Seismic Microzonation 

Classification of the seismic characteristics of soils has become an important issue for major Canadian cities, including the city of Ottawa, following the National Building Code of Canada. Carleton University and the Geological Survey of Canada (GSC) have applied different geophysical methods to carry out the site classification measurements within the city of Ottawa. Different methods were used extensively to evaluate the shear wave velocity of soils and rock in the city of Ottawa, Canada, from which the travel-time weighted average shear wave velocity (Vs) from surface to 30 m depth (Vs30) and the fundamental frequency (F0) were computed

 

Dr. Motazedian has been involved in seismic microzonation studies for major cities in Canada as a part of an NSERC-funded Canadian Seismic Research Network (CSRN) grant. His research team at Carleton University in collaboration with the Geological Survey of Canada (GSC) provided the first seismic microzonation map for Ottawa, which is available to the public in an interactive Google map.

Their research results have been influential in guiding improvements to the site amplification methods used in the 2010 and 2015 versions of the NBCC. Their results and activities have frequently been presented to the City of Ottawa in discussions on emergency preparedness.

Link to microzonation maps

Instructions for Installation of ArcReader and Opening of Interactive Site Class Map: 1) Copy the folder containing all the files directly to your computer. 2) Open the ArcReader Installation folder and double click on the setup.exe icon to begin the ArcReader installation on your computer. 3) When installation is complete, double click on the .PMF file to view and interact with the Ottawa Site Class map. 4) NB – In order for the street map layer to be visible, you must be connected to the internet.

Benefits to Canada/Ottawa

The research program has direct impacts on the mitigation against natural hazards and thus quality of life of Ottawa citizens. The general benefits of seismic microzonation are a better understanding of the potential for and spatial distribution of seismic hazards, and a rational basis for planning and policy making regarding mitigation of those effects. The microzonation maps generated during the course of this research program will be an essential tool for making earthquake emergency plans and for urban planning. In short, the maps will give the authorities relevant and concrete information on where to concentrate mitigation efforts. For example, a seismic hazard map identifying the relative potential for ground motion during an earthquake in different areas can be used to help predict earthquake effects on facilities, such as schools and lifelines, to allow ranking of priority areas or structures in terms of seismic vulnerability and thereby provide a rational basis for distribution of funds for upgrading, retrofitting and other remediation efforts.

Organizations which will benefit from having access to microzonation information include private industry, financial and insurance agencies, emergency services, community planners and groups governing funding and operation of utilities (e.g., water, sewer, gas, telephone, electricity), transportation networks (e.g., roads, bridges, tunnels, railways, ports, airports and mass transit systems), high occupancy structures (e.g., schools, high rise buildings), hazardous goods transportation and storage (e.g., toxic waste repositories and nuclear power stations).

The general benefits of seismic microzonation are a better understanding of the potential for and spatial distribution of seismic hazards. In addition, seismic microzonation information can be incorporated into building codes to improve seismic design of new structures. Assuming that a single building is built to better specifications as a result of this research and does not collapse in an earthquake, the money saved can easily reach a few millions of dollars, especially if injuries to people are avoided.