Effects of anisotropy in correlation structure on reliability-based slope stability analysis of a landfill

2020 ◽  
pp. 0734242X2094636
Author(s):  
Mohammad Javad Mehdizadeh ◽  
Nader Shariatmadari ◽  
Mehran Karimpour-Fard
Keyword(s):  
Slope Stability ◽  
Safety Factor ◽  
Failure Probability ◽  
Random Variables ◽  
Unit Weight ◽  
Distribution Fitting ◽  
Correlation Lengths ◽  
Isotropic Structure ◽  
The Mean ◽  
Factor Data

In this study, a reliability-based analysis of slope stability in a landfill considering the spatial variability of shear strength (c and φ) and unit weight ( γ) of municipal solid waste was performed using the random finite difference method. The effect of the anisotropic correlation (AC) structure of random variables including c, φ, and γ on mean and coefficient of variation (CoV) of safety factor values was investigated using Monte Carlo simulation. Also, probability of failure was determined through probability distribution fitting to a series of safety factor data. The results showed that the AC of the random variables has a significant effect on the stochastic safety factor of landfill slope. In general, the mean of the stochastic safety factor decreases with increasing horizontal and vertical correlation lengths (CLs). Also, the CoV of the safety factor increased with increase in horizontal or vertical CLs or both. Moreover, it was found that failure probability increases with an increase in the horizontal and vertical CLs and assuming isotropic structure for the correlation of random variables leads to the underestimation of failure probability. Overall, the results indicate that assuming an AC structure results in different failure mechanisms in the landfill slope, which are different from the deterministic cases.

scholarly journals Application of Harmony Search Algorithm to Slope Stability Analysis

Land ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1250
Author(s):  
Sina Shaffiee Haghshenas ◽  
Sami Shaffiee Haghshenas ◽  
Zong Woo Geem ◽  
Tae-Hyung Kim ◽  
Reza Mikaeil ◽  
...  
Keyword(s):  
Stability Analysis ◽  
Slope Stability ◽  
Safety Factor ◽  
Search Algorithm ◽  
Limit Equilibrium ◽  
Harmony Search ◽  
Harmony Search Algorithm ◽  
Slope Stability Analysis ◽  
Unit Weight ◽  
Slope Safety

Slope stability analysis is undoubtedly one of the most complex problems in geotechnical engineering and its study plays a paramount role in mitigating the risk associated with the occurrence of a landslide. This problem is commonly tackled by using limit equilibrium methods or advanced numerical techniques to assess the slope safety factor or, sometimes, even the displacement field of the slope. In this study, as an alternative approach, an attempt to assess the stability condition of homogeneous slopes was made using a machine learning (ML) technique. Specifically, a meta-heuristic algorithm (Harmony Search (HS) algorithm) and K-means algorithm were employed to perform a clustering analysis by considering two different classes, depending on whether a slope was unstable or stable. To achieve the purpose of this study, a database made up of 19 case studies with 6 model inputs including unit weight, intercept cohesion, angle of shearing resistance, slope angle, slope height and pore pressure ratio and one output (i.e., the slope safety factor) was established. Referring to this database, 17 out of 19 slopes were categorized correctly. Moreover, the obtained results showed that, referring to the considered database, the intercept cohesion was the most significant parameter in defining the class of each slope, whereas the unit weight had the smallest influence. Finally, the obtained results showed that the Harmony Search algorithm is an efficient approach for training K-means algorithms.

