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1
Md Ghazaly, Zuhayr, Mustaqqim Abdul Rahim, Kok Alfred Chee Jee, Nur Fitriah Isa e Liyana Ahmad Sofri. "Landslide Simulation Using Limit Equilibrium and Finite Element Method". Materials Science Forum 857 (maggio 2016): 555–59. http://dx.doi.org/10.4028/www.scientific.net/msf.857.555.
Testo completoAbstract (sommario):
Slope stability analysis is one of the ancient tasks in the geotechnical engineering. There are two major methods; limit equilibrium method (LEM) and finite element method (FEM) that were used to analyze the factor of safety (FOS) to determine the stability of slope. The factor of safety will affect the remediation method to be underdesign or overdesign if the analysis method was not well chosen. This can lead to safety and costing problems which are the main concern. Furthermore, there were no statement that issued one of the analysis methods was more preferred than another. To achieve the objective of this research, the soil sample collected from landslide at Wang Kelian were tested to obtain the parameters of the soils. Then, those results were inserted into Plaxis and Slope/W software for modeling to obtain the factor of safety based on different cases such as geometry and homogenous of slope. The FOS obtained by FEM was generally lower compared to LEM but LEM can provide an obvious critical slip surface. This can be explained by their principles. Overall, the analysis method chosen must be based on the purpose of the analysis.
2
Kong, Ying, Hua Peng Shi e Hong Ming Yu. "Analysis of Unstable Rock-Mass Stability Based on Limit Equilibrium Method and Strength Reduction Method". Applied Mechanics and Materials 858 (novembre 2016): 73–80. http://dx.doi.org/10.4028/www.scientific.net/amm.858.73.
Testo completoAbstract (sommario):
With the slope unstable rock masses of a stope in Longsi mine, Jiaozuo City, China as the target, we computed and analyzed the stability of unstable rock masses using a limit equilibrium method (LEM) and a discrete element strength reduction method (SRM). Results show that the unstable rock masses are currently stable. Under the external actions of natural weathering, rainfall and earthquake, unstable rock mass 1 was manifested as a shear slip failure mode, and its stability was controlled jointly by bedding-plane and posterior-margin steep inclined joints. In comparison, unstable rock mass 2 was manifested as a tensile-crack toppling failure mode, and its stability was controlled by the perforation of posterior-margin joints. From the results of the 2 methods we find the safety factor determined from SRM is larger, but not significantly, than that from LEM, and SRM can simulate the progressive failure process of unstable rock masses. SRM also provides information about forces and deformation (e.g. stress-strain, and displacement) and more efficiently visualizes the parts at the slope that are susceptible to instability, suggesting SRM can be used as a supplementation of LEM.
3
Syamsul, Syamsul, Ichsan Rauf, Kusnadi Kusnadi e Nyong Hamin. "Road Slope Stability Analysis with Limit Equilibrium Method". IJEBD (International Journal of Entrepreneurship and Business Development) 6, n. 2 (31 marzo 2023): 345–53. http://dx.doi.org/10.29138/ijebd.v6i2.2129.
Testo completoAbstract (sommario):
Purpose: Landslides are hydrometeorological disasters frequently occurring in many places, particularly during the wet season. Slope stability analysis is the initial stage in defining countermeasures to prevent slope failure and mitigate the negative consequences. This study aims to apply the Limit Equilibrium Method (LEM) to examine the slope stability of the Dufadufa - Jambula road, with the SLIDE version 6.0 application serving as an analytical tool.
Design/methodology/approach: Researchers use field measurement data to build a slide application slope model. The soil data used as input parameters are derived using the Robertson chart to interpret the sonder test findings.
Findings: According to the results, the minimal slope factor of safety (fs) at the area under consideration is 0.247. It demonstrates that the road slope, which is the study location, is in critical condition; in other words, the slope of the Jambula-Dufadufa road segment has the potential to undergo a slide.
Paper type: Research paper
4
Li, Hong Jun, Yan Yi Zhang e Zu Wen Yan. "A Further Study on Soil Slope Stability Analysis by Finite Element Slip Surface Stress Method". Applied Mechanics and Materials 204-208 (ottobre 2012): 492–501. http://dx.doi.org/10.4028/www.scientific.net/amm.204-208.492.
Testo completoAbstract (sommario):
In this paper, it proves that the necessary and sufficient condition for the potential sliding body reaching the ultimate limit equilibrium state is that the summation of shear stresses along the sliding surface equals to that of resistant shear strength. Based on the rigorous theory analyses and derivations, it is clearly shown that the definition of factor of safety (FOS) in the slip surface stress method (SSSM) is irrelevant with the shape of slip surface. Thus, the authors demonstrate that the FOS of noncircular slip surface can also be defined as the ratio of the sum of resistant sliding force along slip surface to that of sliding force. Furthermore, the physical meaning of the FOS in the SSSM, which can be taken as the average evaluation of the strength reduction coefficient that makes the sliding body reach the ultimate limit equilibrium state along the slip surface in nature, is formulated on the basis of strength reserving theory rather than the overloading theory like that in the Limit Equilibrium Method (LEM) and the Shear Strength Reduction Method (SSRM). Finally, the factors of safety (FOS) and the locations of critical failure surfaces obtained by the SSSM, LEM and SSRM are compared for various geotechnical practices. It is found that the SSSM can achieve precise and reasonable stability assessments for the soil slopes on the basis of actual stress field. Consequently, compared with the LEM and SSRM, the SSSM is demonstrated to be effective and efficient alternative approach for routine analysis and design in geotechnical engineering practice with a high level of confidence.
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Yunus, Ahmad Anwar Mohd, Anuar Kasa, Zamri Chik e Taha Mohd Raihan. "Stability Analyses of an Earth Dam Using Limit Equilibrium and Finite Element Methods". Key Engineering Materials 462-463 (gennaio 2011): 319–24. http://dx.doi.org/10.4028/www.scientific.net/kem.462-463.319.
Testo completoAbstract (sommario):
The objective of this research is to study the relationships between the stability of earth dam and its soil strength parameters. The soil strength parameters include cohesion, unit weight of soil and angle of friction. GeoStudio, commercially available software, was used to obtain the overall factor of safety using limit equilibrium method (LEM) and finite element method (FEM). Tables to show the relationships among soil strength parameters for factor of safety 1.0 and 1.5 are presented in this paper.
6
Li, Hongjun, Hong Zhong, Zuwen Yan e Xuedong Zhang. "Particle Swarm Optimization Algorithm Coupled with Finite Element Limit Equilibrium Method for Geotechnical Practices". Mathematical Problems in Engineering 2012 (2012): 1–14. http://dx.doi.org/10.1155/2012/498690.
Testo completoAbstract (sommario):
This paper proposes a modified particle swarm optimization algorithm coupled with the finite element limit equilibrium method (FELEM) for the minimum factor of safety and the location of associated noncircular critical failure surfaces for various geotechnical practices. During the search process, the stress compatibility constraints coupled with the geometrical and kinematical compatibility constraints are firstly established based on the features of slope geometry and stress distribution to guarantee realistic slip surfaces from being unreasonable. Furthermore, in the FELEM, based on rigorous theoretical analyses and derivation, it is noted that the physical meaning of the factor of safety can be formulated on the basis of strength reserving theory rather than the overloading theory. Consequently, compared with the limit equilibrium method (LEM) and the shear strength reduction method (SSRM) through several numerical examples, the FELEM in conjunction with the improved search strategy is proved to be an effective and efficient approach to routine analysis and design in geotechnical practices with a high level of confidence.
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Li, Yong Quan, Hang Jing, Qing Huan Wang e Jun Fu Chen. "Stability Analysis of Soil Slope and the Design of Anti-Slide Piles during Unsteady Seepage". Applied Mechanics and Materials 204-208 (ottobre 2012): 689–93. http://dx.doi.org/10.4028/www.scientific.net/amm.204-208.689.
Testo completoAbstract (sommario):
Principle of calculation of water and earth pressures together by Limit Equilibrium Method (LEM) is introduced, and coupled deformation and seepage analysis is conducted by Finite Element Method (FEM ).The response of one soil slope is simulated during rapid drawdown of water level by LEM and FEM. The results calculated show that seepage upraises the critical slip surfaces, and critical slip surfaces and safety factors by two ways are pretty close. To assure the safety of the slope, the design of anti-slide piles is carried out. Those ways used may provide reference to engineering practice.
8
Tan, Wen Hui, Ya Liang Li e Cong Cong Li. "Research on 2D Limit Equilibrium Method of Slopes Considering the Effect of Horizontal In Situ Stress". Advanced Materials Research 671-674 (marzo 2013): 245–50. http://dx.doi.org/10.4028/www.scientific.net/amr.671-674.245.
Testo completoAbstract (sommario):
At present, in-situ stress was not considered in Limit Equilibrium Method (LEM) of slopes, the influence of in-situ stress is very small on the stability of conventional slopes, but in deep-depressed open-pit mines, the influence should not be neglected. Formula for calculating the Factor of Safety (FOS) under the effect of horizontal in-situ stress was deduced using General Slice Method (GSM) of two-dimensional (2D) limit equilibrium method in this paper，a corresponding program SSLOPE was built, and the software was used in a deep- depressed open-pit iron mine. The results show that the FOS of the slope decreased by 20% when horizontal in-situ stress is considered, some reinforcements must be taken. Therefore, the influence of in-situ stress on slope stability should be taken into account in deep open –pit mines.
