1,721,126 research outputs found
ONE OF THE HAZARDOUS NEIGHBOURS OF THE VAJONT LANDSLIDE: THE HISTORICAL M. SALTA ROCK-BLOCK SLIDE-ROCK FALL
Full text linkIn the Vajont Valley (north-eastern Alps), the everlasting interactions between endogenic (tectonic, seismic, isostatic) and exogenic (glacial, slope, anthropogenic) processes have resulted in a hazardous environment. The most striking geomorpho-logical feature of the valley is the evidence of several landslide processes of different type, age, and size. The October 1963 catastrophic landslide is undoubtedly the most notorious one. However, the Pineda and Salta landslide events have left enduring signatures in the landscape of the valley. In particular, the wide landslide deposit upslope Casso, on the southern slope of M. Salta, derives from multiple overlapping events. Rock planar slides, topples, and rock falls occur since centuries, displaying a complex-composite style of activity. Nowadays, in this area, slope processes are still active and are threatening the village of Casso and the visitors of the 1963 disaster site
Structural health monitoring of a road tunnel intersecting a large and active landslide
Full text linkDealing with engineering structures that are not easily replaceable requires frequent assessment of the damage state of the construction in order to estimate its durability and reliability. The procedures that allow damage to be detected and identified are broadly defined as Structural Health Monitoring (SHM). In this work, a SHM network has been deployed in a road tunnel that intersects a massive landslide, whose movements are causing the formation of cracks along the tunnel lining. The monitoring system measures in real time the displacements across major cracks and the rotation of the tunnel segments; data are gathered and made easily accessible through a web-based platform. The mechanisms by which the tunnel deforms under the landslide-induced stress have been defined through the analysis of three years of monitoring data. The factors triggering an increase in deformation rates and causing damage to the structure have also been investigated. This evidence will support the design of mitigation works to extend the life-span of the tunnel
Web-Based Platforms for Landslide Risk Mitigation: The State of the Art
Full text linkWeb-based platforms (WBPs) are online spaces where the user can interrogate and analyze data series gathered in quasi-real time from monitoring network/s. These online tools are increasingly used by government agencies, local authorities, contractors, and researchers for visualization, management, control, and analysis of monitoring data. In the risk mitigation framework, WBPs must incorporate specific tools and functions to be integral to non-structural mitigation activities. This is particularly important for the mitigation of landslide-related hazards, that sometimes are challenging to address with structural solutions. The state-of-the-art paper considers the evolution of WBPs for risk mitigation from a pioneering research topic of a decade ago to the current applications that are sometimes comprised within commercial packages. First, we describe what nowadays represents the WBP requirements regarding usability and data visualization for proper data communication. Next, tools for data management and solution regarding interoperability and data analysis are discussed. Lastly, considerations on data filtering in the context of alert and alarm triggering are presented. To be a reasonable alternative to structural mitigation works, non-structural solutions such as monitoring for alarm triggering or early warning must be dependable and stable. We have synthesized the fundamental requirements of monitoring networks devoted to risk mitigation with the expression "5 Rs": robustness, redundancy, reliability, resilience, and responsiveness
Integration of terrestrial laser scanning and thermal imaging aimed to characterize the joints of a sedimentary rock cliff.
No full textData fusion for dissemination: Web applications for the visualization of monitoring data
No full textA monitoring system with an integrated web platform that has been installed to control the deformations of a road tunnel that intersects a block slide is presented. The system has been implemented in order to be redundant, scalable and providing the possibility to integrate different types of sensors. In fact, due to the importance of the monitored infrastructure the system needed to be extremely robust and reliable. The web platform has been designed focusing on the usability that is the ease of use and learnability. In fact, when monitoring a landslide or a structure, displacements are one of the main measured quantities. However, collected data are usually difficult to communicate with the classic displacements vs time graphs to local authorities and to the public. An automatically generated heat maps is available on the platform and the fact that the most active areas are identified with a reddish color while lesser movements are indicated in yellow uses a well-known communication code that helps understanding the dynamic of the process in a more intuitive way. On the other hand the possibility to have a single image available on the web to every person involved in the project helps the dissemination of results and confrontation creating an accessible common ground in the emergency phase
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Appraise the structural mitigation of landslide risk via numerical modelling: a case study from the northern Apennines (Italy).
No full textCumulative monitoring of strain in concrete structures with polymer optical fibers
No full textAn alternative approach to spatial sampling of strain and displacement, other than point-wise and distributed, is here proposed to the aim of crack monitoring in civil structures. The addressed method exploits a low cost optical technique for the measurement of the cumulative deformation of a polymer optical fibre (POF), used as a sensing element and is suitable for both dynamic and static measurements. Main features of this approach are the limited cost, the large dynamic deformation range enabled by POF, the large area covered by a single sensor, ruggedness and easiness of handling. The feasibility of the approach is demonstrated in a real test site scenario, in which the sensing system is used for long-term monitoring of cracks originated inside a road tunnel impacted by a landslide. Some general considerations will be also drawn about the possible application of that sensing system to the monitoring of physical measurands of geo-technical interest, other than strain
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