Civil Engineering Reference
In-Depth Information
3.1.1
Fixity
: Fixity, unless otherwise specifi ed, will be assumed to be
located at the groundline.
3.1.2
Buckling on guyed poles
: Guyed structures shall be checked for
critical buckling to determine the ability to withstand the combined
effect of the vertical guy component plus the induced moment in the
pole. The Manufacturer shall assume fi xity at the groundline for
guyed structures and no preload in the guy wires unless specifi ed.
The Purchaser will specify the guy wire properties to be used in the
design including size, strength, area, modulus of elasticity, and any
stress reductions to be applied.
3.1.3
Handling requirements
: The pole design shall include allowances
for loads due to handling, hauling, storage, and erection without
failure (including an appropriate impact factor) when handled
according to the Manufacturer's recommendations and instructions
and reasonably accepted construction practices. The following han-
dling and erection loads are to be provided for:
3.1.3.1 Lift points: The handling of poles in the horizontal position
shall be accommodated by the provision of a two-point pickup,
with the center of gravity and two lift points specifi ed by the
Manufacturer.
3.1.3.2 Handling instructions: The necessary support criteria for
hauling and horizontal storage of poles shall be specifi ed by the
Manufacturer.
3.1.3.3 Pole installation: The pole shall be designed for a single-point
pickup for erection, located at a distance of approximately one-
third the pole length from the pole tip, with the butt of the pole
on the ground.
3.1.3.4 Special consideration: Unless specifi ed, the poles are not
required to be designed for a single-point pickup at the balance
point. If it becomes necessary to require this condition, it will be
called out specifi cally on the drawings or in the stated load
requirements furnished by the Purchaser.
3.1.4
Embedment depth
: Poles should be designed to an embedment
depth (or point of assumed fi xity) as specifi ed by the purchaser.
4. STRENGTH REQUIREMENTS
4.1 Ultimate Strength
Poles designs shall be based on the Ultimate Strength Method. Ultimate
capacity is defi ned as the point at which the pole fails, usually by crushing
of the concrete in compression when ultimate strain is reached. Factored
loads resulting from criteria given in loading tables or wire data,
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