Coupling of buildings by viscous dampers and nonlinear response estimation

ABSTRACT This paper deals with analysis of two adjacent buildings, one of which does not fulfil code requirements. Earthquake loads cause an opening gap at soil-foundation contact of concrete walls, founded on strips. This nonlinearity was analysed by nonlinear static analysis and resulting effective stiffness was used to update structural eigenfrequencies and modes shapes. Comparison to linear response spectra analysis showed large differences, especially in stress distribution. Retrofitting by installing viscous dampers is proposed. Dampers are positioned at the roof and provide coupling of adjacent buildings. Dampers ensure force transfer between the buildings, increase modal damping, and avoid pounding of the adjacent buildings. They provide a convenient method of retrofitting, since hospital operation is not disturbed by the installation.