The Chesterfield Power Station, owned and operated by Dominion Power, is the largest fossil-fuel power plant in Virginia. Installation of a new flue gas desulfurization system at Units 3, 4 and 5 enabled the utility to provide clean energy at this facility by removing up to 95 percent of sulfur dioxide and 90 percent of mercury emissions.
The retrofit posed design and construction challenges due to its location in confined areas with low headroom. Our solution placed new piles and earth anchors between existing utilities, pipelines and foundations that could not be disturbed. The site constraints, as well as vertical, lateral and uplift loading conditions, dictated that up to five foundation types be used: micropiles, auger cast piles, drilled shafts, H-piles and spread footings.
A secant auger cast pile wall was also designed to brace an excavation adjacent to an existing 10-foot-diameter concrete water line, which was critical to keeping the power units online.