David Arnold, Arash Sahraei, and Timir Baran Roy
i Principal Structural Engineer at WSP, Ottawa, Canada, david.arnold@wsp.com
ii Structural Engineer at WSP, Ottawa, Canada, arash.sahraei@wsp.com
iii Structural Designer at WSP, Ottawa, Canada, timirbaran.roy@wsp.com
ABSTRACT
Centre Block, Canada’s iconic Parliament building, is currently undergoing a significant rehabilitation. Part of the planned work includes excavation of three additional partial basement levels. Throughout the excavation, the building will be partially supported on temporary steel shoring. This will be a system of drilled steel piles that will be exhumed and braced as the excavation proceeds. Vertical movements of the temporary steel shoring as well as the adjacent rock mass are expected. These vertical movements have the potential to damage Centre Block’s heritage unreinforced masonry walls. A project specific vertical movement limit has been established to define an acceptable level of control. Development of the movement limit has accounted for the specific geometry and materials of Centre Block’s masonry walls as well as the building’s structural interaction with the shoring system. This paper discusses the non-linear analysis performed to establish the vertical movement limit. It is observed that many of Centre Block’s walls have significant capacity to tolerate localized vertical movements. However, the associated load redistribution caused by the vertical movements needs to be considered in the shoring design. A summary of the vertical movement limits and corresponding shoring specification requirements is provided.
KEYWORDS: Canadian Parliament, Centre Block, unreinforced masonry, excavation induced movements, non-linear analysis.
123-Arnold.pdf
