Civil Engineering Reference
In-Depth Information
column lines 1 through 4 carry the floor and roof loads transferred to them from the deck
beams. The girders along column lines
A
through
D
carry only their self-weight, and the
force distributed to them as load is distributed through the structural system. All floor and
ceiling loads are carried by the deck beams and are transferred to the girders on which the
deck beams rest.
Interior Girders along Column Lines 2 and 3
Floor Dead Load:
w
D
(19
120)30
4.17 kips/ft
Floor Live Load:
w
L
(80)30
2.40 kips/ft
Roof Dead Load:
w
D
(17
120)30
4.11 kips/ft
Roof Live Load:
w
L
(20)30
0.60 kips/ft
Exterior Girders along Column Lines 1, 3, and 4
Floor Dead Load:
w
D
(19
120)15
2.09 kips/ft
Floor Live Load:
w
L
(80)15
1.20 kips/ft
Roof Dead Load:
w
D
(17
120)15
2.06 kips/ft
Roof Live Load:
w
L
(20)15
0.30 kips/ft
Lateral Loads Acting on the Frame
For our purposes in this discussion, we will assume that the cladding is attached to the
building in such a manner that the loads from the cladding are applied to the structural
frame at the intersections of the primary members. We will assume that we have been ad-
vised that the lateral loads applied to the cladding are a net 30 psf—a 15 psf pressure load
applied to one face and 15 psf suction applied to the opposite face.
For this discussion, we will be designing a typical frame along column line 2 so that
we only need to calculate the lateral forces acting on that frame. If we were designing the
entire frame, we would have to calculate the lateral loads acting on all of the frames. On
the frame under consideration, the lateral loads are:
13
2
(30)
Roof Level:
P
w
15
A
T
15
2.93 kips
Story Level:
P
w
15
A
T
15[13(30)]
5.85 kips
These forces act on both faces of the frame. When a pressure load acts on one side (posi-
tive sign), suction load acts on the opposite side of the building (negative sign).
Cladding Dead Load Acting on the Frame
The manner in which the cladding is attached to the structural frame depends on its type
and manufacture. For the purposes of this discussion, it is assumed that the cladding is at-
tached in such a manner that the loads from the cladding are applied to the structural
frame at the intersections of the primary members. This was the assumption made as to
the transfer of lateral loads to the building frame. We will assume further that we have
