Geomechanical Modeling of Yield Surface Engineering in Sands to Optimize Nonlinear Seismic Response of Soil–Structure Systems

Abstract The nonlinear seismic behavior of soil–structure systems is critically influenced by the onset and evolution of plasticity in underlying sands. This study introduces a novel framework for engineering the shape and evolution of yield surfaces in granular soils to improve seismic performance metrics such as residual displacements, foundation uplift control, and energy dissipation. A geomechanical constitutive model is developed that enables manipulation of yield surface geometry and kinematics under dynamic loading conditions. By integrating controlled hardening mechanisms and directional plastic flow rules, the model is capable of tailoring soil response to better accommodate cyclic seismic demands. The framework is implemented within a finite element environment and validated against benchmark shaking table tests and numerical simulations. Results demonstrate that yield surface engineering can significantly reduce permanent deformations and enhance the resilience of soil–foundation systems without the need for external reinforcements. The proposed approach provides a new direction in the performance-based seismic design of geotechnical systems, with potential applications in foundation optimization and liquefaction-resistant soil improvement strategies.