1. a Faculty of Environment & Energy Engineering , Beijing Polytechnic University , Ping Leyuan, Beijing , 100022 , China
2. b Department of Civil Engineering , Dalhousie University , Halifax, Nova Scotia , B3J 1Z1 , Canada
3. c Faculty of Engineering , University of Regina , Regina , Sask. , S4S 0A2 , Canada
4. d Jansson Consulting Services Inc. , Regina , Sask. , S4P 2N1 , Canada