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Luden, Alesandro Sejo, I. Gde Budi Indrawan e Dwikorita Karnawati. "Slope stability analyses by circular failure chart and limit equilibrium methods: the inlet and outlet of diversion tunnel of Bolango Ulu Dam, Indonesia". E3S Web of Conferences 325 (2021): 01015. http://dx.doi.org/10.1051/e3sconf/202132501015.
Testo completoAbstract (sommario):
The objective of this research is to evaluate the stability of the natural slopes at the inlet and outlet portals of the Bolangu Ulu diversion tunnel, Gorontalo. The natural slopes were considered stable, and therefore slope stability analyses were not carried out previously in the tunnel portal design. The slope stability analyses were carried out using the Circular Failure Chart (CFC) and Limit Equilibrium Methods (LEM). Input data for the slope stability analyses were obtained from field mapping and laboratory testing of soil and rock samples. The results show that the portal slopes consist of diorite and residual soil. Both stability analysis methods yield nearly the same results. The slope at the outlet section had the factor of safety (FOS) values of 1.29 and 1.30 based on the CFC method and LEM, respectively, indicating the slope in a stable condition. However, the slope at the inlet section had the FOS values of 1.01 and 1.07 based on the CFC method and LEM, respectively, indicating the slope in a critical condition. The results suggest that stabilization of the portal slopes, particularly the portal slope at the inlet section, is required to prevent slope failures under static and earthquake loads.
10
Ukleja, Janusz. "Stability estimation of slopes with determined slip surface by the MSTAB-3D method based on sliding body limit equilibrium analysis". MATEC Web of Conferences 262 (2019): 04004. http://dx.doi.org/10.1051/matecconf/201926204004.
Testo completoAbstract (sommario):
The method developed for this study, established on the premises of the limit equilibrium flat analysis for a spatial solution, is a modification of the STAB-3D method, previously described by the author. It combines the analyses methods of 2D slices of flat cross–sections with the spatial analyses methodology rooted in a specific breakdown of a landslide sliding body into 3D elements assuming some simplifying solution. However, this method is solely applicable in case of a landslide failure with a stipulated slip surface and with a consistent decline of a determined slide direction. Such a method was developed in the article published earlier, which provided then its basic assumptions and the equilibrium formulations. The following publication thereof, presents overall suppositions for this method as well as its modification involving the resultant forces brought to the equilibrium with the generalized slide direction. Apart from that, a comparative analysis was carried out on the impact of this modification applicability of the obtained results with regard to the STAB-3D method. The algorithm was also presented concerning the modified method with its results being compared to a couple of selected methods LEM (limit equilibrium method). The undertaken analysis reveals that the modified MSTAB-3D method determines stability indicators that are very similar to its earlier version. Moreover, the results occur to be also approximating the values obtained in the course of other methods with regard to the flat cross-section analysis.
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Aung, T. Z., C. T. T. Naing, L. C. Nguyen e K. T. Nguyen. "A comparison of countermeasures against landslide on the road No.152, Sapa Town, Lao Cai Province, Vietnam". IOP Conference Series: Materials Science and Engineering 1289, n. 1 (1 agosto 2023): 012093. http://dx.doi.org/10.1088/1757-899x/1289/1/012093.
Testo completoAbstract (sommario):
Abstract Landslide hazards are one of the most common geological disasters due to the impacts of natural factors, mainly rainfall, and human activities, such as the construction of transport infrastructure and mining projects. In Vietnam, most of the landslides and slippage frequently occur in mountainous areas, especially in Lao Cai province during the rainy season. In 2021, a slope failure happened near the Mong Hoa valley, on Road No. 152, sections Km 2+728.26–Km 2+827.04 in Cau May ward, Sapa town, Lao Cai province. In this study, topographical features, geomorphological features, hydrological features, geological investigation, and laboratory tests were performed to analyse the slope stability. This study used the Limit Equilibrium Method (LEM) and the Finite Element Method (FEM) to analyse the slope stability, and several countermeasures were proposed for this slope such as the retaining wall, ground anchors, and soil nails. This numerical result showed that the ground anchors and soil nails are the suitable method to prevent the instability of the slope. This study shows that compared with the traditional LEM method and advanced FEM method is that it can capture more results not only safety factor but also horizontal displacement and load anchor result. As a result, this analysis showed that the safety factor value in the finite element method was greater than that in the limit equilibrium method.
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Mohamed, Tariq, Anuar Kasa e Taha Mohd Raihan. "Prediction of Safety Factor for Slope Designed with Various Limit Equilibrium Methods". Key Engineering Materials 462-463 (gennaio 2011): 611–15. http://dx.doi.org/10.4028/www.scientific.net/kem.462-463.611.
Testo completoAbstract (sommario):
The purpose of this study is to predict the stability of slope using adaptive neuro fuzzy inference system (ANFIS). Based on limit equilibrium theory, four different methods of analyses, i.e. Morgenstern-Price, Janbu, Bishop and Ordinary were used to calculate the overall safety factor of various slope designs. Neuro-fuzzy inference system was used to map from a given input to an output. Important parameters such as height of slope (H), unit weight of soil (γ), angle of slope (θ), coefficient of cohesion (c) and internal angle of friction (ф) were used as the input parameters while overall safety factor was the output. ANFIS model to predict the stability of the slopes was generated from the calculated data. Results showed that factors of safety predicted using ANFIS agreed well with factors of safety calculated using Limit Equilibrium Methods (LEM).
13
Q. Arca, Ma Catherine, e Glen A. Lorenzo. "Landslide hazard mapping using limit equilibrium method with GIS application of roadway traversing mountain slopes: The case of Kitaotao Bukidnon, Philippines". Journal of Nepal Geological Society 55, n. 1 (4 giugno 2018): 93–101. http://dx.doi.org/10.3126/jngs.v55i1.22796.
Testo completoAbstract (sommario):
The national highway section of the Municipality of Kitaotao along the Davao City route plays a vital role in the transport of goods and services in the region. However, this national highway is prone to rainfall-induced landslides. Records show that almost every year this highway is being disrupted by landslide and road clearing operations would take several hours or even up to several days. This study aimed to improve the present landslide hazard map using Limit Equilibrium Method (LEM) and GIS techniques in order to present the spatial distribution of Factor of Safety (FS) in the area. A LEM based software (SLOPE /W) was utilized in the present study and Bishop Simplified slope stability model was adopted in calculating the FS. Geotechnical properties like cohesion, friction angle and unit weight were used in the analyses. The soil thickness data gathered were correlated to the slope angle in order to determine the spatial distribution of soil thickness in the area. The LHZM revealed that areas with low to very low stability are extensively found in the southern part and some areas in the northern portion. The accuracy of the model was validated through actual field observations and also by overlying the landslide inventory over the LHZM. It was found that 77.80 % of inventoried landslides are in low to very low stability zones. The present study adapts a deterministic approach using LEM of slope stability analysis and clusters the hazard zonation in terms of the spatial variation of FS in every 20 m x 20 m slope area employing GIS techniques; hence, this provides better insight on the landslide susceptibility throughout the study area and can be used directly for engineering design purposes.
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Deng, Dong-ping, Liang Li e Lian-heng Zhao. "Limit equilibrium method (LEM) of slope stability and calculation of comprehensive factor of safety with double strength-reduction technique". Journal of Mountain Science 14, n. 11 (27 settembre 2017): 2311–24. http://dx.doi.org/10.1007/s11629-017-4537-2.
Testo completo
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Rashid, Mehboob ur, Waqas Ahmed, Ihtisham Islam, Petros Petrounias, Panagiota P. Giannakopoulou e Nikolaos Koukouzas. "Impact of Climate Change on the Stability of the Miacher Slope, Upper Hunza, Gilgit Baltistan, Pakistan". Climate 11, n. 5 (8 maggio 2023): 102. http://dx.doi.org/10.3390/cli11050102.
Testo completoAbstract (sommario):
Especially in recent years, the study of landslide phenomena is considered as very important because of the effects of climate change. The aim of this paper is to examine the stability of the slope located in Miacher Nagar village along the Hunza River (HR), using the Limit Equilibrium Method (LEM). The Miacher slope rises to a height of 900 m from the foot of the Hunza River and has a base angle of 50 degrees. Meta-sediments and quaternary recent glaciated deposits make up the majority of the slope’s composition. The slope movement of Miacher was first triggered in 1995, and was further triggered in 2010 and 2013. The slope was geologically, geomorphologically, geotechnically and geochemically investigated as well as modeled by Slope/w to determine the safety factor. Soil samples were analyzed for their geotechnical, geological and geomorphological properties. The Limit Equilibrium Method (LEM) was employed in this study to analyze the Factor of Safety (FOS) of the slope, based on assumptions of the Morgenstern and Price, Ordinary, Janbu and Bishop Methods, using the Slope/w software. Various factors, including pore water pressure, unit weight, cohesion, angle of internal friction and overburden, were examined by analyzing different scenarios. The findings showed that an increase in cohesion and angle of internal friction resulted in an increase in FOS, whereas an increase in unit weight and overburden caused a decrease in FOS. The influence of pore water pressure was positive to a certain extent, but a further increase led to a significant reduction in FOS. The results showed that the Miacher slope is currently stable, as all FOS values were greater than one, based on the existing strength parameters and simulated results obtained using Slope/w.
