Two CNC Foundations rigs and a service truck onsite at SunZia Wind Farm, performing deep foundation work including aggregate pier drilling to stabilize soil beneath wind turbine foundations.
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CNC Foundations team operating dual rigs to drill and backfill aggregate piers as part of a large-scale ground improvement project at SunZia Wind Farm in wide open desert terrain.
CNC Foundations installing aggregate piers at SunZia Wind Farm using CAT excavators, with gravel piles in the background—part of a subsurface stabilization effort supporting wind turbine foundations in New Mexico.
A CNC Foundations rig equipped with a vibratory compaction tool stands under a dramatic cloud-filled sky at SunZia Wind Farm during aggregate pier ground improvement for wind turbine infrastructure.

SUBSURFACE STABILIZATION SUPPORTING TURBINE FOUNDATIONS AT SUNZIA WIND FARM

  • Corona, New Mexico

CNC Foundations (CNC) supported the landmark SunZia Wind Project in New Mexico with ground improvement services using vibratory stone columns. While CNC Foundation’s scope consisted of over 175 aggregate piers totaling over 1,300 linear feet, this work contributed to one of the most significant renewable energy developments in North America.

Developed by Pattern Energy, the SunZia project features over 900 GE Vernova and Vestas turbines, along with a 550-mile, 525 kV HVDC transmission line that delivers clean energy to Arizona and California. Once fully operational, SunZia is expected to generate 3.5 gigawatts of power, support 3 million homes, create over 2,000 construction jobs, and drive $20.5 billion in economic impact across New Mexico and Arizona.

CNC’s solution provided crucial stability in geologically sensitive terrain, supporting the reliable rollout of this historic renewable energy infrastructure.

  • Owner: Pattern Energy Group LP
  • General Contractor: Blattner Energy Inc.
  • Structural Engineer: RRC Power & Energy
  • Project Timeline: 2 Production Days
  • Install Numbers: 190 aggregate piers at over 1,300 linear feet
  • Design Bearing Capacity: 4,000 psf
  • Service: Aggregate Piers – Vibratory Stone Column
  • Market Sector: Wind Farm
  • Project Scale: Over 1,000 turbines across two counties

The project required a foundation system capable of supporting wind turbine loads in an area characterized by collapsible soil layers, variable shallow bedrock. These conditions introduced risks of void migration, differential settlement, and inconsistent bearing performance across the site. CNC Foundations was tasked with delivering a stable, uniform, rapid-installation solution that could adapt to these geotechnical extremes while keeping pace with the broader construction schedule of this massive renewable energy initiative.

Subsurface investigation identified several challenges requiring targeted ground improvement:

  • Weak Near-Surface Soils: Collapsible soils, soft clays, and loose sands reduced bearing capacity across upper layers.

  • Shallow Hard Rock Zones: Hard bedrock at variable shallow depths complicated consistent foundation design.

These variable and high-risk conditions necessitated a ground improvement system capable of delivering uniform support, mitigating settlement, and adapting to localized geotechnical extremes across the site.

CNC Foundations installed 190 aggregate piers to improve subsurface performance. Using a vibratory flot, stone was placed and compacted in vertical lifts from design depth to grade, forming dense aggregate piers that:

  • Increased allowable bearing capacity
  • Controlled settlement within tight tolerances
  • Delivered reliable support in karst-prone and collapsible soils
  • Enabled fast, low-disruption installation across the site

The work was completed in just helping maintain alignment with the broader construction schedule for this multi-billion-dollar renewable energy initiative.