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The complexity and variability of the structural distribution and combination characteristics of jointed rock masses make the response mechanism of tunnel rock collapse different, and there is a lack of systematic research on the existing perimeter rock instability mode and bolt support scheme. Based on numerical simulations of the block system structure of a nodular rock mass, the existing theory of bolt support is compared and analyzed to explore the scope of their respective applications. Combined with the spatial and temporal transport law of block instability, a new batch instability model of jointed rock tunnels is proposed, which reveals the progressive collapse catastrophe evolution mechanism of a collapsed interlocking block system after the instability of the key blocks and elucidates the coupling mechanism between the bolts and the block system structure as well as their anchoring effectiveness. Finally, for the actual tunnel project, the instability batches of the surrounding rock are identified, and the corresponding optimized design of the bolt support is presented, which has achieved good support effects. The research results can provide important theoretical guidance and practical engineering value for risk avoidance, disaster identification and targeted prevention and control of dangerous rock fall and chain collapse instability disasters in jointed rock body tunnels. [ABSTRACT FROM AUTHOR]

Rockfall represents one of the most destructive geomorphic processes for infrastructure and settlements located at the foot of mountain slopes. Furthermore, it poses a hazard for visitors and hikers. Despite the high anthropic activity in these environments, research on the reconstruction of rockfall in the high mountains of Mexico is still scarce. We used dendrochronological, dendrogeomorphological and lichenometric approaches to study the age and rockfall dynamics in a talus slope in central Mexico. Tree- ring chronologies were constructed from 140 samples of 50 Pinus hartwegii trees, 10 Juniperus monticola shrubs and 16 Ribes ciliatum shrubs to determine the age, frequency and rockfall stability at the upper limit of the forest (~4000 m a.s.l.). 52% of the tree samples showed impact scars, 39% callus tissue, 7% growth suppression and 2% corresponded to trees killed by rockfall. The frequency of rockfalls has increased since the second half of the 20th century, with the 1990s being the period of greatest activity. The years with the greatest disturbance were 1991, 1994 and 1998, possibly due to the intense rainfall that accumulated during the summer, as well as the earthquakes recorded in central and southern Mexico with magnitudes ⩾6. For the lichenometric analysis, 231 thalli of Rhizocarpon geographicum were measured in an active rockfall area. The results suggested three areas of rockfall activity. In the first area the ages were from 61 (±5 year) to 322 years (±41 year). In the second area, the ages were from 12 (±3 year) to 50 years (±12 year). The third area corresponds to an active zone with lichen-free blocks, located near the escarpment. The combination of dendrochronological and lichenometric methods allows a better determination of the minimum ages of rockfall, frequency, spatial distribution, and their possible factor triggers. [ABSTRACT FROM AUTHOR]

The aim of this study is to investigate the rockfall potential of the steep rock slope above the Sumela Monastery (Trabzon, Türkiye) by using Ground Penetrating Radar (GPR) and surface fracture analysis on discontinuity. In this context, studies were carried out on 10 risky blocks determined after the investigations made by a team of industrial mountaineering and observations on the orthophotos. The discontinuity analysis data on the rock masses containing of mainly andesites and basalts were combined with discontinuities observed in the ground penetrating radar sections (radargrams) and the risk status of the blocks was revealed by using the location and characteristics of the dominant discontinuities. By using GPR data, discontinuities with 4 main sets were detected in 3 blocks at a depth of 2.0–2.5 m from the surface and the loose rocks were removed from the slopes using a combination of manual and mechanical techniques, including the use of lifting jacks and jackhammers, as well as explosives. In another block where GPR measurements were taken, a main fracture was detected from the surface to a depth of 2 m, but the continuity of the fracture to a deeper depth was not observed. Thus, this block was reinforced together by wrapping them with steel nets. Ground penetrating radar measurements could not be taken from the other six blocks because they did not have smooth surfaces. The stability of these blocks, which are smaller than the others, was assessed using observational data collected in situ by industrial climbers. In addition, the monastery was opened to visitors after the other small blocks on the slope that were at risk of falling were dropped. It has been demonstrated that fracture-crack systems of rocks on steep and weathered rock slopes, which are difficult to apply in rock engineering studies, can be successfully visualized using GPR measurement. [ABSTRACT FROM AUTHOR]

Rockfall phenomena are considered highly dangerous due to their rapid evolution and difficult prediction without applying preventive monitoring and mitigation actions. This research investigates a hazardous site in the Municipality of Vecchiano (Province of Pisa, Italy), characterized by vertical rock walls prone to instability due to heavy fracturing and karst phenomena. The presence of anthropical structures and a public road at the bottom of the slopes increases the vulnerability of the site and the site's risk. To create a comprehensive geological model of the area, Unmanned Aircraft System (UAS) photogrammetric surveys were conducted to create a 3D model useful in photointerpretation. In accessible and safe areas for personnel, engineering–geological surveys were carried out to characterize the rock mass and to define the portion of rock walls to be monitored. Results from nine multitemporal Robotic Total Station (RTS) measurement campaigns show that no monitoring prisms recorded significant displacement trends, both on the horizontal and vertical plane and in differential slope distance. Additionally, satellite Persistent Scatterer Interferometry (PSI) analysis indicates that the slopes were stable over the two years of study. The integration of these analysis techniques has proven to be an efficient solution for assessing slope stability in this specific rockfall-prone area. [ABSTRACT FROM AUTHOR]

Effective use of the wealth of information provided by Distributed Acoustic Sensing (DAS) for mass movement monitoring remains a challenge. We propose a semi‐supervised neural network tailored to screen DAS data related to a series of rock collapses leading to a major failure of approximately 1.2 million m3 ${\mathrm{m}}^{3}$ on 15 June 2023 in Brienz, Eastern Switzerland. Besides DAS, the dataset from 16 May to 30 June 2023 includes Doppler radar data for partially ground‐truth labeling. The proposed algorithm is capable of distinguishing between rock‐slope failures and background noise, including road and train traffic, with a detection precision of over 95% $95\%$. It identifies hundreds of precursory failures and shows sustained detection hours before and during the major collapse. Event size and signal‐to‐noise ratio (SNR) are the key performance dependencies. As a critical part of our algorithm operates unsupervised, we suggest that it is suitable for general monitoring of natural hazards. Plain Language Summary: Steep mountains and hills produce dangerous rockfalls and similar phenomena such as landslides and debris flows. A major collapse is typically preceded by a series of rockfalls over days or months. It is therefore crucial to reliably detect these events and recognize the warning signs of an impending major collapse. When rocks bounce on the ground they release seismic waves, which generate vibrations that propagate long distances. Such vibrations stretch and compress fiber optic cables within the ground enough so they can be measured with a novel technique called Distributed Acoustic Sensing (DAS). Here we show how to identify such DAS signals using machine learning algorithms to detect precursory rockfall activity and a major collapse on a slope in Switzerland. We compare our detections with radar measurements, which are highly reliable but also come at a greater cost for installation. Since we can apply DAS to unused fiber within the ground, our approach may pave the way for the next generation of natural hazard warning. Key Points: A semi‐supervised neural network is developed for rock‐slope failure monitoring with Distributed Acoustic Sensing at Brienz, SwitzerlandOur model achieves over 95% precision for rock slope failures detected by a Doppler radar system over 45 daysThe sustained detection of slope failures before the major collapse highlights the potential of our approach for early warning [ABSTRACT FROM AUTHOR]

