Monotonic and Cyclic Axial Full-Scale Testing of Reinforced Helical Pulldown Micropiles

Helical piles are increasingly used to support structures subjected to axial compressive loads. This paper presents the results of full-scale field testing of reinforced helical pulldown micropiles (RG-HSP) installed in clayey soils and resting on sandy soils. The piles were tested under monotonic and one way cyclic axial loadings. It was found that the addition of the reinforced grouted column resulted in a significant increase in the failure load of the pile. Also, during 15 cycles of loading, the piles showed no signs of performance deterioration and experienced minimal increase in displacement. The piles' axial stiffness and capacity were not affected after being subjected to 15 cycles of loading. The experimental results show that the reinforced helical pulldown micropile is a viable deep foundation option for axial monotonic and cyclic loading applications.