Retaining wall design in Burnaby must follow the National Building Code of Canada (NBCC 2020) and CSA A23.3 for concrete structures, but the real challenge is the local geology. Burnaby sits on a mix of glacial till, marine clays, and silt deposits from the last ice age, with the water table often shallow near Burnaby Lake and Deer Lake. In our experience, many standard wall designs fail because they assume uniform soil conditions that simply don't exist here. For sloped lots along Capitol Hill or the Fraser River foreshore, we always recommend coupling the wall design with a slope stability analysis to check global failure modes before finalizing the reinforcement layout.
In Burnaby, the combination of glacial till over soft marine clay creates a two-layer soil profile that most standard design charts don't account for.
Service characteristics in Burnaby
Typical technical challenges in Burnaby
Burnaby's subsurface is notoriously layered — you can hit dense till at 2 meters in one lot and find soft marine clay at the same depth 50 meters away. This variability is the biggest risk in retaining wall design here. A wall designed for competent till may be undersized if it sits on clay, leading to excessive rotation or bearing failure. The shallow water table near Burnaby Lake and Still Creek adds hydrostatic pressure that can double the overturning moment. Without a proper site investigation, you're gambling with the wall's long-term stability, especially during the rainy season when the phreatic surface rises several feet.
Our services
We provide complete retaining wall design and analysis services for residential, commercial, and transportation projects in Burnaby.
Site-Specific Geotechnical Investigation
Boreholes, test pits, and SPT testing to determine soil stratigraphy, groundwater level, and shear strength parameters for the wall design.
Structural Wall Design & Detailing
Reinforced concrete cantilever, gravity, or MSE wall design per AASHTO LRFD and NBCC seismic requirements, including drainage and backfill specifications.
Seismic & Stability Analysis
Pseudo-static and dynamic analysis for seismic loads, global stability checks with Bishop's method, and settlement evaluation for the wall foundation.
Frequently asked questions
What is the typical cost range for retaining wall design in Burnaby?
For a complete design package including geotechnical investigation and structural drawings, you can expect to invest between CA$1,450 and CA$4,940 depending on wall height, soil complexity, and site access.
How deep does the soil investigation need to be for a retaining wall?
We typically drill or test pit to at least 1.5 times the wall height below the base, or until competent bearing material (glacial till or dense sand) is encountered, whichever is deeper. In Burnaby, this often means going 4-6 meters below grade.
Do I need a separate drainage plan for the retaining wall?
The reference range for this service in Burnaby is CA$1.450 - CA$4.940. The final price depends on the project scope and volume.
What type of retaining wall works best on Burnaby's steep slopes?
For steep slopes like those on Burnaby Mountain or near the Fraser River, a reinforced concrete cantilever or a tieback anchored wall is often required. MSE walls can work on gentler slopes, but the backfill must be well-compacted granular material.