Soil-Structure Interaction-Based Comparative Analysis of Footing Types for Tall Reinforced Concrete Buildings: A Comprehensive Review of Winkler Spring Models, Seismic Performance, and Foundation Design Optimisation

The seismic design of tall reinforced concrete (RC) buildings requires explicit consideration of soil-structure interaction (SSI), which governs the dynamic characteristics, load distribution, and settlement behaviour of the foundation system. Conventional design practice frequently neglects SSI through the rigid-base assumption, potentially yielding unconservative estimates of footing demand. The plan geometry of isolated footings directly controls the SSI interface stiffness, contact pressure distribution, and Winkler spring response under combined gravity and seismic loading. This review synthesises four decades of theoretical, experimental, and computational research on SSI-based footing behaviour for tall buildings, with particular focus on the comparative performance of rectangular, square, oval, and elliptical isolated footings. To consolidate and critically evaluate published research on SSI modelling approaches for shallow foundations; to review comparative FEM-based studies of footing geometry effects on SSI-mediated structural response using STAAD.Pro and equivalent platforms; and to identify the most SSI-compatible footing geometry for tall RC buildings under Indian seismic conditions, with respect to shear force, axial force, support reaction uniformity, deflection, and construction cost. Oval and elliptical isolated footings consistently exhibit superior SSI performance relative to conventional rectangular and square profiles. The smooth curved perimeter eliminates corner Winkler spring concentrations, producing more uniform contact pressure distributions and lower peak structural demands. SSI-inclusive FEM analyses report reductions of 84-95% in maximum shear force, 83-90% in peak support reaction, 89% in axial force, and approximately 49% in maximum footing deflection for oval footings versus rectangular equivalents under seismic loading. Reinforcement savings of 15-17% yield proportional cost reductions. Advanced SSI modelling (Pasternak, continuum FEM) and machine learning integration are emerging research frontiers. Priority directions include nonlinear SSI analysis with plastic soil yielding, experimental V-H-M validation of oval footings, taller building (G+10 to G+20) and higher seismic zone (III-V) parametric studies, two-parameter Pasternak SSI modelling, and development of codal design provisions for non-conventional footing geometries.