Spectators lined the chain-link fence along the Parley’s Creek Bike Path east of 1700 East for most of the day Saturday to watch as Utah Department of Transportation crews replaced the bridge over Interstate 80. But those who planned to take in the action Sunday morning would have arrived too late.
It took UDOT crews just 3 ½ hours — and buckets of dish soap — to slide the new bridge into place after demolishing the old bridge Friday night. By early Saturday evening, cars and semi trucks were whisking under the giant American flag draped over the bridge even though I-80 had been scheduled to be closed until 1 p.m. Sunday.
“It just went faster and we had very, very few issues or concerns during the slide itself,” said project manager Becky Stromness. “Everyone was like, ‘This is just unbelievable. We haven’t seen that go that quick.’ So, we probably set the bar really high for the future. But I just look at it as a win for everyone.”
The process of building the bridge on-site and then moving it into place, called accelerated bridge building, was pioneered in Utah around 15 years ago. UDOT spokesperson John Gleason said the method, which is now used around the country, has been implemented 25 times in the state.
A time-lapse video released by UDOT shows most of the process. It begins with the destruction and clean-up of the old bridge, which was built in the 1960s. Then, the new bridge, which was built on-site slightly west of 1700 East, was slid into place.
“Oh yeah, there is a lot going on,” Stromness said. “It was actually a pretty big, coordinated effort, if you ask me, just to get all the equipment and materials and everyone just lined up and ready to go.”
Stromness said between 75 and 100 people worked on the project. Seven trackhoes were employed during the demolition, including four kitted out with jackhammer bits taking out the deck and girders, and three underneath to help with cleanup. She estimated more than 50 loads of debris were trucked away.
After the machines and crews cleared the path, finishing at least an hour ahead of schedule, the new bridge could be moved into place. That process began about 8 a.m., Stromness said. First, the new span was jacked up about 2 inches to allow a metal shoe to be placed under the supports. Under the shoes were placed low-friction, Teflon-coated pads greased with dish soap.
“The fun part in all of this is they’ve discovered liquid detergent is a really good lubricant,” Stromness said. “And so that’s what they lubricate with to try and get the least amount of friction and make it as slippery as possible.”
Then, by pushing against concrete rails placed along the path, a hydraulic pump moved the new bridge forward, about 6 inches at a time. Stromness said the pump, which was new, was able to move the bridge roughly twice as fast as anticipated.
Meanwhile, surveyors with GPS monitored the bridge’s path within a sixteenth of an inch.
After the structure was in place, the span was jacked up again about half an inch to allow the foot and pads to be removed. Then it was set on a heavy rubber mat.
Once crews filled potholes caused by the falling debris and repainted lines on the road, the interstate was reopened to traffic. Gaps remain between the bridge and the north and south stretches of 1700 East — around the east end of Sugar House Park and just south of Highland High — but Stromness said the goal is to have that repaired by 7 a.m. Monday.
“Our goal is to be open for school so everyone can get to high school,” she said. “We don’t want to make the kids tardy.”
The new bridge is wider than the old one. It will feature a 14-foot shared-use path on the west side, near the park. The east side will feature a 6-foot-wide sidewalk and a 6-foot bike lane.
For those who missed the bridge’s installation, there may be good news. UDOT plans to use the same process to replace the bridge over 1300 East as well. That project, Stromness said, is scheduled for the end of the year, possibly in October. Both bridges are among 175 projects scheduled for construction in Utah in 2022, with a total value of $2.5 billion.
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