School of Civil Engineering,Southeast University,Nanjing 211189,China;
The Research and Development Joint Center of Energy Dissipation Technology of Southeast University and Forceset Corporation,Southeast University,Nanjing 211189,China;
School of Civil and Transportation Engineering,Beijing University of Civil Engineering and Architecture,Beijing 100044,China;
Beijing Institute of Architectural Design,Beijing 100045,China;
existing urban RC frame building; retrofitting using seismic isolation; seismic resilience; yield ratio;