1. School of Materials Science and Engineering , Tianjin Chengjian University , Tianjin 300384 , P. R. China
2. Tianjin Key Laboratory of Soft Soil Characteristics and Engineering Environment , Tianjin 300384 , P. R. China
3. School of Civil Engineering , Tianjin Chengjian University , Tianjin 300384 , P. R. China