EFFECT OF NON-UNIFORMITY IN ISOLATOR STIFFNESS ON TORSIONAL COUPLING OF SUPERSTRUCTURE

Abstract

The need for structural and seismic retrofitting arises due to many reasons like loss of strength of building materials, damage in structures due to earthquakes, inadequate design of structures etc. After the revision of seismic zones in India, existing structures are supposed to be seismically retrofitted for higher expected earthquake forces. Structural retrofitting for earthquakes can be done either by addition of lateral force restraining systems (seismic) or by addition of lateral force reducing systems (aseismic) . Again aseismic retrofitting can be of two types, namely passive and active devices. Base isolation is a passive method for aseismic retrofitting The concept of base isolation suggests an effective measure to reduce the earthquake induced lateral forces on the building. The idea behind the concept of base isolation is quite simple : In this approach, the building or structure is decoupled from the horizontal components of the earthquake ground motion ...