Filter
Top Products
Section 5
5-221
5.31.2.10 Canadian Seismic Code (NRC) - 1995
Purpose
This set of commands may be used to define the parameters for
generation of equivalent static lateral loads for seismic analysis
per National Building Code(NRC/CNRC) of Canada- 1995 edition.
Depending on this definition, equivalent lateral loads will be
generated in horizontal direction(s).
Description
The seismic load generator can be used to generate lateral loads in
the X & Z directions for Y up or X & Y for Z up. Y up or Z up is
the vertical axis and the direction of gravity loads (See the SET Z
UP command). All vertical coordinates of the floors above the
base must be positive and the vertical axis must be perpendicular
to the floors.
The minimum lateral seismic force or base shear (V) is
automatically calculated by STAAD using the appropriate
equation(s).
V =
R
V
e
×
6.0
(per sentence 4, section 4.1.9.1)
See Sections 1.17.2,
5.32.12 and
E
xample Problem
E
xamp14_NRC.std
Where V
e
, the equivalent lateral seismic force representing elastic
response is given by
V
e
=
WFISv
×
×
×
×
(per sentence 5,section 4.1.9.1)
Where,
v = Zonal velocity ratio per appendix C
S = Seismic Response Factor per table 4.9.1.A
I = Seismic importance factor per sentence 10 section 4.1.9.1
F = Foundation factor conforming to Table 4.9.1.C and sentence 11 section
4.1.9.1
W = Total load lumped as weight per sentence 2 section 4.1.9.1