Non-Probabilistic Reliability Research on Slope Stability Based on Interval Analysis

2013 ◽  
Vol 838-841 ◽  
pp. 835-839
Author(s):  
Xiao Chun Lu ◽  
Liang Gan
Keyword(s):  
Slope Stability ◽  
Reliability Analysis ◽  
Uniform Distribution ◽  
Safety Factor ◽  
Failure Probability ◽  
Interval Analysis ◽  
Evaluation System ◽  
Safety Evaluation ◽  
Structural Performance ◽  
Performance Function

In this paper, slope stability considering non-probabilistic reliability analysis based on interval analysis was discussed. We can get safety factor, safety factor interval, non-probabilistic reliability by slope stability computation based on interval analysis. Based on the hypothesis that interval variable of structural performance function numerical value obeys uniform distribution, failure probability based on interval analysis was put forward. These form plural evaluation system about slope stability; it perfects safety evaluation for slope stability.

scholarly journals Groundwater Fluctuation Simulation in Pagelaran Landslide, Cianjur, Indonesia

2020 ◽  
Vol 11 (1) ◽  
pp. 41
Author(s):  
Twin Hosea Widodo Kristyanto
Keyword(s):  
Slope Stability ◽  
Safety Factor ◽  
Groundwater Level ◽  
Slip Surface ◽  
Unit Weight ◽  
Undisturbed Soil ◽  
Actual Position ◽  
Groundwater Fluctuation ◽  
Artesian Wells ◽  
The Stability

Pagelaran is one of area in Southern Part of Cianjur. This area has high susceptibility of landslide. One of landslide in Pagelaran, which happened on December 2014, has destroyed 13 houses and damaged vital road along 200 m. A year later, it started to conduct observation regarding the slope. The research aimed to know the role of groundwater level fluctuation in Pagelaran Landslide. The geometry of slope and its slip surface were determined using Electrical Resistivity Tomography. The actual groundwater level was determined by measuring it from surrounding artesian wells. Parameters angle of friction, cohesion, and unit weight were obtained from laboratory tests toward undisturbed soil samples. These data were used for analyzing the actual slope stability condition. Then it was conducted the simulation of slope stability in accordance with fluctuations of groundwater level. The simulation was done by raising the groundwater level with range of 0.5 m. The results showed that the actual slope stability was in critical condition with the value of safety factor 1.044. It also showed that slope stability waned as rising of groundwater level. The value of safety factor was reduced by an average of 0.034 in each 0.5 m up of groundwater level until it became failure (FS<1) when the groundwater level was 0.95 m above the actual position. Therefore, it can be concluded that the position of groundwater level played a role toward the stability of slope in Pagelaran. The rising 0.5 m of groundwater level position will reduce the slope safety factor by 0.034. The slope will become failure if the position of groundwater level rises by 0.95 meter from the actual position. To prevent the rising of groundwater level in rainy season, which can trigger landslide, it can be attached pipes along the slope body to flow the groundwater through them.

scholarly journals Analysis of Slope Stability with Imprecise Soil Properties Using Uncertain Sets

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Xuejun Zhou ◽  
Jie Li ◽  
Zhibing Liu ◽  
Yi Tang
Keyword(s):  
Slope Stability ◽  
Soil Properties ◽  
Safety Factor ◽  
Unit Weight ◽  
Membership Functions ◽  
Stability Of Slopes ◽  
Operational Laws ◽  
Layered Slope ◽  
The Stability ◽  
Parameter Values

There are many uncertainties with respect to the assessment of slope stability, and those associated with soil properties should be given particular attention. The uncertainty theory provides an alternative to treat these uncertainties using parochial cognitive sources. A novel methodology is proposed to evaluate the stability of slopes based on an uncertain set. The soil properties involved in the deterministic methods, i.e., shear strength parameters and unit weight, are expressed as uncertain sets, and their membership functions can be assumed to be triangular or trapezoidal for a homogeneous or two-layered slope, respectively. The parameter values of membership functions are designed according to the means and variations of the soil properties, and then the expected safety factor can be calculated through the operational laws. Two numerical examples including a homogeneous slope and a two-layered slope illustrate the suitability of the proposed methodology. The relationship between the variation in the safety factor and the changes in the soil properties is investigated; moreover, the determination of the parameter values of membership is also discussed.

