Minimization of Cost and CO2 Emissions for Rectangular Spread Footings Subjected to Biaxial Loading

A Big Bang-Big Crunch (BB-BC) optimization algorithm was applied to the analysis and design of reinforced concrete spread footings subjected to concentric, uniaxial, and biaxial loading. For spread footings subjected to eccentric loading conditions, it is convenient to assume that the entire base of the footing remains in contact with the soil, resulting in a compressive bearing pressure distribution. However, this assumption does not accurately describe the nature of the bearing pressure distribution. Analysis procedures for spread footings subjected to eccentric loading conditions that allow uniaxial and biaxial uplift were developed. From these formulations, an analysis chart of the bearing pressure surface equations for one, two, and three footing corners detached was developed to determine percentages of detachment along the edges of a spread footing that is subjected to biaxial uplift. In addition to assuming that the entire footing base remains in compression, it is common to make several other simplifying assumptions when designing spread footings subjected to uniaxial and biaxial loading. A BB-BC optimization algorithm is applied in order to compare spread footing designs based upon theoretical analysis procedures and designs based upon simplifying assumptions. Since cost has always been an integral part of engineering design and CO2 emissions are becoming of greater concern, a multi-objective optimization was utilized to develop relationships between cost and CO2 emission associated with the design of reinforced spread footings subjected to concentric, uniaxial, and biaxial loading