The document discusses the theory and technology for preventing mine water disasters, emphasizing the importance of mine water disaster prevention for safe mining operations. Various studies explore advanced detection methods, disaster prevention technologies, and risk assessment approaches to enhance mine safety and promote sustainable development in the mining industry. The research findings cover topics such as detecting concealed water-conducting faults, monitoring drainage tunnel intrusions, studying landslide initiation mechanisms, analyzing hydrogeochemical characteristics of groundwater, and developing prediction models for water-conducting fracture zones. These studies provide valuable insights for addressing water hazards in coal mines and offer practical engineering applications and methodological guidance. [Extracted from the article]

As a main functional component of rock sheds in rockfall protection projects, traditional sand cushions have shortcomings such as heavy weight and weak buffering capacity. EPS bead-sand cushion can effectively solve these problems, but its buffering mechanism has not been fully revealed. In this study, a series of impact tests were carried out to investigate the performance of EPS bead-sand cushions with different EPS bead contents, and the evolutions of rockfall impact force, penetration depth, earth pressure, and slab vibration under single impact and multiple impacts were comparatively analyzed. The results show that with the addition of EPS beads, the maximum impact force, the peak earth pressure, and the vibration acceleration are significantly reduced. However, the cushion with high EPS bead content is at risk of being penetrated under high energy or multiple impacts, leading to excessive concentration of impact stresses. Furthermore, the EPS beads can alleviate the hardening of the sand cushion under impact through their deformation coordination, but excessive penetration should be prevented in the design of EPS bead-sand cushions. On this basis, combined with traditional sand cushion design theory, an estimation method for the maximum impact force applicable to EPS bead-sand cushion was proposed. The research results can provide a reference for the design and optimization of cushions in actual projects. [ABSTRACT FROM AUTHOR]

This paper introduces the use of point cloud processing for extracting 3D rock structure and the 3DEC-related reconstruction of slope failure, based on a case study of the 2019 Pinglu rockfall. The basic processing procedure involves: (1) computing the point normal for HSV-rendering of point cloud; (2) automatically clustering the discontinuity sets; (3) extracting the set-based point clouds; (4) estimating of set-based mean orientation, spacing, and persistence; (5) identifying the block-forming arrays of discontinuity sets for the assessment of stability. The effectiveness of our rock structure processing has been proved by 3D distinct element back analysis. The results show that SfM modelling and rock structure computing provides enormous cost, time and safety incentives in standard engineering practice. [ABSTRACT FROM AUTHOR]

In this paper, the finite element analysis method is used to extensively study the response of rockfall impact on pipelines with different erosion resistant coating. Based on the numerical results, the safety of the pipeline is comprehensively evaluated. Firstly, through the establishment of detailed pipeline and rockfall models, the impact of different rockfall materials and speeds on the pipeline is simulated. The results of the finite element analysis indicate that rockfall impact can cause significant stress concentration and deformation in the pipelines and damage to the coating. With the increment of impact speed, the damage to the pipeline also increases significantly, and different rockfall materials exhibit varying damage conditions, and it is found that fibreglass reinforced epoxy is better than the polyethylene coating. By comparing the analysis results under different conditions, the safety threshold of the pipeline under various rockfall impact scenarios is obtained. This provides an important theoretical basis and reference for the protection design and safety maintenance of the pipeline. The research in this paper not only aids in deepening the understanding of the mechanism of rockfall impact on pipelines but also serves as a valuable reference for improving the safety and reliability of pipeline engineering. [ABSTRACT FROM AUTHOR]

Small communities in the Arequipa region of Peru are susceptible to rockfall hazards, which impact their lives and livelihoods. To mitigate rockfall hazards, it is first necessary to understand their locations and characteristics, which can be compiled into an inventory used in the creation of rockfall hazard rating maps. However, the only rockfall inventory available for Arequipa contains limited data of large, discrete events, which is insufficient for characterizing rockfall hazards at the community scale. A more comprehensive inventory would result in a more accurate rockfall hazard rating map—a significant resource for hazard mitigation and development planning. This study addresses this need through a remote method for rockfall hazard characterization at a community scale. Three communities located in geographically diverse areas of Arequipa were chosen for hazard inventory and characterization, with a fourth being used for validation of the method. Rockfall inventories of source zones and rockfall locations were developed using high-resolution aerial imagery, followed by field confirmation, and then predictions of runout distances using empirical models. These models closely matched the actual runout distance distribution, with all three sites having an R2 value of 0.98 or above. A semi-automated method using a GIS-based model was developed that characterizes the generation and transport of rockfall. The generation component criteria consisted of source zone height, slope angle, and rockmass structural condition. Transport was characterized by rockfall runout distance, estimated rockfall trajectory paths, and hazard ratings of corresponding source zones. The representative runout distance inventory model of the validation site matched that of a nearby site with an R2 of 0.98, despite inventorying less than a third of the number of rockfalls. This methodology improves upon current approaches and could be tested in other regions with similar climatic and geomorphic settings. These maps and methodology could be used by local and regional government agencies to warn residents of rockfall hazards, inform zoning regulations, and prioritize mitigation efforts. [ABSTRACT FROM AUTHOR]

Ground reinforced embankment (GRE) is an economical and efficient protection measure against rockfalls. In various design guidelines of ground reinforced embankments, the impact force of the rockfall is the principal factor, which is significantly affected by rockfall shape. This article conducts real scale tests and numerical tests to observe the external deformation behavior and the internal dynamic response of GREs subjected to lateral impact. Five shapes of the rockfalls corresponding to three contact types are set up in the tests. The experimental results show that the impact surface shapes of the rockfalls govern the penetration deformation patterns of the embankments, and the deformation extent of the disturbed soils. For different contact types between rockfalls and construction materials, the failure mode of the geosynthetics and the displacement distribution of the disturbed soils are distinguishing. The disturbed soils can be divided into two parts, the part surrounds the rockfall mainly expands laterally, and the rest is extruded and slips backward. Basically, the sharpness of the rockfall results in the deeper penetration and the smaller impact force. The influence of the rockfall shape needs to be carefully considered in the design of ground reinforced embankments. • The sharper rockfall results in deeper penetration and smaller impact force. • The failure of the geosynthetics and the displacement of the disturbed soils are affected by the rockfall shape. • The impact force of the rockfall is determined by the deformation extent of the disturbed soils. • The disturbed soil is divided into two parts, one part expands laterally, the other is extruded and slips backward. [ABSTRACT FROM AUTHOR]

Pile–slab retaining walls, as innovative rockfall protection structures, have been extensively utilized in the western mountainous regions of China. With their characteristics of a small footprint, high interception height, and ease of construction, these structures demonstrate promising potential for application in mountainous regions worldwide, such as the Himalayas, Andes, and Alps. However, their dynamic response upon impact and impact resistance energy remain ambiguous due to the intricate composite nature of the structures. To elucidate this, an exhaustive dynamic analysis of a four-span pile–slab retaining wall with a cantilever section of 6 m under various impact scenarios was conducted utilizing the finite-element numerical simulation method. The rationality of the selected material constitutive models and the numerical algorithm was validated by reproducing two physical model tests. The simulation results reveal the following. (1) The lateral displacement of the pile at the ground surface and the concrete damage under the pile at the impact center are greater than those under the slab at the impact center, implying that the impact location has a significant influence on the stability of the structure. (2) There is a positive correlation between the response indexes (impact force, interaction force, lateral deformation of pile and slab, concrete damage) and the impact velocities. (3) The rockfall peak impact force, the ratio of the peak impact force to the peak interaction force, and lateral displacement of the pile at the ground surface had strong linear relationships with rockfall energy. (4) Relative to the bending moment, shear force, and damage degree, the lateral displacement of the pile at the ground surface is the first to reach its limit value. Taking the lateral displacement of the pile at the ground surface as the controlling factor, the estimated maximum impact energy that the pile–slab retaining wall can withstand is 905 kJ in this study when the structure top is taken as the impact point. In cases where the impact energy of falling rocks exceeds 905 kJ , it is recommended to optimize the mechanical properties of the cushion layer, improve the elastic modulus of concrete, increase the reinforcement ratio of longitudinal tension bars, enlarge the section size of piles at ground level, or add anchoring measures to enhance the bending resistance of the retaining structure. [ABSTRACT FROM AUTHOR]

