Design/Build AEF FOL Aircraft Maintenance Hangar – AAFB, Guam
The project entails the construction of an arch shaped 4,700sm concrete aircraft maintenance hangar, related support facilities, concrete aircraft aprons, tow ways, and asphalt service road on a 50,000sm site at Andersen AFB, Guam. The hangar and related site improvements will provide a reliable shelter and an air-conditioned environment for B-2 and B-52 aircraft maintenance and support for “hard broke” B-1B, B-2, B-52, KC-135, F-22 aircrafts that can not be flown off island prior to a typhoon.
The main hangar structure will be 20m high at its peak and have a gross floor area of 3,600sm. The hangar will have a cast-in-place concrete foundation with post-tensioned grade beams and precast concrete wall and roof superstructure comprised of folded plate arch rib segments. Adjacent single story and two story support structures housing open mechanical equipment yards, enclosed storage and equipment rooms, second floor mezzanine offices, and related facilities will be constructed of conventional cast-in-place and precast elements and will have a total gross area of 1,100sm. In all, approximately 800 metric tons of reinforcing steel and 9,500 cubic meters of concrete will be used to construct the hangar, building extensions, site civil works, concrete aprons and tow ways.
A 10.7m high by 63m wide bi-parting hangar door and pivoting tail door will be provided at each end of the hangar. A similarly sized vertical lift fabric door will be installed at the center of the hangar to allow direct pull through a B-52 aircraft when the middle fabric door and outer hangar doors are in the open position. In the closed position, the center fabric door will divide the hangar into two separate bays large enough to accommodate one B-2 bomber in each air conditioned bay.
The hangar, offices and several ground floor rooms will have central air-conditioning and ventilation systems. Eight 65 ton ACCU’s (four per bay) shall provide independent cooling capability for each bay of the hangar. The hangar bays will have pre-conditioned ventilation units for fuel cell maintenance, spot ventilation systems, compressed service air and breathing air systems for aircraft maintenance. Additional mechanical/electrical systems to be constructed for the project include high expansion foam and wet pipe fire extinguishing systems, 200,000L steel fire water tank, 300mm fire water main, trench drains, dual walled effluent collection piping and 400,000L process storage tank, provisions for 400hz power, security, fire alarm, and PBX systems, 650KW stand-by generator, two separate underground power services with 15kv 4-way switch and two sets of 2000KVA, 13.8KV/480V pad mounted transformers and 480V main panels.
Special project considerations include fast track 18 month design-build schedule, base security and access constraints, active airfield construction coordination and safety procedures, and Class 1 Division 1 and Division 2 explosion proof electrical systems required within the hangar.
