Rebuilding on old stilts: Another big project to be planned for the next 25 years

The Department of Transportation is in the process of constructing a completely new bridge over the old foundations, which will have to be reconstructed in 25 years.

With an estimated cost of approximately $200 million, the repair of the Pie-IX bridge, which connects Montreal and Laval, is one of MTQ’s most important ongoing projects.

When it launched the construction site in 2019, the ministry chose to return the bridge deck (the part where vehicles rotate), while retaining the foundations from 1966.

However, according to a 2015 internal report obtained by our Bureau of Investigation, MTQ experts recommended rebuilding the entire bridge, specifying that it would not be much more expensive than restoring just the deck.

The report noted that this would have resulted in a “brand new” bridge with an estimated life of “75 years”, “compliant with current standards” and “low maintenance cost”.

But that was not the choice made, an absurd situation in the eyes of the Quebec government’s professional union of engineers, which is currently on strike.

From an engineering point of view, this is a very bad idea. We are doing a project of over $100 million on organizations between 0 and 20 years old. “We run the risk of running into problems from the very beginning of the bridge’s life,” says its boss, Marc-Andre Martin.

The ministry considers that “the condition of the batteries did not require a complete rebuilding.”

“Intervention may be required on pile foundation units by the 25-year horizon,” acknowledges MTQ spokesperson Jill Bayer.

But according to state engineers, this is a “very bad management decision.” “It is very complex to recreate the foundation units below deck. It will increase costs tenfold, believes Mr. Martin.

He regrets that the ministry “disobeyed the advice of the engineers” to “accelerate the project”.

“There were standards from the start not to work in the river [donc sur les fondations] To avoid the phases of restricting environmental licenses. This is the typical case of political systems.

Another engineer’s report, dating from 2011, notes that it is important not to overburden the deck in order to comply with the standards in the event of an earthquake.

In fact, bridge piers are considered “unreinforced” concrete due to the lack of metal in the structure.

The union says this is another recommendation that has not been implemented.

Foundation units do not meet Canadian standards for highway bridges. The plans indicate that the project is not earthquake resistant. [majeurs] Marc-Andre Martin confirms.

MTQ asserts that “the design provides improvements in seismic response” without specifying whether it will meet established standards.

• Quebec government engineers resumed their strike on Wednesday, which began on April 22. The wage increase is the core of the dispute.

cracks and Pieces that pay off

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