Influence of Main Cable Displacement-Controlled Device of Long-Span Suspension Bridge on Seismic Performance of Structure

The main cable displacement-controlled device (DCD) is the key component in coordinating the displacement and the internal force distribution of the continuous suspension bridge. In order to study the influence of DCD on the seismic performance of the structure, a three-span continuous suspension bridge was taken as the engineering background. The influence of different forms of DCD on the displacement and internal force responses of bridge structures under traveling wave action was investigated through numerical simulation. The research results show that different forms of DCD are beneficial in suppressing the displacement and internal force response under earthquakes. Apparent wave velocity and DCD type have an impact on the peak value and occurrence time of each calculated indicator. The improvement of DCD stiffness is beneficial to reducing the amplitude of structural displacement response and tower bottom bending moment response. With the increase of apparent wave velocity, the control effect of DCD on displacement and moment response becomes more obvious. DCD can slightly reduce the shear and torque time history ranges at the tower bottom, but both are not sensitive to the presence of DCD. The form of DCD depends on the topographic factors of the bridge site and the design requirements of related components.