48 Ave bridge project delayed due to error
City of Camrose manager Malcolm Boyd looks at the walking path on the new 48 Avenue bridge that will have to be reconfigured on Thursday. Josh Aldrich/Camrose Canadian
The completion of the 48 Avenue bridge will be delayed by about a month.
Planners did not include space for a gutter in the design of the new bridge and the error was not picked up until recently. This left the bridge too narrow by two metres. The solution is to take the needed space from the south side walk way, which will require swapping out two girds as the curb for the walk way is tied into the girders.
City of Camrose director of engineering Jeremy Enarson unveiled the error during a media and council walk through of the construction site on July 26.
"It should have been addressed was back before the design was finalized," he said. "We first really realized it when ... the bases for the signal lights were poured at 53 Street. That's when we sat down and took a look at where the existing curb line was and the locations of the bases and it looked like the curb was going to go right through the middle of the base."
The bridge is a total of 36.6 metres wide with seven lanes — four northbound and three southbound. Each lane is a standard 3.7 metres. The original plan called for a four-metre wide walkway on either side of the bridge to help move pedestrian traffic.
The revised plan calls for the left and right lanes in each direction to be widened by half a metre to allow space for the gutters that will run next to the walkways and along the centre median.
City of Camrose administration and engineers looked at other options, including sawing off the old curb and reforming it two metres over. However, because the curb is tied into the girder system, they did not want to negatively affect the structure of the bridge, a project that has a lifespan of 50 to 60 years.
"The way these girders are designed, the have some pre-stressed strands steel in there, so you can't just drill down to anchor your curb in there because you might damage the girder," said Enarson.
The bridge was already delayed by a couple of weeks in construction due to weather and other issues. The project was originally expected to be finished by the end of August but was on schedule to be finished in mid-September. Enarson was unsure of how long a delay the alterations would cause, but it likely means the project will likely be pushed back into October.
The other concern was the budget and how much added cost moving the girder would add onto the project. That was unknown at the time as well. The budget did include a $400,000 contingency.
The bridge came with an original budget of $8 million, but was dropped to $6.7 million when the project was awarded to project engineers Wood Environment and Infrastructure Solutions (formerly AMEC Foster Wheeler) and contractor PSA Construction Inc. As of the tour, approximately $4,494,300 had been spent.
There is also a built-in site occupancy agreement that will cost the contractors money for every day beyond the agreed upon completion date that they are on site, so long as the City is not at fault.
"When there are issues, such as oversight in design, legitimate reasons that the project is delayed then obviously the contractor does not lose money for those particular days," said Enarson. "It's a calculation that our consultants help us with so that we can understand where there's a credit back to the City where there's a credit back to the contractor."
The bridge replaces the former 50-year-old bridge that had reached the end of its lifespan. The bridge has also been widened by one lane in each direction as the City plans for the future. There is also a pedestrian walkway that goes underneath the bridge on the east side of the water that will connect the pathways around Mirror Lake and Legacy Park.
Mayor Norm Mayer was on hand for the tour and liked what he had seen of the project.
"I'm pleased with the way it is going to look when it is finished," he said. "I can envision the landscaping and the finished product, I think we'll be very proud of it."