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De la Concorde overpass collapse
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De la Concorde overpass collapse
The De la Concorde overpass collapse occurred at a bridge over Quebec Autoroute 19 in Laval, Quebec, Canada, at midday on September 30, 2006. On that Saturday, around 12:30 pm, the centre section of the south lane of an overpass (65-foot or 19.8-metre section of a three-lane overpass) collapsed in Laval, a suburb of Montreal, on Boulevard de la Concorde running over Autoroute 19. The collapsed section crushed two vehicles under it, killing five people and seriously injuring six others who went over the edge while travelling on the overpass. The north-lane half, along the same bridge, did not collapse. The autoroute was closed for almost four weeks, "disabling an important north-south link between Montreal and its northern suburbs as well as the Laurentian region".
A number of people had noticed that the overpass was not in good shape:
When the Quebec Ministry of Transport was contacted regarding blocks of concrete falling onto Autoroute 19 from the Concorde Boulevard overpass above, a patroller was sent to do a sight and sound test to gauge whether the road should be closed and to clear away the concrete hazards; this was 30 minutes before the collapse. Neither roads were closed as the official concluded that the bridge presented no immediate danger. The patroller however did demand that an inspection be carried out as soon as possible, but was told "that an inspector would show up only on Monday, two days later".
The Ministry also sent out messages to journalists and traffic reporters warning of the concrete debris; this was confirmed by Josée Seguin, a spokeswoman for the Ministry.
The overpass on the Boulevard de la Concorde (Concorde Boulevard) was built in 1970 and was expected to have a life span of 70 years, of which it only lasted 36. David Lau, as part of an article for the Ottawa Citizen, suggests that this estimation of 70 years was inaccurate. They underestimated traffic volumes; they also did not take into account that "the amount and weight of trucks [on] today's roadways are significantly higher". He noted, "30 or 40 years ago, engineers could not anticipate the traffic some of their bridges would be forced to accommodate in the coming decades".
The design of the overpass was considered innovative at the time; however, this design made it nearly impossible to inspect thoroughly, as the entire deck would have had to be removed for such an inspection.
Michel Després (Transport Minister of Quebec) stated that it was inspected once a year, and got a more in-depth inspection once every three years, as per the usual inspection requirements in Quebec, last being May 2005. Ken Bontius, a civil/structural engineer at Hatch Mott MacDonald adds that the bridge was examined bi-annually by structural engineers.
After the collapse of the overpass, the government moved quickly to rescue survivors, remove the dead, and clear away the debris. The Ministère du Transport du Québec (MTQ) immediately requested that any overpasses of similar design in Quebec be identified. Of several such overpasses, only the de Blois overpass adjacent to the collapsed overpass was confirmed as similar. Indeed, this overpass was built in the same construction project as the de la Concorde overpass and was later found to have had the same flaws. It was closed to traffic less than three hours after the collapse and subsequently demolished.
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De la Concorde overpass collapse
The De la Concorde overpass collapse occurred at a bridge over Quebec Autoroute 19 in Laval, Quebec, Canada, at midday on September 30, 2006. On that Saturday, around 12:30 pm, the centre section of the south lane of an overpass (65-foot or 19.8-metre section of a three-lane overpass) collapsed in Laval, a suburb of Montreal, on Boulevard de la Concorde running over Autoroute 19. The collapsed section crushed two vehicles under it, killing five people and seriously injuring six others who went over the edge while travelling on the overpass. The north-lane half, along the same bridge, did not collapse. The autoroute was closed for almost four weeks, "disabling an important north-south link between Montreal and its northern suburbs as well as the Laurentian region".
A number of people had noticed that the overpass was not in good shape:
When the Quebec Ministry of Transport was contacted regarding blocks of concrete falling onto Autoroute 19 from the Concorde Boulevard overpass above, a patroller was sent to do a sight and sound test to gauge whether the road should be closed and to clear away the concrete hazards; this was 30 minutes before the collapse. Neither roads were closed as the official concluded that the bridge presented no immediate danger. The patroller however did demand that an inspection be carried out as soon as possible, but was told "that an inspector would show up only on Monday, two days later".
The Ministry also sent out messages to journalists and traffic reporters warning of the concrete debris; this was confirmed by Josée Seguin, a spokeswoman for the Ministry.
The overpass on the Boulevard de la Concorde (Concorde Boulevard) was built in 1970 and was expected to have a life span of 70 years, of which it only lasted 36. David Lau, as part of an article for the Ottawa Citizen, suggests that this estimation of 70 years was inaccurate. They underestimated traffic volumes; they also did not take into account that "the amount and weight of trucks [on] today's roadways are significantly higher". He noted, "30 or 40 years ago, engineers could not anticipate the traffic some of their bridges would be forced to accommodate in the coming decades".
The design of the overpass was considered innovative at the time; however, this design made it nearly impossible to inspect thoroughly, as the entire deck would have had to be removed for such an inspection.
Michel Després (Transport Minister of Quebec) stated that it was inspected once a year, and got a more in-depth inspection once every three years, as per the usual inspection requirements in Quebec, last being May 2005. Ken Bontius, a civil/structural engineer at Hatch Mott MacDonald adds that the bridge was examined bi-annually by structural engineers.
After the collapse of the overpass, the government moved quickly to rescue survivors, remove the dead, and clear away the debris. The Ministère du Transport du Québec (MTQ) immediately requested that any overpasses of similar design in Quebec be identified. Of several such overpasses, only the de Blois overpass adjacent to the collapsed overpass was confirmed as similar. Indeed, this overpass was built in the same construction project as the de la Concorde overpass and was later found to have had the same flaws. It was closed to traffic less than three hours after the collapse and subsequently demolished.