Development of locally resonant meta-basement for seismic induced vibration control of high-rise buildings

High-rise buildings may suffer severe damage or even collapse when subjected to excessive vibrations during earthquake excitations. Suppressing seismic induced vibrations is of great significance to ensure the safety of these high-rise structures. Many vibration control techniques have been proposed in the past decades, but certain inherent limitations exist in these methods. Recent investigations in the field of solid-state physics have revealed that periodic structures, termed elastic metamaterials, can be used to manipulate the propagation patterns of acoustic/elastic waves. Waves are not able to propagate through the periodic structure when the frequencies of input waves fall within the bandgaps of the structure. This special characteristic has motivated researchers to develop meta-based techniques for structural vibration control. On the other hand, floating floor structure (FFS), in which the floor is isolated from the supporting beam, has been used to control the vibrations of buildings. Inspired by the periodic theory and FFS, in the present study, the conventional underground basement of high-rise building is modified to form a locally resonant meta-basement to block the propagation of seismic waves for mitigation of building vibrations during earthquake excitations. Firstly, the formation of bandgap of the proposed method is demonstrated through analytical study on the infinite number of unit cells and finite element modelling on the finite number of meta-basement. The influences of three key parameters of the meta-basement, i.e., the connecting spring stiffness, the number of meta-basement levels, and the parking ratio on the bandgap characteristics are then examined. Two design strategies of the meta-basement with the capability of reducing the seismic wave energy at frequencies corresponding to the vibration frequencies of the super-structure or reducing the seismic wave energy at its dominant frequency contents are proposed. Numerical simulations are carried out in both the frequency and time domains to evaluate the control effectiveness of the two design strategies on an example building structure. Results show that the proposed meta-basement can reduce the seismic responses of high-rise buildings and designing the meta-basement to mitigate the transmission of seismic wave energy at vibration frequencies of the super-structure is more effective to reduce building vibrations.