1. Associate Professor, School of Engineering and Technology, China Univ. of Geosciences, Beijing 100083, China (corresponding author).
2. Graduate Student, School of Engineering and Technology, China Univ. of Geosciences, Beijing 100083, China.
3. Associate Professor, Dept. of Geology and Geological Engineering, Colorado School of Mines, Golden, CO 80401.
4. Assistant Professor, Dept. of Earth Sciences, Abbottabad Univ. of Science and Technology, KPK, Pakistan.
5. Professor, College of Urban and Environmental Sciences, Peking Univ., Beijing 100871, China.