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ANSl/TIA/ElA-222-f-1QQ6
Approved:
March 29, 1996
TIdEIA
”
STANDARD
Structural Standards for Steel Antenna
Towers and Antenna Supporting
Structures
.
TIAIFJA-222-F
(Revision of ELUTLbZZf-E)
JUNE 1996
TELECOMMUNICATIONS
&WUSlRYASWCUllON
INDUSTRY ASSOCIATION
.
i -= =
m=
ws
.
Reproduced By GLORAL
ENGINEERING DOCUMENTS
WlthlhePetrniuion01EiA
Under Roy&y A~mement
June 10, 1996
TO:
Recipients of new TIA Standards and Engineering Publications
Enclosed please find one copy of the following TINEIA Standard:
TINEIA-222-F
Structural
Supporting
Standards
Structures
for Steel Antenna
Towers
and Antenna
Additional copies of this Standard may be obtained from the Global Engineering Documents,
’ I.S.A. and Canada (l-800-854-7179)
International (303)-397-7956 at a price of $80.00 each.
Sincerely,
Cecilia tie&g
Engineering Department
enclosure
Remmng
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NOTICE
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regulatory requirements. It is the responsibility of the user of this Standard to establishappropriate
safety and kahh practices and to determine the applicability of reguIatory limitations before its use.
(From Standards Proposal No. 3278, formulated under the cognizance of the TR-14.7 Structural
Standards for Steel Antenna Towers and Antenna Supporting Structures Subcommittee
.
Published by
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STRUCTURAL STANDARDS FOR STEEL ANTENNA TOWERS
AND
ANTENNA SUPPORTING STRUCTURES
!O
CONTENTS
Section
Page Number
OBJEC’TWE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
SCOPE...............................................................
1
MATERIAL ........................................................
1.1 Standard .......................................................
1
LOADING
2
1
.........................................................
2.1 Definitions ...........................................
2.2 Nomenclature for Section 2 Loading ................................
2.3 Standard .......................................................
3
a
4
4
11
3.1 Standard .......................................................
11
MANUFACTURE
18
5 FACTORYFINISH
AND WORKMANSHIP
11
..............................
.........................
...................................................
5.1 Standard .......................................................
6 PLANS, ASSEMBLY TOLERANCE& AND MARKING
18
18
18
...................
6.1 Standard ........................................................
7 FOUNDATIONS AND ANCHORS .....................................
7.1 Definitions.. ...................................................
18
18
19
19
7.2 Standard .......................................................
19
7.3 Special Conditions ...............................................
7.4 FoundationDrawings ............................................
i0
8 SAFE‘TY FACTOR OF GUYS .........................................
8.1 Defmition ......................................................
8.2 Standard..........................~
”
3
2.4 References .....................................................
STRESSES .........................................................
4.1 Standard.............................~
*
2
..........
............................
9 PRESTRESSING AND PROOF LOADING OF GUYS .....................
9.1 Definitions.. ...................................................
9.2 Standard .......................................................
21
21
21
21
21
21
22
TIAEIA-222-F
CONTENTS (Continued)
c
,
a
Page Number
10 INITIAL GUY TENSION , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
22
10.1 Definition ......................................................
22
10.2 Standard .......................................................
Section
10.3 Method Of Measurement ..........................................
11 OPERATIONAL REQ IJ-mMmTs
....................................
11.1 Definitions ...... ...............................................
11.2 Standard .......................................................
12 PROTECTIVE GROUNDING .........................................
12.1 Definitions .....................................................
12.2 Standard .......................................................
13 ~JMJXPG AND WOlSKING FACILITIES ..............................
13.1 Definitions ...... ...............................................
13.2 standard .......................................................
14 -PWI’KE
AND INSPECTION
..................................
14.1 Standard .......................................................
15 ~A.LxIS
OF EXKI’ING TOWERS AND STRUCTURES .................
15.1 Standard.............................\
.........................
16 COUNTY LISTINGS OF MINMLJMBASIC
WIND SPEEDS ...............
22
22
22
22
23
23
23
23
23
23
24
24
24
24
25
ANNEXES
Annex A:
Annex B:
Annex C:
Annex D:
Annex
Annex
Annex
Annex
E:
F:
G:
H:
Annex I:
Annex J:
PU-KI-WER CHECKLIST ..................................
DESIGN WIND LOAD ON TYFICAL MICROWAVE
ANTENNAS/REFLECTORS
.................................
TABLE OF ALLOWABLE TWIST AND SWAY VALUES FOR
PARABOLIC ANTENNAS, PASSIVE REFLECTORS, AND
PERISCOPE SYSTEM REFLECTORS . . . . . . . . . . . . . . . . . . . . . . . . .
59
61
71
DETERMINATION OF ALLOWABLE BEAM TWJST Am SWAY
FOR CROSS-POLARIZATION LIMITED SYSTEMS . . . . . . . . . . . . . 77
TOWER MAINTENANCE AND INSPECTION PROCEDURES . . . . 83
CRITERIA FOR THE ANALYSIS OF EXISTING STRUCTURES . . . 101
SI CONVERSION FACTORS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
COwmY
ON ICE DESIGN CRITERIA FOR
CO-CATION
STRUCTURES.. . . . . . . . . . . . . . . . . . . . . . . . . . 105
GEOTECHNICAL JJqVESTIGAnONS FOR TOWERS . . . . . . . . . . . . ,109
CORROSION CONTROL OPTIONS FOR GUY ANCHORS
IN DIRECT CONTACT WITH SOIL . . . . . . . . . . . . . . . . . . . . . . . . . . 111
STRUCTURAL STANDARDS FOR STEEL ANTENNA TOWERS AND
ANTENNA SUPPORTING STRUCTURES
OBJECTIVE
The objective of these standards is to provide I&,&=
uitezia for specifying and designing steel
antenna towers and antenna supporting structures. These standardsare not intended to replace or
supersede applicable codes. me information contained in these standards was obtained from
sources as referenced and noted herein and represents, in the judgement of the subcommittee, the
accepted industry practices for minimum standardsfa the design of steel antenna suppohg
structures. It is for general information only. while it ia believed to be accurate, this information
should not be relied upon for any specific application without competent professional examination
and verification of its accuracy, suitability, and applicability by a licensed professional engineer
These standards utilize wind loading criteria baaedon an annual probability and are not intended to
cover
d environmental conditions which could exist at a particular location.
These standards apply to steel antenna towers and antenna supporting structures for all classesof
cmmmications service, such as AM, CATS, FM, Microwave, Cellular, TV, VHF, etc.
These standards may be adapted for international use; however, it is necessary to determine the
appropriate basic wind speed (fastest-mile) and ice load at the site location in the specific co~npy
based on local meteorological data.
Equivalent International System of Units (SI) are given iu brackets [ ] throughout these standards.
SI conversion factors have been provided in Annex G.
It is the responsibility of the purchaser to provide site-specific data and requirements differing from
those contained in these standards.
Annex A provides a checklist for assisting the purchaseri.nspecifying the requirements for a specific
structure when using these standards..The user is cautioned that local conditions of wind and ice, if
known, have precedence over the minimum standardsdescribed herein.
SCOPE
These standards describe the requirements for steel antenna towers and antenna supporting
stnmures.
1
MAIERIAJd
1.1
Standard
1.1.1 Material shall conform to one of the following standards except as provided in 1.1.2.
1.1.1.1 Structural
steel, cast steel, steel forgings, and bolts shall confom~ to the material
specifications listed in the June 1, 1989, American Institute of Steel Constmction,
“Specification for Structural Steel Buildings - Allowable Stress Design and Plastic
Design”, hereinafter referred to as the AISC specification.
1.1.1.2 Light gauge steel stmctural members shall be structural quality as defined by the
August 19, 1986, American Iron and Steel Institute, “Specification for the Design of
Cold-Formed Steel Stmctural Members”, hereinafter referred to as the AISI spe@fication.
1.1.1.3 Material for tubular steel pole structures and components shall conform to section
7.0 of A.NSI/NEhtA TTl- 1983, “Tapered Tubular Steel Structures”.
-
--
-
-1.
l
----I
1.1.2 When materials other than hose specified herein are used, the supplier must Provide
certified data concerning mechanical and chemical properties.
1-1-3
Bolts and nut locking devices (excluding guy hardware).
Sl.@xitical coM&o~
md ~nnections subjected to tension where the
application of externally applied load results in prying action produced by deformation of
the connected parts sha.Ube m& v&h b&h-strength bolts tightened to the miuimum bolt
tensions specified in the November 13, 1985, AISC, “Specification for Structural Joints
using ASTM A325 or A490 Bolts”.
1.1.3.1
EepbOn: where it can be shown that the stiffness of the connected parts is sufficient to
rtth= prying forces to ittsignifrcauce, tension connections may be made with high-strength
bolts tightened to a snug-tight condition as defined in the AISC specification refened to in
1.1.3.1.
(Note: Contact surfacesfor slip-critical connectionsshall not be oiled or painted and for
galvanized material, the contact surfaces shall be prepared in accordance with the DISC
specification referred to in 1.1.3.1.)
1.1.3.2 Bearing-type connections may be made with high-strength bolts tightened to a
snug-tight condition as defined in the AIsC specification referred to in 1.1.3.1.
1.1.3.3 Where high-strength bolts are used and tensioned in accordance with the mc
specification referred to in 1.1.3.1, a nut-locking device is not required.
1.1.3.4 Bolts not covered in 1.1.3.3 require a nut-locking device.
-
1.1.3.5 Hot-dip galvan&& A490 bolts shall not be used.
1.1.4 Materials other than steel are not within the &ope of this section.
2
LOADING
2.1
Definitions
2.1.1
Dead Load - The weight of the structure, guys. and appurtenances.
2.1.2 Ice Load - The radial thickness of ice applied uniformly around the exposed surfacesof
the structure, guys, and appurtenances.
2.1.2.1 Unless otherwise indicated, a specified radial ice thickness shall be considered as
solid ice.
2.1.2.2 The density of solid ice shall be considered to be 56 lb/f9 18.8 kN/m3].
2.1.2.3 The density of rime ice shall be considered to be 30 lb/@ [4.7 kN/m3].
2.1.3
Wind Load - The wind loading requ&ments specified in 2.3 (see Annex A).
2.1.3.1 Basic Wind Speed - Fastest-de wind speed at 33 ft [lo m] above ground
corresponding to an annual probability of 0.02 @O-yearnmrrence interval).
2.1.4 Appurtenances - Items attached to the structure such as m*MaS,
transmission lines,
conduits, lighting equipment, climbing devices, platforms, signs, anti-climbing devices, etc.
2.1.4.1 Discrete Appurtenance concentrated at a point.
An appurtenance whose load can be assumed to be
I)
2.1.4.2 Linear Appurtenance - An appurtenance whose load can be assumed to be
distributed over a section of the structure.
Nomenclature for Section 2 Loading
2.2
0
0
AA
Projected area of a &near appurteuance
AC
Projected area of a &Crete appurtenance
42
Effective projected area of structural components in me face
AF
Projected area of fit structural componeuts in one face
AC
Gross area of one tower face as if the face were solid
AR
Projected area of round structural components in one face
C
Velocity coefficient for tubular pole structure force coefficients
CA
Linear or discrete appurtenance force coeffkient
CD
Guy hag force coeffkient
CF
Structure force coefficient
CL
GUY lift force coefficient
D
Dead weight of the structure, guys, and appurtenances
.?F
Wind direction factor for flat structural components
DP
Average diameter or averageleast width of a tubular pole stmctm
DR
Wind direction factor for round structural co&ponents
F
Horizontal force applied to a section of the structure
FC
Design wind load on a discrete appurtenance
FD
Total drag force on a guy
FL
Total lift force on a guy
@I
Gust response factor for fastest-mile basic wind speed
I
Weight of ice
Kz
Exposure coefficient
Lc
Chord length of guy
RR
Reduction factor for round structural components
V
Basic wind speed for the structure location
WI
Design wind load on the structure, appurte~ccs,
WO
Design wind load on the structure, appurtenmccs, gUY%e% without ice
d
Diameter of guy strand
e
Solidity ratio
@Ys, etc.9with radial ice
2.3
h
Total height of structure
92
Velocity pressure
r
Ratio of comer diameter to diameter of inscribed circle of a tubular pole structure
t
Radii thickness of ice
Z
Height above average ground level to midpoint of section, appurtenance or gUY
8
Clockwise angle from guy chord to wind direction vector
Standard
2.3.1
Wind and Ice Loads
2.3.1.1 The total design wind load shall include the sum of the horizontal forces applied to
the structure in the direction of the wind and the design wind load on guys and discrete
appurtenances.
231.2
This standard does not specifically state an ice requirement. Ice loading,
depending on tower height, elevation, and exposure, may be a significant load on the
stnmure in most parts of the United States. If the structure is to be located where ice
accumulation is expected, consideration shall be given to an ice load when specify& the
requirements for the structure. (Refer to Annexes A and H.)
2.3.2 The horizontal force (F) applied to each section of the structure shall be calculated from
the equation:
F=qzGHCCFAE+~(CAAP31(lb>N
;
Not to exceed 2 QZG &
where AC = Gross area of one tower face (ft2) [m2]
(Note: All appurtenances, including antennas,mounts and lines, shall be assumedto remain
intact and attached to the stmcture regardless of their wind load capacities.)
2.3.3 The velocity pressure (Q) and the exposure coeffkient (K3;) shall be calculated from the
equations (see Annex A):
Q = -00%
Kz V2 (lb/ft2) for V in mi/h or
qz=.613KzV2PJforVinm/s
Kz = M3312” for 2 in ft or
Kz = Cx/1012nfor 2 in meters
1.00 2 Kz < 2.58
V = Basic wid speed for the structure location (mi/h) Cm/s1
z = Height above average ground level to midpoint of the section (ft) [ml
2.3.3.1 Unless otherwise specified, the basic wind speed W) for the structure location shall
be determined from section 16.
2.3.4
Gust Response Factors
2.3.4.1 For latticed structures, the gust response factor (GH) shall be calculated from the
equation:
&I = .65 + .6O/(h/33)’ I7 for h in ft or
%I = .65 + .60&h/10)’ I7 for h iu meters
1.00 2 G-JJ< 1.25
2.3.4.2 For tubular pole structures, the gustresponse factor (GH) shall be 1.69.
2.3.4.3 One gust response factor shall apply for the entire structure.
2.344 When cantilevered tubular or latticed pole structures are mounted on latticed
structures, the gust responsefactor for the pole and the latticed structure shall be basedon the
height of the latticed structure without the pole. The stressescalculated for pole structures
and their connections to latticed structures shall be multiplied by 1.25 to compensatefor the
greater gust response for mounted pole structures.
23.5
Structure Force Coefficients
2.3.5.1 For latticed structures, the structure force coefficient (CF) for each section of the
mct~e shai.i be calculated from the equations:
CF = 4.0e2 - 5.9e + 4.0 (Square cross sections)
CF = 3.4e2- 4.7e + 3.4 (Triangular cross sections)
e = Sdidity Ratio = (AF + AR)/&
:
AF = Projected area (ft2) [rnz] of flat structural components in one face of the section.
AR = Projected area (ft2) [m2] of round structural components in one face of the section
and the projected area of ice when specified on flat and round structural components.
(Refer to Figure 1).
(Note: The projected area of structural components shall include the projected area of
connection plates.)
I 1A1tl.b222-F
t
\
1Ly
I/\\0’-2
t = Specified radial thickness of ice
Figure 1
(Note: Ice, when specified,shall be assumed to accumulate uniformly on all surfacesas
illustrated. The additional projected area caused by the ice accumulation may be
considered cylindrical even though the bare projected area is flat. Consideration shall be
given to the change in shapefrom round to flat for closely spaced linear appurtenances
with ice accumulations.)
2.3.5.2 For cantilevered tubular steel pole structures, the structure force coefficient (CF)
shall be determined from Table 1.
2.3.6 The effective projected area of structural components (AE) for a section shail be
calculated from the equation:
AE = DF AF + DR AR RR (f$) Cm*]
(Note: For tubular steel pole structures, AE shall be the actual projected area basedon pole
diameter or overall width.)
2.3.6.1 The wind direction factors, & and &, shall be determined from Table 2.
2.3.6.2 The reduction factor (RR) for round structural components shall be calculated from
the equation:
RR = .51e2 + .57
RR < 1.0
2.3.6.3 Linear appurtenances attached to a face and not extending in width beyond the
normal projected area of the face may be considered as structural components when
calculating the solidity ratio and wind forces.
TIAEIA-222-F
Table 1
Force Coefficients (CF) for Cantilevered ‘Ihbular Pole Structures
Round
1.20
32 to 64
16 Sided
r > 0.26
12 Sided
8 Sided
1.20
1.20
1.20
1.20
125
1.20
.72
1.03
1.20
I
1
~32
16 Sided
r < 0.26
130
013
w
22.9
915
1.78 + 1.4Or-cm
J2+(64-C)
am&
. 44.8
t
1.08 - 1.4Or
59
>64
SI Units
< 4.4
4.4 to 8.7
Round
16 Sided
r < 0.26
16 Sided
r > 0.26
12 Sided
8 Sided
1.20
1.20
1.20
1.20
1.20
3.78
1.20
9.74
1.78+ 1.4Or
(Cl I3
VDp
3%
.
.72 +(8k7;ooc)
.
.72
1.08 - l&r
59
> 8.7
C = &
-+5
-
Q.6
1.03
1.20
forDpinft[m]
Notes:
1. The above force coefficients apply only to cantilevered tubular pole structures which
stand alone or are mounted OIIthe top of a latticed strwture.
2. The force coeffkients indicated account for wind load reductions under supercritica.l flow
conditions and therefore do not apply to appurtenances attached to the structure. Use Table 3 for
appropriate force Coeffkients for appurtenances.
3. For ail CTOSS
sectional shapes, Cf need not exceed 1.2 for any value of C.
4. V 1sthe basic wind speed for the loading condition under investigation.
Table 2
Wind Direction Factors
Tower Cross
Section
DR
Square
1.0
1+.75e (1.2 max)
* Measured from a line normal to the face of the structure
1.0
1.0
1.0
TWEIA-222-F
The force coefficient (CA) appkd to the projected area (ft2) [m21of a hxr
app~enance
(AA) not considered as a ~~~ctural component shall be determined from Table 3.
0
The force coefficient for cyli&$c~ members may be applied to the additional projected area of
radial i= when specified. (Refer to Figure 1.)
2.3.7
Table 3
Appurtenance Force CoeffkieMs
AspectRatio 5 7
Member Type
Flat
cylindrical
I
AspectRatio> 25
CA
1.4 *
2.0
0.8
1.2
CA
Aspect Ratio = Overti length/width ratio in plane normal to wind direction. (Aspect rstio is not
a function of the spacing between support points of a linear appurtenance, nor the section length
force.)
ccmidered to have a uniformly distributed
Note: Linear interpolation may be used for aspect ratios other than shown.
2.3-g Regardless of location, linear appurtenancesnot considered as structuraI components in
accordance with 2.3.6.3 shall be included in the term C CA AA.
2.3.9 The horizontal force (F) applied to a section of the structure may be assumed to be
mi.f~nnly distributed based on the wind pressure at the mid-height of the section.
2.3.9-l For guyed masts, the section considered to have a uniformly distributed force shall
not exeed the span between guy levels.
2.3.9.2 For free-standing structures, the section considered to have auniformly distributed
for= shad not exceed 60 ft [ 18 m].
2.3.9.3 For tubular steel pole structures, the section considered to have a uniformly
deputed force shall not exceed 30 ft [9.1 m].
2.3.10 In the absence of more accurate data, the design wind load (Fc> on a discrete
appurtenance such as an ice shield, platform, etc. (excluding microwave antennas/passive
reflectors) shall be calculated from the equation:
where x CA AC considers all elements of the discrete appurtenance including any feed lines,
brackets, etc., related to the appurtenance. Components of a discrete appurtenance attached
directly to a tower face and not projecting away from the face may be considered as
structural components when c&dating the solidity ratio and wind forces.
2.3.10.1 The velocity pressure (9z> shall be c&ulated based on the centerline height of the
appurtenance.
0
TWEIA-222-F
2.3.10.2
The gust response factor (GH) shall be calculated based on the total height of the
stmtm
for latticed structures (see 2.3.4.4) and shall be equal to 1.69 for tubular Pole
smctures.
2.3.10.3 The design wind load (Fc) shall be applied in a horizontal direction in the direction
of the wind.
2.3.10.4 The force coefficient (CA) applied to the projected area (fP) Cm21of a discrete
appurtenance (AC) shah be determjncd f&r Table 3. The farCe coefficient for Cysts
members may be applied to the cylindrical portions of the appurtenanceand to the additional
projected area of ice when qecifred. (Refer to Figure 1).
2.3.10.5 When an equivalent flat-plate area based on Revision C of this standard (AF +
2/3 AR) is provided by a manufacturer of an appurtenance, a force coefficient of 2.0 must be
applied to the equivalent flat-plate area when determiktg design wind loads. When the
appurtenance is made up ofround members only, a force coeSzient of 1.8 may be applied.
2.3.11 In the absence of more accurate data, the design wind load on microwave
antennas/passive reflectors shall be determined using Annex B.
2.3.12 When the azimuth orientations of antennaslocated at the samerelative elevation on the
stmctu.re are not specified, the antennas shall be assumed to radiate symmetrically about the
structure.
23.13
shielding of antennas shall not be considered.
2.3.14 The design wind load on guy& shall be determined in accordance with Figure 2. The
design wind load may be assumed to be uniform based on the velocity pressure (sz> at the
.
midheight of each guy.
2.3.15 The maximum member s&sses and structure reactions shall be detexmined considering
the wind directions resulting in maximum wind forces and twisting moments. Each of the wind
directions indicated in Table 2 shall be considered for latticed structures. .
2.3.16 Each of the following load combinations shall be investigated when calculating the
maximum member stressesand smcture reactions (see Annex A):
D+Wo
D+.75W1+1
(Note: When the basic wind speed is specified as ocmning simultaneously with an ice load by
the purchaser or local authority, no reduction factor shall be applied to WI.)
Wind Forceson Guys
FD = 9~ GH CD d Lc = Total drag force (lb) [NJ
FL=qzGHCLdLc=Totalliftforce(lb)
N
Q = Velocity pressure at mid-height of guy (lb/ft2) PAJ (see 2.3.3)
k = Gust response factor based on total height of structure (see 2.3.4)
d = Diameter of guy strand (ft) [m]
Lc = Chord length of guy (ft) [m]
0 = Clockwise angle from guy chord to wind direction vector (0 5 180’)
CD = 1.2 sin3 8
CL = 1.2 sin28 cos 8
Figure 2
2.4
References
AAsH”lQ “Standard Specifications for Structural Supports for Highway Signs, LumGres atid
Traffic Signals”, Ar~~erican Asso&~on of State Highway and %UlSpOrdOn
Offici&
wash.@ton, DC., 1985 with 1988 interim ~pecitication~.
ma,
“‘Minirn~m Design Loads for &&iiugs and Other SUUCUIXS”, Ace 7-93, An&can
Society of Civil Engineers, New York, NY, 1993.
