1. Department of Geotechnical Engineering, School of Civil Engineering, Southwest Jiaotong University, Chengdu, Sichuan, P. R. China
2. Sichuan Water Development Investigation, Design & Research Co. Ltd., Chengdu, Sichuan, P. R. China
3. China Railway Engineering Corporation (CREC) Sichuan Eco-City Investment Co., Chengdu, Sichuan, P. R. China
4. Sichuan Highway Planning, Survey, Design and Research Institute Ltd., Chengdu, Sichuan, P. R. China