Specified analysis of beams and frames on elastic foundation

摘要

Foundations for 2D and 3D frames are designed very often as continuous footings and a system of interconnected beams, respectively. A continuous footing supporting a 2D frame is shown in fig. 1. The areas of intersection between the columns and foundation are working as absolutely rigid elements like any other area of intersection between the columns and beams of the frame. These elements are usually very large since the sections of the foundation as well as the columns at the first level are also very large. Moreover, in some cases, the columns and/or the footings are enlarged in order to resist the high shear stresses in the foundation that makes the absolutely rigid elements even larger (see fig. 2). Some numerical examples performed by the author confirm that analysis of frames with continuous foundations (that takes into account the absolutely rigid elements) can significantly specify the moments and shear forces in the foundation as well as in the elements of the frame.