Large-Scale Laboratory Testing of Helical Piles: Effect of the Shape

Publication Name

Geotechnical and Geological Engineering


In this study, a large-scale laboratory testing apparatus was developed to investigate the effect of different helical shapes on the helical pile installation and the axial compression loading bearing pressure. The various helical shapes were designed using 3D printing technology. The high strength Polylactic acid Plus (PLA-Plus) material was used for printing different helical shapes. The helical pile’s installation was accomplished by coupling the shaft of the helical pile to a torque engine that rotates the helical pile in the soil. After installing the pile to a predetermined depth, compression loading tests were conducted on helical piles under a constant strain rate. The results illustrate that the helix shape has a significant influence on the performance of the helical pile. The multi-pitch helix produces an 18% increase in bearing pressure compared to the traditional helix. The helix diameter has exhibited a significant influence on the helical pile bearing pressure. Moreover, an empirical equation was proposed to estimate the coefficient of torque (Kt) using the helical pile embedment area for measuring the bearing capacity and installation torque of the helical pile.

Open Access Status

This publication is not available as open access

Funding Sponsor

University of Wollongong



Link to publisher version (DOI)