Buckling of Linear Structures above the Surface and/or Underground

A particular method for determining the critical load of linear structures partially or totally located in different elastic media is presented. It can be used to calculate the buckling load of pile–columns (columns partially embedded in soil), for instance. The buried part of the linear structure could pass through different soil layers, and the whole structure could be restrained at any point. The algorithm proposed is based on the fact that the stiffness matrix of an element in an elastic medium depends on the axial load exerted on that element. Therefore, when the axial load becomes critical from the point of view of the element’s stability, the corresponding flexibility matrix tends to infinity. Above-ground structures are assumed to be in an elastic medium with a very low coefficient of reaction. The paper describes the method in detail through different examples, and provides the flowchart of the algorithm used for the iterative calculations.