DieU W.S., “Engineering Aerodynamics”, Revised Edition, Ronald Rress Co., New York, NY,
1936.
IAs% “Recomnendatio~ for Guy& ~ast$‘, ~temati~nal Association for Shell and Spatial
S~c~eS, working Group Nr 4,1981.
LOU, T., ‘Force coefficients
for ‘hnanission Towers”, A Master Research Report in Civil
&&=-i.ng,
Department of Civil Engineering, Texas Tech University, Lubbock, TX, 1983.
sfiu,
E., changery, MJ., and Fil,liben, J.J., ‘Exueme Wmd Speeds at 129 Stations in the
Contiguous United States”, Building Science Series Report 118, National Bureau of Standards,
Washington, D.C., 1979.
3
STRESSES
Standard
3.1
3.1-l Unless otherwise noted, structural members shall be designed iu accordance with the
appropriate AISC or AISI specification.
3.1.1.1 For structures under 700 ft 1213m] iu height, allowable stressesmay be increased
l/3 for both load combinations defined in 2.3.16.
3.1.1.2 For structures 1200 ft [366 m] or greater in height, allowable stressesshall not be
increased.
3.1.1.3 For structures between 700 ft 1213 m] and 1200 ft [366 m] in height, allowable
stressesmay be increased by linear interpolation between l/3 and 0.
(Note: For structures 1200 ft [366 m] or greater in height, increasesin allowable stressesdo
not apply due to the uncertainties of the wind effects above this height.)
3.1.1.4 Stnxture height, for purposes of determimn g allowable stresses,shall be based on
the total structure height including tubular or latticed poles mounted on the structure.
3.1-l .5 Refer to 2.3.4.4 for stressincreasesrequired for cantilevered tubular pole structures
mounted on latticed strucme~.
3.1.2 For guyed structures, the displacement of the mast at each guy level shall be considered
wilen computing stresses.
3.1.3 The end connection and intermittent filler mqrimments of section E4 of the AI!K
specification for double angle members need not be satisfied when the slendernessratio for the
buckling mode involving relative deformation between the angles is modified as follows when
determining allowable stresses:
.
. .
.
_..
-
em-
.
where
KL
(To 1
= column slenderness of built-up member acting as a unit about the axis
evolving relative deformation
a
RI
= largest column slenderness of individual components
(F,)
= modified column slenderness of built-up member
a
= distance between connectors
4
= minimum radius of gyration of individual component
3.1.4 A reduction coefficient equalto .75 shall be used when calculating effective net areasin
accordance with section B3 of the AISC specification for angle members and other similar
members connected by one leg with one or two fasteners.
3.1.5 The reduction factor of 3.1.4 does not apply to the required investigation of block shear
in accordance with section J4 of the AISC specification. Net shear and tension areas shall be
based on hole diameters l/16 inch [1.6 mm] larger than bolt hole diameters.
3.16 Bolt holes shall not be considered pin holes, as referred to in section D3 of the AISC
specification.
3.1.7 Deformation around bolt holes shall be a design consideration for the purposes of
calculating allowable bearing stressesin accordancewith section J3.7 of the AISC specification.
3.1-g Table J3.5 of the AISC specification shall ‘apply except at sheared edges where the
minimum edge distance shall be 1.5 times the bolt diameter.
3.1.9 The measured unsupported length of a compression member shall be determined
considering the rigidity of the connected parts and tbe direction of buckling about the axis under
consideration.
3.1.10 Jn computing allowable stresses,when effective length factors are considered less than
1.00 for leg members or members whose ends are attached by a single bolt, justification of each
factor must be shown by test or computation.
3.1.11 For a guyed structure, the stability of the structure between guy levels shall be
considered when calculating allowable member stresses.
3.1.12 Limiting values of effective slenderness ratios for compression members shah
preferably be 150 for legs, 200 for bracing, and 250 for redundants (members used solely to
reduce slenderness of other members).
3.1.13 Bracing and redundants utilized to reduce the slendernessratio of compression members
shall be capable of supporting a force normal to the supported member equal to 1.5 percent of the
supported member’s calculated axial load. This force is not to be applied simultaneously with
the forces resulting from loads applied directly to the StruCttKe.
3.1.14 Structural Steel Single Angle Compression Members
3.1.14.1 Allowable compression stressesshall be calculated in mce
with the ABC
“Specification for Allowable Stress Design of Single Angle Members” except that the
flexurahorsional buckling provisions do not apply.
3.1.14.2 Members subjected to lateral loads, which induce bending, shall meet the
PrO~SiOnsof section 6 of the AISC specification referred to in 3.1.14.1.
3.1.14.3 Effective length factors shall be calculate&n accordancewith ANSYASCE 10-90,
‘Design of Latticed Steel Transmission Towers”, hereinafter referred to as AXE 10, (See
Table 4).
(Note: The effective length factors established in ASCE 10 have been adopted to adjust the
ABC allowable compression stressesfor the effects of eccentric axial loading and partial
end restraint.)
3.1.14.4 Effective length factors, other than those specified herein, shalI be substantiated by
kStS.
3.1.14.5 Slenderness ratios (L/R) shown in Figures 3 and 4 shall be uti.Iized as a guide to
cWmine measured and effective slendernessratios.
3.1.14.6 Members shall be considered fully effective when the ratio of width to thickness
(w/t) is not greater than the limiting value specified in A!XE 10.
3.1.14.6.1 When width-thickness ratios exceed the limiting value, allowable stresses
shall be reduced in accordance with section 4 of the AISC specification referred to in
3.1.14.1 with Q equal to the value calculated for Fcr in AXE 10 divided by the yield
.
stress of the member.
3.1.14.6.2 The width w for cold-formed angles shall equal the distance from the inside
bend radius to the extreme fiber but not less than the angle width minus three times the
angle thickness.
3.1.14.6.3 Width-thickness ratios (w/t) shall not exceed 25.
3.1.14.7 ASCE 10 effective slenderness curves 5 and 6 of Table 4 shall be restricted to
bracing and redundant members with multiple bolt or properly detailed welded connections.
In addition, connections must be to membefi having adequate flexural strength to resist
rotation of the joint including the effects of gussets.
3.1.14.8 Where eccentricity at a joint cannot be avoided, due consideration shall be given to
the additional stressesintroduced in the members.
3.1.15 For tubular pole structures, the secondary bending moments caused by vertical loads
shall be considered when computing stresses.
3.1.15.1 Allowable combined bending and axial stresses for polygonal tubular steel pole
structures shall be determined from Table 5.
TIAEIA-‘22-F
Table 4
lo-90
ANSI/ASCE
EFFECTIVE
SLENDERNESS
CURVES l-3
4 I
CURVES
CURVES 4-6
k>
120
CURVE 4
CURVE 1
KL=L
R
KL
-=R
R
(CONCENTRIC BOTH ENDS)
R
30 + .75k
(ECCENTRIC ONE W>
CURVE
KL
R
60
+ SO:
(ECCENTRIC BOTH ENDS)
5
-I-.762 i
(PARTIAL
RESTRAINT
ONE
END)
KL
-=
R
,28.6
CURVE6
CURVE 3
-=
L
R
\ (NO END RESTRAINT)
CURVE 2
KL
-=
120
KL
-=
R
46.2 + A15 k
(PARTIAL RESTRAINT BOTH ENDS)
TIAXIA-Z-F
SINGLEANGLECOMPRESSION MEMBERS
SLENDERNESSRATZOSFORLEGBRACING
SYMMETRICAL BRACING
CRlTICAL
MEASURED SLENDERNESS RATIO:
4
EF’FEC’IWE SLENDERNESS RATIOS:
L
I
120
L
RZ
CURVE 1
> 120
RZ
CURVE 4
STAGGEREDBRACING
.
Y
x
CRITICAL
MEASURED SLENDERNESS RATIOS:
L
R,
, &
,‘OR
(’ :‘,),,
EFFECTIVE SLENDERNESS RATIOS:
i
MAX I
CURVE 1
120
k MAX > 120
CURVE 4
NOTE:
FOR LEG MEMBERS, MEASURED
EQUAL TO THE PANEL SPACING
AXIS OF THE LEG.
Figure 3
LENGTH (L) SHALL BE
MEASURED ALONG THE
TIAEIA-222-F
SINGLE ANGLE COMPRESSIONMEMBERS
SLENDERNESS RATIOS FOR BRACING MEMBERS
REFER TO SECTION 3.1.9 FOR
DETERMINAnON OF MEASURED LENGTHL
Lu=L1+5U
a
7
CURVE2
*
1
CRrIIcALMEAsuRED
SLENDERNESS RATIO:
%
EFFEm
CURVE4
L,
RX
ORe
sLEyRNEss
Iwtios:
i MAX 5 120 g > 120 u > 120
RZ
cLJRvE2
CLiRVE6
CURVE5
Ll > L2
Lx=L1+5U
Note:
For bracing members with welded or two or more bolt cxmections, measured length (L)
Shall not be less than the distme between the cemroids Of the ~nnectiolls at each end.
Properly detailed welded c.onnectiom may be considered as providing partial restraint.
Figure
4
3.1.16 The design of reinforced concrete for foundations and guy anchors shall Conform to me
“Building Code Requirements for Reinforced Concrete” (AC1 318-89) issued by the American
Concrete Institute.
3.1.16.1 For structures under 700 ft [213 m] in height, the required reinforced concrete
strength shall equal 1.3 times the full structure reactions produced by each load combination
defmed in 2.3.16.
3.1 J6.2 For structures 1200 ft 1366m] or greater in height, the required reinforced concrete
strength shall equal 1.7 times the full structure reactions produced by each load combination
defined in 2.3.16.
3.1.16.3
For structures between 700 ft [213 m] and 1200 ft 1366m] in height, the required
reinforced concrete strength shall be determined by linear interpolation between 1.3 and 1.7
times the structure reactions.
3.1.16.4 Structure height, for purposes of detennhing required reinforced concrete
sue@& shall be based on the total structure height including tubular or latticed poles
mounted on the structure.
Table 5
Allowable Combined Bending and Axial Stresses for Polygonal ‘lobular Steel Pole
Structurt!s
Compact Sections
F~=.60Fy
Noncompact Sections
FB =
Fy=
t =
w =
16 Sided
‘Fyin ksi
215 c &w/t
c 365
565 < & w/t : 958
FyinMPa
FB -852 Fy (CO - 0.00137 ,& w/t) ksi
FB = .852 Fy (1 .O - 0.000522 ,&w/t) MPa
12 Sided
240
< &w/t
630 < &w/t
FB -870 Fy
FB = .870 Fy
Fyin ksi
< 365
2 958
FyinMPa
(TO - 0.00129& w/t) ksi
(1.0 - 0.000491 ,/&w/t) MPa
8 Sided
260 c &w/t
683 7 &w/t
FB =.852 Fy
FB = .852 Fy
Fyinksi
< 365
2 958
FyinMPa
(TO - 0.00114,/& w/t) ksi
(1.0 - 0.000434 & w/t) MPa
Allowable combined bending and axial stress
Yield strength
Wall thickness
Actual flat side dimension, but not less than dimension calculated using a bend radius
equal to 4t
Note: Equations obtained from EPRI report TLMRC-87-R3, “Local Buckling Strength of Polygonal Tubular Poles”, April 1987.
IIA/klA-122-F
4
MANUFACTURE
4.1
Standard
AND WORKMANSHIP
Manufacturing and worha&ip
shall
be in accordance with CO-@
accept&
standards of the structural steel fabricating industry.
4.1.2 Welding procedures shall be in accordance with the requirements of the aPProPfiate
AISC or AISI specifications.
4.1.1
5
FACTORY FINISH
5.1
Standard
51.1 In the absence of other specific requirements, all materials shall be galvanized (see
Annex A).
5.1.1.1 SUUCtUra.lMate~~
- S~I-UC~~ ~taials shall be galvanized in accordancewith
ASTM A123 (hot-dip). Exceptions may be made when galvanizing in accordance with
ASTM A123 would be potentially detrimental to the structure or its components. Examples
include applications utilizing certain high-sue@ and/or proprietary steels and weldments.
In these cases, an alternative method of corrosion control shall be specsed.
5.1.1.2 Hardware - Hardware shall be galvanized in accordance with ASTM Al53
(hot-dip) or ASTM B695 Class 50 (mechanical).
5.1.1.3 Guy Strand - Zinc-coated guy strand shall be galvanized in accordance with
ASTM A475 or ASTM A5S6.
6
6.1
a
PLANS, ASSEMBLY TOLERANCES, AND MARKING
.
Standard
6.1-l Complete p1a.r~ assembly drawings, or other documentation shall be supplied showing
the necessary marking and details for the proper assembly and installation of the material,
including the design yield strength of the spuctural members and the grade of structural bolts
required.
6.1.2 Tolerances for the proper layout
anchors shall be shown on the plans.
and installation of the material; and the foundations and
6.1.2.1 Plumb - The horizontal distance between the vertical centerlines at any two
elevations shall not exceed 25 percent of the vertical distance between the two elevations.
6.1.2.2 Twist - The twist (angular’ rotation in the horizontal plane) between any two
elevations shall not exceed 0.5Oin 10 feet [3 m] and the total twist in the structure shall not
exceed 5’.
6.1.2.3 Length - For tubular steel pole structures with telescoping joint, butt welded or
flanged shaft connections, the overall length of the assembled structure shall be within plus 1
percent or minus l/2 percent of the specified height.
(Note: Horn reflectors and other types of offset-feed antennas have polarization
performance requirements, which are sensitive to ar+@ar displacement from boresight
direction. Special consideration must be given to the mount, attachment hardware,
installation practice, as well as the support structure, to minimize all contributing factors to
initial skew or offset.)
e
6.1.3 All structural members or welded structural assemblies, except for hardware, shall have
a part number. The part numbers shall correspond with the assembly drawings. The Part number
is to be permanently attached (stamped, welded lettering, stamped on a plate that is welded to the
member, etc.>to the member before all protective coatings (galvanizing, paint, etc.1are aPPhed.
The part number shall have a minimum character height of l/2 in. [13 mm], be legible and
clearly visible to an inspector after erection.
7
FOUN-DAnONS AND ANCHORS
7.1
Definitions
7.1.1 Standard Foundations and Anchors - Structures designed to support the specified loads
defined in Section 2 for normal sod conditions as defined in 7.1.3. Pile construction, roof
msmations, foundations or anchors designed for submerged soil conditions, etc., are not to be
considered as standard.
7.1.2 NonS tandard Foundations and Anchors - Structures designed to support the specified
loads defined in Section 2 in accordance with site specific conditions.
7.1.3 Normal Soil - A cohesive soil with an allowable net vertical bearing capacity of 4000
pounds per square foot Cl92 kPa] and an allowable net horizontal pressure of 400 pounds Per
square foot per lineal foot of depth [63 kPa per lineal meter of depth] to a maximum of 4~00
pounds per square foot 1192 pa].
(Note: Rock noncohesive soils, saturated or submerged soils are not to be considered normal
soil.)
a
7.2
Standard
7.21 Stanchi foundations and anchors may be used for bidding purposes and for
construction when actual soil pa&meters equal or exceed normal soil parameters.
7.22 When standard foundations and anchors are utilized for final designs, it shaU be the
responsibility of the purchaser to verify by geotechnicai investigation that actual site soil
parameters equal or exceed normal soil parameters. (See Annex A.)
7.2.3 Foundations and anchors shah be designed for the maximum structure reactions
resulting from the specified loads defined in Section 2 using the following criteria:
7.2.3.1 When standard foundations and anchors are to be used for constnrction, “normal
soil” parameters from 7.1.3 shall be used for design.
7.2.3.2 When nonstandard foundations and anchors are to be used for construction, the soil
parameters recommended by the geotechnicai engineer should incorporate a minimum
factor of safety of 2.0 against &imate soil strength (see Annexes A and I).
7.2.4
Uplift
7.2.4.1 Standardf oundati ons, anchors, or drilled and belled piers shall be assumedto resist
uplift forces by their own weight plus the weight of earth enclosed within an inverted
pyramid or cone whose sides form an angle of 30’ with the vertical. The base of the cone
shall be the baseof the foundation if an undercut or toe is present or the top of the foundation
base in the absence of the foundation undercut. Earth shall be considered to weigh 100
pounds per cubic foot [16 kN/n$] and concrete 150 pounds per cubic foot [24 kN/m3].
I rA~!zlA-222-F
Straight shaft drilled pien for st&ad
foundations shall have an ultimate skin
friction of 200 pounds per square f00t pa lineal foot of depth [31 kPa per Iineal meter of
d@l to amaximumof 1000 pounds per square foot of shaft surface area 148kpal for upllfr
or download resistance.
7.2.4.2
7.2.4.3 Nonstandard foundations, anchors, ami &i.lkd piers shall be designed in
awodance with the recommendations of a geotechnid report (see Annex I).
7.2.4.4 Foundations,
the following:
anchors, and drilled
shah be proportioned in accordance with
piers
(WR /2-o) + (WC D-25) 2 Up and (wR+wc)/l.5
where:
1 up
WR = soil resistance from 7.2.4.1.7.2.4.2 or 7.2.4.3
WC = weight of concrete
Up = maximum uplift reaction
7.2.4.5 A mat or slab foundation for a seif-supporting structure shall have a minimum
safety factor againstoverturning of 1.5.
7.2.5
The depth of standard drilled foundations subjected to lateral or overturning loads shall
be proportioned in accordancewith the following:
LD 2 2.0 + S/(3d) + 2 [S2/(18d2)+ S/2 + M/(3d)]ln (ft)
LD > .61 + S/(143d) + 2 [S2/(41333d2) + S/96 + M/(143d)11R [ml
where:
LD = Depth of drilled foundation
.
below
grounilevel (ft) [ml
d
= Diameter of dri.Uedfoundation (ft) [ml
S
= Shear reaction at ground level (kips) &NJ
M
= Ovemuning moment at ground level (ft-hips) [m-w
Reference: Broms, B., “Design of Laterally Loaded Piles”, Journal of the Soil Mechanics
and Foundation Division Proceedings of the American Society of Civil Engineers, May,
1965.
7.3
Special Conditions
7.3.1 When a support is to be designed by other than the manufacturer,themanufacturerwill
be responsible for furnishing the reactions, weights, and interface details for the purchaser’s
engineer to provide the necessary attachment.
7.3.2 The effects of the presence of water shall be accounted for in the design of nonstandard
foundations. Reduction in the weight of materials due to buoyancy and the effect on soil
properties under submerged conditions shall be considered.
7.4
Foundation Drawings
7.4.1 Foundation drawings shd indicate structure reactions, material strengths, dimensions,
reinforcing steel, and embedded anchorage material type, size, and location. Foundations
desiped for nomA soil conditions shall be so noted.
(Note: Normal soil design parameters and methods are presented to obtain uniform standard
foundation and anchor designs for bid&g purposes. Design methods for other COnd~OnSand
0t.k foundation types must be consistent with accepted engineering practices.)
8
8.1
SAFETY FACTOR OF GUYS
Definition
8.1.1 Guy Connection - The guy connection is defmed as the hardware or mechanism by
which a length of guy strand is connected to the tower, insulator, or guy anchor. The connection
may include, but is not limited to, the following: shackles, in-line insulators, thimbles,
turnbuckles, twin base clips, u-bolt cable dips, poured socket fittings, and grip- type dead-end
connections. ‘l%vin base and u-bolt chps used on guy strand through 7/8-in. diameter shall be
considered to have a maximum efficiency factor of 90 percent. In all other cases,clips on strand
shall be considered to have a maximum efficiency factor of 80 percent. For all other types of end
connections, manufacturer’s recommendations should be followed when determining the
connection efficiency factor,
8.1.2 Safety Factor of Guys - The safety factor of guys shall be calculated by dividing the
published breaking strength of the guy or guy connection strength, whichever is lower, by the
maximum calculated tension design load.
8.2
Standard
8.21 For structures under 700 ft [213 m] in height, the safety factor of guys and their
connections shall not be less than 2.0.
8.2.2 For structures 1200 ft [366 m] or greater in height, the safety factor of guys and their
connections shall not be less than 2.5.
8.2.3 For structures between 700 ft [213 m] and 1200 II [366 m] in height, the minimum safety
factor of guys and their connections shall be determined by linear interpolation between 2.0 and
2.5.
(Note: A l/3 increase in stress for wind-loading conditions does not apply to the published
breaking strength of guys and their connections.)
8.2.4 Structure height, for purposes of determinin g the required safety factor of all guys and
their connections, shall be based on total structure height including tubular or latticed poles
mounted on the structure.
9
PRESTRESSINGAND PROOF LOADING OF GUYS
9.1
Definitions
9.1.1 Prestressing of Guys - The removal of inherent constructional looseness of the guy
under a sustained load.
9.1.2 Proof Loading connections.
The assurance of mechanical strength of factory assembled end
-
-..
_
_--
a
Standard
9.2
9.2.1 &stressing and proof loading are not normaLly required. When specified. Presnessing
and proof loading shall be performed in accordance with the recornmendati~~ of the gUY
manufacturer.
(Note: For tall, guyed structures, consideration should be given to prestressing and Proof
loading.)
10
10.1
INITIAL GUY TENSION
Definition
10.1-l Initial Guy Tension - The specifieci guy tension in pounds [newtons] under no wind
load conditions, at the guy anchor at the specified temperature (see 10.2).
10.2
Standard
10.2.1 Initial tension in the guys, for design purposes, is normally 10 percent of the published
breaking strength of the strand with upper and lower limits of 15 and 8 percent respectively.
Values of initial tension beyond these limits may be used provided consideration has been given
to the sensitivity of the structure to variations in initial tension and, if necessary, to dynamic
behavior (see note below). Consideration shall be given to the site ambient temperature range.
In the absence of site specific data, the initial tensions shall be based upon an ambient
temperature of 6O*F.
(Note: The stated 8-15 percent initial tension extreme values are provided as recommended
guidelines only. Specific site and terrain conditions may necessitate initial tension values
outside this range. When using initial tension values above 15 percent, consideration should be
given to the possible effects of aeolian vibration. mewise, when using initial tension values
less tha.u g percent, consideration should be given to the effects of galloping and slack-taut
pounding.)
10.3
Method of Measurement
10.3.1 Initial tension may be measured by vibration frequency, mechanical tensiometers,
~eas~~ent
of guy sag, or by other suitable methods (see Annex E).
11
OPERATIONAL REQUIRE,MENTS
11.1
Definitions
11.1.1 Twist - The angular rotation of the antenna beam path in a horizontal plane from the
no-wind load position at a specified elevation.
11.1.2 Sway - The angular rotation of the antenna beam path in a vertical plane from the
no-wind load position at a specified elevation.
11.1.3 Displacement - The horizontal translation of a point relative to the no-wind load
position of the same point at a specified elevation.
11.2
Standard (See Annex A)
11.2.1 Theminim Urn standard shall be based on a condition of no ice and a wind load basedon a
50 mph basic wind speed [22.4 m/s] calculated in accordance with 2.3. The operational
requirements shall be based on an overah allowable 10 dI3 degradation in radio frequency signal
level.
11.2.2 Unless otherwise specified, the operational requirements for
reflector systems shall be determined using Annexes C and D.
