SUDBURY, ONTARIO – The tracks show some deterioration, but it is the trestle crossing over Beatty Street that really troubles Jeff Walker.
“There’s some significant corrosion,” Walker, a civil engineering professor at Cambrian College, says as he inspects the base of a support column. “This entire vertical structure is the same. It’s not just one side (one column). That is definitely a weakness in the entire structure. Your bolts and nuts – the stuff holding it down – these have significant corrosion. This is worrisome.”
Walker stresses that while he is a structural engineer, he does not specialize in railways. As a professor, he knows his stuff, but emphasizes continually that a railway inspector really should have the final word on the state of the CN track that runs through the Elm West neighbourhood. With that caveat, he admits the cracks in the concrete pads, to which the support towers are bolted, are also concerning.
“There is some deterioration in the concrete – we’re getting some localized spalling,” he says. “It’s when the cracks get into the reinforcing steel that it becomes a problem. How deep these cracks go, I’m really not sure, but this could be coming to the point where they do have to do some remediation on it.”
At the base of the support column, the one rising along the western side of Beatty Street, piles of corroded metal – small shards and wedges the size of an adult palm – have collected like sawdust on the floor of a carpentry shop. The metal in those piles should be attached to the structure supporting the bridge overhead, not lying at its base. As we stand talking under the trestle, we easily pick off pieces of metal the size of maple leaves from the structure.
“We have lost some steel at the base, which is where I’d expect to see that, because water tends to pool there,” he says. “There is a fair amount of deterioration”¦ This should probably be assessed, because all the load from this particular column is coming down here, so the more metal you lose, the greater the stress on the (base) plate.”
I liken it, and he agrees, to lying on a bed of nails – the more nails there are, the less body weight (or stress) per nail. The fewer nails, the more stress on each unit.
“The more metal you lose, the more stress there is on that particular section,” he explains. “This may not be enough to jeopardize the entire section, but it should be assessed. It should be inspected. I don’t want to say it should be remediated immediately, but it’s owned by CN rail and they have their own engineers on staff that should do an assessment of this particular structure, particularly at the base. They should be looking at this particular structure. I don’t know if it’s a crisis right now, but it should be inspected.”
Walker estimates that at some spots on at least one column there has been a 25% loss of steel near the base plate (the part of the column that sits on the concrete foundation), which he deems significant. There is also a fissure, about three or four inches long, at the foot of that same column, where the vertical and horizontal planes should meet.
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