Lateral Live Load Distribution in Prestressed Concrete Highway Bridges

Abstract

The design of prestressed concrete highway bridges in the USA is governed by the provisions of the “Standard Specifications for Highway Bridges” of The American Association of State Highway and Transportation Officials (AASHTO) (7). These specifications, or slightly modified versions, have been extensively used in the design of bridges throughout the world (4). The AASHTO Specifications are known to be rather conservative, and in some areas ambiguous. Some, if not most, bridge engineers tend to implement the provisions faith-fully, without due consideration to the first paragraph of the Specifications, which reads “In any case where the specifications provide an empirical formula as a design convenience, a rational analysis based on a theory accepted by the Committee on Bridge Superstructures of the American Association of State Highway and Transportation Officials, with stresses in accordance with the specifications, will be considered as compliance with the Specifications.” The flexibility provided by these statements should be considered by bridge engineers in the review of generally accepted research findings and their implementation in the design of bridges.