Helical Piers for a Steep Staircase at Sentier des Grèves, Quebec, Canada

The City of Quebec, in Canada, had the vision to connect the St. Lawrence waterfront (specifically the Samuel-de-Champlain Promenade) to the top of the hill near the city’s bridges. Their goal was to complete the ‘Sentier des Grèves’, a scenic 1.7 km pedestrian trail running along the St. Lawrence River between Jacques-Cartier Beach Park and the Pierre-Laporte Bridge. This was to provide locals and visitors, direct access to Gagnon Beach as well as offer stunning views of the river and surrounding infrastructure.

Designed to respect the surrounding natural environment, the trail includes interpretive panels that explain the region’s tides and landscape evolution. It also offers alternate paths that are accessible depending on the changing tidal conditions. This allows for optimal use of the site year-round.

To assess the feasibility of this project, engineers from WSP reached out to Techno Metal Post a year before construction began. They needed an alternative foundation solution that would handle the site’s challenging conditions-something that traditional methods simply could not handle. After a thorough evaluation, it was determined that installing helical piers would be the most suitable solution even in these extreme conditions. With this confirmed, detailed plans and specifications were drawn up to move the project forward using this innovative technology.

Year Completed: 2015 (10th anniversary of the project’s completion)

Dealer: Techno Pieux Québec Est

Client: Les Constructions Bé-Con Inc.

Location: Sentier des Grèves, Qc, Canada

Engineering Firm: WSP

General Contractor: Les Constructions Bé-Con Inc.

Project Objectives: To install a wooden staircase on a helical pier foundation while minimizing the environmental impact, noise, and construction time.

Key Challenges: Steep slope (40 degrees)

Advantages Over Other Methods:

• Quick installation
• Compact installation equipment
• No need for excavation on the slope
• Lower cost compared to driven or bored pier solutions

Soil Type: Fill is composed of rock fragments and sandy gravel

Installation Time: 5 days

Crew Size: 3 people (1 installer, 1 welder, 1 manual laborer)

Piers Used: 36 x P5

Equipment Used: R2D

Load Capacity:  25 kN (compression) per pier in service

Torque per Pier: Approximately 3,300 lb-ft

Engineer’s Recommendations: Average embedment depth: 8'-11"

Structure Details: The piers support a braced wooden structure.