The ramps leading to the seldom-used U.S. Highway 160 interchange near Farmington Hill, the so-called “Bridge to Nowhere,” are settling an abnormal amount and require repairs that are expected to start Monday, the Colorado Department of Transportation said.
The issues are at Ramp A, the one closest to Farmington Hill, and Ramp B, which connects to the bridge from a roundabout north of the bridge, which is designed to align with U.S. Highway 550, said Ed Archuleta, program engineer for CDOT Region 5.
Ramp A has settled about 6 inches and Ramp B 8 inches since construction was concluded in 2011, Archuleta said.
This has resulted in bumps where the ramps connect to the bridge, but no damage to the bridge itself, he said. “’We’re not seeing any settlement of the bridge itself, the superstructure, any of that.”
The settling has been uniform across areas where backfill occurred during construction and is a result of the geological makeup of the region and the prominence of Mancos Shale, said Mike McVaugh, CDOT Region 5 director. But the amount of settling is not something he has seen in his 20 years working in the region.
“We haven’t had a bridge settlement issue of this same magnitude,” McVaugh said.
Ramp repairs will include repaving the affected areas and repairing of wing walls on the north side of the bridge, he said. The cost is estimated at $400,000, including allowing for new problems that arise during the project.
“We put together a contingency of $400,000 just in case. If it ends up coming in a little under at $200,000, then that’s wonderful,” McVaugh said.
The money will come from a contingency fund made available by the State Highway Transportation Commission for projects of urgent need, he said. Additionally, some of the work will be covered by warranty under SEMA Construction, the contractor for the interchange.
Any excess funds will be returned to the transportation commission to be dispersed for other projects around the state.
While monitoring equipment shows that settling has slowed to less than half an inch a year, there is potential for additional issues going forward, McVaugh said. “There’s always that risk.”
Initial construction plans tried to accommodate for expected settling, Archuleta said. “We had a large fill. We just piled up dirt and let it sit there for a year to try and accelerate that consolidation, and we actually did.”
Soil samples were analyzed to estimate the amount of time needed for the consolidation of the soil, McVaugh said.
Those efforts appear to have not been enough, he said. “This could’ve been a situation where if we waited another month or two, maybe we would’ve gotten a little more settlement out of it, and we’d have been good, or maybe we just wouldn’t have gotten it. It’s hard to say.”
Construction was approved based on the analysis of the site, he said. “You’re trying to accelerate the project for the benefit of the public, but at the same time make sure you build it right.”
Interchange repairs are being done now because there is almost no traffic on the bridge, but traffic is expected to increase once Wilson Gulch Road is finished, said Lisa Schwantes, CDOT communications manager. “It’s a very small population that’s utilizing that interchange right now, because there’s really no reason to go up there at this point,” she said.
The Wilson Gulch extension will connect U.S. Highway 160 to the Three Springs area, and it should serve as the primary access for drivers traveling from the west once it is completed near the end of September, Schwantes said. The ramp work is expected to be completed in mid-September.
The extension also is important for emergency services to Mercy Regional Medical Center, McVaugh said. ”This is a critical access to the regional hospital, because right now the only way to get to the hospital is Three Springs signal light intersection.”
If there is an incident at the Three Springs intersection, access to the hospital is limited, he said.
Three Springs also stands to benefit from this Wilson Gulch Road.
“Bigger picture, longer term, it ultimately is going to allow for Three Springs to grow out. I mean we needed a secondary access point to do a complete build out,” said Tim Zink, real estate portfolio manager for the Growth Fund real estate group.
There has been growing interest in the commercial properties in Three Springs the last six months as the extension has neared completion, Zink said. “I can definitely say the commercial interest has increased from years past. Can I attribute it to the fact that Wilson Gulch is opening up? Probably not solely, but does that support? Yeah.”
Still, large commercial construction projects may not be attractive to businesses until the future realignment of Highway 550.
In spring 2015, the Federal Highway Administration signed off on a “Record of Decision,” which allowed CDOT to begin designing and seeking funding for the realignment of 550, McVaugh said. While there has been little headway since, Region 5 is pursuing funding for the project.
“Last fall, we put in for what they call Fast Lanes Freight Grant, which is a federal grant,” he said. CDOT asked for $100 million for construction of the realignment and expansion of 550 near Sunnyside to four lanes, in part to get the project some federal attention.
The organization did not receive the grant, which was not particularly surprising as it was in competition with proposals for higher traffic-volume roadways around the nation, McVaugh said.
No timeline for construction of the realignment has yet been set.
Luke Perkins is a student at Fort Lewis College and an intern with The Durango Herald. Reach him at firstname.lastname@example.org.