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Large-magnitude mining-induced seismic events can occur as a result of local rock mass stress increase. High apparent stress events can be used as a proxy to identify increases in local rock mass stress conditions. This paper proposes a relative apparent stress ratio (ASR) for quantifying apparent stress of a seismic population. Variations in ASR are analysed over time with reference to seismic hazard inferred from the magnitude of seismic events. The proposed ratio is examined through examples of seismic populations from a single deep Canadian mine. [ABSTRACT FROM AUTHOR]

The last version of the National Building Code of Canada was issued in 2010. The next version will be issued in 2015. In the code cycle between 2010 and 2015 significant changes have taken place in the seismic design provision. The main factor that drives these changes is an improved understanding of the seismic hazard across the country. Changes have also been introduced in the site effect factors. The structural design provisions have been appropriately adjusted to respond to changes in the estimates of hazard and the new site effect factors. There are also new provisions related to design in regions of low hazard, buildings with flexible diaphragms, buildings with inclined columns, passive energy dissipation systems, base isolation, rocking foundations, glazing systems, racks, and elevators. Some of the changes are briefly discussed. The main focus of the paper is, however, on the revisions to the structural design provisions. [ABSTRACT FROM AUTHOR]