Experimental and numerical studies of loaded strip footing resting on reinforced fly ash slope

Abstract

Being a waste material, fly ash can be used in large quantities in construction of highway and railway embankments. This paper presents a series of plane strain model tests carried out on both reinforced and unreinforced fly ash embankment slopes. Laboratory tests were conducted by varying parameters such as embedment ratio, length and number of reinforcement layers, and edge distance from slope crest. A numerical study using finite-element analysis (PLAXIS 2D, version 9.0) was also carried out to verify the model test results. The size of the numerical model was kept the same as that of the laboratory test model. The agreement between observed and computed results was found to be reasonably good. Based on numerical and experimental results, the critical values of the geogrid parameters for maximum reinforcing effects were established

Stability analysis and design charts for a sandy soil slope supporting an embedded strip footing

“…Thus, it can be stated that the maximum e/B , for the surface footing, beyond which the slope has a negligible effect on F is 3. Other researchers [9,29,[35][36][37][38][39][40] who investigated the load bearing pressure of a footing on unreinforced and geosynthetic-reinforced slopes reported a trend comparable to the observation made in the present study. They found that the ultimate bearing capacity of the footing improved with increasing the footing edge distance from the crest.…”

“…As a result, some investigators have validated their works with published numerical data [26][27][28]. Therefore, the validity of the numerical simulations utilized in this study has been verified by using the finite element method to predict the load-settlement behaviour of a footing resting on an unreinforced slope as reported by Gill et al [29] as well as the failure surface and associated factor of safety of a geotextile-reinforced slope from a centrifuge test data reported by Zornberg et al [30,31].…”

“…It assumes the soil stiffness to be constant and for that reason does not take into account the stress nor strain dependency of the soil stiffness during the soil deformation. Figure 3 compares the load-settlement data of the footing from the laboratory experiment [29] and the numerical modelling (present study). It can be observed that the numerical Fig.…”

“…. The fly ash was modelled using the MC model with the strength parameters reported by Gill et al [29]. It should be noted that the MC model, as stated in the previous section, is the first-order of approximation of the behaviour of soil.…”

“…The slope was constructed to a height, H = 750 mm from the base of the tank and an angle, β = 45 • to the base of the tank. A 2-dimensional finite element numerical model was established in this study to represent the load-settlement behaviour of the footing, having a width, B = 100 mm and located at an edge distance, D e to width ratio, D e /B = 1 , on the fly ash slope crest as reported by Gill et al[29]…”