Too many developers in Burnaby assume the 2020 National Building Code of Canada map is enough for their site. It is not. That map gives you a regional hazard, but it misses the local soil column that can amplify or dampen shaking. We have seen projects where a standard site class D designation led to over-designed foundations, while others under-designed because shallow fill layers were not identified. A proper seismic microzonation study refines that regional value into a site-specific response, saving both cost and risk. Before pouring concrete, we recommend combining surface wave surveys with a tomografía sísmica to image velocity contrasts across the property, and a densidad cono de arena to verify compaction of existing fills that could settle during shaking.
In Burnaby, a 20-meter change in location can shift your site class from C to E, changing your base shear by 40 percent or more.
Service characteristics in Burnaby
- Surface-wave testing (MASW) to measure VS30 profiles following ASTM D4428
- Borehole sampling with SPT and CPTU to classify soils and measure pore-pressure response
- One-dimensional equivalent-linear site-response analysis using SHAKE or DeepSoil
Typical technical challenges in Burnaby
We deploy a trailer-mounted MASW source and a 48-channel seismograph to acquire surface-wave data across the site. The crew lays out a 115-meter geophone spread, and we record at least five shot gathers per line. Data processing in SeisImager picks the Rayleigh-wave dispersion curve, which we invert to obtain a VS30 profile. The whole field campaign for a typical 1-hectare lot in Burnaby takes about six hours, including setup and quality control. We then combine those velocities with SPT and CPT logs from our drill rig to produce the final microzonation map. The process is efficient enough that we can deliver preliminary results within a week of fieldwork, which keeps your design schedule on track.
Our services
We provide two complementary microzonation services tailored to Burnaby's varied geology.
Site-Specific Response Analysis
Combines MASW, SPT, and CPT data with equivalent-linear or nonlinear ground-response models to produce acceleration response spectra, amplification factors, and liquefaction hazard maps for your building footprint.
Seismic Microzonation for Master-Planned Developments
For larger subdivisions or multi-building campuses in Burnaby, we produce a zone map that classifies each parcel by VS30, site period, and liquefaction potential, so you can optimize foundation types across the entire development.
Frequently asked questions
How does seismic microzonation differ from the NBCC 2020 site classification?
The NBCC 2020 provides a single site class (A through F) based on average VS30, but it does not capture local amplification or basin-edge effects. Seismic microzonation uses site-specific wave velocity profiles and numerical modeling to produce a response spectrum that reflects the actual soil column beneath your Burnaby project, including higher-mode effects and soil nonlinearity.
What is the typical turnaround time for a microzonation study in Burnaby?
Fieldwork for a 1-hectare site usually takes one day. Data processing and report preparation require another five to seven business days. For larger developments or sites with complex stratigraphy, allow up to three weeks from mobilization to delivery of the final microzonation map and response spectra.
Does seismic microzonation include liquefaction assessment?
Yes, it does. Our microzonation workflow incorporates SPT- and CPT-based liquefaction triggering analyses following the NCEER/Youd-Idriss (2001) method. We map areas where loose saturated sands or silts in Burnaby's low-lying zones could liquefy under the design earthquake, and we provide recommended mitigation measures such as ground improvement or deep foundations.
How much does a seismic microzonation study cost in Burnaby?
The cost ranges between CA$6.280 and CA$25.870 depending on site size, number of test locations, and the depth of investigation required. A typical single-lot study with MASW, two SPT borings to 20 m, and site-response analysis falls around the lower end of that range. Larger master-planned sites or those requiring advanced nonlinear modeling approach the higher end.