Search Results (288)

Stone-built cultural heritage sites face significant threats from weathering and environmental stress, leading to structural damage or even total collapse. Consequently, robust monitoring and conservation strategies are essential. This study introduces the Monument Rockfall Risk Assessment (MRRA), a heuristic prioritization framework designed for the rapid ranking of detachment risks in monumental contexts. The MRRA was tested on the Piazzale Michelangelo Ramps in Florence (Italy), which are prone to rockfall hazard due to the presence of unstable blocks made of Pietraforte sandstone. The methodology employs a qualitative-heuristic risk rating approach, considering factors such as joint characteristics, centre of gravity location, and estimated kinetic energy of falling blocks. Susceptibility, vulnerability, and elements at risk were evaluated for each unstable block to calculate a relative risk index, which was then aggregated to determine the overall risk of each coping. The methodology was applied to a recent rockfall event that occurred in 2020 and compared with expert judgement to evaluate the model’s performance in identifying criticalities. Since decisions on defence and restoration works depend on geomechanical, social, and economic factors, this study explores an approach to establish optimal risk rating thresholds for the MRRA methodology, balancing false and missed alarms. Full article

The influence of impact configuration and block shape on rockfall rebound behavior has been highlighted in numerous experimental studies. To further investigate these effects, an experimental campaign was conducted using rigid elliptical-disk blocks, allowing the simultaneous examination of block geometry and impact configuration under controlled conditions. The experimental setup was inspired by existing analytical approaches that employ elliptical geometries to describe rebound mechanics and to provide a more detailed interpretation of the parameters governing impact response. The results show that coefficients of restitution exhibit substantial scatter and do not display systematic trends with respect to the geometric aspect ratio of the elliptical disks (a/b ≈ 1.25–2.0), within the testing range of this experiment. Instead, rebound behavior is primarily controlled by impact configuration, as described by the orientation of the major axis and the impact angle. The following two distinct impact types were identified: instantaneous and rolling, associated with different responses. The experimental data were further used to assess existing analytical models, revealing limited quantitative agreement due to the idealized assumptions in their formulation. Overall, the study demonstrates that rebound response in rockfall processes is strongly configuration-dependent, emphasizing the need for modeling approaches that explicitly account for impact configuration and contact geometry. Full article

Studying the slumping disintegration, movement speed, impact intensity, accumulation characteristics, and energy conversion laws of tower-column unstable rock masses (TCURM) is crucial for high-altitude rockfall hazard risk evaluation. Existing PFC-based rockfall simulations rarely target the unique “top-hard-bottom-weak” structural characteristics of TCURM and lack in-depth integration of on-site monitoring videos to verify dynamic evolution processes. Taking the large-scale collapse of W12^# unstable rock mass at Zengziyan, Jinfo Mountain in Chongqing as an example, a combination method of orthogonal test and PFC^3D discrete element simulation is used. Mesoscopic parameters are calibrated via comparison with on-site video and investigation data, accurately reproducing the entire slumping disintegration process and revealing its dynamic characteristics. Results confirm the simulation is basically consistent with field data, verifying the model and parameter rationality. The total duration from instability to stagnation is 121 s (15 s to impact the secondary steep cliff base, 106 s for debris accumulation). Movement speed time-histories of deteriorated and non-deteriorated zones are generally consistent, both exhibiting a “double-peak” feature. Rockfall impact force first increases, stabilizes in the middle, and declines to stability afterward, with a maximum of 2.1 × 10⁹ N. The kinetic energy curve also shows a “double-peak” distribution, closely related to the on-site two-level steep cliff morphology. The findings provide important references for analyzing the dynamic evolution of such rockfalls and designing disaster prevention/mitigation engineering. Full article

In mountain areas, long linear transport infrastructures (roads, motorways, railways, etc.) are exposed to numerous natural hazards, especially hydrological and gravity-driven events such as slope instabilities, rockfalls, or torrential hazards. These phenomena can damage infrastructure, or even lead to the destruction of large sections, causing a risk for users and a deterioration of service. Infrastructure managers face several difficulties in handling these risks. One of them is identifying and representing them, due to the scale of the infrastructure, which is composed of numerous structures and exposed to multiple hazards. In this context, a model is proposed to represent all potential failure scenarios for such infrastructures. This model is based on system reliability analysis methods: functional analysis, failure mode and effect analysis (FMEA), and fault tree analysis (FTA). It is intended to be applied to a linear infrastructure, several kilometres long, exposed to various hazards. The proposed approach allows for the identification of all possible failure modes, including damage to structures and its functional consequences. Its applicability is being tested on a simple case study. Full article

