Experimental and Numerical Investigations on the Bearing Capacity of Footings on the Layered Soil

Model footing tests were conducted on two types of footings having aspect ratio (L/B) equals to 1, and 2 resting on single and two layered soil with a geogrid layer placed at the interface of two layered soil. The effect of the upper soft clayey layer stabilized with molasses, waste foundry sand, and lime over medium dense sand was studied by varying the thickness ratio (h/B) of upper layer (h/B = 0.8, 1.2, 1.6, 2.0). The reinforcement effect was investigated by adding geogrid layer of varying width ratio (b/B = 0, 2, 3, 4) at the interface between upper soft/stabilized clayey layer and lower medium dense sand layer. In order to validate the results of the model plate load tests, the bearing capacity behaviour of footings with aspect ratios (L/B) of 1 and 2 was calculated using the finite element method (FEM)-based ABAQUS software. The results of model plate load tests shows that the ultimate bearing capacity of square and rectangular shaped footings at h/B = 1.6 and b/B = 3 was optimum when compared to other thickness ratios (h/B) and width ratios (b/B). This is because the above soft clayey soil was stabilised with optimum amount of additives and placement of a geogrid layer at the interface. Further, upon comparing the pressure settlement behaviour curves generated using model plate load tests and ABAQUS software, a close agreement was found, with numerical results rising slightly upwards.