12
FWXECITVE
12.1
Definitions
micrOWaVe
antex&
GROUNDING
12.1.1 Grounding - The means of establishing an electrical connection between the structure
and the earth, adequate for lightning, high voltage, or static discharges.
primary Ground - A wnchcting connection between the structure and earth or some
conducting body, which servesin place of the earth.
12.1.3 Secondary Ground - A conducting connection between an appurtenance and the
structure.
12.1.2
(Note: Ground wire should not be encased in the foundation.)
Standard (See Annex A)
12.2
12.2.1
Structures shall be directly grounded to a primary ground.
12.2.2 A minimum ground shail consist of two 98 in. [16 mm] diameter galvanized stee!
ground rods driven not less than 8 ft [25 m] into the ground, 180* apart, adjacent to the stmcmre
base. The ground rods shah be bonded with a lead of not smaller than No. 6 [5 mm] tinned bare
copper connected to the nearest leg or to the metal base of the structure. A similar ground rod
shall be installed at each guy anchor and similarly connected to each guy at the anchor.
12.2.3 Self-supporting towers excee&ng 5 ft [1.5 m] in base width shall have one ground rod
per leg installed as above.
12.2.4 All equipment on a structure shah be connected by a secondary ground.
12.2.5 Remote passive reflectok are exempt from the grounding requirements specified herein.
13
CLMMNG
13.1
Definitions
AND WORKING FACZIUTJES
13.1.1 Climbing Facilities - Components specifically designed or provided to permit access,
such as fixed kkhs, step bolts, or snuctu.ral members.
13.1.2 Climbing Safety Devices - Equipment devices other than cages, designed to minimize
accidental falls, or to Iitnit the distance of such falls. The devices permit the person to ascendor
descend the structure without having to continually manipulate the device or any part of the
device. The climbing safety device usually consists of acarrier, safety sleeves, and safety beits.
13.1.3 Working Facilities - Work platforms and accessrunways.
13.1.4 Hand or Guardrds
facilities to prevent falls.
13.2
- Horizontal barriers erected along the sides or ends of working
Standard
13.2.1 Climbing and working facilities, hand or guardrails, and climbing safety devices shall be
provided when specified by the purchaser. (See Annex A.)
13.2.2 Climbing facilities shah be designed to support a minimum 250 [l.l
concentrated live load.
kN] pound
TIAEIA-222-F
13.2.2.1 When fmed ladders are specified as the climbing facility, they shall meet the
fo~o~g minimum requirements:
a. Side rail spa&g - 12 in. [300 mm] minimum clear width.
b. Rung spacing maximum.
12 in. [30O mm] minimum center-to-center, 16 in. [410 mm]
C. Rung diameter -
5/8 in. [16 mm] minimum.
13.2.2.2 When step bolts are specified, they shall meet the following requirements:
a. Clear Width - 4 l/2 in. [llO mm] minimum.
b. Spacing - 12 in. minimum [300 mm] center to center, alternately spaced, 18 in. 1460
mm1maximum.
c. Diameter - 5/S in. 116 mm] minimum.
13.23 Climbing safety devices shall meet the design requirements of the American National
Standards Institute (ANSI) A14.3-1984, “Safety Requirements for Fixed Ladders”, Se&on 7.
13.24 Support structures for working facilities shall be designed to support a uniform live load
of 25 lb/ft’ Il.2 kpa], but in no case shall the support structure be designed for less than a total
he load of 500 pounds 12.2ItN]. Working surfaces,
such asgrating, shall be designed to support
two 250-pound [ 1.1 IrN] loads. These loads are not to be applied concurrently with wind and ice
loads.
132.5 Hand or guardrails shall be designed to support a minimum concentrated live load of 150
pounds LO.67kN1, applied in any direction.
.
(Note: 13.2 is intended to provide m,i,nimm requirements for new structures. It is not intended
to replace or supersede applicable laws or codes.)
14
-ANCE
14.1
Standard
AND INSPECTION
14.1.1 Maintenance and inspection of steel antenna towers and antenna supporting structures
should be performed by the owner on a routine basis.
(Note 1: It is recommended that all structures be inspected after severe wind and/or ice storms or
other extreme loading conditions.)
,
(Note 2: Recommended inspection and maintenance procedures for towers are provided in
Annex E.)
3: Shorter inspection intervals should be considered for structures in coastal salt water
environments, in corrosive atmospheres, and in areas subject to frequent vandalism.)
(Note
15
ANALYSIS OF EXNING
15.1
Standard
TOWERS AND STRUTS
15.1-l Steel antenna towers and other suppo~g stNctures should be analyzed when changes
occur to the original design or operational loading conditions. Recommended criteria for the
analysis of existing structures are provided in Annex F.
16
COUNTY LISTINGS OF MINIMUM BASIC WIND SPEEDS (SeeAnnex A)
StatedALABAMA
statf! of ALABAMA
c0uNl-Y
AUTAUGA
BALDWIN
BARBOUR
BIBB
BLOUNT
BULLOCK
BUTLER
CALHOUN
CHAMBERS
CHEROKEE
(ZTHIEDN
CHOCTAW
E!tt&mE
COFFEE
COLJ3lXT
CONECUH
COOSA
COVING-l-ON
CRENSHAW
DALE
DALLAS
DEKALB
ELMORE
EscAMBIA
ErowAH
FAYEITE
NOTE*
2
NOTE*
COUNIY
MONROE
MONTGOMEEtY
MORGAN
PERRY
FICKENS
2
2
2
2
2
2
2
2
2
2
BENRY
HOUSTON
JACKSON
JEFFERSON
2
2
LAUDERDALE
LAmcE
2
ii
70
70
70
70
ii:
70
70
85
70
85
ii
80
70
80
70
70
70
90
70
70
70
90
70
70
80
85
70
70
70
70
70
70
70
75
70
70
75
70
70
95
*For notes, see end of Section 16
-
85
Ei
iEFDOiJ?H
RUSSEL
SAINTCLAIR
SHEBY
tiZ!it~GA
TALLAPOOSA
TUSCALOOSA
WALKER
WASHINGION
WILCOX
WINSTON
BASIC WIND
SPEED(MpH)
70
70
2
2
GENEVA
LIMESTONE
LOwNDE!z
MACON
MADISON
MARENGO
MARION
MARSHALL
MOBILE
BASIC WIND
s=ED(Mpm
70
100
75
70
70
2
2
75
70
70
70
70
70
70
70
;
:
70
state of ALASKA
ALEunANIsLANDs
ANCHORAGE
I=?=
BRISTOL BAY
DILLINGHAM
FAlRBANKS NO. STAR
JUNEAU
KENAIFENINSULA
KEKEEANGAXEWAY
KOBUCK
KODIAK ISLAND;
WANUSKA-SUSl’INA
NOME
NORTH SLOPE
PRINCEOFWALES
SIlKA
SKAGWAY-%4KUTflANGOON
SOUTHEASTFAIRBANKS
VALDEZ-CORDOVA
WADEHAMPTON
wRANGELt--URG
YUKON-KOYUKUK
caution: Mound
regicm af
Alaskashouidbecxmsidered~
sYpdaiwin.dregions.
110
110
110
105
105
70
80
90
100
95
100
110
80
110
100
100
100
100
70
90
110
90
90
*
sta!eofARKANsAs
Stateof ARIZONA
COUNTY
NOTE*
APACHE
COCBlSE
cocoNINo
BASIC WIND
BASIC WIND
mED(MpH)
1
1
couIvIY
70
70
70
HOWARD
INDEPENDENCE
E
70
70
75
75
70
75
75
70
75
70
JEFFERSON
JACKSON
FEGAM
LAPAZ
MARICOPA
MOHAVE
NAVAJO
1
PINAL
SANTACFUJZ
YAVAPAI
JOHNSON
WALAWRENCE
IJNCOLN
LmuzRrvER
LOGAN
LONOKE
MADISON
MARION
State of ARKANSAS
ARKANSAS
ASHLEY
BAXIER
BENTON
BOONE
BRADLEY
CALHOUN
CARROLL
CBICOT
CLAY
EkG%!E%
COLUMBIA
CONWAY
CRAIGHEAD
CRAWFORD
CRm-ENDEN
CROSS
DALLAS
DESFIA
DREW
FAULKNER
FUIXON
GARLAND
HEMPSTEAD
HOT SPRING
*For notes,
seeend of Section 16
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
,
MISSISSIPPI
MONROE
MONTGOMERY
NEVADA
NEWIUN
OUACHITA
PERRY
PHILLIPS
P0Ixm-r
PO=
POPE
iiiiEsI
RANDOLPH
sAINrFIuNas
SALINE
scorr
SEARCY
SEBASTIAN
EE
SroNE
UNION
VANBUREN
WASHINGTON
WOODRUFF
NOTE*
SPEEDWR)
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
1 IA/tlA-7”-
stateafcALIFom
state of CALIF0RNr.A
COUNTY
NOTE*
ALAMEDA
ALPINE
AMADOR
BUTTE
CALAVEMS
COLUSA
CONTRA COSTA
DELNORTE
ELDORADO
FRESNO
BASIC WIND
SPEED0
1
1
70
70
70
75
70
75
70
80
75
70
1
1
1
ii
70
70
70
1
1
1
HUMBOLDT
EEi
KINGS
a
LASSEN
LOS ANGELES
MADEwi
1
1
1
MARIPOSA
MENDocmo
MEWED
MODOC
MONO
MONTEREY
NAPA
NEVADA
ORANGE
PLACER
PLUMAS
-IDE
SASANBWO
SANBERNARDINO
SANDIEGO
sANFRANcIsc0
SAN JOAQUIN
SANLUIS OBISPO
sANlkulEo
SANTABARBARA
SANTACLARA
SANTACXJZ
SHASTA
SEE&4
SISKIYOU
SOLANO
SONOMA
1
*For notes, see end
1
1
1
1
1
1
1
1
1
1
1
of Section 16
ii
75
70
70
75
ii:
70
70
70.
70
75
75
70
75
70
70
75
70
70
70
70
70
70
70
70
70
70
75
70
75
75
80
NOTE*
COUNTY
BASIC WIND
SPEED (MPM
70
75
75
80
70
70
70
75
75
state of coLoRAD
ADAMS
ALAMOSA
ARAPAHOE
ARBACA
BENT
BOULDER
CLEARCREEK
CONEIOS
cosm
CROWLEY
CUSTER
DEtTA
DENVER
DOLORES
DOUGLA!3
EAGLE
ET&
FREMONT
GARFIELD
GlLPlN
iiii%iON
BINSDALE
HUERFANO
JACKSON
JEFFERSON
KIOWA
KIT CARSON
85
1
1
1
1
1
1
1
1
1
ii
70
85
85
85
80
85
85
80
80
85
80
70
85
70
85
80
E
80
80
85
85
75
70
1
ii
1
LAPLCA
1
ii
85
80
70
85
F
1 lAftlA-7”-t a--
StateiofFLORIDA
state of COLORADO
COuNlY
NOTE*
LASAMMAS
LINCOLN
LOGAN
MESA
BASIC WIND
SEED0
1
MOFEAT
MONTEZUMA
MONlROSE
MORGm
OlERO
OURAY
PARK
PHILLIPS
PIIXIN
FROWERS
PUEBLO
RIO BLANC0
RIO GRANDE
ROUTT
SAGUACHE
SANJUAN
SANMXGUEL
SEDGWICK
SUMMIT
1.m
WASI-BNGTON
80
E
70
75
80
70
ii
85
70
80
85
80
85
85
1
ii
85
80
70
1
ii
80
85
85
85
85
1
1
stare of CONTvEcl-ICUT
FAIRFIELD
HAKl-FORD
Lrrm
MIDDLESEX
NEWHAVEN
NEWLONDON
TOLLAND
WINDHAM
2
2
1.2
2
2
2
2
2
85
80
80
85
85
85
85
85
State of DELAWARE
2
NEW CASTLE
2
SUSSEX
2
Disnict of COLUMBIA
DISTRICTOF
*For
COLUMBIA
80
75
90
2
75
notes,seeend of Section 16
NOTE*
COUNTY
ALACEIUA
BBAY
BRADFORD
BREVARD
BROWARD
CALHOUN
CHARLOTIE
CnRus
CLAY
COLLIER
COLUMBIA
DADE
DE SOT0
DIXIE
DW&
ESCAMBIA
FLAGLER
GADSDEN
GILCHRIST
GLADES
HAMILTON
HARDEE
BENDRY
.IiiERNANDo
HIGHLANDS
HILLSBOROUGH
HOLMES
fNDIANRlvEEz
JACKSON
JEFFERSON
LAFAYEI-IE
LEON
LTBERTY
MADISON
MANATEE
MARION
MONROE
NASSAU
OKALOOSA
OKEJXHOBEE
2
.
1
2
2
2
2
2
2
2
2
2
2
1
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
;
:
2
BASIC WI-ND
SPEED0
95
90
100
95
105
115
100
105
100
95
110
90
115
105
100
95
100
100
105
95
95
100
105
90
100
105
105
100
105
95
105
95
95
95
100
105
95
100
100
95
105
100
105
120
95
1M)
100
F
1 l&&IA-~-
State of GEORGIA
State ofFLORIDA
COUNTY
NOTE*
ORANGE
OSCEOLA
PALMBEACH
PMCO
PINELLAS
F0I.K
PUTNAM
SAINTJOHNS
SAINTLUCIE
SANTA ROSA
SARASOTA
SEMINOLE
SUMTER
SUWANNEE
TAmOR
UNION
VOLUSIA
WAKULLA
WALTON
WASHINGTON
BASIC WIND
sPEEDo
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
100
100
110
105
105
100
95
loo
105
100
105
100
100
90
100
95
100
100
100
95
State of GEORGIA
APPLING
MKINSON
BACON
BAKER
BALDWIN
BANKS
BARROW
BARTOW
BENHILL
BERRIEN
BIBB
BLECKLEY
BRANTIXY
BROOKS
BRYAN
BULLOCH
BURKE
BUTTS
CALHOUN
CAMDEN
CANDLER
CARROLL
CMOOSA
-TON
2
2
2
2
2
2
2
2
2
*For notes,seeend of Section 16
85
.80
85
80
75
75
75
75
80
80
70
75
90
85
90
85
80
70
75
95
80
70
70
90
95
COUNIY
mAHoocHEE
(ZHtUTOOGA
CBEEIOKEE
CLAY
CLAYTON
CLJNCH
COBB
COFFEE
c0LQm-r
COLUMBIA
COOK
COWEIA
CRAWFORD
CRTSP
DADE
DAWSON
DECQUR
DEKALB
DODGE
DOOLY
DOUGBEKIY
DOUGLAS
=Y
ECXOLS
EFFINGHAM
ELBEEa
EVANS
FANNIN
FAYEITE
FLOYD
FORSYTH
FULTON
GLASCOCK
GLYNN
GORDON
K
HABERBAM
HANCOCK
HAULSON
NOTE*
BASIC WIND
SPEEDm
70
75
70
75
75
70
85
70
80
80
75
80
70
70
75
70
75
90
70
75
75
75
70
80
85
90
75
80
85
70
70
70
75
75
70
70
75
95
70
85
75
75
75
75
75
70
70
75
70
*
TIAEIA-‘22-F
State of GEORGIA
COUNTY
NOTE*
BASIC WIND
sPJ330
HENRY
HOUSTON
it--ON
JASPER
JEFFDAVIS
JEFFERSON
JENKINS
JOHNSON
JONES
iI%E
LAURENS
70
2
2
2
LIBERTY
LINCOLN
LONG
LOWNDES
LUMPKIN
MACON
MADISON
MARION
MCDUFFIE
MCINTOSH
MlTcHEu
MONROE
MONTGOMERY
MORGAN
MURIUY
MUSCOGEE
NEWTON
OCONEE
OGLEl-HORPE
PAULDING
PEACH
PICKENS
PIERCE
PIKE
POLK
PULASKI
PUTNAM
2
QRABUN
RANDOLPH
RICHMOND
ROCKDALE
*For notes, see end of Section 16
State of GEORGIA
I
ii
75
75
80
75
80
75
75
70
85
75
75
90
75
90
85
75
70
75
70
75
95
70
80
80
70
80
75
70
70
75
75
75
70
70
75
90
70
70
75
75
75
70
75
75
70
cow
EEEN
NOTE*
SEMINOLE
SPALOING
2
2
kFE%F
liW3OT
-0
3lxrrNALL
TAnOR
2
zEiz%
THOMAS
2
2
TOOMBS
TOWNS
TROUP
TWIGGS
UNION
UPSON
WAIXER
WAIXON
2
EEEN
WASHlNG’IDN
WAYNE
itziEz
WILCOX
WILKINSON
WORTH
2
BASIC WIND
SPEED (Mm
70
80
85
70
75
70
70
70
75
85
70
80
75
8s
80
85
70
80
70
75
75
70
70
75
75
85
75
75
90
70
80
70
70
75
75
75
75
state OfHAwAlI
HAWAII
HONOLULU
KAUAI
MAUI
80
80
Emi
*
state of IDAHO
COuNm
NOTE*
BASIC WIND
sPEED(Mpm
ADA
ADAMS
BANNOCK
BEARLIKE
BENEWAH
BINGHAM
BLAINE
BOISE
BONNIER
BOBOUNDARY
BUTIE
CAMAS
CANYON
CARIBOU
CASSIA
70
70
70
75
70
70
70
70
70
75
70
70
70
70
75
70
70
70
70
70
70
75
70
70
70
70
70
70
70
70
70
70
75
70
70
70
70
70
70
70
75
70
70
70
CLEARWMER
CUSTER
ELMORE
FREMONT
GOODING
IDAHO
JEFFERSON
JEROME
K00TENAI
L.f%rM
Et2
LINCOLN
MADISON
MINIDOKA
NEZPERCE
ONEIDA
OWYHEE
PAYEITE
POWER
SHOSHONE
TETON
TWINFALLS
VALLEY
WASHINGTON
a
stateof xLLIN01s
I
1
COUNTY
IzE4DER
BOND
BOONE
BROWN
BUREAU
CAUIOUN
CARROLL
~Z~ELPAIGN
CHRISTIAN
.CLAY
CUNTON
COXES
COOK
CRAWFORD
CUMBW
DEKALB
DEWl’IT
DOUGLAS
DU PAGE
EDGAR
EDWARDS
EFFINGHAM
FAYEITE
FORD
FULTON
GALJXlTV
GRUNDY
HAMILTON
HANCOCK
iii%i:SON
BENRY
IROQUOIS
JACJLSON
JASPER
JEFFERSON
JERSEY
JO DAVIESS
JOHNSON
KENDALL
KNOX
*For notes, see end of Section
16
NOTE*
BASIC WIND
SF'EED(Mpm
70
70
70
80
70
75
ii
70
70
ii
70
70
70
75
70
70
75
70
70
75
70
70
70
70
70
70
70
70
70
75
70
75
70
75
75
75
70
70
7@
70
80
70
75
75
75
75
TIAEIA-222-F
stateoflLLINoIs
state of ILLINOIS
COUNTY
NOTE*
BASIC WIND
SPEED0
1
LASALLE
LAWRENCE
LIVINGSTON
LOGAN
MACON
MACOUPIN
MADISON
MARION
MARSHAL;L
MASON
MASSAC
MCDONOUGH
MCBEN-RY
MCLEAN
MENARD
MERCER
MONROE
MONTGOMERY
MORGAN
MOULIRIE
OGLE
PEmIA
PERRY
PIAIT
PIKE
POPE
PULASKI
PUTNAM
RANDOLPH
kG
SAINTCL4IR
SALINE
SANGAMON
SCHLJYBZ
SCOTT
SHEIJ3Y
STARK
STEPHENSON
TAZEWELL
UNION
VERMILION
WABASH
WARRJ3
WASHINGTON
WAYNE
*For notes,seeend of Section 16
80
75
70
75
75
70
70
70
70
70
75
70
70
70
80
70
70
75
70
70
70
ii:
75
70
70
70
70
70
75
70
70
75
70
70
70
70
70
70
75
80
70
70
70
70
;
70
70
NOTE*
CouNn
WHITESIDE
%AMSON
WINNEBAGO
WOODFORD
BASIC WIND
SPE’EDWm
80
75
70
80
75
StatedINDIANA
ADAMS
BARTHOLOMEW
BENTON
BLACKFORD
BOONE
BROWN
CARROLL
CASS
E&ON
CRAWFORD
DAVIESS
DEARBORN
DECQTJR
DEXAL33
DELAWARE
DUBOIS
FAYEI-IE
FLOYD
FOUNTAJN
FUIXON
GIBSON
EEk
HAMIIXON
HANCOCK
HARRISON
HENDRxcKs
HENRY
HOWARD
HUNTINGION
JACKSON
JASPER
JAY
JERER!ZON
JENNINGS
JOHNSON
75
75
70
75
70
70
70
70
75
70
70
70
70
70
70
70
75
70
70
75
70
70
70
70
75
70
70
70
70
70
70
70
70
70
75
70
75
70
70
70
70
;
State ofINDIANA
COUNTY
KNOX
KoscIusKo
LAPORTE
LAGRANGE
NOTE*
StatedINDIANA
BASIC WIND
SPEED0
70
75
75
75
75
70
70
70
75
70
75
70
70
70
75
75
70
70
70
70
70
70
75
70
75
70
70
70
70
75
1
1
LAWRENCE
MADISON
MARION
MARS=
e
iEkE?
MONROE
MONTGOMERY
MORGAN
NEWTON
NOBLE
OHIO
ORANGE
OWEN
PARKE
PERRY
PIKE
PORTER
POSEY
PULASKI
mAM
RANDOLPH
1
RUSH
ST. JOSEPH
SCOTT
SI3Eu3Y
SPENCER
STARKE
STEUBEN
SULLIVAN
STIPPECANOE
TIPTON
UNION
VANDERBURGH
VERMIIUON
VIGO
WABASH
WARREN
WARRICK
WASHINGTON
WAYNE
*For notes, see end of Section
TIAEIA-222-F
:8
70
75
75
70
70
70
70
70
70
70
70
75
70
70
70
70
16
BASIC WIND
NOTE* SF=D(MpH)
COUNTY
State af IOWA
ADAXR
2i?izLE
.APPANoosE
AUDUBON
BENTON
BLACKHAWK
BOONE
BREh4ER
BUCHANAN
BUENAVISTA
BUTLER
CALHOUN
CARROLL
CASS
WAR
cER.RoGoRDo
-0KEE
CHICKASAW
CLARKE
CLAY
CLAYTON
CLINTON
ClUWFORD
DALLAS
DAVIS
DECAI’UR
DELAWARE
DES MOINES
DICKINSON
DUBUQUE
ft%EE
FLOYD
FREMONT
GRUNDY
ZN
HANcocK
80
80
Fl
80
80
ii
80
80
80
80
80
80
80
80
80
80
80
80
80
80
80
80
80
75
80
80
75
80
80
80
80
80
80
80
ix
80
80
80
TlAIEIA-221-F
State dIOWA
State of IOWA
COUNTY
NOTE*
BASIC WIND
sPEEDch4Pm
HARDIN
HARRISON
HENRY
HOWARD
HUMBOLDT
IDA
IOWA
JACKSON
JASPER
JEFFERSON
JOHNSON
JONES
KEOKUK
KossuIH
75
80
80
80
80
80
80
80
80
80
80
80
75
80
75
80
85
80
80
80
80
80
80
80
80
80
80
80
LOUISA
LUCAS
LYON
MADISON
MAHASKA
MARION
MARSHALL
MITCBELL
MONONA
MONROE
MONTGOMERY
MWXKINE
O’BRIEN
OSCEOLA
PACE
PALO ALTO
PLYMOUTH
POC4HONTAS
POLK
POTTAWAmAMlE
P0wl3HlEK
RINGGOLD
SAC
SCOTr
SHELBY
SIOUX
STORY
TAMA
TAnOR
UNION
VANBUREN
WAPEILO
*For notes, see end of Section
ii
80
ix
80
80
80
;z
80
80
85
80
80
80
80
75
80
16
NOTE*
COUNTY
BASIC WIND
SPEEDWH)
WARREN
WASHINGTON
WAYNE
WEBSTER
WJNNBBAGQ
WINNESWOQDBURY
WOKm
WRIGHT
State &KANSAS
.
