The SR-14 rebuilding project is progressing well despite slope movement that has required additional work.
This aerial photo was taken shortly after the landslide occurred.
Last October a massive landslide destroyed a half-mile section of SR-14. UDOT’s construction contractor, Kiewit Western Co., successfully opened the road by Memorial Day, ahead of schedule. But slope instability in the west end of the project area required UDOT and Kiewit to expand the scope and duration of the work.
The culprit: weak soils
“We’ve basically got weak layers that are hidden and very difficult to isolate,” says UDOT Senior Geologist David Fadling. An investigation of the slide area was completed during the design phase of the project. Hundreds of feet of six inch diameter borings were drilled, but the weak layers were still difficult to detect. “Unfortunately we were not able to find out where this weak layer was until we started to excavate for it.”
The steep terrain is causing other difficulty. Workers are excavating over 300 thousand cubic yards of dirt from the top of the slide area and placing it at the toe in order to stabilize the slope. “The terrain is extremely difficult to access,” says Fadling.
UDOT project team members are pleased with Kiewit’s work. “The thing that stands out for me is their willingness to perform very difficult work,” says Fadling. “When asked to excavate back to the cliffs to remove more of the slide at milepost 7.5, they accepted the challenge.”
UDOT Resident Engineer Leif Condie is on the construction site often as work is occurring and likes Kiewit’s attention to safety. The company is very proactive at protecting workers and the traveling public. Kiewit workers continuously review “why and how to prevent incidents,” says Condie. “I’ve never seen anything like it.”
Collaboration between UDOT and Kiewit has allowed work to move forward quickly and efficiently. UDOT initiated a Construction Manager/General Contractor contract for the project. The innovative method allows the contractor to give input during the design phase. “It becomes a very efficient design by the time it reaches construction,” according to Michelle Page, UDOT Project Controls and Innovative Contracts Manager.
Besides efficient progression, collaboration has resulted in cost savings. For example, the initial cost estimate for Phase Three of the project which included repairing some minor slide areas was $3 million. “They did it for $1.7 million,” says Reuel Alder, CMGC Engineer. “It’s that interaction from looking at the problem from multiple perspectives” during design.
UDOT Project Manager Daryl Friant believes that collaboration with the contractor has “really helped us get a handle on constructability and cost.” Kiewit has submitted fewer change orders as compared to typical projects. Excessive change orders can push projects over the budgetary limit. “It really has been a true partnering effort.”
Safety dictates the maintenance of traffic
Workers are excavating earth from the slide area on very steep terrain. Because of the potential danger of rocks rolling down the slope, traffic is only allowed through at night from 7 p.m. to 7 a.m. while work proceeds during the day.
“It comes down to safety and efficiency,” says Kevin Kitchen, Public Involvement Manager at UDOT Region Four.
“Amidst changing conditions, we’ve provided a consistent travel window for critical economic functions in the area while at the same time creating safe public passage and a safer work environment. The daytime closures significantly improve work flow, reduce project duration, and save taxpayers money, making it less likely that other infrastructure projects will be jeopardized or postponed.”
The road will be open from Tuesday, July 3 at 4 p.m. through Monday, July 9 at 7 a.m. “twenty four hours a day to facilitate the traffic on the national holiday – probably the busiest weekend we have,” reports Condie. “We’re trying to meet the public needs not just the contractor’s.”