In practical engineering, a shed-tunnel structure often encounters repeated impacts from rockfall during its whole service life; therefore, this research focuses on exploring the dynamic response characteristics of shed-tunnel structures under repeated impacts from rockfall with a numerical method. First of all, based on a model test of a shed tunnel under rockfall impacts as a reference, an FEM (finite element method)-SPH (Smoothed Particle Hydrodynamics) coupled numerical calculation model is established based on the ANSYS/LS-DYNA finite element code. Numerical simulation of the dynamic response of the shed-tunnel structure under rockfall impacts is realized, and the rationality of the model is verified. Then, with this model and the full restart technology of the LS-DYNA code, the effects of four factors, e.g., rockfall mass, rockfall impact velocity, rockfall impact angle and rockfall shape, on the impact force and impact depth of the buffer layer, the maximum plastic strain and axial force of the rebar, the shed roof's vertical displacement and plastic strain of the shed tunnel are studied. The results show that the impact force, impact depth, roof displacement and plastic strain of the shed tunnel are positively correlated with the rockfall mass, velocity and angle under multiple rockfall impacts. The impact force, roof displacement and plastic strain of the shed-tunnel structure generated by the impact of rockfall consisting of cuboids are all greater than those under spherical rockfall, and the impact depth generated by the impact of spherical rockfall is greater than that of rockfall consisting of cuboids. For rockfall consisting of cuboids, the impact depth, roof displacement and plastic strain are negatively correlated with the contact area. Under repeated rockfall impacts, the peak impact force usually increases first and then tends to be stable. [ABSTRACT FROM AUTHOR]

Copyright of Transportation Science & Technolgy is the property of Transportation Science & Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to study the influence law of rockfall on the train running safety of railway bridges, a simply supported box girder bridge on a railway in western mountainous area was taken as the research object. A rockfall impact simulation model and a vehicle-track-bridge coupling dynamic analysis model, which fully considered material nonlinearity and contact nonlinearity, were established. The characteristics of rockfall impact force on bridge piers were clarified, and the train running safety on the bridge under rockfall impact was analyzed. The influence of rockfall impact speed, angle, height, and rockfall diameter on running safety was also revealed. The results showed that: (1) The peak impact force value of rockfall increased with the speed and diameter of the rockfall, while the impact height and angle had little effect on the peak impact force. (2) The increase in rockfall diameter enlarged the damage range of the pier structure, characterized by the appearance of multiple impact force peaks and an extended impact force time history. (3) The faster the rockfall impact speed and the greater the impact energy, the more significant the threat to train running safety on the bridge. The closer the rockfall impact height was to the top of the pier and the larger the diameter of the falling rock, the greater the lateral dynamic response of the train, posing a higher threat to train safety on the bridge. (4) The variation patterns of the time-history curves of each safety evaluation index of the train under different working conditions were similar across different impact angles of rockfall, with minimal changes in their impact on train safety. (5)The wheel load reduction rate was highly sensitive to rockfall diameter and impact height. The wheel load reduction rate exceeded the standard limit when the rockfall diameter reached 2. 5 meters. The research results will provide a reference for the whole life cycle design and safe operation and maintenance of railway bridges in western mountainous area. [ABSTRACT FROM AUTHOR]

The distribution of freezing and thawing within rock masses is time varying (day to day or season to season) and controls the effectiveness of the frost cracking processes from the surface until various depths. These processes are major contributors to the development of rock instabilities. By altering the thermal regime of rockwalls, global warming could have a major impact on rockfall dynamic by the end of the 21st century. This study seeks to improve our understanding of the influence of this warming on (i) the distribution of freezing and thawing within rock masses, (ii) the effectiveness of frost cracking and (iii) the frequency and magnitude of rockfalls. Thermistor sensors inserted in a 5.5‐m horizontal borehole and a weather station were installed on a vertical rockwall located in the northern Gaspé Peninsula (Canada). This instrumentation was used to calculate the surface energy balance of the rockwall and to measure and model its thermal regime at depth over a period of 28 months. Combining locally recorded historical air temperature data with simulated future data (scenarios RCP4.5 and RCP8.5) made it possible to extend the rockwall thermal regime model over the period 1950–2100. The effectiveness of frost cracking over this 150‐year period has been quantified using a thermomechanical model. Depending on the scenario, warming of 3.3°C to 6.2°C is expected on the northern Gaspé Peninsula by the end of the 21st century. This rapid warming is likely to decrease the maximum depth reaches by the seasonal frost by 1–2 m and shorten its duration by 1–3 months. The frequency of freeze–thaw cycles could increase twelvefold in January. Frost cracking effectiveness should intensify around 70 cm in depth and disappear beyond that (RCP4.5) or diminish starting at 10 cm in depth (RCP8.5). In areas subject to seasonal freeze–thaw cycles, decimetric rockfall frequency could grow considerably in winter but be significantly reduced in fall and spring. Furthermore, frost cracking would cease contributing to the development of larger magnitude instabilities. [ABSTRACT FROM AUTHOR]

Rockfalls, a common geohazard in mountainous areas, have destructive impact capacity and may cause failure of dangerous rock masses in their runout range. For slope risk assessment, a thorough understanding of the impact failure processes and dynamic characteristics associated with rockfall movements is necessary. The aim of this study is to investigate the impact of rockfall failure behaviours and disaster processes on the dangerous rock mass along the way through three‐dimensional discontinuous deformation analysis (3D DDA). To validate the reliability and applicability of 3D DDA, numerous laboratory experiments are performed on the impact of downward moving blocks on the unstable block and block system (i.e. single block–single block, single block–block system and block column–block system models) by comparing the displacements, kinetic energies and movement states of blocks. Using the G318 national road in Tibet as an example, 3D DDA simulates the impact and disaster processes associated with upper rockfalls sourced from a complete giant block and multiple discrete blocks on lower dangerous rock mass. Further, rockfall failure modes, movement characteristics, block interactions and impact phenomena are investigated. Results show that 3D DDA can effectively simulate block movement and impact interaction. The upper rockfalls impact the initially stable lower dangerous rock mass, which is the triggering factor for failure of the lower dangerous rock mass. The blocks from the upper rockfalls interact and merge to move downward, increasing the total volume and impact capacity of the rockfalls. It has been discovered that the rockfall disaster caused by the impact of an upper rockfall comprising discrete blocks on a lower dangerous rock mass is more severe than that resulting from the impact of a complete block. Overall, the results of this research can be used to help predict and prevent rockfall disasters. [ABSTRACT FROM AUTHOR]

