This study evaluates dykes stability of bauxite residue storage facility using limit equilibrium (LEM) and finite element methods (FEM), considering diverse construction phases. In LEM, steady state seepage is simulated using piezometric line while factor of safety (FOS) is determined by Morgenstern-Price method using SLOPE/W. In FEM, actual loading rates and time dependent seepage is modelled by coupled stress-pore water pressure analysis in SIGMA/W and dyke stability is assessed by stress analysis in SLOPE/W, referencing SIGMA/W analysis as a baseline model. Both the analysis incorporated suction and volumetric water content functions to determine FOS. FEM predicted pore pressures are validated against in-situ piezometer data. The results highlight that coupled hydro-mechanical analysis offers accurate stability assessment by integrating stress-strain behaviour, pore pressure changes, seepage paths, and dyke displacements with time. It is found that inclusion of unsaturated parameters in Mohr-Coulomb model improved the reliability in FOS predictions.
Extreme rainfall causes the collapse of rammed earth city walls. Understanding the depth of rainwater infiltration and the distribution of internal moisture content is crucial for analyzing the impact of rainfall on the safety and stability of these walls. This study focuses on the rammed earth city wall at the Mall site in Zhengzhou. Based on Richards' equation, the water motion equation of rammed earth wall is deduced and established. The change of moisture content of rammed earth wall and the development of wetting front under rainfall condition are studied. The stability of the rammed earth city wall under rainfall infiltration is analyzed by finite element methods. The results show that the water motion equation can effectively describe the moisture distribution inside the rammed earth city wall during rainfall. As the rainfall continues, the wetting front deepens, and the depth of the saturated zone increases. Just below the wetting front, the moisture content decreases rapidly and eventually returns to its initial value. the water motion equation provides a theoretical basis for analyzing water-related damage in rammed earth walls. Factors such as the initial soil moisture content, rainfall duration, and rainfall intensity significantly influence the distribution of the wetting front and moisture content. The saturation of the upper soil layers reduces the shear strength of the shallow soil, leading to a decrease in the safety factor, which can result in shallow landslides and collapse of the rammed earth wall. The research results can provide theoretical support for the analysis of water infiltration law of rammed earth city walls under rainfall conditions, and provide reference for revealing the instability mechanism of rammed earth city walls induced by rainfall. (c) 2025 Elsevier Masson SAS. All rights are reserved, including those for text and data mining, AI training, and similar technologies.
Stability analysis of undrained anisotropic slopes has been made by a semi-analytical approach. The variational calculus is employed to find the critical sliding surface and the extremized resistance functional for general undrained anisotropic materials in seismic condition. A complete set of formulation with the solution is presented. In this approach, no failure surface is assumed and it is obtained throughout the solution procedure. The semi-analytical solution highly increases the efficiency of the computational effort and the accuracy of the results. The stability factor is reported for a series of anisotropic slopes in undrained condition subject to a range of pseudo-static earthquake accelerations. Finally, the results are interpreted and discussed by AI to make a comparison between a manual and an AI-assisted interpretations.
This paper employed PFC3D and FLAC3D to conduct a three-dimensional discrete-continuous dual-scale coupled simulation and stability analysis of cohesive soil slope through discrete-continuous coupled algorithm and the gravity increase method. In the discrete element model zone, the progressive failure process of cohesive soil slope was studied by setting particles with different displacements to different colours, the evolutions of porosity and coordination number in the shear, sliding and stability zones of slope were analysed by arranging measurement spheres, and the variation law of particle position was obtained by the vertical layering of the soil. In the continuous model zone of coupled slope model, the horizontal and vertical stresses were verified with those of a pure FLAC3D model of slope. Furthermore, a comparative instability analysis of cohesive soil slope and gravelly soil slope was also performed. The safety factor for the cohesive soil slope in this work was determined to be 1.7 according to the mesoscopic fabric evolution of slope particles and the gravity increase method. The work in this paper broadens the application scope of the dual-scale coupled algorithm, highlights the differences in the mesoscopic instability mechanism between cohesive soil slop and gravelly soil slop, and provides new theoretical support for slope design and risk assessment in engineering practice.
The cracking and strength deterioration of expansive soil resulting from the wetting-drying cycle caused by the process of rainfall evaporation is a crucial factor in the initiation of slope instability. Understanding the impact of cracking development in expansive soil slopes on the infiltration process, and integrating it with the soil's strength deterioration for stability analysis, holds the key to addressing this issue. This study presents a stability calculation model for expansive soil slopes during the wetting-drying cycle, derived from the improved Richards' seepage model. The research findings reveal that the stratified infiltration model, which considers cracks, demonstrates better accuracy in reflecting the rainfall infiltration process compared to the traditional GA infiltration model. The case analysis confirms the significant influence of expansiveness on the stability of expansive soil slopes. Moreover, the stability analysis model derived from the stratified infiltration model exhibits a high level of agreement with the numerical simulation.