The Sensitivity and Reliability Analysis of Slope Stability Based on Strength Reduction FEM

2013 ◽  
Vol 353-356 ◽  
pp. 491-494
Author(s):  
Ying Xiang Wu ◽  
Qiang Liu ◽  
Yu Jun Cang
Keyword(s):  
Sensitivity Analysis ◽  
Slope Stability ◽  
Reliability Analysis ◽  
Safety Factor ◽  
Failure Probability ◽  
Failure Surface ◽  
Strength Reduction ◽  
New Method ◽  
Mechanical Parameters ◽  
Calculation Process

A new method for reliability and sensitivity analysis of slope stability is proposed in this paper, which is based on strength reduction FEM. In this proposed method, the safety factor of slope can be calculated without assuming the shape and position of failure surface beforehand, and the randomness of physical and mechanical parameters of slope are considered in the calculation process. Meanwhile, the slopes failure probability is researched when the coefficients of variability change, and some useful conclusions are achieved.

The Effect of the Filling Caves on Loess Slope Stability in Irrigation

2013 ◽  
Vol 753-755 ◽  
pp. 648-652
Author(s):  
Yan Liang ◽  
Chao Liu ◽  
Tong Lu Li ◽  
Ping Li
Keyword(s):  
Shear Strength ◽  
Slope Stability ◽  
Failure Probability ◽  
Variation Coefficient ◽  
Unit Weight ◽  
Compacted Soil ◽  
Average Value ◽  
Loess Slope ◽  
The Stability

Landslides are serious geological disasters in loess areas. In order to study the effect of the filling caves in the edge of loess tableland on loess slope stability, the slope stability of sliding from the caves was calculated in irrigation when caves were filled with compacted soil, lime soil, lime-ash soil and non-filled. The results show when caves are filled with lime soil the slope stability is the highest. The effects of variability of the physical and mechanical property indexes of caver filler on loess slope stability were researched further. The results show that (1) the variation coefficients of unit weigh and the shear strength indexes of cave filler lime soil have small effect on the average value of safety reserve, but have big effect on the standard deviation of safety reserve, which explains that the design risks increase while the variation coefficient increasing. (2) with the increase of variation coefficients of unit weigh and the shear strength indexes of cave filler the failure probability increases. Especially when variation coefficient is bigger than 0.3, the failure probability of loess slope is very sensitive to variation coefficient. (3) the effect of correlation coefficient among unit weight and the shear strength indexes of cave filler on failure probability increases with the variation coefficient increasing. It is very important to guarantee filling project. Good quality of filling construction will decrease the variability of cave filler, heighten the stability of loess slope, and decrease the occurrence of loess disasters.

scholarly journals Análisis de Estabilidad Probabilístico del Talud de la Cantera Espinal – Juliaca

2018 ◽  
pp. 39-43
Keyword(s):  
Numerical Methods ◽  
Slope Stability ◽  
Safety Factor ◽  
Stress Reduction ◽  
Failure Probability ◽  
Probabilistic Analysis ◽  
Reduction Factor ◽  
Rock Slope Stability ◽  
Rocky Slope ◽  
Static Conditions

