The dramatic sights of large amplitude vibration, of stay cables, gushing water from stay cable anchorage sockets, anchor pipes cracked due to impact of cables, and splitting of polyethylene pipes on the cables with exposed steel wires open to corrosive environment are vivid reminders that all is not well with these singularly beautiful cable stay bridges in the US. Incidences of large-amplitude vibrations of stay cables on the order of 1 to 1.8 meters under certain combinations of light rain and moderate wind have been reported worldwide. In addition to the cable vibrations, other significant problems associated with stay cable systems have been observed on several other bridges in the US and abroad. The gravity and severity of the problems, and its potential for causing significant future damage propelled several investigators to vigorously pursue a course to systematically and comprehensively evaluate, assess, and mitigate the problems of our nations' signature cable stayed bridges. Over the past six years, the authors have been involved in research and development of new techniques for condition assessment of cable stayed bridges and have implemented these methods successfully for evaluation of several landmark bridges in the US. This paper attempts to highlight the lessons learnt from these investigations and provides a comprehensive discussion on assessment of shortcomings of current practices.
