[Deng Zong-wei;Liu Xi-ling] Cent S Univ, Sch Resources & Safety Engn, Changsha 410083, Peoples R China.^[Leng Wu-ming] Hunan City Univ, Sch Civil Engn & Architecture, Yiyang, Hunan 413000, Peoples R China.^[Leng Wu-ming] Cent S Univ, Sch Civil Engn, Changsha, Hunan 410075, Peoples R China.