CO2 optimization of spread footings using a big bang-big crunch algorithm

A procedure is developed for the design of reinforced concrete footings subjected to uniaxial bending that satisfies both geotechnical limit states and structural requirements using a hybrid big bang-big crunch (BB-BC) algorithm. The objectives are to minimize CO2 emissions and compare designs developed using theoretical analysis procedures with simplified analysis procedures, performed in practice. The CO2 emissions are associated with the extraction and transportation of raw materials; processing, manufacturing, and fabrication of products; and the emissions of equipment involved in the construction process. The CO2 objective function is based on weighted values and is subjected to soil bearing and displacement limits, as well as bending moment, shear force, and reinforcing details specified by the American Concrete Institute (ACI 318-11). A design example is presented to compare low-CO2 emission designs when using the theoretical analysis procedures to low-CO2 emission designs when using simplified analysis procedures, commonly used by practitioners. Results are presented that demonstrate the effects of applied load and eccentricity on designs. © 2014 American Society of Civil Engineers