The National Steel Bridge Alliance (NSBA) has issued a free resource for Steel Span Weight Curves. The document features design aids that are intended to be used during preliminary phases of bridge design for evaluation of alternative framing schemes. The curves have been constructed from cost-effective conceptual solutions that NSBA has prepared, which represent the predicted pounds of steel per square foot for various span lengths as well as girder spacings for single spans, two spans and three or more spans.
In the document, the weight of steel is represented in terms of square footage of bridge deck because a rough estimate of bridge deck area is typically known in the preliminary stages of design. A total steel weight can be found by multiplying the value obtained from the chart by the total bridge deck area, which the designer or contractor can then use to consult NSBA or a fabricator to obtain pricing for a preliminary estimate of superstructure cost.
To download the document, visit NSBA’s homepage: www.steelbridges.org.