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Ma, Lili, Zhiyuan Zhao, Kuanjun Wang, Yupei Huang, Haochen Liu e Qinfeng Yang. "Stability Analysis of Earth Dams in a Landfill: A Case Study". Journal of Physics: Conference Series 2519, n. 1 (1 giugno 2023): 012010. http://dx.doi.org/10.1088/1742-6596/2519/1/012010.
Testo completoAbstract (sommario):
Abstract The dam is an important structure of landfill, and its stability is vital to the landfill safety. However, due to lack of specific design specifications, the design and stability of landfill dam have been conducted based on several relevant specifications. Therefore, taking the landfill project in Hangzhou for example, stability analyses of three temporal earth dams are performed, based on limit equilibrium method (LEM) and strength reduction method (SRM). It is found that two dams are stable, while the third one is in basically stable state by LEM and in understable state by SRM, respectively. Then it is recommended that the construction should strictly follow the design requirements, backfilling simultaneously on both sides of the dam. Finally, the analytical framework or few conclusions in this paper is expected to be a reference for earth dams in landfill.
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Oreste, Pierpaolo, e Silvia Soldano. "Static and dynamic analyses of the stability of mining wastes (Ravaneti) in the Carrara marble area (Apuan Alps, Italy) / Analiza statyczna i dynamiczna stabilności hałd odpadów górniczych w regionie wydobycia marmurów Carrara (Alpy Apuańskie, Italia)". Archives of Mining Sciences 57, n. 3 (1 dicembre 2012): 667–86. http://dx.doi.org/10.2478/v10267-012-0043-0.
Testo completoAbstract (sommario):
Abstract The problem of the stability of “ravanetos” (debris piles of mining waste material extracted from the Apuan Alps, Italy) is very relevant, because of the consequences a landslide would have on the people and the existing civil infrastructures throughout the territory. In this work, the stability of two ravanetos that can be considered as representative of those in the Carrara area has been studied: the Polvaccio ravaneto, a recent type of debris pile and the Torrione-Tecchione, an old debris pile at present undergoing re-naturalisation. The study using the LEM (Limit Equilibrium Method) in a static and pseudo-static field, has made it possible to first carry out a back-analysis to define the most probable apparent cohesion and friction angle values of the material that makes up the ravanetos. Subsequently, it was possible to determine the intensity of the seismic wave that would be able to lead the two ravanetos to limit stability conditions and to determine the probability of such a seismic wave occurring in the next 50 years. A more accurate analysis, carried out with a numerical method in the dynamic field, of the most critical condition (the Polvaccio ravaneto) has led to more conservative results (higher safety factors) than those obtained with the LEM. This result allows us to reveal how the LEM can be considered a cautionary instrument to judge the stability of debris piles during a seismic event and that the likelihood of a landslide occurring in the two studied representative ravanetos over the next 50 years is very slim.
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Peng, Pu, Ze Li, Xiaoyan Zhang, Wei Zhang e Wushu Dong. "Efficient Method for Calculating Slope Failure Risk Based on Element Failure Probability". Applied Sciences 13, n. 8 (11 aprile 2023): 4806. http://dx.doi.org/10.3390/app13084806.
Testo completoAbstract (sommario):
The finite element method (FEM) and the limit equilibrium method (LEM) are commonly used for calculating slope failure risk. However, the FEM needs to carry out post-processing to estimate slope sliding surface, while the LEM requires assumption of the shape and location of the sliding surface in advance. In this paper, an element failure risk method (EFR) for calculating soil slope failure risk is proposed based on element failure probability (EFP) acquired by plastic limit analysis. The proposed method does not require any assumptions about failure modes. Firstly, the non-common-node triangle element is used to discrete the slope then the random field is generated based on the Cholesky decomposition midpoint method. According to the reliability stochastic programming model and solution strategy, the external overload coefficient, bulk overload coefficient, slope stability coefficient and velocity field of the slope under each random field are obtained, according to which the failure of the element is judged and the failure risk of the slope is calculated. In order to verify the correctness of the proposed method, two classical slopes are systematically analyzed. The research shows that compared with the traditional slope failure risk analysis method, the greatest advantage of the proposed method is that it can capture all failure modes of the slope and greatly simplify the calculation of the slope failure consequences of each failure mode. An efficient upper bound method (UBM) parallel program is prepared, which greatly improves the calculation efficiency.
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Rahman, Aftab Ur, Guangcheng Zhang, Salman A. AlQahtani, Hammad Tariq Janjuhah, Irshad Hussain, Habib Ur Rehman e Liaqat Ali Shah. "Geotechnical Assessment of Rock Slope Stability Using Kinematic and Limit Equilibrium Analysis for Safety Evaluation". Water 15, n. 10 (19 maggio 2023): 1924. http://dx.doi.org/10.3390/w15101924.
Testo completoAbstract (sommario):
The purpose of this study is to identify the leading causes of slope instability along a local highway in Anhui, People’s Republic of China. As part of the east expansion project, the mountain range will be excavated to create a two-way, nearly 30 m wide highway. The site’s topography consists of a hill with palm-shaped faces carved from limestone running along its sides. The geological characteristics and slope stability of the research area highlight the possibility of slope failure along both sides of the roadway. Slope stability analysis was performed in order to determine the failure mechanism and create a stable slope. Initial slope characterization and shear properties of the rock were determined by means of fieldwork and laboratory analysis. By causing wedging failure and toppling collapse, the bedding joints and discontinuity orientations increase instability, as determined by a kinematic analysis performed with DIP.6 software. The Limit Equilibrium Method (LEM) of analysis is presented in the software Slide 6.020 to illustrate the instability of the slope. The unstable condition of the slopes was determined using empirical methods that were validated and enhanced by limit equilibrium analysis.
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Niemiec, Dominik, Roman Bulko e Juraj Mužík. "The Meshfree Localized Petrov-Galerkin Approach in Slope Stability Analysis". Civil and Environmental Engineering 15, n. 1 (1 giugno 2019): 79–84. http://dx.doi.org/10.2478/cee-2019-0011.
Testo completoAbstract (sommario):
Abstract The article focuses on the use of the meshfree numerical method in the field of slope stability computations. There are many meshfree implementations of numerical methods. The article shows the results obtained using the meshfree localized Petrov-Galerkin method (MLPG) – localized weak-form of the equilibrium equations with an often used elastoplastic material model based on Mohr-Coulomb (MC) yield criterion. The most important aspect of MLPG is that the discretization process uses a set of nodes instead of elements. Node position within the computational domain is not restricted by any prescribed relationship. The shape functions are constructed using just the set of nodes present in the simple shaped domain of influence. The benchmark slope stability numerical model was performed using the developed meshfree computer code and compared with conventional finite element (FEM) and limit equilibrium (LEM) codes. The results showed the ability of the implemented theoretical preliminaries to solve the geotechnical stability problems.
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Li, Liang, e Xuesong Chu. "Failure Mechanism and Factor of Safety for Spatially Variable Undrained Soil Slope". Advances in Civil Engineering 2019 (18 febbraio 2019): 1–17. http://dx.doi.org/10.1155/2019/8575439.
Testo completoAbstract (sommario):
This paper aims to investigate the differences in factor of safety (FS) and failure mechanism (FM) for spatially variable undrained soil slope between using finite element method (FEM) , finite difference method (FDM), and limit equilibrium method (LEM). The undrained shear strength of cohesive soil slope is modeled by a one-dimensional random field in the vertical direction. The FS and FM for a specific realization of random field are determined by SRT embedded in FEM- and FDM-based software (e.g., Phase2 6.0 and FLAC) and LEM, respectively. The comparative study has demonstrated that the bishop method (with circular failure surface) exhibits performance as fairly good as that of SRT both in FS and FM for the undrained slope cases where no preferable controlling surfaces such as hydraulic tension crack and inclined weak seams dominate the failure mechanism. It is, however, worthwhile to point out that unconservative FM is provided by the Bishop method from the aspect of failure consequence (i.e., the failure consequence indicated by the FM from the Bishop method is smaller than that from SRT). The rigorous LEM (e.g., M-P and Spencer method with noncircular failure surface) is not recommended in the stability analysis of spatially variable soil slopes before the local minima and failure to converge issues are fully addressed. The SRT in combination with FEM and/or FDM provides a rigorous and powerful tool and is highly preferable for slope reliability of spatially variable undrained slope.
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Liu, Zhenzhen, Tian Li, Yuxi Ding e Shuihua Jiang. "A Soil Tensile Strength Based Headcut Migration Model of Breach Side Slope". Water 12, n. 10 (23 settembre 2020): 2666. http://dx.doi.org/10.3390/w12102666.
Testo completoAbstract (sommario):
The headcut migration describes the physical process of breach side slope retreat that governs the widening of the breach. Modeling the growth of a breach due to embankment failure is the first step in mapping the resulting inundation in a floodplain. As removal of soil from the toe of the headcut effectively removes physical support for the upper part, the headcut fails on the plane normal to the direction of tensile stress. This process is a typical mode of tensile failure. A numerical model of the headcut migration was established by integrating the effects of the soil tensile strength, soil permeability and embankment geotechnical characteristics. Thus, a simple analytical equation was finally obtained to predict the critical length of the headcut. Furthermore, the presented model was verified by using the limit equilibrium method (LEM) for three typical embankment scales (2, 4 and 6 m high). The comparisons between the present model and the LEM show good agreements. The present model could provide a simple method to predict the critical length of the headcut migration and easily be adopted to breach widening models.
