Numerical Analysis of Bearing Capacity of Strip Footing Built on Geogrid-Reinforced Sand Slope Over Soft Clay Layer (revised version 3)

Abstract

The paper presents the numerical investigations into the ultimate bearing capacity of the rigid strip footing built on geogrid-reinforced sand over soft clay slope, by means of a detailed parametric study based on a finite element modeling. The parameters investigated are the effect of the vertical distance ratio between consecutive layers (h/B), depth ratio of the topmost layer of geogrid (u/B), number of geogrid layers (N) and the effective depth ratio of reinforcement (H/B), where B is the footing width, and also the effect of friction angle (φ), density of the sand (loose, moderately dense and dense) and the angle of the slope inclination (β). A series of finite element analyses were performed on strip footing using the two-dimensional plane strain model using the computer code Plaxis 2D. The soil was represented by nonlinear Mohr–Coulomb model and Cam clay, which is an elastoplastic hyperbolic stress–strain model, while reinforcement was represented by elastic elements. The results illustrated that by increasing the number of reinforcement sheets and the friction angle, the bearing capacity increased, and by decreasing the slope angle, the depth of reinforcement decreased. The improvement in the bearing capacity of the strip footing on a reinforced slope was found to be strongly dependent on the slope angle and the friction angle of the sand. The best improvement in the bearing capacity was noticed if the spacing between the reinforcement layers (u/B) and (h/B) is small. Numerical results obtained from a series of finite element model tests have been presented and discussed in the paper.