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Dam landslides occurred frequently during recent years, and the secondary disasters caused by it can cause great harm to local resident in an extensive area. Therefore, it is important to understand the mechanisms of dam failure. Experiments were designed to study the mechanisms of dam failure, analyze the effects of multi-factors, and establish a method for the critical condition of dam breach. The results showed that before the collapse, the existence of the notch surface accelerates infiltration and causes advancement of the speed of the wet front. The dam failure process can be divided into three stages: erosion initiation, erosion acceleration, and erosion weakening. During the breaching, three important erosion phenomena were observed including slope instability, steep slope, and collapse. Based on statistical analyses of the changes in the longitudinal slope profile and erosion rates observed during the dam failure, characteristics of erosion rate along the longitudinal profile have been summarized well. The slope of the bottom groove, size of the dam body, upstream inflow discharge, and median particle size of the dam body significantly affected the characteristics of the dam body collapse. Then, a critical water head that leads to an overtopping outburst was established based on the experimental data and theory of incipient motion of sediment, providing critical information to predict dam failure. The results of this research would be helpful to predict the disaster chain and enhance the risk management of this kind of disaster chain. [ABSTRACT FROM AUTHOR]

Volcanic eruption is known as multi-hazards to the surrounding environment and society causing the formation of lahar as the frequent hazards that shortly occurred due to airborne tephra after an eruption. Erosion triggered by rainfall on unconsolidated tephra material, such as volcanic ash, is the primary lahar initiation mechanism. The time and scale of lahars vary based on eruptions and watershed conditions. The variability of the erosion process is driven by a set of local factors including the grain size and spatial distribution of volcanic ash thickness, slope, and rainfall intensity. Laboratory simulation experiments were conducted in a 3.00 m long, 0.75 m wide, and 0.50 m deep flume to study the relationship of volcanic ash erosion rate to three driven parameters, namely slope, rainfall intensity, and volcanic ash thickness. Three slope gradients were selected to represent gentle (14.1%), mild (26.8%), and steep (46.6%) slopes. Meanwhile, the rainfall intensity ranged from 0.65 to 1.85 mm.min-1, and the variations of volcanic ash layer thickness were 1.00 cm; 2.50 cm; and 5.00 cm. The erosion rate model was generated from a dimensional analysis accommodating slope, rainfall intensity, flow discharge, and the ratio of critical and applied boundary shear stress as independent variables. The variable coefficients were obtained by parameter optimization of experiment data through nonlinear regression analysis. The erosion rate model performance was tested using the Nash-Sutcliffe model Efficiency (NSE), Index of Agreement (IOA), and Root Mean Square Error (RMSE). The performance of the volcanic ash erosion rate model was proven to be satisfactory with the NSE>0.75, IOA>0.95, and RMSE values ranging from 0.005 to 0.009. This model has proven applicable better for volcanic ash erosion than other erosion models which are sandy soil material-based experiments because of the specific characteristics of volcanic material itself. The volcanic ash erosion model in this study can be implemented to predict the sediment yield of tephra as part of volcanic disaster mitigation. [ABSTRACT FROM AUTHOR]

The soil is usually unsaturated in practical engineering, and the slope failure surface generally presents three-dimensional (3D) characteristics. Therefore, the traditional plane problem calculation method does not accurately describe the slope's stability and safety assessment results strengthened through frame beam anchor plates (FBAPs). This work introduces a novel approach based on the limit analysis (LA) technique for assessing the 3D stability of unsaturated soil slopes supported by FBAPs to address this issue. The slope safety factor (Fs) expression was derived based on the energy balance principle. The soil slope stability the FBAP reinforces was quantitatively expressed as a function of slope parameters. Nonlinear distribution features of soil matrix suction and effective unit weight, as well as the internal energy dissipation rate created by the anchor plate, must be taken into account when calculating the internal energy dissipation and external work rate. The impact of the 3D effect, seismic parameters, unsaturated soil characteristics, and supporting structure on slope stability was discussed. Some design suggestions for slope reinforcement are put forward. According to the findings, the suction effect's beneficial effects on stability should be considered. Slopes with a width-to-height ratio (B/H) of less than 10 should consider the 3D effect's beneficial effects. The seismic action significantly negatively impacts slope stability, while using FBAP reinforcement structures can dramatically improve slopes' static and seismic stability. [ABSTRACT FROM AUTHOR]

Loose granular materials may also exhibit instability behaviors similar to liquefaction under drained conditions, commonly referred to as diffuse instability, which can be studied through constant shear drained (CSD) tests. So far, the research on CSD in binary mixtures is still insufficient. Therefore, a series of numerical tests using the discrete element method (DEM) were conducted on binary mixtures under CSD path. The possible model of instability is categorized into type I and type II, type I instability occurs prior to reaching the critical state line (CSL), whereas type II instability occurs after exceeding the CSL. The study analyzes the macroscopic instability behavior and the impact of fine content (FC) on macroscopic instability behavior. The numerical results show that as FC increases, the slope of the instability line (IL) increases initially and then falls in the p‐q plane. In the e‐p plane, the IL decreases initially and then ascends. The instability type of the binary mixtures is influenced not only by relative density but also by FC. The stability index increased first and then decreased with the increase of FC. The microscopic origin of binary mixtures instability is explored by investigating the fabric‐stress relationship. The collapse of the weak contact sub‐network triggers the specimen instability, while the strong contact sub‐network dictates the difficulty of achieving instability. FC influences the evolution of fabric anisotropy of the strong and weak contact networks, thereby controlling the macroscopic instability behavior of binary mixtures. [ABSTRACT FROM AUTHOR]

Rock and soil strength profoundly influences the stability of open-pit mine slopes. Traditional slope design, based on limited drilling data, often disregards inherent uncertainties. Effectively utilizing new sample information from mining operations poses a challenge, hindering dynamic and differentiated design for the entire perimeter slope. To address this, we propose a dynamic optimization method considering rock mass strength uncertainty for the entire perimeter slope. Our approach involves designing slope angles separately in different zones, while thoroughly considering decision-makers' preferences. Furthermore, we delegate the final adjustment authority of slope angles within the safety permissible range to on-site decision-makers. Compared to traditional methods, our dynamic design method incorporates rock mass strength uncertainty into slope evaluation while also accounting for decision-makers' safety and economic preferences. Through a case study of a specific open-pit mine, our proposed dynamic design method increases the overall slope angle by approximately 2.5°, fully accommodating the influence of on-site decision-making preferences on slope design. This article introduces a new method of dynamic optimization of open-pit mine slope based on simplified observation method, which improves the flexibility of decision-making and realizes the differential design of the whole surrounding slope. [ABSTRACT FROM AUTHOR]

In this work, intelligent numerical models for the prediction of debris flow susceptibility using slope stability failure factor of safety (FOS) machine learning predictions have been developed. These machine learning techniques were trained using novel metaheuristic methods. The application of these training mechanisms was necessitated by the need to enhance the robustness and performance of the three main machine learning methods. It was necessary to develop intelligent models for the prediction of the FOS of debris flow down a slope with measured geometry due to the sophisticated equipment required for regular field studies on slopes prone to debris flow and the associated high project budgets and contingencies. With the development of smart models, the design and monitoring of the behavior of the slopes can be achieved at a reduced cost and time. Furthermore, multiple performance evaluation indices were utilized to ensure the model's accuracy was maintained. The adaptive neuro-fuzzy inference system, combined with the particle swarm optimization algorithm, outperformed other techniques. It achieved an FOS of debris flow down a slope performance of over 85%, consistently surpassing other methods. [ABSTRACT FROM AUTHOR]

