March 8, 2010

Rockfall in Glenwood Canyon

I-70 closed to all traffic in both directions between Glenwood Springs and Dotsero

GLENWOOD CANYON – Just after midnight, on March 8, a large rockfall incident hit I-70 in Glenwood Canyon, near mile marker 125 just west of Hanging Lake Tunnel. (The rockslide on Thanksgiving Day, November 25, 2004, was in the same general area, though rocks came from a different location on the hillside.)

I-70 is closed in both directions to all traffic at Glenwood (mm 116) and at Dotsero (mm 133). While there is no estimate for a re-open time, Colorado Department of Transportation will blast and break up larger boulders today and continue work to assess when a portion of the roadway may be opened for travel. CDOT will implement emergency contracting procedures and meet with contractors over the next couple of days as crews develop repair plans.

It is estimated that this slide brought 20 boulders onto the interstate, ranging in size from 3 feet to10 feet in diameter. The largest is estimated to weigh about 66 tons. The rocks have made holes in the elevated sections of roadway—the largest being in the westbound lanes (closest to the hillside) and measuring 20 feet by 10 feet. Another hole in the lower eastbound lanes measures 6 feet by 6 feet. There are a half a dozen other holes and “dips” in the roadway, as well as areas where rocks are embedded. Most of these repair areas appear to be approximately 5 feet by 5 feet. Rocks are scattered over 100 yards of roadway. Also damaged are three sections (about 120 linear feet) of steel guard rail and 100 linear feet of median barrier. The damage is similar to that resulting from the 2004 rockfall incident.

ALTERNATE ROUTES: from westbound I-70: exit at US 40/Empire to State Highway 13 and back to I-70; exit in Silverthorne and take State Highway 9 to US 40 and State Highway 13; exit at Wolcott/State Highway 131 to US 40 and State Highway 13. From eastbound I-70: exit at Rifle/State Highway 13 to US 40 and back to I-70. Travelers may also wish to use US highways 160, 285 and 50 if traveling to destinations south.

I-70 is not expected to open any time soon. CDOT appreciates the patience of travelers and want everyone to be assurred that crews are doing everything possible to get the roadway safely open to traffic. Video of the rockfall site can be found at http://www.cotrip.org

Subject: I-70 Glenwood Canyon Rockfall Update: March 8, 2010 at 3 p.m

CDOT geologists are on site and are in the process of assessing a rock that appears to be unstable. The assessment requires a two-hour hike up the mountain, inspection and a two-hour hike back down. If the rock is determined to be unstable, CDOT will not reopen any lanes of I-70 until rockfall mitigation can be conducted. Since the assessment will take several hours to complete, mitigation work will not take place until tomorrow as it will be unsafe to conduct the work at night. In the meantime, crews continue to blast the large boulders into smaller pieces for removal (photo attached). So far, crews have blasted three rocks and have several more to blast apart. This work will continue this afternoon.

I-70 remains closed in both directions between Glenwood Springs (mm 116) and at Dotsero (mm 133). Motorists can take US 40 to SH 13 as an alternate route. US 50 to the south is now closed over Monarch pass due to adverse conditions.

More information will be released following inspection of the rockfall site.

UPDATE 6:37 PM, MARCH 8
CDOT crews are completing work for the night – conditions are now too dark. I-70 will remain closed overnight.
CDOT geologists have determined that the rock above the highway is too unstable to remain in place. Early tomorrow morning, Tuesday March 9, rock scaling crews will be meeting to determine how best to mitigate the rock.

CDOT maintenance crews made great progress breaking up and clearing away the boulders today. We will send notice as soon as we receive details of the mitigation work. Crews are working fast and making every effort to get traffic safely flowing through the canyon again.

UPDATE 8:30 AM, MARCH 9
Crews have begun their hike up the hillside in Glenwood Canyon and will begin rock scaling by around 10:00 A.M. They will start scaling above the unstable rock and work towards it with the goal of prying it loose and/or gaining a better understanding of its stability. The rock is approximately 20 feet in diameter.


