Residual Strength of Cable Stay Strands from Blast Qualification

Abstract

This paper describes the residual strength of damaged strand and wires from protected cable stay bundles subjected to severe blast qualification tests. This effort was motivated by the question: What reserve strength is available, if any, in damaged strands and wires from protected cable stay bundles surviving a blast test? This question arises from performance requirements to evaluate the adequacy of protection mitigation measures for cable stay bundles. To address this question, selected strands and wires from cable stay bundles had their damage characterized and were tested in tension, and then their tension capacity was compared with that of undamaged strands or wires. Testing revealed cold work of the strands from the blast reduces the residual strength by a mean value of 5% and, based on these results, it is recommended to apply a strength reduction factor of 0.95 to all intact or non-severed wires in a cable stay bundle for future blast qualification tests.