We explore the viability of modeling dynamic problems with a new formulation of an impulse‐based Level‐Set DEM (LS‐DEM). The new formulation is stable, fast, and energy conservative. However, it can be numerically stiff when the assembly has substantial mass differences between particles. We also demonstrate the feasibility of modeling deformable structures in a rigid body framework and propose several enhancements to improve the convergence of collision resolution, including a hybrid time integration scheme to separately handle at rest contacts and dynamic collisions. Finally, we extend the impulse‐based LS‐DEM to include arbitrarily shaped topographic surfaces and exploit its algorithmic advantages to demonstrate the feasibility of modeling realistic behavior of granular flows. The new formulation significantly improves the performance of dynamic simulations by allowing larger time steps, which is advantageous for observing the full development of physical phenomena such as rock avalanches, which we present as an illustrative example. [ABSTRACT FROM AUTHOR]

Geologic hazards affect the community of Achoma, in Peru's Colca Canyon. Building on a rockfall hazard characterization study, this article engages the principles of participatory mapping and user-centered design for the tailoring of hazard maps to the context. Two workshops were conducted with community members to gauge their perceptions of sample maps, preferences for design elements, and potential uses of maps, and to refine accuracy of map features. Each workshop consisted of three activities in which participants marked up and discussed sample maps. The activities focused on (1) basemap preferences and locally relevant features, (2) intelligibility of rockfall hazard information, and (3) intelligibility of color schemes and representations of hazard severity ratings. The outcomes of the workshops were used to inform design updates for a final hazard map, which was provided to community members and local officials. The study identified many design preferences that were similar to those found in prior studies and expanded the scope of participatory and user-centered design research in hazard mapping, which has mostly been conducted in the Global North. [ABSTRACT FROM AUTHOR]

Landslides represent a major problem in human activities, especially in the proximity of cities or infrastructure. In this paper, we present the peculiar case of Pietracamela, Italy. Pietracamela is a small village located in the Central Apennines, a few kilometers north of the Gran Sasso Mountain. The peculiarity of the case study is the fact that the village is simultaneously affected by two different types of slope instabilities. The southwest sector, representing the historical part of the village, has been affected by large rockfalls generated from the "Capo le Vene" cliff located in the south of the village. The northeastern sector of the village represents the most recent urbanized area and is involved in a deep-seated landslide that, in the last decades, has damaged buildings and infrastructure. In this context, we have used two different types of remote sensing techniques to study the two phenomena. The rockfall area has been surveyed through the use of an Unmanned Aerial Vehicle (UAV) that allowed the definition of main joint sets and the volume of blocks associated with the most recent (2011) rockfall event. Three main joint sets have been highlighted, which are responsible for the failure of the "Capo le Vene" cliff. The volume of blocks that failed during the last rock failure in 2011 ranged from a few to 1500 m3. The deep-seated landslide has been studied by analyzing borehole data and 20 years of InSAR data from ERS1/2, ENVISAT, COSMO-SkyMed, and SENTINEL-1. It has been highlighted by InSAR analysis that the northeast sector of the village shows a perfectly linear displacement trend that generates movements up to about 230 mm (about 1 cm/year). [ABSTRACT FROM AUTHOR]

Understanding the triggering factors leading to rockfall is essential in managing their risk to transportation infrastructure. Precipitation and freeze-thaw (FT) are widely studied rockfall triggers, but developing reliable, quantitative methods to forecast rockfall in response to weather events remains challenging. Terrestrial laser scanning (TLS) is a powerful tool for high-accuracy modeling of rock slopes, but the frequency of scanning is often too low to correlate rockfall behavior with weather events or seasonal trends. We conducted a TLS campaign between 2017 and 2022 in Glenwood Canyon, Colorado, to investigate the seasonal variability in rockfall triggering and conditioning mechanisms. A total of 44 scans were collected over 5 years and were processed to allow for consistent detection of rockfalls larger than 0.0036 m3 in volume. Meteorological variables relating to precipitation, snowpack, and temperature were modeled using the National Weather Service SNODAS product and were used to complete an exploratory analysis of the correlation of various weather indices with rockfall rate over time. It was found that the short-term sum of liquid precipitation and snowmelt (averaged over the scanning interval or the max single-day total) was a strong predictor of rockfall volume rate between 2018 and 2020, especially in the spring and summer months; a linear model of max daily liquid was able to explain 65% of the variance (R2adj) in rockfall volume rate in March through August. This implicates springtime snowmelt and rain-on-snow events as strong predictors of rockfall at the study site. We interpret these observations to indicate that snowmelt and rainfall are acting to trigger blocks that have been conditioned (destabilized) over the preceding winter. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Architecture & Civil Engineering is the property of Chang'an Daxue Zazhishe and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Insufficient geological research and a limited understanding of ground conditions during the design phase often led to slope failures and subsequent repair costs. This issue is notable in the 104 km Silchar-Haflong National Highway in Assam, India, located in the northwestern part of the Assam-Arakan folded mountain range. Over 158 slope failures have occurred due to various geo-climatic factors aggravated by human activities. A comprehensive engineering geological investigation was conducted on a 25 km section, using techniques like RMRbasic, SMR, Qslope to assess slope conditions at several locations. Stability analyses were carried out using finite element numerical method for both dry and saturated conditions, revealing four potentially unstable slopes (L3, L5, L7, and L8). Critical SRF values ranged from 1.15 to 1.72 for dry conditions, while they varied from 0.95 to 0.98 for saturated conditions. The study also examined rockfall analysis for slope L7, considering parameters such as translational velocity, rebound height, kinetic energy, and travel distance. The findings indicated a potential for falling blocks to reach the road and pose a significant risk. The study emphasizes the need for implementing appropriate measures to address informal slope excavation, or else there is a likelihood of increased frequency and scale of rainfall-triggered roadside slope failures. [ABSTRACT FROM AUTHOR]

Assessment of landslide hazards often depends on the ability to track possible changes in natural slopes. To that end, historical air photos can be useful, particularly when slope stability is compromised by visible cracking. Undocumented landsliding rejuvenates a paleo-landslide on a busy motorway connecting Jerusalem to a small Jewish settlement. Recently, a plan for broadening the motorway was approved, and we were asked to study the hazards of the road by Israeli NGOs and Palestinian residents of the area. We captured high-resolution topography around the unstable slope using drone-borne photogrammetry and LiDAR surveys. The modern data allow us to analyze historic air photos and topo maps to assess the level of sliding prior to and during modern landscaping. Our results indicate horizontal offsets of ~0.9–1.8 m and vertical offsets of 1.54–2.95 m at selected sites. We next assess the possible role of anthropogenic versus natural factors in compromising slope stability. We analyze monthly rain records together with seismic catalogs spanning several decades. Shortly after the motorway construction in 1995, a January 1996 rainstorm triggered a massive rockfall. The rockfall blocked traffic with up to 4 m-diameter boulders. We found that while a certain level of rain is a necessary condition for mobilizing the rock mass, it is the anthropogenic intervention that caused the rockfall in this site. We conclude that the recent plan for broadening the motorway jeopardizes the lives of vehicle passengers and the lives of future residents should the development materialize. [ABSTRACT FROM AUTHOR]

Drainage tunnel stability is crucial for engineering project safety (e.g., mine engineering and dams), and rockfall events and water release are key indicators of drainage tunnel stability. To address this, we developed a monitoring system to simulate drainage tunnel intrusions based on distributed acoustic sensing (DAS), and we obtained typical characteristics of events like rockfall events and water release. Given the multitude of DAS signal feature parameters and challenges, such as high-dimensional features impacting the classification accuracy of machine learning, we proposed an identification method for drainage tunnel intrusion events using principal component analysis (PCA) and neural networks. PCA reveals that amplitude-related parameters—amplitude, mean amplitude, and energy—significantly contribute to DAS signal classification, reducing the feature parameter dimensions by 54.8%. The accuracy of intrusion event classification improves with PCA-processed data compared to unprocessed data, with overall accuracy rates of 79.1% for rockfall events and 72.7% for water release events. Additionally, the artificial neural network model outperforms the Bayesian and logistic regression models, demonstrating that ANN has advantages in handling complex models for intrusion event classification. [ABSTRACT FROM AUTHOR]

