1. Professor, Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering, Hohai Univ., No. 1, Nanjing 210098, China (corresponding author).
2. Ph.D. Student, Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering, Hohai Univ., No. 1, Nanjing 210098, China.
3. Professor, Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering, Hohai Univ., No. 1, Nanjing 210098, China.
4. Professor, Dept. of Civil Engineering, Shandong Univ. of Science and Technology, No. 579, Huangdao, Qingdao, 266510, China.