Pasternak Foundation Model

A two‑parameter elastic foundation model that augments the Winkler (independent‑spring) foundation by adding a shear‑interaction layer; mathematically the foundation reaction q(x) to a transverse deflection w(x) is represented as q = k·w − G·∇^2w (or equivalent), where k is Winkler stiffness and G is the shear coupling parameter, producing lateral coupling between adjacent points of the foundation