Seismic Risk Analysis

Written by Paul Couch & David Mancini Saturday, 07 July 2007 09:54

Evaluation of Structural Damage to Buildings and Loss Estimation in the Downtown Core of Vancouver, British Columbia

The goal of this project was to perform an in-depth seismic risk analysis of Vancouver's downtown core for different levels of ground shaking intensities (defined by the Modified Mercalli Intensity (MMI) scale for events VI-XII). 

First, a relational geodatabase was created using Microsoft Access. This involved relating many different attribute tables, from various sources, to the building inventory. The building inventory is a single attribute table consisting of 10,350 building in our study area and was supplied by the Greater Vancouver Regional District (GVRD) to Dr. Carlos Venutra, P.E., P. Eng., director of the Earthquake Engineering Research Facility Department of Civil Engineering at UBC. After the relational geodatabase was created, two main sections of seismic risk were analyzed: direct monetary losses and direct social losses (injuries and casualties). This required us to evaluate structural and non-structural damage to buildings in the database and estimate from this the expected monetary and social losses. Over 200 maps showing the results were created and modeled on a per block basis. The estimation of direct social losses required us to develop a methodology that would estimate the number of injuries and casualties per building for MMI events VI-XII. Our methodology combines data from multiple sources as it uses Statistics Canada census tract population data, building inventory data supplied by the GVRD, Damage Probability Matrices (DPM's) supplied by the Earthquake Engineering Research Facility at UBC., and casualty rates supplied by HazUS. Our methodology also considers the time dimension as it produces results for a 2 a.m., 2 p.m., or 5 p.m. earthquake scenario.

Read the full technical report here.