Posted 3/8/10 3:00 pm


Posted 3/9/10 8:30 am

UPDATE: 2:00 PM
Scaling is still underway. We will know much more when work is complete later this afternoon. We will send any information we might have regarding possible re-open times as soon as possible.

Update from CDOT:

A team of six hiked up 900 feet on the mountainside today and conducted rock scaling operations (removing loose rock material with pry bars and other equipment) until approximately 5:30 p.m. They were able to safely access the unstable rock needing to be brought down. Losing daylight, crews attempted to pry sections loose and locate areas in which to effectively place and then charge explosives, but were unable to do so. Tomorrow, March 10th, crews will hike up to the location once again and drilling and other equipment will be airlifted by helicopter to the site. Drilling and blasting as well as other mitigation efforts will be used to bring down the rock. Due the challenging nature of the project, it is difficult to estimate when the mitigation work will be complete and when I-70 may reopen. Should the rock be brought down successfully, causing minimum damage to the highway, crews could then begin repairs to the eastbound lanes in preparation of opening one lane in each direction using the eastbound lanes. Please note that the process to reopen the Interstate is dependent upon the completion of the mitigation work. An update will be sent mid-morning on March 10th.

Per CDOT 10:40 a.m. 3/10/10:

The helicopter is on scene—ready to drop off drilling equipment and a generator for planned drilling/blasting operations. If all goes well, crews anticipate bringing the boulder down early afternoon. When the boulder is down, the hillside scaled and stabilized, and any resulting highway damage is assessed, we can begin to send information regarding estimated highway re-open times. We will send notice as soon as the boulder is down.


Posted 3/10/10 10:47 am


Posted 3/10/10 10:47 am

CDOT UPDATE: 6:40 PM, MARCH 10, 2010

Crews blasted the large rock just before 6 PM. CDOT maintenance crews immediately began work to clear the debris on the highway. They have worked throughout the day making the repairs necessary to open a lane of traffic in each direction when rockfall mitigation is complete. Because daylight is fading, the highway will not open tonight. Crews will hike to the site tomorrow morning to conduct follow-up rock scaling and assess the stability. CDOT will make every effort to get some portion of the interstate open to traffic tomorrow, March 11. Be assured we will send an update as soon as we begin any procedures to open a lane.

CDOT UPDATE: 8:10 PM, MARCH 10, 2010

Our geologists returned from the rock mitigation site safely and were very satisfied with the work that was accomplished today. With the blasting, there was a clean break of the rock from the slope and all of the rocks we were concerned about were knocked down. As a result, mitigation work will not be required tomorrow. Since the blasting brought down additional rock, crews will have some cleanup work tomorrow along with drainage work and final pavement repair. The good news is that one lane of eastbound and westbound I-70 will reopen by the end of the day tomorrow. We will keep you posted as we get close to a reopening time.

CDOT UPDATE: 8:45 AM, MARCH 11, 2010

CDOT Maintenance crews began clearing snow in the canyon early this morning and are now beginning work to make the repairs necessary to open a single lane of traffic in each direction today. They are clearing rock debris from all lanes (the blast brought down some dozen larger boulders (4 feet) and many smaller rocks), making repairs to the drainage system and completing roadway patching in numerous places. Crews have already set up traffic control cones/barrels and signage on the Interstate so that when repairs are complete, the highway can open quickly. We will send notice as soon as a re-open time is set today.

CDOT UPDATE: 3:10 PM, MARCH 11, 2010

CDOT crews have opened I-70 through Glenwood Canyon in both directions. Traffic is reduced to one lane in each direction and will remain like this until long-term repairs can be completed in the coming weeks/months. The speed limit has been reduced to 40 MPH and load over 14-feet wide are restricted from traveling through the work area. CDOT wants to thank motorists and impacted communities for their patience during this time. More information to come tomorrow afternoon on repair plans.

