Civil Engineering Reference
In-Depth Information
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POLE APPLICATIONS
The two types of prestressed concrete poles predominantly used in the
electrical utility industry are centrifugally cast (commonly referred to as
spun cast) and statically cast. Spun poles have a round or a polygonal
cross section with a hollow core that is created by the spinning process.
The size of the hollow core depends on the pole diameter and wall thick-
ness. Statically cast poles have a square or polygonal cross section with a
core that is solid or a hollow core formed by a retractable mandrel or a
permanent form.
Prestressed concrete poles are an engineered product for which unique
designs and closely controlled manufacturing processes are performed.
Although both centrifugally cast and statically cast poles are referred to
as prestressed concrete poles, each has differences in performance, speci-
fi cation, and recommended use. These differences will be highlighted
throughout the document.
Recent technological advances in centrifugally cast products have pro-
duced multiple-section poles, including hybrid poles with concrete and
tubular steel sections. These multiple-section poles, using slip-fi t or bolted
fl ange splices, make possible longer poles and greater versatility than can
be attained by single-piece poles.
A word of caution should be mentioned regarding the application of a
prestressed pole in a different manner than the originally intended use.
An example is a pole that was originally designed as a single-pole tangent
structure but is now being considered for reuse as a small angle structure
(with reduced wind span length perhaps), or a guyed dead-end structure,
or an H-frame leg in which the original pole design may have insuffi cient
embedment length, service load cracking capacity, or ultimate load capac-
ity for the new application. It is therefore prudent that the Manufacturer
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