Detection of small-scale rockfall incidents using their seismic signature

Abstract

Several algorithms have been effectively used to identify the seismic signature of rockfall incidents, which constitute a significant threat for human lives and infrastructure especially when occurring along transportation networks. These algorithms have been mostly evaluated using data from large scale rockfall events that release a large amount of energy. However, low-energy rockfall events (< 100 Joules) triggered by small-sized individual rocks falling from small heights can be severely destructive. In this study, a three-parameter algorithm has been developed to identify low-energy rockfall events. An experimental setup was implemented to 1) validate the results obtained by this algorithm against visual inspection of seismic signals records, 2) define the optimal algorithm parameterization to minimize false alarms, and 3) investigate whether tri-axial vibration monitoring can be replaced by a uniaxial device in order to reduce the installation cost of a real-time rockfall monitoring system. It was found that the success rate of the proposed algorithm exceeds 80% independently of the parameters used, while event identification at a maximum distance with minimal false alarms was achieved when using mean ± 3σ as the threshold criterion and 6 ms and 4 ms as the trigger and event window parameters respectively. Finally, it was found that for the specific experimental setup, a uniaxial device could be used for rockfall event identification.

The relationship between bulk‐mass momentum and short‐period seismic radiation in catastrophic landslides

“…At the global scale, detection of the long-period surface waves generated by the largest landslides permits the location of events in very remote areas that may otherwise have remained undetected [Ekström and Stark, 2013]. Thanks to continuous recording, seismology can also help to reconstruct the chronology of landslides caused by strong environmental forcing, such as the Talas typhoon in Japan [Yamada et al, 2012] or the Morakot typhoon in Taiwan [Lin et al, 2010], and more generally to study the spatiotemporal activity of gravitational instabilities at a regional or a local scale and in different geological contexts [e.g., Deparis et al, 2008;Helmstetter and Garambois, 2010;Dammeier et al, 2011Dammeier et al, , 2016Hibert et al, 2011Hibert et al, , 2014aClouard et al, 2013;Chen et al, 2013;Burtin et al, 2013;Tripolitsiotis et al, 2015;Zimmer and Sitar, 2015].…”

“…Recently, interest in the information contained in short-period seismic signals (periods shorter than 1 s) generated by gravitational instabilities has grown. Short-period seismic signals are frequently recorded for gravitational instabilities [e.g., Suriñach et al, 2005;Deparis et al, 2008;Dammeier et al, 2011Dammeier et al, , 2016Clouard et al, 2013;Chen et al, 2013;Burtin et al, 2013;Hibert et al, 2014a;Levy et al, 2015;Tripolitsiotis et al, 2015;Zimmer and Sitar, 2015], even for small events with a volume of the order of a cubic meter [Hibert et al, 2011], when a seismic station is close by. Challenges associated with short-period signals are that they attenuate rapidly away from the source, and their complexity has thus far precluded inversion and modeling.…”

Single-block rockfall dynamics inferred from seismic signal analysis

“…Hence, this allows a seismic detection of the events that do not generate long-period seismic waves (e.g. Deparis et al, 2008;Helmstetter and Garambois, 2010;Dammeier et al, 2011Dammeier et al, , 2016Hibert et al, 2011Hibert et al, , 2014bClouard et al, 2013;Chen et al, 2013;Burtin et al, 2013;Tripolitsiotis et al, 2015;Zimmer and Sitar, 2015). The limitation of this approach is that high-frequency seismic waves are more prone to be influenced by propagation effects (attenuation, dispersion, scattering) and, more importantly, that the source of the high-frequency seismic waves associated with gravitational instabilities is not yet well understood.…”

Observation of the rock slope thermal regime, coupled with crackmeter stability monitoring: initial results from three different sites in Czechia (central Europe)

“…Various approaches are used, with a background in geodesy (Gunzburger et al, 2005;Reiterer et al, 2010;Yavasoglu et al, 2020), geotechnics (Greif et al, 2017;Lazar et al, 2018), geophysics (Burjanek et al, 2010;Weber et al, 2017Weber et al, , 2018Coccia et al, 2016;Yan et al, 2019;Weigand et al, 2020;Warren et al, 2013), or remote sensing methods (Sarro et al, 2018;Matano et al, 2015). Most commonly, sensors such as thermometers, accelerometers, inclinometers, visible light or IR cameras, total stations, TLS (terrestrial laser scanner), GbSAR (ground-based synthetic-aperture radar), and seismographs are used to detect potential rockfall events (Burjanek et al, 2010(Burjanek et al, , 2018Tripolitsiotis et al, 2015;Matsuoka, 2019). These methods are more suitable for monitoring large rock slopes.…”