Unit Weight Of Soil Research Articles

A modified solution for evaluating the sliding direction and stability of 3D slopes

In this paper, we present an improved and efficient analytical solution for evaluating the stability of 3D slopes based on the minimum potential energy method. The equilibrium equation of the landslide is employed to determine the shear stress on the failure surface, and a new formulation for shear potential energy is introduced. The vector-combined direction of the force acting on the landslide is considered equivalent to the sliding direction (SD). Two classic examples are reanalyzed to validate the accuracy and performance of the proposed method. The analysis demonstrates that the obtained results align well with reference solutions and tend to be conservative in engineering applications. Parameter investigations are conducted to explore the influences of SD, shear strength parameters, slope angle, and soil unit weight on the safety factor (SF) of 3D slopes. The findings indicate that a larger SD corresponds to a less stable slope. Finally, the effects of optimization parameters, landslide volume, and surcharge on the location of the failure surface, SF, and SD are also examined. The developed analytical approach offers a novel and straightforward solution with sufficient accuracy and eliminates the need for iteration in determining the SF, making it a valuable complementary method for assessing the stability of 3D slopes.

An Analytical Insight Into Stability Analysis of Unsaturated Multi‐Layered Slopes Subjected to Rainfall Infiltration

ABSTRACTSlopes in nature usually present layered characteristics, and its stability is susceptible to rainfall events. Considering that current analytical solutions are only suited to simulate the rainfall infiltration of double‐layered infinite unsaturated slopes, an analytical procedure is hence proposed in this study to tackle the consideration of multiple layers. The variable separation method and transfer matrix method are combined to derive the analytical solution of pore water pressure (PWP) for simulating rainfall infiltration in layered infinite unsaturated slopes. After having validated the proposed model and analytical solutions by comparing with existing literature and numerical simulation, the closed‐form solution of PWP is incorporated into the limit equilibrium for assessing slope stability. A three‐layer slope is selected as an example for further discussion. PWP distribution and factor of safety are calculated, considering the effects of saturated hydraulic conductivity and thickness of the upper layer, intensity of antecedent and subsequent rainfall, and varied soil unit weight along the depth. The slope stability subjected to rainfall effects is consistent with the variation of PWP. The proposed analytical solutions provide a simple and practical avenue for computing PWP distribution and evaluating the stability of multi‐layered slopes under rainfall conditions, which can also serve as a benchmark for numerical solutions.

Evolution of relative density and shear wave velocity in non-compacted embankment layers: Geological long-term monitoring

This study proposes a novel method for assessing the evolution of relative density and shear wave velocity that vary with depth and effective stress in non-compacted embankment layers. Embedded soil stiffness measurement devices were used to monitor the shear waves at each stage of filling at the test site, and comprehensive laboratory compaction tests were conducted using a floating ring oedometer cell to reproduce real field conditions with minimal friction. Assuming a constant soil unit weight γ with 7% water content, the effective stress σ’ is proportional to depth z (i.e., σ’ = γ·z). Field test results were compared with the shear wave velocity relationships determined in laboratory tests for four samples of differing relative density (30%, 50%, 70%, and 90%), indicating that the relative density at the bottom of the embankment varied between 15% and 48%. However, the constant soil unit weight applied in this study can underestimate the relative density of the embankment, causing a prediction error if the self-weight compaction of the embankment is not minute. Therefore, this study provides guidelines based on a physics-inspired and data-based approach and anticipates the relative density and shear wave velocity analyzed in the context of depth in non-compacted embankment layers. The physics-based data analyses suggested in this study can be used in first-order estimations to assess the relative density and shear wave velocity evolution in non-compacted embankment layers.

Soil erodibility results of revegetation using bitti plant at various ages reclamation of quarry a lime stone mine at Pt Semen Tonasa, Pangkep District, South Sulawesi

