Seismic Site Classification

The National Building Code of Canada (NBCC) and International Building Code (IBC) emphasize that a quantitative approach is required for the determination of seismic site classification. The use of geophysical methods to determine seismic site classification can provide more detailed and accurate information when compared to the use of other methods, often leading to a better understanding of the areas load bearing characteristics and a more cost-effective foundation design.

CSR employs two geophysical methods for determining seismic site classification: One Dimensional Multichannel Analysis of Surface Waves (1D-MASW) and Vertical Seismic Profiling (VSP). 

The MASW method utilizes a string of geophones and a seismic source at surface. This method requires little surface preparation and can be completed quickly in most environments.

The VSP method requires a cased and grouted borehole to be installed as it relies on the use of a borehole geophone. The VSP method is ideal for cases where there is not sufficient surface area to conduct a MASW survey.