One method of increasing a girder's load capacity while minimizing its web depth is to add haunches at the supported ends. Because of the restrictions incurred in transporting large beams to the construction site, shorter, more manageable lengths are often joined on-site using splice plates. Many modern bridges use new designs developed using computer stress analysis. The rigid frame type has superstructure and substructure which are integrated. Commonly, the legs or the intersection of the leg and deck are a single piece which is riveted to other sections.
Orthotropic beams are modular shapes which resist stress in multiple directions at once.
They vary in cross-section and may be open or closed shapes. Arch types There are several ways to classify arch bridges. A through arch is shown, but this applies to all type of arch bridges. Another method of classification is found in the configuration of the arch. A solid-ribbed arch is commonly constructed using curved girder sections.