Publication Details
Abstract
The current study assesses the in-service dynamic performance of three PSC moveable bridges (four main spans, overall length ≈ 66.5 m, width ≈ 9.4 m) located on the Hilla–Kish Expressway, Iraq. IMU/gyroscopic sensors used for controlled vehicle passage field dynamic load testing, baseline (no-traffic) and moving-load records were processed to obtain natural frequency (FFT), traffic-induced vibration frequency, and dynamic displacement (double integration with filtering). A three-dimensional finite element model corresponding to the bridge superstructure was developed in CSI Bridge (ver. 26) in order to produce the same numerical signals at their joints. Agreement was quantified using an efficiency coefficient (experimental/theoretical). Frequency-based results showed (natural: 0.960–0.995; moving-load vibration: 0.936–0.958), indicating Poor agreement, whereas dynamic displacements showed (upward ≈1.084–1.086; downward ≈1.073–1.087). The Poor frequency agreement is attributed to the as-built condition, notably the absence of diaphragms and a pier cap, which typically increase transverse connectivity and stiffness near piers, highlighting the importance of capturing construction details in dynamic field–model validation.