In this work, the authors introduce an entirely solar-powered LoRa-based WSN consisting of several nodes, two stoplights, and four cameras. The system has been used to monitor the semi-rural area of Panni (FG), Puglia, Italy. The WSN has a totally custom implementation in both the node-gateway side and the gateway-user interface side. In particular, the communication framework is entirely IoT-based, featuring both the MQTT protocol, for the direct control of apparatuses from the system user interface, and the more traditional TCP/IP protocol, implemented on NB-IoT. The proposed system is entirely solar-powered and features a 34.68 mWh/day consumption. Around a single communication session, the average power consumption inside the single node amounts to 1.4 mW. This paper gives an overview of the proposed system, with detailed explanations of each part, and measurements retrieved over a wide period to assess the functionality of the system. Full article

Changes in land use and land cover (LULC) are crucial indicators to consider when examining various environmental challenges and assessing the sustainability of rapidly transforming landscapes. Land utilization in arid regions results from a diverse range of socioeconomic activities that reshape urban and regional environments. Using remote sensing and geographic information systems (GISs), the authors investigate the evolving and sustainability-sensitive landscape of the Al-Kawamel area, southwest of Sohag City, Egypt. Three time series of Landsat imagery, from 1985, 2005, and 2025, were used to map major LULC categories and evaluate their transformations with respect to elevation and slope. Based on the data analysis, the results reveal substantial shifts over the 40-year period in this low desert zone. During this time, the built-up areas and the agricultural lands expanded from 8 to 64 km² and from 10 to 131 km², respectively. Conversely, the desert zone declined from 325 to 148 km². These essential changes reflect intensified human activities and land reclamation. These rapid shifts increase exposure to natural and man-made hazards, including karstification, sand accumulations, rockfalls, flash floods, problematic soils, heavy metal hazards from wastewater disposal sites, and abandoned pits. Accordingly, suitable remediation methods should be assigned to minimize their impact. Full article

Rockfall hazard assessment and mitigation design relies heavily on three-dimensional trajectory modeling, in which the coefficient of restitution (COR) is a governing parameter controlling rebound, energy dissipation, and runout distance. In practice, COR values are commonly selected from generalized tables based on slope material type, introducing significant epistemic uncertainty and limiting predictive accuracy. This study presents a comparative evaluation of large-scale field rockfall experiments and 3-D numerical simulations conducted at a former aggregate quarry in Boise, Idaho, to assess the performance of tabulated restitution coefficients. Concrete blocks of controlled shape (spheres, cubes, and rectangular prisms) and mass (17–68 kg) were instrumented with inertial sensors and released from two slope configurations. High-resolution UAV-based LiDAR was used to reconstruct slope geometry, while dynamic cone penetrometer and friction tests were performed to characterize spatial variability in slope material stiffness. These data were incorporated into RocFall3 to simulate block trajectories using spatially varying COR values. Initial models assuming zero rotational velocity and tabulated COR ranges failed to reproduce observed runout distances, dispersion patterns, and modes of motion, particularly for non-spherical blocks. Incorporating field-measured initial rotational velocities significantly improved agreement between modeled and observed trajectories, by correcting the unrealistic sliding mode of motion previously observed. However, quantitative discrepancies in deposition and dispersion persisted, highlighting limitations associated with simplified slope geometry and the loss of small-scale surface features during LiDAR surface reconstruction. The results demonstrate that restitution behavior is strongly shape-dependent and that realistic initial conditions are essential for physically meaningful simulations. The findings underscore the need for site-specific, material-informed approaches to COR estimation and for improved integration of high-fidelity field data into physics-based rockfall models. Full article

The increase in population and demand for the various needs of citizens increases the interaction with the geo-environment. Thus, the rate of natural events affecting daily human life increases. Such an event occurred on a rock cliff in a densely populated area in İstanbul (Türkiye). More than four rock blocks (approximately 3–5 m³) belonging to the Paleozoic sequence of İstanbul, composed of nodular limestone with sandy-clay interlayers, detached and fell. The blocks traveled along a path of approximately 60 m and stopped by crushing a couple of buildings downslope. The path was rough and contained various surface conditions (e.g., bedrock, talus, and plants). This study was initiated by the examination of the dimensions of failed rock blocks, their paths, and topographic conditions. Unmanned vehicles (drones) facilitated the generation of 3D numerical models of topographic changes on the site. Quantifying discontinuity properties (such as persistence, spacing, roughness, etc.) and defining weathering properties comprises the second stage, along with sampling. Based on digital topographic data and field observations, cross-sections were defined by means of possible rockfall areas within the area of potentially unstable blocks. Numerical analysis and rockfall analysis were conducted along these critical sections. Interpretation of laboratory data and results obtained from numerical studies leads to an understanding of the mechanism of the recent rockfall event and demonstrates the most critical areas to be considered and reinforced. The research comprises proposing appropriate reinforcement techniques due to the strong Turkish regulations along the “Bosphorus Waterfront Protected Zone”. The study advises pre-cleaning of potentially unstable blocks after a fence production on paths where rocks could fall, and rock anchors in some localities with varying lengths. The latest part of the research covers the re-assessment of mitigation processes with numerical models, which shows that the factor of safety increased to the desired levels. The reinforcement applications at the site match well with the proposed prevention methods. Full article

