Multi-technique approach to rockfall monitoring in the Montserrat massif (Catalonia, NE Spain)

Abstract

Montserrat Mountain is located near Barcelona in Catalonia, in the northeast of Spain, and its massif is formed by conglomerate interleaved by siltstone/sandstone with steep slopes very prone to rockfalls. The increasing number of visitors in the monastery area, reaching 2.4 million per year, has highlighted the risk derived from rockfalls for this building area and also for the terrestrial accesses, both roads and the rack railway. A risk mitigation plan has been launched, and its first phase during 2014-2016 has been focused largely on testing several monitoring techniques for their later implementation. The results of the pilot tests, performed as a development from previous sparse experiences and data, are presented together with the first insights obtained. These tests combine four monitoring techniques under different conditions of continuity in space and time domains, which are: displacement monitoring with Ground-based Synthetic Aperture Radar and characterization at slope scale, with an extremely non-uniform atmospheric phase screen due to the stepped topography and atmosphere stratification; Terrestrial Laser Scanner surveys quantifying the frequency of small or even previously unnoticed rockfalls, and monitoring rock block centimetre scale displacements; the monitoring of rock joints implemented through a wireless sensor network with an ad hoc design of ZigBee loggers developed by ICGC; and, finally, monitoring singular rock needles with Total Station.Peer ReviewedPostprint (author's final draft

An Overview of Opportunities for Machine Learning Methods in Underground Rock Engineering Design

“…Categorical ANNs [57,86] SVM [87] RF [88,89] Clustering [90] • Predict slope movements based on geometry, piezometers, inclinometer data, etc. • Predict volume of structurally controlled failure based on mapped discontinuities Table 1.…”

3-Dimensional Rockfall Shape Back-Analysis: Methods and Implications

“…rockfall) between sequential TLS scans. The location, volume and dimensions of rockfall on the slope can be calculated and populated into a database, as demonstrated by Rosser et al (2007), Guerin et al (2014), Tonini and Abellan (2014), van Veen et al 2017, Janeras et al (2017) and Williams et al (2018). In several of these studies smaller magnitude rockfalls have been identified, which are often not observed during field inspections performed from the base of the slope.…”

“…,Carrea et al (2015),Janeras et al (2017), van Veen et al (2017 to semi-automatically identify rockfall locations and extract information related to the dimensions of each rockfall event is implemented. A generalized rockfall extraction process is illustrated in the flow chart inFig.…”

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“…Moreover, the whole data collection and post-processing are simple and convenient, making GBSAR an effective supplement to spaceborne SAR and conventional geodetic monitoring instruments. At present, GBSAR is primarily used to monitor landslides [2,[4][5][6], slopes [7], Volcanic activity [8], and glaciers [9], as well as the deformation of large buildings such as dams [9][10][11][12] and towers and bridges [7,13,14]. Antonello et al employed the InGrID-Lisa GBSAR system to monitor the Stromboli Volcano and through the radar measurement it has been possible to assess the deformation field over a large portion of the target area and to differentiate different processes [15].…”