Behavior of Nonidentical Differently Loaded Interfering Rough Footings

Abstract

In geotechnical engineering, interference effects caused by the construction of closely spaced footings have a significant influence on the system behavior of each individual footing. As the mutual impact of two footings constructed in close proximity has only been analyzed for identical footings, our aim with this paper is to investigate the interfering effects of closely spaced nonidentical rough footings considering variations of stresses applied to both footings. Therefore, lower and upper bound simulations have been carried out using the finite-element limit analysis (FELA). A validation of the numerical model was accomplished by comparing results for interference effects of identical footings with existing studies in terms of interference factors ξγ. Furthermore, nonidentical footings with equally and differently scaled stresses were studied and corresponding failure mechanisms analyzed. In total, four types of failure mechanisms could be identified in which two mechanisms always compete each other, depending on friction angle, footing widths, spacing, and loading. In contrast to identical footings with combined failure mechanisms, the results show that for nonidentical footings, failure mechanisms most likely develop only below one footing.