1. College of Civil Engineering and Architecture, Zhejiang Sci-Tech Univ., Hangzhou, 310018 Zhejiang, China; Dept. of Geotechnical Engineering, Tongji Univ., 1239 Siping Rd., Shanghai 200092, China.
2. Professor, Dept. of Geotechnical Engineering, Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education, College of Civil Engineering, Tongji Univ., 1239 Siping Rd., Shanghai 200092, China (corresponding author).