1. Fellow, ASCE
2. Walter P. Murphy Prof. of Civ. Engrg. and Mat. Sci., Northwestern Univ., Evanston, IL 60208. E-mail: z _bazant@northwestern.edu
3. Grad. Res. Asst., Dept. of Civ. Engrg., Northwestern Univ., Evanston, IL.
4. Res. Civ. Engr., U.S. Army Engr. Waterways Experiment Station, Vicksburg, MS 39180.
5. Res. Civ. Engr., U.S. Army Engr. Waterways Experiment Station, Vicksburg, MS.