Interference of Strip Footings Resting on Nonlinearly Elastic Foundation Bed: A Finite Element Analysis

The study pertains to finite element analysis of two interfering strip footings (symmetrical and asymmetrical with respect to footing size) resting on the surface of a nonlinearly elastic soil (dense/loose sand) medium obeying Duncan and Chang’s hyperbolic constitutive relationship. Predicted pressure–settlement behavior, bearing pressure and settlement characteristics of the interfering footings are then compared with the same for isolated footing, expressing the interference effects in terms of non-dimensional interaction factors. It is found that the characteristic behavior of an isolated footing is greatly influenced due to interference of a nearby footing. Studies have shown that for dense sand, interference affects the response of isolated footing much more compared to loose sand and for asymmetrical footings at very close spacing, the effect is more pronounced for footing with small size. The variation of pressure-interaction factors measured in working/allowable range is found to be similar to that measured at the ultimate failure, but on the contrary, the settlement-interaction factors are found to be different.