Performance of Screw Piles enhanced for lateral load capacity

This paper presents a centrifuge model study of the performance of screw piles with enhanced lateral capacity provided by fins (Screwfin Pile), expanded shafts, or high-level augers. It is proposed that such systems can be made self-installing whereby the screw pile is utilised to embed the fins or other enhancement, and as such the system would be particularly attractive for applications where installation of conventional piles by driving is difficult or unpracticable. The model tests were conducted in a balanced beam geotechnical centrifuge at an acceleration level of 50 gravities in medium to dense uniformly graded dry sand. The installation of the piles was not modelled, and thus only the post-installation performance was assessed. Monotonic lateral loading was applied, and the results are presented through load versus displacement plots, from which lateral capacities are derived. The data set obtained from the tests is compared with a simple analytical approach based on Broms’ method.