DAMAGE FROM 20TH-CENTURY EARTHQUAKES IN EASTERN CANADA AND SEISMIC VULNERABILITY OF UNREINFORCED MASONRY BUILDINGS

This paper has been prepared as a reminder of past damaging earthquake s in eastern Canada and as a testimony of the damage suffered; isoseis mal maps of five selected eastern Canadian earthquakes are presented a s well as illustrations of their effects. Although features of the fou r older historical events reviewed herein are reasonably well document ed (although not to present standards), data of engineering significan ce needed to perform accurate seismic-resistance evaluations have been for the most part lost owing to the time elapsed. Hence, the damage e xamples presented herein should not be construed as a comprehensive su rvey but rather as a sampling of noteworthy failures. Since most of th e structural damage produced by these earthquakes was suffered by unre inforced masonry buildings, an overview of the seismic risks they cons titute and their main modes of failure is presented. The first step of a coordinated seismic risk reduction plan is also formulated; its app lication is recommended for the mitigation of economic and human losse s in future eastern Canadian earthquakes.