Frequent geological hazards such as landslides and rockfalls, intensified by human activities and extreme rainfall, highlight the urgent need for rapid, accurate, and interpretable susceptibility assessment. However, existing methods often struggle with insufficient characterization of spatial heterogeneity, fragmented spatial structures, and limited mechanistic interpretability. To overcome these challenges, this study proposes an intelligent landslide susceptibility assessment framework based on the Swin-UNet architecture, which combines the window-based self-attention mechanism of the Swin Transformer with the encoder–decoder structure of U-Net. Eleven conditioning factors derived from remote sensing data were used to characterize the influencing conditions. Comprehensive experiments conducted in Changbai County, Jilin Province, China, demonstrate that the proposed Swin-UNet framework outperforms traditional models, including the information value method and the standard U-Net. It achieves a maximum overall accuracy of 99.87% and consistently yields higher AUROC, AUPRC, F1-score, and IoU metrics. The generated susceptibility maps exhibit enhanced spatial continuity, improved geomorphological coherence, and greater interpretability of contributing factors. These results confirm the robustness and generalizability of the proposed framework and highlight its potential as a powerful and interpretable tool for large-scale geological hazard assessment, providing a solid technical foundation for refined disaster prevention and mitigation strategies. Full article

The primary strata of western Taiwan are Cenozoic sedimentary rocks. Characterized by low cementation and high porosity, these rocks exhibit a pronounced wetting–softening effect. Long-term exposure to warm, humid tropical and subtropical climates significantly degrades their engineering geological properties due to weathering. This study, based on a sandstone-shale interbedded highway slope in central Taiwan that has repeatedly collapsed, investigated the slope’s failure mechanism using remote-sensing image interpretation of previous landslides, surface geological surveys, kinematic analysis, photogrammetric mapping, laboratory artificial weathering experiments, and Distinct Element Method (DEM) simulations. The study revealed that the fundamental cause of collapse on this type of oblique-slope interbedded sandstone-shale is the sliding and toppling of sandstone blocks, driven by weathering and erosion of the shale. Based on artificial weathering experiments, the strength loss rate of the shale in the Kuantaoshan Sandstone Member of the Kueichulin Formation after weathering is 6.6 times that of the sandstone. The estimated collapse area from the two-dimensional Distinct Element Method analysis is consistent with the actual value from the photogrammetric model. This type of landslide caused by rock weathering always forms stepped surface where sandstone overhangs above shale. A shale erosion amount of 0.78–0.91 of the spacing of the joint approximately parallel to the slope surface was found to be the critical erosion before collapse and can serve as the early warning indicator. Full article

This work presents the development and evaluation of a low-cost and low-power IoT system for monitoring slope instabilities, rockfalls, and landslides using LoRa communication. The prototype integrates commercial ESP32-based hardware with an SX1276 transceiver, a triaxial MEMS accelerometer, and a GPS module for real-time tilt and location measurements. A tilt-estimation expression was derived from accelerometer data, enabling adaptation to different terrain inclinations. Laboratory tests were performed to validate the stability and accuracy of the inclination measurement, followed by outdoor LoRa range tests under mixed line-of-sight conditions. A lightweight dashboard was implemented for real-time visualization of GPS position, signal quality, and tilt data. The results show reliable tilt detection, consistent long-range communication, and low power consumption, highlighting the potential of the proposed prototype as a scalable and energy-efficient tool for geotechnical monitoring. Full article

With the growing emphasis on bio-engineering techniques, the sustainable advantages of using trees as barriers against rockfalls have become increasingly evident. The key mechanism for forest protection against rockfalls is the dissipation of block kinetic energy during impacts. However, previous studies have primarily focused on the overall attributes of protection forests, with limited attention to the quantitative relationship between internal spatial structural parameters and protective effectiveness. This study systematically investigated the effects of tree diameter, plant spacing, and arrangement pattern on rockfall energy dissipation through physical experiments. The results indicate that: (1) The energy dissipation capacity of trees increases with tree diameter; however, the rate of increase declines significantly when the relative diameter (the ratio of tree diameter to block size) exceeds 0.4. (2) Rockfall energy dissipation increases with reduced plant spacing, but the resultant gain exhibits a diminishing trend. (3) Under otherwise identical conditions, the rhombus arrangement pattern achieved a significantly higher rockfall energy dissipation rate (82.67%) than the square pattern (49.28%). Based on the experimental findings, an optimized protection scheme was designed for a typical rockfall on the slope of the Lehong Tunnel in Yunnan Province, southwestern China. Three-dimensional numerical simulation validated the designed scheme. The designed protection forests dissipated 89.49% of the kinetic energy from 0.5 m blocks, demonstrating the practical efficacy of the parameters derived from experiments. This study quantifies the influence of internal spatial structure parameters on the protective effectiveness of forests against rockfalls, providing a valuable theoretical basis and practical guidance for the design of ecological prevention measures against rockfall hazards. Full article

