The equations in section 1630.1.1 are for the design of individual elements
only. Once you obtain Eh from your analysis then <<...>> factor and Ev are
applied to design the elements. Equation 30-2 should only be used when it is
specifically referred to such as in case of collectors as required in
1633.2.6. This load combination is used when you design critical elements of
the structure that you want to ensure their adequacy in case the actual
seismic forces exceed the assumed design values.
Hope this helps
From: rlewis(--nospam--at)techteam.org [SMTP:rlewis(--nospam--at)techteam.org]
Sent: Monday, June 07, 1999 3:18 PM
Subject: 1997 UBC 1630.1.1
I am using 1997 UBC for the first time. I am a little confused with
My understanding from reading the code, the E and Em factors here
are to be
used in the load combination equations of Section 1612. I guess the
question is, what are these values? Are these values I use to
individual members, or values I use to do my frame analysis with?
Do I take
my base shear calculated in equation 30-4 and multiply it by these
use in my frame analysis?
It appears to me that equation 30-1 combines a ratio of the
vertical load to a maximum seismic load. For a frame analysis, is
maximum horizontal load? Equation 30-2 combines a seismic
factor with a horizontal load. Is this also a maximum horizontal
Thanks for your help in understanding this.
Richard Lewis, P.E.
Missionary TECH Team
The service mission like-minded Christian organizations
may turn to for technical assistance and know-how.