Figure : Working Process of Passive Protection System[12].
  1. BASE ISOLATION
Seismic base isolation is a design strategy based on the principle that it is both possible and feasible to uncouple the structure from the ground and thereby protect it from the damaging effects of earthquake motions. To achieve this result, while at the same time satisfying all of the in-service functional requirements, additional flexibility is introduced usually at the base of the structure. Additional damping is also provided so as to control the deflections which occur across the isolation interface.
As for all the load cases, we encounter in the design process, such as gravity and wind, we work to meet a single basic equation: