News

SH 133 South of McClure Pass - Fully Closed

May 6, 2013 - Northwestern Colorado/CDOT Region 3 - Following Rockfall Incident, Rock Scaling This Week on SH 133 Near Paonia Reservoir. (Travelers from north can still get to Marble and points south)

PITKIN/GUNNISON COUNTIES – Colorado Department of Transportation rockfall contractor Yenter Companies begins rock scaling today on SH 133 south of McClure Pass (mile point 29, just north of Paonia Reservoir). This work is in response to a rockfall incident that happened yesterday, Sunday, May 5.

At 9:30 a.m. on Sunday, May 5, CDOT closed SH 133 about 13 miles south of Mc Clure Pass summit after several large rocks came down onto the highway and into the ditch. CDOT rockfall specialists arrived on scene, along with experts from Yenter Companies. About seven or eight large rocks came down, with a cumulative measurement of 120-feet long by 50-feet wide by 20-feet tall. The biggest rocks measured about the size of a dump truck (30' by 15' by 10') and another was about 20' by 20' by 10'. There is also damage to the roadway; at least one of the rocks caused a depression in the pavement that is about 2' deep by 12' long by 10' wide.

SLOPE STABILIZATION AND REPAIRS: Yenter will be scaling rocks from the hillside today and tomorrow, and likely Wednesday as well. Scaling consists of climbing the hillside, anchored by safety ropes and prying some of the rocks loose (where possible) with pry bars. Additional scaling will be done with the use of air bags inserted behind loose rock, inflated until the rock breaks free.

Once it is determined that the hillside is stable, crews will blast rock on the roadway and haul it away. It is possible this could happen Wednesday or Thursday—all work is expected to last at least through this Friday.

DETOUR – The closure barricades are at MP 28 on the south side and MP 29.5 on the north. Motorists from the south attempting to get from Paonia to Carbondale, Glenwood or Aspen will need to detour onto SH 92, SH 65, I-70 and the SH 82 - a detour of about 140 miles. (Motorists from the north will use this detour in reverse). CDOT will post updates on this closure at www.cotrip.org (see “Travel Alerts”).

ONGOING PROJECT NORTH OF SUMMIT: CDOT’s separate project (with contractor TK Mining) is still underway north of the summit, between MP 44 and 49 (near Marble, at MP 45). At this site, during periods of rock scaling work (done each day), traffic will be stopped in both directions for up to 20 minutes. Delays may exceed 20 minutes as traffic queues are cleared in both directions. When scaling is not underway, travelers should still anticipate some delays and single-lane, alternating traffic, Monday through Friday (and some Saturdays) during daylight hours.

“McClure site is ranked at the top of our Rockfall Hazard Rating System,*” said Ty Ortiz, CDOT rockfall specialist. “The amount of rockfall we see here on an annual basis is quite a bit higher than what we see in many other sites around the state.”

On April 27 2007, a similar large-scale rockfall incident occurred at this mile marker that closed the highway for several days. CDOT and Yenter scaled, blasted more rock from the hillside and conducted follow up stabilization work. This May 5 incident brought rock down from further above. The geology in this area is sandstone on layers of shale, which attributes to the larger-scale incidents.

*CDOT’s Rockfall Program

The Colorado Rockfall Hazard Rating System (CRHRS) sites are ordered in funding priority from 1, which has the highest combination of hazard and risk, to 756 which has the lowest. To determine which sites are of high priority, several factors are analyzed including slope profile, geological characteristics and traffic data.

The rockfall program, started in 1996, was created to track rockfall information, implement a rating system and mitigate potential hazardous areas.  When the program first began, CDOT received just $750,000 for projects statewide. Since that time, funding for the Rockfall Program steadily increased to accommodate rising construction costs and allow for additional mitigation across the state. In recent years, the program was receiving $3 to $5 million per year. For the 2012-13 seasons, the program is receiving about $7 million—which includes $2 million in State Transportation Commission contingency funds that will help supplement projects statewide.

Since the program began, about 70 sites have been mitigated through CDOT’s Rockfall Program.  CDOT rockfall specialists also provide additional assistance at nearly 30-40 locations statewide each year in response to rockfall and other activity.

For information on CDOT projects statewide, the public may log on to www.cotrip.org or call 511. Better yet, sign up for highway updates by going to www.coloradodot.info and choosing the green cell phone icon in the upper right corner. Thank you for going Slow for the Cone Zone!

Please see photos at:http://www.coloradodot.info/news/media-room.html

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