1. Department of Civil and Safety Engineering, Dalian Jiaotong University, Dalian, Liaoning Province 116028, P. R. China
2. Department of Civil and Environmental Engineering, University of Massachusetts Amherst, 38 Marston Hall, 130 Natural Resources Road, Amherst, Massachusetts 01003-0724, United States
3. Geochemistry and Materials Science Research, Sandia National Laboratories, Albuquerque, New Mexico 87185-0754, United States