TPC-15.11.03 - Construction of Overhead Lines Working Group

Robert Millies

The material presented in this design guide pertains to the design of foundations for conventional transmission line structures, which include lattice towers, single or multiple shaft poles, H-frame structures, and anchors for guyed structures. It discusses the mode of loads that those structures impose on their foundations and applicable foundation performance criteria. The design guide addresses subsurface investigations and the design of foundations, such as spread foundations (footings), drilled shafts, direct embedded poles, driven piles, and anchors. The full-scale load testing of the above-listed foundation types is also presented. This design guide does not include the structural design of the foundations nor the design of the structure. The foundation engineer should have an understanding of the magnitudes and time-history of various loading conditions imposed on the foundations in order to provide a suitable foundation to support the transmission line structures under the actual loading conditions that may be reasonably expected in actual service.

Revision of IEEE Std 524-1992. SUMMARY: This guide provides general recommendations for the selection of methods, equipment, and tools that have been found to be practical for the stringing of overhead transmission line conductors and overhead groundwires. The guide also includes a comprehensive list of definitions for equipment and tools used in stringing and for stringing terms commonly employed. This guide does not address special conductors such as those used for river and canyon crossing. These conductors may be custom designed and often may require special considerations.

Various approaches to good construction practices that could improve the installation of transmission line structure foundations are presented. Spread foundations, drilled shaft foundations, pile foundations, and anchors are treated. This guide is intended to be used as a reference source for those involved in the ownership, design, and construction of transmission structures.