Keystone Bridge rehab faces further delays, pedestrian access remains closed
By Willis Patenaude, Times-Register
The Keystone Bridge construction delay enters another week, and pedestrian access will remain closed for the foreseeable future on the recommendation of industry experts from Atkinson-Noland & Associates (ANA), who completed an assessment April 28-29. This was according to project engineer Nate Miller from Origin Design, who provided the most recent update to the Elkader City Council May 9.
Ongoing concern over the crack in the bridge arch revolves around the stability of the arch itself. Miller stated directly that it’s not possible to “say it’s a stable structure.” Additional concern arises from not being able to “predict how that arch will behave” should pedestrians be allowed to cross or if construction resumes on the bridge itself.
“The weight of the structure is the concern,” Miller said.
The assessment offered a solution, in the construction of a temporary shoring structure to stabilize the affected section of the bridge, which would allow construction and pedestrian access to recommence. However, this will lead to further delays and increased cost that will be absorbed by the city.
The process of building a shoring structure first has to go through the design phase, which comes with an estimated price tag of $20,000. The Elkader Council unanimously approved paying for it, though they capped the cost at that figure, partly because an actual estimate has not been received, but not for a lack of trying.
As Miller explained, the contractor, in this case Moyna & Sons, has been in constant contact with several design firms, but has yet to secure one for the project, although Miller suggested a “tentative firm” was on board.
In the meantime, the council approved the money based on a rough estimate that wasn’t provided by an actual design firm, and while doing so, openly acknowledged the price could end up slightly higher, which would lead to another vote. Likewise, the price could be cheaper, but this is currently unknown.
It should be noted this $20,000 only covers what Miller described as “construction drawings.” It will not cover any of the actual building and tearing down of the shoring structure. That will require another construction firm, to which the task will be delegated, but cannot be done until a design is created so the best option can be chosen.
Again, Miller affirmed Moyna & Sons has a list of companies that do shoring structure work, so finding one should not be difficult, but the lack of a design has slowed the process.
One certainty, though, is that the shoring structure will come with a hefty cost, in part because it is being constructed out of steel, which according to Miller there is a shortage of. Miller could not offer a cost estimate, only stating it “won’t be a cheap thing.”
That not-so-cheap thing will almost certainly cut into the city’s $180,000 contingency budget for the rehab project. There was a consensus among council members, mayor Josh Pope and city administrator Jennifer Cowsert that the contingency budget will be surpassed at some point in the coming months, or even weeks.
What this means is that a project that was fully funded is no longer, and the additional costs are passed on to the city.
Another aspect driving up costs and delays is the bridge itself—the “wholly unique structure,” as Miller put it. In conjunction with it’s age and the fact it’s made of limestone means the Keystone Bridge requires more specialized experts and solutions. Whereas other projects might already have a solution template for a shoring structure, “there is no copy and paste method,” for this bridge, Miller stated. And there is no timeline on when this structure will be completed or how long it will need to remain.
The shoring structure itself, once completed, will measure about five feet and fully support the southern arch and spandrel wall and remain until the arch is stabilized.
When it comes to the actual repair of the arch, Miller stated several options are being considered, but did not elaborate. He, along with the contractors, had a meeting Tuesday to discuss the plan moving forward and gather more information about possible repairs, costs and the current timetable.
In an interview after the meeting, Miller was asked whether this could’ve been prevented had the city rehabbed the bridge sooner, but like many things with the project, that question remains an unknown.
“It’s hard to say because of the age of the structure,” Miller said.
Concerning the crack itself, after investigating the cause, Miller couldn’t confidently answer why there was movement, but speculated a likely cause was the overall deterioration of the limestone and the condition of the masonry.
Regardless of the cause, the rehab project, which was scheduled to be complete in October, will not meet that deadline. According to Miller, it will most likely be closed over the winter and stretch into next year.
