1. College of Civil Engineering, Guizhou University, Huaxi District, Guiyang, Guizhou Province 550025, P. R. China; and Guizhou Provincial Key Laboratory of Rock and Soil Mechanics and Engineering Safety, Huaxi District, Guiyang, Guizhou Province 550025, P. R. China
2. College of Civil Engineering, Guizhou University, Huaxi District, Guiyang, Guizhou Province 550025, P. R. China; and Guizhou Provincial Key Laboratory of Rock and Soil Mechanics and Engineering Safety, Huaxi District, Guiyang, Guizhou Province 550025, P. R. China (Corresponding author), e-mail: demonjjun@126.com, http://orcid.org/0000-0002-0293-4355
3. School of Civil Engineering, Guangzhou University, No. 230, Huanxi Rd., Guangzhou, Guangdong 510006, P. R. China