Steel Transmission Pole Structural Capacity Uprating for High Voltage Transmission Line and Substation Upgrade Projects

High voltage electrical transmission line and substation upgrade projects are placing increased structural demand on existing steel pole support structures. Transmission line and substation engineers face the challenge of finding economical solutions when existing steel poles are determined to be structurally overloaded due to the demands of wire upgrades, code changes, and line routing or substation layout modifications. When existing steel poles are determined to be overloaded, reinforcement solutions are available to increase the structural capacity of the poles. In specific circumstances, reinforcement and modification operations can be performed in the field offering advantages when compared to structure replacement operations. This paper discusses specific pole shaft and baseplate reinforcement solutions that have been designed and installed on existing American Transmission Company steel transmission poles to support upgrade projects. The information provided in this paper will provide a broad understanding of reinforcement options which increase the structural capacity of existing steel poles.