Análisis de Estabilidad Probabilístico del Talud de la Cantera Espinal – Juliaca Probabilistic Analysis of Slope Stability Espinal Quarry - Juliaca Fredy Alonso Valeriano Nina Facultad de Ingeniería de Minas, Universidad Nacional del Altiplano – Puno – Perú DOI: https://doi.org/10.33017/RevECIPeru2014.0006/ Resumen El presente estudio fue realizado en la cantera Espinal de la ciudad de Juliaca en el departamento de Puno, consiste en determinar los valores de seguridad que rigen la estabilidad o inestabilidad en un talud rocoso; factor de seguridad (FS) o reducción de la resistencia al corte (SRF) y la probabilidad de falla (PF), para lo cual se han utilizado los métodos generales de análisis de estabilidad de taludes en roca; Análisis cinemático y  métodos numéricos. Se realizó análisis probabilísticos por el método de estimación de puntos para mayor confiabilidad de los resultados de análisis con métodos numéricos. Teniendo como resultados en el análisis cinemático una probabilidad de plano de deslizamiento por volteo directo de 44.41%, los valores de seguridad promedio dado por los análisis probabilísticos con métodos numéricos en SRF son; para condiciones estáticas FS o SRF 2.27 y PF 0.0% y para condiciones seudoestáticas FS o SRF 1.21 y PF 2.98%. Por lo cual concluimos que el talud se encuentra estable en condiciones estáticas y seudoestáticas, tomando en consideración el resultado del análisis cinemático realizado se han observado grietas de tracción en la cresta del talud que fallaran por volteo directo dependiendo a la intensidad de los factores desencadenantes. Descriptores: Macizo rocosos, análisis probabilístico, factor de seguridad (FS), reducción de la resistencia al corte (SRF), probabilidad de falla (PF). Abstract This study was carried out in the Espinal highway of Juliaca city in the state of Puno, which consists in to determinate the safety values that controls the stability or instability of a rocky slope; safety factor (FS) or shear strength reduction (SRF) and failure probability (PF). Due to this, general methods of rock slope stability were used; cinematic analysis and numerical methods. Probabilistic analyses were conducted by the method of points’ estimation for more reliability in the results of numerical methods. Having in the cinematic analysis results a probability of glide plane by direct toppling of 44.41%, the values of average safety obtained by the probabilistic analysis with numerical methods in SFR are; for static conditions FS or SRF 2.27 and PF 0.0% and for pseudostatical conditions a FS or SRF 1.21 and PF 2.98%. Due to this, we concluded that the slope is stable in static and pseudostatic conditions, considering the results of cinematic analysis, were observed tension cracks on the top of the slope which failed by direct toppling depending of the intensity of trigger factors. Keywords: Rock Mass, probabilistic analysis, safety factor (FS), stress reduction factor (SRF), failure probability (PF).

Study on the Reliability of Loess Cutting Slope Considering the Variability of Soil-Water Characteristic Parameters

2012 ◽  
Vol 446-449 ◽  
pp. 1967-1972
Author(s):  
Yan Liang ◽  
Li Juan Huang ◽  
Xian Li Xing ◽  
Ping Li ◽  
Tong Lu Li
Keyword(s):  
Slope Stability ◽  
Soil Water ◽  
Failure Probability ◽  
Reliability Index ◽  
Factor Of Safety ◽  
Stability Calculation ◽  
Malan Loess ◽  
Cutting Slope ◽  
Geological Conditions ◽  
The Mean

The complexity of the geological conditions and the non-uniformity of geotechnical material make the study of slope stability with big uncertainties, so it is necessary to analyze the reliability of slope. In this paper, firstly, the matrix suction of Malan loess in Gansu Province is measured by tension meter, and a fitted soil-water characteristic curve (SWCC) is obtained according to the empirical formula; then SWCC parameters of Malan loess such as a, n and θs (saturation volumetric water content) are thought as random variables, the method of simplified Bishop is used to calculate of slope stability, and the reliability of cutting slope of Malan loess is analyzed according to Rosenbleuth method. Through calculating, obtain mean factor of safety, failure probability and reliability index of the slope. After analyzing the relations between mean factor of safety, failure probability, reliability index and variability of parameters, the results show that, the factor of safety is 1.005 and it is stable when the variability of SWCC parameters are not considered. When variation coefficients of a, n and θs are all 0.3, the average factor of safety is 1.051, the reliability index is 10.94 and failure probability is 29.81%. It is obvious that variability of SWCC parameters has certain influence on stability of the slope. In parameters of SWCC, comparing with a and θs, the variability of n has the most important influence on the mean factor of safety and failure probability. But the corresponding reliability index is minimum (the change ratios of the mean factor of safety， failure probability and reliability index with variation coefficient of n are 0.37，3.247 and 282.0 respectively). So variation level of n should be specially taken into account in reliability analysis of the slope. This research provides an important basis for the determination of the SWCC parameters of Malan loess, the stability calculation, stability estimation and prevention sliding of loess cutting slope caused by rainfall.