75
ANDERSON
AKHISON
BARBBR
BARH3N
BOURBON
BROWN
BUILBR
CHASE
CHATAUQUA
CHEROKEE
EEED
EiEkBE
COWLJZY
CRAWFORD
DECATUR
DICKINSON
DONIPHAN
DOUGLAS
EDWARDS
Es
mLswoRlH
iFi
80
80
70
80
80
80
75
70
85
80
80
80
75
80
80
70
ii:
80
80
80
ii:
80
85
85
75
80
85
85
85
85
State uf KANSAS
State of KANSAS
COUNIY
NOTE*
BASIC WIND
SPEED0
=OD
COUNTY
NOTE*
80
85
80
85
80
85
75
HAMILTON
iiEE
HODGA4AN
JACKSON
JEFFERSON
JOHNSON
KINGMAN
KIOWA
LABErIE
=VJZNWORTH
LINCOLN
2i.N
LYON
MARION
MARSHALL
MCPHERSON
MEADE
iEG!iaL
MONTGOMERY
MORRIS
MORTON
NEOSHO
NESS
NOKI’ON
OSAGE
OSBORNE
C7ITAWA
PAWNEE
PHILuPS
POTI-AWATOMIE
RAWUNS
RENO
REPUBLIC
RICE
ROOKS
RUSH
RUSSELL
BASIC WIND
SPEED(MpH)
ii
80
85
85
80
85
85
EEiORD
STANTON
STEVENS
xi
75
85
80
80
70
IHOMAS
TREGO
WABAUNSEE
WUCE
WASHING’IDN
WI-A
WILSON
WOODSON
WYANDm
ii
80
75
85
80
80
80
80
85
75.
80
75
80
85
80
75
85
85
80
80
80
80
85
80
80
85
80
80
80
80
85
85
80
.
ADAIR
gk?zE
gz?iE
CARROLL
EiF
cHRETIAN
--
ii
85
85
80
85
80
85
75
75
75
state of KENTCJCKY
ANDERSON
BALLARD
BARREN
BPilH
BELL
BOONE
BOURBON
BOYD
BOYLE
BRACKEN
BRJXBllT
BRECKINRIDGE
J3~ll-r
BUTLER
*For notes,seeend of Section 16
ii
85
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
.
- -- I rrr\-;,-r
ScateOfICENRJ=Ky
state OfKENTIJcKY
COUNTY
NOTE*
BASIC WIND
SPEEDt-Mm
EF
CLINTON
cxrITmDEN
CUMBERLAND
DAVIESS
EDMONSON
ELIOTI-
70
FUIXON
GALILMTN
GARR4RD
zz
:
70
70
70
70
70
70
70
70
70
70
70
70
70
GRAYSON
ziEh.JP
70
70
HANCOCK
HARDIN
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
FAYFI-IE
FLEMlNG
FLOYD
HARRISON
BENDERSON
BENRY
BICKMAN
HOPKINS
JACKSON
JEFFERSON
JESSAMINE
JOHNSON
KENTON
KNOTT
KNOX
LARUE
LAUREL
LAWRENCE
LESLIE
LErcHER
LINCOLN
LMNGSTON
LOGAN
LYON
MADISON
*For notes,seeend of Section 16
COUNTY
MAGoFFIN
MARION
MARsHAu
MASON
MCCRACKEN
MCCREARY
MCLJXN
iiE!EE
MERCER
MErm
MONROE
MONTGOMERY
MORGAN
MUHLENBERG
NESON
NICHOLAS
OHIO
OLDHAM
iEzi!EY
PENDLETON
PERRY
RYXELL
PULASKI
ROBERTSON
ROCKCASTLE
ROWAN
RUSSELL
SCOTr
SHELBY
SIMPSON
SPENCER
TAYLOR
TODD
TRIGG
TRIMBIX
UNION
WARREN
WASmGTON
WAYNE
WEBSTER
WOLFE
WOODFORD
NOTE*
BASIC WIND
SPEEDtMPH)
TIAIEIA-222-F
StateofLOlJISIANA
COUNTY
ACADIA
BASIC WIND
=oMpR)
NOTE*
2
2
95
ASCENSION
ASSUMPI-ION
i
AVOYELLES
2
m2AmAR.D
2
BlJ3MLLE
BOSSIER
CADDO
CALCASIEU
2
CALDWELL
CAMERON
2
CAIAHOULA
CIAIBORNE
CONCORDIA
DE SOT0
EAST BATON ROUGE 2
EAST CARROE
EASTFELICIANA
2
EVMGELINE
2
IBERIA
2
IBEwILLE
2
JACKSON
JEFFERSON
-ONDAVIS
2
LAEAYEmZ
2
LAPOURCBE
2
LASALLE
LINCOLN
LIVINGSTON
2
MADISON
MOREHOUSE
NiUCBITOCHES
ORLEANS
2
OUACBlTA
PLAQUEMIDEZ
2
PolNTcouPEE
2
RAPIDES
REDRIVER
RICBLAND
SABINE
SAINTBERNARD
2
SAINTCHARLES
2
SAINT-A
SAJNTJAMES
SAINTJOBNTBEBAFTIST
SAINTLANDRY
2
StareofLOUISIANA
1z
loo
85
90
70
70
70
95
75
100
80
NOTE*
COUNTY
;
2
TANciIpAHOA
TENSAS
TERREBONNE
UNION
-ON
VERNON
WASBINGTON
Z~Z~~%NROUGE
wEsTc4RRoLL
WESTFELICIANA
ii
90
2
iii
100
loo
70
105
95
100
105
80
70
100
70
70
75
105
70
105
95
85
70
70
75
105
105
95
100
100
95
end of Section 16
100
105
100
;
ii
105
70
100
85
95
2
ii
2
ii
70
2
2
ii
70
95
State OfMAINE
ANDROSCOGGIN
AROO!XOOK
CLJMBERLAND
BArycocK
KENNEBEC
KNOX
LINCOLN
OXFORD
PENOBSCOT
PIS~AQUIS
SAGADAIIOC
SOMERsEr
WALDO
WASBINGTON
YORK
1 .
80
85
80
75
90
80
85
85
75
85
80
85
80
85
100
80
StatedMARYLAND
ALIEANY
ANNEARUNDEL
BALXIMORE
CAL=
CAROLINE
CARROLL
CEaL
DORCBES-XER
PREDERICK
*For notes, see
2
sAIlwMAK13N
SAINTMARY
SAINTTAZMMANY
BASICWXND
SPEED(MpH)
2
2
2
2
2
2
2
2
2
70
75
75
75
80
70
75
75
80
70
TlA/ELW22-F
StateofMICHlGAN
state OfMttRYLAND
COUNTY
NOTE*
GARREIT
HARFORD
HOWARD
MONTGOMERY
PRINCE GEORGE’S
.
ZEf?kEF:
SOMERsEr
TALBOT
WASHINGTON
wIcoMlc0
WORCBSTER
BASIC WIND
SPEED0
2
2
2
2
2
2
2
2
2
2
2
2
;i
70
75
70
75
75
E
80
HAMPDEN
HAMPSHIRE
MIDDLESEX
NANTUtXET
NORFOLK
PLm0Ul-H
SUFFOLK
WORCESTER
2
12
2
2
2
1.2
2
2
2
2
2
2
2
2
100
70
90
iii
ii
75
90
105
90
95
90
85
State of MICHIGAN
ALCONA
ALGER
ALlEGAN
ALPBNA
ARBNAC
BARAGA
BARRY
BAY
BHNZIE
BERRJEN
BRANCH
CALHOUN
CASS
1
1
1
1
1
1
1
75
75
75
75
75
75
75
75
75
80
75
75
75
75
1
1
1
*For notes, see end of Section
NOTE*
1
1
1
cHARLEvolx
CHEBOYGAN
CBIPPBWA
CLJNTON
QRAWPORD
Dn
DICKINSON
iEi&
BASIC WIND
SPEED0
;
70
75
75
ii
80
75
1
E
ii
90
State of MASSACHUSETTS
BARNSTABLE
BERKSHIRE
BRISTOL
DUKES
ESSEX
COUNTY
16
iik?iiiY
GRANDTMvERsE
G&SHOT
HJLLSDALE
HOUGHTON
HURON
INGHAM
IONIA
IOSCO
IRON
ISABELLA
JACKSON
-00
1
1
1
1
1
ii
75
75
75
75
75
70
80
KEWEENAW
LAPEER
LEIZANAU
LENAWEE
LIVINGSTON
LUCE
MACKINAC
MACOMB
iizgEIE
MASON
MECOSTA
MENOMINE
MIDLAND
MISSAUKEE
MONROE
MONT.CALM
MONTMORENCY
MUSKEGON
NEWAYGO
OAKLAND
E
75
75
75
70
75
75
75
1
1
1
1
ii
75
75
70
75
75
80
80
80
ii
75
75
75
75
75
80
80
75
’
TIA/EIA-222-F
Stateof MXCHlGAN
COuNrY
NOTE*
OCEANA
OGEMAW
ONTONAGON
OSCEOA
OSCODA
OTSEGO
OTTAWA
PRESQUEISLE
ROSCOMMON
SAGINAW
SAINTCLUR
SAINT JOSEPH
SANTLAC
SCHOOL CEuFr
SHIAWASSEE
TUSCOLA
VANBUREN
WMH’IENAW
WAYT+JE
WEXFORD
State dMINNESOTA
BASIC WIND
spEED(MpH)
1
80
75
75
75
1
;
80
75
75
1
1
1
1
;
1
1
z
80
1
1
E
.
EE
JACKSON
KANABEC
IMNDIYOBI
KrITSON
KOOCHKHING
LACQUIPiUUE
iFI
ii
75
75
80
85
85
LAKE OF TEE WOODS
LE!mErJR
LINCOLN
LYON
MAHNOMEN
MARS=
8”o
80
MCLEOD
ANOKA
ii
85
80
80
90
80
80
*For notes, see end
85
80
80
75
80
80
ii
80
80
80
85
80
ii
BECKER
BELXRAMI
BENTON
BIG STONE
BLUEEARTH
BROWN
CARLXON
CARVER
ERWMER
COOK
COTIONWOOD
CROWWING
DAKOTA
DODGE
DOUGLAS
FARIBAUEI’
FILUAORE
FREEBORN
GOODHUE
HOUSTON
-ARD
iz
Statedm0~~
iii%kWA
CHISAGO
BASIC WIND
NOTE* SPEs>(MpH)
COUNIY
1
MlLLELAcs
MORRISON
MOWER
MURRAY
NIcouEr
NO&ES
NORMAN
OLMSIED
OTIERTAIL
PENNINGION
:z
80
ii:
ii:
85
85
80
80
85
80
80
PIPESTONE
POLK
ii
iz
75
90
80
70
85
i:
80
85
80
EEEY
REDLAKE
REDWOOD
RICE
ROCK
ROSEAU
sAlNTLouIs
SCOIT
SHERBURNE
SIBLEY
ii
80
ii
ii
.?i-zz?
SEVENS
ii
80
TODD
TIMERSE
of Section 16
Yz
1
iti
85
E
.
state ufMx!sIssIPP1
State of h4lNNESOTA
COUNTY
NOTE*
BASIC WIND
SPEEDWH)
WABASHA
WmENA
WASECA
WASBINGTON
wmoNwAN
80
80
80
ii:
EE4
WRIGHT
YELL0wh4ED1cINE
ii
80
85
state of MISSISSIPPI
ADAMS
ALCORN
80
2
KITilLA
BENTON
BOLTVAR
CALHOUN
CARROLL
CBICKASAW
CHO(JTAW
CIAIE3ORNE
ii
zi
70
;i
70
70
75
2
CLAY
coAHoMA
COPIAH
COVINGTON
DE SOT0
FORREST
GEORGE
GRENADA
HANCOCK
HARRISON
HINDS
HOLMES
HUMPHREYS
ISSAQUENA
lTAWAMBA
JAQCSON
JASPER
JEFFERSON
JEFFERSONDAVIS
JONES
2
2
2
2
2
2
2
2
2
2
LAFAYEITE
2
LAuDEflDALE
*For notes,seeend of Section 16
$
70
80
80
70
90
85
ii
70
100
100
75
70
70
70
70
100
75
80
85
85
70
70
90
75
COUNTY
NOTE*
2
E&E
IJNCOLN
LOWNDES
MADISON
MARION
MARSHALL
MONROE
MONTGOMERY
NESHOBA
NEWTON
NOXCJBEE
OKTIEBEHA
PANOLA
PEARLRIvER
PERRY
2
2
2
2
2
EOTOC
PRENTISS
QscolT
SHARKEY
SIMPSON
SMIIH
STONE
SUIWXOWER
TALLxmTcHlE
Tm
TIePAH
TISHOMINGO
TUN-ICA
UNION
WAJXHALL
WARREN
WASHINGION
WAYNE
CN
WINSTON
YALOBUSHA
wzoo
2
2
2
2
BASIC WIND
SPEED0
85
70
70
70
85
70
z
70
70
70
70
75
70
70
70
ii
90
70
70
70
75
75
70
80
75
95
70
70
70
70
70
70
70
90
70
70
85
70
90
70
70
70
stalebofMIssouRI
state of MISSOURI
COUNTY
NOTE*
BASIC WIND
SPEEDtMnD
AT'CBISON
AUDRAIN
BARRY
BARTON
BAIES
BENTON
BOLLlNGER
BOONE
BUCHANAN
BUTLER
CALDm
CALLAWAY
CAMDEN
CAPEGIRARDEAU
CARROLL
CLAY
cLINKIN
COLE
COOPER
CRAWFORD
DADE
DALI&
DAVIEZS
DEKALB
DENT
DOUGLAS
DUNKLIN
GRUNDY
HARRISON
HENRY
HICKORY
HOIX
HOWARD
HOWELL
*For notes, see end of Section
3
LINCOLN
16
E%s-I~N
MACON
MADISON
R
ESJ
MCDONALD
MERCER
ii:
MISSISSIPPI
MONIlEAU
MONROE
MONTGOMERY
MORGAN
NEWMADRID
NEWTON
NODAWAY
OREGON
OSAGE
OZARK
PEMISCOT
70
70
70
70
70
80
70
75
80
70
70
80
70
70
EiitE!%E
GENTRY
a
ZON
JOHNSON
KNOX
LACLEDE
L/WALAWRENCE
70
75
70
75
75
80
70
70
70
70
70
ZON
IRON
JACKSON
75
80
80
70
70
70
70
70
70
70
75
70
70
70
75
CASS
COuNlY
EiEi
PHELPS
POLK
PUTNAM
luNDoLPH
RAY
REYNOLDS
NOTE*
BASIC WIND
SPEED0
70
75
70
70
75
75
70
E
ii
75
75
75
70
70
70
70
80
70
70
70
70
70
70
70
70
80
70
70
70
70
70
70
70
iii
70
70
75
70
70
75
70
70
1 Irv Cl&-&-t
state
COUNTY
StatedMONTANA
ofMIssouRI
NOTE*
BASIC WIND
SPEED0
SAINTCHARLES
SAINTCLUR
sAINTFRANcoIs
SAINTGENEVEW
70
70
70
70
70
70
75
75
75
70
70
75
70
70
75
SAINT LOUIS
SAINTLOUIS CrIY
SAWBE
3z
Sal-T
SHANNON
SBELBY
STODDAEtD
iEz!kJ
ii
EE
VERNON
WlRREN
WASHINGTON
WAYNE
.-=
WORTH
WRIGHr
70
70
70
zi
80
70
StateofMONTANA
BEAVERBEAD
BIG HORN
BLAINE
BROADWm
CARBON
EEEiE
cHouIEAu
CUSTER
I
1
DAWSON
DEERLODGE
FAILON
FERGUS
EiiEE?
GOLDENVALLEY
ii
75
80
80
75
DANIELS
GAIJAIN
70
1
1
1
*For notes,seeend of Section 16
ii
80
80
70
80
80
70
iii
2
75
80
COUNIY
NOTE*
70
80
70
75
80
JEFFERSON
JUDII-HBASIN
.
ELNDCLARK
LJBEKE
LINCOLN
MADISON
MCCONE
MEAGHER
iiiiEE4
MusPARK
PEIROLEUM
PHIlUPS
PoNDEm
POWDERRIVER
KwELL
RAVALU
RICBLAND
ROOSEVEU
ROSEBUD
ii
80
75
70
70
85
80
ii
1
;z
1
1
ziiE!Ek
SILVERBOW
SITEWAIER
SWEIXGRASS
WON
Tool-E
TREASURE
BASIC m
SPED(MpM
‘1
1
gggm,
WIBAUX
YELLOWSTONE
70
80
70
80
80
85
70
80
70
80
80
75
75
85
80
80
ii
state of NEBRASKA
BANNER
BIdUNE
BOONE
BOXBU’ITE
BOYD
BROWN
BUFFALO
:
85
85
85
i;
85
T.wEIA-222-F
StateofNEBRASIcA
COUNTY
NOTE*
StatelTfNEWUSKA
BASICWIND
spEED0vfPH-l
BURT
BUTLER
CASS
CEDAR
CHASE
EiEFzkE
CLAY
coIx4x
EKE?
DAKOTA
DAWES
DAWSON
DEUEL
DIXON
DODGE
DOUGLAS
DUNDY
FILLMORE
FRONTER
FURNAS
GAGE
GARDEN
GARFIELD
GOSPER
80
80
80
85
85
80
85
ii
E
85
85
ii
80
ii
85
iz
80
85
85
85
85
ii;
ii%i~T0~
KEYA PAHA
KlMBALL
KNOX
LANCASTER
LINCOLN
LOGAN
LOUP
MADISON
*For notes, see end of Section 16
NOTE*
MCPBERSON
MERRICK
MORRILL
NANCE
:
85
ii
5
80
80
85
85
85
85
80
85
80
NUCKOIU
OTOE
PAWNEE
PBELPS
PERCE
POLK
REDwILulW
RICHARDSON
ROCK
SALINE
SARPY
SAUNDERS
SCOITS BLUFF
ii
80
80
85
ii:
85
iikz%zN
SHERMAN
SIOUX
SlApON
THAYER
THOMAS
THURSTON
VAlXZY
WASHING’TON
WAYNE
wEB!nER
iz
80
g
85
80
85
85
85
80
YORK
ii:
85
85
80
%teofNEVADA
CHURCHILL
ii
85
85
85
ifI
85
85
85
85
BASIC WIND
SPEED(MpH)
ii
ii
GREELEY
HAYES
HITCHCOCK
HOIX
HOOKER
HOWARD
EFFER!SON
JOHNSON
COUNTY
DOUGLAS
ELXO
ESMERALDA
HUMBOLDT
.LANDER
IJNCOLN
LYON
75
1
1
;i
70
75
80
70
80
80
70
'.
stateofNEwh4ExIco
Stare c&NEVADA
COUNTY
NOTE*
BASIC WIND
sPEED(Mpm
1
SlmEY
WASHOE
WBIIEPINE
1
1
70
70
70
75
s~of~HAMPsHlR.E
BEIXNAP
CARROLL
CHESHIRE
coos
-ON
HILLSBOROUGH
MERRIMACK
ROCKINGHAM
sTRAFFoRD
SULLIVAN
2
2
2
12
12
2
2
2
2
12
80
80
;
70
::
85
85
75
state of NEW JEEtsEY
fXIUNTIC
BERGEN
BURLINGTON
EEilY
CUMBERLAND
ESSEX
GLOUCESTER
HUDSON
HUNTERDON
MERCER
MIDDLESEX
MONMOUTH
MORRIS
OCEAN
PASSAIC
SALEM
SOrvlEluEr
SUSSEX
UNION
WARREN
*For notes, see end
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
of Section 16
85
80
80
80
85
80
80
f ii
75
80
80
85
75
ifi
80
80
70
80
70
NOTE*
COUNTY
BASIC WIND
SF’EED(MpH)
70
BERNALILLO
CKtRON
cHAvl3
UBOLA
COLFM
CURRY
DEBACA
DONAANA
EDDY
ii
70
80
80
80
70
75
70
tiEE!iLuPE
HARDING
HIDALGO
1
LmcoLN
Los ALAMOS
LUNA
MCKINLEY
MORA
OIERO
QUAY
RIO ARRIBA
ROOSEVETX
SANDOVAL
SANJUAN
SANMJGUEL
SANTAFE
SlEEUZA
SOCORRO
TAOS
TORRANCE
UNION
VALENCIA
1
ii
1
1
1
1
ii
75
;i
70
80
70
80
75
80
70
70
80
75
70
70
80
75
85
70
stateofNEwY0R.K
ALBANY
AILEGANY
BRONX
BROOME
~ARAUGUS
CAYUGA
CHAUTAUQUA
CBEMUNG
CHENANGO
CLINTON
COLUMBIA
CORTLAND
70
2
1
12
ix
70
70
70
70
70
70
70
70
70
stareofNEwYoRK
COUNTY
NOTE*
DELAWARE
DUTCBESS
State c&NORTH CAROIJNA
BASIC WIND
SPEEoMPm
12
1
ESSEX
12
70
70
70
70
;
HAMILTON
;:
iiiEi%J
KINGS
LIVINGSTON
MADISON
MONROE
MONTGOMERY
NASSAU
NEW YORK
NIAGARA
ONEIDA
ONONDAGA
ONTiwO
ORANGE
ORLEANS
0swEGo
OTSEGO
F$ziir
RENSSELAER
RICHMOND
ROCKLAND
SAINTLAWRENCE
SARATOGA
ScBENEcI=ADY
scHoHARIE
SCHUYLER
SENECA
STEUBEN
SUFFOLK
SULLIVAN
TIOGA
TOMPKINS
2
2
2
1
12
2
2
2
2
2
2
1.2
kifizzk
WASHMZTON
WAYNE
WESTCHESTER
WYOMING
Ym
2
*For notes, see end of Section 16
ii
70
70
70
70
70
85
80
70
70
70
70
70
70
70
70
ii:
70
85
80
70
70
70
70
70
70
70
85
70
70
70
70
70
70
70
80
70
70
COUNTY
NOTE*
1
ANSON
1
1
2
2
AVERY
BEAUFOIU
BEKllE
BLADEN
BRUNSWICK
BUNCOMBE
BURKE
CABARRUS
CALDWELL
CAMDEN
2"
1
2
.2
EitfEsF
CMAWBA
CHEROKEE
CHOWS
Ei%LAND
COLUMBUS
cm..
