Rebuilding on old pillars: Another major project planned over the next 25 years

The Department of Transport is in the process of building a brand new bridge on old foundations that will need to be replaced within 25 years.

At an estimated cost of nearly $200 million, the repair of the Pie IX Bridge connecting Montreal and Laval is one of the most important projects being undertaken at MTQ.

When the site opened in 2019, the ministry decided to rebuild the bridge deck (the part where vehicles travel) while preserving the 1966 foundations.

However, according to a 2015 internal report by our Bureau of Investigation, MTQ experts recommended a complete reconstruction of the bridge, saying it would not cost much more than just rebuilding the deck.

This would have resulted in an “all new” bridge with an estimated lifespan of “75 years,” “conforming to current standards,” and “low maintenance costs,” the report said.

However, that is not the choice made, a situation absurd in the eyes of the Quebec government’s professional association of engineers, which is currently on strike.

“Technically, that’s a very bad idea. We are running a $100+ million project on endowments that have lives ranging from 0 to 20 years. We risk having problems from the very beginning of the bridge’s lifespan,” says its President Marc-André Martin.

The ministry believes that “the condition of the batteries did not require a full reconstruction”.

“In a 25-year horizon, intervention on the foundation units of the piles could be necessary,” admits MTQ spokesman Gilles Payer.

However, according to state engineers, this is a “very bad management decision”. “It is very complex to renew foundation units under a deck. It will increase the cost tenfold,” believes Mr. Martin.

He regrets that the ministry went “against the advice of the engineers” to “speed up the project”.

“Right from the start there were criteria not to work in the flow [donc sur les fondations] to avoid the phases of restrictive environmental permits. That’s the typical case of political commissions,” he says.

Another 2011 engineering report states that it is important not to add weight to the deck to meet standards in the event of an earthquake.

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

The union says this is another unimplemented recommendation.

“The foundation units do not meet Canadian standards for highway bridges. The plans state that the project is not earthquake proof [majeurs] “, emphasizes Marc-André Martin.

The MTQ confirms that “the design incorporates improvements in seismic response” without specifying whether this would meet applicable standards.

  • Quebec government engineers Wednesday resumed their strike that began on April 22. The focus of the dispute is the increase in remuneration.

cracks and pieces that come loose



Pie IX bridge



screenshot

According to the Pie IX Bridge’s latest inspection report in 2018, several piles (pictured) had cracks that were classified as “moderate” or “major”. There are also pieces of concrete that come loose from it. However, her condition is considered “acceptable,” which motivated the ministry to keep her.

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