Abstract
Vehicle load may not only cause vertical deformation and vibration of suspension bridge but also lead to longitudinal deformation and vibration. And the longitudinal behavior is closely related to the durability of the girder end devices and the bending fatigue failure of suspenders. In this study, the longitudinal deformation behavior and longitudinal vibration of suspension bridge under vehicles, as well as the related influencing factors, are investigated. The underlying mechanism of girder longitudinal movement under the moving vehicles is revealed. Based on the simplified vehicle model of vertical concentrated force, the characteristics of main cable deformation and girder longitudinal displacement under vertical loads are analyzed first. Then, the longitudinal motion equation of the girder under vertical moving loads is derived. Finally, a single long‐span suspension bridge is employed in the case study, and the girder longitudinal response and influencing factors are investigated based on both numerical simulation and field monitoring. Results indicate that the asymmetric vertical load leads to cable longitudinal deflection owing to the geometrically nonlinear characteristic of the main cable, leading to longitudinal movement of the girder. The results of field monitoring and numerical simulation indicate that the girder moves quasi‐statically and reciprocates longitudinally with centimeter amplitude under normal operational loads.
Highlights
Vehicle load may cause vertical deformation and vibration of suspension bridge and lead to longitudinal deformation and vibration
Such bridges are flexible and vibration sensitive, and the stiffness and vibration of the suspension bridges are major topics in research on structural dynamics. e previous studies showed that the fatigue and durability of girder end ancillary facilities such as the expansion joints, dampers, and bearing are related to the reciprocating longitudinal movement characteristics of the stiffening girders. e huge accumulative displacement caused by traffic or wind loads during the operational stage is an important reason for the damage of the end attached facilities [2,3,4,5]. e reciprocating longitudinal movement may induce fatigue failure of short suspenders for suspension bridge [6,7,8,9] and oil leakage of hydraulic damper [10]
An increasing number of investigators are paying attention to the issues of girder longitudinal movement and its factors under vehicle load for the suspension bridge at present, owing to increasing cases that the girder end devices fail prematurely due to operational actions. e vehiclegirder longitudinal movement relationship is mainly investigated qualitatively via statistical regression based on bridge health monitoring data [21,22,23,24,25], or numerical analysis based on finite element (FE) [26,27,28]
Summary
E steel truss girder with a total length of 1000.5 m is adopted for the bridge stiffening girder, which consists of main trusses, top and bottom bracings, and transverse trusses. E girder end displacement monitoring system was installed on the Aizhai Bridge and began operation on February 25, 2016, to clearly understand the longitudinal behavior of the suspension bridge during normal operation period. A total of 10 sensors including four ultrasonic displacement sensors, four draw-wire displacement sensors, and two temperature sensors were installed to monitor the stiffening girder longitudinal movement and structural temperature.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
