The new Walterdale Bridge creates a striking new entrance into Downtown Edmonton and a unique gathering place in the heart of North America’s largest urban parkland. The bridge is a gracious, single span, twin through-arch steel structure, spanning 206 metres from bank to bank across the North Saskatchewan River. It carries three lanes of northbound vehicle traffic, a sidewalk to the west of the roadway, and a separated shared-use path for pedestrians and cyclists to the east. The project also included the realignment of two major roadways to connect to the new river bridge alignment. The result is a signature structure that blends with its natural setting, creates a landmark gateway to the city, and refreshed the postcard view of the whole city.
The physics involved might make engineering students shudder. Steel fabricators didn’t just deliver 125-tonne puzzle pieces, they delivered 42 pieces deliberately misshapen so the forces within the bridge could form it into the right geometry.Elise Stolte, Edmonton Journal
Design Story 01
The old Walterdale Bridge was approaching the end of its life, and needed to be replaced. At first, the City of Edmonton was interested in a fairly pragmatic replacement. DIALOG had been working on an EXPO bid and West Rossdale Urban Design Plan. Though the EXPO bid didn't move forward, these projects planted a seed in everyone's mind about a new bridge.
Design Story 02
The location in the heart of the river valley is rich in history with nearby attractions. The area on the northeast side of the bridge has significant historic and cultural importance. There is the Traditional Burial Grounds/Fort Edmonton Cemetery which includes a memory circle, re-interment area, and historic graveyard.
Design Story 03
DIALOG prepared four bridge type options to share with the public. After consultation, the majority preferred the arch bridge concept.
Design Story 04
From there, we explored the styles of arch bridge that would be possible at a range of budgets. The chosen design fits best within the budget, site constraints, and integrates best with the urban environment.
Design Story 05
The selected design is a gracious, single span, twin through-arch steel structure, spanning 206m from bank to bank across the North Saskatchewan River. Not only was it a complex bridge to engineer, the construction was equally as challenging.
Design Story 06
Large thrust blocks are each made of about 600m3 of concrete and 44 steel micropiles installed 20m below the road elevation, which is as deep as a six-storey parking garage.
Design Story 07
Each arch rib is made up of 21 steel box segments with masses of up to 125 tonnes, using 1,500 bolts at each connection. End segments were erected from temporary berms.
Design Story 08
Central sections were assembled on the south bank, transported, and then lifted into place in two critical lifts. It was a highly precise task, and a race against time as the river was freezing up for winter.
Design Story 09
The bridge deck is a steel framework supporting a cast-in-place concrete deck covered with asphalt. It used 65 tonnes of reinforcing steel and 1,600m3 of concrete. The bridge currently carries three lanes of traffic, but is designed so that another lane can easily be added.
Design Story 10
The northeast bank has significant historic and Indigenous cultural importance. The new alignment and construction methods were carefully chosen to respect this.
It’s hard to believe now, but replacing Walterdale Bridge wasn’t always planned to be something special. So how did we go from a standard replacement bridge to a new icon that redefined the whole city?
