Numerical study on bearing capacity of geocell-reinforced strip footings resting on slopes

Abstract

Most research studies on the behavior of footings on geocell-reinforced slopes were conducted using experimental model tests on small-scale slopes. Very few studies can be found in relation to 3D analyses using detailed geocell structures. It is, therefore, the aim of the present study to investigate this problem by using a 3D finite element analysis. The study begins with verifying the accuracy of the applied finite element method using the results of the experimental model tests on the unreinforced and geocell-reinforced footings on slopes. It continues with studying the effects of main design factors such as the slope angle (β), the depth of the geocell mattress (u), the soil internal friction angle (ϕ), and the footing setback (a) on the bearing capacity of the geocell-reinforced footings. Numerical results suggest that an increase in soil internal friction angle and a decrease in slope angle would both enhance the bearing capacity of unreinforced and reinforced footings. The geocell reinforcement proves to be more effective in improving the bearing capacity of steeper slopes with small friction angles. In addition, the optimum depth of the geocell placement was found to be 0.1 times the footing width (0.1B) regardless of the β and ϕ. Irrespective of the β, the optimum footing setback ratio (a/B) was obtained at 0.5. As a/B ˃ 2, the effect on bearing capacity vanishes. At a constant footing setback ratio (a/B < 2), the use of geocell reinforcement is more effective for steeper slopes. The findings in this numerical study are of practical significance to the geotechnical engineering community.