Background: Limestone mine reclamation carried out by PT Semen Tonasa is carried out periodically as an effort to restore land conditions in a sustainable manner. The reclamation was carried out in the form of revegetation using endemic plants, namely the bitti plant (Vitex cofassus R.) which grows a lot in the southern part of Sulawesi. This study aims to determine the erodibility of the soil in limestone mine reclamation land planted with bitti plants. Methods: The method used is the survey method by determining the location of soil samples using the purposive sampling method based on the reclamation age planted with bitti plants in 2019, 2015 and 2010 and determining the erodibility value using the formula according to Wischmerier and Smith (1978). Parameters used included soil texture, soil structure, organic matter, soil permeability, soil pH, and soil unit weight. Findings: The results of this study indicate that the erodibility of the soil in the limestone mine reclamation land planted with bitti plants is classified as high due to the high dust content which is influenced by the parent material. The results of this study indicate that the erodibility value of the land reclamation in 2019 was classified as moderately low to moderately high, the land reclamation in 2015 was classified as moderate to moderately high, and the land reclamation in 2010 was classified as moderate to high. Conclusion: The factor affecting the erodibility of the soil in the reclamation area is the M value (percentage of very fine silt and sand). Novelty/Originality of this Study: The novelty of this study lies in the examination of soil erodibility changes over different reclamation ages in a limestone mine using endemic bitti plants. This research highlights the unique relationship between reclamation age and soil properties, contributing valuable insights into effective land reclamation practices in tropical karst environments.

Reliability and sensitivity analyses of monopile supported offshore wind turbines based on probability density evolution method with pre-screening of controlling parameters

To reasonably investigate the influence of pile-soil interaction on the dynamic reliability of monopile supported offshore wind turbines (OWTs), a framework with high efficiency and good accuracy is proposed for reliability and sensitivity analyses of monopile supported OWTs. This proposed framework combines the grey relational analysis (GRA), the probability density evolution method (PDEM), and the interval mathematical analysis method (IM). Firstly, the GRA is applied to identify the main controlling parameters influencing the stochastic dynamic response of a monopile supported OWT, considering various factors such as pile elasticity modulus, soil internal friction angle and soil unit weight. Secondly, combining the probability density evolution theory, a complete sample probability set is established to obtain the dynamic reliability of the monopile supported OWT under wind and wave loads. Finally, the effect of each controlling parameter on the dynamic reliability of the monopile supported OWT is systematically analyzed by combining the IM and the change of probability measure. The proposed GRA-PDEM-IM-based framework for reliability analyses of monopile supported OWTs can effectively reduce the number of samples for probability density evolution calculations and provide reasonable and accurate reliability analyses results which can serve as a reference for design and construction of monopile supported OWTs.

How large is the collapsed area of ground collapse induced by tunnelling

ABSTRACT Ground collapse has frequently been reported in recent years, which poses a great threat to the safety of human beings and property. This study aims to determine the collapsing diameter and volume of tunnelling-induced ground collapse by analytical method. Firstly, assuming that the surface of collapsed block is sliding along a planar surface, and the sliding area is derived based on the limit equilibrium method. Then, the collapse volume is derived by combining with the equation of the collapse trajectory. Lastly, the proposed method is verified by a physical modelling test. The results show that (i) as the unit weight of soil, buried-depth and the radius of tunnel increase, the influencing diameter and collapse volume gradually increase; (ii) with the increase in the cohesion and friction angle of the soil, the influencing diameter and collapse volume gradually decrease. Dongquan Tunnel is taken as a case study, the influencing diameter of ground by using the proposed approach is compared with the one in practical engineering. This study provides a theoretical guideline to mark the collapse warning lines by the potential ground collapse area, which is induced by excavation of shallow-buried tunnels or underground structures.

A case study on soil slope landslide failure and parameter analysis of influencing factors for safety factor based on strength reduction method and orthogonal experimental design.

In civil engineering, stability analysis of slope is one of the main content of design. By using the finite element limit analysis software OptumG2, a landslide geological model is established to simulate the failure process of the landslide in Huadu District, Guangzhou City, China. The analysis focused on the deformation and failure characteristics, as well as the mechanical mechanism of landslide; the landslide mode of homogeneous soil is circular sliding. Additionally, investigating the influencing factors affecting slope stability is crucial in engineering implementation; in which the five influencing factors are considered as follow: slope height, slope gradient, soil cohesion, soil internal friction angle, and soil unit weight, respectively. A stability calculation model for a soil slope is established under 25 working conditions based on strength reduction method and orthogonal experimental design, in which the relationship between the safety factor and slope height, slope gradient, soil cohesion, soil internal friction angle, and soil unit weight is obtained. As the slope height increases from 5m to 45m, the safety factor of soil slope gradually decreases from 2.21 to 0.94; As the slope gradient increases from 20° to 60°, the safety factor of soil slope decreases approximately linearly from 1.80 to 0.95; As the cohesion of soil increases from 10kpa to 30kpa, the safety factor of soil slope increases approximately linearly from 1.04 to 1.60; As the internal friction angle of soil increases from 10° to 30°, the safety factor of soil slope increases approximately linearly from 1.00 to 1.81; As the unit weight of soil increases from 13kN/m3 to 21kN/m3, the safety factor of soil slope decreases approximately linearly from 1.50 to 1.21. The influencing factors affecting the safety factor of soil slope in descending order are slope height, slope angle, soil internal friction angle, soil cohesion, and soil unit weight. The research has reference significance for studying the stability and failure laws of soil slopes and conducting landslide control on soil slopes.

