The Mississippi River Bridges
2000-2001


mm122-3/haunch beams 4 m deep at the pier mm122-13 big girders
mm122-7/beams from u/s both bridges looking east

The Mississippi River in Ontario empties into the Ottawa River just west of the City of Ottawa, in the area known as the Ottawa Valley. The Ontario Ministry of Transportation (MTO) is in the process of widening and relocating Highway 417 from Ottawa going west. The construction of two six-span, side by side, 376 m long steel girder bridges is the longest bridge project in Ontario, and has been awarded to Dufferin Construction Company for $18.5mln. The river and 170 m wide floodplain at this crossing are classified as very sensitive from an environmental point of view, which called for unique geotechnical and structural solutions. Very sensitive leda clay did not allow for spread footings, and the design called for many steel H-piles to be driven to bedrock at the approximate depth of 46 m. We suspect that a geotechnical fault line runs in the vicinity and also the area is classified as earthquake prone. The bridge design was prepared in-house by MTO. REMISZ has been retained by Dufferin to provide structural Quality Verification Engineering. This work covered an independent and thorough review of the design, shop drawings, details, certification of conformance for the work in progress and completed, and resolution of many structural issues which may arise daily. Special earthqauke isolation, pendulum bearings, have been supplied from California. Steel girders were fabricated by Canam Structal in Quebec City. Because of the very long, continuous deck, the structure has substantial longitudinal movements and modular expansion joints were specified.

For more information about the proper selection of expansion joints, see our paper: Expansion Joints

Technical Data:
six spans (in metres): 54m-85m-65m-65m-65m-40m
total deck width of one bridge: 12.46 m
number of H-piles in plan: in abutments 24 and in a typical pier 28

Estimated Project Quantities:
55,000 tonnes of lightweight fill
5,550 cubic metres of concrete
3,000 tonnes of structural steel
3,000 tonnes of reinforcing steel
17,000 metres of H-piles
86,000 metres of drains

Ó Wojciech Remisz, M.Sc., P.Eng.