Fig. 9 Richmond Test Locations 4.0 Summary and Conclusions This paper presented the result of a microtremor testing campaign covering the City of Richmond and the three municipalities north of the City of Vancouver. In total, 212 tests were performed and their data analysed with Nakamura‟s method to determine the site period for each. In some cases, the Frequency Domain Decomposition technique was used alongside Nakamura‟s method, with mixed results. Several iso-period maps were generated from the results of this microtremor testing. These maps could be used as a starting point for determining underlying soil layers and input motion characteristics, estimating the seismic performance of a given area or predicting which magnitude of structures would be at risk as a result of a specific period of ground movement. The thick sediment layers of the City of Richmond exhibited a site period ranging from 0.6 to 5.7 seconds (0.18 to 1.67 Hz). The North Shore had much shorter periods on average, between 0.04 and 1.25 seconds in length (0.8 to 25 Hz). It is recommended that this study be expanded to other regions of Metro Vancouver to provide a more comprehensive summary of the region. In addition, further testing should be done to determine the effectiveness of the FDD technique in analysing ambient vibrations. Acknowledgements The authors thank Mr. Juan Carlos Carvajal of the University of British Columbia (UBC), Mr. Felix Yao of UBC, and Dr. John Cassidy of the Geological Survey of Canada for their collaboration during testing and analysis. Funding for this project was provided by the Natural Sciences and Engineering Research Council of Canada (NSERC). 458
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