Fundamental study on the design method of steel truss bridge by structural optimization using reused members

Abstract

A design method for steel truss bridges using reused members was proposed and evaluated in this study. It consisted of shape and size optimization, with the objective function being steel weight, carbon dioxide emissions, and cost. The case studies showed that the use of reused members led to a reduction in CO2 emissions and lower cost than using new members when the stock of reused members was plentiful. However, when the stock of reused members was not sufficient, the balance between steel weight/cost and CO2 emissions became important. The results of using a weighting factor for the objective function showed that there were only a few discrete structurally reasonable solutions with different reuse rates. This indicates that there is a balancing relationship between the three objectives.