Vancouver seawall mended after erosion

The seawall around Vancouver’s famous Stanley Park has been strengthened and rehabilitated after being eroded by the sea tides. A ribbon-cutting ceremony attended by Gregor Robertson, Mayor of Vancouver and the Honourable Denis Lebel, federal Minister of Transport, Infrastructure and Communities, was held July 5.

Worley Parsons was the consulting engineer responsible for the project, working with Vancouver’s Parks Department.

The ocean had gradually worn away the grout keeping the boulders together in the old seawall, says Rosalind Chong, an engineer-in-training with the Vancouver Parks and Recreation Board. The wall is around 75 years old and stands about 2 metres high. It has been reinforced and refaced with cast-in-place concrete, she says, and faced with granite.

One challenging aspect of the project according to Chong, was having to work alongside a 42-inch diameter pressurized sewer line which was made of fibre glass. The fibre glass material was introduced in the 1970s, but has been little used since so the construction industry does not have much experience with it. Sometimes crews had to work within a metre of the sewer, says Chong.

Another challenge was having to work in the narrow window between tides, she says. The tide has to be out substantially in order to do the work, which meant doing construction at night and in a four-hour window.

Worley Parsons did the design, site inspections, construction management and environmental monitoring on the project.

Several improvements to structures have been made around the Vancouver seafront and Stanley Park recently, amounting to $12 million in funding from the city and the federal Infrastructure Stimulus Fund. Besides the Stanley Park seawall rehabilitation, improvements were made to the seawall along English Bay, and upgrades were done to a sewer pump station, road paving, a pavilion and a performance theatre in Stanley Park.