1. Key Laboratory of Civil Engineering Safety and Durability of China Education Ministry; Department of Civil Engineering, Tsinghua University; Beijing; 100084; China
2. Hyogo Earthquake Engineering Research Center; National Research Institute for Earth Science and Disaster Prevention; Shinjimicho; Miki; Hyogo; 673-0515; Japan
3. Structural Engineering Research Center; Tokyo Institute of Technology; Yokohama; 226-8502; Japan
4. Disaster Prevention Research Institute; Kyoto University; Gokasho; Uji; Kyoto; 611-0011; Japan