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80 / BUILDING DIALOGUE / September 2019 frost layer, created a zone of warmth that melted portions of the permafrost. Despite a fix at the time, problems persisted for the life of the building. To reduce the likelihood of the new structure shifting, the struc- ture will bear on the bedrock and the foundation will be placed as much as 35 feet below the permafrost at the north side, where the building slopes up to match the summit slope. Directly below the foundation floors, the permafrost layer is to be removed and replaced with 3-inch crushed bedrock fill. • Building materials. Building materials are also a significant issue at this altitude and in the permafrost. To account for all possible issues, we employed thermodynamicist Bob Pintner from Alas- ka-based R&M Consultants. Together, CTL’s materials experts and the Alaskan heat engineers devised building materials that could withstand both the cold and altitude and be built in a facility in Colorado Springs, yet maintain integrity at the high altitude. It’s not just equipment that has a much lower productivity out- put on the peak. Workers are required to pass extensive physical examinations to ensure they can handle the lower oxygen content, and shifts are kept short to prevent negative health effects. To help accommodate, we designed a building shell that can be preman- ufactured at a lower altitude in prefabrication shops in Colorado Springs. There are costs, though. To transport the shell to the construction site, the size of each transport load has to be very carefully calcu- lated, as materials need to be delivered and/or hoisted up the steep, winding, limited-weight-bearing-capacity road. It can take hours to haul heavy loads just a few miles. Recently we had to drive a steel track hoe up and down the mountain – at speeds barely reaching 3 mph. It took six hours to get down the mountain, in the middle of the night to avoid any car traffic. Construction first began in June 2018 and resumed again this May. The next phase of the project involves pouring the foundations for the visitor center and the adjoining U.S. Army Corps of Engineers High Altitude Research Laboratory. The team hopes to install the lower portions of the foundation walls this season, along with part of the main structure for the complex. The team will also conduct site improvements in phases, since the existing Summit House will remain in operation until the new complex is completed. We are hopeful that Mother Nature cooperates, confident in our planning, but only sure of one thing: We won’t get any easy an- swers. \\ / No Easy Answers / OPENING ART: CTL|Thompson engineers conduct footing observations and testing at the summit. LEFT: CTL|Thompson engineers test soil conditions at the future site of the new Pikes Peak Summit Complex. RIGHT: Work crews unload premanufactured foundation walls hauled to the summit from prefabrication shops in Colorado Springs. BOTTOM: CTL|Thompson engineers install micropiles, a deep foundational element cased in PVC through the icy ground to break the bond between the pile and the ice, to support the summit's new central walkway.