Rockfall typically involves repeated impacts that induce progressive damage and fragmentation in rock masses. To investigate the mechanism governing this process under different impact velocities, a series of controlled impact tests were conducted using a newly developed compressed gas-driven rock impact apparatus. This study systematically examined the effect of impact velocities and number on rock damage, distinguishing between internal damage (<10.0 m/s) and local failure (10.0 m/s–20.0 m/s). At the internal damage level, uniaxial compression tests with acoustic emission monitoring were employed to analyze the macro-mechanical properties and micro-failure processes of granite. At the local failure level, the repeated impact number required to transition from localized to complete failure was recorded, and polarizing microscopy was used to characterize microstructural evolution. The results show that damage and failure mechanisms are strongly influenced by both impact velocity and repeated impact number. Specifically, higher impact velocities and repeated impacts promote a shift toward brittle failure, with threshold behaviors observed at 5.0 m/s (fourth impact) and 7.5 m/s (third impact). A quantitative analysis further correlates impact conditions with mechanical degradation and energy evolution, providing insight into the underlying processes controlling rockfall fragmentation. Full article

In response to the issue of local damage to mountainous bridges easily caused by rockfall impacts, carbon fiber cloth and steel plate strengthening methods were adopted to deeply study the impact of the width of carbon fiber cloth and steel plates on the strengthening effect. This study investigates the strengthening effectiveness of Carbon Fiber-Reinforced Polymer (CFRP) wraps and steel jackets on circular bridge piers, utilizing the ABAQUS finite element method. The analysis focuses on the effects of varying load conditions and confinement widths ranging from 100 to 200 cm, with a specific case study of a bridge pier in Nanchuan District, Chongqing. The research results show that the width of carbon fiber cloth and steel plates has a significant impact on the bridge pier’s impact resistance and damage resistance. There exists an optimal strengthening width that maximizes the strengthening effect. The stress distribution and displacement changes under different load conditions are affected by the width of the steel plate; the wider the steel plate, the better the strengthening effect, but the effect is not strictly linear. A comprehensive analysis method integrating multi-directional stress and displacement data was developed, incorporating weighting factors based on structural safety relevance. For both strengthening methods, a set of fitted formulas for widths between 100 cm and 200 cm was derived. This study provides systematic insights and practical guidance for the design of impact-resistant strengthening systems for bridge piers. Full article

The occurrence of mountainous geological hazards, primarily including rockfalls, landslides, and debris flows, is frequently influenced by multiple environmental factors and exhibits significant spatial heterogeneity and cumulative effects. To address the need for regional-scale susceptibility assessments within complex geological settings, we propose a novel geological hazard susceptibility assessment model based on conditional probability. This study establishes a dual-module evaluation framework incorporating certainty factors (CFs) and weights (W), in which the CF quantifies the contribution of each factor class to hazard occurrence, while the weights reflect the relative importance of the conditioning factors, thereby improving the model’s capability to characterize multifactorial coupling effects. Using three representative mountainous regions in Xinjiang, China—the Ili Valley Region (IVR), the Northern Piedmont of the Tianshan Mountains (NPTM), and the Kunlun–Altun Mountain Region (KAMR)—we integrate 7938 historical hazard points and 11 conditioning factors within a GIS environment to conduct the assessment. The results reveal regional differences in the weights of conditioning factors: IVR is primarily controlled by Elevation (0.184), Urban-Critical Infrastructure Density (0.163), and Annual Precipitation (0.156); NPTM is dominated by Annual Precipitation (0.153), Urban-Critical Infrastructure Density (0.145), and Road Density (0.136); and KAMR is governed by Elevation (0.197), Seismic Acceleration (0.167), and Hydrogeological Type (0.134). In IVR, NPTM, and KAMR, the Very-High and High susceptibility zones occupy 37.10%, 34.86%, and 26.23% of the land area, respectively, and contain 78.18%, 77.24%, and 82.10% of the identified geological hazards. The region-specific ROC-AUCs are 0.8536 (IVR), 0.8545 (NPTM), and 0.8775 (KAMR), indicating good predictive capability across sedimentary basins and tectonically active zones. This study provides methodological and data support for quantitative risk assessment of geological hazards at the regional scale under complex geological conditions. Full article