Oakland Mills Walk Bridge temporarily closed
The Henry County Conservation Board has voted to temporarily close the Oakland Mills Walk Bridge until railings can be installed to narrow the path of traffic on the south side.
“It’s a Band-Aid approach to the problem. It would at least alleviate part of the safety concerns at this point,” John Klopfenstein, board member.
The decision to temporarily close the bridge came after a report at Monday’s conservation board meeting from Tim McDermott, lead inspector and engineer with VJ Engineering, who had been conducting an analysis of the bridge due to deterioration of some of the piers.
There is deterioration found on all parts of the bridge, but the southern portion is the worst.
The superstructure of the southern through truss span — which is above the water — is in serious condition due to a fatigue crack found on a fractured critical member.
“If it were to fail, the entire span very well could collapse,” said McDermott.
“If that crack that we found is a working crack, and it’s continuing to grow, that member will inevitably fail,” he continued. “If that does happen, the chances that span comes down is greatly increased.”
Also on the southern portion of the bridge, the stringer spans were found to be in critical condition, and most of the timber piers were significantly deteriorated.
“A few of them have rotted so severely that there’s barely a cross section left,” said McDermott. “I took a hammer and pounded all of the piles, and even some of the ones that look to the naked eye like they’re solid timber I found hollow ones.”
This significantly reduces the load-carrying capacity of the bridge, making it nearly half of what it should be. Iowa Code requires that bridges have a load capacity of at least 85 pounds per square foot (psf). The stringer span, with its deteriorated wood piles, rates at 49 psf. The south through truss span, with the fatigue crack, rates only 44 psf.
“Conventionally, you assign the worst case scenario to the entire bridge, so the bridge has a load rating of 44 pounds per square feet,” said McDermott.
Repairs on these portions of the bridge — along with various other repairs such as bringing the railing up to code and repairing general deterioration — could cost anywhere from $438,000 to $761,000, depending on how the board decides to proceed.
McDermott said that he understands that budgets can be tight, and if the board decides to proceed with just part of the repairs, he recommended repairing the crack and the timber piers as soon as possible.
“The most critical repairs that are in our report should be taken care of as soon as possible,” said McDermott.
The board briefly discussed closing the bridge altogether until the repairs could be made, but most were not in favor of that option.
“It doesn’t help us any to close that bridge,” said Jim Onorato, board member. “We can make minor adjustments to alleviate concern it could collapse on someone.”
The board decided to narrow the path on the southern span as a temporary fix to lessen the potential load on that portion of the bridge. Conservation Director John Pullis estimated it would take about a week for the department to install the railings, and until then the bridge will be closed.
“Until we get that stuff in place, it needs to be closed,” said George Jaques, board member.
Moving forward, Pullis said he will meet with County Engineer Bill Belzer to look at possible funding options and the conservation board will need to decide how to proceed.
In other business, the board approved proposed plans for a disc golf course at Water Works Park.
“I think it’s going to work perfect,” said Pullis, referring to the course map proposed by the disc golf league.
The plans call to expand the course into the Water Works Park area, adding an additional nine baskets. As each hole has an alternate spot, there will actually be 36 holes available.
Pullis estimated the cost of expanding the course to be around $5,000. However, he noted that it could be done for an Eagle Scout project, in which case the Scout would go out to find the funding.
Pullis also noted that John Shaw of Fort Madison is working on getting the course sanctioned as a PDGA (Professional Disc Golf Association) course, so that tournaments could be held.