Date: March 12, 2010

CDOT Announces Apparent Low Bidder for
I-70 Glenwood Canyon Rockslide Damage Repairs

Emergency contracting procedures help engineers
expedite process, get work underway quickly

GLENWOOD CANYON – Following the rockfall that hit I-70 early (around 12:05 AM) on Monday, March 8, CDOT immediately implemented emergency contracting procedures to get a contractor on board for the extensive repairs that would have follow. As early as Monday afternoon, CDOT engineers met with one prospective contractor on site, then provided site tours to four more on Tuesday.

“This happened on Monday, but we were able to get the work designed and out for competitive bidding by Tuesday, advertising the work to contractors on Wednesday” said CDOT Program Engineer Joe Elsen. “We opened bids at 2 PM today and now, with an apparent low bidder identified, we are all very happy to begin the repairs. ”

The apparent low-bidder is Flatiron Construction. The total construction cost for the repair project will total $860,417. Flatiron has committed to completing the project in 55 days. The total cost of the rockfall event is expected to be much higher as the contruction cost doesn't include emergency response, blasting, etc. needed to open the highway. These figures are still being totaled.

It is estimated that this slide brought 20 boulders onto the interstate, ranging in size from 3 feet to10 feet in diameter. The largest is estimated to weigh about 66 tons. The rocks have made holes in the elevated sections of roadway—the largest being in the westbound lanes (closest to the hillside) and measuring 20 feet by 10 feet. Another hole in the lower eastbound lanes measures 6 feet by 6 feet. There are a half a dozen other holes in the roadway, as well as areas where rocks are embedded. Most of these repair areas appear to be approximately 5 feet by 5 feet. Rocks are scattered over 100 yards of roadway. Also damaged are three sections (about 120 linear feet) of steel guard rail and 100 linear feet of median barrier. The damage is similar to that resulting from the 2004 rockfall incident.

Elsen added, " I want to thank Roland Wagner, CDOT's resident engineer in Glenwood Springs for putting this project together in record time."

The repairs will most likely take place Monday through Friday, but some weekend work may occur depending on weather and project schedule. Further details regarding a start date, the work and subsequent lane closures will be sent when they become available.

Repairs begin at Glenwood Canyon
Rockfall Site Today

Contract set with an early completion incentive designed to expedite work

GLENWOOD CANYON – The Colorado Department of Transportation begins repairs today on damage caused by the rockfall incident on I-70 in Glenwood Canyon on March 8. Flatiron Construction Corporation of Longmont will be making the repairs. The cost of the repair project is approximately $860,000. However, the total cost of the rockfall event—including CDOT maintenance and design work—is expected to be much higher (that figure will be reported at a later date).

Because of the critical need to expedite repairs on the interstate, the contract carries with it a $5,000/day incentive for early completion (with $5,000 deducted each day the work runs past their set completion date). Flatiron Construction, in its bid package, set a completion date of May 15; the company can earn a maximum of $31,000 in early-completion incentives by beating this projected date.

The repair work is taking place between mile markers 124 and 125, just west of Hanging Lake Tunnel. The work will involve bridge deck and bridge wall/rail repairs (including 150 feet of new steel bridge rail); guardrail repairs (about 120 linear feet) to hillside concrete barrier; median concrete barrier repair (replacement of 400 linear feet); removal and replacement of 690 square feet of concrete retaining walls; straightening of steel bridge girders using a flame straightening process; some lighting and electrical repairs; and repairs to the bike trail below. Finally, the contractor will use approximately 500 tons of base course material on the roadway, as well as 400 tons of patching asphalt to repair the driving surface.

TRAFFIC IMPACTS: Work will be done during the day, Monday through Saturday. There will be a single lane of traffic open in each direction, but motorists may encounter occasional traffic stops, when safety or equipment mobilization warrant. The speed limit is reduced from 50 to 40 mph; delays should be very minimal. Motorists are urged to obey the reduced speed limit and maintain a safe following distance while driving through the work zone. There is a 14-foot width restriction. While the Glenwood Canyon bike path should open sometime in April, the section between the Shoshone power plant and Hanging Lake rest area will remain closed for safety until the project is completed in May. Thank you for going “Slow for the Cone Zone!”

