The fraying Morrison Bridge needs work and—this time around—the county's doing the job itself.
Multnomah County announced this afternoon a series of lane closures on the bridge, aimed at identifying and swapping out polymer panels that have cracked and loosened worryingly in less than two years. And surprise! The work starts Sunday morning on the bridge's eastbound lane.
"The fiber reinforced polymer (FRP) deck that was installed on the lift span in 2011 – 2012 has shown signs of premature wear," the county says, in one of the only public acknowledgments of the bridge's problems to date. "Deck attachments for some panels have loosened."
Bridge engineers believed the new panels would make the span more safe when they were installed in 2011 and early 2012. Instead, as we've reported again and again, the fiber-reinforced polymer decking began failing almost immediately.
In response, the county entered into a court case assigning blame to the contractor that laid the deck and a supplier for shoddy workmanship and a defective product. The supplier, meanwhile, blames shoddy workmanship. And the contractor blames a defective product and the county.
Rather than trust the repair work to an outside outfit, the county has elected to do the work in-house, using a fastener called a
"huckbomb" (the county has clarified it meant "huck bolt") (ugh. that's not the case, either. It's a Huck BOM) instead of screws to secure the decking. Spokesman Mike Pullen said a forensic consultant will be brought in to help determine exactly what went wrong.
In all, the county plans six weeks of lane closures, and will inspect roughly a third of the bridge—replacing panels as needed. No word on when—or if—the remaining two-thirds of the bridge will be inspected.
One interesting question—and one Pullen couldn't immediately answered late on a Friday—is where the county has obtained the replacement panelling. Its initial supplier, a North Carolina company called ZellComp, Inc. is one of the only—perhaps the only—outfit supplying FRP panelling that will work on the bridge, county engineers have found. Yet the county's lawsuit accuses the company of supplying defective goods, and we've reported that some of the panels the company sent along initially contained worrisome defects.
County officials have estimated repair costs for the bridge will "exceed $2 million."
Anyway, about those lane closures. Hit the jump for the county's full release.
One eastbound lane on the Morrison Bridge will be closed for roughly three weeks starting at 7 a.m. on Sunday, January 26 to allow Multnomah County to begin an inspection of the lift span deck.
The fiber reinforced polymer (FRP) deck that was installed on the lift span in 2011 – 2012 has shown signs of premature wear. Deck attachments for some panels have loosened. County staff have monitored the deck surface regularly in recent months as a precaution. The inspection will allow county crews to remove each deck panel in the southernmost lane and inspect it for wear. Degraded panels will be replaced with new panels. All panels either replaced or re-used during the inspection will be re-attached to the deck with a huckbomb fastener that is expected to provide a more durable attachment than the existing screws.
A forensic engineering consultant is working with the county to analyze the worn FRP panels to determine the cause of the wear and the extent and method of repair needed. The county is pursuing litigation related to the FRP fabrication and installation by other parties.
The SW Naito Avenue onramp and the SE Water Avenue offramp from the bridge will remain open during the work. All freeway ramps will remain open also. On weekdays, the middle eastbound lane will be closed on the lift span from 7 a.m. to 3 p.m. for safety during the work.
After panels in the eastbound lane are inspected, the outside westbound lane will be closed for three weeks for a similar inspection. The county expects that information gained from these inspections will help define the extent and method of repairs needed for a long-term solution for the deck.
Multnomah County maintains the Morrison Bridge, five other Willamette River bridges, and 300 miles of roads. For more information, visit www.multco.us/bridges.