Damage from 20th century earthquakes in eastern Canada and seismic vulnerability of unreinforced masonry buildings

Abstract

This paper has been prepared as a reminder of past damaging earthquakes in eastern Canada and as a testimony of the damage suffered; isoseismal maps of five selected eastern Canadian earthquakes are presented as well as illustrations of their effects. Although features of the four older historical events reviewed herein are reasonably well documented (although not to present standards), data of engineering significance needed to perform accurate seismic-resistance evaluations have been for the most part lost owing to the time elapsed. Hence, the damage examples presented herein should not be construed as a comprehensive survey but rather as a sampling of noteworthy failures. Since most of the structural damage produced by these earthquakes was suffered by unreinforced masonry buildings, an overview of the seismic risks they constitute and their main modes of failure is presented. The first step of a coordinated seismic risk reduction plan is also formulated; its application is recommended for the mitigation of economic and human losses in future eastern Canadian earthquakes. Key words: case histories, earthquakes, eastern Canada, seismic risk reduction plan, structural damage, unreinforced masonry buildings.