ENGEO prepared the geotechnical report for the 5,000-acre solar farm in a sparse valley setting. The project includes photovoltaic solar panel arrays, inverters and transformer equipment pads, and a substation/switchyard. Other improvements include buried electric transmission cables and access roads. Foundations for the solar arrays include shallow driven piles.
With no prior subsurface information in the area, ENGEO developed a phased exploration program to assess the geotechnical conditions associated with three distinct geologic formations. The second phase of exploration was developed to explore critical areas within the three geologic formations and provide information for developing geotechnical design recommendations. Tight schedules required the geotechnical report along with the two phases of exploration to be completed within 4 weeks. Site challenges included characterization of loose sand and mapping of a potential fault-related surface lineament. The geology at the site was mapped by aerial photograph review, field mapping, and subsurface data correlation. Recommendations included LPILE soil parameters for design of the solar array pile foundations.