Civil Engineering Reference
In-Depth Information
The point of structure fi xity at or at some point below the groundline
should be specifi ed. Secondary loads imposed on the structure because of
foundation rotation should also be examined. The type of foundation
used will determine the degree of foundation rotation that should be
considered. (Chapter 8 discusses foundations.)
Any special defl ection limitations and the conditions under which
these requirements must be met should be provided. Defl ection limita-
tions generally are used to maintain proper clearances from the structure
and its attachments to other objects and the edge of right-of-way ease-
ments. They also may be necessary because of required equipment toler-
ances, such as those on switches. Additionally, defl ection limits are used
for aesthetic reasons. A pole that has excessive defl ection will appear to
be bowed and could be aesthetically unpleasant. Defl ections can be con-
trolled by increasing the structure stiffness or by raking the structure.
Increasing the structure stiffness to control defl ection generally will
increase the structure diameter and cost.
Weight of a concrete pole should be considered when evaluating its
use. Thoughtful consideration should be given to how the structure sites
will be accessed and how the poles will be delivered and erected.
The Manufacturer should consider the loads imposed on the pole by
the loading, unloading, hauling, assembly, and erection of the structure
(see Fig. 2-1). The Manufacturer should clearly indicate on the pole the
proper lifting points for the structure and should provide the user with
any special handling procedures that are recommended during the ship-
ment and erection of the structure. If single point pickup is required, this
should be communicated clearly to the Manufacturer and may result in
additional pole cost. (See Chapter 8 for more details.)
Attachments to concrete poles can include but may not be limited to
shield wires, insulators, and structural supports for conductors, guy
wires, ground down lead clips, climbing and working ladder clips, sup-
ports for equipment (such as switches or distribution equipment), danger
signs, and aerial markers.
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