CABLE-STAYED BRIDGE VIBRATION DUE TO ROAD SURFACE-ROUGHNESS

The purpose of this paper is to study the dynamic response of a cable-stayed bridge to a vehicle moving across rough bridge decks. The vehicle was simulated by a nonlinear vehicle model with seven degrees of freedom according to the HS20-44 truck. The cable-stayed bridge was modeled as a planar bar system. Road-surface roughness of the approach roadways and bridge decks was generated from power spectral density (PSD) function for very good, good, and averate roads according to International Organization for Standardization (ISO) specifications. The analytical procedure in this study considered geometric nonlinear behavior of the cables, girder, towers, and piers due to dead load. To solve the equations of motion of a bridge with many degrees of freedom, a new numerical procedure for analyzing the dynamic response of a bridge to a moving vehicle is proposed. The impact percentages in the bridge due to the vehicle moving over different classes of roads with various speeds were studied.