ABSTRACT Turbidity current behaviour is affected by interactions with seafloor topography. Changes in flow dynamics will depend on the orientation and gradient of the topography, and the magnitude and rheology of the incoming flow. A better understanding of how unconfined turbidity currents interact with topography will improve interpretations of the stratigraphic record, and is addressed herein using three‐dimensional flume tank experiments with unconfined saline density currents that enter a horizontal basin before interacting with a ramp orientated perpendicular to flow direction. The incoming flow parameters remained constant, whilst the slope angle was independently varied. On a 20° slope, superelevation of the flow and flow stripping of the upper, dilute region of the flow occurred high on the slope surface. This resulted in a strongly divergent flow and the generation of complex multidirectional flows (i.e. combined flows). The superelevation and extent of flow stripping decreased as the slope angle increased. At 30° and 40°, flow reflection and deflection, respectively, are the dominant flow process at the base of slope, with the reflected or deflected flow interacting with the parental flow, and generating combined flows. Thus, complicated patterns of flow direction and behaviour are documented even on encountering simple, planar topographies orientated perpendicular to flow direction. Combined flows in deep‐water settings have been linked to the interaction of turbidity currents with topography and the formation of internal waves with a dominant oscillatory flow component. Here, combined flow occurs in the absence of an oscillatory component. A new process model for the formation and distribution of hummock‐like bedforms in deep‐marine systems is introduced. This bedform model is coupled to a new understanding of the mechanics of onlap styles (draping versus abrupt pinchout) to produce a spatial model of gravity‐current interaction, and deposition, on slopes to support palaeogeographical reconstructions. [ABSTRACT FROM AUTHOR]

Slope instability, driven by factors such as rainfall, seismic activity, and human influence, presents a pervasive hazard worldwide. Timely assessment of slope stability and accurate identification of its most critical slip surface are important for slope safety early warning and management. Currently, for the slope reliability analysis by the strength reduction method (SRM), the critical failure path is approximately determined through visualization techniques, which is not sufficiently precise. Therefore, this study proposes a critical failure search method based on SRM for slope reliability analysis, aiming to accurately identify the critical slip surface. The critical failure path is considered as the path with the maximum plastic dissipative energy density (PDED) and is searched in the constructed weighted graph based on the dissipated energy of the slope. This proposed method is further applied with an engineering slope to find the critical failure path and assess its reliability during and after construction. The searched critical failure path lies within the approximate range obtained through conventional visualization methods. Finally, a reliability prediction model consisting of time, rainfall, and deformation component is further constructed, which allows rapid estimation of the slope reliability through available monitor data. The results of reliability analysis indicate that construction disturbances have a significant impact on slope stability, along with other factors such as rainfall and creep. [ABSTRACT FROM AUTHOR]

Urbanization and climate change are contributing to severe flooding globally, damaging infrastructure, disrupting economies, and undermining human well-being. Approaches to make cities more resilient to floods are emerging, notably with the design of flood-resilient structures, but relatively little is known about the role of urban form and its complexity in the concentration of flooding. We leverage statistical mechanics to reduce the complexity of urban flooding and develop a mean-flow theory that relates flood hazards to urban form characterized by the ground slope, urban porosity, and the Mermin order parameter which measures symmetry in building arrangements. The mean-flow theory presents a dimensionless flood depth that scales linearly with the urban porosity and the order parameter, with different scaling for disordered square- and hexagon-like forms. A universal scaling is obtained by introducing an effective mean chord length representative of the unobstructed downslope travel distance for flood water, yielding an analytical model for neighborhood-scale flood hazards globally. The proposed mean-flow theory is applied to probe city-to-city variations in flood hazards, and shows promising results linking recorded flood losses to urban form and observed rainfall extremes. A statistical mechanics approach unveils how urban layout influences flood hazards linking flood risk to factors like ground slope, porosity, building arrangement symmetry, and chord length, offering a scalable model applicable worldwide. [ABSTRACT FROM AUTHOR]

Shallow groundwater or narrow-deep lined canals have suffered the vertical frost heave at the top of the canal in cold regions. The lining fracture and whole uplift frost damage are also prone to occur, leading to the low stability of the canal at low temperature. However, the existing engineering models of canal frost heave have focused only on the normal one of the canal slope. This study aims to consider the combined effect of vertical frost heave on the top of the canal and normal frost heave on the slope. A mechanical engineering model was established to consider the canal frost heave. Sensitive soil was selected to simulate the moisture-heat-mechanical coupling numerical models in the canal. The frost heave was then used under different dip angles of the slope, width-to-depth ratios, and groundwater levels. The maximum tensile stress was calculated to locate the different freezing depths and dip angles of the slope during frost-jacking. The specific mechanism of canal lining was then explored to clarify the distribution of vertical and normal frost heave during frost-jacking. The internal force of canal lining plate and frost-jacking strength of canal slope were evaluated to calculate the critical slope length, critical groundwater level, and dangerous location of frost-jacking failure. Finally, the engineering mechanics model was proposed to test the actual case. The experimental data was in agreement with the field observation. The results show that the freezing counterforce was failed to offset the upper tangential frost-jacking force, particularly for the lower lining with the short slope length. The lining was also suffered from the jacking disease as a whole. Otherwise, a frost-jacking force was formed inside the lining. The greater the freezing depth and the dip angles of the slope were, the larger the area of the lining bearing the upward tangential force was, and the greater the frost-jacking tensile stress was. The position of the maximum tensile stress caused by jacking was shifted to the lower part of the canal with the increase of freezing depth and inclination angle of the canal slope. The maximum tensile stress was negatively related to the groundwater level. The critical water level of the lining was the critical groundwater level of the original ground frost heave. At the same time, the frost heave of the original ground was a necessary and insufficient condition for the canal to produce the frost pull. The numerical fitting indicated that the minimum curvature radius of the frost depth line at the top of the canal increased with the increase of frost depth and dip angles of the slope. The depth of frost shared a linear relationship with the minimum curvature radius. The dip angles of the slope exhibited a greater impact on the fitting slope. The maximum error of tensile stress was verified by the numerical model to be 1.5%. The frost-jacking position error was within 16.01%. Therefore, the slope range of the freezing line radius function was 1.047 to 4.040 in the soil conditions of the Ningxia irrigation area. There were the overall uplift pattern of small canal and the cracking failure pattern of large canal linings. The damage mechanism was then clarified to prevent and control the anti-frost heave of canal lining. The finding can also provide a strong reference for engineering design and code revision. [ABSTRACT FROM AUTHOR]

Co‐based catalysts have been widely used in oxygen evolution reaction (OER) because of their low price and excellent catalytic performance. Herein, strategies of ion leaching and surface reconstruction to form more catalytic active sites are proposed, and accordingly improving the intrinsic activity of OER catalyst. First, the Co‐metal–organic frameworks (MOFs)/Ni precursors are synthesized on Ni foam by hydrothermal method. Then, the second hydrothermal reaction is carried out in sodium metavanadate solution, and a highly active V‐doped Co‐MOFs/Ni OER catalyst with particle coating is obtained. The results show that V‐doped Co‐MOFs/Ni in 1 m KOH solution shows excellent performance, that is, low overpotential of 253 mV at 10 mA cm−2, Tafel slope of 56 mV dec−1, small charge transfer impedance, large electrochemically active area of 1.71 mF cm−2, and good stability. Inductively coupled plasma‐atomic emission spectrometry measurements confirm that the V ions play a dominant role in leaching, while the Co ions negligibly contribute to the leaching. This work paves an alternative approach for advancing the synthesis of high‐efficiency nonprecious OER catalysts by such a facile green method. [ABSTRACT FROM AUTHOR]

