Lower Bound Limit Design of Rectangular Slabs

A plastic method of design of rectangular slabs based on lower bound solutions of collapse has been developed. The slab is divided into middle and end zones so as to reinforce for beam action in the middle zone and for slab action in the end zones. Earlier developed lower bound limit analysis solutions for rectangular slabs are made compatible with the assumed mode of collapse. Expressions are presented for the plastic moment capacities to be provided in the x and y-directions in the end and middle zones of all the nine possible slab types with combinations of simply supported and fixed edge conditions. Two design illustrations demonstrate the rationale in the application of the method.