ROCKFALL INCIDENT INFORMATION: Just after midnight, on March 8, a large rockslide hit I-70 in Glenwood Canyon near mile marker 125, just west of Hanging Lake Tunnel. I-70 was closed in both directions to all traffic between Glenwood Springs (mm 116) and Dotsero (mm 133). The interstate reopened to a single lane of traffic in each direction on the afternoon of Thursday, March 11.

The rockfall brought 20 boulders onto the interstate, ranging in size from 3 feet to10 feet in diameter. The largest weighed about 66 tons. The rocks made holes in the elevated sections of roadway—the largest being in the westbound lanes (closest to the hillside) and measuring 20 feet by 10 feet. Another hole in the lower eastbound lanes measured 6 feet by 6 feet. There were a half a dozen other holes and “dips” in the roadway, as well as areas where rocks were embedded. Most of these repair areas were approximately 5 feet by 5 feet. Rocks were scattered over 100 yards of roadway. Also damaged were three sections of steel guard rail and median barrier.

Rockfall Repairs in Glenwood Canyon
Are Now Complete, All Traffic Lanes Open

Prime Contractor Flatiron Construction Earns Full
Incentive for Early Completion


GLENWOOD CANYON – The Colorado Department of Transportation and contractor Flatiron Construction completed repairs with a final walk-through inspection this afternoon, May 19. Flatiron has beat the project completion date, initially set for May 15, but extended to May 31 when CDOT added wire mesh (rockfall netting) to the project.
Flatiron Construction Corporation of Longmont began the repairs on March 8. Because of the critical need to expedite repairs on the interstate, the contract carried with it a $5,000/day incentive for early completion (with $5,000 deducted each day the work runs past their set completion date). The maximum incentive is set at 5 percent of the contractor’s bid items, which totaled $620,830. Thus, Flatiron Construction has earned $31,000 in early-completion incentives by beating the May 31project completion date by 12 calendar days.
“I can’t say enough about the efficient, high-quality work that Flatiron has performed,” CDOT Region 3 East Program Engineer Joe Elsen said. “Even with the addition of rockfall netting and some weather challenges, the contractor expedited this project, maintained a safe work zone and delivered a successful project.”
PROJECT DETAILS: The repair work took place between mile markers 124 and 125, just west of Hanging Lake Tunnel. The work involved bridge deck and bridge wall/rail repairs (including 150 feet of new steel bridge rail); guardrail repairs (about 120 linear feet) to hillside concrete barrier; median concrete barrier repair (replacement of 400 linear feet); removal and replacement of 690 square feet of concrete retaining walls; straightening of steel bridge girders using a flame straightening process; some lighting and electrical repairs; and repairs to the bike trail below. Finally, Crews used approximately 500 tons of base course material on the roadway, as well as 400 tons of patching asphalt to repair the driving surface.
Flatiron Construction, with assistance from rockfall contractor Rock Solid Solutions, also installed 14,000 square feet of wire mesh along a section of the canyon wall, near the bottom of the two chutes that delivered the rocks on the March 8 rockfall event.
“The wire mesh is designed to keep smaller rocks (less than 3 feet in diameter) that may release from the talus slope above from reaching the highway,” CDOT Geologist Ty Ortiz said. “The goal is to reduce the chances of these smaller rock incidents; the mesh is not intended to mitigate a large event like the one that occurred on March 8.”
The costs of the rockfall incident and the repair project include the following:

* Rockfall Incident - $300,000 (maintenance costs, traffic control, blasting/scaling, helicopter)
* Construction Phase - $1,880,000 (including the additional $300,000 for the rockfall mesh)
* Total - $2,180,000


These costs will be reimbursed by the Federal Highway Administration. CDOT is also requesting additional federal assistance to conduct a follow-up selection study on additional rockfall mitigation in the canyon. More information on this will be sent at a later date when information is available.
“Rock Solid Solutions worked with us during the incident phase, with our initial scaling and blasting operations, and also with our follow-up work on placing the wire mesh,” CDOT Glenwood Resident Engineer Roland Wagner said. “Their expertise on this incident was invaluable—they deserve a great deal of credit for their incident management and timely response.”