Slope failure lines analysis to determine landslide potential based on standard penetration test method

Landslide events cause road access to be cut off, such as in the Payung area of Batu City, which connects Malang and Kediri. Analysis and evaluation of landslide disasters need to be carried out in this area to anticipate the next landslides and reduce economic losses. This study aims to determine landslide potential in the Payung Area, Batu City, using the SPT method. The test is carried out at 2 points of the slope on the provincial roads and the slope above the road so that the two measurement points can be correlated. The data needed to analyze slope stability include the internal shear angle, cohesion, and soil unit weight; analysis and modeling of slope stability using Geostudio SLOPE/W software. The results of the slope stability analysis at point 1 show that the average failure line is at a depth of 6.00 m with the smallest Safety Factor (SF) value of 0.710 in scenario 2. While the slope at point 2, the failure line is at a depth of 1.50 m with the smallest FK value of 0.840 in scenario 2. Significant changes in the N-SPT value indicate differences in soil mechanical properties, such as shear angle and cohesion that affect the stability of the slope and cause landslides.

Comparing shallow landslide susceptibility maps in Northeastern Türkiye (Beşikdüzü, Trabzon): a multivariate statistical, machine learning, and physical data-based analysis

This study endeavors to assess and compare the efficacy of various modeling approaches, including statistical, machine learning, and physical-based models, in the creation of shallow landslide susceptibility maps within the Besikduzu district of Trabzon province, situated in the Black Sea Region of Türkiye. The landslide inventory data, spanning from 2000 to 2018, was acquired through meticulous field surveys and analysis of Google Earth satellite imagery. Key topographic and geologic input parameters, such as slope, aspect, topographic wetness index, stream power index, plan and profile curvature, and geologic units, were extracted from a high-resolution 10 m spatial DEM (Digital Elevation Model) and a 1:25,000 scaled digital geology map, respectively. Additionally, soil unit weight and shear strength parameters, critical for the physical-based model, were determined through field samples. To evaluate landslide susceptibility, logistic regression, random forest, and Shalstab were employed as the chosen methods. The accuracy of susceptibility maps generated by each method was assessed using the area under the curve method, yielding impressive values of 0.99 for the random forest model, 0.97 for the logistic regression model, and 0.93 for the Shalstab model. These results underscore the robust performance of all three methods, suggesting their applicability for generating shallow landslide susceptibility maps not only in the Black Sea Region but also in analogous areas with similar geological characteristics.

Data-Driven Prediction of Maximum Settlement in Pipe Piles under Seismic Loads

The structural stability of pipe pile foundations under seismic loading stands as a critical concern, demanding an accurate assessment of the maximum settlement. Traditionally, this task has been addressed through complex numerical modeling, accounting for the complicated interaction between soil and pile structures. Although significant progress has been made in machine learning, there remains a critical demand for data-driven models that can predict these parameters without depending on numerical simulations. This study aims to bridge the disparity between conventional analytical approaches and modern data-driven methodologies, with the objective of improving the precision and efficiency of settlement predictions. The results carry substantial implications for the marine engineering field, providing valuable perspectives to optimize the design and performance of pipe pile foundations in marine environments. This approach notably reduces the dependence on numerical simulations, enhancing the efficiency and accuracy of the prediction process. Thus, this study integrates Random Forest (RF) models to estimate the maximum pile settlement under seismic loading conditions, significantly supporting the reliability of the previously proposed methodology. The models presented in this research are established using seven key input variables, including the corrected SPT test blow count (N1)60, pile length (L), soil Young’s modulus (E), soil relative density (Dr), friction angle (ϕ), soil unit weight (γ), and peak ground acceleration (PGA). The findings of this study confirm the high precision and generalizability of the developed data-driven RF approach for seismic settlement prediction compared to traditional simulation methods, establishing it as an efficient and viable alternative.

