AIL’s Vist-A-Wall wire wall used in McTavish interchange
AIL was recently selected to design and supply MSE retaining walls for the McTavish Interchange on Highway 17, near Victoria, BC. The new interchange will provide a major upgrade to a busy signalized intersection, as McTavish Road is a vital access point for airport and ferry travelers, as well as local residents. The project features 11 Vist-A-Wall MSE Structural Wall Systems (2300 square meters) in all three types of construction: Wire Walls, Precast Panel Walls, and Two-Stage Precast Walls. A graffiti-resistant Vertical Grave Stake texture was chosen for the panels.
Wire Walls with natural cobblestone finish, will be used in areas where the aesthetics of Precast Panels are not required. Matching Precast Panel Walls and Two-Stage Precast Walls will be used everywhere else – the latter being for areas where excessive settlement is anticipated.
The walls are being constructed over an extended time frame in coordination with the contractor’s (Scansa Construction out of Victoria, British Columbia) project schedule. The first wall to be constructed is a gracefully curving Two-Stage Precast Wall. The first stage of that wall (as shown) is a wire wall with geosynthetic at the face. Once its desired settlement ranges are achieved, the second Precast Panel stage will be assembled on its own leveling pad and attached to the wire wall by a system of hooks and turnbuckles. The void is then filled with a granular material.
Every project brings challenges for AIL teams to work through and this one was no different. In fact, working closely with project owners, consultants and contractors has been critical to our success. In this case, an AIL Technical Sales Representative and Engineer worked very closely with all stakeholders to overcome a number of challenges:
- Geotechnical difficulties
- Low bearing capacities of soil foundations (lightweight fill was used)
- Continuous changes to drawings and specifications as design/build progresses
- Development of checklists and review criteria for MOTI-required daily monitoring by geotech support person, analyzed monitoring reports