Passive seismic monitoring (PSM) is emerging as a tool for detecting rockfall events and pre‐failure seismicity. In this paper, the potential of PSM for rockfall monitoring is assessed through a case study carried out in Gros‐Morne, Eastern Québec, in a region with prominent roadside cliffs, where more than 500 fallen rocks are found on the main regional road each year. The proposed method relies on using sensitive STA‐LTA windows to detect a very large number of seismic events and build a comprehensive catalog. In total, more than 70,000 seismic events were detected over one year. Gaussian mixtures are used to partition the data set. Based on visual inspection of the data, a main working hypothesis is that the seismic events can be clustered into three groups. After analyzing the spatio‐temporal distribution of the events in each group, we find that the events of one cluster can be associated with anthropogenic activity. The frequency of occurrence of the events of the different clusters and their link with meteorological data is also examined through a regression exercise, to assess the importance of the meteorological variables as explanatory variables. The results allow us to postulate on the physical origins of the signals in the different clusters, attributing them to rockfall activity and wind‐induced seismic noise. Plain Language Summary: This study explores the use of passive seismic monitoring (PSM) as a method to detect and track rockfall events, focusing on an area in Eastern Canada, where more than 500 rockfalls reach the main regional road each year. We utilized an automated seismic event detection algorithm to identify over 70,000 seismic events in a one‐year period. By analyzing these events with machine learning, we discovered patterns that allowed us to group the events into three categories. One of these groups is linked to human activity, while the other two are influenced by natural factors such as rainfall, strong temperature changes, and wind speed. We interpret the origins of the signals in the latter two groups as rock impacts during rockfalls for one, and strong winds hitting the rock cliff for the other. Our research shows that PSM, coupled with machine learning, is a powerful technique for understanding geomorphological dynamics at a small timescale. Key Points: We use feature engineering to automatically analyze seismic signals measured on a cliff with frequent rockfallsClustering proves useful to distinguish signals with different waveforms and frequency contentAnalysis of the relationships between meteorological variables with each cluster enables their physical interpretation, from geomorphological dynamics to anthropic activity [ABSTRACT FROM AUTHOR]

Seismic instruments placed outside of spatially extensive hazard zones can be used to rapidly sense a range of mass movements. However, it remains challenging to automatically detect specific events of interest. Benford's law, which states that the first non‐zero digit of given data sets follows a specific probability distribution, can provide a computationally cheap approach to identifying anomalies in large data sets and potentially be used for event detection. Here, we select vertical component seismograms to derive the first digit distribution. The seismic signals generated by debris flows follow Benford's law, while those generated by ambient noise do not. We propose the physical and mathematical explanations for the occurrence of Benford's law in debris flows. Our finding of limited seismic data from landslides, lahars, bedload transports, and glacial lake outburst floods indicates that these events may follow Benford's Law, whereas rockfalls do not. Focusing on debris flows in the Illgraben, Switzerland, our Benford's law‐based detector is comparable to an existing random forest model that was trained on 70 features and six seismic stations. Achieving a similar result based on Benford's law requires only 12 features and single station data. We suggest that Benford's law is a computationally cheap, novel technique that offers an alternative for event recognition and potentially for real‐time warnings. Plain Language Summary: Natural hazards, such as debris flows and landslides, pose a significant threat to the exposed communities. Seismic instruments are seen as effective tools for detecting these hazardous processes and may be used in early warning systems. However, the difficulty lies in identifying the events of interest concisely and objectively. Our study explores Benford's law, describing the relative occurrence of the first non‐zero digit. We collected seismic data generated by various hazard events and compared the observed first‐digit distribution with their agreement with Benford's law. We found seismic signals of debris flows follow Benford's law during the run‐out phase, while ambient noise do not. Our detector, based on Benford's law and designed for debris flow, which is a computationally cheap and novel model, performs similarly to a machine learning algorithm previously used in the study site. Our work illustrates a new approach to detecting events and designing warning systems. Key Points: The first‐digit distribution of seismic signals generated by debris flows follows Benford's lawWhen Benford's law appears, seismic signals tend to increase exponentially and converge to a power law distribution with exponent oneA computationally cheap and novel detector based on Benford's law is developed for debris‐flow events [ABSTRACT FROM AUTHOR]

The Zhala hydropower station plant was under the threat of rockfalls induced from a high slope, especially in rainy seasons. This paper proposes an innovative protection structure consisting of a pervious concrete wall and a sand cushion to protect against rockfall impact as well as discharge surface runoff. Laboratory test results show that the peak impact force of the rockfall decreases with decreasing rockfall mass and impact velocity, together with increasing cushion thickness and rockfall sphericity. The most sensitive factor influencing the peak impact force is rockfall sphericity, followed by impact velocity, rockfall mass, and cushion thickness. Based on the sensitivity of influencing factors, a method of calculating the rockfall peak impact force was established by dimensional analysis. Furthermore, a full-scale test was conducted to investigate the feasibility of this structure; test results indicate that an increased rockfall mass results in increased peak impact force, impact stress, and displacement of the pervious concrete wall. By placing a sand cushion in front of the pervious concrete wall, the peak impact force of rockfall and the maximum displacement of the wall are decreased by 70% and 65%, respectively. Meanwhile, the proposed calculation method has good reliability for evaluating the practical rockfall impact force, compared with four classical calculation methods. After the buffering effect of the sand cushion, the impact stress distribution on the pervious concrete wall can be characterized as a bell shape, with high magnitude at the impact point and low magnitude on the sides. [ABSTRACT FROM AUTHOR]

The 2022 Paktika earthquake (moment magnitude: 6.2) occurred on June 22, 2022, near the border between the Khost and Paktika Provinces of Afghanistan, causing heavy damage and casualties in Paktika Province. This study evaluated the crustal deformation and associated strong motions induced by the Paktika earthquake. Crustal deformations were determined using the Differential Interferometric Synthetic Aperture Radar (DInSAR) technique and three-dimensional finite element method (3DFEM) and the results were compared. The permanent ground displacements obtained from the DInSAR and 3D-FEM analyses were similar in terms of amplitude and areal distribution. Strong motions were estimated using the 3D-FEM with and without considering regional topography. The estimations of maximum ground acceleration, velocity, and permanent ground deformations were compared among each other as well as with those inferred from failures of some simple structures in the Spera and Gayan districts. The inferred maximum ground acceleration and velocity from the failed adobe structures were more than 300 Gal and 50 cm/s, respectively, nearly consistent with the estimates obtained using empirical methods. The empirical method yielded a maximum ground acceleration of 347 Gal, whereas the maximum ground velocity was approximately 50 cm/s. In light of these findings, some surface expressions of crustal deformations and strong ground motions, such as failures of soil and rock slopes and rockfalls, have been presented. The rock slope failures in the epicentral area were consistent with those observed during various earthquakes in Afghanistan and worldwide. [ABSTRACT FROM AUTHOR]

