A crack in concrete above the main Glenwood Canyon tunnel on Interstate 70 is growing wider and worse than expected and will force multimillion-dollar repairs while the tunnel is closed all summer.
And it has turned into a major headache for the cadre of engineers and highway officials charged with fixing it.
"This one is tough," said Colorado Department of Transportation engineer Joe Elsen, who worked on construction of the much-lauded Glenwood Canyon roadway for 11 years and is now back as the program engineer for the crack repair.
The troublesome crack is above the eastbound lanes of the Hanging Lake Tunnel. It is in the ceiling of an empty wing of the five-story traffic-management center, which serves as the brains for a highway equipped with zoom video cameras, seismic sensors, pavement temperature sensors and satellite weather monitors.
But all those gizmos and the banks of computers that made Glenwood Canyon a model "smart highway" for other road-building projects couldn't outsmart a crack in the highway's nerve center.
The crack first was noticed in July during a routine maintenance inspection and has been monitored and measured every two weeks. In February, it began leaking water and widening.
Colorado Department of Transportation officials began putting funding into place, knowing a repair would be necessary. Several weeks ago, the crack widened more - it is now 70 feet long, 4 1/2 feet deep and 1 1/2 inches wide - and that set off a flurry of action.
Engineers in the past week have huddled over blueprints in an underground complex that also can serve as a safe haven for visiting presidents in the event of an emergency and as a lookout point for government agents monitoring terrorist activity. Engineers also have been getting helicopter views of the damaged area and the cliffs that dropped minivan-sized rocks onto the underground building, causing the crack.
CDOT has $2 million in hand for the repair and has used emergency measures to quickly hire a contractor. Already, bulldozers and other large earth-moving machines have been hauled into the narrow canyon by rail.
"We have 15 engineers here today, and, yes, they are busy," said junior foreman of the traffic-management center Greg Sullivan over a hubbub of voices Thursday.
All that rush is still not expected to get the eastbound tunnel back open before the fall. Workers must brace the cracked slab, install monitors in it, and move the behemoth rocks and about 30 feet of fill dirt. They need to dig down to get to and fill the crack. A new reinforced slab will then be placed above the cracked slab.
Elsen would not speculate on what might have happened without these repairs.
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And it has turned into a major headache for the cadre of engineers and highway officials charged with fixing it.
"This one is tough," said Colorado Department of Transportation engineer Joe Elsen, who worked on construction of the much-lauded Glenwood Canyon roadway for 11 years and is now back as the program engineer for the crack repair.
The troublesome crack is above the eastbound lanes of the Hanging Lake Tunnel. It is in the ceiling of an empty wing of the five-story traffic-management center, which serves as the brains for a highway equipped with zoom video cameras, seismic sensors, pavement temperature sensors and satellite weather monitors.
But all those gizmos and the banks of computers that made Glenwood Canyon a model "smart highway" for other road-building projects couldn't outsmart a crack in the highway's nerve center.
The crack first was noticed in July during a routine maintenance inspection and has been monitored and measured every two weeks. In February, it began leaking water and widening.
Colorado Department of Transportation officials began putting funding into place, knowing a repair would be necessary. Several weeks ago, the crack widened more - it is now 70 feet long, 4 1/2 feet deep and 1 1/2 inches wide - and that set off a flurry of action.
Engineers in the past week have huddled over blueprints in an underground complex that also can serve as a safe haven for visiting presidents in the event of an emergency and as a lookout point for government agents monitoring terrorist activity. Engineers also have been getting helicopter views of the damaged area and the cliffs that dropped minivan-sized rocks onto the underground building, causing the crack.
CDOT has $2 million in hand for the repair and has used emergency measures to quickly hire a contractor. Already, bulldozers and other large earth-moving machines have been hauled into the narrow canyon by rail.
"We have 15 engineers here today, and, yes, they are busy," said junior foreman of the traffic-management center Greg Sullivan over a hubbub of voices Thursday.
All that rush is still not expected to get the eastbound tunnel back open before the fall. Workers must brace the cracked slab, install monitors in it, and move the behemoth rocks and about 30 feet of fill dirt. They need to dig down to get to and fill the crack. A new reinforced slab will then be placed above the cracked slab.
Elsen would not speculate on what might have happened without these repairs.
more...
