Optimizing long-span girders can save scares resources. The following are a few conceptual options to optimize girders. Optimization for a real project requires careful evaluation of alternate options, considering interdisciplinary aspects along with purely structural ones.
1 Moment diagram, stepped to reflect required resistance along girder
2 Steel girder with plates welded on top of flanges for increased resistance
3 Steel girder with plates welded below flanges for increased resistance
4 Reinforced concrete girder with reinforcing bars staggered as required
5 Girder of parabolic shape, following the bending moment distribution
1 Girder of tapered shape, approximating bending moment distribution