CUMBERLAND
CURRIIUCK
DARE
DAVIDSON
DAvlE
DUPLIN
DURHAM
BDGECOMBE
FORSYTH
2
2
2
2
2
2
2
2
2
GASTON
9
1
L
iiiE?iM
2
iiisziw
2
iizis%
HAYWOOD
HENDERSON
HEEZTFORD
HOKE
HYDE
IREDELL
JACKSON
1
2
:
1
BASIC WIND
-(MPH)
70
70
70
75
70
70
100
ii
loo
70
70
70
70
100
110
70
70
70
70
95
70
70
95
loo
80
loo
110
70
70
95
75
80
70
75
70
90
70
70
85
70
80
75
70
70
85
75
110
70
70
State ofNORTH CAROLINA
COUNTY
NOTE*
BASIC WIND
SPEED0
JOHNSTON
JONES
2
2
80
100
LENOIR
LINCOLN
MACON
MADISON
2
iii
70
70
70
90
70
70
70
70
MCDOWELL
MECKLENBURG
MrrcHELL
MONTGOMERY
MOORE
NASH
NEwHANovER
NORTHAMPTON
ONSLOW
ORANGE
PAMLICO
PAsQUOTANK
PENDER
PERQUIMANS
PERSON
PlTT
POLK
RAM>OLPH
RICHMOND
ROBESON
ROCKINGHAM
ROWAN
RUTHEXFORD
SAMPSON
SCOTLAND
STANLY
STOKES
suRRY
SWAIN
TFaNsYLvANIA
1
1
2
1
2
2
2
2
2
2
f
2
2
2
2
1
2
UNION
VANCE
WAKE
WARREN
WASBINGTON
WMAUGA
WAYNE
WIUON
YADIUN
YANCEY
2
2
2
1
2
2
1
*For notes, see end of Section 16
lli
105
80
100
70
105
95
100
95
70
90
70
70
75
80
70
70
70
85
80
70
70
70
70
70
loo
70
75
75
75
100
70
85
70
80
70
70
State of NORTH DAKOTA
I
COUNTY
ADAMS
BARNES
BENSON
BIKJNGS
BOTTTNEAU
BOWMAN
BURKE
BURLEIGH
CASS
CAVAWER
DID
DIVIDE
DUNN
EDDY
EMMONS
FOSTER
GOLDENVALLEY
GRAND FORKS
EiZ
BEITINGER
KIDDER
LAMOURE
LOGAN
MCBENRY
MCINTOSH
MCKENZIE
MCLEAN
MERCER
MORTON
MOUNTRAlL
NELSON
OLIVER
PEMBINA
PIERCE
RAMSEY
RANSOM
NOTE*
-.
BASICWIND
SPEED0
80
ii
80
ii
ifi
85
75
85
;
80
80
80
ii
75
80
80
80
80
80
75
80
80
75
75
75
75
80
75
80
75
EiE
STUTSMAN
TOWNER
ii
75
90
75
90
75
80
80
80
80
80
75
WALSH
II;
RICHLAND
ROLEI-IE
SARGENT
SHERIDAN
SIOUX
SLOPE
Stateo.f0BI0
State of NORTHDAKOTA
COUNIY
NOTE*
BASIC WIND
-0MpH)
COUNTY
state OfoBJo
ADAMS
ASHLAND
ASHTABULA
Al-HENS
AUGLAQE
BELMONT
BROWN
70
75
70
70
70
70
70
70
70
70
70
1
EEL
CHAMPAIGN
EEEONT
CLINTON
COLUMBIANA
COSHOaON
cluwFoRD
CUYAHOGA
DARKE
DEFiANCE
DELAWARE
;:
70
70
70
70
70
70
75
70
70
70
70
70
75
70
70
70
70
70
75
70
70
75
70
70
70
70
70
70
70
1
1
FAIRFIELD
FAYEiTE
FiJITON
GALLIA
QAUGA
1
Es&Y
HAMILTON
HANCOCK
%%!3N
HENRY
HIGHLAND
HOCKING
HOLMES
BURON
JACKSON
JEFFERSON
KNOX
1
*For notes, see end of Section
16
BASIC WIND
SPEED0
1
75
EtEi
WILLIAMS
NOTE*
LICKING
LOGAN
limAIN
LUCAS
MADISON
MAHONING
MARION
MEDINA
MEIGS
IbEEKER
MONROE
MONTGOMISY
MORGAN
MORROW
MusKINGuM
NOBLE
O’ITAWA
PAULDING
PERRY
PImWAY
POWAGE
PREBLE
PUTNAM
RIROSS
SANDUSKY
sclom
SENECA
SHELBY
STARK
TRUMBULL
TUSCARAWAS
UNION
VANWERT
VINTON
WARREN
WASHINGTON
WAYNE
WOOD
WYANDOT
1
;
70
70
70
75
70
70
70
70
70
70
70
70
70
70
70
70
70
75
75
70
70
70
70
70
75
70
70
75
70
70
70
70
70
70
70
70
75
70
70
70
70
75
75
70
[ IA/ tln-A,A-r
stateofoKLAHoMA
state of OKLAHOMA
COIJNTY
NOTE*
BASIC WIND
~(MPH)
ADAJR
ALFALFA
ATOKA
BEAKR
BECKHAM
EE
CADDO
CANADIAN
tiiEE&E
CHOClYAW
CIMARRON
COAL
COMANCHE
COT’IDN
z
CUSTER
DELAWARE
DEWEY
70
80
70
85
80
80
ii
80
70
70
70
85
75
70
80
80
70
70
80
IEFLORE
LINCOLN
LOGAN
LOVE
MAJOR
MARSHALL
MAYES
MCUAIN
MXUEEAIN
MCINTOSH
;!I
80
80
70
75
80
80
80
80
70
70
80
75
70
75
80
80
70
70
75
75
70
80
70
70
75
70
70
*For notes. see end of Section
16
GARFED
GARVIN
GRADY
HARMON
HARPER
HASKELL
HUGHES
JACKSON
JEFFEXON
JOHNSTON
KAY
KINGFISHER
KIOWA
NO-E*
COUNTY
BASIC WIND
SPEEDWH)
70
70
75
70
70
MURRAY
MUSKOGEE
NOBLE
NOWHA
0KFusKEE
OKMHOMA
OKMULGEE
OSAGE
OlTI’AWA
PAWNEE
PAYNE
PIITSBURG
FONTOTOC
POnAWp;ToMIE
PUSBMATAHA
ROGER h4IUS
ROGERS
SEMINOLE
SEQUOYM
!TIEPBENS
;
75
70
75
75
70
70
70
70
80
70
70
70
iiz
80
70
70
iFi?LN
TULSA
WAGONER
WASHINGlON
WA’SHITA
WOODS
WOODWARD
ii
80
80
State of OREGON
BAKER
BENTON
CLACKAMAS
CLATSOP
COLUMBIA
coos
CROOK
CURRY
DESCHUIES
DOUGLAS
GILLIAM
HOOD RIVER
JACKSON
JEFFERSON
JOS=
1
1
70
80
80
95
80
80
70
85
70
80
70
70
70
80
80
70
80
1ltL l2A-d”- t
state dPENNsYLvm
State of OREGON
COUNTY
NOTE*
BASIC WIND
SPEEDCMP~
1
1
1
75
70
80
90
80
1
1
iii
70
80
80
LINCOLN
MARION
MORROW
MULTN0MA.H
POLK
SHEEMAN
‘I’LLAMOOK
UMATILLA
UN-ION
WAUOWA
WASCO
WASHINGTON
1
1
1
COUNTY
FOREST
l%lNKLm
flEz!i
HUNTINmN
INDIANA
JEFFERSON
=A
LXKAWANNA
LANCASTER
LAWRENCE
LEBANON
ii!
70
70
70
70
80
70
80
NOTE*
2
2
2
2
EEEE
LYCOMING
MCKEAN
MERCER
MONROE
MONTGOhIEEtY
2
2
MONTOUR
State!0fPENNSYLVAMA
*
ADAMS
ALLEGHENY
ARMSTRONG
BEAVER
BEDFORD
BERKS
BLAIR
BRADFORD
BUCKS
BUILER
CAMBRIA
CAMERON
CARBON
CHESTER
CLARION
a
2
2
2
2
2
CLINTON
COLUMBIA
CRAWFORD
CUMBERLAND
DAUPHtN
DELAWARE
FAYEI-IE
*For notes, see end
of Section 16
70
70
70
70
70
70
70
70
75
70
70
70
70
70
75
70
70
70
70
70
70
70
75
70
70
70
NO-N
NORI'HUMBPERRY
PBILADELPIHA
POTIER
SSNYDER
SOMERsEr
SULLIVAN
SUSQUEEiANNA
TIOGA
UNION
VENANGO
WARREN
WASI3IN~N
WAYNE
WESTMOW
WYOMING
YORK
2
2
2
2
2
2
2
BASIC WIND
SPEED0
70
70
70
70
70
70
70
70
70
70
70
70
70
70.
70
70
70
70
70
75
70
70
70
70
75
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
State of RHODE ISLAND
.
BRISTOL
NEWPORT
PROVIDENCE
WASHINGTON
2
2
2
2
2
90
90
90
90
90
L
. .
“-12
‘
---,
State of SOUTH DAKOTA
State of SOUTH CAROLINA
COUNTY
NOTE*
BASIC WIND
SPEEDOLIPH)
ABBEVILLE
AmENDALE
ANDERSON
BAMEERG
BARNWELL
BEAUFORT
BERKELEY
CALHOUN
CHARLESTON
CHEROKEE
=zzLErD
(3LARENDON
COILEIDN
DARLINGTON
DILLON
DORCHESTER
EDGEFIELD
FAIRFlELD
FLORENCE
GEORGErOWN
=EiEii
HAMPION
HORRY
JASPER
KERSHAW
LwcAslER
LWRENS
75
2
ii
75
80
80
100
100
80
105
70
75
75
85
95
2
2
2
2
2
2
2
2
2
2
2
2
ii:
95
75
2
2
ifi
no
70
2
2
2
ii
100
95
75
75
75
80
75
85
80
75
75
70
80
70
75
75
70
80
75
90
70
2
EXINGTON
MARION
MARLBORO
MCCORMICK
NEWBERRY
OCONEE
ORM’EEEIURG
PICKENS
RKHLAND
SALUDA
%“ANBURG
SUMIER
UNION
WELIMSBURG
YORK
2
2
2
2
*For notes, see end of Section
16
NOTE*
COUNTY
AURORA
BEtiDLE
BENNEIT
BONHOMME
BROOJUNGS
BROWN
BRULE
BUFFALO
BUITE
CAMPBELL
CZARLESMIX
CLAY
CODINmN
CCIRSON
CUSTER
DAVISON
DAY
DEUELI
DEWEY
DOUGLAS
EOMUNDS
FALLRIVER
FAUIK
GREGORY
WON
HANSON
HARDING
HUGHES
HUTCHINSON
HYDE
JACKSON
JERAuJa
JONES
KINGSBURY
LAWRENCE
mcom
LYMAN
MARSHALL
MCCOOK
M-ON
BASIC WIND
SPEEDW~
.
80
ii
E
85
ii
ii
85
90
80
80
85
90
90
ii
ii
85
90
85
80
90
:
80
80
85
85
80
85
80
90
85
80
ii
90
85
80
80
80
85
85
State of SOUTH DAKOTA
COUNTY
NOTE*
BASIC WIND
sPEED(Mpm
MOODY
PENNINGTON
PERKINS
POTIER
ROBERTS
SANBORN
SHANNON
COUNTY
NOTE*
85
ii
ii
85
80
EtELY
SUUY
TODD
ifi
80
zizzl32
UNION
WALWORIH
YANK’IDN
ZlEE3ACH
ii
85
85
80
85
80
GRUNDY
HAMBLEN
HAMRXON
HANCOCK
HARDEMAN
HARDIN
HAWKINS
HAYWOOD
HENDERSON
HENRY
BICEMAN
HOUSTON
HWPHREYS
JA(xsON
JEFFERSON
JOBNSON
KNOX
1
1
state of TENNESSEE
ANDERSON
BEDFORD
BENIDN
BLEDSOE
BLOUNT
BRADLEY
CAMPBELL
CANNON
CARROLL
EiiEiAM
CLAIBORNE
E&
COFFEE
CROCKEIT
CUMBERLAND
DAVIDSON
DECQUR
DEKALB
DICKSON
DYER
FAYEITE
FENIRIS
GIBSON
*For notes, see end of Section 16
BASIC WIND
SPEEDWH)
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
LAUDERDALE
LAWRENCE
LINCOLN
LOtJ’DON
MACON
MADISON
MARJON
MARSHALL
MAURY
MChtlNN
MCNAIRY
MEIGS
MONROE
MONTGOMERY
MOORE
MORGAN
OBION
OVEFCON
PERRY
PICKEIT
POLK
PUTNAM
ROANE
ROBERTSON
RUlHERFORD
SCOTT
SEQUATCHIE
1
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
I lA/
IzlA-‘---‘r
state of TENNESSEE
COUNTY
NOTE*
1
SSE
sm
STEWART
SULLIVAN
SUMBIER
TIPTON
TROUSDALE
UNICOI
UNION
VANBUREN
WARREN
WASHINGTON
WAYNE
BASIC WIND
SpEEDoAm
corn
70
70
70
70
70
2
2
2
2
2
2
*For notes. seeend of Section 16
70
80
70
95
80
85
75
80
80
70
70
80
85
70
75
70
80
70
70
100
70
75
80
85
70
70
70
it
70
85
70
80
95
EiEERs
-0KEE
CHILDRESS
ii
75
80
80
75
EGERAN
EzzimN
COLIJN
COILINGSWORZIH
COLORADO
COMAL
’
COMANCBE
CONCH0
COOKE
CORYELL
co-mx
.
z
CROSBY
CULBERSON
DALLAM
DALLAS
DAWSON
DEWIIT
DEAFSMlTH
DELTA
DlENToN
DICKENS
DIMMIT
DoNmY
DW&
EASTLAND
ECTOR
mwARDs
ELPMO
EEI
FMJS
FANNIN
FAYETTE
FISHER
BASICWIND
SPEED(MPR)
if
ZN
CASS
state of TEXAS
ANDERSON
ANDREWS
ANGELINA
ARANSAS
ARCHER
ARMSTRONG
M’ASCOSA
AUSTIN
BAILEY
BANDER4
BASTROP
BAYLOR
BEE
BELL
BEXAR
BLANC’0
BORDEN
BOSQUE
BOWIE
BRAZORIA
BRAZOS
BREWSTER
BRI!XOE
BROOKS
BROWN
BURLESON
BURNET
NOTE*
i!izEF
iiIzEF
;:
70
70
70
70
70
70
70
70
70
70
70
SSON
WILSON
StateOfTEXAS
I
2
2
ii
80
70
70
75
70
70
80
80
75
80
75
8s
70
80
80
80
70
70
80
75
ii
75
80
75
70
70
70
70
70
75
80
.
S~ofTExAS
COuNlY
FLOYD
FOARD
FORTBEND
NOTE*
zii%Eks
GRAY
GRAYSON
izzz
GUADALUPE
BASIC WIND
-0
COUNTY
NOTE*
2
2
2
2
2
HAMILTON
HANSFORD
HARDEMAN
HARDIN
HOCKLEY
HOOD
HOPKINS
HOUSTON
HOWARD
HUDSPEI-H
HUTCBINSON
IRION
JA(x
JACKSON
JASPER
JEFFDAVIS
-ON
JIM HOGG
JIMWELLS
JOHNSON
*For notes. see end of Section 16
KAUFMAN
KENDALL
KENEDY
ifi
ml
80
70
80
85
75
80
70
70
75
HARRBON
i.iEiE
HAYS
HEMPBILL
HENDERSON
HIDALGO
2
:i
90
70
70
it
80
70
85
80
90
90
iii
80
ii
70
80
70
80
70
70
70
80
70
70
85
75
75
90
80
75
100
80
80
70
BASIC WIND
SEarIm
80
JONES
FREESTONE
FRIO
*EELON
GARZA
GILLESPIE
GLAsscocK
StateClflEXAS
2
KIMBIX
KlNG
KLEBERG
KNOX
IASALLE
i?EF
LAMFASAS
LAVACA
.
Ei
70
90
EON
LTBERIY
IJMESTONE
LIPSCOMB
LJVEOAK
LLANO
LOVING
LUQBOCK
LYNN
MADISON
MARION
z
80
70
75
iFi
70
ii
70
95
MASON
MKAGORDA
MAYERIcK
MCCULLOCH
MCLENNAN
MCMUILEN
MEDINA
MENARD
MIDLAm
MILLS
MlTcHELL
MONTAGUE
MONTGOMERY
MOORE
MORRIS
MOTEY
NACOGDOCHEZ
NAVARRO
NEWTON
;:
70
95
80
70
75
80
75
90
80
75
70
80
70
2
2
E
70
80
75
75
80
70
70
80
70
85
85
ii:
70
70
85
.
- - ---
- ----I
StateOf-XEXAS
stare OfTExAs
COUNTY
NOTE*
BASIC WIND
=Em(MpH)
NOLAN
ii
85
85
95
70
iiEEiEE
OLDHAM
ORANGE
R4LoPlNTO
PANOLA
;:
80
iitEi!z
PECOS
POLK
ii
85
75
70
ilEE
EEIIL
REAGAN
ii
75
70
EiTkvER
iEE0
ROBERTS
ROBERTSON
ROCKWAu
RUNNELS
RUSK
SABINE
SANAUGUSTINE
SAN JAQNTO
SANPmuao
SANSABA
SCHLEICBER
SCURRY
SHAaELFORD
SHELBY
SHERMAN
SMIIH
soMERvELL
STARR
STEPHENS
sTERLlNG
STONEWALL
SUITON
SWISHER
TARRANT
TAYLOR
2
2
2
z
80
70
70
75
70
75
75
80
;:
75
80
80
70
85
70
2
THROCKMORTON
TTIUS
*For notes. seeend of Section 16
;:
75
;o"
75
85
70
80
75
80
80
70
NOTE”
TOMGREEN
IRAVIS
ii
2
2
EfF
BASIC WIND
SPEmRvzpH)
iiEi!F
WALDE
v.VERDE
v.ZANDT
VImRIA
WALllEE!
WALER
WARD
WmGKlN
70
80
70
ii
$
90
75
ii
tZL3N
WICHCI-A
WILBARGER
2
XON
WILSON
2
WOOD
YaAKuM
YOUNG
ZAPm
ZAVALA
a
90
80
80
80
95
70
75
80
70
70
80
75
75
75
state of UTAH
BEAVER
BOXELDER
CACEIE
CARBON
DAGGEIT
DAVIS
DUCHESNE
EMERY
GARFIELD
IRON
iif&
MORGAN
70
70
70
70
75
70
70
70
70
70
75
70
70
70
70
70
state of UTAH
COUNTY
NOTE*
RICH
SALTLAKE
SANJUAN
SINPETE
BASIC WIND
sP=D(Mp)I)
75
70
70
70
70
70
EErr
TOOELE
UINTM
UTAH
WASAKH
WASHlNGTON
WAYNE
WEBER
;i
70
70
75
70
70
state of VERMONT
ADDISON
BENNINGIQN
CALEDONIA
-EN
ESSEX
GIUNDISLE
LAMOILLE
ORANGE
ORLEANS
RUILAND
WASHINGTON
WINDHAM
WINDSOR
70
1
1
1
1
1
:2”
;i
70
70
70
70
70
70
70
70
70
70
70
Stateof VIRGIN-IA
ACCOMACK
ALBEMARLE
ALLEGHANY
AMIIERST
APPomox
ARLlNGlTlN
AUGUSTA
B4Xl-H
BEDFORD
BLAND
BOTETOURT
BRUNSWICK
BUCHANAN
COUNIY
NOTE*
2
1
2
2
1
2
*For notes. seeend of Section 16
95
70
70
70
70
70
70
70
70
70
70
70
75
70
2
:
i
1
2
2
EELER
CUMBERLAND
DIQUZNSON
DINWIDDIE
ESSEX
FAIRE!
FAUQUIER
FLOYD
EWANNA
2
2
2
2
1
2
iiiiEi%
2
iZEkTER
GOOCHLAND
GRAYSON
:
2
1
2
2
iiiE%AE
HALIFAX
HANOVER
HENRICO
HENRY
HIGHLAND
ISLEOFWIGHI’
JAMESCITY
KlNGANDQUEEh
KINGGEORGE
KINGWILLIAM
LANCASTER
EEDOUN
LOUISA
LUNENBURG
MADISON
MIWIEWS
MECKLENBURG
MJDDLESEX
MONTGOMERY
NELSON
NEWKENT
NO-N
:
2
2
2
2
2
2
2
2
2
2
2
1
2
2
BASIC WIND
sPEEDt-h@m
70
70
75
70
80
70
z
70
70
70
70
ii
z
70
70
70
$
80
70
70
70
80
70
75
75
70
70
85
80
80
75
75
80
70
70
70
70
70
85
2
70
70
80
95
* *fi
&An-----,
State afWASHINGTON
State of VIRGINIA
COUNTY
NOTE*
2
NOKI’HLMBW
ORANGE
NOTTOWAY
PAGE
PmCK
mTTsYLvANL4
PowHmAN
PRINCEEDWARD
PRINCEGEORGE
PRrNcEwILuAM
PULASKI
mPPAHANNocK
RICHMOND
ROANaCE
ROCKBRIDGE
ROCKINGHAM
RUSSELL
SCOTr
SHENANDOAH
SMYTH
SO-N
SPOTSYLVANIA
STAFFORD
SURRY
SUSSEX
TAZEWELL
WARREN
WASHINGT’ON
WESTMORELAND
tz%E
YORK
BASIC WIND
SPEED0
80
2
:
70
70
2
;8
70
80
70
70
70
80
70
70
70
70
70
70
70
80
70
70
80
80
70
70
70
75
70
2
2
:
2
2
2
2
2
2
2
2
1
2
85
State of WASHINGTON
ADAMS
ASOTIN
BENTON
Ei!ztYm
z&n4
COwLnz
DOUGLAS
LizELm
1
1
1
GARFIELD
GRAYSHARBOR
1
*Fur notes. see end of Section 16
COUNTY
70
70
70
100
70
75
70
90
70
70
70
70
70
100
-ON
KING
KlTsAP
KmlTAs
IcLKKrrisr
NOTE*
1
1
1
1
1
LINCOLN
MASON
OKANOGAN
PACSFIC
PENDOREILLE
PIERCE
SANJUAN
SKAGIISNOHOMISH
SPOKANE
SEVENS
THCJRSTON
WAHKLXUM
WALLAWALLA
WHAKOM
BASIC WIND
SPEEDWH)
80
100
80
85
70
70
80
70
1
1
1
1
1
1
1
1
1
1
zi
100
70
80
80
70
70
75
70
70
80
100
70
70
70
70
State of WEST VIRGINIA
BARBOUR
BERKELEY
BOONE
BRAXTON
BROOKE
CABEU
CALHOUN
CLAY
DODDRIDGE
FAYEI-IE
GILMER
GREENBluER
HAMPSHIRE
HANco(x
HARDY
HARRISON
JACKSON
JEFFERSON
2
2
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
State ofWIScONSIN
StateofwESTvIRGl.~~
COUNTY
NOTE*
KANAWHA
70
70
LINCOLN
LOGAN
WON
MARSHAIL
MASON
MCDOWELL
ilttE?i
MING0
MONONGAIA
MONROE
MORGAN
NICHOLAS
OHIO
=NDEIZT’ON
PLEASANTS
POCAHONliU
PRESTON
PUINAM
RALEIGH
RANDOLPH
RlTcHIE
ROANE
SUMMERS
TAYLOR
TucKI
BASIC WIND
spEED(MpH)
1
1
UPSHUR
WAYNE
WEBSTER
WOOD
WYOMING
;:
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
70
NOTE*
COUNIY
CBIPPEWA
.
