1. Associate Professor, Dept. of Civil Engineering, Qingdao Univ. of Technology, Qingdao 266033, China.
2. Master’s Candidate, Dept. of Civil Engineering, Qingdao Univ. of Technology, Qingdao 266033, China.
3. Professor, School of Civil Engineering and Architecture, Guangxi Univ., Nanning 530004, China.
4. Professor, Dept. of Civil Engineering, Qingdao Univ. of Technology, Qingdao 266033, China (corresponding author).