Determination of Efficiency Factors for Closely Spaced Strip Footings on Cohesive–Frictional Soils

The bearing capacity of closely spaced footings has become one the important topics in geotechnical engineering research owing to rapid development urban areas around world. In this paper, we propose three efficiency factors that can be used describe effects using Terzaghi’s traditional equation. With an advanced finite-element limit analysis upper and lower bounds, both strip multiple on cohesive–frictional soil with a surcharge effect were investigated. numerical results showed significantly influenced by internal frictional angle spacing ratio. Several comparisons made those published literature. Furthermore, failure mechanisms are presented, while design charts produced wide range practical parameters. This study should great interest foundation practitioners.