COLUMBIA
CRAWFO~
DANE
DODGE
ERu
4B
1
1
1
CALuMEr
*For notes. see end of Sea&m 16
90
75
80
75
90
75
80
90
ii
85
85
85
1
1
ii
LFFLORENCE
PONDDULAC
FOREST
1
iELA.IE
IOWA
IRON
JACKSON
-ON
1
JUNEAU
KENOSHA
KEWAUNEE
LA CROSSE
LAPALANGLADE
UNCOLN
MANITowoc
-ON
ii
ii
85
80
ii
iz
1
1
MARQUEITE
MENOMINEE
MILWAUKEE
MONROE
ocolvm
ONEIDA
OUTAGAMIE
OZAUKEE
PImcE
POLK
PORTAGE
PRICE
&mNE
RIROCK
RUSK
SAINT CROIX
ii
80
85
85
80
85
85
1
1
1
State of WISCONSIN
ADAMS
AsHrAND
BARRON
BAYFIELD
BROWN
BURNEIT
BUFFALO
BASIC WIND
SPEED=
1
ii
85
90
90
80
85
90
80
90
So
80
80
75
90
ii:
85
80
ii
StateofWYOMNG
State of WISCONSIN
COUNTY
SAUK
SAWYER
SHAWANO
SHEBOYGAN
TAYLOR
NOTE*
85
1
TREMPEALEAU
VERNON
WLWORTH
WASHBURN
WASHINGTON
WAUKE-SHA
WAUPACA
WAUSHAR4
WINNEBAGO
WOOD
BASIC WIND
spEED(Mpm
1
1
zl
85
80
80
85
ti
75
ii
90
90
90
90
BASIC WIND
COUNTY
ALBANY
BIG HORN
CAMPBELL
CARBON
t3mwRsE
CROOK
FREMONT
GOSHEN
HOT SPRINGS
JOHNSON
ImcoIJJ
NAlRONA
NIOBRARA
PARK
SHERIDAN
SuBLElTE
SwEErwAIER
TETON
iEzLKrE
WESTON
NOTE*
1
SPEEDcMm
90
i!iE
ii
80
85
85
ii!
*
85
75
1
1
1
1
1
E
80
90
85
80
80
75
75
85
80
.
References:
1. ASCE, ‘Minimum Design Loads for Buildings and Other Structures”, ASCE 7-88,
American society of Civil Engineers, New York, NY, 1988.
2. MBMA, “Low Rise Building Systems Manual”, Metal Building &tmfacturers Association,
Inc., Cleveland, Ohio, 1986.
3. UBC, “Unifmn Building Code”, International Conference of Building Officials, Whittier, CA
1988.
Notes:
1. Site may be within a special wind region indicated on AXE 7-88 wind map.Check with
local authorities before specifying basic wind speed.
2. County is within 100 miles from hurricane oceanline. Tabulated values of basic wind speed
have been adjusted in accordance with AXE 7-88 to obtain 50-year recurrence intervals.
3. For locations not designated as a county, use basic wind speed for the closest county to the site.
4. The wind speedslisted in Section 16 are fastest-mile wind speeds.3-secondgust speedssuch as
those contained in ASCE 7-95, and wind speeds averaged over other time periods, must be
converted to fastest-mile wind speeds for use with this standard. (Refer to Annex A, Section
7’77)
ANNEX A: PURCHASER CHECKLIST
ElM-IA-222
standards are intemkd to set minimum uitaia for the design, fabrication and
~o~~cth
of antenna supporting stnrctures. It is the responsibility of the purchaser to provide
Site-specific data and requirements differing from those contained in these standards. The following
checklist is intended to alert the purchaser to the most common areas where specific data may be
required.
Reference
Section
Purchaserchecklist
2.1.3
A. It is the responsibility of the purchaser to verify that the wind loads and design criteria
specified meet the rquirements of the local building code. If other loading criteria are
required, they shall be provided to the designer.
B. This standard is basedon an allowable stressdesign (ASD) method. Therefore, the use of
terms with an ambiguity in meaning and intent such as survival, shall withstand, etc. is
not appropriate.
C. Dividing the calculated wind pressure by a factor is considered inconsistent with this
standard. See 2.1.3.1 for the proper definition of basic wind speed.
2.3.1.2 A. It is the responsibility of the purchaser to specify appropriate ice loads for locations
where ice accumulation is known to occur.
B. The standard does not specify ice-loading requirements since ice accumulation may vary
subst~tially within a given geographical area.
C. It is recommended that a rn,hhm. l/2 in. C12.7 mm] of solid radial ice be specified for
locations where ice accumulation is known to occur.
2.3.3 A. For bidding purposes it is recommended that the purchaser specify the basic wind speed
(V) to obtain designs based on identical criteria. Wind speedsspecified for use with the
standard shall be fastest-mile wind speeds at 33 ft [lo m] above ground level.
B. The basic wind speed from Section 16, the equations for the exposure coefficient (Kz),
and the gust response factor (cH> are based on wind conditions in open, level country,
and grasslands.
C. The equations specified for Kz and G result in conswvative design wind loads for
thm and wooded areas.
D. It is the responsibility of the purchaser to specify basic wind speeds and appropriate
equations for Kz and @ in hurricane, mountainous, and coastal areas, in the special
wind regions indicated in Section 16 and where local conditions require special
consideration.
E. The purchaser shall identify the elevation of the base above average ground levei when
the structure will be placed on another structure or on a hill or escarpment.
F. The purchaser shall identify the relative elevations of the guy anchors with respect to the
structure base and shall identify the maximum and minimum permissible guy radii.
G. The basic wind speeds provided in Section 16 correspond to an annual probability of
0.02 (SO-year recurrence interval). If the purchaser requires another probability, the
basic wind speed shall be provided to the designer.
I‘IA/EIA-‘/‘-I-
2.3.16 A. Due to the low probability that an extreme ice load will occur simultaneously with an
cmeme wind load, wind load has been reduced 25 percent when considered to occur
smm.baneously with ice (quivaient to 87 percent of the basic wind speed).
B. For b&c wind speeds based on a 50-year recurrence interval (.02 annual probabi.Q),
the reduced wind load approximately corresponds to a 5-year recurrence interv~.
C. It is the responsibility of the purchaser to specify other critical wind and ice loading
combinations for locations where mote severe conditions are known to occur.
5.1.1
A. Galvanizing is the preferred method of providing corrosion control. Alternate methods
of cormion control, such BS epoxy
paint, chlorinated latex paint, plating,
elecuogdvanizing, etc., may be used only when specified by the purchaser.
B. The pudmer shall specify the requirements of additional corrosion control systems
when required. ( Refer to Annex J for corrosion control options for guy anchors in direct
contact with soil.)
7.2.2
A. When standard foundations and anchors are utilized for a final design, it is the
purchaser’s responsibility to verify by geotechnical investigation that actual site soil
parameters equal or exceed normal soil parameters. If the purchaser elects to accept the
normai soil foundation for construction, he accepts the responsibility and liability for the
adequacy of the subsurface soil conditions.
B. It is the responsibility of the purchaser to verify that the depths of standard foundations
are adequate based on the frost penetration and/or the zone of seasonal moisture
variation.
7.2.3.2 A. The geOteCh&al engineer shall be informed of the provisions of this section.
11.2
A. The purchaser shall specify the operational requirements when the minimum standard
does not apply.
12.2
A. The purchaser shall specify other grounding requirements for conditions where the
minimum standard will not be adequate.
13.2.1 A. The purchaser shall specify requirements for climbing and working facilities, hand or
_ -.
. ..
guardra% and climbing safety devices.
16
A. The purchaser is advised that the basic wind speeds listed in Section 16 are minimum
values. Specific sites may have local extreme wind conditions that are more severethan
the listed values. Topographical characteristics such as smooth terrain, bltis, ducting,
mountain top exposure, and prevailing wind directions can significantly increase wind
speeds. The purchaser is advised to consult local information sources such as the
National Weather Service (NWS), local weather agencies, owners of existing towers at
the same or nearby sites, local landowners, and consuking meteorologists.
TLVEIA-222-F
ANNEX B: DESIGN WIND LOAD ON TYPICAL MICROWAVE
ANT~NAS/RJ~FLECTOR~
This Annex COnkns data for calculating the design wind load on typical microwave amen&
reflectors.
Wind-loading values have been compiled from a wide variety of sources. Some data are
based on wind tunnel tests, and some are based on theoretical calculations. Precise antenna
geometry may vaty between manufacturers, who should be consulted for data concemiitg their
products.)
mote:
Wmd force data presented in this annex for parabolic antennas (iucluding grid antennas) are
described in the antenna axis system having the origin at the vertex of the reflector. The axial force
PA.) acts along the axis of the antenna. The side force (Fs) acts perpendicular to the antenna axis in
the phe of the antenna axis and the wind vector.
‘I’he twisting moment (M) acts in the plane
cOn*g
FA and Fs.. (See Figures B 1, B2, and B3.)
For horn antennas, the origin is at the intersection of the vertical antenna axis with a plane tangent to
the bottom of the boresight cylinder. The axial force FA acts parallel to the antenna boresight axis.
The side force (Fs) acts perpendicular to FA in the plane 0fF~ and the wind vector. The twisting
moment M acti in the plane containing FA and Fs. (See Figure B4.)
For flat plate passive reflectors, the origin is at the cemroid of the plate area. The axial force FA acts
along the normal to the plate. The side force (Fs) acts perpendicular to FA in the plane of FA and the
wind vector. The twisting moment M acts in the plane containing FA and Fs, (See Figure BS.)
In all c=es, the magnitudes of FA, Fs, and M depend on the dynamic pressure of the wind, the
projected frmal area of the antenna, and the aerodynami.c characteristics of the antenna body. The
aerodpdc
characteristics vary with wind angle. The values of FA, Fs, and M shall be cakukted
.
from the following equations:
FA = CA AKzGrrV2(lb)
Fs=Cs AKzeV2(1b)
M=CM
ADKz%V2(ft-lb)
Where: CA, Cs , and CM are the coefficients contained in Tables B 1 through B6 as a function of wind
angle 0.
Gl
A
= Gust response factor from 23.4
= Outside aperture area (sq ft) of parabolic reflector, grid, or horn antenna
5 Plate area (sq ft) of passive reflector
D
= Outside diameter (ft) of paraboloid reflector, grid, or horn antenna
= Width or length (ft) of passive reflector (see Figure B5)
V
= Basic wind speed (mph) fkrn 2.3.3
= Exposure coefficient from 2.3.3 with z equal to the height of the
Origin of the axis system
= Wind angle (deg); see Figures Bl through B5 for positive sign conventions
Kz
0
(Note: The coefficients described in Tables B 1 through B6 are presented in the customary system of
units. When SI units are desired, the results of the above equations may be converted using the
conversion factors provided in Annex G.)
Table BI. Wind Force Coefficients
WND ANGLE
Q (DEG)
0
10
20
30
40
50
60
70
80
for Typical Paraboloid Without Radome
c,,
CA
.00397
.00394
.003%
JO398
.OO408
.00426
AI0422
.00350
.00195
.ooooo
-.00012
-JO013
-.00008
.oooo2
.00023
.00062
.00117
.00097
.OOOOOO
-BOO065
-JO0097
-.000108
-.000137
-.000177
-JO0223
-.000020
JO0256
90
100
110
120
130
140
150
160
170
-.00003
-.00103
-.00118
-.00117
-.00120
-.00147
-.00198
-JO222
-.00242
.00088
.00098
.00106
.00117
.00120
JO114
.OOlOO
BOO75
BOO37
BOO336
BOO338
.000343
.000366
.000374
BOO338
JO0278
.000214
.000130
180
190
200
210
220
230
240
250
260
-.00270
-.00242
-.00222
-.00198
-.00147
-.00120
-.00117
-.00118
-.00103
.ooooo
-.00037
-BOO75
-.OOlOO
-.00114
-.00120
-.00117
-.00106
-BOO98
.oooooo
-.000130
-.0002 14
-.000278
-AI00338
-Al00374
-AI00366
-ho343
-BOO338
270
280
290
300
310
320
330
340
350
-.00003
.00195
.00350
xl0422
.00426
AI0408
JO398
.00396
AI0394
-.00088
-.00097
-.00117
-JO062
-BOO23
-.00002
JO008
.00013
.00012
-BOO336
-.000256
.000020
.000223
.000177
BOO137
.000108
.000097
.000065
Table B2. Wind Force Coefficients for Typical Paraboloid With Radome
a
WIND ANGLE
0 @EG)
CA
aoooo
.ooooO
-.ooo204
400285
0
10
20
30
40
50
60
70
80
.00221
.00220
.00210
.00195
.00170
.00140
.00107
.00080
JO058
.00038
JO076
DO105
SKI125
.OD136
.00128
.00118
.00112
-JO0277
-.Ooo205
-.ooo114
-.OoOOo2
.m130
.000268
90
100
110
120
130
140
150
160
170
AI0034
.00008
-.00017
-.00042
-.00075
-.00105
-.00133
-.oo 154
-.00168
.OOlCM
.OOlOO
JO095
.00089
.00082
.00078
.00070
.00058
.00038
.000390
.000434
.ooo422
.ooo4o4
.000357
JO0232
JO0132
AIOOO63
.000022
180
190
200
210
220
230
240
250
260
-.00177
A.00168
-.oo 154
-.oo 133
-.00105
-.00075
-.00042
-.00017
.00008
.ooooO
-.00038
-.00058
-.00070
-.00078
-.00082
40089
-.OOO95
-.OOlOO
.oooooO
-.000022
-.oOOO63
-A?00132
-.000232
-JO0357
-.w
-AI00422
-.000434
270
280
290
300
310
320
330
340
350
.00034
.00058
.00080
AI0107
.00140
.00170
.00195
.00210
.00220
-.00104
-Do1 12
-.00118
-00128
-JO136
-.00125
-.00105
:.OOO76
-JO038
-.000390
-A?00268
-.000130
AKNlOo2
Am0114
JO0205
.000277
AM0285
mO204
* *cad
LI‘3-----,~
Table B3.Wind Force Coeffkients
for Typical Paraboloid With Cyiindrical
‘WIND ANGLE
Q (DEG)
0
10
20
30
40
50
60
70
80
.00323
SKI323
JO320
.OO310
.00296
SKI278
AI0242
.00172
.00070
.OOOOO
BOO25
AI0045
.ooo6o
JO072
.00078
.ooo94
.00122
JO149
.oooooo
-.000072
-.000116
-.000133
-.000125
-.000083
-.oOOO22
.000058
JO0178
120
130
140
150
160
170
-JO028
-.00088
-At0138
-JO182
-.00220
-.00239
-.00245
-.00249
-.00255
.00160
.00154
Al0136
.00112
.00080
AI0059
JO045
.00038
40025
AI00251
Al00288
.000292
.000266
AI00237
.000199
.000158
.000112
.000059
180
190
200
210
220
230
240
250
260
-.00260
-Al0255
-Al0249
-XI0245
-.00239
-.00220
-.00182
-XI0138
-.00088
.OOOOO
-JO025
-JO038
-.00045
-.ooo59
-JO080
-.OOl i2
-JO136
-AI0154
.oooooo
-.000059
-.000112
-.000158
-.OOo199
-JO0237
-JO0266
-.ooo292
-AI00288
270
280
290
300
310
320
330
340
350
-AI0028
.00070
JO172
AI0242
AI0278
.00296
.003 10
.00320
MI323
-.00160
-AI0149
-.00122
40094
-.00078
-.00072
-.00060
-.00045
-BOO25
-.000251
-.ooO178
-.000058
moo22
.000083
.000125
.000133
XI001 16
.000072
90
100
110
Shroud
Table B4. Wi.& F orce Coefficients for Typical Grid Antenna Without Ice
WIND ANGLE
63@EG)
0
10
20
30
40
50
60
70
80
CA
xl0137
.00134
.00130
.00118
.OOlO4
Jo088
.00060
.00033
.OOOlO
.ooooO
.ooo26
.ooo46
.ooo59
.00067
.00070
.00072
.ooo70
.ooo64
.bOOOO
.oOOO43
.oooO74
.000098
.000115
MO127
JO0135
DO0142
.000126
JO062
.00070
.ooo73
.ooo71
.00067
.00060
Al0052
.00040
.ooo22
.000111
.000120
.000129
.000131
.000127
.000114
.000095
.000070
.000038
90
100
110
120
130
140
150
160
170
-.00013
-.00030
-JO048
-.00068
-JO086
-.00104
-.00122
-.00140
-.00150
180
190
200
210
220
230
240
250
260
-.OO152
-.ilolSO
-Ml140
-.oo 122
-Al0104
-JO086
-.00068
-JO048
-.00030
AMob
-.ooo22
-.ooo40
-.00052
-JO060
-JO067
-.00071
&IO73
-.00070
.OOOOOO
-.000038
-.000070
-.000095
.
-.000114
-Al00127
-.000131
-JO0129
-.000120
270
280
290
300
310
320
330
340
350
-JO013
.OOOlO
JO033
.00060
MO88
.00104
JO118
.00130
.00134
-.ooO62
-.ooo64
-.00070
-JO072
-.00070
-Al0067
-Al0059
-.ooo46
-JO026
-.000111
-.000126
-.000142
-AM0135
-.000127
-.000115
-.000098
-.000074
-.000043
Note: ln the absence of more accurate data for a grid antexma with ice, use wind force
coefficients for typical paraboloid without radome from Table B 1.
Table B5. Wind Force Coefficients
for Typical Conical Horn Reflector Antenna
WIND ANGLE
0 (DEG)
0
10
20
30
40
50
60
70
80
cq
.00338
.00355
JO354
Al0345
JO335
.00299
.00235
DO154
.00059
.ooooO
.oooo4
DO025
aoooo
BOO77
.00142
.00181
.00208
.00237
JO248
-.00005
-.00007
-.OOOOl
.OoOO9
.ooo23
JO035
.ooo44
mm46
.00040
BOO32
.00030
DO032
BOO27
.00021
.00014
.00007
.00003
90
100
110
120
130
140
150
160
170
-.00020
-AI0062
-.00088
-.00147
-JO225
-JO289
-AI0323
-AI0367
-.00375
.00245
.00240
.00235
.00225
AI0201
.00167
.00113
.00052
.OOOlO
180
190
200
210
220
230
240
250
260
-JO356
-.00375
-.00367
-.00323
-JO289
-AI0225
-.00147
-.00088
-BOO62
.ooooo
-.OOOlO
-JO052
-.00113
-.OO167
-AI0201
-.00225
-.00235
-.OO240
.ooooo
-.00003
-.00007
-.00014
-.00021
-.00027
-.00032
-.00030
-.00032
270
280
290
300
310
320
330
340
350
-.00020
.00059
JO154
.00235
JO299
JO335
.00345
.00354
.00355
-AI0245
-AI0248
-AI0237
-.00208
-.00181
-.00142
-.00077
-.ooo25
-.00004
-.00040
-.ooo46
-.ooo44
-BOO35
-40023
-.00009
.00001
.00007
.00005
Table BG.Wi.nd Force Coefficients for Typical Passive Reflector
WIND ANGLE
WDW
- CA
cs
.ooooo
.OOOOOO
-.000077
-AI00134
-.000180
-AI00198
-JO0208
-.QOO262
-.ooo225
-.000129
0
10
20
30
40
50
60
70
80
JO35 1
.00348
.00341
.00329
.00309
.00300
.00282
AI0178
.0007 1
90
100
110
120
130
140
150
160
170
-.ooo 10
-.00108
-.00235
-.00348
-JO348
-Al0360
-.00376
-.00390
-.00400
.00030
a0035
.ooo39
BOO36
.ooo29
40023
a0019
.00012
.00008
.000030
.000180
.000225
,000210
DO0148
DO0126
.000109
.000080
.000042
180
190
200
210
220
230
240
250
260
-.00403
-.00400
-.00390
-.00376
-.00360
-AI0348
-.00348
-.00235
-.00108
.OOOOO
-.00008
-.00012
-.00019
-.00023
-.ooo29
-JO036
-.00039
-.00035
.oooooo
-.000042
-.000080
-.000109
-.OOO126
-.OOO148
-.000210
-.bOo225
-JO0180
270
280
290
300
310
320
330
340
350
-.OOOlO
.0007 1
AI0178
.00282
.00300
.00309
Al0329
a034 1
.00348
-.00030
-BOO27
-JO023
-JO021
-.00018
-AI0013
-.00010
7-.OOOO8
-.00003
-.000030
.000129
.000225
JO0262
.000208
.000198
.OOO180
.oOO134
.000077
.00003
.00008
.OOOlO
.00013
JO018
.00021
.ooo23
.00027
TIAEJA-222-F
Wind Angle
r
Wind
Top View
Positive Sign Convention
Figure B 1. Wind Forces on Paraboloids and Grids
fl
Wind Angle
Top View
Positive Sign Convention
Figure B2. Wind Forces on Paraboloids With Radomes
Top View
Positive Sign Convention
Figure B3. Wind Forces on Paraboloids With Cylindrical Shrouds
.
Side Elev.
Top View
Angie
I
Fs
Wind
Figure B4. Wind Forces on Conical Horn Reflector Antennas
0 = Horizontal Wmd Angle
D = Width of Reflector
(A) PLATE VERTICAL
(SIDE VIEW)
0 = Vertical Plate Angle
D = Length of Reflector
(Horizontal Wind Angle = 0 or 180 Deg Only)
(B) PLATE TILTED
Figure B5. Wind Forces on Flat Plate Passive Reflectors
TLVEIA-222-F
ANNEX c: TABLE OF ALLOWABLE TWIST AND SWAY VALUES FOR PARABOLIC
ANTENNAS, PASSIVE REFLECTORS, AND PERISCOPE SYSTEM REFLECTORS
A
B
3dE
BCSII
WgirQ
DCflCZIiOfl
Angie
A;,”
Antenna
OdY
Note 8
Note 1
Note7
Len,l&lit&
Antenna
SlnJcture
Fhssivc
Movement
with
*ea
Movement
Twistof
Sway at
Antenna
Attachment
Felt
stn~ture
DJZFLEE.S DEGREES
F
C
D
parabolic Asnemas
Limitof
Limit of
DEGREES
iii
ii
:5
ii
E
ti
ti
$78
ifi
2.6
ii
4.0
i:!
