Valley Metro Light Rail Power Infrastructure Relocation

Project Description:  With the commencement of Valley Metro Light Rail Extension project, Arizona Public Service (APS) and other utility owners around downtown Phoenix found many of their existing substructures were in conflict with the proposed light rail track design. To avoid the disruption of large-scale relocation of entire underground vaults and ducts in the already congested underground, APS opted to use the Voltek Expansion System to construct a Voltek composite panel structure next to the two existing electrical vaults, making one large structure and relocating surface manways out of the light rail footprint. W.A. Rasic Construction installed beam and plate shoring and facilitated the excavation efforts to depths of 12 feet. Existing utilities were supported, and portions of the existing electrical vaults were demolished via wall saws, hydraulic breakers, and jackhammers/chipping guns to allow the installation of the Voltek dual manhole structure. The Voltek-engineered composite panel system, measuring 20 feet x 10 feet x 8 feet high was installed with a concrete reinforced floor, and the associated steel structural support system and a concrete envelope were poured as well as the deck, combining the existing structure into one single electrical vault. For the entire project duration, the 12KV and 4kv electrical systems remained energized and all adjacent utilities were in service.