Civil Engineering Reference
In-Depth Information
been advised that the cladding weight is 15 psf. The cladding dead load applied to the
frame being designed is then:
13
2
(30)
Roof Level:
P
w
15
A
T
15
2.93 kips
Story Level:
P
w
15
A
T
15[13(30)]
585 kips
These forces are acting downward due to gravity.
Applicable Load Combinations
To obtain the maximum effects in the frame caused by all of the possible loads, staggered
or patterned loads need to be considered for the gravity live loads. Pattern loads to obtain
the maximum possible forces in a structure were probably discussed when you studied in-
fluence lines in your course on structural analysis. They were also referenced in Chapter
14 of this textbook.
For design of the interior frame under consideration, the load patterns shown in Fig-
ure 21.5 are used. These loads can act singularly or together, as necessary. These pattern
Live load pattern 1 (LL1)
Live load pattern 2 (LL2)
Roof live load pattern 1 (LR1) Roof live load pattern 2 (LR2)
Figure 21.5
Loading patterns for the live loads acting on the frame.
