Design aids for simplified nonlinear soil–structure interaction analyses

This manuscript presents the development of charts that structural engineering practitioners can use to quickly quantify the restraining effect at the bases of columns and walls supported on shallow foundations. The formulation is derived based on compatibility, equilibrium, and a simplified constitutive relation that uses two basic parameters to characterize the soil-foundation: the subgrade modulus – the stiffness parameter and the ultimate bearing capacity – the strength parameter. The model captures the intrinsic non-linear behavior of the soil with increasing loading, and the coupling between moments and axial loads. Using the proposed charts, calculated rocking responses for rigid footing models under combined axial load and moment are found to compare reasonably well with experimental results.