Assessment of interaction mechanism and bearing capacity of strip footings located on slope face

Abstract

Construction of residential and commercial buildings on the slope face is very commonly noted in the North-eastern and other mountainous terrains of India. Closely spaced buildings and the foundation elements located on such slope faces interact with each other, thereby influencing the stability of the slopes, which, in turn, affects the failure mechanism and bearing capacity estimation of such foundation systems. Several literatures are available highlighting the response of foundation located on the slope crest, while those elucidating the response of foundation located directly on the slope face are scanty. Among them, there are extremely few literatures available showcasing the interaction of footings located on slope face. Hence, considering the practical importance of the issue, this paper reports a numerical two-dimensional finite element-based study that is conducted to determine the failure mechanism and bearing capacity of interfering strip footings located on the face of a slope. The study aptly demonstrates that the response of interfering footings is governed by the soil type, footing width, slope inclination, and the relative elevation between the footings. It is observed that upon increasing the footing width by two times, the bearing capacity of interfering footing increases by 33%, even though the interfering mechanism remains the same. It was also noted that with each successive increase in the slope inclination by 5°, the interfering bearing capacity gets reduced by 37 %. Under any parametric circumstances, maximum interference between the strip footings is noted when their relative height of separation (in terms of footing width) remains close to 2, while the interference is found to be completely disappearing when the relative height of separation is 8 or more. This finding should aid in the decision making about the proper choice of inclusion of interference effect during the analysis and design of foundations on slope face.