Alexandria Renew Enterprises
This $100 million Nutrient Management Facility (NMF) and Administration Building project includes a 100,000 square-foot Nutrient Management Facility and adjacent 60,000 square-foot office building. The facility allow the wastewater treatment firm to better manage the biological treatment process that helps remove nitrogen from wastewater.
The facility on the west plant site is comprised of an 18-million gallon concrete reservoir extending 30 feet below grade, as well as a Class-A office building with parking below. The new reservoir tanks connect to the existing wastewater plant. Clark also installed a pump station and odor control system, as well as the electrical facilities to power the new equipment, which included relocating existing overhead, high-voltage electrical distribution lines below ground. Clark also constructed a regulation, astro-turf® soccer field above it and installed other related amenities for public use.
Clark Foundations designed and installed the support of excavation, dewatering system, and deep foundations scope of work for the NMF project.The support of excavation design was comprised of both internal and external components working in concert to achieve an overall watertight excavation. The exterior design was comprised of continuously-locked sheet piles that provided groundwater cutoff and allowed the use of traditional cantilevered soldier piles and timber lagging along the interior NMF wet wells and pipe gallery. This design was efficient and economical and resulted in a significant value engineering credit to the owner. Both interior and exterior support of excavation systems included over 1,400 linear feet of driven cantilevered and braced sheet piles ranging between 50 and 65 feet deep, 55 drilled and pressure grouted tiebacks, 132 driven soldier piles, and 8,300 square feet of hardwood timber lagging.
The dewatering scope of work included designing, installing, and maintaining 24 deep wells, groundwater treatment, and localized sumping as needed to effectively dewater the project site without lowering the exterior groundwater elevation. The dewatering systems' design included 12 deep wells along the exterior sheet pile wall and an additional 12 deep wells along the interior soldier pile and lagging wall. Groundwater levels were lowered two to three feet below EL -23 feet to allow for suitable crane benching and placement of the final concrete structure.
Clark Concrete performed concrete work at the connector/garage, which features one-story below ground that is utilized for the parking garage and a roof that will serve as a green area. The structure of both buildings is cast-in-place concrete with a combination of mild reinforcement and post-tension cables.
The Nutrient Management Facility and Administration Building are designed to achieve LEED Platinum certification. The east and west façades feature vertical sunshades to regulate the amount of direct sunlight, allowing for diffused light to enter the facility while preventing excess heat gain.