|CLIENT:||Department of Transportation & Works NL|
|CONTRACT TYPE:||Unit Price/Stipulated Sum|
H.J. O’Connell, a division of Bird, was the lead in a joint venture with Vancouver Pile Driving Ltd. in the construction of the new vertical lift bridge in Placentia. The scope of work consisted of replacing the Sir Ambrose Shea lift bridge, realigning the adjacent roadway Route 100 and the removal of the existing bridge upon completion of the new bridge.
The work consisted of building two 58 metre long temporary trestles with 600 millimetre pipe piles and a deck to enable a 150 ton crawler crane to construct the two new central piers deep in the Placentia Bay. The new lift bridge is 9,290 metres of 325 millimetre pipe piling; 2,200 square metres of sheet pile used as a cofferdam; 4,100 cubic metres of concrete; 1,000 tons of structural steel; and the mechanical and electrical components to allow the central lift span to open for the shipping lane through the narrow water channel.
During construction, the team encountered tidal ranges of over three metres with swift currents. The piling required for the south pier and south abutment increased substantially due to changes in geotechnical conditions, which required deeper driven piles. Structural steel was erected and the centre span was the major challenge as it involved shutting down the shipping lane to allow the erection of a 100 ton span using the mechanical and electrical systems of the permanent structure. The entire span of the bridge is 100 metres, consisting of two approach spans and a centre 30 metre span.