1. Associate Professor, Dept. of Engineering Science, Univ. of Tehran, 11165-4563 Tehran, Iran.
2. Professor, Dept. of Building Engineering, Tongji Univ., Shanghai 200096, China.
3. Professor, Dept. of Civil Engineering, Univ. of Colorado, Boulder, CO 80309 (corresponding author).
4. Vice Chancellor for Research, Univ. of Colorado, Boulder, CO 80309.