scholarly journals Probability Characteristics, Area Reduction, and Wind Directionality Effects of Extreme Pressure Coefficients of High-Rise Buildings

2021 ◽  
Vol 11 (15) ◽  
pp. 7121
Author(s):  
Shouke Li ◽  
Feipeng Xiao ◽  
Yunfeng Zou ◽  
Shouying Li ◽  
Shucheng Yang ◽  
...  
Keyword(s):  
Probability Distribution ◽  
Pressure Coefficient ◽  
Wind Pressure ◽  
Extreme Pressure ◽  
Distribution Law ◽  
Distribution Fitting ◽  
Pressure Coefficients ◽  
High Rise ◽  
Area Reduction ◽  
The Mean

Wind tunnel tests are carried out for the Commonwealth Advisory Aeronautical Research Council (CAARC) high-rise building with a scale of 1:400 in exposure categories D. The distribution law of extreme pressure coefficients under different conditions is studied. Probability distribution fitting is performed on the measured area-averaged extreme pressure coefficients. The general extreme value (GEV) distribution is preferred for probability distribution fitting of extreme pressure coefficients. From the comparison between the area-averaged coefficients and the value from GB50009-2012, it is indicated that the wind load coefficients from GB50009-2012 may be non-conservative for the CAARC building. The area reduction effect on the extreme wind pressure is smaller than that on the mean wind pressure from the code. The recommended formula of the area reduction factor for the extreme pressure coefficient is proposed in this study. It is found that the mean and the coefficient of variation (COV) for the directionality factors are 0.85 and 0.04, respectively, when the orientation of the building is given. If the uniform distribution is given for the building’s orientation, the mean value of the directionality factors is 0.88, which is close to the directionality factor of 0.90 given in the Chinese specifications.

scholarly journals Admixing Chaff with Straw Increased the Residues Collected without Compromising Machinery Efficiencies

Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1766 ◽  
Author(s):  
Alessandro Suardi ◽  
Sergio Saia ◽  
Walter Stefanoni ◽  
Carina Gunnarsson ◽  
Martin Sundberg ◽  
...  
Keyword(s):  
Energy Production ◽  
Dry Weight ◽  
Global Scale ◽  
Unit Weight ◽  
Residual Biomass ◽  
Energy Needs ◽  
The Mean ◽  
Field Efficiency ◽  
The One ◽  
Staple Crop

The collection of residues from staple crop may contribute to meet EU regulations in renewable energy production without harming soil quality. At a global scale, chaff may have great potential to be used as a bioenergy source. However, chaff is not usually collected, and its loss can consist of up to one-fifth of the residual biomass harvestable. In the present work, a spreader able to manage the chaff (either spreading [SPR] on the soil aside to the straw swath or admixed [ADM] with the straw) at varying threshing conditions (with either 1 or 2 threshing rotors [1R and 2R, respectively] in the combine, which affects the mean length of the straw pieces). The fractions of the biomass available in field (grain, chaff, straw, and stubble) were measured, along with the performances of both grain harvesting and baling operations. Admixing chaff allowed for a slightly higher amount of straw fresh weight baled compared to SPR (+336 kg straw ha−1), but such result was not evident on a dry weight basis. At the one time, admixing chaff reduced the material capacity of the combine by 12.9%. Using 2R compared to 1R strongly reduced the length of the straw pieces, and increased the bale unit weight; however, it reduced the field efficiency of the grain harvesting operations by 11.9%. On average, the straw loss did not vary by the treatments applied and was 44% of the total residues available (computed excluding the stubble). In conclusion, admixing of chaff with straw is an option to increase the residues collected without compromising grain harvesting and straw baling efficiencies; in addition, it can reduce the energy needs for the bale logistics. According to the present data, improving the chaff collection can allow halving the loss of residues. However, further studies are needed to optimise both the chaff and the straw recoveries.

Sign in / Sign up

Export Citation Format

Share Document