Rock slope failures pose significant challenges in geotechnical engineering due to the intricate nature of rock masses, discontinuities, and various destabilizing factors during and after excavation. In mining industries, such as national cement factories, multi-benched excavation systems are commonly used for quarrying. However, cut slopes are often designed with steep angles to maximize economic benefits, inadvertently neglecting critical slope stability issues. This oversight can lead to slope instability, endangering human lives and property. This study focuses on analyzing the stability of existing quarry cut slopes, estimating their final depth, and conducting a parametric study of geometric profiles including bench height, width, face angle, and rump width. Kinematic analysis helps identify potential failure modes. The results reveal that the existing quarry cut slope is prone to toppling, wedge failure, and planar failure with probabilities of 42.68%, 19.53%, and 14.23%, respectively. Numerical modeling using the finite element method (Phase2 8.0 software) was performed under both static and dynamic loading conditions. The shear reduction factor (SRF) of the existing quarry cut slope was 1.01 under static loading and 0.86 under dynamic loading. Similarly, for the estimated depth, the SRF was 0.82 under static loading and 0.7 under dynamic loading. These values indicate that the slope stability falls significantly below the minimum acceptable SRF, rendering it unstable. The parametric study highlights the face angle of the bench as the most influential parameter in slope stability. By adjusting the bench face angle from 90° to 75°, 70°, and 65°, the SRF increased by 31.6%, 35.4%, and 37.9%, respectively. Among these, a 70° bench face angle is recommended for optimal stability with a SRF of 1.27 under static loading and 1.18 under dynamic loading. [ABSTRACT FROM AUTHOR]

Tracked robots are useful in disaster recovery missions owing to their high traversability. However, even tracked robots find traversing terrains with obstacles such as rocks difficult. Particularly, unfixed obstacles pose problems. Therefore, this study aims to generate motion for tracked robots to go over unfixed obstacles on slopes by utilizing a reinforcement learning (RL) approach. In RL, rewards are important to make robots learn optimal policies for various tasks. Hence, a new definition of going over an unfixed obstacle is proposed. Based on the proposed definition, a sparse reward is designed to motivate the robot to go over the obstacle while avoiding the large sliding-down phenomenon responsible for the failure of going over and the large directional deviation of the robot. In our experiment, a robot is trained in a dynamic simulator and it attempts to go over a spherical unfixed obstacle under various environmental conditions: radius of the obstacle, slope degree, and initial position of the obstacle. We verify that the success rate converges to a high value and the robot successfully generates motions to go over the spherical unfixed obstacle. [ABSTRACT FROM AUTHOR]

[Objective] The aims of this study are to elucidate the response of soil and water loss resulting from slag dumping engineering disturbances during railway construction, and to unveil the impact of slag accumulation and vegetation restoration on soil and water loss at a slope scale in the ecologically fragile mountain meadow region of eastern Xizang. [Methods] Four slope types such as undisturbed, mildly disturbed, severely disturbed, and disturbed then covered with soil restoration were selected. The in-situ runoff plots were established. The process of sediment production and loss on slope was monitored by artificially simulated rainfall experiment. [Results] (1) The quantity of spattering on the slope increased with the intensity of disturbance, with the amount on the downhill side being approximately 1.14 to 2.67 times greater than that on the uphill side. (2) The initial flow generation time for the lightly disturbed slope, heavily disturbed slope, and covered slope reduced from 53.8% to 66.7%, 34.6% to 46.7%, and 86.7% to 92.9%, respectively. (3) The flow production rates for the undisturbed slope, lightly disturbed slope, heavily disturbed slope, and covered slope ranged from 44 to 86 ml/(min m²), 104 to 147 ml/(min.m²), 200 to 373 ml/(minm²), and 46 to 95 ml/(minm²), respectively. The sediment production rates ranged from 0.026 to 0.055 g/(min m²), 0.05 to 0.098 g/(min m²), 1.034 to 2.189 g/(min m²), and 0.047 to 0.077 g/(min m²), respectively. [Conclusion] The soil and water conservation capacity of the restored slope has been significantly improved in comparison to the lightly disturbed and heavily disturbed slopes. However, there still exists a disparity between the undisturbed slope and the covered slope. Therefore, additional vegetation or engineering measures need to be implemented to restore the disturbed slope effectively. [ABSTRACT FROM AUTHOR]

Weathered rock (especially granite) slopes are prone to failure under the action of rainfall, making it necessary to study the response of weathered rock slope to rainfall infiltration for landslide prevention. In this study, a series of model tests of weathered rock slope under different conditions were conducted. The matric suction, volumetric water content, earth pressure and deformation of slope were monitored in real time during rainfall. The response of the slope to rainfall infiltration, failure process and failure mode of slope under different conditions were analyzed, and the early warning criterion for the failure of weathered rock slope caused by rainfall was studied. The results show that the slope deformation evolution process under rainfall condition was closely related to the dissipation of matric suction. When the distribution of the matrix suction (or water content) of slope met the condition that the resistance to sliding of the slip-mass was overcome, the displacement increased sharply and landslide occurred. Three factors including rainfall process, lithologic condition and excavation condition significantly affect the response of weathered rock slope to rainfall. It can be found from the test results under different conditions that compared with intermittent rainfall condition, the rainfall intensity and infiltration depth were smaller when the slope entering accelerated deformation stage under the condition of incremental rainfall. The accumulated rainfall when weathered clastic landslide occurring was greater than that of weathered granite, which results in greater disaster risk. The excavation angle and moisture distribution of a slope were the main factors affecting the stability of a slope. In addition, the evolution processes and critical displacement velocities of slopes were studied by combining the deformation curves and matrix suction curves, which can be used as reference for early warning of rainfall-induced weathered rock landslide. [ABSTRACT FROM AUTHOR]

Anchor reinforced vegetation system (ARVS) comprises high performance turf reinforcement mats (HPTRM), vegetation and anchors. It is a new attempt to apply the system in expansive soil slope protection. The goal of this paper was to evaluate the effectiveness of ARVS in protecting newly excavated expansive soil slopes. The field tests on the bare slope, grassed slope and ARVS protective slope were carried out, including natural and artificial rainfall. During the test, the soil water content, soil deformation, and anchor axial force were monitored, and then the slope protection mechanism of ARVS was analyzed. It was found that ARVS can effectively protect expansive soil slopes compared with bare slopes and grassed slopes. The vegetation and HPTRM form a reinforced turf, and the anchors fix it to the slope surface, thus restraining the expansion deformation. The axial force on the anchor of ARVS includes frictional resistance and tensile force transmitted by HPTRM, which is maximum at the early stage of support. The neutral point of the anchor of ARVS moves deeper under atmospheric action, but the vegetation and HPTRM on the slope surface can limit this movement. [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]

