Limit Analysis of Flat-Slab Buildings for Lateral Loads

The strength of unbraced, multistory, flat-slab buildings subjected to a combination of gravity and lateral loads can be investigated by limit analysis methods. A particularly useful method for analyzing the flexural strength of the slab and of the slab-column joints is the yield-line theory. From such an analysis it is also possible to obtain the limiting moments for which the columns must be designed in order to assure that at the collapse load all yielding will take place in the ductile slabs rather than in the more brittle columns. In what follows equations will be derived to permit the analysis of such a structure and graphs will be presented to facilitate a design for the combined loading.