Updated March
15, 2010
AN Wireless
Tower Company, LLC has modified our Allowable Design Loading tables and
Foundation Plans to adhere to Approved National Standard ANSI/TIA-222-G.
This Standard, sometimes referred to simply as 'Revision G' has replaced
ANSI/TIA/EIA-222-F.
Revision G
requires more site-specific parameters be given consideration prior to
both specification and construction of tower and foundation, as compared
to Revision F. Some of these parameters which now require attention
include Exposure Category, Structure Classification and Topographic Category.
The minimum design windspeed has gone from 70-mph fastest-mile under Revision F,
to 90-mph 3-second gust under Revision G. With new wind force equations in Revision G,
the change in wind speeds alone does not produce a significant change to the
wind forces on towers. The introduction of the parameters listed above
is proving to have a more substantial impact. In addition, the Soil Type now carries
a more finite definition as compared to the 'Normal Soil' specification which was phased
out with Revision F.
It is ultimately
up to the purchaser to properly specify a tower for a given site. Care
must be taken in order to fully understand the information contained in
our Allowable Design Loading tables, which are displayed as PDF files accessed
through the links below.
The 'Sheet
Title' block found in the lower right hand corner of each Allowable Design
Loading table includes Category, Classification and Soil Type description
information for that table.
The 'Notes'
section found in the center of each Allowable Design Loading table provides
thorough explanations on each Category and Classification for that table.
Details regarding
'TIA 222-G - Annex F - Presumptive Soil Parameters' are found in the PDF
link below under this title.
With Revision
G, and because of an increased number of foundation sizes, our foundation
plan lettering system (A, B, C, D, E) has been reversed in order alphabetically
from our previous lettering system. Now, 'Type A' is our smallest available
foundation size, and 'Type G' is our current largest foundation size. Our
new Revision G Allowable Design Loading tables provided below will correctly
match up with this new foundation type lettering system.
Our previous
Allowable Design Loading table created under ANSI/TIA/EIA-222-F-1996 -
as well as foundation drawings found previously on this website or elsewhere
shall no longer be used.
In all cases
the services of a Geotechnical Engineer (Geotech) are recommended in order
to properly identify the soil type on site prior to tower specification
and foundation excavation. We can provide custom foundation plans based
on weak soils for a fee, based on a customer supplied Geotechnical Report.
HD / LD
Towers - Allowable Design Loading Tables
HD-LD
Allowable Design Loading - Exposure Category B - Soil Type Clay
HD-LD
Allowable Design Loading - Exposure Category B - Soil Type Sand
HD-LD
Allowable Design Loading - Exposure Category C - Soil Type Clay
HD-LD
Allowable Design Loading - Exposure Category C - Soil Type Sand
HHD Towers
- Allowable Design Loading Tables
HHD
Allowable Design Loading - Exposure Category B - Soil Type Clay
HHD
Allowable Design Loading - Exposure Category B - Soil Type Sand
HHD
Allowable Design Loading - Exposure Category C - Soil Type Clay
HHD
Allowable Design Loading - Exposure Category C - Soil Type Sand
Foundation
Drawings - Type A thru G
Foundation
Type A -- Solid Block
Foundation
Type B -- Pad & Pier / Solid Block
Foundation
Type C -- Pad & Pier / Solid Block
Foundation
Type D -- Pad & Pier / Solid Block
Foundation
Type E -- Pad & Pier / Solid Block
Foundation
Type F -- Pad & Pier / Solid Block
Foundation
Type G -- Pad & Pier / Solid Block
TIA 222-G
- Annex F - Presumptive Soil Parameters
TIA
222-G_Annex F_Presumptive Soil Parameters
Design Comparison
- AN Wireless Tower and the Trylon Titan Tower - Performed by Tower Engineering
Professionals, Inc.
HTML
Version of Design Comparison Report
PDF
Version of Design Comparison Report 3.6 MB