The Holy Monastery of Panagia Spiliani is an important religious monument of the Aegean islands. The monastery is built on a steep rocky hill in the Castle of Mandraki on Nisyros island. On the slopes of the foundation area of the monastery, landslides have occurred in the past, mainly rockfalls and slides, while the risk of new similar phenomena in the future is high. To assist the geohazard assessment and mitigation design works, a combined survey using Terrestrial Laser Scanning (TLS) and Unmanned Aerial Vehicle (UAV) photogrammetry was implemented. Besides capturing the detailed morphology within high-resolution 3D point clouds, the main engineering geological units were identified on the slopes, while critical structural ground elements and unstable blocks were mapped in detail. These were quantified in terms of geotechnical parameters, and the engineering geological model of the hill was finalised and presented in an engineering geological map and cross sections. The mitigation measures are targeted towards the stabilisation of the wider area of the upper slope, hence the stability of the monastery and its surroundings risk elements, as well as the support of specific, large- to small-scale unstable rock blocks on the whole slope area, securing accessibility to the main beach of the village. [ABSTRACT FROM AUTHOR]

Slope failures possess destructive power that can cause significant damage to both life and infrastructure. Monitoring slopes prone to instabilities is therefore critical in mitigating the risk posed by their failure. The purpose of slope monitoring is to detect precursory signs of stability issues, such as changes in the rate of displacement with which a slope is deforming. This information can then be used to predict the timing or probability of an imminent failure in order to provide an early warning. Most approaches to predicting slope failures, such as the inverse velocity method, focus on predicting the timing of a potential failure. However, such approaches are deterministic and require some subjective analysis of displacement monitoring data to generate reliable timing predictions. In this study, a more objective, probabilistic-learning algorithm is proposed to detect and characterise the risk of a slope failure, based on spectral analysis of serially correlated displacement time-series data. The algorithm is applied to satellite-based interferometric synthetic radar (InSAR) displacement time-series data to retrospectively analyse the risk of the 2019 Brumadinho tailings dam collapse in Brazil. Two potential risk milestones are identified and signs of a definitive but emergent risk (27 February 2018-26 August 2018) and imminent risk of collapse of the tailings dam (27 June 2018-24 December 2018) are detected by the algorithm as the empirical points of inflection and maximum on a risk trajectory, respectively. Importantly, this precursory indication of risk of failure is detected as early as at least five months prior to the dam collapse on 25 January 2019. The results of this study demonstrate that the combination of spectral methods and second order statistical properties of InSAR displacement time-series data can reveal signs of a transition into an unstable deformation regime, and that this algorithm can provide sufficient early-warning that could help mitigate catastrophic slope failures. [ABSTRACT FROM AUTHOR]

Slope failure rates may be exacerbated by increased precipitation patterns associated with climate change. Such events are extremely disruptive for local communities affected. Rapid engineering remediation solutions generally require immediate site characterization, including information on depth to intact bedrock and groundwater conditions – often on dangerous or still‐failing slopes. Horizontal‐to‐vertical spectral ratio is a low‐impact technique capable of rapidly providing key information on the subsurface. Here we develop a robust workflow for constrained minimization of horizontal‐to‐vertical spectral ratio data and develop constrained horizontal‐to‐vertical spectral ratio profiling methodologies. We present results from a number of landslide sites in eastern Australia and demonstrate the utility of horizontal‐to‐vertical spectral ratio in delineating both fractured‐rock aquifers at high‐risk sites and colluvium–bedrock contact on active landslide sites, where traditional seismic methods were not practical. [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 introduces a numerical investigation into the stability analysis of soil nailed slopes. It establishes a simplified framework within the limit equilibrium method, focusing on the physical distribution of tension force along nails. MATLAB® was adapted for the Analysis of Soil Nailed Walls (ASNW) based on Bishop's method, with major command loops optimized through 'array operations'. Employing K-fold cross-validation, five regression models predicted the maximum tensile force (Tmax), revealing Gaussian process regression (GPR) as the best model based on root mean square error and r-squared metrics. To capture the amount of uncertainty in the nail load model, we have used a clustering method for estimating the measured Tmax. Self Organizing Map (SOM) was employed for clustering the nail load dataset. We randomly generated Tmax between the measured Tmax obtained by SOM and the predicted Tmax gained by the GPR model for each soil nail. We apply these loads in ASNW program to compute the Factor of Safety, and finally estimate system failure probability for 35 different nail layouts. A parametric study with a uniform nail layout explores the impact of nail length on system failure probability. Results show diminishing significance of nail length on failure probability beyond a nominal length. [ABSTRACT FROM AUTHOR]

Landslides are a severe geological hazard in northeastern India, particularly in Mizoram's Aizawl district. To assess this hazard, we conducted a landslide susceptibility mapping study using the frequency ratio (FR) and analytical hierarchy process (AHP) methods. Twelve factors, including slope, elevation, aspect, curvature, topographic wetness index, topographic ruggedness index, rainfall erosivity factor, geology, land use land cover, normalized difference vegetation index (NDVI), and distance to road, were considered. The final susceptibility maps were created by combining these factors, each weighted according to its importance. Since no standard classification guidelines existed, we compared different systems like GIS-based geometric interval (GIC), natural breaks (NBC), and quantile interval (QIC) with mean-standard deviation (MSC). The area was divided into five susceptibility zones: very high, high, moderate, low, and very low. We evaluated the accuracy of these systems using success rate curve (SRC) and quality sum ratio (Qs) techniques. SRC results showed similar performance for GIC, NBC, QIC, and MSC classifications. The AHP method also yielded comparable results. After analyzing the AUC under SRC and Qs, we selected the MSC classification system as the optimal approach for landslide susceptibility mapping. Notably, the distance to roads factor had the highest predictive value, highlighting its importance in identifying slope instability for effective management strategies. As landslides pose significant risks in northeastern India, and our study using FR and AHP methods, along with MSC classification, provides valuable insights for mitigating this geological hazard. [ABSTRACT FROM AUTHOR]

A method directly using rainfall records to predict a slope's potential instability is devised. The method consists of three sequential steps: identifying the critical suction stress (pore water pressure when soil is saturated) profile of a given slope, developing a rainfall intensity–duration threshold curve for the slope, and using rainfall record to determine if the threshold is reached (failure occurs) or not (no failure). It innovatively uses a slope's strength parameters and slope angle to develop the critical suction stress (tensile) or compressive pore water pressure profile where, at each depth within the slope, the effective stress reaches the failure state. Hydromechanical numerical modeling is then conducted under various rainfall intensities to identify their corresponding duration for slope failure, thus, the rainfall intensity–duration threshold curve of the slope. Two previously well-documented and studied rainfall-induced slope instability cases; one near the town of Edmonds, Washington State, and the other near the village of Rüdlingen in northern Switzerland are used to validate the method. Excellent predictions of the slope failure depth and timing are demonstrated, indicating the effectiveness of the proposed method. Because the suction stress–based rainfall intensity–duration curve is characteristic of a given slope and it can be determined a priori, the method provides a practical way to conduct real-time rainfall monitoring and predict instability for a specific slope, and a pathway to forecast instability of natural slopes in a region. [ABSTRACT FROM AUTHOR]

Soil nails and tieback anchors are used extensively for excavation support and slope stabilization; however, their performance can be complicated by limited pullout capacity or installation challenges. This paper presents the results of field load tests performed on anchorage elements with snakeskin-inspired surfaces that do not require grout and that can reduce the force required for installation. These tests evaluated the effects of the asperity geometry, soil type, and embedment depth on the anchor load transfer behavior and pullout capacity. The tests consisted of jacked installation and pullout loading in sites consisting of dense sand and structured silt. The test results in sand indicate that the installation force and pullout skin friction increase as the asperity height is increased and the asperity length is decreased. The pullout capacity of the snakeskin-inspired anchors in sand was between 1.2 and 4.2 times greater than the capacity of a reference rough anchor. In the structured silt site, disturbance during installation influenced the pullout behavior, resulting in a decrease in anchor capacity as the asperity height was increased. However, the anchor capacity with small asperity heights was greater than that of the reference rough anchor. The snakeskin-inspired anchors mobilized direction-dependent skin friction, resulting in pullout skin friction values that were as much as 3.0 and 4.5 times greater than those generated during installation in the sand and silt sites, respectively, due to mobilized passive resistances during pullout. The results indicate that the snakeskin-inspired anchors can outperform conventional driven anchors in sands. However, the possible effects of installation disturbance should be evaluated carefully in sensitive, structured soils. [ABSTRACT FROM AUTHOR]

