Contractors Devise New Techniques to Battle Extreme Weather, Temperatures
Contractors find that they must use highly customized techniques when building projects in extreme altitudes or environments. While conditions may vary from one project to another, intensive preplanning and out-of-the-box thinking are absolute requirements.
Colorado contractor GE Johnson Construction Co. is planning for challenges in building the Pikes Peak Summit Complex at just over 14,000 ft.
The replacement project for the aging 1960s summit house at the top of Pikes Peak west of Colorado Springs is scheduled to break ground in June 2017 and will be one of the highest-altitude projects of its kind ever constructed in the United States.
The 34,000-sq-ft structure will serve as a new visitor destination building, with exhibit and dining spaces and large viewing areas for the more than 600,000 people who reach the summit each year via the Pikes Peak Highway, the Manitou and Pikes Peak Cog Railway or the Barr or Crags hiking trails.
The extreme weather conditions and high-altitude concerns are forcing GE Johnson to develop project-specific safety measures that will protect workers who will make the journey to the top of the mountain next summer. Crews will meet each morning at a satellite staging area at 10,800 ft., where they will receive the day’s safety planning and job-hazard analysis. They will then be shuttled to the summit at 7:30 a.m. and shuttled back down at 3:00 p.m. each afternoon.
“Our goal is to minimize the amount of labor done at the summit; we want it to be more of an assembly than a construction project,” says GE Johnson senior project manager Jim Hopper, the firm’s technical expert on doing work in challenging locations.
“The production you will get from workers and technicians, whether driving a piece of equipment, going up and down ladders or walking around will be diminished [at 14,000 ft]. We’re looking at how we can prefabricate as much of the project in Colorado Springs as possible.”
Hopper says GE Johnson and its subcontractors have collaborated closely with the design team—GWWO Inc. of Baltimore and RTA Architects of Colorado Springs—to consider and compare materials and systems that can be fabricated in the city. “For instance, we might build parts of the building shell, then disassemble it, take it up on trucks and assemble it in place,” he says.
Material deliveries will be difficult at 14,000 ft as well. The contractor is doing test runs with tractor trailers up the slow, winding Pikes Peak Highway to determine size limitations for vehicles that can navigate the tight corners and make the steep elevation gains. Hopper says they have determined 30 ft to be the maximum length of vehicles transporting materials to the summit.
Ski Mountain Crew
“High-altitude projects create all sorts of challenges that are magnified by the conditions: wind, lightning, altitude sickness, dehydration,” says Alan Rindlisbacher, spokesman for Sandy, Utah-based Layton Construction, a general contracting firm also familiar with building in extreme mountain conditions. “Our foremen are trained to watch for signs of elevation sickness. Some [workers] will acclimate more readily than others, and you end up working with [those individuals who] can take on that type of work.”
Layton’s recently completed Summit at Snowbird Ski & Summer Resort project just east of Salt Lake City also required considerable preplanning to determine how travel conditions would affect the project, which was located at 11,000 ft and accessible only by unpaved mountain roads.
“In essence, we spent the season before we started construction scouting out the road and working with suppliers to ensure they could safely make the trips up and down the mountain,” Rindlisbacher says. “We required a complete buy-in from all involved that it would be a workable task.”
The Summit at Snowbird’s utilitarian structure is designed with concrete, glass and steel elements to withstand hurricane-force winds. Layton’s crews kept a constant eye on weather forecasts and coordinated with Snowbird staff, since incoming storms frequently chased workers off the mountain. Layton also relied heavily on the experienced Snowbird ski resort maintenance crew, whom they hired to drive every piece of construction equipment except for the concrete trucks.
“Snowbird was the logical ‘subcontractor’ to do that work because they had the equipment, expertise and experience to negotiate the mountain roads,” Rindlisbacher says.
The roads were treacherous. Snow and ice had to be cleared regularly to avoid slide-offs. Switchbacks required trucks to back up on sections of the roadway where there was insufficient turning radius to make the tight corners. While a concrete truck’s journey from plant to jobsite is usually an hour round-trip, on this project it took a truck hauling a smaller than normal 7-cu-yd load more than six hours to climb the steep gravel roads, place its load and return to the plant.
The concrete crew also had to account for retardants placed in the concrete to take it up the mountain and accelerants that were added to speed the setting process once there—all the while taking the freezing temperatures into consideration.
Beating the Heat
While high-altitude construction poses its own set of risks, building at the lowest site in North America presents surprisingly similar challenges for material deliveries and worker safety.
GE Johnson is not only constructing one of the highest-elevation projects in the United States but also the lowest. Updates and additions to the 1920s era Furnace Creek Resort in California’s Death Valley will take place in the hottest and driest spot in North America, at 148 ft below sea level, where summer temperatures can reach 125° F.
The GE Johnson/Kitchell joint venture will renovate structures and build new ones designed with desert-friendly materials such as thick, adobe-style walls that hold in cold air at night. OZ Architecture of Denver is designing the buildings, which are small enough to be constructed in phases to minimize the labor required. That’s because, much like working at high altitude, crews can only be active for short periods of time in the extreme desert heat, says Becky Stone, the firm’s managing principal.
Prefabrication of major building systems will take place in neighboring cities such as Las Vegas and Fresno, allowing multitrade assemblies to be performed off site. OZ is selecting materials that can be shipped from relatively close by to avoid long-distance deliveries, and, as a result, delivery frequency may have to increase, Stone says. Crews can only unload a certain number of trucks in a day because the work must be carefully paced, with frequent breaks to avoid heat exhaustion.
The heat is an ever present threat—even an October morning in Death Valley can reach 100° F. A tent will be erected and supplied with misters and drinking water to keep workers hydrated during frequent breaks. Crews will unload trucks during cooler nighttime hours and move the materials around inside an air-conditioned building during the day, Stone says.
Concern for workers’ health and safety also played a role in the BNSF Bradshaw to Aurora Capacity Improvement Project in Aurora, Neb. SEMA Construction’s crews worked on soil stabilization from November through February in temperatures that ranged from 5° F to -25° F. The contractor staged temporary warming huts along the 12.7-mile route, and workers took 30-minute breaks to warm up after each three-hour shift rotation. The huts were kept warm with propane heaters and stocked with food and supplies.
SEMA also devised an innovative approach to warming the frozen ground enough to be able to place materials into the subgrade. An 18-wheel trailer pulled custom-made, propane-fueled ground heaters slowly across the ground to heat the bituminous surfaces to 300° F.
“Our goal was to get as much asphalt down as we could before the winter months. It never got above freezing for weeks; we’d bring the ground heaters in during the middle of the night until the crews came in,” a SEMA project manager says. “We typically work in the winter, but if it’s snowing or too cold, we shut [work] down. That wasn’t an option on this job, and literally no element stopped us.”