Static characteristic analysis of high-speed railway suspension bridge with kilometer span

In order to accurately grasp the mechanical characteristics of high-speed railway suspension bridge under static load, combined with field test and finite element model, taking Wufengshan Yangtze River Bridge with a span of 1 092 m as the engineering background, the structural mechanical behavior of super-long-span steel truss girder suspension bridge under static load was studied. The variation characteristics of steel truss girder and main tower stress, main cable strand force, bridge deflection, beam end rotation angle, main tower, bearing and beam end longitudinal displacement, sling cable force under different loading conditions were revealed. The static characteristics of suspension bridge were comprehensively analyzed. The results show that under different loading conditions, the forces on the upstream and downstream chords are uniform. The forces on the upstream and downstream inclined rods change greatly. The force change of the main tower is small, and the ratio of the measured value to the theoretical value is between 0.70 and 0.94. The stress of each strand of the main cable is uniform. The stress changes of the upstream and downstream side strands are consistent. The overall mechanical performance of the main cable is good. The measured deflection-span ratio of the bridge is 1/530, which is less than the design deflection ratio 1/487. The measured maximum rotation angle at the beam end is 0.56‰rad. The vertical stiffness of the bridge is large and meets the relevant requirements. The longitudinal displacement of the bearing changes evenly, but it is affected by the longitudinal friction resistance of the bearing and the damper at the initial stage of operation. When the load is large, the longitudinal displacement changes slowly, so that the theoretical value is greater than the measured value. The displacement of the beam end is consistent with the displacement of the bearing, and the longitudinal displacement of the bridge changes evenly. The longitudinal displacement of the main tower top and sling force change evenly, and the measured values are in good agreement with the theoretical values. The research results can not only provide reference for the design of similar bridges, but also provide “fingerprint” information for the later operation and maintenance of bridges. © 2023, Central South University Press. All rights reserved.