1. PhD Student, Dept. of Civ. and Envir. Engrg., 206 Civil Engineering Build., Tulane Univ., New Orleans, LA 70118. E-mail: acruz@ tulane.edu
2. Assoc. Prof., Dept. of Civ. and Envir. Engrg., 206 Civil Engineering Build., Tulane Univ., New Orleans, LA 70118. E-mail: lauras@ tulane.edu
3. Assoc. Prof., Dept. of Civ. Engrg., Univ. of Missouri-Rolla, 306 Butler-Carlton Hall, 1870 Miner Circle, Rolla, MO 65409. E-mail: rluna@umr.edu