[1] Xiangtan Univ, Civil Engn & Mech Coll, Xiangtan 411105, Peoples R China
[2] Hunan Univ, Civil Engn Coll, Changsha 410082, Hunan, Peoples R China
[3] Cent S Univ Forestry & Technol, Coll Civil Engn Architecture & Mech, Changsha 410004, Hunan, Peoples R China