Research On Seismic Vibration Control Of Huge Platforms With Upper Structures

Through theoretic analysis and computer simulation, the seismic vibration control of huge subway platforms with upper structures is discussed in this paper.First, based on characteristic of structure, the departments above the shock absorption devices are simplified as a single mass point unit, and the below structures are also considered to be an equivalent structural unit. Thus the structure system is simplified a two-degree (not consider the mass of absorption devices) or three-degree (absorption devices' mass is considered) vibration system. After the mechanical model and the dynamic differential equations of the buildings are set up and solved using the theory of structure dynamics, the base isolated system, the TMD system, and this up-low control system are discussed. The analysis results show that the stiffness and damp of the superstructure are variables that play important parts in the effects of earthquake response's decreasing.Secondly, finite element models are established to analysis the mechanical performance of BAWANGFEN subway platform with upper two buildings in Beijing. The response of earthquake time history analysis between the vibration control structure and no control structure system are compared. The results indicate that the interlayer shear forces and the interlayer displacements of the upper building and the platform are far lower than the response of the no control system under the same condition of the superstructure. It is also indicated that the dynamical response of no vibration control building on platform is increased while the other building is controlled.According to the different responses under different earthquake records, this paper studied the long-period character of this kind of vibration control structure also.