ABSTRACT
This paper will present the scenarios considered for replacement of hanger cables, including considerations from an operational perspective. In summary, the investments are made up front in terms of preparatory activities for future hanger replacements in case this is urgently required, as well as digital health monitoring and inspections enabling data-driven decisions on activities. For the case that a cable is lost (e.g., from a fire), urgent replacement would be desired. Preparatory activities include an engineered manual for handling forces and displacements of hanger replacements, detailing of bespoke equipment and sourcing of replacement hangers.
Global analyses to obtain hanger forces, girder deflections etc. are required in advance of hanger replacements, and thus these are made up front considering scenarios of partial or full hanger replacements with associated special traffic configurations.
A digital health monitoring system is used together with site inspections to give a longer warning for other replacement scenarios and enable data-driven decisions on mitigating actions to prolong the service life. After 25 years of service, the strategies for replacement have been re-assessed, taking into account the experience gained of the hangers in operation at this specific bridge through inspection, digital health monitoring and incidents on the bridge.
