KANG Houjun 1,SU Xiaoyang1,GONG Ping2,CAI Xiangyang2,LIU Haibo3,HU Jianhua3,GUO Tieding1
(1.College of Civil Engineering,Hunan University,Changsha410082,China;2.Provincial Ruchen Highway Construction Development Co Ltd,Chenzhou423000,China;3.Hunan Provincial Communications Planning,Survey & Design Institution,Changsha410008,China)