Integrating Root Morphology Based on Whole-Pullout Test of Model Roots: A Case Study

To investigate the sensitivity and significance of different morphological characteristics of plant root systems on vertical pullout resistance, this study considered four main influencing factors: the number of lateral roots, taproot length, the branching angle of the lateral root, and the unit weight of the soil around the root. PC plastic model roots were employed to conduct a vertical pullout orthogonal experiment. A comprehensive μX theoretical analysis method based on the whole root system pullout test was applied for a stress analysis on root segments. Based on the results, the factors affected the vertical pullout resistance of plant root systems in the order of number of lateral roots > taproot length > unit weight of soil around the root > branching angle of the lateral root. When the number of lateral roots increased from 2 to 3, the vertical pullout resistance increased by 64%. Also, when the taproot length increased from 50 to 60 cm, the vertical pullout resistance increased by up to 46%. Furthermore, the unit weight of soil around the roots had a positive linear correlation with vertical pullout resistance. Based on the results, the number of lateral roots and the taproot length were the primary factors affecting the magnitude of the root system’s vertical pullout resistance. When selecting plants for slope protection, plant types with a larger number of lateral roots and longer taproots should be considered as the two most significant factors for achieving a better slope protection methodology.

Bearing capacity factor for strip foundations on unsaturated clay

ABSTRACT The matric suction in unsaturated soil depends on the type of soil and various flux conditions i.e., infiltration, evaporation and no flow. The shear strength of unsaturated soil changes with change in matric suction leading to varying resistance of soil under various flow conditions. In this study, the bearing capacity of strip foundations resting over unsaturated clay considering variation of matric suction with depth for different surface flux conditions and position of water table, has been obtained using finite element lower bound limit analysis. Modified Mohr-Coulomb yield criteria based on unified effective stress approach has been employed to incorporate the contribution of matric suction stress to the failure condition. A non-dimensional bearing capacity factor was introduced to estimate the bearing capacity of strip foundations and presented as a function of different influencing parameters such as foundation width, water table depth, soil properties, various flow conditions and their flow rate, and surcharge pressure. The influence of variation of unit weight of soil in the unsaturated zone, air entry and pore size distribution parameters, residual degree of saturation of soil, specific gravity of soil solids, and foundation-soil interface roughness on the bearing capacity has also been examined and found to be insignificant.

Stability analysis of a vertical excavation reinforced with horizontal nails using three-dimensional finite elements limit analysis

Three-dimensional stability analysis of a vertical excavation, reinforced with grouted horizontal nails, has been carried out by using the three dimensional lower and upper bounds based finite elements limit analysis (FELA) using Optum G3. The nail along with the surrounding grouted cementitious material is assumed to behave as a single monolithic cylindrical block which was assumed to be either rigid or an elasto-plastic material following the Von-Mises yield criterion. The excavation is assumed to fail on account of either an interface shear slippage between nails and surrounding soil mass or on an account of axial tensile rupture of the composite nail material for a few typical cases as well. The soil unit weight has been varied to induce the ultimate shear failure of the soil nailed excavation. The unit weight of the soil mass at which the failure of the nailed wall occurs is termed as γcr. Two different types of boundary conditions along the base of the excavation have been considered. In the first case, the in-situ soil mass behind the excavation is extended below the base as well (Case 1) and in the second case, the excavation is assumed to simply lie on a hard stratum (Case 2). The results have been provided in the form of a non-dimensional stability number N=γcrHc as a function of soil friction angle φ, Sv/H, SH/H, d/H, L/H and m; where H refers to height of the wall, d is diameter of the grouted nail, Sv and SH imply centre to centre vertical and horizontal spacing of the nails, and m is the mobilization factor between grouted nails and adjoining soil mass. The results from the analysis have been found to compare well with the data reported in literature. All the results have been presented in the form of non-dimensional stability charts, which will be useful for design for any given values of height H and cohesion c. From the observed failure mechanisms, an analysis has also been carried out to determine the optimized lengths of nails. The optimized lengths of nails for both Cases 1 and 2 have been also provided. The type of failure mechanism, base or face failure, dictates the optimized lengths of the nails.

