Cracks in the Crooked River Bridge get ODOT's attention
An inter-office memo recommends restricting load limit on the bridge as design options are investigated by state bridge engineersThe state Department of Transportation has officially warned that large working shear cracks in the Crooked River Bridge could lead to its closing if those cracks grow.
An interoffice memo from the Bridge Engineering Section cited recent inspections of the bridge The cracks are, the state bridge engineer noted, throughout the longitudinal reinforced concrete girders. If the cracks grow in length or width the engineers would recommend closing the bridge.
The cracks, according to State Bridge Engineer Mark Hiota, are not a public safety issue. "It wouldn't be in a memo if it were," he explained. "We wouldn't have taken the slow boat approach. We would have closed it down or at least posted it.
We've monitored the cracks for some time and noticed they are approaching the size when some action should take place. We think thing is going to be an issue someday, and so we need to have a plan."
The size of the cracks jeopardize the load carrying capacity of the structure, the memo states, severely reducing the concrete contribution to shear strength. There is adequate reinforcement, the engineers believe, to prevent sudden failure but the remaining fatigue of the steel is unknown.
The news of cracks in the city's all-important link out of town is not a new thing. Or as one ODOT official said, "not an overnighter." County Roadmaster Norm Thompson agreed, saying he has been working for a long time to get another way across the Crooked River. "They have been developing for as long as ten years. I've been fighting for at least that long to get a second crossing, but ..."
Possibly, the latest report on cracks in the bridge might might move long-range plans for a widening or a second structure to the more immediate future. County Judge Scott Cooper pointed out that he was made aware of the memo. "I have already made a pitch (for a new 4-lane bridge or a second bridge) and I got the same response from everyone; a knowing smile and a nod of the head."
Until repairs can be made to the bridge, ODOT's bridge engineers are recommending that no more single trip permits over the legal axle weight are issued and load weight be limited to 80,000 pounds maximum gross weight.
Thompson explained that restriction probably won't affect many companies. "Legal loads will be all right," he said. But "I called Frank Porfily (Owens Trucking owner) and told him if he is moving one of his cats he'll have to go out through Lone Pine and access Highway 97."
About the only other close bridge across the river would be to use the Elliot Road Bridge. That has a 42,000 pound load limit, Thompson warned, "Just enough for a school bus or an empty truck and trailer."
Gary Goodman, owner of Prineville Disposal Inc. said most of his garbage trucks heading for the county landfill should be okay. "It's (the 80,000 pound restriction) won't affect us hauling up to the landfill. Our trucks max out at about 46,000 pounds."
Concrete trucks, fully loaded, weigh on average about 70,000 pounds.
State bridge engineers will monitor the Crooked River Bridge on a daily basis while design options are being investigated.