The current active earth pressure calculation theory cannot take into account the influence of the foundation inverse slope. For the translational mode retaining wall in this paper, taking cohesive backfill as the research object, the clay within the crack depth range is equivalent to uniform overload, using the upper limit theory, establishing the energy conservation equation of the velocity field and force, and the analytical formula of the tensile crack depth and the slip surface of the cohesive backfill being obtained. By taking into account the soil arching effect, setting up the static equilibrium equation by horizontal layer analysis, deriving the active earth pressure calculation expression of cohesive backfill, it is possible to consider the influence of the basement inverse slope. In the case of cohesionless backfill, the formula can be reduced to the theoretical solution. By comparing the calculated results with the experimental values and relevant theories, this can verify the applicability of the formula. The result of research shows that, with the increase of the basement inverse slope angle, the development of the tensile crack will be promoted, the dip angle of the slip surface changes little, and the resultant force and overturning moment will decrease, which is conducive to the antisliding stability and antioverturning stability of the wall, reducing the project cost. The active earth pressure distribution of cohesionless backfill is independent of whether there is an inverse slope in the basement. The theoretical formula obtained in this paper can be used as reference for the design of the retaining wall. [ABSTRACT FROM AUTHOR]

Geosynthetic-reinforced and pile-supported embankments (GRPSEs) encompass two core components of the aforementioned reinforced embankment and the underlying composite foundation. Previous centrifuge modeling of GRPSEs generally simplified or omitted the key aspects related to the core components, which can weaken the similarity of working performance between models and prototypes. In the current study, to accurately investigate the effects of the change of pile arrangement on the overall working mechanism of GRPSEs, two groups of centrifuge model tests on GRPSEs (Groups A and B with different pile cap sizes and pile spacings) were conducted by taking into account the similarity in design of materials, geometry, and pile‒soil friction. Without simplifications and omissions of the core aspects of the composite foundation, the test models involve the embankment slope, geotechnical reinforcement, large-diameter cast-in-situ concrete pipe (PCC) piles, and soft soil foundation. It has been verified that increasing the area replacement ratio by expanding the pile-cap area and enlarging the pile spacing is an economical way to reduce the final settlement and postsettlement, allowing for more loading to be concentrated on the PCC piles with a lower pile-soil stress ratio. Additionally, the influences of the 1g model preparation and g-ring loading method were analyzed and discussed. The subsurface settlements during the embankment loading stage, as well as the total rebound deformation, were recorded, and it was found that, based on the four-stage global settlement characteristics investigation, the settlement in the embankment construction stage and the final settlement are both overestimated. This study provides essential insights into the influence of modeling stress history on the deformation in centrifuge testing and serves as a reference for the pile arrangement design of GRPSEs. [ABSTRACT FROM AUTHOR]

This study investigates the seismic vertical bearing capacity of strip footings positioned on reinforced soil structures employing a two-phase approach and the slip line method. The investigation aims to establish a slip line field and determine the critical slip surface without any assumptions of predefined surfaces. The obtained results are compared with previous studies, demonstrating a good agreement and validating the accuracy of the proposed approach. The variation of the bearing capacity factor with the horizontal seismic coefficient, soil internal friction angle, setback distance normalized by footing width, and slope incline angle. An increase in the horizontal seismic coefficient leads to a decrease in bearing capacity factor, while an increase in the soil internal friction angle has the opposite effect. The influence of the setback distance on the bearing capacity is also examined, highlighting significant improvements with increased setback distances. Additionally, the study investigates the impact of the tensile strength ratio and setback distance on the ultimate bearing capacity factor and the bearing capacity ratio. The distribution of reinforcement forces beneath the footing is analyzed and presented through contour plots, providing valuable insights into the seismic behavior of footings on reinforced soil slopes. [Display omitted] • Novel Approach for Seismic Design. • Comprehensive Parametric Analysis. • Optimized Design Considerations. • Visualization through Non-Dimensional Graphs. • Contribution to Geotechnical Knowledge. [ABSTRACT FROM AUTHOR]

This paper introduces a novel approach to analyze the seismic stability of rock slopes using the stress characteristics method (SCM). Based on a prescribed factor of safety (FS), the slope profile (SP) is forthrightly determined without involving any optimization technique. A theoretical model is developed to execute the seismic analysis by coupling the SCM with the modified pseudo-dynamic (MPD) approach. The SCM obliterates the necessity of predefined slope geometry and slip surfaces in the analysis, whereas the MPD approach captures more credible nonuniform seismic inertia forces during earthquake excitation. The generalized Hoek–Brown criterion is employed to model the nonlinear strength characteristics of the rock mass. With different recommended values of FS, chart solutions comprising SPs are presented to readily evaluate the seismic stability of rock slopes. A comprehensive parametric analysis is conducted to interpret the behavior of obtained SPs under the influence of various input parameters. The overall slope angle of the present curvilinear SPs is found to be in close agreement with that of traditional linear SPs reported in the literature. Moreover, the legitimacy of the current methodology for designing open pit mines and assessing the safety status of existing rock slopes is showcased through different case studies along with a numerical simulation of the derived SPs. [ABSTRACT FROM AUTHOR]

A certain dumping site is located near a river, and its overall height and step height are relatively high, which makes the influence of rainwater infiltration greater, posing potential hazards under rainfall conditions. Based on the stacking situation of the site and the surrounding environment, the seepage characteristics of the waste dump under rainfall conditions were studied, and the potential hazards of the waste dump slope were analyzed, then the corresponding treatment plans were proposed. The results show that with continuous rainfall, there will be a transient saturation zone on the surface of the waste dump slope and it will continue to expand to the inside of the slope. During the rainfall process, the pore water pressure of the slope increased rapidly to a positive value, then gradually stabilized, and the slope reached a saturated state. Under the influence of rainfall, the relative stability relationship of the dump slope is: slope bottom>slope top>mid-slope, and the potential hazard site is from + 85 m platform to + 170 m platform. By adding a safety platform and reducing the slope angle, the potential hazards can be effectively controlled. [ABSTRACT FROM AUTHOR]

Low impact development (LID) practices are rarely implemented on slopes due to concerns about their poor hydrological performance and the potential impact on slope stability. Implementing LIDs on slopes, involving alterations to surface topography and subsurface hydrology (specifically, the formation of a groundwater mound), can pose challenges in maintaining slope stability. However, sloping areas often require LIDs for sustainable development. It is imperative to supplement the conventional design standard to address these challenges. Before proposing specific solutions, the impact of LIDs on slope stability should be understood first. This includes quantifying the extent of changes in slope stability before and after LID implementation, as well as identifying the key factors that influence stability. To address these, we developed a numerical model in HYDRUS‐2D to simulate the hydrological and geotechnical processes of slopes implemented with a two‐stepped bioretention cell (BC) system. The numerical model was calibrated and validated using monitoring data from a stepped BC in Cincinnati, Ohio, USA. Simulation scenarios encompassed three generic slope angles (15°, 20°, and 25°) with and without BCs, two initial groundwater table positions and two inflow volumes. The hydrological process was characterized by the evolution of the groundwater mound, and the geotechnical process was quantified using the factor of safety (FoS). Our findings indicated slope cutting and filling was likely to enhance stability with an increase in the FoS of 0.1. However, the formation of groundwater mounds, resulting from exfiltration, led to an approximate 0.1–0.2 reduction in the FoS, depending on the inflow volume. The subsequent groundwater mound evolution had no further impact on stability. Ultimately, the FoS was slightly reduced by around 0–0.1 due to the combined effect of cutting and filling operations and groundwater mounds. It was generally safe to implement LIDs on 15° slopes. For steeper slopes, special design considerations are necessary, such as reducing the drainage area to strike a balance between hydrological performance and slope safety. [ABSTRACT FROM AUTHOR]

Rainfall is a pivotal factor resulting in the cause of slope instability. The traditional finite element method often fails to converge when dealing with the strongly nonlinear fluid–solid coupling problems, making it impossible to fully analyze the sliding process under the state of slope instability. Therefore, this paper uses the coupling of peridynamics (PD) and the finite element method (FEM) to propose a data exchange mode between the seepage field and the deformation field. The influencing factors of fine particle erosion during rainfall are further considered. According to the damage mechanism of the slope sliding process to the original structure of the soil, a modified erosion constitutive relationship is proposed, which takes into account the destructive effect of plastic deformation on coarse particles. Then, the influence of rainfall duration, rainfall intensity, erosion, and initial saturated permeability coefficient on slope stability was simulated and analyzed. This paper provides a novel concept for slope stability analysis and safety evaluation under rainfall conditions. [ABSTRACT FROM AUTHOR]

Pre-existing concealed goafs underneath open-pit slopes (PCO-goafs) pose a serious threat to the stability of open-pit slopes (OP-slopes), which is a common problem worldwide. In this paper, the variable weight-target approaching method, equilibrium beam theory, Pratt's arch theory, and numerical simulation are used to analyze the management solutions and stability of five PCO-goaf groups in the Nannihu molybdenum mine located in Luoyang City, Henan Province, China. The five PCO-goaf groups, numbered 1#, 2#, 3#, 4#, and 5#, are divided into four hazard classes, ranging from extremely poor to good stability. The stability of 1#, 2#, and 4# is poor and must be managed by filling, and the design strength of backfill is 1.2 MPa; caving is used to treat 3# and 5#, and the safe thickness of the overlying roof is calculated to be 10.5–41 m. After treatment, the safety coefficient of the slope is greater than 1.2, indicating that the slope is stable. This study provides insight and guidance for the safe operation of open-pit mines threatened by the existence of PCO-goafs. [ABSTRACT FROM AUTHOR]

Traditional slope stability analysis methods are time-consuming, complex, and cannot provide fast stability estimates when facing a large amount of slope cases. In this case, artificial neural networks (ANN) provide a better alternative. Based on the ANN, the particle swarm optimization (PSO) algorithm, and the principal component analysis (PCA) method, a novel PCA-PANN model is proposed. Then, a dataset of 307 slope cases covering a wide range of slope geometries and mechanical properties of geomaterial is developed. The hybrid machine learning model trained with the dataset is applied to the factor of safety (FoS) prediction of the actual slope, and three evaluation indicators are introduced to measure the prediction performance of the model. Finally, the sensitivity analysis of input parameters is carried out, and the slope protection strategy for different sensitive factors is proposed. The results show that this new model can quickly obtain the FoS and stable state of the slope without complex calculation, only by providing the relevant characteristic parameters. The correlation coefficient of the PCA-PANN model for slope stability analysis reaches more than 0.97. The sensitivity degree of influencing factors from large to small is slope angle, cohesion, pore pressure ratio, slope height, unit weight, and friction angle. [ABSTRACT FROM AUTHOR]

Watershed management measures present vital services in mitigating the risk of environmental events and conserving existing land uses on a catchment scale. Nevertheless, alongside land uses encroach on their functioning territory, and considerations regarding the failures in their structures and resulting hazards to surrounding areas have not been well documented. Therefore, the present study aimed to develop a new formula for calculating setback width (A) to conserve the structure of watershed management measures and warranty their roles and define a safety width (B) to preserve them from instability on slopes. Relations developed estimated a wide range of setback widths of A and B in detail according to the specific and environmental variables. Setback width A of mechanical measures gained based on the height and stream and its bank's slopes, in which maximum conservation width should consider for the taller check dams and weirs set up between the river banks lower than 10 degrees. Results showed that setback width A of biomechanical measures, especially in flood spreading and contour-based actions that control runoff and flash floods is wider on slopes > 20%. Setback width A of tree planting should consider 36 times the diameter of the trunk in their mature age of growth to protect the tree root system. Further, a maximum of 40 m safety setback width (B) on > 45% slope is obtained based on the erodibility factor and considering widths for firefighting and the height of falling down the tree. The present research provides guidelines for watershed managers to conserve functions of established management actions and future operations and optimize designing adjacent land uses. Observing arranging setbacks (A and B) is a critical step for land use planning and decreasing conflict of interest in lands and appropriate use of natural resources. [ABSTRACT FROM AUTHOR]

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For the first time, the present work derives explicit equations predicting the downward ground displacement of a sliding model simulating both the frictional and rotational effects under idealized acceleration pulses, in the form of simple formulas. Explicit equations allow not only accurate predictions in all cases, but also analysis of the solutions and derivation of expressions for limit cases. Half and full cycles of (i) rectangular, (ii) triangular, (iii) trapezoidal, and (iv) sinusoidal pulses and slopes both under static stability and instability are considered. For this purpose, for pulse cases (i)–(iii) recently proposed implicit analytical solutions are used, while for case (iv), first the analytical equations predicting the sliding displacement and velocity of a sinusoidal pulse in terms of time are obtained and then the time duration of motion is estimated, by using the Bhaskara approximation of the sine and cosine functions. Then, from these, solutions for the particular limit cases corresponding to the "conventional" sliding‐block model (Case A) and the post‐failure run‐off movement without any applied pulse (Case B) are derived. The results for Case A provide a useful tabulation of sliding‐block solutions, some of which are not reported in the literature. The results for Case B provide novel predictions of the time duration of motion in the case of post‐failure movement. The general solutions are analyzed graphically and the deviation from the solutions of Cases A and B is illustrated. Finally, the explicit solutions are compared to solutions of actual accelerograms. [ABSTRACT FROM AUTHOR]

The Hasankeyf Antique City contains several historical structures, ancient and new man-made caves. The dolomitic limestone exposed in the area is the main rock, but weak and not durable. The rock is deteriorated under environmental conditions such as wetting–drying and salt crystallization. The area is now partly under reservoir water of Ilısu dam. The aim of this study is to assess geoenvironmental problems of the Hasankeyf Antique City for different environmental conditions and evaluate possible mitigation measures by considering rock properties and archeological values of the site. Field and laboratory studies as well as various slope stability analyses were carried out. This study indicates that there are problems such as erosion and undercutting of the limestone, block failure associated with collapse of the man-made caves, rock weakening due to cyclic environmental conditions, and slope instabilities dominantly in the form of planar failure and rockfall. An engineering fill is constructed to mitigate the effect of harsh environmental conditions and wave effect due to reservoir water. It also works as lateral support for the steep cliffs. Already detached rocks having no archeological values are removed, and a critical block underneath the Small Palace is stabilized. Furthermore, the Small Palace being partly under reservoir level is raised in such a way that the ancient structure is well above the maximum reservoir level. On the other hand, systematic monitoring of the critical historical structures and limestone blocks should be considered to check the long-term behavior of these. [ABSTRACT FROM AUTHOR]

There are a series of gentle Piedmont slopes with a unique special stratigraphic structure in Ningzhen area of China, which manifest as clay on the surface and the underlying being primarily gravel, exhibiting a binary structure similar to fluvial facies. The number of landslides has increased significantly on gentle Piedmont slopes in this area in recent years due to an increase in extreme rainfall events. Medium to large creeping landslides are dominant, and the sliding surface is between the clay and gravel layers. The main reason is the formation of a water cushion effect due to the unique stratigraphic structure. In this paper, based on previous research, we conducted a model test to verify the influence of the water cushion effect on gentle Piedmont slopes. Meanwhile, we derived a stability equation based on the static equilibrium for gentle Piedmont slopes under three conditions and proposed two methods to derive an early warning value of the pressure head. The rationality of the early warning value was verified by comparing it with measurements. The research results provide important theoretical and technical guidance for early warning and prediction of landslides on gentle Piedmont slopes. Practical Applications: The stability equation of landslides is crucial in adequately mitigating hazards, which can provide guidelines for landslide prone areas to avoid hazards in the future. Therefore, landslide warning and prediction is of the utmost significance to ensure the safety of human life, mitigate the negative impacts on the economy, and prevent landslide hazards in gentle Piedmont slopes. Government agencies, policymakers, local authorities, and urban planners can use stability equations and early warning values to plan effective landslide monitoring and prevention measures, and make wise decisions on land-use zoning and development. By identifying areas with high landslide susceptibility through early warning values, constructing buildings and engaging in human activities in hazardous zones can be avoided, reducing the risk of damage and loss during potential landslide events. In addition, landslide warning and prediction play a crucial role in disaster risk management of landslides in gentle Piedmont slopes. Authorities can use these warning values to prioritize areas for early measures. Residents can benefit from the results by being made aware of landslide-prone areas on their property. Consequently, this study is a scientific basis and technical support for the early warning and prediction of landslides on gentle Piedmont slopes in the Ningzhen area, China. [ABSTRACT FROM AUTHOR]

An increase in precipitation due to climate change has given rise to the number of landslide occurrences. Vetiver, which is a perennial grass, is becoming increasingly popular all over the world as a vegetation-based soil bioengineering tool for preventing landslides. Sunshine Vetiver grass, also known as Chrysopogon zizanioides is noninvasive and does not compete with other indigenous plants growing in the area. Even though it is a tropical grass, Vetiver can grow in a wide range of climate conditions, including those that are quite harsh in terms of both soil and climate. The roots can grow up to 3 m in length in a dense bushy root network under optimal conditions. In this review, the authors have studied the impact of Vetiver on landslide mitigation as a climate-adaptive slope repair tool based on the research undertaken so far. Furthermore, the authors have addressed the future potential and constraints associated with the use of Vetiver for landslide mitigation. It is seen that the use of Vetiver reduces pore water pressure. The high tensile strength of Vetiver roots provides reinforcement for slopes and enhances soil shear strength. Vetiver increases saturated hydraulic conductivity and reduces surface runoff and slip surface depth. Being a vegetation-based climate-adaptive technology, this grass exhibits great promise in its ability to effectively address landslide problems. However, the magnitude of the root impact diminishes as the depth increases, rendering Vetiver a more promising remedy for shallow landslide occurrences. In addition, Vetiver grass has a wide range of practical uses due to its unique characteristics, which provide additional benefits. Employment of Vetiver is cost-effective compared with traditional engineering methods, and it requires less initial maintenance, which implies that community-based initiatives can effectively address landslide prevention through Vetiver implementation. Practical Applications: Vetiver grass has a long bushy network of roots that can grow up to 3 m in length. The Sunshine Vetiver grass is not invasive and does not compete with indigenous plants. Although Vetiver is a tropical grass, this grass can survive in various climates and soil conditions. Vetiver is a vegetation-based climate-adaptive technology that can prevent slope failure and reduce surface runoff. Additionally, growing Vetiver can generate income for local communities because the fragrant roots can be utilized in the extraction of essential oils for the perfume industry and from the manufacture and trade of other commodities derived from Vetiver. The grass's green leaves contribute to the aesthetic appeal of the landscape. Implementing Vetiver on slopes does not require heavy machinery and is cost-effective compared with traditional engineering methods. It also requires less initial maintenance, making it an ideal solution for community-based initiatives aiming to address slope failure prevention through Vetiver implementation. [ABSTRACT FROM AUTHOR]

Rainfall infiltration is the primary factor affecting slope stability, which may lead to geological hazards such as landslides, collapses, and debris flows. Thus, it is crucial to investigate the rainfall infiltration patterns of unsaturated soil slopes. During a natural rainstorm, the soil volumetric water content at various depths of a significant unsaturated soil slope model was monitored onsite. The soil-water characteristic curve parameters and saturated permeability coefficient of remolded soil were quantified, and the Van Genuchten (VG) model was utilized to forecast the unsaturated permeability coefficient. The numerical simulation method was used to simulate the field rainfall experiment. Based on the mutual verification of the field measurement and numerical simulation, rainfall simulation with different rainfall intensities was added, and its influence on rainfall infiltration depth, pore water pressure, and transient saturated zone was analyzed. The findings revealed that under the rainstorm intensity of the field rainfall test, the rainfall infiltration depth ranged from 0.2 to 0.4 m after a continuous 9-h rainfall period. As the rainfall intensity increased, the range of soil pore water pressure variations expanded, with a maximum value ranging from 9 to 140 kPa under the rainstorm rainfall intensity. By extending the duration of rainstorm rainfall intensity to 14 h, the depth of the transient saturated zone reached 0.2 m. With a duration of 20 h, it reached 0.4 m. The depth reached 0.6 m after 27 h and 1.5 m after 36 h. The research findings of this paper can provide scientific guidance for revealing the hydrological characteristics of slopes during rainfall and for the protection and reinforcement of slopes. [ABSTRACT FROM AUTHOR]

Dry–wet cycles can cause significant deterioration of compacted loess and thus affect the safety of fill slopes. The discrete element method (DEM) can take into account the non-homogeneous, discontinuous, and anisotropic nature of the geotechnical medium, which is more capable of reflecting the mechanism and process of instability in slope stability analysis. Therefore, this paper proposes to use the DEM to analyze the stability of compacted loess slopes under dry–wet cycles. Firstly, to solve the complex calibration problem between macro and mesoscopic parameters in DEM models, an efficient parameter optimization method was proposed by introducing the chaotic particle swarm optimization with sigmoid-based acceleration coefficients algorithm (CPSOS). Secondly, during the parameter calibration, a new indicator, the bonding ratio (BR), was proposed to characterize the development of pores and cracks in compacted loess during dry–wet cycles, to reflect the impact of dry–wet action on the degradation of bonding between loess aggregates. Finally, according to the results of parameter calibration, the stability analysis model of compacted loess slope under dry–wet cycling was established. The results show that the proposed optimization calibration method can accurately reflect the trend of the stress–strain curve and strength of the actual test results under dry–wet cycles, and the BR also reflects the degradation effect of dry–wet cycles on compacted loess. The slope stability analysis shows that the DEM reflects the negative effect of dry–wet cycles on the safety factor of compacted loess slopes, as well as the trend of gradual stabilization with dry–wet cycles. The comparison with the finite element analysis results verified the accuracy of the discrete element slope stability analysis. [ABSTRACT FROM AUTHOR]

