1. School of Environment and Civil Engineering, Dongguan University of Technology, Dongguan, P. R. China
2. Institute of Geophysics, China Earthquake Administration, Beijing, P. R. China
3. Earthquake Engineering Research & Test Center, Guangzhou University, Guangzhou, P. R. China
4. School of Civil and Hydraulic Engineering, Ningxia University, Yinchuan, P. R. China