Tension Tests on Driven Fin Piles for Support of Solar Panel Arrays

Foundations for small solar installations can have a variety of forms, including cast-in-place concrete, precast concrete, driven piles, and helical screw-piles. A small installation of 70 solar panels was developed to supply power to the Agricultural Experiment Station at the University of Massachusetts. The contractor elected to install driven pipe piles to support the elevated solar panels, however, some questions arose as to the uplift capacity of the piles. In order to resolve the issues, a series of tension tests were performed at the site. In this paper results of tension tests on driven fin piles proposed to support the solar panel arrays are presented. The piles consisted of steel open pipe piles with four fins welded onto the outside to increase the uplift resistance. Three different diameter piles were installed and tested. All piles were driven to a depth of 8 ft. Tests were performed on plain pipe piles without fins and on piles with different configurations of fins in order to provide a comparison of any improvement in tension behavior provided by the fins. The site consisted of an alluvial sandy silt deposit. The results of the site investigation and the pile load tests are presented.