The Ministry of Transport is building a brand new bridge on old foundations, which will have to be redone within 25 years.
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With an estimated cost of nearly $200 million, the repair of the Pie-IX bridge, which connects Montreal and Laval, is one of the most important projects underway at the MTQ.
When it launched the construction site in 2019, the ministry chose to redo the deck of the bridge (the portion on which vehicles circulate), while retaining the foundations which date from 1966.
However, according to a 2015 internal report obtained by our Bureau of Investigation, MTQ experts recommended the complete reconstruction of the bridge, specifying that it would not be much more expensive than redoing only the deck.
This would have resulted in a “completely new” bridge, with an estimated lifespan of “75 years”, “compliant with current standards” and “low maintenance cost”, noted the report.
problems quickly
But this is not the choice that was made, a situation which is absurd in the eyes of the Professional Association of Engineers of the Government of Quebec, which is currently on strike.
“From an engineering point of view, this is a very bad idea. We are doing a project of more than $100 million on foundations that have a lifespan of between 0 and 20 years. We risk having problems from the start of the life of the bridge, ”says its president, Marc-André Martin.
The ministry judges that “the state of the batteries did not require their complete reconstruction”.
“An intervention could be required on the foundation units of the piles in a horizon of 25 years”, recognizes the spokesperson for the MTQ, Gilles Payer.
But according to state engineers, this is a “very bad management decision”. “It is very complex to redo foundation units below a deck. It will increase the costs tenfold, ”believes Mr. Martin.
He regrets that the ministry went “against the advice of the engineers” to “accelerate the project”.
“There were criteria from the start not to work in the river [therefore on the foundations] to avoid the stages of restrictive environmental authorizations. This is the typical case of political orders, ”he says.
Unreinforced concrete
Another engineer’s report, which dates from 2011, specifies that it is important not to increase the weight of the deck in order to comply with the standards in the event of an earthquake.
Indeed, the bridge piers are considered to be “unreinforced” concrete because of the low presence of metal in the structure.
The union says this is another unimplemented recommendation.
“The foundation units are not to Canadian highway bridge standards. On the plans, it is indicated that the project is not resistant to [major] earthquakes”, underlines Marc-André Martin.
The MTQ affirms that “the design provides for improvements in the seismic response” without specifying whether this would meet the standards in force.
According to the most recent inspection report of the Pie-IX bridge, in 2018, several piles (in photo) contained cracks qualified as “medium” or “significant”. There are also pieces of concrete coming off. However, their condition is considered “acceptable”, which motivated the ministry to keep them.
