The 60,000 sf Armed Forces Reserved Center, 20,000 sf Operational Maintenance Support and Unheated Storage facility is unlike other more typical Army Reserve facilities, in that all component areas combine into one large building with two wings.
The structure consists of steel joists supported by steel beams and masonry bearing walls around the perimeters, with interior shear walls for lateral load resistance. The building has a 4:12 sloping roof with standing seam metal roofing over a structural steel roof deck. In the center of the building, over the kitchen, is a small flat area of the roof that houses the mechanical roof top units. The building has several very long, 50-60 foot exposed hollow structural trusses. The entry truss has the same 4:12 roof slope, and is galvanized and finished for additional corrosion resistance. Another truss is in the interior of the building that forms one side of the assembly hall, which is approximately six feet higher than the rest of the roof.
The raised area of the assembly hall has many windows in order to let in natural light. Normally this would not be a design challenge; however, as with other Department of Defense projects, all glazed openings, windows, skylights and doors have to be designed for certain blast pressures. This blast pressure has to be applied to the glazing itself. The entire wall that was formed by this truss had large amounts of pressure applied to it. These large members then became part of the truss, becoming an overall system for gravity and lateral load resistance. It successfully met the aesthetic functions as well as resisted the vertical pressures from the roof and horizontal pressures from the blast loading as prescribed by the Department of Defense.
Seismic design was a crucial part of the project as the site is located in the center of the country near the New Madrid Fault. In the layout of the facility a number of seismic expansion joints were incorporated, invisible from the outside. These were strategically located where the wings of the buildings came together in order to allow them to move independently. Were this not designed and constructed correctly, the building could fail during large seismic events.
In the maintenance area of the facility, the roof was higher than average and the walls were perforated with large 16 x 15 foot doors. The walls were cast-in-place concrete to increase strength and durability and carry the lateral load. These walls also served as hybrid shear wall/concrete moment frames. Also in this area of the facility is an overhead bridge crane, used to service military vehicles. It is supported off the walls at the ends and off the center columns in the middle of the bays.
Blast pressures were also important project considerations. Therefore, the masonry walls around the doors and openings were heavily reinforced to take the blast pressure and redistribute it to the roof diaphragm and floor. The facility also has an exterior covered wash bay, which is attached to the end of the maintenance bay wing. The bay is exposed galvanized structural steel with finish paint for enhanced corrosion protection.
