Assessment of two nearby interfering strip footings of different embedment depths in saturated cohesive soils

There are instances where foundations are closely spaced, such as around railroad sleepers and foundations close to property lines. In such circumstances, the stress isobars of the separate footings may interact and combine to generate an overlapping stress isobar that affects a wider zone of the foundation soil and alters the individual foundations behavior, which would be different from that of the isolated footings. As a result, an examination of such issues should be conducted by taking into account all the variables that realistically affect the interference behavior of such closely spaced footings. This paper has been conducted to understand the behaviour of closely placed strip footings of different depths embedded in saturated cohesive soils under various factors such as the groundwater table, soil undrained shear strength, footing depth, and the spacing between footings using a three-dimensional finite element model (Midas GTS-NX). The evaluated ultimate bearing capacity (UBC) and settlements are represented in terms of non-dimensional efficiency factors for UBC: ?L/?R (Left/Right). It was concluded that when the spacing between footings is increased from S/B = 1 to 2, there would be an increase in the UBC of both footings when Dfr/Dfl increases, then the bearing capacity decreases when S/B is increased to 4. For footings of different embedment depths, when the ground water table is deep (at 4 m depth), the values of UBC ratio ?R increase with S/B while ?L decreases. This is because of various embedment between the two adjacent footings. In all cases, when the ground water table is at the ground surface, lower values in ?L are at Cu = 60 kPa, while the higher values in ?R are found at this strength.