A large crack has opened in the Blue Ridge Parkway just north of Tanbark Tunnel at Milepost 374.5. Bill Sandersemail@example.com / /firstname.lastname@example.org
Asheville Citizen-Times (ACT) -- It's not the rippling mountain views. It's not the chance to spot a black bear or a waterfall. The newest tourist attraction on the parkway appears to be a giant crack in the asphalt.
The crack, running down the center line of the roadway just north of the Tanbark Ridge Tunnel and first noticed nearly two weeks ago, is now more than 300 feet long, more than 6 inches wide and several feet deep. The northbound side is a couple of inches lower than the southbound lane.
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A companion crack running along the edge of the slope on the road's shoulder is more than a foot wide in some places.
For those who can do the hike to see the crack, it's a hot ticket.
Sisters Emily and Maggie Anixter, of Haw Creek, walked two miles Wednesday from where the parkway is closed at Milepost 376 at Ox Creek Road just to see the crack, at Milepost 374.
The road is closed to vehicle traffic more than 20 miles, to Milepost 355 at N.C. 128 near Mount Mitchell State Park. It is still open to pedestrians and bicyclists until next week, when work on a temporary road fix begins.
"We came specifically to see the crack. It's kind of a big deal," Emily Anixter said, peering down into the deep hole that has opened up beneath the roadway. "We just wanted to make sure our parkway isn't falling off the mountain. It's impressive. It's the talk of the town."
A crew from the Federal Highway Administration began core drilling tests Wednesday to get to the root cause of the slope failure.
Engineer Mohammed Elias said the crew will drill five bores, which will each take about a day. The first was drilled Wednesday. Elias, who also worked on the recent slide project on Newfound Gap Road in Great Smoky Mountains National Park, said the parkway project is considered a priority.
"We are drilling to see what is the depth of the bedrock and what the type of rock is, to see the soil classification and the subsurface soil condition," Elias said.
He said he won't know the cause of the slope failure until all the testing is done, which includes seismic activity testing, but said it is likely due to the excessive rain in the past month.
Rainfall in Asheville for July has set a record, with nearly 12 inches so far. A normal July has about 3 inches of rain.
"The geometry of the slope, the type of material, the stability of the material, a combination of factors can contribute," Elias said. "This is probably water-related. Water contributes to slope instability. It could be a drainage issue, it could be rainfall."
Elias said after testing is done, engineers will develop a slope stability model, which will determine the cause of the failure. He said they can then present the parkway with alternative solutions for a permanent fix.
Parkway staff members say they are hoping to open the road, at least partially, while a permanent failure fix is underway. The parkway is the most visited National Park Service site in the country, with 15.2 million visitors last year. October and July are the busiest months of the year. In July 2012, there were 1.9 million visitors, and 2 million visitors in July 2011.
"The short-term, temporary repair will start next week, with the idea to take out the compromised material, establish a temporary road on the uphill side of road that will allow us to be open by Labor Day," said Mike Molling, parkway chief of maintenance and engineering.
"We'll be open for September and October, and as soon as we can complete the design, do a separate contract award for the project, then we'll shut down again and go about the business of making a permanent fix."
Caroline McCracken, who grew up in Asheville and now lives near Atlanta, was back in town visiting family with her children, Arthur Mills, 10, and Rachel Mills, 13. On Wednesday, she was enjoying the reprieve in motor traffic.
"I grew up driving on the parkway, but walking, you get to see things you wouldn't normally see, like a little waterfall off the Rattlesnake Lodge Trail," McCracken said. "And how many chances do you get to walk through the tunnel?"
But for McCracken's children, the highlight of the afternoon was definitely the hole in the ground.
"The crack is really cool," Arthur Mills said.