Soil-Structure Interaction for Building Structures - Chapter 2 :Inertial Interaction Inertial interaction refers to displacements and rotations at the foundation level of a structure that result from inertia-driven forces such as base shear and moment. This chapter describes inertial soil-structure interaction effects. Inertial displacements and rotations can be a significant source of flexibility and energy dissipation in the soilstructure system. Section 2.1 discusses system behavior and highlights some of the principal effects of inertial interaction and the conditions for which its effects are significant. The methods focus on single degree-of-freedom systems, but they can be extrapolated to multi-degree-of-freedom systems with a dominant first mode. Section 2.2 provides a relatively detailed description of how foundation springs and dashpots can be specified to represent the flexibility and damping associated with soil-foundation interaction in translational and rotational vibrat ...