Diefenbaker Bridge under the microscope
Inspection says 2011 repairs holding steading
The provincial government says Diefenbaker Bridge is in good shape and ready to handle increasing traffic volumes, provided it is properly maintained in the future.
On Monday, the government released the results of an analysis of the bridge conducted in November 2016 by ISL Engineering and Land Services Ltd. The analysis says repairs will have to be made in the near future, but overall the bridge is in working condition.
“While our analysis indicates that the fatigue life of the horizontal bracing connection may be coming to the end of its life, this does not mean the structure cannot continue to serve its purpose,” the report reads. “Its loading capacity is still adequate for the transportation of goods, and the Ministry has a number of options to keep the bridge in service.”
The report’s most important item was the state of repairs completed in 2011 to a major fracture known as a Constraint Induced Fracture (CIF). According to the report, the repairs are “functioning as intended and requires no further work.” However, there are other concerns.
Natural wear and tear make have accelerated due to what the authors of the report call “both poor detailing and bad construction practices.” Floor beams on the bridge were improperly fitted, which is placing a high amount of stress on the main girder. The report authors expect more cracks to occur “in the near future” as a result.
A spokesman from the Department of Highways said those problems likely stem from the bridge’s original construction period roughly five decades ago.
Other cracks were found, which are considered normal wear and tear for a bridge of this age.
Mayor Greg Dionne said it’s refreshing to know the entire bridge has been inspected, and was pleased with the response from the ministry.
“At one point they had a bridge inspection and the pillars weren’t done, and Coun. (Don) Cody brought that up,” he said. “It’s now obvious when you look at it that the bridge is repaired and in good shape.”
Dionne said any future repairs will be done at night to help decrease delays for motorists. Monitors will also be placed on the bridge to give a more accurate count of daily traffic numbers.
According to the report there is a lack of historical traffic data, which is needed to accurately predict future behavior. The new monitors will help fill that hole, especially when it comes to truck traffic.
Overall, the report says the impact of “overweight traffic” on the bridge has been minimal. A total of 944 semitrucks crossed the bridge over the past year. Roughly 24,000 vehicles cross Diefenbaker Bridge each day.
“While our analysis indicates that the fatigue life of the horizontal bracing connection may be coming to the end of its life, this does not mean the structure cannot continue to serve its purpose. Its loading capacity is still adequate for the transportation of goods, and the Ministry has a number of options to keep the bridge in service.” Excerpt from independent engineering analysis of Diefenbaker Bridge.
A recent inspection of Diefenbaker Bridge, pictured, shows that repair work done in 2011 is looking good, meaning the bridge should be usable well into the future.