1. Dept. of Civil and Construction Engineering, National Taiwan University of Science and Technology, No. 43, Sec. 4, Keelung Rd., Taipei, 106, Taiwan (Corresponding author), e-mail: minchih.liao@mail.ntust.edu.tw
2. Sinotech Engineering Consultants, Ltd., No. 171, Sec. 5, 14th Floor, Nanking E. Rd., Taipei City, 105, Taiwan
3. Dept. of Civil and Construction Engineering, National Taiwan University of Science and Technology, No. 43, Sec. 4, Keelung Rd., Taipei, 106, Taiwan