1. Earthquake Engineering Research and Test Center (EERTC), Guangzhou University, Guangzhou 510006, P. R. China
2. Key Laboratory of Earthquake Resistance Earthquake, Mitigation and Structural Safety of Ministry of Education, Guangzhou University, Guangzhou 510006, P. R. China
3. Department of Civil and Mineral Engineering, University of Toronto, Toronto M5S 2E8, Canada