1. School of Engrg., Dept. of Civ. Engrg., Univ. of Southern California, 3620 S. Vermont Ave., KAP 210, MC 2531, Los Angeles, CA 90089-2531. E-mail: masri@usc.edu
2. School of Engrg. and Appl. Sci., Columbia Univ., 610 S.W. Mudd Bldg., Mail Code 4709, 500 W. 120th St., New York, NY 10027-6699.
3. School of Engrg., California State Univ., Long Beach, CA 90840-5602.
4. Div. of Engrg. and Appl. Sci., Mail Code 104-44, California Inst. of Technol., Pasadena, CA 91125.
5. Anal. and Testing, Los Alamos Nat. Lab., Los Alamos, NM 87545.