A STUDY ON THE EFFECT OF TOE-WING POSITION ON SCREW PILE PERFORMANCE IN COHESIONLESS SOIL
Keywords:
Toe -Wing Position, Embedment depth ratio (Ed/Ew), Installation Effort, Ultimate Pile CapacityAbstract
Over the past 30 years, screw piles with diverse geometries have gained popularity over conventional piles for deep foundations. The behavior of toe-wing screw piles is not widely recognized on a global scale, and the effect of toe-wing plate position on the performance of screw piles has not been explored. Therefore, this paper investigated the impact of toe-wing position on screw pile performance embedded in the bearing layer. The toe-wing plates were embedded (Ew) in the bearing layer at a depth equal to the wing plate diameter, while the embedment depth (Ed) of the central shaft (pile tip) increased from 0 mm to 90 mm, which reflects the change in the toe-wing position. The model ground was prepared in the steel container with bearing layer densities of 55, 80, and 90 %, while the soil above the bearing layer was placed at a relative density of 45 %. The experimental results indicated that the installation load and torque non-linearly increased with the increase in embedment depth ratio (Ed/Ew). However, if checked at the same embedment depth (Ed), the normalized installation load increased to Ed/Ew = 1.2 and then decreased. In contrast, the normalized installation torque is non-linearly reduced with an increased embedment ratio (Ed/Ew). The normalized ultimate pile capacity increased non-linearly with the increase in embedment ratio (Ed/Ew). Regression equations based on the above trends are presented in this study to quantify the effect of Ed/Ew on installation load, torque, and bearing response.