15 September 1999
EXAMPLE PROBLEM C2
REINFORCED BRICK MASONRY BUILDING
C2-1. Building Description
The Enlisted Men's Barracks at Brigade Headquarters (Building 3733) (Fort Lewis, Washington)
is a three-story reinforced brick masonry unit (BMU) structure. According to the as-built
drawings, it was designed in 1976.
The building has overall plan dimensions of 80 feet by 48 feet, and consists of three sections.
One section on the east end of the building has plan dimensions of 54 feet by 44 feet. The west
section has plan dimensions of 16 feet by 42 feet, and is offset 6 feet to the south of the east
section. The two are connected by a 10-foot by 31-foot section of corridors and stairs. See
Figure C2-1 for floor plans, and Figure C2-2 for elevations.
a. Vertical-Load-Resisting System. The ground floor is a reinforced concrete slab-on-
grade. For the second and third floors of the east section, the floor slabs consist of 2-inch
lightweight concrete and 3-inch, 20-gauge composite deck over wide-flange steel beams. For
the west and the connecting sections, the floor slabs consist of 8-inch-thick reinforced concrete.
The roof consists of built-up roofing and rigid insulation over 20-gauge by 1-inch steel decking
supported by truss joists and steel girders. Vertical loads are supported by steel columns in the
interior, and reinforced BMU along the exterior. The footings consist of individual spread
footings for the columns, and strip footings along the perimeter of the structures.
b. Lateral-Load-Resisting System. The primary lateral-force-resisting system consists
of the roof and floors acting as diaphragms and transmitting lateral forces to the perimeter BMU
shear walls. The roof load is transmitted by the steel decking to the walls through steel angles
connected to the walls with 5/8-inch-diameter bolts. The BMU walls are reinforced vertically
with #4 bars at 24 inches on center. Horizontal bond beams with four #4 bars are provided at
each floor level, with intermediate bond beams with two #4 bars at 3-foot, 4-inch centers, and
over door and window openings. The lateral force from the floor diaphragm is transmitted to the
ground through these BMU shear walls. There are several CMU (concrete masonry unit) walls
on the first floor, which also contribute to resisting the lateral loads.
C2-2. Building Review Report
a. Seismic Review of Structural Systems. This form procedure described in Chapter 2
is performed using the Lateral Load System Data Sheet and Structural Review Score Sheet.
b. Lateral Load System Data Sheet. This form (Figure C2-3) is completed in
accordance with the guidelines in Appendix B. The information is taken from the building
drawings and by visual inspection of the building. The building is categorized as FEMA 310
Model Building Type 13, based on the description of structural systems given in FEMA 310,