Experimental Study on Configuration and Spacing of Screw Pile Group Effect Subjected to Lateral Cyclic Loading

Abstract

Despite the great development in the manufacture of the helical pile and the development of their use, especially in transmission towers and wind turbines, there is little research on their lateral behavior. In this laboratory study investigate the behavior of screw piles group (2×1) and (1×2) with the spacing to the diameter of helix ratio (S/Dh =1.5, 3, and 4.5) having a diameter (10 mm) and embedded length to diameter ratio (L/D = 40) by using single and double helix embedded in soft clay and extend to stiff clay under a cyclic lateral load of frequency (0.2 Hz). The results showed that increasing the distance between the piles had a great effect on increasing the lateral resistance. the increase of pile spacing in the groups from (1.5 Dh) to (3 and 4.5 Dh) increases the lateral resistance about 34-38% and 50% respectively. Also, from result showed that the group (2×1) gave a lateral resistance more than the group (1×2) about 11% for single helix and about 6% for a double helix, and for the same spacing and configuration the screw pile with double helix gives an increase in lateral resistance about 5-10 % from the single helix.