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Dinata, Edden Umaga, I. Gde Budi Indrawan e Arifudin Idrus. "Slope stability analysis of the drainage tunnel portal in Tanju Dam, Dompu District, West Nusa Tenggara". E3S Web of Conferences 325 (2021): 01016. http://dx.doi.org/10.1051/e3sconf/202132501016.
Testo completoAbstract (sommario):
This paper presents design results of the tunnel portal slopes at the Tanju Dam, Dompu, West Nusa Tenggara. The objective of this research was to analyse the stability of the tunnel portal slopes using circular failure chart (CFC) method, limit equilibrium method (LEM), and finite element method (FEM). Input parameters were obtained from drill core evaluations and laboratory tests. By considering the rock mass rating (RMR) values of rock masses, which are categorized as class II, at the two slopes, adjustments for the cohesion and inner friction angle values are made. The inlet slope (IL) have cohesion values of 350 kPa and 40º inner friction angle and the outlet slope (OL) have cohesion values of 400 kPa and 45º inner friction angle. The CFC method shows that the IL and OL have safety factor (FS) values of 3.5 and 3.44, respectively. The LEM shows that the IL and OL have the FS values of 3.69 and 3.65, respectively. Meanwhile, the FEM shows that the IL and OL have FS values of 4.78 and 4.79, respectively. The stability analysis results indicate that designed slopes are stable.
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Zhang, Guorong, Guangyin Lu, Chengzhi Xia, Dongxin Bai e Taoying Liu. "A Time-Scale Varying Finite Difference Method for Analyzing the Influence of Rainfall and Water Level on the Stability of a Bank Slope". Applied Sciences 13, n. 9 (23 aprile 2023): 5268. http://dx.doi.org/10.3390/app13095268.
Testo completoAbstract (sommario):
A time-scale varying finite difference method (TSFDM) was proposed to analyze the influence of rainfall infiltration and water level fluctuation on the stability of a bank slope in the Yunnan Pulang tailings pond. The stability of the slope obtained by the TSFDM and the limit equilibrium method (LEM) were compared. The result indicates that the TSFDM can obtain reliable spatiotemporal variation features of geotechnical parameters of the bank slope under different conditions. The water level fluctuation has a greater impact on the stability than rainfall infiltration. In addition, the safety factor decreases as the shear strain rate increases on the weathering interface. The safety factors under all conditions are smaller than one, so corresponding measures should be taken. The research provides references for preventing disasters caused by bank slope failure.
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Lakehal, Rida, e Lakhdar Djemili. "Studying the effect of a variation in the main parameters on stability of homogeneous earth dams using design experiment". Journal of Water and Land Development 34, n. 1 (26 settembre 2017): 173–79. http://dx.doi.org/10.1515/jwld-2017-0051.
Testo completoAbstract (sommario):
Abstract Deterministic approaches such as the limit equilibrium method (LEM) especially Bishop modified method has been traditionally used to evaluate the stability of embankment dams. However, the uncertainty associated with the material properties necessitates the use of the probabilistic method to account the sensitivity of this uncertainty on the response of the deterministic approaches. In this study, the authors propose the application of design experiment, especially central composite design (CCD) to determine the effects of independent uncertain parameters on the response of stability. A second-order polynomial model with cross terms is used to create an approximating function referred to as response surface for the implicit limit state surface, for which the input data were provided by stability analyses of different heights of homogeneous earth dams (10 m, 20 m, and 30 m) with a depth ratio of DH = 1.5 and a circular slip surface using the Bishop modified limit equilibrium method. The proposed models obtained from this application represent higher prediction accuracy. The study of the effect of geotechnical parameters (material properties of embankment) on safety factor show the importance of individual factors in level of linear effect with a positive effect of c’ or φ’ and a negative effect of H, γd, γsat and significant influence of two-factors interaction, the effect of c’ highly dependent on H, β, γd and φ’. Moreover, the effect of φ’ is dependent on the values of H and β. Lastly, the optimization of safety factor with respect to the range of values of material properties was made, and two failures modes are discussed which are (φ’, c’ reduction and γd increase).
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Belo, Jean Lucas dos Passos, Jefferson Lins da Silva e Paulo Ivo Braga de Queiroz. "Reliability Analysis of an Embankment Built and Reinforced in Soft Ground Using LE and FE". Sustainability 14, n. 4 (16 febbraio 2022): 2224. http://dx.doi.org/10.3390/su14042224.
Testo completoAbstract (sommario):
A coupling method is presented to integrate well-known geotechnical modeling commercial programs with a reliability one. Coupling enables us to use transformation methods, such as the first-order reliability method (FORM), to evaluate the reliability index (β) of a model, via the limit equilibrium (LEM) or the finite-element method (FEM). It was applied to a case study of a stage-constructed embankment on soft ground by considering two conditions, unreinforced and reinforced, to investigate its probabilistic stability. In addition, the value of β associated with a postconstruction settlement was acquired, and it showed one possibility that the coupling method is able to provide. The influence of the uncertainty level on reliability analysis was also analyzed. The outcomes were compared to the crude Monte Carlo simulation. As a result, the proposed approach was satisfactory, and the advantage of using it is presented; with a much lower computational cost than simulation methods, evaluation time may be up to 13.8 times faster than usual with great precision. Moreover, this approach can apply to other commercial programs widely used in practice.
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Dwinagara, Barlian, Raden Hariyanto, Oktarian Wisnu Lusantono e Prasodo Datu Prabandaru. "Geotechnical Perspective on Dozer-Push Method in Coal Mining Operations". RSF Conference Series: Engineering and Technology 1, n. 1 (23 dicembre 2021): 144–59. http://dx.doi.org/10.31098/cset.v1i1.388.
Testo completoAbstract (sommario):
The rapid increase of technological development is currently playing a role in the mining industry. The dozer push exploitation method is an alternative to the conventional truck and shovel method. Heavy dozers have the ability to move large amounts of waste material in short distances at a low cost, while trucks and shovels will be more economical if over long distances. Geotechnical assessment becomes one of the critical considerations in making a decision plan and slope design for mining activities where the dozer push activities were carried out. Material conditions greatly affect slope stability, which can be defined as material behavior based on the physical and mechanical properties of the material. The slope stability analysis method used in this study was a combination of two methods, the Limit Equilibrium Method (LEM) and Finite Element Method (FEM). These two combinations of analytical methods will strengthen the justification of the geotechnical perspective. By understanding the behavior of the material on a slope, the risk of a slope failure can be controlled and minimized using a geotechnical perspective. The parameters that will be studied in this study are the physical and mechanical properties of the material against several conceptual design options
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Rina Zusianti, Luthfi Amri Wicaksono e Paksitya Purnama Putra. "PENGGUNAAN COUNTERWEIGHT DAN SOIL NAILING SEBAGAI ALTERNATIF PERKUATAN LERENG SUNGAI GANDONG MAGETAN JAWA TIMUR PASCA LONGSOR". PADURAKSA: Jurnal Teknik Sipil Universitas Warmadewa 11, n. 2 (19 novembre 2022): 214–21. http://dx.doi.org/10.22225/pd.11.2.5534.214-221.
Testo completoAbstract (sommario):
Longsor terjadi di lereng Sungai Gandong Magetan. Lokasi sungai yang berada di tengah perkotaan mengakibatkan longsoran hampir mencapai rumah warga. Perlu dilakukan upaya peningkatan stabilitas lereng agar aman terhadap longsor. Analisis stabilitas lereng menggunakan metode LEM (Limit Equilibrium Method) dengan progam bantu Geoslope. Hasil analisis stabilitas lereng kondisi eksisting mendapatkan nilai faktor keamanan 0.379. Alternatif perkuatan yang direncanakan ialah pembuatan lereng counterweight. Perencanaan timbunan lereng counterweight sebanyak 4 tingkat dengan tinggi 3 m setiap tingkatnya. Hasil analisis stabilitas lereng counterweight mendapatkan nilai faktor keamanan sebesar 0.507. Area kritis berada pada bagian atas lereng sehingga ditambahkan perkuatan soil nailing. Hasil analisis stabilitas lereng counterweight dengan perkuatan soil nailing dan bronjong didapatkan nilai faktor keamanan sebesar 1.507. Sehingga perencanaan perkuatan lereng tersebut aman terhadap longsor.
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Habtemariam, Behailu G., Kelifa B. Shirago e Democracy D. Dirate. "Effects of Soil Properties and Slope Angle on Deformation and Stability of Cut Slopes". Advances in Civil Engineering 2022 (7 giugno 2022): 1–10. http://dx.doi.org/10.1155/2022/4882095.