1.9
1.8
1.7
i:
3:1
2i
iii
1.9
1.8
1.7
ii
0.2
S:Z
:;”
1.4
ii
20
19
1.8
1.8
:4
1.45
1.4
1.35
1.3
0”;
t:
::
if
i::
tS”
:I
4.6
4.4
0:4
0.4
4i
4.0
:;
i4
4.0
42
03
0.4
2’:;
21:;
::A
iI
0”;
:;
2”:
25
i4
22;
2J
2.4
2i
s-i
iI2
%
2”;
22
2.0
2.1
1.9
8:
ii
1.7
1.8
02
8:
1.4
:;”
82
1.5
1.4
1.3
1.2
1.1
0.9
i-7”
i6
1.3
12
:i
i::
X::
0:9
i:;
8;”
0”::
0.1
2
0.5
0.4
if:
0:1
z
22
::
i-F
ok
t :
1.4
::
1.1
1.0
0.8
0.75
0.1
0.1
1.5
::‘:
12
1.1
1.0
iii
8:L
8::
ii;
E5
iI;
ii:
::5
0.7
05
x;”
E
0.1
:::
::
0:1
0.1
iI:
ifi
Oi5
ii
0:3
ii-f5
02
0:07
i-f4
k
0:1
0.95
0.9
0.85
0.8
0.75
0.7
0.65
iii5
::
::
io
iI:5
::
iii
ii5
0.3
0.1
iii5
ii5
i-k
1:2
1.15
0.1
:f
1.15
1.1
:;6
0:1
8f5
:-:
lI5
1.4
:4
::;
zli
i..9
1.8
1.7
1.6
:-;
1:7
:-;
1:6
.
1.7
ill
z
A!!1
hint
iis
:J
33::
*Ft
kg2
22
i-i
3’::
struTwistat
DEGREES DEGREES DBGREBS DEGREES DEGREES DEGREES
i-i
::
0:3
2
I+iEzzt
Rigct
Stll!LR%
ii
4.2
4.0
;4
h!iSiVC
Reector
nviat
Note4
Ibfkcmc
S-Y
Note4
Nooe5
i::
3.8
E
-of
I
H
Paiscope system Refkmfs
ualitof
Limitof
Limitof
G
0”::
::i
8::
i-i7
0:05
&
82
0.15
0.10
0.13
0.05
0:1
OdY fOr c0nfiilion
where anunna
is dirmly under the nflecmr. ’ I
NOTE:
See Notes On Following page.
rl)
TIAEIA-222~
Notes:
a
1. If whes for columns “A” and “B” are not available from the manufacturer (s) of the antenna
system or from the user of the antenna system then values &ail be obtained fkom Figure CL c2,
or c3.
2.
Iimh of beta-nmovement for twist or sway (treated separatiy inmost anaiyses) will be the sum
of the appropriate figures in CO~UIIIIS C 9; b, G & H.-and G-&zL c-ohm&G, k & L appiY to a
Vertical periscope configuration.
3. It is not intended that the values in this table imply an accuracy of beam width determination or
SbuCtud rigidity calculation beyond known practicable values and computational procedures.
For most microwave structures it is not practid to require a calculated structural
rigidity of less
than 114 degree twist or sway with a 50 mi/h (22.4 III/S) Basic Wind Speed.
4. For passive reflectors the allowable twist and sway values are assumed to incbrde the effects of
all members contributing to the rotation of the face under wind load. For passives not elevated
far above ground (approximately 5 to 20 feet (1.5 to 6 m) clearance above ground) the stmcm.re
and reflecting face supporting elements are considered an integral unit. Therefore, separating
the structure portion of the defiection is only meaningful when passives are mounted on
conventional microwave structures.
5. The allowable sway for passive reflectors is considered to be 1.4 times the allowable twist to
account for the,amount of rotation of the face about a horizontal axis through the face center and
paraki to the face compared to the amount of beam rotation along the direction of the path as
it deviates from the plane of the incident and reflected beam axis.
6. Linear horizontal movement of antennas and reflectors in the amount experienced for properly
designed microwave antenna system support structures is not considered a problem (no
significant signal degradation atttibuted to this movement).
7. For systems using a frequency of 450 MHz, the half power beam widths may be nearly 2 @
degrees for some antennas. However, structures designed for microwave relay systems will
usud.ly have an inherent rigidity less than the maximum 5 degree deflection angle shown on the
chart.
8. The 3 dB beam widths, 2 0 HP in column
“A” are shown for convenient reference to
mamrfacmrers’ published antenna information. The minimum deflection reference for this
standard is the allowable total deflection aneie Q at the 10 d.B
TIAEIA-222-F
R=w@=
‘TV or ‘Tr
(feet)
10.
6%.
i
sm.
40.
a.
-
me
20.
--
7.8
IS.
6.0
s.e
10.
4.0
9.8
6.8
7.0
2.8
6.8
s.n
-
f
6.8
4.0
6.e
1.S
10.
3.0
f
+
i
Flatface~m
-on
2.0
1.s
~
lmifaml amplialde
’ Planor elevation of flat face
dkCt0rS
Note:Fortherotatiun.u of thenaectorabout
INS=ner. the defktion beam angie 0. may vary hm
l pO2u~accordancewiththe~sys~gFameay.
.
--w
e=.$&
l-l
Rectanguiar~squareapemrre
HiHVaFetheprojected
dimens~alongthebe~path
NOMOGRAPH, DEFLECTION ANGLE, 8
AT 10 dI3 POINTS FOR RIxT.GUUR
APERTLJRE
(FLAT FACE REFLECTOR)
Figure Cl
cIircu&
Paraboia
(degrees)
.10
(E)
m.0
.2a
IS.8
30
--
-40
.m
18.8
9.8
.m
~
1.8
0.0
7.0
6.0
s.0
4.0
--
T
I
6.6
2.6
S.8
3.8
4.8
v
.
4.8
3.0
3.0
2.6
2.6
1.s
1.S
1.0.f
Parabolic nzflector
1odBtapr
Circniar apemm
NOMOGRAPH. NOMINAL BEAM WlD-lH
3dBPOINrs
(TYPICAL PARABOlXXEFLECI.OR~
Figure C2
i
1.8
l+YirF
30.0
20.8
i
tS.a
10.8
--& 9.8
8.0
z
7.8
s
5.8
6.0
4.8
6.8
f
3.0
Tv
2.8
i
s.0
4.8
Q
1.5
*
-L
7.8
.
2.0
1.s
1.0
--
-
Parabolic reflecror
lOdEhap
60 ?L
Q’T
circular aperture
-
beamnorm2laxis
Plan or elevation
of parabola
NOMOGIUPH - DEFLECI’ION ANGIE
~1OdBPOINTSFORCIRCULAR~
(PARABOLIC SURFACE coNTouR)
Figure C3
0
1.0
(LEFTBUNK
lNTENTIONALLY)
IWEIA-222-F
ANNEXD:
DETERMINATIONOFALLOWABLEBEAMTWISTANDSWAY
LlMrrED SYSTEMS
CROSS-POLARIZATION
A dual polarized antenna has a pa-
FOR
either Em
Dl and D2. For most offset
antennas the moss-polarized null is &p as shown in Figure Dl; for most center-fed antennasthe
cross-polarized null is shallow and the envelope is as shown in Figure D2. In either case,as ~00x1as
the antenna is deflected fhm its normal pi&~
the cross-polarization disuiminatioa XPD (the
difference bemmn the co-polarized si@ 8IIcI the.c~~~~-p~latized
signal), decreases.
m
&at
&own
in
Where on-path cross-polarization &mation
is critical to system pesformance, allowable beam
ddkction
8 should be determined as shown in Figure Dl or D2. For &set-fed antennas,indUd@
horn reflector antennas,8 will determine twist only and the antennabeam width will determine
sway. For center-fedantennas,8 will determine both tit and sway.
a
--..w..
.--,
Figure D 1. Offset Fed Antenna
‘3
.*
0L
t
TIAEiA-222-F
Table D 1. Table of Allowable Twist and Sway for fiOSS-pO~tiOn
Lhhd
SYSAllowable Twist For Offset-Fed htennas.
Allowable Twist and Sway For CMter-Fed
Allowable Sway Foaoffset-&d Anmnas
Beam Twist
or Sway For
crossPolarizatim
Limited sys-
Movement
with Respect
To Structure
Movement
at Antfznna
Atcachmeat
P&t
DEGREES
DEGREES
i-:
0:3
0.2
0.1
ii-:
607
0.06
0.05
0.04
0.03
0.02
0.01
E
i
D
C
Limitof
3dB
SkUCture BeamWidth
32
2:7
i::
0.81
0.72
0.63
0.54
0.45
0.36
0.27
0.18
0.09
AtlOdB
PhIUS
DEGREES
5.8
5.6
5.4
5.1
4.9
4.7
4.4
42
;;
3’5
3%
3.1
iii
2.8
2.7
2.6
25
23
if
20
1.9
1.7
1.6
15
1.4
1.3
12
1.1
0.9
ii-;
i6
05
0.3
02
0.1
Note: See Notes on Following Page.
z-
2QHP
Par
-MY
5.0
4.8
4.6
4.4
4.2
4.0
;::
.
F
4
G
Limited
SkllCt’Xe
Sway
2tAxlmu
Attachment
Poillt
DEG=
4.6
4.4
42
4.0
3.8
3’;’
i:;
;3
2:9
2:
;;
;;
2.6
25
i=.=.
24
ki
ii
2.1
2.0
1.9
1.8
1.7
1.6
15
1.4
13
12
12
1.1
1.0
0.9
0.8
ii!
ii2
ii:
0.4
0.3
0.2
0.1
El
O>
025
Ei
2.2
2.1
2.0
1.9
1.8
1.7
1.6
1.5
1.4
1.3
13
1.1
Notes:
*
1. If values for columns “II” and ‘Y of the swaytable and column “A” of the twist table are not
available from the manufacturer (s) of the arnennasystem or from the user of the antenna system
then values shall be obtained from Figure C2, or C3.
2. Limits of beam movement for twist or sway (treated separately in most analyses) sre the sum
of the appropriate figures in columns 9” and T” of the twist table and the sum of the
appropriate figures in columns “F” and ‘%,, of the sway table.
3. Linear horizontal movement of antennas and refiectoxs in the amount experienced for properly
designed microwave antenna system support structures is not considered a problem (no
significant signal degradation attributed to this movement).
4. The 3 dB beam widths, 2 9 HP in cohuun “ID” are shown for convenient refmen- to
manufacturers’ standard published antenna information. The minimum deflection reference for
this standard is the allowable total deflection angle 0 at the 10 dB points.
5. The values shown in this table depict angular deflections in two orthogonal planes no& to the
boresight direction: vertical elevation (sway) aud horizontal azimuth (twist). No allowance has
been made for initial offsets due to mount skew, installation tolerances, paths not normal to the
suppon structures, etc. Special considerations will be required in those cases.
6. It is not intended that the values on this table imply an accuracy of beam width determination
or ~buctural rigidity calculation beyond known practicable values and computational
procedures. For most microwave structures it is not practicable to require a calculated structural
rigidity of less than l/4 degree twist or sway with a 50 mi/h (22.4 m/s) Basic Wind Speed.
.
1INEIA-222-F
-I&V.&IA-2X-F
ANNEX E: TOWER MMJWE&MCE
Of towers shadd perform zw
&mXs
and p&dic
AND JNSPECTION PROCEDURES
tower inspection and rnaintenanCeto assure
safety ami to extend s&m life. It k recommended that major inspections be performed, at a
-Urn,
every 3 years for myed towers and every 5 years for self-supporting tOWeS see section
14. Ground and aerial procedures shodd be p&omxxi only by authkized personnel, experienced
in c&bins and tower adjustments.
SOme Ofthe items listed below may apply only to initial cmstmction
I.
of new towers.
Tower Conditions (guyed and self-supporting)
A. Members
1. Bent members (legs and lacing)
2. Loose members
3.
Missing members
4.
Chding
facilities, platforms, catwalks - all secure
5. Loose and/or missing bolts
B. Finish
1. Paint and/or galvanizing condition
2.
Rust and/or corrosion conditions
3. FAA or ICAO color marking conditions
.
*
4. Water collection in members (to be remedied, e.g., unplug drain holes, etc.1
C. Lighting
1. Conduit, junction boxes, and fasteners weather tight and secmc
2. lhins
and vents open
3. Wiring Condition
4. Controllers functioning
a. Flasher
b. Photo control
c. Alams
5. Light lenses
6. Bulb condition (Option: change all bulbs at one time)
D. Grounding
1. Connections checked and secure
2. Corrosion observed and remedied
3. Lightning protection secure (as required)
E. Tower Base Foundation
1. Ground Conditions
a. Settlements or movements
b. Erosion
c. Site condition (standing water, drainage, trees, etc.1
2. Base condition
a. Nuts and lock nuts tight
b. Grout condition
3. Concrete Condition
a. Cracking, spalling, or splitting
b. Chipped or broken concrete
C. Honeycombing
d. Low Spots to collect moisture
e. Anchor-bolt corrosion
F. Tower Assembly Profile (See Figures El and E2)
1. Antennas and feedlines (e&h)
a. Frequency
b. Elevation
c. Type
d. Size
e. Manufacturer
f.
Connectors and hangers
2. Optional appurtenances (walkways, platforms. sensors, floodlights, etc.)
a. Elevation
b. Arrangement
c. Drawings or sketches
3. Foundation and anchors
a. Plan
b. Elevations (relative or true)
c. Size
d. Depths
e. Soil type (if known or necessary)
G. Tower Alignment (See Figures E3, E6, and E7)
1. ‘bmr
Plumb and l’kvist (See 6.1.2.1 and 6.1.2.2)
H. Insulators (As Reqtied)
1. Insulator Condition
a. Cracking and chipping
b. Cleanliness of insulators
C.
Spark gaps set properly
d. Isolation transformer condition
e. Bolts and connections secure
f.
Manufacturer type and part numbers for future rephmms
II. Guyed Towers
A. Anchors
1. Settlement, movement or earth cracks
2. Backfill heaped over concrete for water shedding
3. Anchor rod condition below earth (Maintain required structural capacity of anchor
during exploration, inspection and maintenance. Attachment to temporary anchorage may
be required.)
4. Corrosion control measures (galvanizing, coatings, concrete encasement, cathodic
protection systems, etc., refer to Annex J.)
5. Grounding (Paragraph I-D)
6. Anchor head clear of earth
B. Tower Guys (see Figures E4 and E5)
1. Strand
a. Type (1x7 EHS, 1x19 bridge strand, etc.)
b. Size
c. Breaking strength
d. Elevation
e. Condition (corrosion, breaks, nicks, kinks, etc.)
2. Guy Hardware
TIAEIA-222-F
a. Turnbuckles (or equivalent) secure and safety properly applied
b. Cable thimbles properly in place (if required)
c. Service sleeves properiy in place (if required)
d. Cable connectors (end fittings)
i.
Cable clamps applied properly and bolts tight
ii. Preformed wraps - properly applied, fully wrapped, and sleeve in piace
iii. Wire serving proPerly applied
iv. Strandvices secure
v. Poured sockets secure and showing no separation
(Note: Connectors should show no signs of damaged cable or slippage.)
e. Shackles, bolts, pins, and cotter pins secure and in good condition.
3. Guy Tensions
a. Tension should be compared to design requirement.
b. Tensions should be checked by acceptable methods (see Section IV and Figures Eg,
E9, and ElO)
C.
Notes:
Record tensions and weather conditions on attached charts (see Figures E4 and a)
.
1) Variations in guy tensions are to be expected due to temperature and wind. These are minor
variations. Should there be significant tension changes, the cause should be determined
immediately and proper remedial action taken.’ Possible causes may be initial construction
loosening, extreme wind or ice, anchor movements, base settlement, or connection slippage.
2) Tension variations at a single level are to be expected because of anchor elevation
differences, construction deviations, and wind effects.
Caution: DO not check or adjust guy
tensions
during times of excessive winds.
III. Antennas and Feedlines
A. Antenna Mounts and Antennas
1. Members (mounting and stabilizing)
a. Bent, broken, or cracked
b. Loose
c. Missing
d. Loose and/or missing bolts
2. Adjustments secure and locked
3. Elements
a. Bent, broken, cracked or bullet damaged
b. Loose
c. Missing
d. Loose and/or missing fasteners
4. Corrosion condition
5. Radomes and/or cover conditions
B. Feed Lines (waveguide, coax, etc.)
1. Hangers and supports
a. Condition
b. Quality
c. Corrosion condition
2.
Flanges and seals (check integrity)
3. Line Condition
a. Dents
b. Abrasions
c. Holes
d. Leaks
e. Jacket condition
4. Grounds
a. Top ground strap bonded both ends
b. Bottom ground strap bonded both ends
5. Feedline support (ice shields)
a. Properly attached
b. Loose and/or missing bolts
c. Members straight and undamaged
TIAGIA-ZZZ-F
TOWER ELEVATION
Show the following:
-
Tower Height above ground
Location of antennas
-
Figure El
Location of feed lines
Location of platforms, ladders, etc.
TIA/EL4-222-1:
PLOT PLAN
Show the following:
-
-
Tower layout relative to North
Anchors and assign letter designation
-
Relative or tme anchor and base elevations
Access roads and buildings
Power lines and poles
.
Figure E2
--
TOWER LEG VERTICAL
a
ALIGNMENT
1. Check with transit. %o transit setups are required Line transit paraiki to one face ad
center on leg. Second setup should be at 90” on same leg. Show on sketch below the
locations used for transit setup. Indicate North.
SelfSupporting
EIevations
Guy Level
Top to Bottom
Left
Transit #l
Tower Lays
0
Right
-amit #2
Tower Lays
Left
0
Cantilever Structure
1000’
10
--
900’
9
--
800’
8
--
700’
7
--
600’
6
500’
5
--
400’
4
--
300’
3
--
200’
2
100’
1
--
Approximate wind speed during measurements
mph
Note: This procedure is not sufficient to determine both twist and out of plumb.
See Figures E6 and E7.
Figure E3
Right
S-WAY GUYED TOWER
0
Guy Leg B
iGuy Leg B
Figure E4
I
I
I
6
5
4
3
2
1
I
I
I
I
I
I
I
I
. __---.
---
-
4-WAY GUYED TOWER
Guy Leg B
Note: See Note 2, Section II for
details regarding guy tension
checks.
Data: Date
TempIce -
Figure E5
Time
Wind-
d=(Dl +D2+D3+04)/4
a = amin
(e)
x=(D2-D4)/2
g=(DI -D3)/2
OBSERVED
MASTDATA
CALmTED
I
I
cflmJL4m
OUT-OF-PLUMB
Figure I%. Twist and Out-of-Plumb Determination for Square Towers
I
ATION FOR TRTANGUUJRIOl-JIST- AND OUT-OF-PLUMBDETERMlN
d=(Dl+D2+03)/
3
e = (dfi)/A
a = u&n (e)
I: = (D243)/fi
p=(2xDl
Figure E7. Twist and Out-of-plumb
Detexminath
-D2-D3)/3
for Triangular Towers
IV.
Methods For Measuring Guy Initial Tensions
There are two basic methods of measuring guy initial tensions in the field: the direct method
and the indirect method.
A. The Dimt Method (see Figure E8)
A dynamometer (load cell) with a length adjustment device, such as a come-along is
attached to the guy system by &mpmg onto the guy just above the turnbuckle and onto
the anchor shaft below the turnbuckle, thus making the turnbuckle redundant.
.
The come-along is then tightened until the original turnbuckle begins to slacken. At this
point the dynamometer carries all of the guy load to the anchor, and the guy tension
be read directly off the dynamometer dial.
may
One may use this method to set the correct tension by adjusting the come-along tumJ the
proper tension is read on the dynamometer. lI,vo control points are marked, one above
the clamping point on the guy and one on the anchor shaft, and the control length is
measured. The dynamometer and come-along are then removed, and the original
tu.rnbuckle is adjusted to maintain the control length previously measured.
B. The Mhxt
Method (see Figures ES and E9)
There are two Common techniques for the indirect measurement of guy initial tensions:
the pulse or swing method (vibration) (Figure E8) and the tangent intercept or sag
method (geometry) (Figure E9).
1. The Pulse Method (see Figures E8 and EiO)
One sharp jerk is applied to the guy cable near its connection to the anchor causing a
pdse or wave to travel up and down the cable. On the fust return of the pulse to the
lower end of the guy cable the stop watch is started. A number of returns of the pulse
to the anchor are then timed, and the guy tension is calculated from the following
equations:
TM = YLE
8.05P2
(1)
1lAWA-222-F
in which (seeFigure El@
TA = Guy tension at anchor (lb)
TM = Guy tension at mid-guy (lb)
W = Total weight of guy, including ins-,
L = Guy chord length (ft)
etc. (lb)
L=jrn
8)
V = Vertical distance from guy attachment on tower to guy attachment at anchor(fi)
H = Horizontal distance from guy attachment cmtower to guy attachment at anchor
(ft>
N = Number of pulses or swings counted in P secd~
P = Period of time measured for N pulses or swings (s)
Instead of creating a p&e that travels up and down the guy, one may achieve the
same result by causing the guy cable to swing freely fkom side to side while timing N
complete swings. The formulas given above wilI aiso apply fix this approach.
2. The Tangent Intercept Method (see Figure E9)
A line of sight ik established which is tangential to the guy cable near the anchor end
and which intersects the tower leg a distance (tangent intercept) below the guy
attachment point on the mast. Th& tangent intercept distance is either measured or
estimatedand the tension is &cu.&d kom the following equation:
.
WCJiiTyiq
’
TA =
HI
(4)
in which
C = Distance from guy attachment on tower to the center of gravity of the weight W
et>
I = The tangent intercept (ft)
If the weight is uniformly distributed along the guy cable, C will be approximately
equal to H/2. If the weight is not uniformly distributed, the guy may be subdivided
into n segmentsand the following equation may be used:
TA =
SJm
HI
0
in which
N
S = c WC,
(6)
.
-
Wi = Weight of segment i (lb)
Ci
= lkaXe
from the guy attachment on the tower to the center of gravity Of
segmenti (ft)
If the intercept & dlfficdt to establish, one may use the guy slope at the =&or end
with the following equation:
TA = WCJl
(v - Hm a)
m
in which
01= Guy angle at the anchor (see Figure E9)
Note that
I = v - Htan a
(8)
and that
ami that WC in equation (7) my be replked with S, as was done in equation (5).
DYNAMOMETER
DYNAMOMETER
COME-ALONG
TURNRUCKLE
METHOD
AS COME-ALONG IS TIGHTENED
DYNAMOMETER
CARRIES FULL
LOAD WHEN TURNBUCKLE IS
FULLY SLACKENED
(NUTS BREAK FREE). ,
PULSE METHOD
SWING METHOD
PULSE TRAVELS UP AND DOWN
THE GUY N TIMES
IN P SECONDS.
