In this paper, the influence of longitudinal stabilizing cables on the modal and dynamic response characteristics of the cable-stayed Ting Kau Bridge is studied based on a calibrated three-dimensional finite element model. A hybrid-element cable system is adopted in the model in which all the eight longitudinal stabilizing cables are modeled by multi-element cable system taking into account the sag and tension effect (geometric stiffness) while other cables are modeled by single-element system. The dynamic characteristics of the bridge are then evaluated for the cases with all eight longitudinal stabilizing cables, with only fewer longitudinal stabilizing cables, and without any longitudinal stabilizing cable respectively. It is found that the longitudinal stabilizing cables greatly influence the global dynamic characteristics of the bridge: (l) The natural frequency of the first global mode of the bridge increases from 0.141 Hz to 0.163Hz after installing the eight longitudinal stabilizing cables; (2) The stabilizing cables result in some global modes with strong modal interaction among the deck, lowers and cables; (3) The stabilizing cables participate significantly in modal motion of certain global modes, leading to the change of the modal participation factors in dynamic response evaluation
