1. School of Civil Engineering, Qingdao University of Technology, Qingdao 266033, China
2. Tunnel Engineering Co., Ltd., China Communications Construction, Beijing 100024, China
3. The Fifth Engineering Co., Ltd., China Railway 25th Bureau Group, Qingdao 266101, China
4. Engineering Bureau Co., Ltd., China State Construction, Changsha 410007, China
5. Qingdao Metro Line 1 Co., Ltd., Qingdao 266045, China