Stability monitoring of a rail slope using acoustic emission

Abstract

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.

Risk-based analysis of monitoring time intervals for landslide prevention

“…Adequate monitoring to identify the kinematic and hydrological aspects together with a climatic parameter can assist in providing an alert before mass movements occur and suggesting a plan to manage risk to people who may be affected (Angeli et al, 2000). To acquire 20 complete information regarding landslide triggering factors and mechanisms, various combinations of monitoring techniques with instruments are usually employed (Dixon et al, 2015). However, pore-water pressure, displacement and deformation were mentioned as the crucial parameters for landslide monitoring and early warning in previous studies (Baroň and Supper, 2013;Uhlemann et al, 2016).…”

Monitoring buried pipe deformation using acoustic emission: quantification of attenuation

“…A band pass filter attenuated signals outside of the 20 to 30 kHz range to eliminate low-frequency background noise (<20 kHz) and to keep the monitored range consistent with that used in slope monitoring field trials using active waveguides (e.g. Smith et al, 2014a;Smith et al, 2014b;Dixon et al, 2015a;Dixon et al, 2015b;Smith, 2015). Amplification of 70 dB was used to improve the signal to noise ratio.…”

“…Generated AE rates are proportional to applied displacement rates, where the coefficient of proportionality Smith et al Monitoring Buried Pipe Deformation Using AE: Quantification of Attenuation 17/08/2016 3 is dependent on the depth to the shear surface and the distance AE propagates along the waveguide to the ground surface where it is measured. Quantifying this magnitude of attenuation for each installation is essential to deriving slope displacement rates from measured AE rates, which can be used to warn users of accelerating slope deformation behaviour to enable evacuation of vulnerable people and timely repair and maintenance of critical infrastructure (Koerner et al, 1981;Nakajima et al, 1991;Smith et al, 2014a;Smith et al, 2014b;Dixon et al, 2015a;Dixon et al, 2015b;Smith, 2015;Smith & Dixon, 2015;Smith et al, 2016).[Insert Figure 1 here] Developments in AE monitoring of pipe networks (e.g. Alleyne & Cawley, 1992;Alleyne & Cawley, 1997) for the detection and location of defects (e.g.…”

Correlation between Acoustic Emission Behaviour and Dynamics Model during Three-Stage Deformation Process of Soil Landslide

“…AE technology has the characteristics of high temporal resolution, strain sensitivity, and lower costs. In addition, AE can be an effective method to quantify the deformation behaviour of a slope [ 23 , 27 , 31 , 32 , 33 ]. The evidence obtained in previous research shows that the AE rate is proportional to sliding velocity [ 23 , 25 , 33 ].…”