What’s Happening in Traffic This Week
Traffic Shift on Valley Ridge Boulevard N.W.
When the tie-in for the southbound lane on Valley Ridge Boulevard N.W. is complete later this week, both southbound and northbound traffic will be shifted to the outside lanes to accommodate median construction. Please use caution when driving in this area.
We appreciate your patience during construction.
Balanced Cantilever Construction
A cantilever is a structural beam that is only anchored or supported on one end. The most common example of a cantilever is a balcony. In bridge construction, however, cantilever is used as a verb describing the construction method (since a bridge only connected on one side isn’t very useful).
Cantilevered bridges are often built in both directions from a single support to keep the load balanced, which is exactly the case for the Bow River Bridge. The segments are being added on either side of the piers using form travelers, similar to the image below.
At the abutments, the cast-in-place segments are supported with falsework rather than being cantilevered, since there is no way to balance the load on the other side of the abutment.
Valley Ridge Boulevard N.W. Interchange
Progress on the Basketweave Bridge
MSE wall construction for the abutments as well as formwork installation for the bridge deck are underway for the basketweave bridge separating traffic merging on and exiting off eastbound Trans-Canada Highway.
This bridge is one of four on the North project with steel girders. Shear studs are used to connect the steel girders to the concrete deck. The studs anchor the two components together and help to distribute the forces from the bridge deck to the girders, which in turn distribute forces to the abutments and pile foundations.
With both bridges for the ramp from southbound Stoney Trail to eastbound Trans-Canada Highway substantially complete, roadwork to connect them is underway.
Controlled Blasting Milestone
Last week marked a major project milestone with the conclusion of daily controlled blasts on the Paskapoo Slope. Localized, intermittent blasting will still be required to excavate two stormline trenches on either side of Stoney Trail.
None of the daily blasts in April 2021 generated ground vibrations of a sufficient amplitude to produce a seismograph waveform report (associated values are still retrieved from the histogram data and published at North Project > Controlled Blasting). Given this, the shallow depth of the localized blasts and the sporadic timing, notice will not be provided for intermittent blasts going forward. However, seismographs will continue to monitor ground vibrations and the reports will continue to be published each week.
Old Banff Coach Road S.W. Spread Footing Foundation
Test pits are used by geotechnical engineers to understand the shallow soil conditions below the surface (sometimes called subgrade). Test pit excavations allow for a visual inspection that boring a test hole does not, which helps the engineers to identify things like the size and composition of soil particles or differentiate between bedrock and large boulders.
At 17 Avenue S.W., test pits are being dug at the site of the shallow bridge foundation to confirm the material to be excavated and plan accordingly.
Springbank Ravine Drainage Culvert
Highway 8 / Stoney Trail Interchange
Excavation near Highway 8 has begun.