Testo completoAbstract (sommario):
The impact of soil parameters and slope angle on the deformation and stability of cut slopes is critical for defining road project safety measurement. This study investigates the effect of soil properties and slope angle on the deformation and stability of cut slopes in general and the specific Arba Minch-Chencha upgrading road project. Forty-eight (48) analyses were carried out both in Slope/W and Plaxis 2D software for six cut slopes and analyzed for four different slope angles. Twenty-four (24) dataset samples were collected from six different cut-slope sites. These dataset samples were categorized in two situations, i.e., before and after water saturation for each cut slope. The limit equilibrium method (LEM) comparison clearly showed that the Spencer, Bishop, and Morgenstern-Price methods produced similar FOS. The Ordinary and Janbu approaches, on the other hand, underestimate the FOS. Most LEMs except Ordinary and Janbu methods that estimated higher FOS than finite element method (FEM) analysis. It is observed that the main reasons for the cut-slope instability were the provision of steep cut-slope angles, the existence of a high proportion of fine soil, and moisture content, which was observed in both Plaxis 2D (FEM) and Slope/W (LEM). It was concluded that the slope is more stable for the soil having few fine-grained fractions. Moreover, flattening the slope stabilizes the cut slopes based on the results obtained from both Plaxis 2D and Slope/W.
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LEE, SANG SOO. "Generalized critical-layer analysis of fully coupled resonant-triad interactions in boundary layers". Journal of Fluid Mechanics 347 (25 settembre 1997): 71–103. http://dx.doi.org/10.1017/s0022112097006617.
Testo completoAbstract (sommario):
The critical-layer analysis of the nonlinear resonant-triad interaction by Goldstein & Lee (1992) is extended to include viscous effects. A generalized scaling which is valid both for the quasi-equilibrium and non-equilibrium critical-layer analyses in zero- or non-zero-pressure-gradient boundary layers is obtained. A system of partial differential equations which governs the fully coupled non-equilibrium critical-layer dynamics is obtained and it is solved by using a numerical method. Amplitude equations and their viscous limits are also presented. The parametric-resonance growth rate of the non-equilibrium critical-layer solution with finite viscosity is larger than that of the viscous-limit quasi-equilibrium solution. The viscosity delays both the onset of the fully coupled interaction and the ultimate downstream location of the singularity. The difference between the non-equilibrium critical-layer solution and the corresponding quasi-equilibrium critical-layer solution becomes smaller, at least in the parametric resonance region, as the viscosity parameter becomes large. However, the non-equilibrium solution with finite viscosity always ends in a singularity at a finite downstream position unlike the viscous-limit solution.
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Kiernan, Michael, Mengwei Xuan, Jack Montgomery e J. Brian Anderson. "Integrated Characterization and Analysis of a Slow-Moving Landslide Using Geotechnical and Geophysical Methods". Geosciences 12, n. 11 (2 novembre 2022): 404. http://dx.doi.org/10.3390/geosciences12110404.
Testo completoAbstract (sommario):
Slope failures in roadway embankments are common occurrences and can lead to traffic disruptions and large costs to repair damage. In areas with high-plasticity clays, special attention must be paid to characterizing both the stratigraphy and the potential for strength loss. This study demonstrates the use of an integrated site characterization approach, which seeks to utilize results from geotechnical and geophysical tests to understand the behavior of a landslide in west Alabama. The timing and mechanism of the initial failure causing the preexisting shear plane at this site are not known. Results from electrical resistivity and seismic geophysical tests are integrated with information from borings and index tests to develop a representative cross-section for the landslide, and torsional ring shear results are used to measure the drained fully softened and residual strengths. Both the limit equilibrium (LEM) and strength reduction method (SRM) analyses are used to examine possible failure mechanisms. The results show good agreement between noncircular LEM and SRM analyses and indicate that the initial failure was likely due to undrained loading of the clay. Analyses utilizing the residual drained strength envelopes produce FS values significantly lower than 1 indicating the slope to be unstable when soil on the failure plane exists at the residual state. Sensitivity analyses suggest that the combined effect of lowering the water table and strength recovery may explain the intermittent nature of movements.
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Suhendra, Andryan, Muhammad Raihan e I. Gede Mahardika Susila. "DEVELOPMENT OF A SIMPLE DESIGN CHART AS AN EVALUATION OF SLOPE STABILITY". IOP Conference Series: Earth and Environmental Science 998, n. 1 (1 febbraio 2022): 012020. http://dx.doi.org/10.1088/1755-1315/998/1/012020.
Testo completoAbstract (sommario):
Abstract Landslides can damage public facilities and also have a negative impact on the community. This impact will be able to minimize when knowing the slope stability by carrying out the analysis to determine the factor of safety against landslide. The most accurate results usually get from calculation through computer software, but sometime it will take time and also not all of the designer have the sophisticated software. Another method in predicting the slope stability is using design chart as carried out in this study. The aim of this study is as a sustainable development of a simple chart to help the designer in predicting the landslide possibility. The graph will consist of the relationship between the slope height and the factor of safety for several soil strength parameter and slope angles. The slope stability analysis method will be based on LEM (Limit Equilibrium Method) through Bishop’s equation. The result is then being tested through case study and comparing with the other existing design chart and show a satisfactory result.
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S’habou, Rakia, e Zeineb Ben Salem. "The use of geomembrane as a remediation towards a sustainable OMWW landfilling: Case study of Agareb site in Sfax, Tunisia". E3S Web of Conferences 368 (2023): 02005. http://dx.doi.org/10.1051/e3sconf/202336802005.
Testo completoAbstract (sommario):
In Tunisia, olive mill wastewater (OMWW) locally named ‘margine’ constitutes a serious problem due to its huge amount, of about one million ton per year, and the high pollutant load resulting in the excessive chemical oxygen demand (COD) values and the presence of phytotoxic and antibacterial polyphenols. The most common treatment of OMWW was storage in evaporation ponds which are authorized but uncontrolled. Thus, it represents a potential contamination source of natural resources (air, soil and water) via infiltration. This study aims at a critically analysing the OMWW storage management on the site of Agareb in Sfax, Tunisia. The data relating to the OMWW production highlights that it exceeds its storage capacity due to the uncomplete OMWW evaporation. The geotechnical investigations confirmed the spread of OMWW through and below the storage basins. Furthermore, multiple slope sliding has been observed within embankments separating the OMWW storage basins. Faced with this alarming situation, the assessment of the incorporation of geomembrane is analysed in order to ensure the sustainability of OMWW landfilling. The slope stability analysis based on limit-equilibrium method (LEM) using Midas-Soil works software was investigated. The use of geomembrane can secure the slope stability and limit OMWW infiltrations in the landfill body and sub-soils in the studied site.
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Nanehkaran, Yaser A., Zhu Licai, Jin Chengyong, Junde Chen, Sheraz Anwar, Mohammad Azarafza e Reza Derakhshani. "Comparative Analysis for Slope Stability by Using Machine Learning Methods". Applied Sciences 13, n. 3 (25 gennaio 2023): 1555. http://dx.doi.org/10.3390/app13031555.
Testo completoAbstract (sommario):
Earth slopes’ stability analysis is a key task in geotechnical engineering that provides a detailed view of the slope conditions used to implement appropriate stabilizations. In the stability analysis process, calculating the safety factor (F.S) plays an essential part in the stability assessment, which guarantees operations’ success. Providing accurate and reliable F.S can be used to improve the stability analysis procedure as well as stabilizations. In this regard, researchers used computational intelligent methodologies to reach highly accurate F.S calculations. The presented study focused on the F.S estimation process and attempted to provide a comparative analysis based on computational intelligence and machine learning methods. In this regard, the well-known multilayer perceptron (MLP), decision tree (DT), support vector machines (SVM), and random forest (RF) learning algorithms were used to predict/calculate F.S for the earth slopes. These machine learning classifiers have a strong capability predict the F.S under certain conditions for slope failures and uncertainties. These models were implemented on a dataset containing 100 earth slopes’ stabilities, recorded based on F.S from various locations in the provinces of Fars, Isfahan, and Tehran in Iran, which were randomly divided into the training and testing datasets. These predictive models were validated by Janbu’s limit equilibrium analysis method (LEM) and GeoStudio commercial software. Regarding the study’s results, MLP (accuracy = 0.901/precision = 0.90) provides more accurate results to predict the F.S than other classifiers, with good agreement with LEM results. The SVM algorithm follows MLP (accuracy = 0.873/precision = 0.85). Regarding the estimated loss function, MLP obtained a 0.29 average loss in the F.S prediction process, which is the lowest rate. The SVM, DT, and RF obtained 0.41, 0.62, and 0.45 losses, respectively. This article tried to fill the gap in traditional analysis procedures based on advanced procedures in slope stability assessments.
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Radani, Romario Rahmad, Yuliadi e Iswandaru. "Analisis Balik Kestabilan Lereng Penambangan Batubara di PT Banjarsari Pribumi Site Banjarsari Kecamatan Merapi Timur, Kabupaten Lahat, Provinsi Sumatera Selatan". Bandung Conference Series: Mining Engineering 2, n. 2 (1 agosto 2022): 448–57. http://dx.doi.org/10.29313/bcsme.v2i2.4082.
Testo completoAbstract (sommario):
Abstract. In this geotechnical analysis study the research uses the Limit Equilibrium Method (LEM) method to analyze single slopes and overall slopes. The input of material properties used comes from classification rock mass rating and the results of geotechnical mapping in the field which can also be applied for kinematic analysis on slopes that can represent other slopes to get the type of relaxation that can occur in the research area. Geotechnical analysis to be able to redesign slope geometry at PT Banjarsari Pribumi is based on the results of physical property tests, mechanical properties of rocks obtained from laboratory testing, and conducting geotechnical data in the field to be used as evaluation materials. The results of the overall slope stability analysis resulted in a cross-section of A-A' to a cross-section of G-G' and a single slope for waste material. Using new material properties and slope design it can be said that the slope is in a stable state or FK > 1.1 (Kepmen 1827). On the B-B' slope which is assumed to represent other slope conditions, kinematic analysis and potentially wedge avalanches.The overall slope stability analysis on the optimal lowwall slope has a slope height geometry design of 100 m, overall slope 290, bench width of 6 meters, bench height of 10 meters, and bench slope of 400, and interamp slope has a bench width of 13 meters.
Abstrak. Dalam kajian analisis geoteknik ini penelitian menggunakan metode kesetimbangan batas atau Limit Equilibrium Method (LEM) untuk menganalisis lereng tunggal, lereng interamp dan lereng keseluruhan. Adapun input material properties yang digunakan berasal dari pengklasifikasian massa batuan (RMR) dan hasil pemetaan geoteknik (geotechnical mapping) di lapangan yang juga dapat di aplikasikan untuk dilakukannya analisis kinematik pada lereng yang dapat mewakili lereng lainnya sehingga mendapatkan jenis kelongsoran yang dapat terjadi pada daerah penelitian. Analisis geoteknik untuk dapat meredesain geometri lereng di PT Banjarsari Pribumi ini berdasarkan hasil uji sifat fisik, sifat mekanis batuan yang diperoleh dari pengujian laboratorium dan melakukan penggambilan data geoteknik di lapangan untuk dijadikan bahan evaluasi. Hasil analisis kestabilan lereng keseluruhan menghasilkan penampang A-A’ hingga penampang G-G’ dan lereng tunggal untuk material waste. Dengan menggunakan material properties dan desain lereng yang baru dapat dikatakan bahwa lereng dalam keadaan stabil atau FK > 1,1 (Kepmen 1827). Pada lereng B-B’ yang diasumsikan dapat mewakili kondisi lereng lain dilakukannya analisis kinematik dan berpotensi adanya longsoran baji. Analisis kestabilan lereng keseluruhan pada lereng bagian lowwall yang optimal secara teoritis memiliki desain geometri tinggi lereng 100 m, overall slope 290, lebar bench 6 meter, tinggi bench 10 meter dan kemiringan bench 400, serta lereng interamp memiliki lebar bench 13 meter.
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Deris, Ashanira Mat, Badariah Solemon e Rohayu Che Omar. "A comparative study of supervised machine learning approaches for slope failure production". E3S Web of Conferences 325 (2021): 01001. http://dx.doi.org/10.1051/e3sconf/202132501001.
Testo completoAbstract (sommario):
Over the years, machine learning, which is a well-known method in artificial intelligent (AI) field has become a new trend and extensively applied in various applications to solve a realworld problem. This includes slope failure prediction. Slope failure is among the major geo-hazard phenomenon which gives the significant impact to the environment or human beings. The estimation of slope failure in slope stability analysis is a complex geotechnical engineering problem that involves many factors such as geology, topography, atmosphere, and land occupancy. Generally, slope failure can be estimated based on traditional methods such as limit equilibrium method (LEM) or finite equilibrium method (FEM). However, beside the methods are quite tedious and time consuming, LEM and FEM have their own limitations and do not guarantee the effectiveness when dealing against problem with various geometry or assumptions. Hence, the introduction of machine learning approaches provides the alternative tools for the prediction of slope failure. Current study applies two mostly used supervised machine learning approaches, support vector machine (SVM) and decision tree (DT) to predict the slope failure based on classification problem using historical cases. 148 of slope cases with six input parameters namely “unit weight, cohesion, internal friction angle, slope angle, slope height and pore pressure ratio and factor of safety (FOS) as an output parameter”, was collected from multinational dataset that has been extracted from the literature. For development of the prediction model, the slope data was divided into 80% training data and 20% testing data. The prediction result from testing data was validated based on statistical analysis. The result shows that SVM model has outperformed DT model by giving the prediction accuracy of 97%. ith the advent of technology and the introduction of computational intelligent methods, the prediction of slope failure using the machine learning (ML) approach is rapidly growing for the past few decades. This study employs an “artificial neural network” (ANN) to predict the slope failures based on historical circular slope cases. Using the feed-forward backpropagation algorithm with a multilayer perceptron network, ANN is a powerful ML method capable of predicting the complex model of slope cases. However, the prediction result of ANN can be improved by integrating the statistical analysis method, namely grey relational analysis (GRA), to the ANN model. GRA is capable of identifying the influencing factors of the input data based on the correlation level of the reference sequence and comparability sequence of the dataset. This statistical machine learning model can analyze the slope data and eliminate the unnecessary data samples to improve the prediction performance. Grey relational analysis-artificial neural network (GRANN) prediction model was developed based on six slope factors: unit weight, friction angle, cohesion, pore pressure ratio, slope height, and slope angle, with the factor of safety (FOS) as the output factor. The prediction results were analyzed based on accuracy percentage and receiver operating characteristic (ROC) values. It shows that the GRANN model has outperformed the ANN model by giving 99% accuracy and 0.999 ROC value, compared with 91% and 0.929.
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javed, Fahad, e Inamullah khan. "SLOPE STABILITY ANALYSIS AND MITIGATION ALONG CPEC ROUTE (KKH) BY USING ROCSCIENCE SLIDE MODELING;(A CASE STUDY OF LANDSLIDE AT HUMARRI, PAKISTAN". Scandic Journal Of Advanced Research And Reviews 2, n. 3 (13 giugno 2022): 070–80. http://dx.doi.org/10.55966/sjarr.2022.2.3.0043.
Testo completoAbstract (sommario):
Northern Pakistan is one of the most active and dangerous geological zones on the planet. As a result, several huge landslides have occurred in the area throughout history, destroying infrastructure, blocking the Hunza River, and seriously damaging the Karakoram highway. Due to the difficult logistics and wide distances involved, despite the high frequency of large-magnitude landslides and the subsequent destruction, the whole area remains understudied. Using the Limit Equilibrium Method, this study explores the slope failure along the Hunza River (HR), Village Humarri Nagar District Upper Hunza Gilgit Baltistan, Pakistan (LEM). Using Slide Rocscience programmer, the slope was fully studied for geological conditions, slope geometry, soil strength parameters, and FOS determination. Soil samples from the slope were gathered for analysis of geotechnical properties, and the slope's geometry was also analysed during the excursion. Moisture content (w) 1%, specific gravity (Gs) 2.64, unit weight (r) 19kN/m3, angle of internal friction (AIF) 30 and cohesion (c) 69 kPa are the strength parameters of the soil sample. The Humarri active landslide soil was classed as sandy silt with the group sign ML by the Unified Classification System (UCS). In Slide Rocscience programme, the FOS of the slope was calculated using LEM with the assumption of ordinary (O), Janbu (J), and Bishop (B) techniques. A set of instances were used to calculate the influence of Pore Water Pressure (PWP), Unit Weight, Cohesion, Angle of Internal Friction, and Overburden on FOS. FOS increases when cohesiveness and angle of internal friction rise; yet, FOS increases as unit weight and overburden of overlying materials grow. Furthermore, while PWP has some good effects, increasing it causes a significant decline in FOS. Because every FOS is larger than 1, the Humarri active landslide is judged to be stable in its current form based on available strength metrics and simulated slide conscience results.
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Wang, Jia, Wenwen Dong, Wenzhao Yu, Chengcheng Zhang e Honghu Zhu. "Numerical and Experimental Investigation of Slope Deformation under Stepped Excavation Equipped with Fiber Optic Sensors". Photonics 10, n. 6 (17 giugno 2023): 692. http://dx.doi.org/10.3390/photonics10060692.
Testo completoAbstract (sommario):
The real-time evaluation of slope stability is a crucial technical issue in foundation excavation and slope construction. However, conventional monitoring methods often fall short of achieving real-time and accurate measurements, which poses challenges to the timely assessment of slope stability. To address this problem, laboratory tests and numerical simulations were jointly used to evaluate slope stability in this paper. In numerical simulations, the finite element method (FEM) results clearly illustrate the distribution and evolution of internal strain during slope excavation, and the limit equilibrium method (LEM) calculates changes in the safety factor. In laboratory tests, the fiber Bragg grating (FBG) sensing technology was employed to monitor the internal strain of the slope in real time. The distribution characteristics of the slope internal strain field under the condition of stepped excavation were analyzed, and the feasibility of strain-based evaluation of slope stability was discussed. The measurements with FBG sensing technology agree well with the numerical simulation results, indicating that FBG can effectively monitor soil strain information. Of great significance is that the maximum horizontal strain of the slope is closely related to the safety factor and can be used to evaluate slope stability. Notably, the horizontal soil strain of the slope provides insight into both the formation and evolution of the critical sliding surface during excavation. The combination of numerical simulation and intelligent monitoring technology based on FBG proposed in this paper provides a reference for capturing strain information inside the slope and realizing real-time assessment and critical warning of slope stability.