We conducted a phytosociological survey of pioneer shrub and shrub-wood (brushwood) communities on river banks at the contact of gravel bars and rockfall, slope debris or colluvium in the spring area of the Nadiža River, in the gorge of the Soča River between Srpenica and Kobarid (Log Čezsoški and Magozd), in the Tolminka valley, and in certain other locations in the hills of western Slovenia. We identified a successional sequence of two grey willow and hop hornbeam communities, which we classify into the associations Salicetum eleagno-appendiculatae (Salicion eleagno-daphnoidis) and Peucedano verticillari-Ostryetum carpinifoliae (Fraxino orni-Ostryion). Both are indicators of natural river banks that have not been artificially stabilized. We expanded the knowledge of hop hornbeam communities in the pre-Alpine–northern-Dinaric part of Slovenia with a description of a new association Scopolio carniolicae-Ostryetum carpinifoliae. Its sites are characterised by slightly moist soil, and its stands by a higher proportion of species of the alliance Tilio-Acerion. [ABSTRACT FROM AUTHOR]

Rock shed is an effective protection measure against rockfall. To investigate the influences of falling rock’s shape and impact angle on the impact effect of the cushioned rock shed, a modeling approach for a rock shed with a cushion layer using PFC-FLAC. The granular cushion is modeled as an aggregate of discrete non-cohesion particles, while the concrete plate and the beam are modeled as zones. The falling rock with different sphericities and impact angles is modeled as a rigid assembly. The numerical model is validated by comparing the simulation results with experimental and numerical results from previous literature. This model is applied to analyze the effects of rock shape and impact angle on the dynamic interaction effects between falling rock and cushioned rock shed, including the impact force, transmitted bottom force, penetration depth, and plate deflection. The numerical results show that the variation in the falling rock’s shape has different effects on the falling rock with different impact angles. These findings could support rock shed design by revealing the limitations of the assumptions in the past research, which may result in unsafe rock sheds for some rockfall cases.

The impact effects of falling rocks on sand–reinforced concrete slab composite protective structures involve several factors. Among them, the existing codes are unable to consider the effect of rockfall shape and the angle of contact between the rockfall and the object on the impact force as well as the depth of penetration. Based on extensive field investigation, this paper proposes a shape factor to simplify the rockfall into an ellipsoid and determines the shape and dimensions of the rockfall by three-dimensional axis length. Besides, a coupled SPH-FEM numerical calculation model is established and validated through comparison with a large-scale outdoor test of a rockfall impact protection structure. Finally, the effects of rockfall shape and impact angle on the symbolic parameters including impact force, impulse and energy in the impact process are revealed. The findings indicate that the maximum force and displacement of the midpoint of the bottom of the reinforced concrete slab have relative errors within 5.0 % when compared to the model test, confirming the precision of the models discussed in this paper. For the same rockfall, the peak force decreases with the impact angle increasing; taking the same volume of spherical rockfall as the reference, under the same rockfall pattern, the peak impact force and impulse amplification factor decreases with the increase in contact attitude angle. Additionally, the scaling effect becomes more pronounced when the shape factor of the rockfall is smaller; under the same shape factor, the impact depth of the cushion layer is the smallest when the attitude angle is 45°, and the maximum when the impact angle is 90°; the SPH-FEM coupling algorithm could reasonably reproduce the pit-forming process of sand and soil, and it is very effective in simulating the flow effect of soil particles under impact.

In this study, a comprehensive assessment of disaster hazards in Elazığ province, where the Eastern Anatolian Fault Zone passes through, was conducted. Hazard maps for earthquakes, floods, landslides, rockfalls, avalanches, desertification, and erosion were integrated to create a multi-hazard map. Various methods, such as the Analytic Hierarchy Process (AHP) and machine learning models, including the Random Forest algorithm, were employed to assess the severity and probability of exposure for each hazard type. Independent variables, including VS30, liquefaction potential, Digital Elevation Model (DEM)-derived data, and climatic data, were selected based on relevant literature and the study area. For earthquake and erosion hazards, intuitive models were used due to the absence of a single dependent variable. The desertification map was obtained from the Ministry of Environment, Urban Planning, and Climate Change. The Random Forest model was used for other disaster hazard maps. All hazard maps were combined using a hierarchical approach with the Weighted Overlay tool. The study generated a spatial synthesis and database intended to offer proactive insights into disaster preparedness, optimizing resource allocation, and expediting recovery efforts post-disaster within the Elazığ Province. Its primary objective is to provide assistance to local authorities and emergency response teams. In the province, a significant portion of urban settlements and the majority of rural areas face high earthquake hazards. Floods pose a considerable risk, particularly in low-lying areas downstream of numerous dams scattered across the province, as well as at the confluence points of seasonal riverbeds. The hazard of landslides is high in the rugged areas along the EAF and in steep terrains eroded by rivers. Moreover, rock falls occur more frequently in mountainous areas along the Hazarbaba-Akdağ axis due to erosion and physical dissolution. Erosion and desertification represent significant slow-moving hazards, with erosion intensifying on steep slopes and barren lands, while desertification notably affects Baskil and its surrounding low-lying areas in the western part of the province. Considering multiple hazards, areas with concentrated settlements and economic activities such as Elazığ, Baskil, Kovancılar, Karakoçan, and Behrimaz plains are categorized as very high and high-risk zones.

Pile-slab rockfall retaining wall is a novel passive protective structure designed to intercept falling rocks. It is made up of cantilever piles, pile-intermediate slabs, and cushion layers. This structure features strong terrain adaptability , small footprint, and high interception height, making it applicable in high-risk rockfall areas. However, due to the lack of detailed reports on the ultimate bearing capacity of cantilever piles, guidance for engineering practice is unavailable. This paper first proposes a reasonable thickness for the cushion layer based on the characteristics of the propagation of falling rock impact forces. Then, according to the stress and deformation characteristics of the pile body, theoretical calculation methods of the internal forces and displacements of the pile body are derived using the elastic support cantilever beam model and the Winkler elastic foundation beam model, enabling the automatic determination of design parameters for cantilever pile under falling rock impact. The results indicate that for a rockfall with a diameter of 2 m, impact height of 7.0 m, impact velocity of 10 m/s, and a cushion layer thickness of 1.5 times the rockfall diameter, a double-row triple-limb steel-reinforced 1.5 m × 1.2 m cantilever pile can withstand an impact force of 2.51 × 106 N and impact energy of 565 kJ. For cases with higher falling rock impact energy, it is recommended to prioritize enhancing the bending resistance of the retaining wall. This research provides a scientific basis for disaster prevention and reduction in rockfall-prone areas in the western mountainous regions of China.

