Damage to the freeway bridges in the Whittier Narrows earthquake of October 1, 1987 was one of the most significant aspects of damage to engineered structures designed for seismic lateral loads. Of particular importance was the performance of the I-605/I-5 separator, which was extensively damaged during the earthquake and came perilously close to collapse at a time when freeway traffic was at its heaviest and loss of life would have been extensive. The research project is directed to a study of the performance of freeway bridges in the Whittier Narrows earthquake. The research involves five stages: observed damage assessment, component strength and deformation analysis, dynamic analysis of selected bridge structures, recommendations on assessment and evaluation and prioritization for retrofitting. The intention of the research is to obtain maximum benefit from the lessons emphasized by bridge damage in the earthquake in the form of improved understanding of the vulnerability of existing bridge structures to seismic damage, calibration and assessment of analytical techniques for analysis of seismic response of bridge structures, and in the development and assessment of retrofit techniques to reduce the seismic risk of freeway bridges.
