Damage caused by the November 25, 1988, Saguenay earthquake

Abstract

The November 25, 1988, Saguenay earthquake prompted a site visit by a team representing the Canadian National Committee on Earthquake Engineering. This paper contains selected ground motion records in the form of acceleration-time histories, obtained from the Geological Survey of Canada, and corresponding response spectra. The horizontal acceleration spectrum obtained for Chicoutimi is compared with the design base shear coefficients from the 1980, 1985, and 1990 National Building Codes of Canada. Failures of natural slopes and embankments as well as both architectural and structural damage are discussed. The significant role played by the presence of soft subsoil in amplifying the ground motion and resulting damage is illustrated. Although no major structural failures occurred, there were many examples of poor performance, and in some cases failures, of unreinforced masonry walls. Concerns are expressed over the abundance of unreinforced masonry, particularly in schools and buildings such as hospitals, for which postdisaster performance must be ensured. Key words: earthquake, Saguenay, soils, structures, codes, masonry.