A particle-scale insight into the face stability of shallow EPB shield tunnels in dry cobble-rich soil

The aim of this paper is to provide a particle-scale insight into the face stability of shallow (C/D = 1.0; C = tunnel buried depth and D = tunnel diameter) earth pressure balanced (EPB) shield tunnels in cobble-rich soil, considering both the dynamic excavation process and particle size gradation. The work was performed by three dimensional discrete element method (DEM). Results show that particle size greatly influences the movement of cobble particles. The coarse particles serve as the skeleton of the ground and provide the stability. The erosion of fine particles has little influence on tunnel face stability, while the erosion of middle particles weakens tunnel face stability. The limit support pressure pf increases with increasing cutterhead rotating speed, and the normalized limit support pressure pf/γD (γ = soil unit weight, D = tunnel diameter) obtained in this paper is larger than existing researches. The abrupt increase of middle particles in the muck composition can be recognized as the forewarning information against face failure.

THE SOIL CARBON STOCK IN THE TOURISM AREA OF GILI TRAWANGAN

This study aims to determine the distribution of carbon stocks in various land uses and total carbon stocks in the tourism area of ​​Gili Trawangan. This research was conducted in the Gili Trawangan area, Physics and Soil Conservation Laboratory, and Soil Chemistry and Biology Laboratory, Faculty of Agriculture, University of Mataram, in June-October 2022. The method used in this study was a descriptive method with a survey technique. The descriptive method can start with data collection, analysis and interpretation. Carbon in the soil in this study was obtained from the results of C-organic laboratory analysis (Walcky and Black) supported by measurements of soil unit weight (BV), soil porosity and soil texture. Meanwhile, aboveground carbon stocks were obtained through direct sampling in the field by measuring tree biomass. The results showed that the total carbon stocks in various land uses have different carbon stocks. The mixed garden had the highest carbon stock of 840.27 ton.ha-1, forest land of 83.76 ton.ha-1, and shrubs of 15.76 ton.ha-1, and the lowest carbon stock was a settlement of 3.01 ton. ha-1. Overall, carbon stocks in the tourist area of ​​Gili Trawangan are 942.8 ton.ha-1.

The experimental procedures of sand and lime as base soil stabilization materials on the modified proctor values for flexible pavement construction

During road construction, one of the major challenges encountered is dealing with weak subgrade soil, specifically expansive soil that experiences volume changes due to variations in moisture content. Lime stabilization is a widely used method for improving post-construction stability, offering cost savings, and reducing environmental impact. This study reviews various methods for creating soil-lime mixtures, comparing testing methods. Effective soil stabilization leads to improved construction outcomes, cost reduction, and minimized environmental impact. Soil characteristics, including Maximum Dry Density (MDD) and Optimum Moisture Content (OMC) value, are important factors in determining suitability for construction. Therefore, this study focused on soil characterization, grain analysis, Atterberg limits, and modified compaction before and after lime as well as sand stabilization. This study also determined soil characteristics, grain gradation, Atterberg limit, and modified compaction, and also developed implementation methods and budget plans for stabilized earthworks. Subsequently, the tests included moisture content, density, specific gravity (Gs), sieve analysis, grain analysis with a hydrometer, Atterberg limits, and modified compaction. The tests were conducted with varying percentages of sand (20 %) and lime (5 %, 10 %, 15 %, and 20 % of soil dry weight). Original soil moisture content value (w) = 53.70 %, Wet soil unit weight (γ) = 1.69 gr/cm3, Gs = 2.69, The original soil is classified into A-2–7 as (silty gravel or clay and sand) according to AASHTO.•This method shows the effect of sand and lime as base stabilization materials.•This method examines the roles of modified proctor on the flexible pavement.•This study explores MDD and OMC for curing times of 1, 7, and 14 days.

