Experimental Study on Seismic Response Mitigation of Complex Structure using Passive Friction Damper

The application of control devices in coupled building system has been recently recognized as an effective alternative for seismic protection. In consideration of passive control approach, most of previous studies focused on application of fluid dampers, and the buildings in the coupled systems were in similar structural configuration. By recognizing the potential merits, such as simple in design, relatively effective in cost and performance reliability, of passive friction damper, this paper reports an experimental investigation to demonstrate the control effectiveness of passive friction damper as a coupling device implemented in a scaled 12-story building structure with 3-story podium structure tested on a shake table at The Hong Kong Polytechnic University. The passive friction damper was designed in such a way that the friction force could be changed independently of frequency and amplitude. Dynamic characteristics of the test models for uncoupled and rigidly connected cases were first identified, which were followed by seismic simulation tests. The effects of coupling configurations including the uncoupled, rigid coupled and passive controlled cases were evaluated. Passive control force level and ground motion on control performance were also examined. Installation of friction damper showed positive results in reduction of absolute acceleration and interstory drift responses of both buildings. Rigidly connecting 12-story and podium structures, in contrast, revealed its inherent tendency in amplifying the response of 12-story building in particular. C.L. Ng, Research Center for Urban Hazards Mitigation (RCUHM), The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong Y.L. Xu, Research Center for Urban Hazards Mitigation (RCUHM), The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong