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Landslides cause severe damage to life and property with a wide-ranging impact. Infiltration of rainfall is one of the significant factors leading to landslides. This paper reports on a phase creep landslide caused by long-term rainfall infiltration. A detailed geological survey of the landslide was conducted, and the deformation development pattern and mechanism of the landslide were analyzed in conjunction with climatic characteristics. Furthermore, reinforcement measures specific to the landslide area were proposed. To monitor the stability of the reinforced slope, a Beidou intelligent monitoring and warning system suitable for remote mountainous areas was developed. The system utilizes LoRa Internet of Things (IoT) technology to connect various monitoring components, integrating surface displacement, deep deformation, structural internal forces, and rainfall monitoring devices into a local IoT network. A data processing unit was established on site to achieve preliminary processing and automatic handling of monitoring data. The monitoring results indicate that the reinforced slope has generally stabilized, and the improved intelligent monitoring system has been able to continuously and accurately reflect the real-time working conditions of the slope. Over the two-year monitoring period, 13 early warnings were issued, with more than 90% of the warnings accurately corresponding to actual conditions, significantly improving the accuracy of early warnings. The research findings provide valuable experience and reference for the monitoring and warning of high slopes in mountainous areas. [ABSTRACT FROM AUTHOR]

With the large-scale exploitation of mineral resources, the safety problems of open-pit slopes and dumps become increasingly prominent. In this work, the safety demonstration of the interaction between the eastside slope of an open-pit quarry and the dump was carried out. Firstly, the influence of blasting vibration on the stability of the eastside slope and the dump was analyzed, and the propagation law of blasting vibration wave and the attenuation law of velocity were obtained. Secondly, the finite element analysis of the seepage field of the slope was carried out, and the basic seepage parameters of the rock and soil were determined. Then, the limit equilibrium analysis method was used to quantitatively calculate the stability of the eastside slope of the stope under the load of the dump to assess landslide risk. The results show that no landslides would occur at the dump or affect the performance of the slope, and that the slope was able to reach the required safety reserve factor. Then, through the finite element analysis of the 3-3 profile, it was found that the deformation caused by the excavation unloading of the eastside slope was mainly concentrated in the lower part of the slope, and the displacement variation caused by the top area of the slope was about 0~10 mm. The research verified the stability of slope and dump, which provides technical support for slope project design and blast operation in open-pit quarries. [ABSTRACT FROM AUTHOR]

Deep-Seated Gravitational Slope Deformations (DSGSDs) are common in many geological environments, and due to their common limited displacement rate, they can remain unrecognized for a long time. Among the most significant events in Sicily is the Mt. San Calogero DSGSD. To contribute to a better understanding of its characteristics, including the geologic setting promoting its development, ongoing kinematics, and mechanism, a specific analysis was completed. In this paper, the results of this analysis, based on a three-folded strategy, are provided and interpreted in the context of DSGSD predisposing conditions and controlling factors. Especially, field observations associated to visual interpretation of aerial imagery were used for the identification and mapping of main geological features and landforms, high-resolution X-Band DInSAR data enabled researchers to fully characterize the deformational behavior of the slope, while a reduced complexity slope stability analysis allowed them to reconstruct the deep geometry of the DSGSD. Results from the analysis indicate that the DSGSD of Mt. San Calogero is composed of three blocks corresponding to fault-bounded tectonic elements and characterized by a specific kinematics and sensitivity to external forcing (i.e., rainfall), multiple landslides are associated to the DSGSD in the area and the deep geometry of the DSGSD is concave upward and resemble the characteristics of a rotational slide. The interpretation of the results suggests that the formation and the deformation of the Mt. San Calogero DSGSD are linked with the local and regional fault systems related to the Sicilian orogen, while shallow landslides are triggered, in clayey terrains, mostly by rainfalls. In addition, the integrated approach reveals that active tectonics and rainfalls in the San Calogero massive relief are the main driving forces of its different deformation behavior. [ABSTRACT FROM AUTHOR]

Landslides in colluvial soils under rainfall have been identified as a significant problem due to their loose, heterogeneous nature and low shear strength. Evaluation of the stability of colluvial slopes under rainfall conditions is challenging. This study investigated two landslide failure case studies of colluvial soils to understand the failure patterns using finite element (FE) and limit equilibrium (LE) slope stability analysis methods under unsaturated conditions. Transient seepage conditions due to rainfall infiltration and failure were analysed using hydromechanical models. Here, a FE fully coupled hydromechanical model and a sequential coupling of a FE hydrological and LE mechanical model were used to evaluate the failure of variably saturated slopes. Results from the case studies revealed that the failure occurred due to the rise in the groundwater table in both cases. It was evident that there can be significant disparities in the pore water pressure profiles with the fully coupled and sequentially coupled analysis. The dynamic capability of the two models can also affect the interplay between the hydrological and mechanical aspects. When the thickness of the colluvium layer is large, the failure could potentially occur as a deep-seated failure along the boundary of overburden and the bedrock surface due to the large driving force. However, when the thickness is small, failure can occur along the colluvium-weathered rock surface. The outcomes from the study will contribute to mitigate the uncertainty of failure prediction of landslides in colluvial soils. [ABSTRACT FROM AUTHOR]

A massive landslide occurred in Domeshi area, District Muzaffarabad, Pakistan, in two distinct phases: an initial movement on August 1, followed by complete failure on August 4, 2023. The landslide movement persisted for 96 h, with a runout distance of 500 m. The event destroyed numerous residential structures, impacting multiple families, and causing extensive damage to cultivated land and road infrastructure. To comprehensively understand the failure mechanisms, a detailed study was undertaken, encompassing site investigations, unmanned aerial vehicle (UAV) photography, geotechnical and geophysical investigations, petrographic analysis, kinematics, and numerical simulations. The field evidence indicates that the active deformation along the Jhelum Fault (JF) within the landslide's main body weakened the surrounding rock formations. Intense rainfall saturated pre-existing fractures, creating critical zones of weakness. Highly plastic clays along fault plane contributed significantly to volume changes, especially during and after rainfall events. Kinematic analysis identified bedding joints as prevalent failure planes for planar sliding. Geophysical survey revealed a layer of unconsolidated material extending 25–30 m below the landslide's scarp, accompanied by various fractures, including a deep fracture (i.e., JF) up to 300 m depth. Petrographic investigations showed microfractures, micro faults, and intragranular mineral breakage, indicative of intense tectonic stresses. Slope stability analysis indicated factors of safety (FoS) and strength reduction factor (SRF) less than 1, suggesting the potential for further failure in the lower sections of the landslide. Multiple factors, including slope geometry, active tectonics, material composition, and anthropogenic factors (i.e., slope loading and cutting for road and building construction, improper drainage distribution), contributed to the landslide's occurrence, however, the rainfall emerged as the primary triggering event. [ABSTRACT FROM AUTHOR]

This paper presents the implementation of a slope stability method for rainfall-induced shallow landslides in CRITERIA-1D, which is an agro-hydrological model based on Richards' equation for transient infiltration and redistribution processes. CRITERIA-1D can simulate the presence and development of roots and canopies over space and time, the regulation of transpiration activity based on real meteorological data, and the evaporation reduction caused by canopies. The slope can be considered composed of a multi-layered soil, leading to the possibility of simulating the bedrock and of setting an initial water table level. CRITERIA-1D can consider different soil horizons characterized by different hydraulic conductivities and soil water retention curves, thus allowing the simulation of capillarity barriers. The validation of the proposed physically based slope stability model was conducted through the simulation of the collected water content and water potential data of an experimental slope. The monitored slope is located close to Montuè, in the north-eastern sector of Oltrepò Pavese (northern Apennines—Italy). Just close to the monitoring station, a shallow landslide occurred in 2014 at a depth of around 100 cm. The results show the utility of agro-hydrological modeling schemes in modeling the antecedent soil moisture condition and in reducing the overestimation of landslides events detection, which is an issue for early warning systems and slope management related to rainfall-induced shallow landslides. The presented model can be used also to test different bioengineering solutions for slope stabilization, especially when data about rooting systems and plant physiology are known. [ABSTRACT FROM AUTHOR]

Landslides resulting in complete river blockage have frequently occurred in the Three River Region (TRR) during the geomorphological evolution of the Tibetan Plateau. River-damming landslides occurring in low-relief regions of the TRR have received less attention compared to those in deeply-incised valleys. The 2.5 Mm3 Cuoduoqin rockslide originated from the south-facing hillslope of a southeast-east-trending ridge, leading to complete blockage of the Quzhaqu River. The original failure mainly involves blocky metamorphic limestone and phyllite. The Quzha Lake Fault providing rear rupture and two other groups of joints facilitating sidewise and toe releases are considered predisposing factors contributing to slope instability. Ongoing tectonic uplift and cyclic glaciations are considered preparatory factors, shifting the slope from stable to marginally unstable. A prehistoric earthquake, likely corresponding to an ancient rupture event on the active Nujiang Fault Zone (NJFZ), is deemed as the most probable trigger for this large rock slope failure. The 2D discrete element method (DEM) software UDEC is utilized to analyze the static slope stability and to reproduce the kinematic process of the rockslide. The static analysis indicates that the original rock slope was in equilibrium under natural conditions. The kinematic process can be divided into three phases: initial detachment within seconds after applying seismic load, downslope acceleration after crossing the slope knickpoint, and accumulation after traveling into the valley bottom. This case study, focusing on the development and kinematics of the Cuoduoqin rockslide, can help enhance the understanding of effective risk assessments of landslides in high-altitude and low-relief regions. [ABSTRACT FROM AUTHOR]

Bioinspired slope improvements can achieve outcomes similar to traditional slope improvements for shallow slope failures, while incorporating plant material as a structural component and using a minimum of heavy equipment. Vetiver grass can mitigate the rain-induced slope instability of earthen infrastructure, such as levees, constructed using loess and clay soils. Vetiver grassroots can extend to depths greater than 3 m (10 ft), creating a new composite material with the grassroots and soil, thereby increasing shear strength to combat shallow slope failures. The objective of this study is to determine the feasibility of vetiver as a climate-resilient bioinspired slope stability improvement on a test levee constructed of loess in Vicksburg, Mississippi (MS). Vetiver was planted at 1 ft center-to-center intervals on a 9.1 m wide (30 ft) section of an approximately 12.2 m long (40 ft) downstream slope of a test levee and observed for 2.5 years. To consider the effect of extreme precipitation events, a finite element analysis was completed for a comparable clay slope using 500 year precipitation intensity–duration–frequency curves of Jackson, MS. Precipitation negatively impacts the collapsible and expansive nature of the local loess and clay, respectively. The results demonstrate that vetiver grass is a viable method to increase slope stability for earthen levees constructed with loess and clay, which are prevalent in Vicksburg and Jackson, respectively. Vetiver also holds promise as a climate resilient solution to combat rain-induced shallow slope failures. Practical Applications: As society advances toward a more sustainable approach to managing infrastructure, traditional methods of using heavy machinery, concrete, and steel to repair landslides are being replaced with using minimal equipment, earthen and geosynthetic materials, and vegetation. Earthen infrastructure, such as dams and levees, provide protection against the flooding of basins, rivers, lakes, and other bodies of water; however, they are not immune from landslides. One common landslide that can occur in earthen infrastructure is a shallow slope failure, particularly in soil that destabilizes greatly with changes in climate, such as collapsible and expansive soils. The researcher is proposing to use vetiver grass to combat shallow slope failures in earthen infrastructure in MS. Vetiver grassroots can grow to depths greater than 3 m (10 ft), which exceeds the depths of shallow landslides. Vetiver was transplanted on a test levee that was no longer being used in Vicksburg to determine if vetiver could grow in loess. Further, computer modeling was done to predict the performance of vetiver on a levee constructed in clay following storms with an estimated return period of 500 years for Jackson. The use of vetiver was determined to reduce the possibility of shallow slope failures under the conditions specified. [ABSTRACT FROM AUTHOR]

Cyclic water level fluctuations have been suspected to be the main cause of many reservoir-induced landslides. Rim slope failures are a constant hurdle in the smooth functioning of the hydro-power projects. Understanding of mechanism involved in reservoir-induced landslides, and the assessment of landslide displacement due to water fluctuation is very complex. There is a need for a quick assessment tool for landslide displacement to ensure safe operation of hydro-power plants. In the present article, effect of cyclic fluctuation in reservoir water level on the stability of rim slope has been studied through physical modeling. A small-scale physical slope model test (PSMT) apparatus was developed indigenously and results of tests conducted on 45° modelled soil slope have been discussed. The modelled slope was made using soil samples collected from an actual rim slope situated between Tehri and Koteshwar Dam (India) and was subjected to 30 cycles of water level fluctuations. Total head values and deformations were recorded after every cycle drawdown. Based on the experimental results, a hypothesis on initiation and propagation of reservoir-induced landslides is suggested. A dimensionless term called Spread Index (Si) is defined as the ratio of Spread (horizontal displacement at toe) and Hydro-Fluctuation Belt of the cyclic fluctuation in the reservoir water level. A novel simple approach is proposed based on the spread index to predict displacement of soil rim slopes subjected to cyclic fluctuations as an extended application of the present study. The proposed solution will be helpful for rough estimation of displacements along rim slopes. [ABSTRACT FROM AUTHOR]

Mining causes damage to the soil and rock mass, while rainfall has a pivotal impact on the mining slope stability, even leading to geological hazards such as landslides. Therefore, the study evaluated the mine landslide stability and determined the effectiveness of the treatment measures under the impact of pore water pressure changes caused by rainfall, taking the Kong Mountain landslide in Nanjing, Jiangsu Province, China, as the research object. The geological conditions and deformation characteristics were clarified, and the failure mechanism and influencing factors were analyzed. Also, the landslide stability was comprehensively evaluated and calculated utilizing the finite element-improved limit equilibrium method and FLAC 3D 6.0, which simulated the distribution of pore water pressure, displacement, etc., to analyze the influence of rainfall conditions and reinforcement effects. The results indicated the following: (1) Rainfall is the key influencing factor of the landslide stability, which caused the pore water pressure changes and the loosening of the soil due to the strong permeability; (2) The distribution of the pore water pressure and plastic zone showed that, during the rainfall process, a large area of transient saturation zone appeared at the leading edge, affecting the stability of the whole landslide and led to the further deformation; (3) After the application of treatment measures (anti-sliding piles and anchor cables), the landslide stability increased under both natural and rainfall conditions (from 1.02 and 0.94 to 1.38 and 1.31, respectively), along with a reduction in displacement, plastic zones, etc. The Kong Mountain landslide, with the implemented treatment measures, is in good stability, which is in line with the evaluation and calculation results. The study provides certain contributions to the stability evaluation and treatment selection of similar engineering under rainfall infiltration. [ABSTRACT FROM AUTHOR]

Landslides are the main gravitational phenomena in the Neogene basins of Algeria. This feature is mainly favored by the lithological nature of the fill materials, the climate, and the slope morphology. They are known for their high residential concentration and urban development. For better management and planning of future projects in landslide-prone areas, the use of Landslide Susceptibility Maps (LSMs) is indispensable. This study proposes a combined statistical and limit equilibrium method for the analysis of slope stability and for the production of LSMs using GIS in the Aomar Neogene basin (Bouira, Algeria). For this purpose, different work steps were carried out. Initially, a landslide inventory map was prepared based on existing studies, high-resolution aerial photography and satellite imagery analysis, as well as on detailed fieldwork. Besides, the geotechnical characterization of each geological formation was determined from the physical and mechanical parameters of recent and old geotechnical studies conducted in the region. A total, 169 landslides were compiled and randomly divided into training (70%) and validation (30%) datasets. Furthermore, eight factors influencing landslide occurrence (including slope angle, lithology, slope aspect, elevation, drainage density, distance to the rivers, distance to the roads, and rainfall) were selected and applied for the analysis. Moreover, the inventoried landslide and their associated factors were taken into account when mapping landslide susceptibility in the Aomar Neogene basin using Frequency Ratio (FR) models in GIS. On the other hand, a two-dimensional limit equilibrium (LE) model was used to determine the landslide-prone zones with a distinctive stability factor for each slope and the failure surface depth. Then, we have been able to verify and validate the obtained results for the statistical method using the Area Under the Curve (AUC) value of the Receiver Operating Characteristics Curves (ROC) method. For the frequency ratio models, the AUC is 83.23%, and for the limit equilibrium method, the safety factor is less than one for a slope greater than 16°. Based on these findings, we draw the conclusion that the maps may be exploited as practical instruments for land use planning and risk reduction in the Aomar Neogene basin. [ABSTRACT FROM AUTHOR]

The Green–Ampt (GA) model is a widely used analytical method to calculate the depth of the wetting front during intense rainfall. However, it neglects the existence of the transition layer and the seepage parallel to the slope surface. Therefore, a modified stratified Green–Ampt (MSGA) model is proposed. A process to assess the stability of the finite slope during a rainfall event is demonstrated by combining the MSGA model and the limit equilibrium method. In the case of the Liangshuijing landslide, the factor of safety presents a negative correlation with the depth of the wetting front. The factor of safety obtained by the stratified Green–Ampt (SGA) model is smaller than that calculated by the MSGA model, and the gap between the factor of safety based on the two methods widens with time. The moving speed of the wetting front accelerates with the increase in the length of the slope surface, and the size effect becomes apparent when the length is short. In the initial stage of infiltration, the effect of the seepage parallel to the slope surface is small. The effect of the seepage cannot be neglected at the latter stage. The result calculated by the MSGA model agrees well with the measured result in the test. [ABSTRACT FROM AUTHOR]

The persistent trend of rising temperatures and shifting weather patterns caused by climate change has prompted significant concern around the world. This research aims to evaluate the instability of slopes in Almaty, Kazakhstan, under various rainfall patterns, groundwater tables, and slope geometries by incorporating the principles of unsaturated soil mechanics. However, there have been a limited number of studies incorporating the principle of unsaturated soil mechanics with constant rainfall patterns in Central Asia, particularly in Kazakhstan, on the impact of rainfall-causing landslides. Hence, in this research, GeoStudio software (SEEP/W and SLOPE/W) was used to simulate the factor of safety (FoS) and pore water pressure for the investigated slopes under different rainfall patterns. Results from Hyprop and statistical method show that the saturated volumetric water content is 0.502, whereas the residual one is 0.147 and for the permeability function the conductivity coefficient started to sharply decrease at the suction value of 2 kPa when the air-entry value was 24 kPa. Findings from numerical analysis show the change in FoS for the slope of 10mheight and 27-degree slope angle was 6%, 7%, 7%, and 8% for cyclic, delayed, advanced, and normal distributions, respectively. For the slope with 20 m height and the same 27-degree angle, the change in FoS was 8%, 10%, 8%, and 11% for the cyclic, delayed, advanced, and normal distributions, respectively. These same patterns were shown in slopes with 35-degree and 45-degree angles, having the same 10 m and 20 m heights. Comparatively, this shows that slopes under cyclic rainfall patterns (240mmof rain within 12 days) are less prone to failure compared to slopes under continuous, delayed, or regularly distributed rainfall patterns. Moreover, an increase in slope height and angle also affect the FoS negatively. It should be noted that the results obtained are only applicable to clayey-loam soil. [ABSTRACT FROM AUTHOR]

Climate change often leads to increased precipitations and thus affects natural terrain stability, leading to landslides and infrastructure damage. Infrastructure failure causes economic losses, societal disruption, and hampers emergency response and recovery efforts. For example, a significant challenge to the stability of natural slopes is the intensification of heavy precipitation events due to climate change. Increased precipitation rates can intensify soil erosion and soil saturation, resulting in increased instability and a higher risk of slope failure. This work consolidates current insights derived from practical engineering based on detailed investigation as well as rigorous research on the interplay between climate change, land‐use changes, geomorphological characteristics, and their collective influence on slope stability, landslides, and infrastructure integrity. Two case studies from South America are presented to analyze such effect of climate change. Collaboration between civil engineering and climate disciplines, foremost meteorology along with predictive risk management, is essential for sustainable infrastructure in evolving climates. [ABSTRACT FROM AUTHOR]

Landslides pose significant threats to life and property, particularly in mountainous regions. To address this, this study develops a landslide susceptibility model integrating Earth Observation (EO) data, historical data, and Multi-Temporal Interferometric Synthetic Aperture Radar (MT-InSAR) ground movement results. The model categorizes areas into four susceptibility classes (from Class 1 to Class 4) using a multi-class classification approach. Results indicate that the Xtreme Gradient Boosting (XGB) model effectively predicts landslide susceptibility with area under the curve (AUC) values ranging from 0.93 to 0.97, with high accuracy of 0.89 and a balanced performance across different susceptibility classes. The integration of MT-InSAR data enhances the model's ability to capture dynamic ground movement and improves landslide mapping. The landslide susceptibility map generated by the XGB model indicates high susceptibility along the Pacific coast. The optimal model was validated against 272 historical landslide occurrences, with predictions distributed as follows: 68 occurrences (25%) in Class 1, 142 occurrences (52%) in Class 2, 58 occurrences (21.5%) in Class 3, and 4 occurrences (1.5%) in Class 4. This study highlights the importance of considering temporal changes in environmental conditions such as precipitation, distance to streams, and changes in vegetation for accurate landslide susceptibility assessment. [ABSTRACT FROM AUTHOR]

Assessing the risk of landslides as a result of intense seismic vibrations is an urgent problem in engineering geology. In this article, to assess slope stability, a method is proposed for normalizing the internal deformation of a slope, based on a probabilistic-stochastic approach. The cumulative Newmark displacement is considered as a normalized value, for which empirical relationships have been selected among the accumulated displacement, the level of seismic impact, and the critical acceleration specified by the material parameters of the slope. The method takes into account the uncertainties in the position of possible earthquake sources in the next 50 years in the vicinity of the studied slope, the magnitude of the event(s), and the level of seismic impact. The uncertainties in the physicomechanical parameters of the slope are also taken into account. Normative biases are estimated using reference exceedance probabilities (10 and 5%). The obtained values are compared with the threshold characteristics, and based on this, a decision is made on the slope stability to seismic loads. The value of 10 cm was taken as the lower threshold at which the slope can be considered stable. The technique was successfully tested on a well-studied area of the western slope of Mt. Bolshevik (the south of Sakhalin Island). The balanced estimate of the normative displacement for a 5% exceedance probability was slightly less than 10 cm. The study also provides recommendations for further improvement of the methodology. [ABSTRACT FROM AUTHOR]

An improved method for fast and reasonable estimation of seismically induced permanent displacement of bedding rock slopes is proposed in this study. The proposed method introduces the pseudo-dynamic seismic force to account for the amplification effect induced by the slope topography. In addition, real-time updates of the tangential-normal coupling forces on the sliding surface during seismic excitations are implemented. The feasibility and adaptability of the proposed method are verified through a comparison with existing methods. Additionally, the differences between the earthquake-induced displacements calculated using the proposed method and the Newmark method are analyzed using 171 strong ground motion records as input excitations. A parametric sensitivity analysis shows that permanent displacement is significantly influenced by the friction angle of the joint ϕ , amplitude of the input acceleration P 0 , dip angle of the slope failure plane β , and slope height H . Finally, a set of landslide probability maps is obtained, and a landslide probability estimation procedure for slopes is recommended, which provides a convenient way to preliminarily evaluate the seismic stability of bedding rock slopes. Highlights: The amplification effect on the seismic response of rock slopes is considered. Tangential-normal forces on the sliding surface were coupled. Automatic recognition of sliding status is based on the Mohr–Coulomb criterion. Landslide probability maps are provided. [ABSTRACT FROM AUTHOR]

The riverbank areas of the Arequipa region are periodically subject to landslides caused by seismic activity, natural changes in land structure, and climate-related factors. These events have significant social and economic impacts on the local population. Therefore, it is crucial to explore sustainable, efficient, and costeffective methods for stabilizing slopes. One such method involves enhancing slope stability by increasing the shear strength of the soil through unconventional means. This study examines how adding roots from two perennial crops affects the shear strength of silty sand soils near a riverbank in Arequipa City. The study specifically focuses on Distichlis spicata and Kikuyuochloa clandestine crops, which have extensive root systems developed through stolons. Physical characterization tests were carried out on two samples of silty sand along with direct shear tests using different values of root area ratio at various depths to assess soil-root interaction parameters comprehensively. The test results indicate that both Distichlis spicata crop and Kikuyuochloa clandestina crop alter the soil's shear strength by increasing the friction angle. The modification of cohesion depends on the specific type of crop as well as soil characteristics. Thus, both crops decrease cohesion in one type of soil and increase it in the other one. It can be concluded that integrating these crops into soils significantly enhances their maximum shear stress under elevated normal stresses, thus improving slope stability overall. [ABSTRACT FROM AUTHOR]

Monitoring natural slopes, embankments, and unstable slopes is crucial to reducing predisposition to mass movements, especially in areas with geotechnical instability and high rainfall. This study proposes a methodology to identify geotechnical and pluviometric triggers of mass movements in railway slopes. It involves registering slopes and embankments along the railroad, recording accumulated rainfall indices, and documenting associated accidents. The experimental program included a cadastral survey at a pilot site on the MRS company's railway network in the Paraopeba branch, Minas Gerais, Brazil. Surface and subsurface drainage conditions, anthropic interventions, and modifications affecting slope stability were also examined. Additionally, the history of accidents involving geotechnical and regional rainfall indices were incorporated to identify potential triggering events for mass movements. The study found a good correlation between landslide records and geotechnical risk mapping but a low correlation between landslide records and rainfall isohyets. The latter result is attributed to the low density and poor distribution of rainfall data and active pluviometers in the region. Overall, understanding the geological–geotechnical characteristics of slopes and the correlation between accidents and rainfall indices provides valuable insights for predicting potential landslide occurrences. [ABSTRACT FROM AUTHOR]

Land cover changes in mountainous areas due to silvo-pastoral abandonment can affect soil stability, especially on steep slopes. In addition, the increase in rainfall intensity in recent decades requires re-assessing landslide susceptibility and vegetation management for soil protection. This study was carried out using the software SlideforMAP in the Mt. Nerone massif (central Italy) to assess (i) the effects of land cover changes on slope stability over the past 70 years (1954–2021) and (ii) the role of actual vegetation cover during intense rainfall events. The study area has undergone a significant change in vegetation cover over the years, with a reduction in mainly pastures (−80%) and croplands (−22%) land cover classes in favor of broadleaf forests (+64%). We simulated twelve scenarios, combining land cover conditions and rainfall intensities, and analyzed the landslide failure probability results. Vegetation cover significantly increased the slope stability, up to three to four times compared to the unvegetated areas (29%, 68%, and 89%, respectively, in the no cover, 1954, and 2021 scenarios). The current land cover provided protection against landslide susceptibility, even during extreme rainfall events, for different return periods. The 30-year return period was a critical condition for a significant stability reduction. In addition, forest species provide different mitigation effects due to their root system features. The results showed that species with deep root systems, such as oaks, provide more effective slope stability than other species, such as pines. This study helps to quantify the mitigation effects of vegetation cover and suggests that physically based probabilistic models can be used at the regional scale to detect the areas prone to failure and the triggering of rainfall-induced shallow landslides. This approach can be important in land planning and management to mitigate risks in mountainous regions. [ABSTRACT FROM AUTHOR]

AbstractRainfall infiltration is a primary cause of slope failure. Analyzing the entire process of a landslide triggered by rainfall is crucial for the design of infrastructure. However, the complexity associated with simulating large deformations has often hindered previous studies from modeling the entire landslide process subsequent to rainfall infiltration. This study aims to provide a method to simulate the entire process of landslides considering rainfall and more insight into the mechanism of landslides. The discrete element method (DEM) is first applied to model the entire process of shallow landslides triggered by rainfall. The numerical results indicate that the intensity and duration of rainfall infiltration have significant impacts on the slope stability. The particle displacement field, resulting from landslides due to rainfall, corresponds with three distinct stages within the landslide process. The increased rainfall intensity causes the area of the particles within failure mass grows rapidly during the initial stage of the landslide. The closer to the slope surface the faster the particle velocity. The simulations demonstrate that the slope surface transitions from a linear to a concave downward geometry during the landslides. Larger particles display greater displacement and velocity compared to smaller particles. [ABSTRACT FROM AUTHOR]

Cascading landslides are specific multi-hazard events in which a primary movement triggers successive landslide processes. Areas with dynamic and quickly changing environments are more prone to this type of phenomena. Both the kind and the evolution velocity of a landslide depends on the materials involved. Indeed, rockfalls are generated when rocks fall from a very steep slope, while debris flow and/or mudslides are generated by fine materials like silt and clay after strong water imbibition. These events can amplify the damage caused by the initial trigger and propagate instability along a slope, often resulting in significant environmental and societal impacts. The Morino-Rendinara cascading landslide, situated in the Ernici Mountains along the border of the Abruzzo and Lazio regions (Italy), serves as a notable example of the complexities and devastating consequences associated with such events. In March 2021, a substantial debris flow event obstructed the Liri River, marking the latest step in a series of landslide events. Conventional techniques such as geomorphological observations and geological surveys may not provide exhaustive information to explain the landslide phenomena in progress. For this reason, UAV image acquisition, InSAR interferometry, and pixel offset analysis can be used to improve the knowledge of the mechanism and kinematics of landslide events. In this work, the interferometric data ranged from 3 January 2020 to 24 March 2023, while the pixel offset data covered the period from 2016 to 2022. The choice of such an extensive data window provided comprehensive insight into the investigated events, including the possibility of identifying other unrecorded events and aiding in the development of more effective mitigation strategies. Furthermore, to supplement the analysis, a specific finite element method for slope stability analysis was used to reconstruct the deep geometry of the system, emphasizing the effect of groundwater-level flow on slope stability. All of the findings indicate that major landslide activities were concentrated during the heavy rainfall season, with movements ranging from several centimeters per year. These results were consistent with numerical analyses, which showed that the potential slip surface became significantly more unstable when the water table was elevated. [ABSTRACT FROM AUTHOR]

Landslide is a disastrous geological hazard in the Three Gorges Reservoir (TGR) area of China. In this study, random limit equilibrium analysis is conducted to assess a layered slope stability influenced by multi-factors in spatially variable soils, where the effects of earthquake, reservoir water level drawdown and rainfall are investigated, and possible failure modes and failure paths are identified. Furthermore, some sensitive analysis is performed to investigate the effects of the spatial variability of soil properties, water level drawdown velocity, rainfall intensity and pattern. Results show that the layered slope under complex working conditions exhibits the shallow failure modes, and the sliding surfaces are mainly located at the interface between soil layers. Meanwhile, the shear strength parameters in the shallow depth plays a crucial role in the layered slope failure probability. The earthquake has a prominent effect on slope stability, followed by reservoir water level drawdown and rainfall infiltration. The probability of failure under the combined effects of earthquake and other factors (e.g., 23.5%, 31.4% and 44.6%) is significantly higher than under the combined effects of rainfall and water level drawdown (e.g., 15.9%). Moreover, it can be found that the spatial variability of soil properties, water level drawdown velocity, rainfall intensity and pattern have essential impacts on the slope failure probability. [ABSTRACT FROM AUTHOR]

The issue of rainfall-induced slope failure has attracted more attention from geotechnical engineers as a consequence of global warming. Current cumulative waste disposal has generated scientific interest in the utilization of waste materials in geotechnical design for climate change adaptation measures. Taking into consideration the effect of slope height and angle, steel slag—a waste product derived from the production of steel—was investigated as a slope cover against rainfall. To assess the stability of the slope and the infiltration of water into the soil, numerical analyses were conducted using both SEEP/W and SLOPE/W software in conjunction with rainfall conditions. Based on the findings, it can be concluded that increasing the slope's elevation and inclination will have an adverse effect on its safety factor. Steel slag can nevertheless be utilized for minimizing rainwater infiltration into the slope, as indicated by the pore-water pressure variations and graphs of the safety factor versus time. For a 20-m slope height, steel slag slopes have demonstrated a lower factor of safety difference in comparison to the initial slope without remediation. Regardless of slope angle and slope height, the safety factor reduces marginally during rainfall. [ABSTRACT FROM AUTHOR]

Quantitative calculation of single landslide risk has great significance for the prevention and treatment of landslides, through analysing the slope stability under different rainfall recurrence periods. In this study, the rainfall of the past 40 years in Xun'wu County of China is counted and the rainfall during the return periods of 10, 20 and 50 years are calculated to form three different rainfall conditions. Then, the stability of Cheng'nan landslide in Xun'wu County is calculated by the Geo‐Studio 2007 software, and the probability of landslide occurrence is obtained by Monte Carlo theory under these three conditions. Next, the field investigation is employed to obtain the statistical results of the buildings and personnel in the affected area of Cheng'nan landslide. Finally, the risk of economic loss and casualty under the three conditions are calculated. It was demonstrated that: (1) Under the three conditions, the safety factor decreased gradually, the rate of decrease was slower in the first 3 days and faster in the middle period and there was still a downward trend after the end of the rain. (2) The probability of landslide occurrence during the rainfall return periods of 10, 20 and 50 years were 1.77%, 2.97% and 1.61%, respectively. Besides, the risk index of landslide was the highest under the condition of 20‐years rainfall return period. (3) The economic loss risk and casualty risk in the rainfall return periods of 10, 20 and 50 years were 122,700‐yuan and 4.11 people, 205,900‐yuan and 6.89 people, as well as 11,600‐yuan and 3.74 people, respectively. [ABSTRACT FROM AUTHOR]

The occurrence of landslide hazards significantly induces changes in slope surface displacement. This study conducts an in-depth analysis of the multifractal characteristics and displacement prediction of highway slope surface displacement sequences. Utilizing automated monitoring devices, data are collected to analyze the deformation patterns of the slope surface layer. Specifically, the multifractal detrended fluctuation analysis (MF-DFA) method is employed to examine the multifractal features of the monitoring data for slope surface displacement. Additionally, the Mann–Kendall (M-K) method is combined to construct the α indicator and f (α) indicator criteria, which provide early warnings for slope stability. Furthermore, the long short-term memory (LSTM) model is optimized using the particle swarm optimization (PSO) algorithm to enhance the prediction of slope surface displacement. The results indicate that the slope displacement monitoring data exhibit a distinct fractal sequence characterized by h (q) , with values decreasing as the fluctuation function q decreases. Through this study, the slope landslide warning classification has been determined to be Level III. Moreover, the PSO-LSTM model demonstrates superior prediction accuracy and stability in slope displacement forecasting, achieving a root mean square error (RMSE) of 0.72 and a coefficient of determination (R2) of 91%. Finally, a joint response synthesis of the slope landslide warning levels and slope displacement predictions resulted in conclusions. Subsequent surface displacements of the slope are likely to stabilize, indicating the need for routine monitoring and inspection of the site. [ABSTRACT FROM AUTHOR]

Landslides in Alpine valleys pose significant hazards due to potential impacts on inhabited areas and landslide-dam formation. These valleys feature diverse glacial deposits (moraine, debris talus, and glacio-fluvio-lacustrine materials) with varying technical traits. A comprehensive study investigated a Carnic Alps landslide in northeastern Italy, focusing on moraine deposits. This entailed geological-geomorphological analyses, slope deformation monitoring, and utilisation of 2D and 3D stability models. The 19th-century landslide occurred in Tolmezzo, Friuli Venezia Giulia, and affected the Cazzaso village. Geological-geomorphological studies involved LiDAR-derived terrain models, borehole-based slope stratigraphy, and inclinometer-derived landslide characterisation. Deformation data combined GPS measurements and multi-temporal interferometric synthetic aperture radar. Reconstructing the slope's geological model, stability assessments employed 2D and 3D limit equilibrium methods, factoring in groundwater and seismicity. Validation occurred against monitoring data and geologicalgeomorphological observations. The 3D models further identified most landslidesusceptible zones. [ABSTRACT FROM AUTHOR]

The undrained shear strength of marine sediment is of vital importance because of its critical role in seafloor slope stability, seafloor infrastructure, and influencing sediment dynamics that can lead to underwater landslides. Therefore, understanding the undrained shear strength of marine sediments and its influencing factors is a fundamental requirement for both offshore engineering and geoscience studies. Core data obtained from 198 sites across 46 legs of the Ocean Drilling Program/International Ocean Discovery Program (ODP/IODP) were used to analyze the undrained shear strength of marine sediments and their influencing factors. The undrained shear strength of marine sediments is significantly influenced by the depositional environment. Sediments deposited in active continental margins exhibit a higher undrained shear strength than those deposited in deep-sea and carbonate platform environments due to seismic strengthening and over-consolidation. It was found that fine-grained siliciclastic lithofacies with less than 50% carbonate content exhibited high variability and a rapid increase in the undrained shear strength with depth. In contrast, fine-grained carbonate lithofacies with more than 50% carbonate, as well as reef-facies carbonates, showed low variability and only a gradual increase in undrained shear strength with depth. Additionally, we showed a positive association between the undrained shear strength and physical characteristics including bulk density and P-wave velocity, as well as an inverse correlation with porosity. An exponential relationship was found between these physical properties and the undrained shear strength, with coefficients of determination (R²) values of 0.71, 0.74, and 0.69, respectively. [ABSTRACT FROM AUTHOR]

This study presents a long-term reactivation monitoring approach using multi-source satellite SAR and optical data. It also explores the relationship between landslide deformations and hydrological factors for reactivation assessment and management. More specifically, this approach is applied to investigate the long-term reactivation evolution of the Huangtupo landslide under the local engineering work conducted in four different phases. The spatial–temporal evolutions of the Huangtupo landslide were mapped by the multi-temporal optical images from the PlanetScope satellite, revealing that the building areas were gradually replaced by the vegetation covers. The long-term reactivated deformations were explored by the multi-source satellite SAR data from ALOS-2 and Sentinel-1A/B based on time-series InSAR analysis. Cross-validation between the multi-source InSAR results showed that the ALOS-2 and Sentinel-1A/B measurements are highly correlated. Long-term spatial–temporal deformations were investigated using the Sentinel-1A/B Track 11 data between 2016 and 2022. A long stack of SAR datasets was divided into four consecutive branches based on the local engineering work plan. A general slowing down deformation trend can be observed from the time series analysis, indicating the effectiveness of local measures for maintaining the slope stability. Most importantly, seasonal fluctuations caused by changes in rainfall and Three Gorges Reservoir (TGR) water level can be clearly observed from the time series evolutions of deformation during each phase. Through the gray correlation analysis and cross wavelet analysis, it is found that the lower part of the Huangtupo landslide shows a higher correlation with the TGR water level changes, while the upper slope mainly responds to rainfall. Importantly, it is found that the lowest common power was observed at P4 since August, 2020, suggesting that the upper part of the slope has been changed to be more rainfall erosion resistant due to the effort of the drainage system and vegetation restoration from the ecological restoration project. [ABSTRACT FROM AUTHOR]

The assessment of landslide susceptibility often overlooks the influence of forests on shallow landslide mobility, despite its significance. This study delved into the impact of forest presence on shallow landslide mobility during intense rainfall in Mengdong, China. Field investigations were coupled with the analysis of pre- and post-rainfall remote sensing (RS) images to delineate landslides. The ratio of landslide height (H) to travel distance (L) from a digital elevation model (DEM) were used to calculate landslides mobility. Preceding the event, forest coverage was evaluated using the normalized difference vegetation index (NDVI) derived from multiband RS image. The research identified 1531 shallow landslides in the area, revealing a higher concentration of landslides on slopes with elevated NDVI. Results indicated that disparities in soil permeability and cohesion, generating pore water pressure (PWP), triggered clusters of shallow landslides. Shallow landslides exhibit a higher propensity on slopes with elevated NDVI. The dimensions (height and area) of these identified shallow landslides typically exhibit a positive correlation with NDVI, consequently resulting in longer travel distances for landslides occurring on higher NDVI slopes. The average H/L ratio of all identified landslides was about 0.63. H/L generally increases with NDVI and decreases with landslide area. However, due to river channel restrictions, the H/L increases with slope gradient. The findings suggest that the high permeability of areas with tree roots poses a risk to the shallow stability of slopes, yet trees contribute to mitigating landslide mobility. [ABSTRACT FROM AUTHOR]

Regional‐scale characterization of shallow landslide hazards is important for reducing their destructive impact on society. These hazards are commonly characterized by (a) their location and likelihood using susceptibility maps, (b) landslide size and frequency using geomorphic scaling laws, and (c) the magnitude of disturbance required to cause landslides using initiation thresholds. Typically, this is accomplished through the use of inventories documenting the locations and triggering conditions of previous landslides. In the absence of comprehensive landslide inventories, physics‐based slope stability models can be used to estimate landslide initiation potential and provide plausible distributions of landslide characteristics for a range of environmental and forcing conditions. However, these models are sometimes limited in their ability to capture key mechanisms tied to discrete three‐dimensional (3D) landslide mechanics while possessing the computational efficiency required for broad‐scale application. In this study, the RegionGrow3D (RG3D) model is developed to broadly simulate the area, volume, and location of landslides on a regional scale (≥1,000 km2) using 3D, limit‐equilibrium (LE)‐based slope stability modeling. Furthermore, RG3D is incorporated into a susceptibility framework that quantifies landsliding uncertainty using a distribution of soil shear strengths and their associated probabilities, back‐calculated from inventoried landslides using 3D LE‐based landslide forensics. This framework is used to evaluate the influence of uncertainty tied to shear strength, rainfall scenarios, and antecedent soil moisture on potential landsliding and rainfall thresholds over a large region of the Oregon Coast Range, USA. Plain Language Summary: Landslides are potentially destructive natural hazards that may impact topography, ecology, and important infrastructure. Often, previously triggered landslides are used to better understand where landslides may occur in the future, but in some regions, previous landslides may be poorly documented or characterized. In lieu of these data, models capturing the physics tied to landsliding may be paired with digital topography to predict landslide potential across landscapes. However, existing models are limited in their ability to efficiently capture the realistic geometry of three‐dimensional (3D) landslides across large landscapes. This study presents RegionGrow3D, a new model that identifies slope instabilities throughout large regions, and then grows those instabilities into landslides of previously unknown geometry by balancing forces within the underlying soil. The model is applied to a region in the Oregon Coast Range, USA to develop empirical relationships between landslide area, volume, and frequency for a range of rainfall scenarios and to determine the amount of rainfall required to trigger landslides on specific terrain features. Furthermore, because soil parameters are highly uncertain at this spatial scale (≥1,000 km2), a 3D landslide model is used to forensically assess soil strength from previously documented landslides in the area. Key Points: RegionGrow3D is a regional‐scale three‐dimensional slope stability model that grows discrete landslide volumes to achieve force equilibriumRegionGrow3D is parameterized using a range of input parameters to quantify the size, location, and likelihood of landslide initiationModeled landslides are used to quantify geomorphic scaling laws and rainfall thresholds that consider model input uncertainty [ABSTRACT FROM AUTHOR]

In slopes where high pore water pressure exists, deep counterfort drains (also called drainage trenches or trench drains) represent one of the most effective methods for improving stability or mitigating landslide risks. In the cases of deep or very deep slip surfaces, this method represents the only possible intervention. Trench drains can be realized by using panels or secant piles filled with coarse granular material or permeable concrete. If the trenches are adequately "socket" into the stable ground (for example sufficiently below the sliding surface of a landslide or below the critical slip surface of marginally stable slopes) and the filling material has sufficient shear strength and stiffness, like porous concrete, there is a further increase in shear strength due to the "shear keys" effect. The increase in shear strength is due both to the intrinsic resistance of the concrete on the sliding surface and the resistance at the concrete–soil interface (on the lateral surface of the trench). The latter can be very significant in relation to the thickness of the sliding mass, the "socket depth", and the spacing between the trenches. The increase in shear strength linked to the "shear keys effect" depends on the state of the porous concrete–soil interface. For silty–clayey base soils, it is very significant and is of the same order of magnitude as the increase in shear resistance linked to the permanent reduction on the slip surface in pore water pressure (draining effect). This paper presents the results of an experimental investigation on the shear strength at the porous interface of concrete and fine-grained soils and demonstrates the high significance and effectiveness of the "shear keys" effect. [ABSTRACT FROM AUTHOR]

Landslides are one of the most common geohazards, posing significant risks to infrastructure, recreation, and human life. Slope stability analyses rely on detailed data, accurate materials testing, and careful model parameter selection. These factors are not always readily available, and estimations must be made, introducing uncertainty and error to the final slope stability analysis results. The most critical slope stability parameters that are often missing or incompletely constrained include slope topography, depth to water table, depth to failure plane, and material property parameters. Though estimation of these values is common practice, there is limited guidance or best practice instruction for this important step in the analysis. Guidance is provided for the estimation of: original and/or post-failure slope topography via traditional methods as well as the use of open-source digital elevation models, water table depth across variable hydrologic settings, and the iterative estimation of depth to failure plane and slope material properties. Workflows are proposed for the systematic estimation of critical parameters based primarily on slide type and scale. The efficacy of the proposed estimation techniques, uncertainty quantification, and final parameter estimation protocol for data-sparse landslide analysis is demonstrated via application at a landslide in Colorado, USA. [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]

The process of rainwater infiltration into unsaturated multi-layered slopes is complex, making it extremely difficult to accurately predict slope behaviors. The hydrological mechanisms in multi-layered slopes could be significantly influenced by the varying hydraulic characteristics of different soils, thus influencing slope stability. A numerical model based on Hydrus 2D was constructed to investigate the hydrological mechanisms of multi-layered slopes under different slope inclinations and rainfall intensities. The results revealed hydraulic processes in response to rainfall in unsaturated multi-layered slopes, in which layered soils retard the advance of wetting fronts and affect seepage paths in the slope. The results also showed the characteristics of hydraulic parameters, including pore water pressure and moisture content, under different conditions, and explained the crucial factors at play in maintaining slope stability. [ABSTRACT FROM AUTHOR]

Landslide hazards pose a significant threat to lives and infrastructure, especially in mountainous regions like the Three Gorges Reservoir area. While the mechanisms driving landslide initiation and progression in reservoir environments are not fully understood. This study aimed to leverage the capabilities of Sentinel-1 satellite imagery and the Small Baseline Subset Interferometric Synthetic Aperture Radar (SBAS-InSAR) technique to detect and monitor potential landslide deformations in Yunyang County, Chongqing, China. We utilized Sentinel-1 data acquired between January 1, 2020, and December 28, 2022, to generate deformation velocity maps. Twelve potential landslides were identified, primarily concentrated near residential areas and along the Yangtze River. Precipitation emerged as the primary driver of surface deformation and landslide initiation, with potential landslides in residential vicinities and along the river exhibiting significantly higher deformation rates during the wet season compared to the dry season. These sites are susceptible to slope failures and geological disasters upon reaching critical antecedent rainfall thresholds, highlighting the necessity for continuous monitoring. Other potential landslides maintained consistent deformation rates across seasons but experienced brief accelerations following heavy precipitation events. Notably, potential landslides adjacent to the Yangtze River experienced accelerated deformation during periods of significant river water level reductions, suggesting that the river's cyclical water level fluctuations influence slope stability. The study demonstrated the effectiveness of SBAS-InSAR in detecting millimetric deformations in incipient landslides, a crucial step in averting landslide disasters and ensuring public safety. [ABSTRACT FROM AUTHOR]

Landslides, one of the natural disaster problems, occur due to slope stability triggered by natural or human activities. Once such mass movements have begun, they are challenging to stop and, in some cases, almost impossible. Geophysical methods are very effective in determining the character and mechanical properties of landslides with a high resolution before or after mass movement. This study aims identifying the landslide that tends to continue in the Çamlıca neighborhood of the Hendek district of Sakarya province by electrical resistivity (ERT), surface waves analysis (MASW-ReMi), and mechanical soil drilling. The low resistivity and low shear wave velocity (Vs) unit in the geophysical sections was determined as a saturated clayey thick cover layer from the borehole log. This clayey unit causes mass movement on the slip surface. Andesite-basalt-containing bedrock unit under the slip surface has been identified as having high resistivity and high velocity in geophysical sections. The integrated use of geophysical methods in this landslide, determined as the progressive mechanism, contributed significantly to the realistic modeling of the landslide internal structure. [ABSTRACT FROM AUTHOR]

In geotechnical analysis, the factor of safety (FOS) is crucial for slope stability assessment. Traditional methods often overlook the nuances of partial slope instability. Accurately determining geotechnical parameters for FOS in complex simulations is challenging and resource-intensive. The limit equilibrium method (LEM), considering unit weight, cohesion, and internal friction angle, is used to address this. This study focuses on the Jiuxianping landslide, analyzing its stability and failure behavior. Utilizing the Bayesian theorem, the study back-analyzes shear strength parameters, considering partial instability and uncertainties in the Janbu corrected method. The parameters' posterior distribution is determined using the Markov Chain Monte Carlo (MCMC) method and Multivariate Adaptive Regression Splines (MARS) for efficient sampling. These parameters are then used for precise FOS calculation at the critical point of partial instability, corroborated by 2021 data from the Jiuxianping landslide. The study finds that while the entire slope remains stable, partial instability caused by long-term water erosion significantly lowers the FOS about 10.9%, highlighting its critical impact on overall slope stability. [ABSTRACT FROM AUTHOR]

This paper coupled a water-air two-phase hydrodynamic (WATPH) model with the Iverson's method to analyze the influence of the Lisse effect on the fast groundwater pressure (Pw) response and the slope stability. Furthermore, the sensitivities of the driving force and loess soil parameters were investigated. Results showed that the WATPH model simulated the height and rise of the depth to the water table reasonably well. The depth to water table before rainfall (H0) had a significant impact on the Lisse effect and the slope stability. When the H0 was less than approximately 1 m, the rainfall triggered a significant Lisse effect and decreased the slope factor of safety (Fs). When the rainfall intensity (Ri) was higher than the saturated hydraulic conductivity (Ks), the Lisse effect and the Fs slightly changed with the increase of the Ri, and the slope tended to be unstable with continuous rainfall. With increasing Ks, the Lisse effect noticeably increased, and the minimum Fs quickly decreases. The analysis of the normalized sensitivity coefficient revealed that H0 had a dramatic impact on the Lisse effect and loess slope stability. The different Ri and Ks values had prominent influences on the Lisse effect and slight impacts on Fs. [ABSTRACT FROM AUTHOR]

Submarine hydrate mining can trigger geological disasters, including submarine landslides and seafloor subsidence due to excess pore pressure and weakened layers, which may potentially lead to the reactivation of faults and increased seismic activity. However, current research encounters challenges in assessing geotechnical issues associated with long-term and large-scale production from well grids located in sloped areas. Limited by the complexity of the hydrate sediment, a multifield coupled numerical model of hydrate slope in the Shenhu area was established. Utilizing the modified Mohr–Coulomb model as the constitutive model for hydrate-bearing sediments to track the dynamic reduction in strength and employing the shear strength method to assess submarine slope stability, a series of depressurization strategies are applied to evaluate the risks associated with submarine landslides and seafloor subsidence. Results show that the hydrate dissociation tends to stagnate after a period of mining. The strength of the hydrate decomposed area is severely reduced, and a volume deficit occurs in this area, causing formation displacement. The peripheral region of the decomposed area is compacted by high stress, resulting in a serious decrease in permeability and porosity, which limits the continued decomposition of hydrates. The large-scale submarine landslides with hydrates decomposition will not appear in this block. However, several meters' seafloor subsidence over a wide range risks engineering safety significantly. The amount of seafloor subsidence in the first 50 days is approximately half of the final settlement. A higher production pressure drop can speed up the recovery rate while resulting in more significant seafloor subsidence and slippage. Therefore, the balance between mining speed and formation stability needs more research work. [ABSTRACT FROM AUTHOR]

Legacy colliery spoil tip failures pose a significant hazard that can result in harm to persons or damage to property and infrastructure. In this research, the 2020 Wattstown tip landslide caused by heavy rainfall was examined to investigate the likely mechanisms and developmental factors contributing to colliery spoil tip failures in Welsh coalfields. To achieve this, an integrated method was proposed through the combination of remote sensing mapping, stability chart analysis, 2D limit equilibrium (LE) modelling, and 3D finite difference method (FDM) analysis. Various water table geometries were incorporated into these models to ascertain the specific groundwater condition that triggered the occurrence of the 2020 landslide. In addition, sensitivity analyses were carried out to assess the influence of the colliery spoil properties (i.e., cohesion, friction angle, and porosity) on the slope stability analysis. The results indicate that the landslide was characterised by a shallow rotational failure mode and spatially constrained by the critical water table and an underlying geological interface. In addition, the results also imply that the landslide was triggered by the rise of water table associated with heavy rainfall. Through sensitivity analysis, it was found that the properties of the colliery spoil played an important role in confining the extent of the landslide and controlling the process of its development. The findings underscore the detrimental effects of increased pore pressures, induced by heavy rainfall, on the stability of colliery tips, highlighting the urgent needs for local government to enhance water management strategies for this region. [ABSTRACT FROM AUTHOR]

AbstractHorizontal wells have the advantages of high production, considerable access to reserves, and effective sand production control; thus, they are potential well types for hydrate exploitation. In the process of hydrate mining, the decomposition of hydrate will cause the deterioration of the mechanical properties of the reservoir, which may induce submarine landslides, especially in the case of multiple horizontal wells, and the risk of submarine landslides is further increased. Therefore, it is necessary to study the influence of the horizontal well pattern adopted for hydrate mining on the stability of submarine slopes. First, a triaxial mechanical experiment of gas hydrate-containing sediments was carried out, and the mechanical parameters of the hydrate-containing sediments were obtained. Second, a thermal-fluid-solid multifield coupling model considering the hydrate phase transition during the production process was established. Finally, on the basis of the finite element strength reduction method, a slope stability evaluation model for hydrate extraction from a horizontal well pattern was established, and the influence of hydrate extraction from horizontal wells on the stability of submarine slope was analyzed. The results show that the peak strength, elastic modulus and cohesion of gas hydrate-containing sediments increase with increasing hydrate saturation. In the process of hydrate exploitation via horizontal wells, with the reduction in well spacing and the increase in the number of production wells, the risk of slope instability increases. Wells positioned along the slope strike are more conducive to slope stability than those positioned perpendicular to the slope strike. The slope stability increases gradually as the slope dip decreases. When the number of wells is the same, the slope stability increases gradually with increasing well spacing and production pressure. [ABSTRACT FROM AUTHOR]

As a kind of special terrain, the landslide disaster generated by liquefiable layer slopes under earthquake has become a major engineering challenge due to its large scale and long slip distance. In order to study the seismic response and damage mode of liquefiable layer slope, this paper follows the research line of “geological generalization, physical modeling, and result analysis”, and takes the liquefiable layer slope in the upper reaches of the Yellow River Class secondary terrace as the object of study, generalizes the physical model of the slope, and carries out shaking table test. Based on the PGA amplification coefficient, Fourier analysis and HHT time–frequency characterization of the model slope, it was found that the PGA amplification coefficient increases gradually along the slope height, reaches the maximum value at the top of the liquefiable layer and then decreases gradually, which indicates that the liquefiable sand layer has an obvious energy dissipation effect, and on the horizontal direction of model slope is a tendency to the surface effect; the seismic waves at the discontinuous interface change drastically, and the Hilbert time–frequency spectrum transforms from multiple peaks to a single peak; with the increase of the intensity, the intrinsic frequency of the overall model decreases, and the high-frequency component within the liquefiable sand layer decreases from 5–15Hz to 0–5Hz, indicating that the liquefiable layer has a filtering effect; the damage process of the liquefiable layer slope is the tensile crack at the top of the slope — seismic subsidence at the top of the slope — the shear yielding at the angle of the slope — shear surface penetration at the slope face — overall slope instability and flow-slip damage. The research results will provide a reference for the study of the disaster mechanism of the liquefiable layer slope. [ABSTRACT FROM AUTHOR]

A seismic-induced landslide is a common geological catastrophe that occurs in nature. The Wangjiayan landslide, which was triggered by the Wenchuan earthquake, is a typical case in point. The Wanjiayan landslide caused many casualties and resulted in enormous property loss. This study constructs a simple surficial failure model based on the upper bound approach of three-dimensional (3D) limit analysis to evaluate the slope stability of the Wangjiayan case, while a traditional two-dimensional (2D) analysis is also conducted as a reference for comparison with the results of the 3D analysis. A quasi-static calculation is used to study the effect of the earthquake in terms of horizontal ground acceleration, while a parametric study is conducted to evaluate the critical cohesion of slopes. Rather than employing a 3D analysis, using the 2D analysis yields an underestimation regarding the safety factor. In the Wangjiayan landslide, the difference in the factors of safety between the 3D and 2D analyses can reach 20%. The sliding surface morphology as determined by the 3D method is similar to actual morphology, and the parameters of both are also compared to analyze the reliability of the proposed 3D method. [ABSTRACT FROM AUTHOR]

Rainfall-induced slope failures and landslides pose significant hazards worldwide, impacting various regions, including the Kurumbadi area of Nilgiris, Tamil Nadu, India. Despite the region's vulnerability to such disasters, limited research has addressed the uncertainties surrounding soil parameters, particularly in the context of slope-stability analysis. The present study aims to fill this gap by conducting reliability analysis to assess the stability of hillslopes under different rainfall patterns. It specifically investigates how variations in soil compaction, including medium dense and loose soils, influence slope stability under both advanced and recorded rainfall patterns in the Kurumbadi area. Utilizing data from numerical analyses using Fast Lagrangian Analysis of Continua (FLAC), the study conducts comprehensive reliability analysis with Response Surface Methodology (RSM) and First-order Reliability Method (FORM), to evaluate slope stability. The findings reveal that advanced rainfall patterns significantly increase the likelihood of slope failure, highlighting the region's increased vulnerability to intense rainfall events. These insights contribute valuable knowledge to the assessment of slope instability across varying rainfall intensities and durations. Furthermore, the findings support the development of proactive measures, such as early-warning systems based on predefined threshold values, to mitigate the risks associated with rainfall-induced slope failures. [ABSTRACT FROM AUTHOR]

The toppling deformation in bank slope of V-shaped Gorge reservoirs in Southwest China is very common. After the impoundment of the reservoir, geological disasters such as collapse and landslide may occur in toppling bank slope, which poses a threat to the normal operation of hydropower projects and personnel safety. Therefore, it is of great engineering significance to study its genetic mechanism and development law. The trenching of river valley is one of the main factors of bank slope toppling deformation. In the process of river action, the free face is formed on the slope, and the rock mass is unloaded to the free face, resulting in toppling. Taking the bank slope of a reservoir in the V-shaped Gorge area on the edge of the Qinghai Tibet Plateau in Southwest China as an example, this paper studies the relationship between river action and the development of toppling. According to the seven terraces formed on both banks of the river, the trenching of the river valley is divided into seven stages. The toppling development characteristics of each stage are analyzed by discrete element method. According to the development characteristics of toppling deformation category, the toppling deformation is divided into five stages, they are initial toppling deformation stage, toppling development stage, intensified toppling deformation stage, temporary stability stage and failure stage. The research results can help to determine the development type and stage of bank slope toppling deformation in V-shaped Gorge area, so as to predict its further development deformation characteristics. [ABSTRACT FROM AUTHOR]

This study investigates the geotechnical factors influencing a recent landslide event in Gera Woreda, Ethiopia. The primary objective was to identify the soil properties contributing to landslide occurrence and understand the triggering mechanisms. Field investigations, soil sampling from both affected and unaffected areas, and subsequent laboratory characterization were conducted. The analysis revealed a dominance of fine-grained soils, such as clay and silt, which are susceptible to weakening upon saturation, thereby increasing landslide susceptibility. Rainfall is identified as the primary trigger for the landslide. Numerical stability assessments using the Limit Equilibrium Method (software, Slide™) and the Finite Element Method (software, PLAXIS®) were performed to assess the stability of the slopes. The stability analysis revealed a notable decrease in the factor of safety (FS) under rising groundwater levels. For example, the FS for Slope 1 decreased from 1.42 under dry conditions to 0.73 at a 2 m groundwater depth. Similarly, Slope 2's FS decreased from 2.06 to 1.18 under similar conditions. These results emphasize that rainfall is the primary trigger for landslides in the area. To address this, the study proposes surface drainage systems and the planting of Vetiver grass to improve slope stability. These findings provide critical insights for developing proactive mitigation strategies to protect local communities and infrastructure from landslide hazards.

In mountainous regions, landslides pose significant and frequent threats, causing extensive damage due to their destructive nature and frequency, therefore determining their likely occurrence sites and environmental factors is essential for hazard assessment. The infinite slope approach characterizes slope stability using a factor of safety (FOS) to assess the likelihood of slope failure and is frequently used to estimate the occurrence of shallow landslides on soil and regolith-covered slopes. Various methods have been used to evaluate and spread uncertainty across such models. Slope failure is a significant geological occurrence brought on by topography and weather, which result in a variety of ground movements. Engineers must plan and implement measures to mitigate hazards, safeguarding both lives and property from potential risks and dangers by using an adequate stabilizing solution. Technology and software advancements have made it simpler than ever to handle challenging issues that used to require a lot of time in every profession. Over the past decade, software utilization in civil engineering has surged. GEO 5 is a versatile program gaining prominence, aiding in the resolution of diverse geotechnical challenges. Through the installation of IoT cameras in various sand and clay areas along the bank of the Mahandi River in Odisha, we have gathered the data necessary to develop the region in this case. a select selection of which we have chosen for our research. In this study, slope stability-related modules have been carefully examined and used for the analysis of slope stability. Using the GEO5 program, the geometry of the issues was established, and the study took into account several stability optimization techniques. Additionally, the cost factor of various reinforcing techniques was calculated and contrasted. [ABSTRACT FROM AUTHOR]