Comparative analysis of different-shaped interfering footings placed on geocell-reinforced silty sand

The inclusion of geocell in weak soils has emerged as an effective option to enhance its performance. The limitation of suitable land for construction and weaker foundation soils arise the need of interfering footings. The present study investigates the response of circular and square interfering footings of equivalent area placed on geocell-reinforced silty sand. A series of three-dimensional (3D) numerical simulations using finite element approach (FEA) has been performed to evaluate the influence of parameters such as footing-spacing, geometry of geocellgeocell- height and aperture-size, shear strength and stiffness of silty sand on the ultimate bearing capacity (UBC) of interfering footings and the performance comparison thereof. The findings reveal that geocell reinforcement significantly enhances the UBC by improving the confinement and load distribution with comparatively higher UBC values for all the cases of circular interfering footings over the square ones. The UBC improvement for circular interfering footings varies between 12.85-14.68% and 2.35-12.98%, depending on the spacing ratio and geocell configuration respectively. More efficient stress distribution and mobilization of soil resistance for circular interfering footings in addition to uneven stress concentrations at the corners for square footings, may lead to this discrepancy. The study focuses on the importance of providing geocell reinforcement of variable geometry in improving the performance of interfering footings placed on low-stiffness silty sand, with a comparative analysis of different footing shapes. These outcomes provide practical implications for the design of interfering footings on geocell-reinforced silty sand.