This article presents a micro-structure tensor enhanced elasto-plastic finite element (FE) method to address strength anisotropy in three-dimensional (3D) soil slope stability analysis. The gravity increase method (GIM) is employed to analyze the stability of 3D anisotropic soil slopes. The accuracy of the proposed method is first verified against the data in the literature. We then simulate the 3D soil slope with a straight slope surface and the convex and concave slope surfaces with a 90 degrees turning corner to study the 3D effect on slope stability and the failure mechanism under anisotropy conditions. Based on our numerical results, the end effect significantly impacts the failure mechanism and safety factor. Anisotropy degree notably affects the safety factor, with higher degrees leading to deeper landslides. For concave slopes, they can be approximated by straight slopes with suitable boundary conditions to assess their stability. Furthermore, a case study of the Saint-Alban test embankment A in Quebec, Canada, is provided to demonstrate the applicability of the proposed FE model. (c) 2025 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/ 4.0/).
The resilience and performance of quay walls during devastating events such as tsunamis and earthquake are critical for coastal infrastructure. Conventional design standards mostly address vertical or inclined quay walls, neglecting the potential benefits of more complex geometry, such as bilinear backface. This study presents a seismic design and stability analysis of quay walls with a bilinear backface under the combined action of tsunamis and earthquake. The study findings reveal a significant reduction in safety factors in terms of sliding and overturning when quay walls are simultaneously exposed to tsunami and earthquake forces. The study also proposes a bilinear wall geometry, considering key factors such as tsunami wave height, water depth, submergence height, excess pore pressure ratio, and wall inclination. This study aims to enhance the design and construction of quay walls with a bilinear backface, thereby improving the safety of coastal structures and communities against these rare but devastating events.
Global warming accelerates permafrost degradation, compromising the reliability of critical infrastructure relied upon by over five million people daily. Additionally, permafrost thaw releases substantial methane emissions due to the thawing of swamps, further amplifying global warming and climate change and thus posing a significant threat to more than eight billion people worldwide. To mitigate this growing risk, policymakers and stakeholders need accurate predictions of permafrost thaw progression. Comprehensive physics-based permafrost models often require complex, location-specific fine-tuning, making them impractical for widespread use. Although simpler models with fewer input parameters offer convenience, they generally lack accuracy. Purely data-driven models also face limitations due to the spatial and temporal sparsity of observational data. This work develops a physics-informed machine learning framework to predict permafrost thaw rates. By integrating a physics-based model into machine learning, the framework significantly enhances the feature set, enabling models to train on higher-quality data. This approach improves permafrost thaw rate predictions, supporting more reliable decision-making for construction and infrastructure maintenance in permafrost-vulnerable regions, with a forecast horizon spanning several decades.
Reservoir landslides represent a significant geological hazard that jeopardizes the safety of reservoirs. Deformation monitoring and numerical simulation are essential methodologies for elucidating the evolutionary patterns of landslides. Nonetheless, the existing approaches exhibit limitations in revealing the potential deformation mechanism. Consequently, this study proposes an innovative strategy that incorporates interferometric synthetic aperture radar (InSAR) deformation characteristics alongside fluid-solid coupling stress analysis to investigate the deformation, focusing on the Shuizhuyuan landslide within the Three Gorges Reservoir area as a case study. Using temporary coherence point InSAR technology, significant motion units were identified, with a maximum deformation rate of -60 mm/yr. The complete deformation time series reveals three independent components of landslide movement and their trigger factors geometrically. Subsequently, the saturation permeability coefficient of the sliding mass in the seepage analysis is modified with the assistance of InSAR deformation. Then, we coupled the seepage analysis results to FLAC3D model for stress and strain analysis, and determined the seepage-induced progressive failure mechanism and the deformation mode of the Shuizhuyuan landslide, driven by reservoir water-level (RWL) drop. The numerical simulation results aid in interpreting the deformation mechanism of different spatial and temporal patterns of landslides from three aspects: hydrodynamic pressure from rainfall infiltration, groundwater hysteresis caused by RWL drop, and seepage forces from RWL rise. Furthermore, our findings reveal that the dynamic factor of safety (FOS) of landslide during the InSAR observation period is highly consistent with the periodic fluctuations of the RWL. However, there is also a small trend of overall decline in FOS that cannot be ignored.
Transient seepage triggered by rainfall and water level changes has a significant impact on embankment stability. To investigate the effects of rainfall and water level changes on the seepage field of embankments, numerical comparative experiments were conducted based on the Shu River embankment project. The influence of key factors such as rainfall, water level rise and fall rate, and rainfall-coupled water level rise and fall on the internal seepage field of the embankment was analyzed, and the main factors affecting the stability of the embankment slope were identified. The relationship among permeability coefficient, lag rate of the phreatic line, and embankment slope stability factor is explored, and fitting equations are developed. The results show that rainfall infiltration increases the pore water pressure of the soil, leading to a decrease in the effective stress of the soil and a decrease in the slope stability factor. The stability factor of the embankment slope is positively correlated with the rise and fall of the water level, and the faster the rate of rise and fall, the higher the rate of change in pore water pressure. The stability factor of the embankment slope showed a trend of decreasing and then increasing with the decrease in water level, and when the water level had decreased by 70%, the lag rate of the phreatic line was the largest, and the stability factor of the embankment slope was the lowest. The established equations for fitting the stability factor of the embankment slope to the lag rate of the phreatic line can be used as a reference for the safety assessment of similar embankment projects.