended archaeological dig exacerbated the situation. The masonry was subjected to angular distortions of up to 1 in 125—values that are close to the tolerable limit. These movements ceased only when the facades were tied into the new structure. The retaining wall and temporary works support system for the new basement proved extremely stiff and watertight. Lateral wall movements were at most 1 mm and were significantly less than those predicted before the works. Back-analysis of the performanc...