From: Neil Moore <nmoore(--nospam--at)innercite.com>
Date: Wed, 13 Jun 2001 08:37:22 -0700
We appreciate your effort to provide an elementary sign pole analysis and
to present some methods for developing a spreadsheet. There are a
number of us on the list that design poles for various clients.
Following are some suggestions for inclusion in your spreadsheet.
speed (qs) should be for any velocity. If the local wind speed is
85 mph or 155 mph, the template should be able to calculate
supporting pole itself has to be considered. Shielding by the
sign is not allowed. The Cq for the pole is 1.4 x 2/3rds per note 8
of Table 16-H.
for the various signs is not as clear as it could be on the
spreadsheet. A more organized tabular section would be helpful,
with a check box for flat and circular
factor (not Cs) should actually interpolate a more accurate value.
the possibility of a communication dish(s) also being placed on the sign
structure. (Good rental income for the owner). This could be
part of the tabular input.
tabular section, the weight of each element should be included.
which code is being used. My above comments are considering the
1997 UBC, but there are some differences in the 2000 IBC. Also,
some people may be designing the structure using the AASHTO
Standard Specifications for Structural Supports for Highway Signs,
Luminares and Traffic Signals or for British
easiest is to have a separate page in the spreadsheet for each of these
codes rather that a selection of which code being used on one page.
numerical result should be a total wind force (Vwind) and the height of
the ground (Centroid of effort) to use in the design of the footing or
pier. Note that the moment for the analysis of the footing will be
taken about bottom of the footing or the design moment for the pier will
be taken somewhere below the ground level, depending on whose lateral
pier analysis you use and where the passive soil starts. A separate page
for a spread footing or pier should be considered with the results from
the sign pole(s) analysis linked to these
arithmetic, a more presentable result for the lateral wind force would
not carry the calculation out to two decimal places. This is a pet
peeve of mine; but the lesser numbers make the appearance of a neater
calculation page. In fact, I prefer to do as much of the
presentation of the calculations in kips, inch-kips or foot-kips where it
is appropriate.. Smaller and simpler
Example Problem 10 - Wind Design of Pole-supported Sign and Foundation of
the Wind Commentary to the UBC, obtainable form the Structural Engineers
Association of Washington.
I know of at
least three other consultants on this list who have spreadsheets written
and have been used for a number of years which include all of the
comments above as well as other enhancements. The wind portion for
mine was written around 1989 and the pole section, if I remember
correctly, was written in 1995. Unfortunately for me, these are in
Lotus123 and I am now in the process of converting all of our Lotus
templates to Excel.
Neil Moore, S.E.
neil moore and associates
shingle springs, california