1. Research Assistant, Mid-America Earthquake (MAE) Center, Dept. of Civil Engineering, Univ. of Illinois at Urbana-Champaign, 205 N. Mathews Ave., Urbana, IL 61801 (corresponding author). E-mail: nick.burdette@arup.com
2. Bill and Elaine Hall Endowed Professor, Director, MAE Center, Dept. of Civil Engineering, Univ. of Illinois at Urbana-Champaign, 205 N. Mathews Ave., Urbana, IL 61801. E-mail: aelnash@uiuc.edu