1. College of Civil and Hydraulic Engineering, Ningxia University, Yinchuan 750021, China
2. Ningxia Center for Research on Earthquake Protection and Disaster Mitigation in Civil Engineering, Yinchuan 750021, China
3. Yinchuan University of Energy, Yinchuan 750100, China
4. School of Transportation, Inner Mongolia University, Inner Mongolia 010021, China