Lightweight EPS Geofoam Solves High Altitude Construction Challenges
Located just 25 miles east of downtown Salt Lake City, Utah, Snowbird Ski & Summer Resort is a dream realized for visionary founder Richard “Dick” Bass. A lifelong love of mountains and an adventurous spirit led Bass to become the first person in the world to climb to the highest point on each of the seven continents, a feat he completed in 1985 at the age of 55. Bass’ ability to pushing limits beyond known boundaries also propelled the realization of his grandest ambitions for his mountain resort.
For more than 20 years, Bass envisioned a glass-enclosed lookout perched at the summit of Snowbird’s highest point, Hidden Peak, 11,000 feet above sea level. Bass worked with designers to consider plans for a 23,000 square foot capsule that allowed visitors to peer over the Wasatch Range and Mineral Basin and get the on top of the world feeling that only the summit of a mountain can provide. Accessible by only an aerial tram that was built in 1971, Hidden Peak offers limitless views of spectacular surroundings in every direction. Building on the summit, however, presented a wide range of situational challenges to designers at GSBS Architecture and Layton Construction. Of the many, one of the most significant challenges the design and construction team had to resolve involved stabilizing the tram’s mountain top receiving station to ensure that the new building did not dislodge the existing structure.
Atlas Molded Products’ lightweight, durable, and incredibly strong molded polystyrene geofoam comes into play as a versatile, reliable solution to a wide range of subgrade stabilization situations. High atop Hidden Peak, Atlas Geofoam gave designers, builders, and owners the confident conviction required to realize a dream built right on the edge of impossibility.
The Challenge
From logistics, equipment, and materials to health and human performance, the challenges of building anything at 11,000 feet above sea level are immense. In the case of the glass-enclosed guest services center, dining hall, and observation deck aptly named The Summit at Snowbird Ski and Summer Resort, design planning had been in progress for nearly 20 years before the very first steps of construction were ever taken. Environmental conditions included heavy winds of up to 135 miles an hour, temperatures that reached well-below zero, and extreme altitude and accessibility impediments for manpower, materials, and equipment. In a construction program phased over two summer off-seasons, builders at Layton Construction worked hard to deliver men, materials, and equipment to the summit using a combination of the aerial tram and Snowbird’s unpaved mountain road, which was difficult and extremely time-consuming to safely navigate in either direction. During the first season of construction, Layton cleared the site and put in most of the new structure’s concrete footings, foundation, steel structure, floor decking, and concrete work. In the second season, the building was enclosed with roofing and glazing while mechanical, electrical, plumbing, drywall, and interior finishes were completed.
During the first summer of construction, site excavation for the new foundation stretched across the site to the tram structure, exposing the foundation wall of the mountain-top attachment site. Built some 43 years previously using CMU blocks, designers, builders, and owners understood that uncovering the tram attachment building’s foundation represented a serious project vulnerability. Once uncovered, backfilling with soil would potentially expose the foundation walls to lateral pressures as the disturbed soil resettled. This pressure could cause a dangerous shift in the foundation’s stability; a condition that had to be eliminated.
The Solution
Atlas Geofoam is a gamechanger when it comes to subgrade structural stabilization and the confidence placed in the material’s absolute consistency is well established by use cases like Hidden Peak. Molded polystyrene is a closed-cell plastic that is molded into standard-size blocks as large as 40 inch x 48 inch x 96 inch and custom-sized blocks as large as 40 inch x 72 inch x 288 inch. Well-known for its incredibly high compressive resistance, and long-term stability, at Snowbird, designers used Atlas Geofoam to provide a structural solution between the tram receiving station’s foundation wall and the foundation of the new building.
While architects at firms like Salt Lake City’s GSBS Architecture appreciate geofoam’s predictable performance in conditions that border on extreme, builders like Layton find it to be particularly well suited to circumstances where a lightweight fill is needed due to constricted access or structural loading. In support of the construction services program, Atlas Molded Products developed shop drawings for the configuration of the geofoam within the void between the new construction and existing to minimize waste. Atlas also developed a just-in-time delivery schedule to ensure that the entire geofoam purchase order could be delivered in a single trip up the mountain.
At 11,000 feet above sea-level, it is easy to understand how builders would appreciate geofoam’s lightweight portability. Without specialized equipment or knowledge, the large rectangular blocks used to fill the void between structures were moved into place by hand by a few laborers. A hand-held hot wire cutter was used to customize select blocks as needed to fit around protrusions in the forms. Once in place, the geofoam was covered with free-draining gravel and a concrete patio slab.
Special conditions require special solutions and, often special products. Atlas Molded Products strives to treat each opportunity as special and works with designers, builders, and owners to establish rock-solid confidence in our building materials and facilitate efficient construction. Atlas Geofoam is a durable, weather- and climate-proof structural solution well suited to both below- and above-grade challenges wherever civil engineering faces limitations. Lightweight, customizable, and degradation resistance geofoam from Atlas Molded Products help the design and construction industry surmount any challenge, even at 11,000 feet.
