Method for controlling tension of suspenders of longitudinal-double-suspender self-anchored composite-beam suspension bridge

The invention relates to a method for controlling tension of suspenders of a longitudinal-double-suspender self-anchored composite-beam suspension bridge. According to the method, a once-forming construction control stage is defined during the forward mounting of a double suspender model, a cable force in a single suspender model at a staged construction stage is equally distributed to two suspenders, the stress-free length of each suspender at the construction stage is obtained through calculating, and the tension of a suspender tension stage in a staged construction process can be obtained by adopting a stress-free state method by using the stress-free length in a double-suspender forward-mounted model. The method has the advantages that the problem that how to distribute the cable force of the two suspenders during tension is solved; the uniformity of the cable force of the two suspenders at a certain control stage during system conversion and the uniformity of the cable force of the two suspenders at the same suspending point after bridge forming are achieved; through carrying out checking computation on torsion safety of a bracket under the most unfavorable conditions, the structural safety during construction can be guaranteed.