Stability monitoring of a rail slope using acoustic emission

The paper details the use of acoustic emission generated by active waveguide subsurface instrumentation to monitor the stability of a rail soil cutting slope failure. Operation of the active waveguide, unitary battery-operated acoustic emission sensor and warning communication system are described. Previous field trials reported by the authors demonstrate that acoustic emission rates generated by active waveguides are proportional to the velocity of slope movement, and can therefore be used to detect changes in rates of movement in response to destabilising and stabilising effects, such as rainfall and remediation, respectively. The paper presents a field trial of the acoustic emission monitoring system at a reactivated rail-cutting slope failure at Players Crescent, Totton, Southampton, UK. The results of the monitoring are compared with both periodic and continuous deformation measurements. The study demonstrated that acoustic emission monitoring can provide continuous information on displacement rates, with high temporal resolution. The ability of the monitoring system to detect slope movements and disseminate warnings by way of text messages is presented. The monitoring approach is shown to provide real-time information that could be used by operators to make decisions on traffic safety.