Oregon Clean Energy: Combined Cycle Fuel-Fired Power Plant

Oregon, Ohio

Mosser was a subcontractor to construction manager, Black & Veatch, completing the substructures package for this project. The substructures package included completing 1,200 auger cast piles, 110 drilled piers, and all concrete associated with the project, which amounted to approximately 23,000 cy.

Mosser self-performed all concrete work associated with the project.  This entailed completing underground duct banks, pile caps, slabs, and a large foundation for the equipment associated with the plant. Some of the large concrete work included, Steam Turbine Generator (STG) foundation, two Combustion Turbine (CT 11 and 12) foundations, the two Heat Recovery Steam Generator (HRSG 11 and 12) foundations, the cooling tower foundation, and the main building slab.

  • The STG was the most complex foundation on the project and consisting of many large pours. It had a 5’ thick, 300 cy pour that three condensate cans in the pour. Above and around this STG condensate trench pour was the STG base mat which was also a 5’ thick slab and utilized 650 cy of concrete. On top of the base mat were eight pedestals that were 8’ x 6’ and 30’ tall. To complete these columns, Mosser vibrated the concrete internally and externally to achieve the best finish on them. On top of the eight pedestals was a large 8’ thick table top slab. This was Mosser’s most complex pour on the project as it was elevated nearly 40’ in the air and had a tremendous amount of resteel, embedded plates, and anchor bolts. Mosser used EFCO steel formwork and supports to complete this pour. Last, on top of the table top were six pedestals approximately 5’ tall with a large amount of resteel, embedded plates, and anchor bolts.
  • The CT 11 and 12 foundations included a 720 cy base mat of 5’ thick concrete.
  • The HRSG 11 and 12 foundation included pouring a 700 cy base mat slab that was 2’-6” thick.
  • The cooling tower foundation consisted of constructing a 600’ long foundation that was 65’ wide. This foundation had a large sloped area at one end that was 15’ deep with 21’ tall walls at that end. The remaining foundation had a 1’ thick slab with 6’ tall walls around the perimeter.
  • The main building slab consisted of 49,000 sf of slab that was 1’ thick, with thickened areas around the perimeter.

“The breadth and depth of Mosser Construction’s knowledge and proven execution qualifies them to implement complex projects in a safe manner. I am pleased to recommend them as a subcontractor for future work.”

 Barry Clegg, Black & Veatch, Construction Manager for the Oregon Clean Energy Project