The current American Association of State Highway Traffic Organizations (AASHTO) Guide Specification for Collision Design of Highway Bridges provides three statistical methods(methods I, II, and III) for determining the design vessel for impact analysis. These methods focus mainly on ship impact and not on barge impact design for bridges susceptible to vessel (ship or barge) impact. This is due to the tremendous variation in flotilla sizes, barge types, and barge sizes. This study presents an analysis procedure by which the statistical design methods of the AASHTO Guide Specification can be applied to inland waterway bridge design.

Design of bridges susceptible to barge impact using either AASHTO Method I or II is simplified through the use of the "equivalent static load" representation of the dynamic interaction of the barge-pier collision. However, the equivalent staticload method neglects the dynamic interaction between the individual barges in the flotilla and the bridge during the collision. Three dynamic analysis procedures are presented herein as suggested revisions to the current AASHTO equivalent static load method. The procedures are: Psuedo-Dynamic Analysis Procedure (PDAP); Impact Spectrum Analysis Procedure (ISAP); and Time History Analysis Procedure (THAP).

The results of this study makes possible true dynamic analysis and design of bridges susceptible to barge traffic. True dynamic analysis includes member loads that result from the inertial effects of the loading.

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