The Ministry of Transport and Sustainable Mobility (MTMD) will rely on the recommendations of a specialized New York company when planning the replacement of the suspensions of the Pierre Laporte Bridge.
• Also read: The Pierre Laporte Bridge will last at least another 50 years
The services of the specialized company Bridge Technology Consulting (BTC) were used to carry out tests on samples of wires and hangers and evaluate them, according to documents obtained by Le Journal through a request for access to the “information”. .
The American company, which describes itself as a “world leader” in bridge structure monitoring technologies, was commissioned in 2022 by the CIMA+/Tetratech consortium as an expert “to assist the MTMD in assessing the resistance of support cables”. indicates a document prepared by the Ministry.
“The bridge remains safe”
“The aim of this study is to prioritize the interventions to be carried out on the routes,” it says.
“Although the bridge remains safe, ongoing maintenance and repair interventions are required as it is important to ensure the longevity of this strategic structure in Greater Quebec,” the MTMD adds.
The Pierre Laporte Bridge between Lévis and Quebec has 160 hangers, 40% of which have been renovated so far (see box). Their function is to connect the support cables to the bridge deck.
Although their wear and tear is normal over the life of the infrastructure, their condition has required emergency work in recent years and has prompted the Ministry to accelerate the program to replace them.
BTC submitted its 200-plus page report to the ministry on May 30.
Cable break
“Visual inspections and test data indicate that the lines are undergoing active degradation, particularly near the base area [qui connecte les suspentes au tablier du pont, NDLR]», we can read in the report, several passages of which were redacted before being submitted to the Journal.
“This manifests itself in broken wires, crack propagation, reduced fatigue life and reduced hanger strength. “It is therefore important to check the cables in the base area regularly, at least every six months,” we add.
Each hanger is actually made up of two hanging cables, which themselves consist of more than 300 wires.
The authors identify 43 lines that need to undergo intervention (either replacement or strengthening) “as soon as possible” in 2023, as well as 19 more that need to be strengthened before the start of 2024.
In a summary document dated late August, the MTMD claims to have carried out 79% of the required interventions and that a contract will be awarded to complete the work within the recommended time frame.
Good for 50 years
In an interview with Le Journal a few weeks ago, an MTMD engineer also indicated that they would follow BTC’s recommendations.
Carl Fortin, technical coordinator at the Major Projects Directorate of the Pierre Laporte Bridge, reassured about the status of construction work, saying that the bridge “could easily live another 50 years” if we take care of it, and “currently “Is that what we do?”
The hangers of the Pierre Laporte Bridge
As of June 15, 2023, 64 of 160 lines (40%) have undergone intervention:
- 27 hangers replaced with new ones
- 11 temporary hangers installed
- 26 consolidated hangers
The complete replacement of the hangers is planned by the end of 2029.
Source: Ministry of Transport and Sustainable Mobility
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