Two CNC Foundations drilling rigs in operation on a muddy construction site, with one auger actively drilling into the ground to install foundation support for wind turbines under clear blue skies.
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A CNC Foundations pickup truck stationed between two heavy excavators working on foundation drilling, surrounded by flat farmland and blue skies—part of settlement control work for wind turbine infrastructure.
A large yellow CNC Foundations excavator being transported on a flatbed trailer down a gravel path, with crew members and company vehicles visible in the background, on a wind farm site in rural Arkansas.

SETTLEMENT CONTROL SOLUTIONS FOR WIND TURBINE FOUNDATIONS IN CROSS COUNTRY, ARKANSAS

  • Cross County, Arkansas

CNC Foundations (CNC) delivered ground improvement services for the construction of 18 wind turbines at the Crossover Wind Farm: the first wind energy project in Arkansas. Developed by Cordelio Power and fully operational in 2025, the 135-MW facility features 33 Vestas V163-4.5 MW turbines, generating enough renewable energy to power approximately 50,000 homes.

Beyond renewable energy generation, the project strengthens the regional economy through property tax revenue and long-term land lease payments to local farmers. CNC’s aggregate pier ground improvement solution enhanced bearing capacity, minimized settlement, and reduced liquefaction potential, allowing turbine foundations to be installed across active agricultural terrain while preserving farmland usability during and after construction – a crucial factor in balancing infrastructure development with ongoing farming operations.

Project Details

  • Owner: Cordelio Power
  • General Contractor: Mortenson
  • Structural Engineer: BARR Engineering Co
  • Turbine Count: 18
  • Install Numbers: 1,950+ aggregate piers at over 55,000 linear feet
  • Design Bearing Capacity: 1,500 psf
  • Service: aggregate Piers – vibratory stone columns

The foundation system had to support large, high-load turbine foundations across a wide site characterized by variable, compressible soils. With strict performance limits and a fast-moving construction schedule, CNC Foundations was tasked with delivering a cost-effective, repeatable, and scalable solution that could adapt to each turbine location.

The geographic scale of the project introduced logistical challenges, requiring meticulous planning, field coordination, and sequencing to keep installation continuous across multiple active work zones – all while maintaining alignment with Mortenson’s broader construction timeline.

Subsurface conditions included:

  • Topsoil: 6 to 12 inches thick
  • Silt & Clay Layers: Up to 15 feet deep 
  • Sand Layers: Extended to depths of 40 to 50 feet, 

These conditions required a solution capable of transferring loads into deeper, more competent strata while improving the composite stiffness of the upper soils.

CNC Foundations installed over 1,960 aggregate piers across the turbine foundations, totaling over 55,000 linear feet. Each column was constructed using a vibratory flot that placed and compacted stone in successive lifts from the target depth up to final grade. This installation approach produced stiff aggregate elements that:

  • Improved bearing capacity of the underlying soils

  • Controlled settlement within specified performance limits
  • Reduce risks of liquefaction during as seismic event

  • Streamlined installation across numerous turbine locations

  • Eliminated the need for deep foundation systems 

Completed on budget and ahead of schedule, CNCs execution helped bring Arkansas’s first wind farm online, demonstrating how engineered ground improvement supports both infrastructure innovation and sustainable energy expansion.