Developer/Owner

NAVFAC Pacific

Architect

BRPH

Contractor

dck pacific guam, LLC

Location

Andersen Air Force Base, Guam

Background

This new approximately 72,500 SF design-build aviation maintenance hangar features high bay spaces, crew and equipment spaces, administrative spaces, and a 2,000 SF fire pump building.  The hangar will support MV-22 aircraft and, with a minimum of renovation, be capable of supporting other aircraft, such as the KC-130J, CH-53, UH-1, and AH-1, in the future.  This project includes Antiterrorism Force Protection (AT/FP) features and complies with AT/FP regulations and physical security mitigation in accordance with DoD Minimum Antiterrorism Standards for Buildings. The hangar consists of a structural steel/concrete roof supported on cast-in-place concrete walls and shallow spread footings.  The administration area is precast concrete double tees supported on cast-in-place concrete walls and shallow spread footings.   

The Science and Design of Structural Engineering

The primary challenge was providing an economical long span roof structure that could resist extreme seismic forces and 195 mph typhoon winds and be efficiently constructed in the remote island of Guam.  Built up structural steel roof trusses supporting wide flange purlins with metal deck and concrete topping were used to frame the roof.  The trusses span from the back wall of the hangar to a 28.5 ft.-deep steel box truss clear spanning 327 ft. over the hangar door opening.  Design of the roof structure was further complicated by the fact that the approaches to addressing extremely high wind loads is often at odds with those for handling high seismic demands.  For example, adding concrete topping helps resist high uplift forces, but it also increases the seismic inertial forces the building must resist.  Such considerations were carefully assessed and fine-tuned throughout the design process.  

Client Benefits

BASE worked intimately with the contractor and steel fabricator to design the long-span steel roof system.  3D models were shared between BASE and the steel fabricator starting in the design phase to ensure that the final product not only met all building code requirements, but could also be efficiently fabricated, shipped and erected.  This close coordination and teamwork allowed the structural steel package to be procured and mill orders placed prior to the final overall design being completed.