ABSTRACT
The tensioning operation of a tied-arch bridge is mainly divided into two steps: initial tensioning and secondary cable force adjustment, where the latter is difficult due to the interaction between suspenders and the adjustment amount of cable force. In this study, the thinking method of the one-off tensioning construction control for tied-arch bridges was introduced. With a 30+130+30 m fly-bird-type tied-arch bridge taken as an example, the one-off suspender tensioning construction control was explored. In the theoretical calculation phase, the deviation and precision control criteria for cable force were proposed, and fast convergence was achieved in the iterative computations by taking the initial tensile force approximate to the dead weight of the midspan steel box girder. In the completed bridge phase, the suspenders with the over-ranging deviation of the measured cable force from the target cable force of the completed bridge accounted for about 11%. In the suspender tensioning process, the temporary loads on the bridge deck would change the unstressed length of the suspenders, which was the primary cause for the deviation of cable force. However, the cable forces of all suspenders met the requirements through local fine adjustment. Therefore, the overall one-off tensioning control effect of suspenders was satisfying, thus providing a reference for similar structures.
