Highlights of SGH’s work on this project included the following:
Foundation. The lack of nearby batch plants precluded the use of cast-in-place concrete, and construction of specialty deep foundations was prohibitive due to mobilization constraints and permafrost soil. SGH designed segmental precast concrete foundation elements to create a mat foundation for the radar tower and spread footings with piers for the radar equipment building. To accelerate production, we engaged a Massachusetts precaster who transported the precast elements to Norfolk, Virginia, and we had the precast concrete elements shipped to the site on a supply barge that travels to the site once a year. SGH discretized the foundation elements into repeatable shapes that were small enough to be transported in shipping containers and developed details to simplify fabrication and installation. We utilized post-tensioned bars to clamp the mat foundation elements together and grouted splice sleeves to connect the piers to the footings.
Structure. The original project specifications for the equipment support building called for structural steel shapes and bolts based on ASTM standards. To accelerate the schedule for the Danish contractor, SGH researched equivalent European materials and structural shapes, researched bolts from the British Standard, and developed details to accommodate these European products.
Building Envelope/Fire Protection. SGH designed the building enclosure for wind pressures up to 225 psf. When the Danish contractor wished to use building cladding (insulated metal wall panels) from a European manufacturer to accelerate the schedule, SGH coordinated independent testing to verify compliance with ASTM requirements for fire rating.