The threat of rockfall impacting bridges in mountainous areas poses a great risk to the safety of passing trains. This study delves into the dynamics of rockfall impact and its implications on the interaction between train vehicles and bridges. Leveraging LS-DYNA, this study first captured the force–time history of rockfall impact on bridge structures. Subsequently, there was a comparison with the impact forces generated at various speeds with those predicted by established formulas, validating the accuracy of simulations. Employing BANSYS software, the dynamic responses of both bridge structures and the vehicle–bridge coupling system to falling rocks were analyzed. The investigation encompassed parameters such as impact speed, position, and train location. The findings reveal that escalating impact speeds correlate with increased average and maximum impact forces from falling rocks. Notably, the average impact force does not linearly correspond with rock speed and often exceeds values calculated by conventional formulas. Impact position minimally affects maximum impact force, yet alterations in position prolong impact duration, consequently reducing average impact force. Rockfall-induced impacts precipitate notable spikes in train lateral acceleration, lateral wheelset force, wheel unloading rate, and derailment coefficient, albeit with a comparatively lesser impact on vertical acceleration. Increasing impact speed and altering position intensifies the vehicle’s response, particularly when the train is in close proximity to the impact site. [ABSTRACT FROM AUTHOR]

Translation abstract Assessment of rockfall protection systems for low‐energy areasCurrent studies on the subject of rockfall protection structures generally focus on medium to high impact energies. Systems with an energy absorption capacity of up to approx. 10,000 kJ already exist for flexible rockfall protection fences. In many regions, however, the risk of falling rocks and boulders is often associated with significantly lower energies. This is particularly the case along infrastructure such as transport routes. The Bavarian State Construction Administration therefore uses wire fences as roll‐off protection, which explicitly cover the area with an energy absorption capacity of up to 60 kJ. The wire fences consist of commercially available components stored by specialist companies and were tested by the Central Office for Engineering Structures and Georisks (ZIG) at a height of 2.30 m in a quarry near Passau. During the tests, the University of Innsbruck, Geotechnics Department, measured the relevant cable forces and evaluated the kinematics of the test blocks using video analyses. The article describes the construction details of the wire fence, the boundary conditions of the 1 : 1 load tests, the evaluation of the measurement data and the further findings for the design. In addition, the temporal path of the force is analysed when determining the design actions on anchors and foundations. [ABSTRACT FROM AUTHOR]

Rockfall poses a formidable threat to the ongoing fast-paced construction of large-scale projects in uninhabited areas in high mountain valleys. In this study, an optimization method for arranging passive nets on high and steep slopes was presented to mitigate the threat from rockfalls. This method diverges from the conventional method of subjectively arranging passive nets along the perimeter of protected regions (due to its emphasis on cost considerations), in which the quantitative appraisal of rockfall movement characteristics and interception rates is frequently omitted, consequently failing to comprehensively ensure transportation routes and temporary construction sites. The methodology encompasses the acquisition of terrain data by unmanned aerial vehicles (UAVs), identification of rockfall sources based on UAV point clouds, quantitative assessment of rockfall hazards using a 3D probabilistic model, and optimization of the layout of passive nets based on the assessment results. The aim of the optimization of passive nets is to quantitatively assess the cost–effect relationship of passive nets, accounting for construction feasibility, interception potential, and likelihood of successful rockfall interception. We applied this method to the Feishuiyan slope in southwest China as an example, and the results demonstrated an enhanced interception rate of 99% and cost reduction by a factor of three relative to the original scheme. This innovative approach could enhance rockfall mitigation in high and steep areas, providing a viable strategy for future prevention efforts in these areas. [ABSTRACT FROM AUTHOR]

Rockfalls are frequent geodisasters, characterized by gravity driven downslope movement of a solid mass of rock. The kinematics of rocks is heavily dependent on their shape, which leads to a competition between sliding, bouncing, and rolling, and thus to a large variation in runout distances. Numerical studies using simplified round particles cannot fully reproduce the complex motion resulting from the interaction with the terrain, while more realistic models so far had most of their application limited to case studies, thus systematic investigations into block shape are largely missing. In this study, we systematically investigate the effect of rock shape and initial orientation on the course and runout of rockfall events by means of a two-dimensional polygonal discrete element simulation with soft contacts. We analyze the runout behaviour and first impact on the ground for six different block geometries and 91 different initial orientations for each geometry. The obtained results quantify the effect of particle angularity and elongation and show that the kinematic and dynamic observables of rockfall events can not be expressed as an explicit function of the initial orientation but have to be treated in a statistical way. We find that the expectation values and standard deviations for the maximum runout distance and the normal restitution coefficient show a clear shape dependence and saturate with increasing particle roundness, while for the impact angle and tangential restitution coefficient, we notice stronger differences with respect to particle elongation. [ABSTRACT FROM AUTHOR]

Distributed acoustic sensing (DAS) using fiber-optic cables has potential for landslide and rockfall monitoring along linear infrastructure but faces challenges for accurate seismic source localization due to signal nonuniformity and attenuation during propagation. This limits the applicability of traditional seismic location methods with DAS. We present a novel computer vision–based approach to overcome these limitations. Field experiments simulating landslide quakes and rockfall impacts were conducted near dedicated DAS arrays to validate the method. Results demonstrate the computer vision technique outperforms short-to-long-term average ratio and cross-correlation algorithms in both location accuracy and constraint of seismic sources, with locations also agreeing well with a colocated nodal seismic array. Key factors influencing performance include the type of signal processing used on the DAS data and cable array geometry. The envelope function best handled noise while L-shape and parallel dual-cable geometries proved most effective. Overall, this computer vision method provides an improved solution for seismic source location of landslides and rockfalls monitored by DAS networks, enhancing safety along vulnerable linear infrastructure like transportation corridors through mountainous terrain. [ABSTRACT FROM AUTHOR]

The estimation of rockfall frequency for the quantitative assessment of rockfall hazard is challenging when there are not records of previous events. The aim of this study is to investigate the correlation between the rockfall frequency and the geometry of the overhanging rock blocks, at rocky slopes. The investigation takes place for seven rocky slopes along a coastal road in Northern Spain, and it is based on 15 years of rockfall data. A field survey of these slopes took place between May and June 2022, using a terrestrial laser scanner as well as ground and aerial photogrammetry from UAVs, in order to build three-dimensional digital models. Then, the geometrical attributes of the existing overhanging rocks were measured on the models. The surface area and the width of the latter were calculated. The correlation between the rockfall frequency and the sum of the overhanging areas at each slope was assessed. A good linear correlation was indicated between the normalized per slope area number of rockfalls and total overhang area (R2 = 0.9013) and between the respective normalized per unit of road length parameters (R2 = 0.9594). The magnitude-frequency relationship for the rockfall events that occurred at the seven slopes follows a power law distribution with exponent −0.65. [ABSTRACT FROM AUTHOR]

Debris flow activity in the Geysernaya River basin was mapped. Large-scale debris flow processes due to the collapse of fragments of the valley's left wall were observed in this area three times over the past 40 years. Three independent debris flow areas of the river basin were identified and described: the upper reaches of the river, the Levaya Geysernaya basin; the middle reaches of the river, below the dammed lake that formed in 2014; and the lower downstream part, below the dammed lake that existed in 2007–2014. Debris flow processes are typical of most tributaries of the Geysernaya River. Moreover, debris flows can be aseasonal in the left tributaries, because they are formed under constant heating and active gas–hydrothermal influence within the thermal fields. The landslide dam formed in 2014 is resistant to erosion, and an independent outburst of the dammed lake is unlikely. With further erosion of the 2007 dam and expansion of the breach in the dam body, collapse of its sides and debris flow in the lower part of the Geysernaya River valley should not be ruled out. Risks of rockfall, landslide, and debris flow processes, most likely on the left wall of the valley, should be taken into consideration in planning the development of recreation facilities. [ABSTRACT FROM AUTHOR]

Laboratory work was performed to investigate the influence of rock morphological parameters on the kinematic characteristics of rockfalls. A handheld laser scanner was used to collect the dense three-dimensional (3D) point clouds for the reconstruction of the rock samples. Five morphological parameters were determined based on the 3D reconstruction to accurately quantify the shape of rock samples. The trajectory of rock samples was recorded by a high-speed camera, and particle image velocimetry (PIV) was employed to extract the kinematic parameters of the rock samples. The correlation between the morphological parameters and kinematic parameters of rock samples was analyzed, and the results show that the sphericity and volume filling rate of pebbles have a significant influence on the velocity and final longitudinal distance of rockfall. However, no clear correlation between the morphological parameters and the lateral travel distance was observed from the present tests. [ABSTRACT FROM AUTHOR]

