Progressive twist, displacement and torsional energy around pile groups

ABSTRACT The progressive twist and displacement in the sand are investigated for a set of pile groups (1,2; 1,3; 2,2) corresponding to the application of the torsional loads. A novel numerical model supported by a set of experimental observations has been considered to capture pile-soil interaction for the pile groups subjected to torsional load. The torque mobilization, progressive twist, and displacement have been computed for a range of the initial shear modulus ratio for the entire set of pile groups. As a result of twisting, the torsional energy zones are set into the soil, and there is the formation of a heave and cavity around the pile group. The torsional energy and twist rigidity parameters were evaluated for a range of shear modulus ratios of the soil. It has been observed that the torsional energy of the pile group (1,2) is significantly higher than pile groups (1,3; 2,2). A classification for torsional energy zones associated with twist rigidity and displacement rigidity factor has been suggested to set the limits for twist and displacement of the pile groups relative to a single pile. A relationship of the torsional energy with progressive twist and displacement is obtained. The components of torsional energy associated with progressive twist and displacement were obtained in the range of 0.43–0.50 and 0.50–0.57 respectively Graphical abstract