Study on the destruction law of physical and shear properties of soil in mining disturbance

Underground mining activities can easily trigger surface subsidence and cause damage to surface soil. However, there is still a lack of studies on damaged soil, restricting ecological remediation in mining-induced subsidence regions to a certain degree. Focusing on the particular example of No. 4 Mine in Yili, Xinjiang, China, this study comprehensively combined field sampling, laboratory experiments, and data analysis to investigate the variation rules of basic physical properties and shear characteristics of soil samples. The latter had different subsidence degrees (0, 0–20, 20–40, and above 40 cm) and various depths (0– 10, 10–20, 20– 40, 40–60, and 60–80 cm). The experimental results show that: First, the natural density and dry unit weight of shallow soil in the serious-subsidence region were more significantly affected by mining-induced subsidence than the conditions in the deep layer, which also dropped with the increase in subsidence degree (with a mean drop rate of 7%). Second, serious subsidence could greatly counteract the positive effect of slight and moderate subsidence on the soil shear strength, with a drop rate of up to 30.7%. Third, compared with soil physical indices, mining-induced subsidence more easily affected shear strength indices. In particular, the soil samples taken from 0 to 10 cm depth in the slight subsidence area and 60–80 cm depth in the moderate subsidence area were most significantly affected by mining-induced subsidence, with PCA comprehensive scores of over 1.5. The present study can con-tribute to gaining in-depth knowledge of the damage characteristics of surface soil under mining-induced subsidence and provide a theoretical foundation for formulating reasonable coal mining strategies and ecological protection measures.

Underground storage tank blowout analysis: Stability prediction using an artificial neural network

Most geotechnical stability research is linked to “active” failures, in which soil instability occurs due to soil self-weight and external surcharge applications. In contrast, research on passive failure is not common, as it is predominately caused by external loads that act against the soil self-weight. An earlier active trapdoor stability investigation using the Terzaghi's three stability factor approach was shown to be a feasible method for evaluating cohesive-frictional soil stability. Therefore, this technical note aims to expand “active” trapdoor research to assess drained circular trapdoor passive stability (blowout condition) in cohesive-frictional soil under axisymmetric conditions. Using numerical finite element limit analysis (FELA) simulations, soil cohesion, surcharge, and soil unit weight effects are considered using three stability factors (Fc, Fs, and Fγ), which are all associated with the cover-depth ratio and soil internal friction angle. Both upper-bound (UB) and lower-bound (LB) results are presented in design charts and tables, and the large dataset is further studied using an artificial neural network (ANN) as a predictive model to produce accurate design equations. The proposed passive trapdoor problem under axisymmetric conditions is significant when considering soil blowout stability owing to faulty underground storage tanks or pipelines with high internal pressures.

A practical approach for soil unit weight estimation using artificial neural networks

The soil unit weight is a relevant geotechnical and geological parameter in interpreting field tests, estimating parameters, and developing designs. The most precise way to estimate the soil unit weight is through controlled laboratory tests, which require samples with undisturbed structures. However, such tests produce results specific to the extracted sample point and depth, making the abstraction difficult in large areas. Efforts in the literature rely on in situ penetration tests and mathematical equations to simplify estimating the parameter value for general scenarios. On the other hand, each sort of soil can have a characteristic behavior, reducing the precision of estimations and hindering the adoption of statistical-based models universally. We propose a practical approach supported by machine learning to predict the soil unit weight, which produces estimations with an R2 of 0.82. The methodology consists of three phases: (i) we perform a clustering analysis to understand if different soils have similarities that permit the generation of multiple models; (ii) we statistically examine soils parameters to identify relevant parameters and produce a regression model, and; (iii) we feed an ANN with in situ parameters to estimate the soil unit weight. We make publicly available a web application to estimate the soil unit weight.

Upper-bound optimized solution of unsaturated soil slope stability under steady and unsteady flows

The increasing frequency of extreme weather events is leading to a rise in unsaturated soil slope instability near the earth's surface year by year. Establishing the method for analyzing slope stability under complicated hydrological conditions is imperative. This study proposes an approach that combines finite element (FE) seepage analysis with upper-bound limit analysis to evaluate the stability of unsaturated soil slopes. Two kinematically failure mechanisms are constructed based on the spatial discretization technique via point by point including the rotational and rotational-translational combinational failure modes, which can adapt to the complex pore water pressure distribution and varying soil unit weight. Additionally, a novel optimized solution scheme that integrates dichotomy and meta-heuristic optimization approaches is adopted to determine the factor of safety (FoS) and critical slip surface of slopes. The effectiveness and practicality of this method are validated by comparing with the published examples of slope stability evaluation under horizontal and inclined water table. Moreover, the variation of failure mode during the rainfall infiltration is illustrated by a case study of the slope under heavy rainfall. The methodological framework presented in this study can provide a basis for evaluating the stability of saturated–unsaturated soil slopes with 2D seepage conditions.