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Ma, Li, Kemin Li, Shuangshuang Xiao, Xiaohua Ding e Sydney Chinyanta. "Research on Effects of Blast Casting Vibration and Vibration Absorption of Presplitting Blasting in Open Cast Mine". Shock and Vibration 2016 (2016): 1–9. http://dx.doi.org/10.1155/2016/4091732.
Testo completoAbstract (sommario):
The impact energy produced by blast casting is able to break and cast rocks, yet the strong vibration effects caused at the same time would threaten the safety of mines. Based on the theory of Janbu’s Limit Equilibrium Method (LEM), pseudo-static method has been incorporated to analyze the influence of dynamic loads of blasting on slope stability. The horizontal loads produced by blast vibrations cause an increase in sliding forces, and this leads to a lower slope stability coefficient. When the tensile stresses of the two adjacent blast holes are greater than the tensile strength of rock mass, the radical oriented cracks are formed, which is the precondition for the formation of presplit face. Thus, the formula for calculating the blast hole spacing of presplit blasting can be obtained. Based on the analysis of the principles of vibration tester and vibration pick-up in detecting blast vibrations, a detection scheme of blast vibration is worked out by taking the blast area with precrack rear and non-precrack side of the detection object. The detection and research results of blast vibration show that presplit blasting can reduce the attenuation coefficient of stress wave by half, and the vibration absorption ratio could reach 50.2%; the impact of dynamic loads on the end-wall slope stability coefficient is 1.98%, which proves that presplit blasting plays an important role in shock absorption of blast casting.
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Esterhuyse, J. C., e D. F. Malan. "Simulating pillar reinforcement using a displacement discontinuity boundary element code". Journal of the Southern African Institute of Mining and Metallurgy 123, n. 5 (13 luglio 2023): 211–21. http://dx.doi.org/10.17159/2411-9717/2450/2023.
Testo completoAbstract (sommario):
In this study we explore the use of a novel numerical modelling approach to study the effect of pillar reinforcement on pillar stability. Case studies in the literature indicate that tendons, strapping of the pillars, and shotcrete or thin spray-on liners are commonly used to reinforce pillars. No clear methodology exists to select the type of support or to design the capacity of the support required, however. This has led to ongoing collapses in some mines in spite of heavy support being used to reinforce unstable pillars. A limit equilibrium model with confinement on the edge of the pillar was used to simulate the interaction of the support with the failing pillar. The model correctly predicts that an increase in confinement will lead to a decrease in the extent of pillar failure. As the displacement discontinuity boundary element method allows for the efficient solution of large-scale bord-and-pillar layouts, the effect of pillar confinement can now be studied on a mine-wide scale. Accurate calibration of the limit equilibrium model is, however, required before this method can be used for the design of effective pillar support.
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Chen, Sheng, Yang Hao, Wencai Zhang, Ying Sun e Xue Liu. "Comprehensive Analysis of the Failure Potential of a Motorway Landslide in Dabu County, China". Water 15, n. 14 (24 luglio 2023): 2675. http://dx.doi.org/10.3390/w15142675.
Testo completoAbstract (sommario):
Because the failure potential of a landslide is difficult to assess, a motorway landslide that has obviously deformed was used as a case study in this research. Several multi-integrated geotechniques, including field investigation, drilling, electrical resistivity tomography (ERT), stability analysis, and numerical simulations, were used to achieve this goal. Field investigation with drilling was used to roughly determine the failure potential mass boundary and the material composition ERT technique was further used to distinguish the structure and composition of underground materials; the results agreed well with the field investigation, as well as the drilling data in the lithology judgement. The above investigations also showed the failure potential mass is in a slow sliding state and the slip surface roughly follows the contact zone between the upper soil and bedrock. Next, stability analysis based on the limit equilibrium method (LEM) was used to judge the current stability status of the slope, and its factor of safety (FOS) was 1.2 under the natural condition, 1.05 under the earthquake condition, and 1.15 under the rainfall condition. Based on the assessed potential slip surface and digital elevation data, a three-dimensional smoothed particle hydrodynamics (SPH) model was used to simulate the failure potential process. The dynamic information of the run-out behavior, including velocity, movement distance, and frictional energy, can be obtained, which is useful for hazard prediction.
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Mohamed, Tarig, e Anuar Kasa. "Application of Fuzzy Set Theory to Evaluate the Stability of Slopes". Applied Mechanics and Materials 580-583 (luglio 2014): 566–71. http://dx.doi.org/10.4028/www.scientific.net/amm.580-583.566.
Testo completoAbstract (sommario):
An artificial intelligence tools, Adaptive Neuro Fuzzy Inference System (ANFIS), was used in this study to predict the stability of slopes. Data used in this study were 300 various designs of slope. Those designs were created by using Slope/W which calculated factors of safety using various limit equilibrium methods (LEM) such as Bishop, Spencer and Morgenstern-Price. The input parameters consisted of height of slope, H (1–10 m), unit weight of slope material, γ (15-22 kN/m3), angle of slope, θ (11.31°-78.69°), coefficient of cohesion, c (0-50 kN/m2) and internal angle of friction, (20°- 40°) and the output parameter is the factor of safety. To build the fuzzy inference system, 243 rules were used at 60 epochs. The number of membership function for the any input was three and the type of membership function for output was linear. ANFIS obtained regression square (R2) of one for Bishop, one for Janbu, one for Morgenstern-Price and one for Ordinary. The result proved that ANFIS may possibly predict the safety factor with good precision and nearly to the target data.
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Lee, Youn-Kyou, e S. Pietruszczak. "A New Discrete Form of Hoek–Brown Criterion and Its Application to Limit Equilibrium Analysis of Rock Slope Stability". Sustainability 14, n. 19 (25 settembre 2022): 12113. http://dx.doi.org/10.3390/su141912113.
Testo completoAbstract (sommario):
The generalized Hoek–Brown criterion (GHB) is recognized as one of the standard failure criteria in rock engineering and its validity extends to a wide range of rock mass quality. A drawback of this criterion is the difficulty of transforming it into an explicit form defining the Mohr failure envelope when its strength parameter a is not equal to 0.5. The information on the functional form of the Mohr envelope for the full range of rock mass conditions enables the implementation of classical engineering approaches, such as the limit equilibrium method and limit analysis, in the framework of the GHB criterion. Knowing that for a≠0.5 the exact closed-form representation of the Mohr envelope is not feasible, an alternative is to express it in an approximate analytical form. The main purpose of this study is to propose a new improved method to define an approximate Mohr envelope of the GHB criterion that is much more accurate compared with the recently published approximations. The idea behind the formulation is to expand the Balmer’s equation, which defines the relationship between the normal stress and minor principal stress at failure, by invoking the finite Taylor series centered at the known solution for a=0.5. The formulation is then completed by substituting this solution into another Balmer’s equation, defining the relationship between the shear strength and the minor principal stress. The Taylor polynomial approximations of up to third degree are considered in the formulation. The accuracy of the shear strength prediction is shown to be much better than that of the approximate formula of Lee and Pietruszczak proposed in 2021. An illustrative example of limit equilibrium analysis of rock slope stability, incorporating the new approximate expression for the Mohr envelope, is provided. The analysis incorporates a modified version of the Bishop approach, which is simpler and more rigorous than the original nonlinear expression. The study confirms that the new approximate representation of the Mohr failure envelope can facilitate the application of the GHB criterion to a range of practical rock engineering calculations.
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Xu, Li-Wei, e Yu-Jian Lin. "Experimental Study on the Active Earth Pressure of Narrow Cohesionless Backfills against Rigid Retaining Wall under the Translation Mode". Advances in Civil Engineering 2020 (12 novembre 2020): 1–9. http://dx.doi.org/10.1155/2020/8889749.
Testo completoAbstract (sommario):
In engineering, the new retaining walls are often constructed near the existing structure owing to the space limitation. The backfill behind the retaining wall is narrow, which causes an overestimation in the active earth pressure by using Coulomb’s earth pressure theory. In previous studies, experimental observations for the failure modes of narrow backfills are still rare. To confirm the failure mode of the narrow backfill, the experimental method and the geotechnical particle image velocimetry method are employed to observe the active failure process of the cohesionless narrow backfill with various widths under the translation mode. The experimental results revealed that the decrease in the length of the backfill width led to the increase in the inclined angle of the sliding surface. When the backfill width was sufficiently small, the sliding surface developed from the wall toe to another wall face, and then another sliding surface occurred as a reflection. In addition, the active earth pressure of the narrow backfill is significantly smaller than that calculated using Coulomb’s method. The active failure calculation models are established based on the experimental results. The active earth pressure of the narrow cohesionless backfill under the translation mode is derived by using the limit equilibrium methods. The proposed method was validated by comparing with the previous method and the experimental data.
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Dai, Xiaoru, Barbara Schneider-Muntau, Julia Krenn, Christian Zangerl e Wolfgang Fellin. "Mechanisms for the Formation of an Exceptionally Gently Inclined Basal Shear Zone of a Landslide in Glacial Sediments—The Ludoialm Case Study". Applied Sciences 13, n. 11 (5 giugno 2023): 6837. http://dx.doi.org/10.3390/app13116837.
