I think the basic code provisions for setbacks and towers on a base were
derived from a report by the "SETBACK SUBCOMMITTEE" chaired by John A. Blume
with M.T. Knox and Ed Lindskog as members issued May 13, 1958. They
describe the question at hand in a simple way: "Does the dog wag the tail or
the tail wag the dog?" This short report (about 7 pages) provided
recommended code provisions. For those of you with access to old versions
of the bluebook, it is included in the 1988, 1980 and 1973 versions of the
bluebook as an appendix [Appendix 1D5b in 1988(which refers to the "1959
Recommendations, Appendix C); Appendix C in 1980, or Appendix C in 1973].
It appears to be largely based on work done by Blume in the 1935.
Bill Cain, S.E.
From: Christopher Wright [SMTP:chrisw(--nospam--at)skypoint.com]
Sent: Friday, January 14, 2000 9:11 AM
To: SEAOC Newsletter
Subject: Re: Dynamic Analysis Question
>It is my interpretation that the intent of the code is to allow a
>simplified (analytically) analysis for qualified structures and
>full structure model for a dynamic analysis.
This is probably analogous to the Nuclear codes which allow
(like cranes) to be analyzed separately from the plant structure as
whole, provided the subsystem contributes less than 10% of the
Christopher Wright P.E. |"They couldn't hit an elephant from
chrisw(--nospam--at)skypoint.com | this distance" (last words of Gen.
___________________________| John Sedgwick, Spotsylvania 1864)