1. Professor, Institute of Geotechnical and Underground Engineering, Shandong Univ., Ji’nan 250061, China.
2. School of Qilu Transportation, Shandong Univ., Ji’nan 250002, China.
3. Assistant Professor, School of Qilu Transportation, Shandong Univ., Ji’nan 250002, China.
4. Assistant Professor, School of Qilu Transportation, Shandong Univ., Ji’nan 250002, China; State Key Laboratory of Intelligent Manufacturing of Advanced Construction Machinery, Shandong Univ., Ji’nan 250061, China (corresponding author).