Study On Active Control For Continuous Rigid Frame Bridge Under Seismic Traveling Wave Input

In this thesis, the influence rules of seismic traveling wave effect on seismic active control for both of the longitudinally and transversely continuous frame bridge are fully calculated and analyzed direction based on the calculation model of a long-span continuous frame bridge. A series of problems including maximal seismic responses, mean square root and time-displacement history of seismic responses are discussed for the active control of a continuous frame bridge. The main contents and achievements are given as follows.The theory of seismic active control for the long-span frame bridge under ground motion multiple input is established on the basis of active control theory and bridge seismic response calculation theory of ground motion multiple input. Seismic response characteristics of active control under seismic traveling wave incidence are systematically studied for the long-span continuous frame bridge in longitudinal and transverse direction.For the non-controlled longitudinally maximal seismic response of the continuous rigid bridge with high and low piers, the maximal bending moment of piers is at the bottom of the lowest pier, and the maximal moment of beams is on the top of the highest pier. For the non-control transversely maximal seismic response of the continuous frame bridge with high and low piers, the maximal bending moment of piers is at the bottom of the highest pier, and the maximal bending moment of beams is on the top of the lowest pier.The active control can magnify some responses after the bridge is added active devices. At the same time, the seismic traveling effect can give adverse influence on the vibration-suppressed effectiveness of active control for the continuous frame bridge, and the adverse influence for longitudinal control is greater than that for transverse active control.The influence trend of seismic traveling wave effect on non-control is almost as same as that on active for the seismic responses including maximal response, mean square root and time-displacement history curve. The influence of traveling wave effect on non-control and active control increases with the decrement of apparent wave velocity, and the influence has the both trends of increasing and decreasing seismic effect. Seismic traveling wave effect has adverse influence on both of beams and piers for non-control and active control.The seismic response history curve of non-control and active control under traveling wave incidence lags behind that under uniform incidence for some time, and the magnitude of seismic response can also changes.When active control method is used for long-span continuous frame bridge, the calculating and analyzing can be carefully made according to the parameters of the bridge and seismic situation of bridge location, and the reasonable apparent velocity of a traveling wave incidence is selected as an evidence to design the system parameters of active control.