TM 5-810-15
siderations. Generally, the main building will con-
loads for steam plant floors are as follows:
sist of: a steam generator bay (or firing aisle the
semi-outdoor units); an auxiliary bay for feedwater
Basement and operating floors
200 psf
heaters, pumps, and switchgear; and general spaces
Mezzanine, deaerator, and miscellaneous
as may be required for machine shop, locker room,
operating floors
200 psf
laboratory and office facilities. For very mild
Office, laboratories, instrument shops,
climates the steam generators may be outdoor type
and other lightly loaded areas
100 psf
(in a weather protected, walk-in enclosure)
although this arrangement presents special
Live loads for actual design will be carefully
maintenance problems. If incorporated, the elevator
reviewed for any special conditions and actual
will have access to the highest operating level of
loads applicable.
the steam generator (drum levels).
(2) Live loads for equipment floors will be
based on the assumption that the floor will be
b. Layout considerations. The layout of the
utilized as laydown for equipment parts during
structural system will identify specific requirements
maintenance. Load will be based on heaviest piece
relative to vertical and horizontal access, personnel
removed during maintenance.
needs and convenience, equipment and respective
(3) Live load assumptions will be in accord-
maintenance areas, floors and platforms.
ance with TM 5-809-1.
c. Soil investigation requirements. A subsurface
g. Other loads. In addition to the live and dead
exploration program will be conducted. Design
loads, the following loadings will be provided for:
information regarding the interaction of the struc-
(1) Piping load. Weight of major piping
ture and the surrounding ground is required. In
sized and routed will include weight of pipe,
addition, an investigation should furnish informa-
insulation, hydraulic weight (pipe full of water) in
tion as to the source of construction materials and
addition to any shock loads. Pipe hanger loads will
the types and extent of materials which will be
be doubled for design of supporting steel. In
encountered during construction will be investi-
congested piping areas increase live load on the
gated. Information required for design includes:
supporting floor by 100 pounds per square foot
extent of each identifiable soil stratum, depth to top
(psf). Structural steel will be provided to
of rock and character of the rock, elevation of
adequately support all mechanical piping and
normal ground water at site, and engineering
electrical conduit. Provision will be made to
properties of the soil and rock.
accommodate expansion and contraction and
d. Foundation design. Selection of the type of
drainage requirements of the pipe. Piping
foundation to be used for each component of the
connections must be made to preclude rupture
plant (i.e., main building, boiler, stacks and coal
under the most adverse conditions expected. Pipe
handling structure) will be determined from the
supports will be close coupled to supporting struc-
subsurface exploration data, cost considerations
tures when the more severe seismic conditions are
and availability of construction trades.
expected.
e. Structural design. Thermal stations will be
(2) Wind loading. Building will be designed
designed utilizing conventional structural steel for
to resist the horizontal wind pressure available for
the main steam station building. Separate structural
the site on all surfaces exposed to the wind. Wind
steel will be provided to support building floors and
load assumptions will be in accordance with TM 5-
platforms; boiler steel will not be used in support
809-1.
building structure. The pedestal for supporting the
(3) Seismic loading. Buildings and other
turbine driven boiler feed pump if utilized will be of
structures will be designed to resist seismic loading
reinforced concrete. Reinforced concrete or
in accordance with the zone in which the building
masonry construction may be used for the building
is located. Seismic design will be in accordance
framing (not for boiler framing); special concrete
with
inserts or other provisions must be made in such
TM 5-809-10.
event for support of piping, trays and conduits. An
(4) Equipment loading. Equipment loads are
economic evaluation will be made of these
furnished by the various manufacturers of each
alternatives.
equipment item. In addition to equipment dead
loads, impact loads, short circuit forces for genera-
f. Structure loading.
tors, and other pertinent special loads prescribed by
(1) Buildings, structures and all portions
the equipment function or requirements will be
thereof will be designed and constructed to support
included. Dead load assumptions will be in accord-
all live and dead loads without exceeding the
ance with TM 5-809-1. Ductwork, flue gas breech-
allowable stresses of the selected materials in the
ing, stacks, and other hot equipment must be
structural members and connections. Typical live
2-3
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