Construction crews revealed Thursday that they found a vehicle-sized concrete block on the north side of the river, where the old downtown pedestrian bridge was removed.
“We don’t know why it’s there, obviously, because we would have done things differently with it,” said Will Edeen with TransEd, the company in charge of the LRT construction project.
“From a mass standpoint, we don’t know exactly the size of it … because it’s so deep and still below the riverbed,” Edeen said.
“It’s approximately the size of a car or bigger, to add a rough magnitude to how big this is.”
The concrete block was discovered while crews were doing foundation work for the new Tawatina Bridge. TransEd and City of Edmonton documents and prior geotechnical investigations did not identify an obstruction in that location, TransEd said Thursday.
It was an usual find, and crews said it will delay the opening of the new shared-use path, which was set to open in May 2019.
“Due to the nature of the location, because it is on the slope of Grierson Hill — and the size and magnitude of the item — you cannot just extract this because it leads to other consequences, both in safety and in environmental aspects to it,” Edeen explained. “We are working around the obstruction.”
Because the piece is below the riverbed, Edeen said experts from around the world have been on site since February to help develop a “safe technical solution.”
“These experts have worked on and managed cofferdam construction all over the world, in a range of environments including the ocean. They will advise on how to modify the cofferdam to allow for the safe excavation down to the required bridge foundation depth,” read a media release from TransEd.
A new timeline for when the shared-use path will open has not been revealed. TransEd said it “will be delayed past the original scheduled opening in May 2019.”
Firm timelines for the opening of the shared-use path are in place, as per the private-public partnership, which means penalties will be incurred. The City of Edmonton and TransEd would not say what those penalties might be.
It’s not yet known what, if any, extra costs will be incurred to deal with the extra work.