Constructing this bridge involves a tremendous amount of engineering and technical work. Along with that comes a lot of acronyms and technical terms, so we’re decoding some of this project language in a new segment we’re calling, ‘Learn the Lingo’.

Bridge Deck

The bridge deck refers to the surface of the bridge where vehicles, cyclists and pedestrians travel. In the case of the Third Crossing the latter two groups will have a four-metre multi-use path, with a dividing wall separating the active transportation pathway from vehicle traffic.

Bridge Piers

These are the vertical shafts that are placed in the river all the way down to bedrock and capped with a large concrete top. The shafts act like the legs of the bridge and the cap like a tabletop providing support for the bridge girders.

Bridge Girders

The bridge girders are the horizontal concrete beams that provide support for the bridge deck. The ends of the girders rest on the bridge piers. The concrete girders for the Third Crossing are nearly 50 metres in length and weigh over 85 metric tonnes!

Causeway-Trestle Solution

A hybrid construction approach used for the Third Crossing. It involves both a temporary causeway (a raised path with no opening underneath) and a trestle (a temporary work bridge) for crews and machinery to access the bridge piers and superstructure. The trestle lift span can move up and down, which means that it can move to allow boaters to safely pass underneath during construction. While the causeway blocks water movement because it extends down to the riverbed (apart from five wildlife eco-passages), space underneath the trestle allows wildlife to safely travel up and down the Cataraqui River.

Integrated Project Delivery (IPD)

The model used for the planning, design and construction of the Third Crossing. In this model the budget of $180M is set and the City, contractor (Kiewit) and designer (Hatch) work together to deliver the project within that budget. Together, all partners share the risk and reward to deliver the best possible project.

Reinforcing Steel

A steel bar, often referred to as rebar, that is used in reinforced concrete to add strength to a structure. While concrete and steel are both strong under compression, steel makes up for concrete’s weaker tensile (i.e., bending) strength. Together they make a stronger final product, helping to prevent and minimize cracks in the concrete due to movement and traffic loading.

Weathering Steel

A type of steel alloy that forms a protective layer on its surface and is resistant to corrosion. This means it has a protective coating (called a patina) that gives the steel a rust-like appearance (without rusting) after being exposed to weather. You will notice that steel spans from Pier 17 to Pier 19, close to the east shore, are made of this steel alloy. The significant benefit of using weathering steel is that it does not need to be painted to provide corrosion protection. It also eliminates the cost and environmentally sensitive work to regularly re-paint it over its life.