Lateral Performance of Helical Piles Augmented with Collar Vane Technology
Published: 2025
Publication Name: TIDC
Abstract:
This report presents the results of a full-scale experimental investigation of helical pile (HP) foundations augmented with collar vane (CV) technology. The collar vane is a finned element installed near the pile head to mobilize soil resistance at shallow depths and reduce bending demands in slender helical pile shafts. Testing was conducted in cohesive soil and a constructed sand pit and included monotonic and cyclic lateral and torsional loading, as well as overturning tests representative of wind loading on roadside sign structures. Results show that collar vanes significantly increase lateral and torsional geotechnical resistance and reduce shaft bending moments relative to helical piles without vanes. Overturning tests demonstrate that selected HP– CV systems can perform comparably to conventional drilled shaft foundations used for sign support. Overall, the findings indicate that collar vane technology can expand the applicability of helical piles for transportation infrastructure, offering an efficient foundation alternative for infrastructure subjected to lateral loads.