Golden Pass LNG 230kV Double Circuit FOUNDATIONS

摘要

This paper describes the foundation challenges involved in building a new 12-mile 230kV double circuit line. The project consists of 228 pole structures on base plated steel caissons. Portions of this line are located in a coastal salt marsh, adjacent to a state wildlife sanctuary. Other portions wind their way along an environmental superfund site, and through multiple refinery, petrochemical, and heavy industrial facilities that have been under continuous use since the early 1900's. Current environmental and wildlife restrictions as well as requirements for hurricane loadings ruled out many conventional forms of design and construction, as did restrictions imposed by industrial facilities along the route that severely limited access. Because of this, a decision was made to use helicopter construction over much of the project. Structures and caissons were designed and constructed in sections to allow the use of a helicopter to lift to its maximum capacity. The helicopter then transported and installed each section at its intended location. In some instances where the steel caisson foundations were too heavy for the helicopter to lift, they were manufactured in two pieces and field welded. The various foundations features involved in meeting an aggressive in-service date under difficult conditions are described in the paper.