1. Professor, Institute of Geotechnical Engineering, Southeast Univ., Nanjing 210096, China.
2. Professor, Institute of Geotechnical Engineering, Southeast Univ. (SEU), Nanjing 210096, China (corresponding author).
3. Doctoral Student, Institute of Geotechnical Engineering, Southeast Univ., Nanjing 210096, China.
4. Professor, Dept. of Civil Engineering, Univ. of Texas at Arlington, Arlington, TX 76019; presently, Visiting Professor, Institute of Geotechnical Engineering, Southeast Univ., Nanjing, China.