1. Professor, ACEI, Dept. of Earth Sciences, Nanjing Univ., Nanjing 210093, China (corresponding author).
2. Graduate Student, ACEI, Dept. of Earth Sciences, Nanjing Univ., Nanjing 210093, China.
3. Associate Professor, Dept. of Civil Engineering, Nanjing Univ. of Aeronautics and Astronautics, Nanjing 210016, China.