Seismic and Blast Retrofit of Reinforced Concrete and Masonry Buildings

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The performance of physical infrastructure during recent earthquakes clearly indicate that a large segment of existing building inventory is vulnerable to seismic excitations. Buildings designed prior to the enactment of modern seismic design guidelines that were developed in 1970's and 1980's, as well as those built more recently without the appropriate seismic design and detailing practices pose particularly high seismic risk. In the majority of cases, it is economically not feasible and practical to replace these deficient buildings with new and improved structures and building components. Therefore, seismic retrofitting (rehabilitation and strengthening) remains to be an effective and viable seismic risk mitigation strategy for civil engineering infrastructure. In addition to the seismic risk, critical infrastructure is vulnerable against another type of dynamic extreme load event in the form of accidental or maliciously intended deliberate explosion. Blast-resistant design of civilian infrastructure is not common in Canada. The National Building Code of Canada does not explicitly require blast-resistant design of buildings. Therefore, high-risk buildings, including the Canadian assets abroad (i.e., Embassy buildings) are vulnerable to blast threats, especially if the charge weight (bomb size) is high (as in the case of car and truck bombs) and the proximity of explosions to buildings (standoff distance) is close. While, strong earthquakes and bomb blasts are fundamentally different in the way they affect buildings, they both generate dynamic response of building components, potentially taking building materials beyond their elastic limits, benefitting from ductility and energy dissipation capacity of materials and components. There are commonalities between these two extreme load events, from which a common research program can benefit in developing infrastrcuture risk mitigation strategies. The objective of the proposed research program is to develop new and innovative seismic and blast retrofit methodologies for structurally deficient concrete and masonry buildings, as well as non-structural building components that form threat to the life safety of the occupants.