Rigid slab foundation subjected to strike–slip faulting: mechanisms and insights

This paper studies the interaction of rigid slab foundations with a strike–slip fault. A 3D finite element (FE) model of the soil–foundation system is developed, employing a thoroughly validated constitutive model that incorporates strain softening. The widely used rigid box type boundaries are compared to periodic boundaries, demonstrating their superiority. Allowing the soil to deform freely, periodic boundaries allow realistic simulation of fault rupture propagation through soil, and minimization of parasitic boundary effects. An approximate dimensional formulation is presented and verified by comparing the response of two self-similar systems. A parametric study is conducted, revealing two distinct kinematic mechanisms: a rotational one, where the foundation mainly rotates; and a translational one, where the foundation either displaces parallel to the fault trace or remains almost stationary. It is shown that the response is controlled by the presence of the foundation, acting as a kinematic constrain...