Minimum Weight Design of Multistory,Multispan Plane Frames Subject to Reaction Constraints

Abstract

This paper presents the necessary and sufficient conditions for the minimum weight design of multistory, multispan plane building frames subject to foundation reaction constraints. It proposes a general, analytical, and explicit constructive law with which exact solutions can be derived for a broad class of frames of practical interest subject to compressive reaction constraints only. It is proved that the classical Foulkes mechanism must be modified for this problem so as to include artificial settlements and/or upward displacements wherever the reactions attain the prescribed limiting values. The bay shear distribution law compactly expressed in terms of the enlarged and reduced span lengths defined in this paper clarifies the general features of the minimum weight design.