Iranian Institute of Industrial Engineering Journal of Industrial and Systems Engineering 1735-8272 18 1 2026 01 01 Nonlinear Seismic Modeling of Soil Behavior in Interaction with Foundation for Heavy Structures 1 15 244404 EN Mohammad Aghaei Asl Department of Technology and Engineering, Payame Noor University, Tehran, Iran 0009-0006-1667-6373 Journal Article 2025 06 21 In this research, the nonlinear seismic behavior of the soil–foundation interaction system under heavy structures has been investigated. A numerical model was developed in Abaqus software, where the contact behavior between soil and foundation was simulated considering slippage and shear yielding. To examine the effect of structure mass, analyses were conducted for masses ranging from 200 to 1000 tons under the recorded El Centro earthquake excitation. Output parameters, including horizontal displacement, foundation rotation, interface shear stress, and foundation settlement, were extracted and analyzed as functions of time. The results indicated that as the structure mass increases, the amplitude of horizontal displacement and foundation rotation decreases, while the static settlement and interface shear stress significantly rise. This response stems from the increased effective vertical force and contact pressure beneath the foundation, leading to enhanced frictional resistance and consequently reduced relative movement. The hysteresis loops obtained from the analyses demonstrate considerable energy dissipation at the soil–foundation interface, with greater intensity observed in heavier structures. Ultimately, by performing sensitivity analyses over the mass range of 200 to 1000 tons, power regression relations were derived between seismic responses and structure mass. These relationships can be utilized for rapid estimation of soil–foundation behavior during the preliminary design phases of heavy structures. The findings highlight that incorporating nonlinear soil–structure interaction plays a critical role in realistic prediction of dynamic response and long-term settlement control in the seismic design of deep foundations. https://www.jise.ir/article_244404_d742feafc35038e6887da329f0d9acdf.pdf