DYNAMIC RESPONSE OF MULTIGIRDER BRIDGES

The objective of the paper is to study the dynamic behavior of multigirder bridges due to vehicles moving across rough bridge decks. The multigirder bridge is modeled as a grillage beam system. The vehicles are simulated as two nonlinear vehicle models with seven and 12 degrees of freedom according to the H20–44 truck and HS20–44 truck design loadings contained in the American Association of State Highway and Transportation Officials (AASHTO) specifications, respectively. The road‐surface roughnesses of the approach roadways and bridge decks are generated from power spectral density function for very good, good, average, and poor roads in accordance with International Organization for Standardization (ISO) specification. A prestressed‐concrete bridge with span of 20 m is designed based on AASHTO standard bridge girders. The dynamic responses of the longitudinal girders are calculated for single truck and two trucks (side by side), with different speeds and road‐surface roughness. The analytical results sh...