Interstate 10 Widening Project Relocate 138kV Circuits to Underground

摘要

In 2003, highway construction began on a 22 mile stretch of Interstate 10 from near downtown Houston west to Katy, Texas. This segment of the interstate is known to Houstonians as the Katy Freeway. The 2.8 Billion dollar project will widen the freeway from 11 lanes to as many as 22 lanes when counting feeders and express lanes. Many businesses, residences, and utilities were affected by the increased highway right-of-way needs which included a six mile two circuit 138kV transmission corridor aligned parallel to the freeway. Given the number of utilities having to be relocated, the Texas Department of Transportation (TXDOT) mandated that these two 138kV circuits would have to be installed underground. Five substations would be affected, with three of the substations in this six mile segment requiring major modifications and bay reconfigurations. The underground transmission installation was divided into three logical phases beginning with the east end overhead to underground transition at the Marq*E Center west to Wirt substation. Phase 2 continues from Wirt substation to Echo substation, and Phase 3 includes Echo substation to Sauer substation. Construction began on Phase 1 in November, 2003 and was completed and energized in early September, 2004. Total completion of all three phases is scheduled to be August, 2006. This report discusses the design challenges, construction, and commissioning of the installation of the 6 mile underground segment of 138kV transmission circuits.