Introduction
The diverse geological and climatic conditions of Western Canada present unique challenges and opportunities in building foundation design. From the soft soils of coastal regions to the bedrock of the Rocky Mountains, selecting the right foundation type is critical to ensuring structural integrity, safety, and longevity. At HINGENEERING Consulting, we approach foundation design with a deep understanding of local conditions, tailoring solutions to meet the demands of each site and structure.
This blog explores the common types of building foundations used in Western Canada, their applications, and the factors influencing their design.
Shallow Foundations
Shallow foundations are ideal for sites with stable soil close to the surface. These are cost-effective and commonly used in residential and light commercial construction.
- Strip Footings
- Support load-bearing walls.
- Commonly used in residential construction (e.g., basements).
- Example: A strip footing underneath a wall (Photo 1).
- Spread/Isolated Footings
- Provide support for individual columns or piers.
- Widely used in light commercial, mixed-use buildings, and industrial applications.
- Example: Spread footings beneath columns (Photo 2).
- Raft/Mat Foundations
- Used for sites with poor soil conditions or for structures with heavy loads (e.g., high-rise cores, crane loads).
- Example: Raft foundation supporting tower cranes (Photo 3).
Deep Foundations
Deep foundations are required for sites with weak surface soils, high water tables, or significant load demands.
- Piles
- Driven Piles: Made of steel, concrete, or timber, driven into the ground.
- Bored Piles: Also called caissons; drilled and filled with concrete.
- Screw Piles: Helical piles screwed into stable soil layers, often used in seismic zones like British Columbia.
- Example: Concrete pile and screw pile installations (Photo 4).
- Pile Groups and Caps
- Combine multiple piles tied together with caps for high-load structures (Photo 5).
Hybrid Foundations
- Pile and Raft Systems:
- Combine piles and raft foundations to balance load transfer.
- Useful in areas with variable soil strata.
Frost-Protected Foundations
- Frost Walls and Footings:
- Extended below the frost line to prevent frost heave, essential in cold regions like Alberta and Saskatchewan.
- Insulated Shallow Foundations:
- Use rigid insulation to minimize frost penetration. (Photo 6)
- Frost Walls and Footings:
Specialized Foundations
For unique projects or challenging conditions, specialized foundation systems are employed:
- Rock Anchors
- Used for high-load structures built on bedrock.
- Grade Beams on Piles
- Tie piles together to distribute loads, commonly seen in industrial and infrastructure projects.
- Example: Grade beams on screw pile foundation for a water treatment station (Photo 7).
Considerations for Foundation Design in Western Canada
Several factors influence the selection and design of foundations in this region:
- Seismic Design
- In areas like British Columbia, seismic forces must be considered. Dynamic analysis and ductile detailing are critical to ensuring resilience.
- Permafrost
- Northern regions require innovative solutions like thermosyphons or elevated structures to combat permafrost challenges.
- Frost Depth
- Depths vary from 18 inches in Metro Vancouver to 6 feet in Fort McMurray, Alberta. Foundations must extend below the frost line to avoid frost heave.
- Soil Types
- Coastal areas: Soft clays and silts.
- Interior plains: Glacial till and sand.
- Rocky Mountains: Bedrock and gravelly soils.
- Drainage
- High groundwater levels necessitate drainage systems to prevent hydrostatic pressure and water ingress.
Conclusion
Building foundations in Western Canada require careful consideration of soil conditions, climate, and structural needs. By selecting the appropriate foundation type—whether it’s a shallow strip footing, a deep pile system, or a hybrid approach—HINGENEERING Consulting ensures projects are not only structurally sound but also optimized for local conditions.
Our expertise in foundation design helps clients navigate complex challenges while delivering cost-effective and sustainable solutions.
