Dynamic Behaviour of Re-entrant Corner Buildings Considering Soil-structure Interaction

Abstract

Re-entrant corner buildings, widely used in contemporary architectural design, possess inherent torsional irregularities that make them particularly susceptible to seismic forces. When soil-structure interaction (SSI) is introduced, the seismic behaviour of these buildings becomes even more complex due to the combined effects of soil flexibility and plan discontinuity. This study examines the influence of SSI on the dynamic behaviour of re-entrant corner buildings by analysing their seismic response across varying geometric configurations. A comprehensive literature review was carried out to understand existing research on torsional irregularities, SSI, and seismic performance, revealing a significant lack of studies that integrate re-entrant corner severity with soil flexibility. Building frames with an A/L ratio of 0.8 are modelled as per IS 1893:2016 under both fixed-base and SSI conditions. The response spectrum method was employed to evaluate critical seismic response parameters, including the fundamental time period, storey stiffness, storey shear, and lateral displacement. The findings indicate that SSI considerably alters the seismic behaviour of all building configurations by increasing structural flexibility, amplifying lateral deformation, and reducing overall stiffness. These adverse effects intensify as the A/L ratio decreases, indicating that slender re-entrant corner buildings experience the greatest deterioration in seismic performance under SSI conditions. The study underscores the necessity for enhanced lateral load-resisting systems in such buildings to ensure safe and reliable behaviour during seismic events.