Need a book? Engineering books recommendations...

Return to index: [Subject] [Thread] [Date] [Author]

Earthquake Forces

[Subject Prev][Subject Next][Thread Prev][Thread Next]
Reply to Kipp Martin:

1997 UBC Section 1630.1 is meant to define "E" as it is listed in the
fundamental load combinations in section 1612.  Thus all earthquake
forces "E" get influenced by rho.  BUT....Lateral forces on elements and
components (UBC 1632) sets rho=1.0 instead of whatever the building's
structural system rho is.  Since your masonry wall is an element, yes
you use rho, but it is 1.0 in value.

Another clarification,  diaphragms are no longer listed under the table
of "elements of structures" (UBC Table 16-O), but have there own
independent section 1633.2.9.  Unfortunately, rho is not clearly defined
for the design of diaphragms.  From my discussions with several of those
associated with "officially" interpreting the 1997 UBC, rho is supposed
to be 1.0 for diaphragm elements of the structure.  Don't quote me but
pray it's true.

Chasing down the correct interpretation of portions of the 1997 UBC has
been tricky for me and a wild ride to say the least.  Stay tuned and
hold on!

John Lawson SE
Kramer & Lawson, Inc.