Tunnel crack is no easy repair
denver & the west
Tunnel crack is no easy repair
GLENWOOD CANYON CLOSURE
By Nancy Lofholm
Denver Post Staff Writer
The Denver Post
Article Launched:
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.
Given the rock-dropping nature of the canyon, where boulders occasionally have punched holes in the 12.5-mile-long roadway and slides have covered lanes in other locations, workers on the crack-repair project will have a spotter with a bullhorn.
Elsen said the engineers will be working over the next week to find ways to shorten the repair time that will necessitate that drivers use 2 1/2 miles of two-lane road, but he and other highway officials aren't making any promises. About 17,000 vehicles pass through the tunnel each day.
"Certainly it's going to put some inconvenience on the traveling public," said CDOT spokeswoman Nancy Shanks, who noted that one lane of the westbound lanes will have to be temporarily closed any time equipment is brought out of the large bay inside the traffic-management complex.
"They will do their best to minimize the impact," she said.
The impact isn't easy to get around. The only highway options circumventing the canyon are a more than 250-mile jaunt to the north through Steamboat Springs and Craig or a more than 100-mile detour south through Leadville and over Independence Pass, which is still closed by snow.
So travelers put on hold by the crack may as well relax their grip on the steering wheel and take a better look at a piece of interstate that melds 60 million pounds of steel and 1.62 billion pounds of concrete into canyon-hugging expanses.
The project was the final four-lane link in the Western interstate system when it was completed in 1992. It has been honored as one of the most environmentally sensitive highway projects in the country and has won more than 30 engineering and design awards, including what is considered the Oscar of highway awards - the Outstanding Civil Engineering Achievement Award - in 1993 and the Presidential Design Award in 2000.
Staff writer Nancy Lofholm can be reached at 970-256-1957 or nlofholm@denverpost.com.
All contents Copyright 2007 The Denver Post or other copyright holders. All rights reserved.
This material may not be published, broadcast, rewritten or redistributed for any commercial purpose.
Tunnel crack is no easy repair
GLENWOOD CANYON CLOSURE
By Nancy Lofholm
Denver Post Staff Writer
The Denver Post
Article Launched:
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.
Given the rock-dropping nature of the canyon, where boulders occasionally have punched holes in the 12.5-mile-long roadway and slides have covered lanes in other locations, workers on the crack-repair project will have a spotter with a bullhorn.
Elsen said the engineers will be working over the next week to find ways to shorten the repair time that will necessitate that drivers use 2 1/2 miles of two-lane road, but he and other highway officials aren't making any promises. About 17,000 vehicles pass through the tunnel each day.
"Certainly it's going to put some inconvenience on the traveling public," said CDOT spokeswoman Nancy Shanks, who noted that one lane of the westbound lanes will have to be temporarily closed any time equipment is brought out of the large bay inside the traffic-management complex.
"They will do their best to minimize the impact," she said.
The impact isn't easy to get around. The only highway options circumventing the canyon are a more than 250-mile jaunt to the north through Steamboat Springs and Craig or a more than 100-mile detour south through Leadville and over Independence Pass, which is still closed by snow.
So travelers put on hold by the crack may as well relax their grip on the steering wheel and take a better look at a piece of interstate that melds 60 million pounds of steel and 1.62 billion pounds of concrete into canyon-hugging expanses.
The project was the final four-lane link in the Western interstate system when it was completed in 1992. It has been honored as one of the most environmentally sensitive highway projects in the country and has won more than 30 engineering and design awards, including what is considered the Oscar of highway awards - the Outstanding Civil Engineering Achievement Award - in 1993 and the Presidential Design Award in 2000.
Staff writer Nancy Lofholm can be reached at 970-256-1957 or nlofholm@denverpost.com.
All contents Copyright 2007 The Denver Post or other copyright holders. All rights reserved.
This material may not be published, broadcast, rewritten or redistributed for any commercial purpose.
posted by Walking Contradiction at 4/08/2007 05:21:00 PM
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