Influence of installation method on performance of screwed pile and evaluation of pulling resistance

Abstract In the present study, we performed installation and pull-out loading tests on screwed piles in sand deposits using a calibration chamber. These tests focused on how the installation method influenced the performance of the piles. The results revealed that the load-displacement relationship strongly depended on the installation method, but that the second-limit uplift resistance was almost unaffected. Next, we observed the movement of the soil near the pile after both the installation and pull-out loading tests. Shear failure of the soil, which occurs in a cylindrical region in the periphery through which the wing plate of the pile passes, regardless of how the screwed pile is installed, was found to be one of the determinants of the pulling resistance. Finally, we evaluated the pulling resistance of the screwed pile based on these soil observations and an analysis of the loading test results. We found that the pulling resistance of the wing plate could be determined based on the change in earth pressure near the pile due to installation and pull-out loading of the pile.