0
GUY SWlhS
FROM a TO b
AND BACK N TIMES
IN P SECONDS
0
Figure E8. Methods of Measuring Tnitial Tension
C
t-i
t
I
Figure E9. Tangent Intercept Method
nn
.
V
‘
/
/
/
‘T
M
Figure ElO. Relationship Between Guy Tension at Anchor and at Mid-Guy
ANNEX F: CRITERIA
FOR THE ANALYSIS OF EXISTING
STRIJC-~URES
Periodic revisions to this standard a made by t&e Commitkz based upon comments received from
the industry.
The committee does not intend that tit&g
structures be analyzed for eachrevision of the standard;
however, structural maiysis of existing structuresshould be performed by qualified profes~on~
engineers using the latest edition of this standard when:
a) l”h=e is a changein antennas, transmission lines, and/or appurtenances (quantity, size, location,
fx type)
b) There k a change in operational re.qui.rements(tit
and sway)
c) There is a need to increase wind or ice loading
To perform the analysis, the following data is rquired:
a) Member sizes, dimensions, and connections
b) Material properties
c) Existing and proposed loading; antennas (size, elevation, and azimuth), transmission lines, and
appurtenances
Data may be obtained from the following sources:
a) Previous stress and rigidity ~IU$& (structure and foundation)
b) Stn~tural
and detail drawings (design and as-built) ’
c) Specifications
d) Construction records
e) Field investigation
a
(LEFTBLANK
INTENTIONALLY)
TWEiA-222-F
ANNEX G: SI CONVERSION FACTORS
COnV~iO~ CO~Ody
required using EIA/EA-222
for the Intemational System of Units
To Convert From
To
Multiply By
inches (in)
millimeters (mm)
25.40
feet (ft)
meters (m)
0.3048
square feet (ft2)
square meters (m2)
0.0929
cubic feet (ft3)
cubic meters (m3)
0.0283
pounds [force] (lb)
newtons (N)
4.4482
pounds per cubic feet
kilonewtons per cubic meter
rw~gw (pa
Wh3>
pounds per square foot
Wfi2)
P=&
(Pa)
47.88
kips per square inch (ksi)
megapascals @lIPa)
6.8948
miles per hour (mi/h)
meters per second (m/s)
0.4470
0.1571
[Sri
m
-------
-.
(LEFTBLANK
INTENTIONALLY)
ANNEXH:
COMMENTARYON
ICEDESIGN CRITERIAFORCOMMUNKATION
STRUCTURES
1
INTRODUCTION
The meteorological phenomenon
of ice
accumulation is very difficult t0 predict with
certainty. For tower and pole structures, ice accumulation can be one of the predominant
applied loads.
The first task in developing ice design criteria is to determine if the proposed or existing site
is susceptibleto icing. If the site has a history of ice accumulation, the fiquency, thickness,
type ad duration of icing must be determined Potential sourcesof this Mxmation inch&
the National Weather Service (NWS), local weather agencies, owners of existing towers at
the same site or nearby sites, local landowners, and consulting meteorologists.
Judgmentmust be exercised to detexmine if reported icing events are frequent-or rare
ommnces.
Likewise, in some geographical areaa, seasonal high winds and icing OCCUT
simultaneously: For these situations, simultaneous application of maximum wind and ice
loadings may be required.
The effect of icing on a tower generally
relates
directly
to the type and size of tower and to
the we and thickness of icing. For example, a l/Z-inch radial ice accumulation will have
more impact on a short tower with small members than a tall tower with larger members.
Very dl tmers may experience large thicknesses of in-cloud icing over portions of the
mast. Solki or clear glaze ice has a higher density than that of rime ice or hoarfrost.
Consequently, the effects of increased dead *eight from ice accumulation will vary
depending on the type of ice. Large accumulations of rad.iaI ice can dramaticaIIy increase
the projected wind area of tower members and antennas.
a
2
TYPES OF ICING (1) (2) 0)
There are several types of i&g which can accumuiate 011COm.Ulum
‘&on
important to understand where and how they form.
2.1
sQwZUlZS. It iS
Hoarfrost
Hoarfrost is a fluffy 0~ feathery deposit of interkking ice crptd
formed on
objects, usua~y those of d
diameter fialy exposed to the air, such as tree
branches, wires, etc. ‘I&e deposition of hoarfrost is similar to the process by which
dew is formed, except that the temperature af the &osted object must be btiow
freezing. It forms when air, with a dew point below kezing, is brought to saturation
by cooling. Hoarfrost has densities less than 19 lb@ [3 kNjm3].
2.2
RimeIce
Rime ice is a white or m.i,ky pm&
deposit of ice formed by the rapid freezing of
supercooied water drops as they impinge upon an exposed object. It is denser and
harder than hoarfrost, but lighter, softer, and less transparent than glaze. Rime is
composed essentially of discrete ice granules and has densities ranging from 56 w
19 WfG 19 to 3 kNjm3].
Rime is often described as soft or hard. Soft rime is a white, opaque coating of fine
rime deposited especially on points and eilgcs of objects. It is usually fmed in
supercooled fog. On the windward side, soft rime may grow to very thick layer%
long feathery cones, or needles pointing into the wind and having a structure S&.&U
to hoarfrost.
Hard rime is an opaque, granti maas ofi rime fanned by a dense supercooled fog.
Hard rime is compact and amorphous and may build out into the wind as glazed
cones or feathers. The icing of ships and shortit structures by supercooled spray
usually has the characteristics of hard rime.
2.3
Glaze Ice
Glaze ice is a coating of ia, generally clear ‘aud smooth, but usually containing some
air pockets. It is formed on exposed objects by the fretzing of a film of supercooled
water, usually deposited by rain or drizzle. Glaze is denser, harder, and more
transparent than either rime or hoarfrost. Its density may be as high as561b/ft3
C9kN/m3].
*
(1) AtmosphericIcing on S-s.
Boyd& Williams.
(2) Draft Guidelines for Transmissim Line Sati
Ldhp.
AXE
(3) TaaeJman.
P..andGring~rten. LL. “EstimatedGlaze Ice andWrndLoadsat &e ws ~R&x for the
CQIX@OUS
UnitedStates”.Air Force&bridge ~esearcfr
m.
B4fo1& Massachusetts.
1973.
____--- - --
3
CONDITIONS OF ICE FORMATION
‘be me of ice formed is determined by combinations of air temperature, wind speed,&oP
size, and liquid water content or rainfall intensity. The icing problem, therefore, can be
&Gfkd
either by the meteoroIog&I conditions that produce the formation of ice or by the
type of ice that is formed
3.1
Precipitation Icing
This is the most Common icing me&n&m and can occur in any area subject to
freezing rain or drizzle. The ice is formed when warm, moist air is forced Over a
sub-freezing, denser layer of air at the ground surface. As the watm air rises and
condenses, rain falls through the coider air and freezes on objects near the ground.
This frozen deposit is a clear glaze type of ice. Since this kind of weather is caused
by frontal activity, it usually doesn’t last more than a day or two.
Because it is necessary for excess water to be present for glaze to form on exposed
surfaces, often the excess water may freeze into icicles or other distended shapes.
In actd practice, glaze ice can be seen to form on cables and guys in a variety of
shapes ranging from the classical smooth cyhndxical sheath, through crescentson
the windward side and icicles hanging on the underside to large irregular
protuberances spaced along the cable. In most cases, glaze ice develops on
st.nmms as a fairly smooth layer on tie windward surfaces with icicles forming
below horizontal members. The shape of the glaze is apparently dependent on a
combination of factors, such as wind speed, variations in wind speed, the angle of
the wind, the turbulence of the flow, variations in air temperature and duration of the
Storm. Since most of these factors vary @om storm to storm, and even during the
storm a @i.ndticai shape of equivalent weight is assumed for design purposes.
3.2
In-Cloud Icing
This type of icing condition is caused by the impingement of super-cooled water
dropiets of a cloud on the structure or cable. This is rime ice. It can occur in
mountainous areaswhere ciouds exist above the freezing level or in a super-cooled
fog at lower elevations produced by a stable air mass with a strong temperature
inversion. These conditions can last for days or weeks.
The total amount of in-cloud ice deposited is dependent on wind speed. Since wind
speed increases with height above ground, larger amounts of ice will occur towards
the top of taller towers and on the cables that support or are mounted on taller towers.
.
ANNEX I: GEOTECHNICAL
IWESTIGATIONS
FOR TOWERS
A ~0i.i investigation by a geotecfinical @n&g
firm is recommended for each tower site to
determine its unique soil and physical &ract&&cs,
and to provide data to develop safe design
p==eters,
economical foundation &maths,
ami installation procedures. To ensure that the
EPOn furnishes useful information to the foundation designer, the ‘geotechnical firm should be
provided with the following information:
a. A plot plan and site location map with tower, equipment building and other site improvements
located.
b. Tower base vertical reaction and shear and anchor vertical and horizontal reactions for guyed
towers; or i’rhkrn~m compression and tension (uplift) reactions with shear for self-supporting
towers.
C. Any special conditions or requirements of the specifications.
d. The minimum depth of borings for guyed tower bases should be 15-20 ft; for guyed tower
anchors lo- 15 ft; for self-supporting towers, boring depth will vary depending upon the type of
foundation being considered. The magnitude of the structure reactions, site and sod COndiuons
may require altering the boring depth requirements.
The geotechnical report should provide the following information at minimum:
a. Boxing logs.
1. Date, sampling methods, and number and type of samples.
.
2. Description of the soil strata according to the Uxkied Soil Classification System.
3. Depths at which strata changes occur referenced to a site datum.
4. Standard Penetration Test blow
counts.
5. Soil densities.
6. Elevation of free water encountered and its level after 24 hours, and recommended ground
water elevation to be considered for design.
7. Maximum and average depth of frost penetration.
b. Other soil characteristics or properties which may be required because of local conditions.
(Refer to Annex J for corrosion control options for guy anchors in direct contact with soil.)
c. A description of alternative foundation methods with recommendations for ultimate values for
passive pressure, bearing pressure and shin friction, the angle of internal friction and other
appiicable soil properties and appropriate safety factors.
lin
ANNEX J: CORROSION CONTROL OPTIONS FOR GUY ANCHORS IN DIRECT
CONTACT WITH SOIL
1
INTRODUCTTON
WY gUY mChOfi in direct contact with soil, designedin accordance with ETA/IIA Standards,have
performed We.ii without detrimental corrosion. However, depending on the required design life of
the stmture and on site-specific conditions, corrosion control measures, in addition to hotAp
gdvmg,
may be required to prevent the premature deterioration of these types of Eu1cfior~
Hot-dip galvanized mater& have been proven m be very effective in resisting corrosion when in
direct contact with soil. In a lo-year study involving 45 types of soils performed by the National
B=au of Standards, only one sample had some penetration of the base steel. A 13-year test in
ciab
( Oneof the most corrosive subgrade enti~nments), indicated that corrosion was effectively
reduced, even thou& the zinc coating was destroyed within the first two years. One theory for this
b~vh
is that the alloy layer between the zinc and steel surface, formed during the hot-dip
&V&g
process, results in a major source of protection. Also, in some soils, a protective layer of
*
a zh compound fmm during the corrosion process, slowing the rate of corrosion.
Despite the protective nature of hot-dip gakmixed materials, there have been reports of
unacceptable adm corrosion occurring within 10 years after installation. Anchor inspectionsare
W=dve
to de-e
if accelerated corrosion is occurring at a given site. Corrosion activity may
VarY widely across a site. Anchor corrosion could occur at one or more of the anchors at a site and
axid O~X at anY depth along a given anchor. Some of the site conditions which may result in
accelerated corrosion are briefly described in this annex. Under these conditions, additional
comsion control measures should be co&k&.
I This annex is not intended to be a treatise on the subject of anchor corrosion but is provided to heip
owners become aware of the potential anchor corrosion problems and the importance of anchor
inspections; and to encourage owners to pursue further information from appropriate specialists for
both new and existing construction. A corrosion specialist may recommend methods to curtaiI or
monitor corrosion discovered at existing sites or present options to consider for proposed sites.
2
“IVES
2.1
OF CORROSION
Galvanic Corrosion
Galvanic anchor corrosion occurs in soil when a self-generated current exists due to the
connection of dissimilar metals or due to non-uniform conditions existing along the surface
of an anchor.
When a dissimilar metal is electrically connected to an anchor, a difference in potential
exists between the two materi&. If the dissimilar metal is also in contact with a low
resistivity soil, a complete circuit will exist. Current will flow from one metal to the other
due to the electrical connection and return through the soil completing the circuit. This
naturally occunin g phenomenon is why current is obtained from a battery when its terminals
are electrically Connected.
Dissimilar metals behave in this manner because of the difference in potential each metal
inherently has. Metals may be listed in order of their potential. Such a list is called a galvanic
series. A galvanic series of commonly used metals and alloys is given in Table Jl.
When a complete circuit exists, corrosion occurs on the metal listed higher in the galvanic
series. This is the location where current exits and travels through the soil towards the metal
111
listed lower on the galvanic se&. For example, if a large copper ground Systemin a
conductive soil is directly or i&,rdy
@rough guys) ekctridy connectedto a steel
anchor, corrosion will occur on the anchor&cc steel is listed higher on the galvanic series
than copper.
The rate of corrosion wiU dependlargely on the a&uctivity of the soil and the relative
locationsofthemetalsinthegalvanicstrics.Thehi9)lnthtsQil~u~~~,andthc~er
apart
the metals
are in the gaIv&~
s&,
the fas&z the &osion.
Many 0thfZ f=tOrS
beyond the scope of this commentary could innuence the rare of corrosion and result b
=&med
anchor carrosion.
Galvaniccorrosionmay alsooccur~~~~rateswithouttheprrsenccafa~metal
when conditions along the surface of the anchor are not uniform. ‘Es situation may exist
The moist concrete, being much
when the base of the anchor is embeddedin COOCTC~~.
different than the soil surrounding the expo& portion of the anchor,will have a different
potential. If the surrounding soil conducthi@ is high, afdemed corrosion of the anchor
moisture
may occur. Backfill conditions with n~-unif~
composition, compaction,
wntent, porosity, etc., may result in similar localized difkcnces in potential along the
anchor.
2.2
Electrolytic Corrosion
Electrolytic corrosion is very S+
to @~a& msion. The differencebeingthe current
responsible for electrolytic corrosion is from an outside source as opposed to a
self-generated current which is responsible for galvanic corrosion. Outside sources of
current which may result in eiectiolytic ~sion
inch& ckctric rail transit systems,
mining operations, welding a&vi&s, mnr.hincry, or the corrosion control systems for
.,
pipelines or nearby stcuctur~.
For electrolytic corrosion to occur, the md,hg
soil must be conductiveand a CWTtnt
from an outside source must enter and tit an anchor on its path to a hcation Of lower
potential. At the point of entry, the anchor is generally unaffected.At the point of exit, BS
with galvanic corrosion, acceleratedcorrosion may occur.
3
CORROSION POTENTIAL OF SOL
The corrosion potential at a given site is a function ofmany variables:Fortunately,one of the most
important variables, the conductivity of soil, may be determinedby a geotectical investigation.
3.1
Soil Conductivity
The conductivity of a soil is usually deby measuringrcsistivity. Resistivity is most
often measuredin units of ohm-centimeter (&m+m). 7&e lower the resistivity, the higher
the conductivity. For example,salt water, a very mosive environment,has a resistivity of
approximately 25 ohm-cm. Cleandry sand,which is usually a non-corrosive environment,
may havea resistivi~ of more that 1,000,000ohm-cm. A soil with aresistivity below 2,000
Ohm-cm is generally consideredto be highly carrosive.
0
3.2
Other Factors
soil resisfivity may vary seasonablyand is gcnemlly a function of mine!ralcomposition,
moisture content and the concentrationof dissolvedsalts. Clays and high moisture content
soils generally have lower resistitiq &an sandsor low moisture contentsoils. However, a
113
dry sandysoil may becomevery aggressiveuponanincreasein moisturecontentif dissolved
Saks ax present. Likewise, a wet soil my not be aggressivewithout the presenceof
didvd
salts. TemperatureE&O affects resistivity values. The resistivity of a soil may @
me-e vefy high if measuredunder nearfreezingconditions,yet bevery aggressiveunder
wanner wnditio~.
MAY 0th~ factors influence the corrosion potential of soil to varying degrees.Someof
&se famm are: drainage, soti porosity (aeration), acidity or akalinity @h), certain
~miml iqmti~,
the metabolic activities of certain micr~+~@sIE, adjacentand/or
~~O~C~Y pmead stnrctures.Thesefactors may also vary seasonablyor vary due to
0th~ ~thities at a site,suchasthe doping of soil to increasethe efktiveness of agrounding
system. Due to the my possible’ factors i~~volved, it may not always be possible to
&mm&e the controlling factor when acceleratedcorrosion occurs.
3.3
GeotechnicalInvestigations
When a geotechnicalinvestigation is performed,asa minimum, thelocal soil resistivi~ and
the type and wncentration of dissolved saltsshould be established.With this information,
together with a description of all existing and/or proposed construction, a corrosion
spm*t shdi beableto recommendvariouscorrosioncontrol measuresto beconsider&
Additional site testingmay berequired by thecorrosionspecialistin order to properlydesign
ad implement a Corrosioncontrol system.
4
OPTIONS FOR CORROSION CONTROL
None of the following options for wrrosion wntrol eliminate the needfor proper monitoring and
maintenance over the life of the structure.
l
4.1
Site Modifications
.
Improving drainageor placing an impermeablelayer of soil at an anchor location may be
beneficial in reducing the rate of corrosion. Under some situations it may be possible to
ba&ill afouIlcl sn anchor with a high resistivity soil. Adding chemicals to neutralize
existing corrosive soils or to mitigate the actions of micro-organisms may also be sn
alternative. Caremust be taken to ensurethat the required structural capacity of an anchor
s~ppt
is maintained during excavationsand to avoid contaminating the local soil with
toxic substances.Relocating sn anchormay alsobe a reasonablealtemative if the causeor
possibility of acceleratedwrrosion at a site is known to be a localized, isolated condition.
If coppergroundrods serveasgrounding for ananchor,replacingthemwith galvanizedsteel
rods would reduce galvanic corrosion by el’ ’ .* g the presenceof a dissimilar metal.
Special attention should be paid to the ground lead and its connectionto a galvanizedrod,
particularly when the connectionis placed below grade.
Isolation Of anchors from the structure using guy insulators may help to reduce the
transmission of stray currents from outside sourcesand therefore minim& ekctrolytic
corrosion. Galvanic corrosion due to the presence of copper ground rods would be
eliminated if the ground wires were connectedon the tower side of the isolation point.
Isolation may also increasethe efficiency of sacrificial anodesdescribedin 4.4. Bonding the
anchorsto adjacentcathodicallyprotectedpipeliuesor structures may protect the anchorsss
opposedto subjectingthem to possible ekcsolytic corrosion. This should only be donein
accordancewith recommendationsfrom a corrosion specialist.
a
4.2
4.3
Protective Coatings
co&ngs are available. Theeffectivenessofa
Many types of organicm&orga&prote&e
coating is highly dependentupon the preparation of the anchor aUrfa% the method Of
application and the v&nerabfity of the coating to e
during cwStructk)n- Rotective
coatings may be particularly effectve when usedin conjunction with a cathodicman
sys- describedin 4.4.
Concrete Encas~~t
Direct amact with soi my beavoidedby ~g~~onYifh~orcedcon~~0~~
the entire embeddedlength of an anchor The encasementshould extend a minimum of +
inchesabovegrade.~~acwMete~~~blockisusedwithan~~,thtreiaforeingin
the concrete encasementmust be prop&y developed into the anchar block t0 prev=t
~wssive cracking.
Sulfate resisting coll~ctc e &sip should be used for all wncrete
below gd when soluble sulfatesexist in the soil or ground~atcr=
4.4
Cathodic Protection
For both galvanic and electrolytic corrosion,corrosion occurswhen current fi~ws from the
anchor into the surrounding soil. me objective
of cathodic protection is to reversethe
dir&on of current, resulting in current flowing to the anchorinsteadof away from it, thus
preventing corrosion of the anchor.This may be accomplishedby installing galvanicanodes
or by ~tmhing an impressedcurrent.
BY “iectrically connectinga metal (galvanicanode)hatedhigher on the galvanic series and
burying it in close proximity ment w be f&ed to fhw to the protected item from the
anode. This will resdt in corroSi0n of the installed metai an&
instead of the item to be
protected.Forthisreason,theinstalledmetalis~asacrificislaMdesadalsowhythese
anodesmust be periodically ir;spectedto &
sure they have not corroded away beyond
use. Additiimal stid
anode material by cvemdly have to be added. A common
mixturetoenhanceits
~acrificiaianodeusedismagncsiumpackagedina~p~bar?kf?ll
conductivity with soit.
The number,size, type andlocation ofgalvanic anodesshould be determinedby a corrosion
specialist and must be adequateto ensurem
flows in theecomxt direction, overcoming
the efkts Of ail other influences at the site. The efkliveness of an installed SyStemShould
bepcriodicallymonitoredoverthelifeofthestructure byacorrosionspeciahst.Thismaybe
done by measuringthe potential of the protectedanchorwith respectto a rckence electrode
placed in the ground. A Largeenoughnegativepotential indicates that current is flowing to
the ~dxxs as desiredfor corrosion control.
anodes
to cssurc
current
will
flow
Under certain circumstances,installing ~IIOII~~I gahnic
in the desireddirection may not be feasibleor eccmtical. Using animpressedcurrentwith
ananodemayberequiredunderthesecircumstances.Theimprtsstdcumntrequinstheuse
of a reliable power sourceto producethe’&sired current The positive tuminal of thepower
sowe is wnnected to the anoderesulting in current traveling from the anode,through the
SOfi to the anchor, overcoming the effects of all other infhrences. Since cutrent would be
entering the sxhor from the soil, corrosion of the anchorwould be controlled. The voltage
of the POW=some, the size,location andtype of anoderequired, andthe possibleeffectson
adjacent stnmm should be determined by a ccurosion specialist. overprotection may
1lA
result in accelerated coxrosionof surroundingstructuresandmay alsodamagetheax-&or or
anchor coating as a result of&# current hning
hydrogen gas at the anchor.
undeisirablechemicalcompoundsand/or
5
REFERENCES
wg, H. H., “‘Ibe Corrosion Handbook”, John Wiley & Sons,NY, 1948.
mg, H. H., Revie, R. W., “Corrosion and CorrosionControl”, Third Edition, JohnWhey Bi Sons,
NY, 1985.
W&O% C. L., oat=, J. A, “Cmosion and the MaintenanceEngineer”, Hart Publishing Company,
NY, 1968.
Huock, B., “‘F~chmds
Ohio.
of CathodicProtection”, HARCO TechnologiesCorporation,Mexiina,
TABLE Jl
GALVANIC
SERIES OF COMMONLY
USED METALS AND ALLOYS
MAGNESIUM
ZINC
ALSTEEL, IRON
LEAD,m
:
BRASS, COPPER,,BRONZE
SILVER
GRAPHITE
a
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