Stability Analysis of Geocell-Reinforced Slopes Using the Limit Equilibrium Horizontal Slice Method

Given the three-dimensional confinement, the geocell reinforcement can act as a beam that can carry both bending and membrane stresses compared with only the planar membrane effect of planar reinforcement. This study presents an analytical approach to determine the factor of safety (FOS) of geocell-reinforced slope using the horizontal slice method (HSM). The geocell reinforcement composed of geocell and infill soil was modeled as a composite beam filled with soil. The improvement in the FOS of the geocell-reinforced slope was expressed in terms of vertical stress dispersion, vertical frictional resistance, and structural mechanisms provided by geocell reinforcement. The effect of geocell pocket diameter on the soil confinement and FOS of geocell-reinforced slope was considered using hoop tension theory. The results of the proposed analytical model were compared with those determined by numerical modeling using the strength reduction method (SRM). A series of parametric analyses were also performed to evaluate the influence of the placement depth of the geocell layer, the number of geocell layers, the pocket diameter and the height of geocell, and the slope angle and soil shear strength, on the stability of the geocell-reinforced slope. The results indicate that the reinforcing mechanism of geocell reinforcement is considerably related to the geocell thickness. The mobilized flexural strength and vertical frictional resistance magnify as the height of the geocell increases. Compared with planar reinforcement, a smaller quantity of geocell reinforcement is required to achieve an equivalent FOS value. The results predicted from the present analytical approach were found to be in good agreement with SRM results. (C) 2017 American Society of Civil Engineers.