Simplified Dynamic Analysis of Barge Collision for Bridge Design

The AASHTO design provisions for barge impact on bridges spanning navigable waterways use a static force approach to determine structural demand on bridge piers. Recently, however, full-scale experimental dynamic tests of barge impact have indicated that consideration should also be given to additional forces generated from dynamic effects. Specifically, mass-related inertial forces generated by the superstructure of a bridge can restrain underlying pier columns and lead to dynamic amplification of column design forces. This paper presents an algorithm for performing simplified, coupled dynamic barge impact analysis for bridge structures. This type of analysis yields structural design forces, with dynamic amplifications included, on the basis of characteristics of the design impact condition (barge mass and speed). Results from the proposed simplified analysis method are validated using full-scale experimental test data and are compared with results obtained from full-resolution analyses for a variety of barge impact energies and bridge types.