November 28th, 2011
REBUILDING SR-14Preserve Infrastructure, by Catherine Higgins.
A major landslide that closed State Route 14 put a massive rebuilding effort in motion at UDOT.
The substantial area of the slide, huge house-sized boulders and the geology of the area will present challenges to the contractor that will be chosen to rebuild the road. A team of UDOT engineers, along with local design and construction experts, will conduct preliminary investigations and use an innovative contracting method to accelerate the removal of the landslide material in a safe manner, re-establish the stream bed and construct a new road.
David Fadling, UDOT engineer and Lead Geologist, is working with a team of investigators to install monitoring equipment and take samples of the slide material for testing. “Our main concern is stability,” says Fadling. “If the slide is still moving, we would like to know the depth of the sliding.” Inclinometer casing will be installed to monitor lateral movement in the ground. Piezometers will be installed to help locate the depth of ground water in the area.
Fadling’s team will also investigate on site materials in order to to define material properties and to identify the sliding surface. “We suspect shale is the culprit weak layer on which sliding initiated and groundwater is almost surely a contributing factor.” Shale is a sedimentary rock with fine clay particles. The type of material and groundwater will be taken into account as engineers plan how to clear the landslide and build the new road.
Building the road will involve moving and compacting material to reestablish the road grade. Fadling anticipates that some of the large boulders may have to be blasted and moved with large bulldozers and some will be pushed or rolled down the hill. “The contractor will likely use gravity as much as possible to assist in moving large blocks of rock,” he says.
It is likely the material will be moved from the top of the slide and used to buttress the recovered road grade. Material used as sub grade for the road will need to be thoroughly compacted to guard against settlement.
UDOT’s uses a variety of contracting methods that factor in user costs, encourage innovation and speed, and seek a balance point for everyone, including the contractor and the general public. UDOT will use a Construction Manager General Contractor method for the SR-14 project.
The CMGC contracting process forges a partnership during the design phase among UDOT, the designer working for UDOT, and a competitively selected construction contractor. By using CMGC, UDOT will minimize risk to the contractor, develop a project schedule, identify potential innovations, and determine cost.
After the design phase, the CMGC process allows UDOT to give the construction contractor involved during design the first opportunity to price the work. An independent cost estimator, along with UDOT’s Engineers Estimate, will be used to evaluate the contractor’s pricing making sure UDOT obtains a fair price.
UDOT maintenance crews are aware of the importance of SR-14 to road users who access cabins and recreation areas. “Meanwhile, maintenance crews are gearing up to take on Mother Nature on S.R. 143,” states a recent Region Four newsletter article. ” The goal is to keep alternative access to the mountain available with the exception of extreme weather events. ” UDOT will coordinate with the National Park Service and National Forest Service. Seasonal closures occur on both SR-14 and 148. Consult UDOT’s CommuterLink Website for up-to-date information about seasonal closures.
- Here is a Link to the UDOT Region Four Newsletter with a more detailed article.
- See a video on KSL.com.