H.1 Vehicle maintenance facility
a. Introduction: This example problem demonstrates the design of a vehicle maintenance facility. The
structure is considered to be a Standard Occupancy Structure. This type of building is to be designed to meet
Performance Objective 1A (protect Life Safety). Most of the structures designed for military use fall into this
category. For this example it is assumed that the site has spectral accelerations of 0.75% g at 0.2 seconds and 0.40%
g at 1.0 seconds per the MCE maps. The soil classification is type D.
(1) Purpose. The purpose of the is example is to demonstrate the design of a structure to meet
Performance Objective 1A following the steps outlined in Table 4.5.
(2) Scope. The scope of this example problem includes; the design of all major structural elements such as
the steel gravity framing, CMU shear walls and the steel braced frames, as well as the connections between the
various structural elements. The design of the foundations, nonstructural elements and their connections and
detailed design of some structural elements such as the concrete floor slab and pilasters are not included.
(1) Function. This building is to be used as a vehicle maintenance facility. The building is not considered
to be mission critical and is therefore is designed to meet the Life Safety Performance Level.
(2) Seismic Use Group. The occupancy or function of the structure does not match any of the conditions
required for Special, Hazardous, or Essential Facilities set forth in Table 4-1. Therefore, the building is categorized
as Seismic Use Group I.
(3) Configuration. The building is a rectangular, six bay, one-story structure. At each end of the building
is an office and bathroom space. Above the office space at both ends is a mezzanine accessed by a staircase and is
used for storage. The building measures 160'-0'' (48.80m) long by 40'-0'' (12.20m) wide in plan. The top of the roof
is 20'-0'' (6.10m) above the grade on average with the roof sloping in the transverse direction (N-S) to allow for
(4) Structural Systems.
Steel framing is selected to support gravity loads. The frames provide for the large open floor areas needed for the
motor pool. The steel beams around the perimeter of the building are used to span the large roll-up door openings,
carrying the gravity loads from the roof as well as the weight of the metal roll-up doors.
The roof consists of untopped 1-1/2 inch (38.1mm) metal deck that spans 6'-8'' (2.03m) to open web steel joists.
The joists are selected due to their ability to span 40'-0'' (12.2m) transversely to steel beams which are supported by
steel columns spaced at 20'-0'' (6.10m) on center. The columns are supported by spread footings and the walls are
supported by strip footings (the design of the footings is omitted for this example).
The mezzanines at the end bays of the building must support the large storage live loads (assumed 125 psf or
5.99KN/m2). This calls for the use of some type of concrete slab to support the high loads. A concrete filled metal
deck is selected from a manufacture' catalog consisting of normal weight concrete fill on 1-1/2'' (38mm) metal
deck. The deck spans in the transverse direction over steel beams at 8' 0" (2.44m) on center. The beams bear on
pilasters projecting from the CMU walls (design of pilasters not in scope of problem).
The primary lateral system in the transverse direction consists of reinforced CMU walls. The building has a
complete frame system so the walls are considered nonbearing. There is no need for large openings in the transverse
walls, which allows for the use of shear walls. The metal decking at the roof level acts as a flexible diaphragm that
transfers shear to the exterior CMU shear walls and the interior CMU shear wall based on tributary areas. The metal