Corroded Suspension Bridge Cables: Some Lessons Learned

This paper describes some lessons learned after using NCHRP Report 534 for strength assessment of corroded parallel wire cables in large suspension bridges. It describes a number of aspects where I believe improvements can be made. Theoretical defects in the methods used to model wire strengths are discussed, and the high importance placed on numbers of so-called cracked wires is questioned. New data suggests that the influence of wrapping wire in redeveloping the strength of broken wires has been underestimated. It will also present some discussion of structural reliability aspects and safety factors which are relevant to the interpretation of theoretical cable strength calculations.