1. Professor, Dept. of Bridge Engineering, Tongji Univ. at Shanghai, 1239 Siping Rd., P.R. China.
2. Professor, Dept. of Civil Engineering, Shijiazhuang Railway Institute, Shijiazhuang, P.R. China.
3. Professor, Dept. of Bridge Engineering, Tongji Univ. at Shanghai, 1239 Siping Road, P.R. China.