Yankton, S.D. (AP) Moving mountains is one thing. Moving a steel bridge is quite another.
The contractor for converting the Meridian Bridge from traffic to recreational use has been charged with the latter task, and the project manager with the South Dakota Department of Transportation (SDDOT) overseeing the process confirms that it is a challenging one.
“We want to make sure it is going to be safe for everyone involved in the process,” said Kevin Heiman of the SDDOT. “We have to lift up one end of the bridge, take off its footwork and put new shoes on. With that in mind, it’s going to be a very tense time.”
Put in more technical terms, the contractor, PCiRoads of St. Michael, Minn., will bring in 400-ton (303 t) crane jacks to lift the truss of the bridge 1 in. (2.5 cm) in order to replace 12 bearings. Because the lifting will have to occur in several locations, the process could take up to six weeks to complete, according to Heiman.
“Currently, the bearings are rusted and frozen up, which prohibits the structure from proper expansion and contraction as the temperature changes,” he said. “We are required to replace those bearings so we have a stable structure well into the future.”
Design work on the lift process is still under way. If it goes smoothly, Heiman said PCiRoads is aiming to have the project done by the end of August.
“We’ll have to wait and see on the jacking process to make sure there are no delays,” he said. “When you’re lifting something of this magnitude, you never know if there are going to be any unforeseens.”
Work resumed on the $4.8 million conversion of the approximately 87-year-old bridge into a bicycling/walking trail in March. The contract called for the project to be complete by last Nov. 1. However, more steel deterioration was found on the bridge than expected, which required additional planning and work.
“We’re working with the contractor to deal with the unforeseen issues of excessive deterioration that required minor changes in the plan,” Heiman said. “Hopefully, we’re within a couple percent of [$4.8 million].”
The SDDOT is the lead agency overseeing the conversion, and the Nebraska Department of Roads is providing support.
Much of the work being done on the bridge involves reinforcing 36 interior and exterior gusset plates that have weakened over time. The last of those gusset plates was reinforced in April, Heiman said.
Once the bearings are replaced, the finger joints on the bridge also can be removed to make way for joints that will be more friendly for pedestrian uses. The current joints leave a divide in which feet or small tires could become lodged, Heiman explained.
Preliminary electrical work is expected to begin soon, as is installation of a handrail. The latter process will begin from the Nebraska side of the bridge.
“We’re hoping we’ll get this project completed this summer, so the citizens of this area can enjoy this landmark,” Heiman said.