Effects of isolator properties on viscous damper capacity of base isolated adjacent buildings

Base isolation technique requires clearance at the base level around the building. The exceedance of clearance during seismic motion leads to pounding with either the moat wall or adjacent building. This paper analyzes two base isolated adjacent buildings in terms of pounding and searches for optimum linear viscous damper capacity as pounding prevention measure. Changing dynamic characteristics of base isolation device has considerable effect on pounding behavior of adjacent buildings since the period of isolator bearing shifts the fundamental period of the superstructure. For multi-storey buildings, as the number of storey increases, the flexibility of isolated building becomes effective on dynamic behavior and the relative displacement between base and top floors increases. In related with this situation, viscous damper linkage for prevention of pounding may be considered as seismic mitigation solution for base isolated multi-storey buildings. The analyses to find out impact forces and damper capacities are carried out for varied isolator characteristics and storey numbers of buildings. The optimization procedure of linear viscous damper capacities for fixed-base adjacent buildings is modified for base isolated buildings