<title>Continuous acoustic monitoring of suspension bridges and cable stays</title>

Abstract

By adapting a method developed to monitor the failure of post- tensioning cables, it is determined that continuous acoustic monitoring of large suspension cables and cable stays is effective in detecting single wire breaks. This will likely offer a practical method to assist bridge engineers in managing suspension bridges and cable-stay bridges. The practicality of awaiting individual wire failures with computer-based monitoring equipment differs from most acoustic emission work. In continuous monitoring, the signals obtained are not the result of deliberate changes in the stress on an element, but result when the wire breaks spontaneously and suddenly releases the energy stored when cables are placed under load. The acoustic event caused by the failure of a singe wire in the cable is sufficiently large that it can be distinguished from background noise. The identification of the cause of each event and the location of the source of the event should allow targeted and informed repair of broken elements. This paper describes installation methods and challenges, reporting protocols, a description of equipment, software, operations methodologies, and other enabling technologies.