Due to the frequent occurrence of defects of slope protection facilities on existing lines causing the potential major geological hazards (e.g., landslides), it is necessary to promote the inspection and detection efficiency of various defects of slope protection facilities for carrying out early warning and evaluation, as well as, putting forward relevant control measures for slope disasters. Based on the case studies of hundreds of protective facilities on the existing railway line, the typical defect types, characteristics and specific causes of retaining wall, slope protection, anti-slide pile and anchorage engineering structure are firstly determined. Subsequently, a new comprehensive method combining unmanned air vehicle (UAV) and intelligent detection of portable radar (IDPR) are proposed. Among of them, UAV can effective and efficient identify the defect situations of slope protection facilities, and the water accumulation and cracks of retaining wall through performing a periodic inspection of the surrounding environment of protective facilities. In addition, IDPR can detect the filling situations behind the protective facilities to prevent the collapse danger. Through comparison with the drilling core results of tested areas, it is found that the detection results of the IDPR are more reliable and accurate, which is worthy of popularization and application in the field. [ABSTRACT FROM AUTHOR]

This study established a numerical model that considers elevation conditions and slope shape factors by the modified Sadovsky formula to analyze the vibration attenuation law of open-pit slopes under blasting vibration conditions. The blasting excavation of a slope in a certain open-pit mine in Yunfu, Guangdong, is selected as an example. Using a numerical model that considers elevation conditions and slope shape factors by the modified Sadovsky formula, a triangular pulse load was utilized to approximate the time-history characteristics of explosion vibration with FLAC[sup 3D] software. The simulation results showed the radiation range of the blasting vibration seismic wave. By comparison with field monitoring data, the numerical model that considers the slope shape factor had a relative error of ~10%, while the numerical model that disregards the slope shape factor had a relative error of ~15%. The relative accuracy of the calculation results of the new numerical model is higher and closer to the actual attenuation law of blasting particle vibration speed, providing more reliable results for slope stability assessment. The peak particle velocities obtained from the numerical simulation results were generally higher than the field monitoring data. These discrepancies might be attributed to the use of simplified models that disregard the discontinuous structural planes within the rock mass. This study provides an important reference for the stability assessment of open-pit slopes under blasting vibration conditions, offering guidance for improving slope stability assessment and related engineering practices. [ABSTRACT FROM AUTHOR]

This paper proposes an improved discretization‐based kinematic approach (DKA) with an efficient and robust algorithm to investigate slope stability in nonuniform soils. In an effort to ensure rigorous upper‐bound solutions which may be not satisfied by the initial DKA based on a forward difference method (DKA‐FD), a central and backward difference “point‐to‐point” method (DKA‐CD and DKA‐BD) is proposed to generate discretized points to form a velocity discontinuity surface. Varying (including constant) soil frictional angles along depth are discussed, which can be readily considered in the improved DKA‐CD. Work rate calculations are performed to derive upper‐bound formulations of slope stability number, and critical failure surface is correspondingly obtained at limit state. The comparison with forward and backward difference methods clearly reveals that the improved DKA‐CD could significantly reduce the mesh‐dependency issue and enhance efficacy of slope stability analyses in nonuniform soils. [ABSTRACT FROM AUTHOR]

Rocky coastlines are characterised by steep cliffs, which frequently experience a variety of natural processes that often exhibit intricate interdependencies, such as rainfall, ice and water run-off, and marine actions. The advent of high temporal and spatial resolution data, that can be acquired through remote sensing and geomatics techniques, has facilitated the safe exploration of otherwise inaccessible areas. The datasets that can be gathered from these techniques, typically combined with data from fieldwork, can subsequently undergo analyses employing/applying machine learning algorithms and/or numerical modeling, in order to identify/discern the predominant influencing factors affecting cliff top erosion. This study focuses on a specific case situated at the Conero promontory of the Adriatic Sea in the Marche region. The research methodology entails several steps. Initially, the morphological, geological and geomechanical characteristics of the areas were determined through unmanned aerial vehicle (UAV) and conventional geological/geomechanical surveys. Subsequently, cliff top retreat was determined within a GIS environment by comparing orthophotos taken in 1978 and 2022 using the DSAS tool (Digital Shoreline Analysis System), highlighting cliff top retreat up to 50 m in some sectors. Further analysis was conducted via the use of two Machine Learning (ML) algorithms, namely Random Forest (RF) and eXtreme Gradient Boosting (XGB). The Mean Decrease in Impurity (MDI) methodology was employed to assess the significance of each factor. Both algorithms yielded congruent results, emphasising that cliff top erosion rates are primarily influenced by slope height. Finally, a validation of the ML algorithm results was conducted using 2D Limit Equilibrium Method (LEM) codes. Ten sections extracted from the sector experiencing the most substantial cliff top retreat, as identified by DSAS, were utilised for 2D LEM analysis. Factor of Safety (FS) values were identified and compared with the cliff height of each section. The results from the 2D LEM analyses corroborated the outputs of the ML algorithms, showing a strong correlation between the slope instability and slope height (R2 of 0.84), with FS decreasing with slope height. [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]

The three-dimensional (3D) stability problem of triple-step slopes is important due to their unique profiles under natural rainfall conditions. In this paper, an innovative approach was proposed for rapidly evaluating the stability of triple-step slopes, which considers the effects of diverse hydraulic hysteresis paths caused by rainfall and drought alternation. Considering diverse hydraulic hysteresis paths, a 3D upper-bound analysis (UBA) mechanical model was developed. On this basis, a new analytical solution for the stability number (N S) of 3D slopes under the influence of hydraulic hysteresis was derived through the work and energy equation. The comparisons showed that the new analytical solution and proposed method are correct. Then, ranges of the controlling parameters of triple-step slopes were designed for practical use in slope engineering. Comprehensive discussions were presented, considering four distinct hydraulic hysteresis cases within the context of two typical scenarios involving silty and sandy soils. The results could provide a reference for the design and construction of triple-step slopes where rainy and drought conditions frequently alternate. [ABSTRACT FROM AUTHOR]

Currently, studies on Xinjiang desert water conveyance channels primarily focus on the selection of construction technologies, with the effects of bank slope reinforcement and the impact of internal and external factors on slope stability remaining unclear. This study utilizes finite element method to analyze the safety coefficient, overall displacement, and equivalent plastic zone of aeolian soil bank slopes before and after reinforcement during three distinct phases: the completion phase, the water transfer phase, and the water level plunge phase. Orthogonal tests were used to assess the trend and weighting of the influence of factors on bank slopes inside and outside the channel using the introduction of corrected range and Spearman correlation analysis. The findings indicate that the safety coefficient for the bank slopes of the desert channel both before and after reinforcement exceeds 1.30 during all phases. Post-reinforcement, the overall displacement and equivalent plastic zone are controlled compared to the pre-reinforced state. Both sensitivity analyses yielded that the factors affecting the weighting of bank slopes were, in descending order, aeolian soil cohesion > slope angle > angle of internal friction > slope height > unit-weight > thickness of concrete lining > height of the water level in the channel > rate of water level plunge; where aeolian soil cohesion, slope angle, angle of internal friction and thickness of concrete lining favoured the stability of the bank slopes, while others were unfavourable to the stability of the bank slopes. This study aims to provide a reference for the construction of desert water supply projects. [ABSTRACT FROM AUTHOR]