252 publications from this institution
A large proportion of existing building and bridge infrastructure across the world consists of seismically deficient non-ductile structural systems. Performance of structures during recent earthquakes have demonstrated seismic vulnerability of these systems, the majority of which were designed prior to the enactment of modern seismic codes, though some were designed more recently in areas where code enforcement provides challenges. These structures constitute considerable seismic risk, especially in large metropolitan centres. Because it is economically not feasible to replace a large segment of seismically deficient infrastructure with new and improved systems, retrofitting existing structures remains to be a viable seismic risk mitigation strategy. The objective of this paper is to highlight seismic retrofit strategies for deficient building and bridge infrastructures, with emphasis on experimental and analytical research conducted at the University of Ottawa. The retrofit strategies consist of structural upgrades at the system level, as well as at the element level. Non-ductile reinforced concrete frame retrofits, in the form of lateral bracing techniques, and concrete column and masonry wall retrofit methodologies are discussed. The use of innovative materials and techniques are presented.
A devastating earthquake and the resulting tsunami hit coastal areas of Indian Ocean on December 26, 2004. A team of Canadian engineers conducted a reconnaissance in Thailand and Indonesia. Their findings are presented in the paper in terms of performance of buildings, bridges, coastal structures and other physical infrastructure. It was observed that non-engineered reinforced concrete structures, low-rise timber frames and unreinforced masonry buildings suffered extensive damage due to hydrodynamic pressures generated by tsunami and impact forces induced by floating debris. Banda Aceh, Indonesia suffered extensive damage due to seismic excitations. A large number of non-engineered and engineered reinforced concrete frame buildings experienced partial or total collapse. A number of 3 to 5 story engineered reinforced concrete government buildings and shopping centers were damaged due to lack of proper seismic design practices. The engineering significance of disaster is presented in the paper with observations made during the reconnaissance visit.