Over three-quarters of Taiwan's landmass consists of mountainous slopes with steep gradients, leading to frequent rockfall hazards that obstruct traffic and cause injuries and fatalities. This study used Google Alerts to compile internet news on rockfall incidents along Taiwan's highway system from April 2019 to February 2024. The locations of these rockfalls were geolocated using Google Earth and integrated with geographical, topographical, environmental, geological, and socioeconomic variables. Employing machine learning algorithms, particularly the Random Forest algorithm, we analyzed the potential for rockfall hazards along roadside slopes. The model achieved an overall accuracy of 0.8514 on the test dataset, with a sensitivity of 0.8378, correctly identifying 83.8% of rockfall locations. Shapley Additive Explanations (SHAP) analysis highlighted that factors such as slope angle and distance to geologically sensitive areas are pivotal in determining rockfall locations. The study underscores the utility of internet-based data collection in providing comprehensive coverage of Taiwan's highway system, and enabled the first broad analysis of rockfall hazard susceptibility for the entire highway network. The consistent importance of topographical and geographical features suggests that integrating detailed spatial data could further enhance predictive performance. The combined use of Random Forest and SHAP analyses offers a robust framework for understanding and improving predictive models, aiding in the development of effective strategies for risk management and mitigation in rockfall-prone areas, ultimately contributing to safer and more reliable transportation networks in mountainous regions. [ABSTRACT FROM AUTHOR]

Accurate rockfall modeling is crucial for evaluating rockfall hazards and requires consideration of several inputs data, including parameters that control boulder trajectories and source areas. Inaccurate definitions of source areas can lead to unrealistic representations of the rockfall process. In this study, we analyze how different approaches used to define source areas can affect the accuracy of rockfall modeling. The island of El Hierro (Canary Islands, Spain) is selected due to its geological and geomorphological characteristics, as well as the socio-economic importance of rockfalls on the island. To assess rockfall source areas, three different approaches were considered, ranging from situations with limited data availability to scenarios with many topographic, geological and geomorphological information. A morphometric firstly approach establishes a slope angle threshold above which block detachment zones are considered. For the second approach, we have employed a statistical method to identify rockfall source areas, using Empirical Cumulative Distribution Functions (ECDF) of slope angle values. The third method was a probabilistic modeling framework that applies a combination of multiple multivariate statistical classification models. These models use the mapped source areas as a dependent variable, as well as a set of thematic information as independent variables. The source area maps obtained from the three methods were used as inputs for a rockfall runout model, to establish a classification of rockfall susceptibility areas. One of the main outcome of the rockfall modeling simulations on El Hierro is the rockfall trajectory counts maps, showing areas prone to rockfalls. These maps indicate the probability of a given pixel being affected by a rockfall event. Two classification approaches were applied to generate the probabilistic susceptibility maps: unsupervised and supervised statistical methods by using distribution functions. The unsupervised classification only employs as input the raster map of the rockfall trajectory counts. In contrast, the supervised classification requires additional data on the areas already affected by rockfalls. Finally, six susceptibility maps are developed and compared to highlight the influence of source areas definition on the distribution of rockfall trajectories. [ABSTRACT FROM AUTHOR]

We performed a passive seismic monitoring of the La Praz ∼14,000 m3 unstable slope (French Alps) spanning over 10 years. During the last 6 months prior to collapse, we detected a clear 24% decrease in the slope's fundamental resonance frequency, f0, caused by a reduction in overall rock mass stiffness. The combined study of f0 and slope deformation suggested the alternating importance of sudden brittle failure processes versus more ductile phases with possible sliding. Seismic monitoring revealed slope damage that remained ambiguous or undetected with ground surface deformation monitoring, and highlighted critical periods with intense damage. Only some of these critical damage periods could be related to clear external forcing factors such as intense rainfall episodes. These new insights into rock slope's structural condition at depth represent an asset for future monitoring systems. Surface deformation and passive seismic stiffness tracking combined could reveal active slopes with ongoing damage processes. Plain Language Summary: Forecasting the time of rockfalls is of critical importance for risk mitigation operators in order to preserve the safety of persons and the integrity of infrastructure. Most monitoring systems are based on ground deformation measurements, which may fail when the surface motion does not accurately reflect changes in slope stiffness with time. In this work, we used a seismic sensor that passively recorded ground vibrations on top of a ∼14,000 m3 unstable slope. We detected a significant decrease in the slope's first resonance frequency (−24%) during the 6 months preceding complete collapse. We also revealed details of slope damage processes acting within the slope, showing sudden breakage phases alternating with smoother deformation and sliding phases. These processes would not have been suspected with slope deformation monitoring alone. The use of a new parameter that combines passive seismic tracking and surface deformation measurements could help revealing active slopes with ongoing damage processes. This inovative approach represents an asset for future practical rock slope monitoring. Key Points: We observed a 24% decrease in rock slope fundamental frequency during the 6 months preceding a ∼14,000 m3 collapseNew insights into slope degradation processes revealed the alternate control of two damage regimes with contrasting rateResults revealed slope damage phases that would not have been suspected on the basis of slope deformation monitoring alone [ABSTRACT FROM AUTHOR]

Forestry is facing an unprecedented challenging time. Due to climate change, major tree species, which until recently fulfilled major ecosystem services, are being lost and it is often unclear if forest conversion with other native or nonnative tree species (NNT) are able to maintain or restore the endangered ecosystem services. Using data from the Austrian Forest Inventory, we analysed the current and future (2081-2100, RCP 4.5 and RCP 8.5) productivity of forests, as well as their protective function (avalanches and rockfall). Five different species change scenarios were considered for the replacement of a tree species failing in the future. We used seven native tree species (Picea abies, Abies alba, Pinus sylvestris, Larix decidua, Fagus sylvatica, Quercus robur and Quercus petraea) and nine NNT (Pseudotsuga menziesii, Abies grandis, Thuja plicata, Pinus radiata, Pinus contorta, Robinia pseudoacacia, Quercus rubra, Fraxinus pennsylvanica and Juglans nigra). The results show that no adaptation would lead to a loss of productivity and a decrease in tree species richness. The combined use of native and NNT is more favorable than purely using native species in terms of productivity and tree species richness. The impact of the different species change scenarios can vary greatly between the different environmental zones of Austria (Alpine south, Continental and Pannonian). The Pannonian zone would benefit from the use of NNT in terms of timber production. For the protection against avalanches or rockfall in alpine regions, NNT would not be an advantage, and it is more important if broadleaved or coniferous trees are used. Depending on whether timber production, protective function or tree species richness are considered, different tree species or species change scenarios can be recommended. Especially in protective forests, other aspects are essential compared to commercial forests. Our results provide a basis for forest owners/managers in three European environmental zones to make decisions on a sustainable selection of tree species to plant in the face of climate change. [ABSTRACT FROM AUTHOR]

In this study, rock stability has been assessed to pinpoint the critical factors affecting slope instability. The discontinuity data collected during the field surveys was evaluated using stereograph projection. Bai Hassan, Mukdadiya, and Injana Formations that were exposed in the research region show slope collapses, ranging in severity from most to least in terms of secondary toppling and rock fall. The characteristics of the rock discontinuities determine the kind and extent of hazards. According to this study, warning signs and fencing should be used to prevent people from walking along the edges of the slopes in the Bajalia anticline and the areas around to alert them of potential failure threats. [ABSTRACT FROM AUTHOR]