1. Graduate Student, Dept. of Geological Science and Engineering, School of Earth Sciences and Engineering, Hohai Univ., Nanjing 210098, China.
2. Professor, Dept. of Geological Science and Engineering, School of Earth Sciences and Engineering, Hohai Univ., Nanjing 210098, China (corresponding author).
3. Assistant Professor, Dept. of Civil Engineering, Univ. of Victoria, Victoria, BC, Canada V8P5C2.
4. Professor, Dept. of Geological Science and Engineering, School of Earth Sciences and Engineering, Hohai Univ., Nanjing 210098, China.