1 Department of Civil Engineering, The University of Hong Kong, Pokfulam, Hong Kong SAR 999077, China.
2 Department of Civil Engineering, Nagoya Institute of Technology (Nitech), Nagoya 466-8555, Japan.
3 Key Laboratory of Resources Conversion and Pollution Control of the State Ethnic Affairs Commission, College of Resources and Environmental Science, South-Central Minzu University, Wuhan 430074, China.