The next chapter in the seemingly never-ending saga of repairs on the Donahue Bridge is about to begin.
City council has green-lighted another $6 million for the bridge, which is about to undergo its eighth major reconstruction since 1982.
About 7,000 vehicles a day cross the Donahue, the main link between Sarnia and the Chemical Valley.
New problems came to light that have increased the cost, including engineering, about $1 million above last year’s estimate.
The city’s construction manager says the upgrades are normal for a bridge the size and age of the Donohue.
“It’s a piece of our infrastructure that’s at the end of its original lifespan,” said Robert Williams. “It’s important that proper rehabilitation is carried out.”
Although motorists driving across it might not notice, the Donohue is a six-lane bridge consisting of 10 spans crossing three separate corridors.
“It’s a least twice as big as an overpass on (Highway) 402,” Williams said.
It was built in 1969 to span the St. Clair rail tunnel and eliminate some street-level rail crossings on the spur line to the Sarnia Harbour grain elevators. Its rehabilitation has taken longer and cost more per-metre than it did to build the original Blue Water Bridge.
However, municipal officials say it’s still cheaper to repair than the $32 million needed to replace it.
Many of the new problems have been traced to incomplete and inadequate original drawings. Parts of the structure assumed to be there are absent, and there have been problems with the quality of materials used, including concrete.
City council awarded the latest contract on March 19 to Landform Civil Infrastructures Inc.
The work includes:
- Partial replacement of the East bridge deck.
- Replace pre-stressed concrete girders on the East bridge
- Replace sidewalks and parapet walls on the East bridge
- Replace concrete median between east and west sides
- Jacking up of two north-end abutments to repair the girder end and replace the bearing pads
- Replace select guide rail systems
- Repair some substructure components