Damped interconnection-based mitigation of seismic pounding between a R/C tower and a masonry church

Abstract

Damped interconnection represents an advanced strategy to mitigate the effects of seismic pounding between adjacent structures built at poor mutual distance. The effects of pounding can be particularly severe in slender R/C structures, including civic or bell towers. An emblematic case study falling in this class of structures, i.e. a monumental R/C bell tower constructed in the early 1960s in Florence, is analyzed in this paper. In order to assess the effects of pounding, a non-linear dynamic finite element enquiry was carried out by simulating collisions between the tower and the adjacent masonry church with a multi-spring-damper viscoelastic contact model, originally implemented in this study. The survey results show that pounding affects the seismic response of the two buildings as early as an input seismic action scaled at the amplitude of the normative basic design earthquake level. A damped interconnection-based retrofit hypothesis to prevent pounding is then proposed, which consists in linking the two structures by means of a pair of fluidviscous dissipaters. Thanks to the added damping produced by these devices, the impacts are totally annulled, bringing the structural members of the tower to safe levels.