The planned finalization of a bridge over Denali Park Road is now delayed. Denali Park Road has been delayed from 2025 to 2026. The road that runs for 90 miles into Denali National Park remains closed near the halfway mark, at which point it runs across a landslide driven by melting that has destroyed the road.
Denali National Park public affairs officer Sharon Stiteler says the new timeline is caused by an issue with geotechnical engineering.
“The excavation of more clay predicted on the west side of the project” she added. “Originally it was thought that there could be thirty cubic yards clay to be sifted however, now it appears it will be 80,000 cubic yards and that’s a huge shift.”
The bridge of 475 feet — estimated to cost $100 millionis set to be a bridge that will span a melting glacier located in Polychrome Pass that crosses the gravel road at the mile-marker 45. The road will be closed in 2021 when the landslide began to move at a rate that was too fast for maintenance workers to keep pace with.
“It reached the point where they had to calculate the distance they would have to travel to collect the gravel, and how long it would take to travel here, and how long it would take in order to keep the road, and also make it safe for drivers to cross,” Stiteler said.
The Park Science and Resources team head Dave Schirokauer underscores the challenging alpine terrain that the portion of Park Road traverses, and how it has changed since the road was constructed.
“They likely didn’t realize they constructed a road on the rock glacier. It was totally inactive at the time and was not an issue until 2016. From 1930-2016 it was a fantastic road with just a amount of warming in the climate that happened in that period and the disruption of cutting a cut the glacier, really woke the glacier.”
Bridge project engineer, Park Engineer Steve Mandt underscored the scope of the bridge project.
“Just an enormous amount of engineering, detail as well as thought go in this” the engineer said.
Mandt proposes a plan that calls for the gradual construction of the bridge truss-style across the slide, without any support.
“Starting with each of the eastern and west and working toward the center. So they’ll at some point build a bridge out in space, suspended over beneath the valley” the man said.
The thermosiphons that disperse heat will help protect the rock from freezing. the bridge’s abutments located to either end of the slide.
Construction on the bridge was originally scheduled to begin in May, however it has been delayed until July. Contractor for the bridge Granite Construction began mobilizing in the park in spring, and is currently in the process of constructing the 50-person camp in the gravel pit located at mile 27 along the Park Road.