Testo completoAbstract (sommario):
The Ludoialm landslide, which is located in the municipality of Münster in Tyrol, Austria, represents a large-scale translational landslide in glacial soil sediments characterised by an exceptionally low inclined basal shear zone of only 12°. Although a temporal coincidence between meteorological events and slope displacement is obvious, the hydromechanical coupled processes responsible for the initial landslide formation and the ongoing movement characteristics have not yet been identified. This article provides a comprehensive analysis of the predisposition factors and the initial failure mechanism of this landslide from geological and geotechnical perspectives. We use a prefailure geometry of the cross section to simulate the initial slope failure process by a limit equilibrium analysis (LEA), a strength-reduction finite element method (SRFEM), and a finite element limit analysis (FELA). The shape and location of the computationally obtained basal sliding zone compare well with the geologically assumed one. Based on the computational study, it turns out that a high groundwater table probably caused by snow melting in combination with different permeabilities for the different layers is needed for the formation of the exceptionally low inclined basal shear zone. This paper presents the failure mechanism of the Ludoialm landslide and discusses the role of the shear band propagation in the process of slope destabilization.
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Latt, Jonas, Christophe Coreixas, Joël Beny e Andrea Parmigiani. "Efficient supersonic flow simulations using lattice Boltzmann methods based on numerical equilibria". Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 378, n. 2175 (22 giugno 2020): 20190559. http://dx.doi.org/10.1098/rsta.2019.0559.
Testo completoAbstract (sommario):
A double-distribution-function based lattice Boltzmann method (DDF-LBM) is proposed for the simulation of polyatomic gases in the supersonic regime. The model relies on a numerical equilibrium that has been extensively used by discrete velocity methods since the late 1990s. Here, it is extended to reproduce an arbitrary number of moments of the Maxwell–Boltzmann distribution. These extensions to the standard 5-constraint (mass, momentum and energy) approach lead to the correct simulation of thermal, compressible flows with only 39 discrete velocities in 3D. The stability of this BGK-LBM is reinforced by relying on Knudsen-number-dependent relaxation times that are computed analytically. Hence, high Reynolds-number, supersonic flows can be simulated in an efficient and elegant manner. While the 1D Riemann problem shows the ability of the proposed approach to handle discontinuities in the zero-viscosity limit, the simulation of the supersonic flow past a NACA0012 aerofoil confirms the excellent behaviour of this model in a low-viscosity and supersonic regime. The flow past a sphere is further simulated to investigate the 3D behaviour of our model in the low-viscosity supersonic regime. The proposed model is shown to be substantially more efficient than the previous 5-moment D3Q343 DDF-LBM for both CPU and GPU architectures. It then opens up a whole new world of compressible flow applications that can be realistically tackled with a purely LB approach. This article is part of the theme issue ‘Fluid dynamics, soft matter and complex systems: recent results and new methods’.
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Bardanis, Michael, Sofia Grifiza e Marianna Feuillas. "A simplified approach to estimating the evolution of residual shear strength of unsaturated soils with suction". E3S Web of Conferences 382 (2023): 04002. http://dx.doi.org/10.1051/e3sconf/202338204002.
Testo completoAbstract (sommario):
Several researchers have investigated the effect of suction and partial saturation on the angle of residual shear strength. Most of these investigations involve the adoption and application of a method of controlling suction on the ring shear apparatus and performing ring shear tests on the same soil for various values of suction. Methods adopted include both the axis translation technique for control of suction over the range 50-1500 kPa and the saturated salt solutions method for control of suction in the range of several MPa. The general picture from these investigations is that the residual shear strength failure envelope remains linear but corresponding to higher values of the angle of residual shearing resistance for constant suction; this value increasing with increasing suction. The paper presents an attempt to normalise values of measured angle of residual shearing resistance for various suction values with the angle of residual shear strength of the corresponding fully saturated soil. This normalisation verified the linear increase of the ratio tanφres(s)/tanφres(s=0) with suction. This linear increase allows for estimation of the evolution of tanφres(s) with suction if φres(s) for one specific suction can be measured. This observation led to the measurement of tanφres(s) of clayey soils in conventional ring shear apparatus without suction control, simply by removing water from the shear box while shearing continues and measuring shear strength until its stabilisation, taking place after the specimen in the shear box came to equilibrium with prevailing laboratory atmospheric conditions. Using the chilled mirror hygrometer to measure equilibrium suction after ring shear completion indicated that equilibrium suction due to laboratory atmospheric conditions is practically constant over the time needed for a single test on one soil. This observation along with the previous observation on the linear increase of the ratio tanφres(s)/tanφres(s=0) with suction, makes valid the estimation of evolution of residual shear strength of unsaturated soils with suction using only a conventional ring shear apparatus and a chilled mirror hygrometer. The paper concludes by outlining the approach, presenting measurements and a relation obtained between tanφres(s)/tanφres(s=0), suction and liquid limit.
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Sarcina, Lucia, Giuseppe Felice Mangiatordi, Fabrizio Torricelli, Paolo Bollella, Zahra Gounani, Ronald Österbacka, Eleonora Macchia e Luisa Torsi. "Surface Plasmon Resonance Assay for Label-Free and Selective Detection of HIV-1 p24 Protein". Biosensors 11, n. 6 (3 giugno 2021): 180. http://dx.doi.org/10.3390/bios11060180.
Testo completoAbstract (sommario):
The early detection of the human immunodeficiency virus (HIV) is of paramount importance to achieve efficient therapeutic treatment and limit the disease spreading. In this perspective, the assessment of biosensing assay for the HIV-1 p24 capsid protein plays a pivotal role in the timely and selective detection of HIV infections. In this study, multi-parameter-SPR has been used to develop a reliable and label-free detection method for HIV-1 p24 protein. Remarkably, both physical and chemical immobilization of mouse monoclonal antibodies against HIV-1 p24 on the SPR gold detecting surface have been characterized for the first time. The two immobilization techniques returned a capturing antibody surface coverage as high as (7.5 ± 0.3) × 1011 molecule/cm2 and (2.4 ± 0.6) × 1011 molecule/cm2, respectively. However, the covalent binding of the capturing antibodies through a mixed self-assembled monolayer (SAM) of alkanethiols led to a doubling of the p24 binding signal. Moreover, from the modeling of the dose-response curve, an equilibrium dissociation constant KD of 5.30 × 10−9 M was computed for the assay performed on the SAM modified surface compared to a much larger KD of 7.46 × 10−5 M extracted for the physisorbed antibodies. The chemically modified system was also characterized in terms of sensitivity and selectivity, reaching a limit of detection of (4.1 ± 0.5) nM and an unprecedented selectivity ratio of 0.02.
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Theocharis, Alexandros, Ioannis Zevgolis e Nikolaos Koukouzas. "Numerical analysis of rainfall effects on the slope stability of open pit coal mines". E3S Web of Conferences 382 (2023): 13006. http://dx.doi.org/10.1051/e3sconf/202338213006.
Testo completoAbstract (sommario):
As the world transitions away from coal, vast areas of closed coal mines and waste dumps must be appropriately reclaimed. One critical element for these areas’ safety is slope stability, given the massive slopes of these mines and dumps. This work examines the effect of extreme rainfall on coal mines’ slopestability by incorporating unsaturated soil mechanics principles in a practical way. Past extreme rainfall events recorded for a Greek lignite mining area were used, and climate projections concluded that this intensity is not expected to change. Then, rainfall infiltration was simulated using the Finite Element Method; a typical slope was employed concerning a lignite mining excavation of 200m height and 14° inclination on fine-grained soils. Finally, the stability was calculated using the Limit Equilibrium Method. Rainfall infiltration caused the Safety Factor to decrease, leading to failure. The groundwater rose at theslope’s face from the slope’s toe upwards and led to the development of a smaller and more local than the initial (before rainfall) sliding surface with a lower Safety Factor. Although this is a smaller surface than the initial one, it is still more than 50m high, proposing a significant hazard with severe consequences for the area.
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Saksono, Rama Tri, I. Gde Budi Indrawan e Wahyu Wilopo. "Engineering Geology and Slope Stability of West Pit Coal Mine of PT. Tawabu Mineral Resource, East Kalimantan, Indonesia". Journal of Applied Geology 7, n. 2 (31 dicembre 2022): 83. http://dx.doi.org/10.22146/jag.76532.
Testo completoAbstract (sommario):
The research area was located in the west pit of the open pit coal mine of PT. Tawabu Mineral Resource (TMR) which is located in Bengalon District, East Kutai Regency, East Kalimantan Province, Indonesia. The research was driven by several landslides that occurred in the research area, but the engineering geological conditions and stability of the remaining slopes have not been evaluated. The objectives of this study were to better understand the engineering geological conditions and stability of the research area. The engineering geological conditions (i.e., geomorphology, rock and soil, geological structure, and groundwater conditions) were evaluated by photogrametric analyses, field observations, and analyses of borehole logs and laboratory test results. The slope stability analyses were firstly carried out by conducting back stability analyses of failed slope on the northern lowwall slope segment. The shear strength parameters obtained from the back analyses were then used for forward stability analyses of the remaining 10 lowwall and highwall slopes. The slope stability analyses involved deterministic and probabilistic analyses, under static and dynamic using the limit equilibrium method (LEM). The results showed that the research area and the surrounding consisted of two geomorphological units, namely the alluvial plain and structural hills. Rocks in the study area consisted of claystone, sandstone, and coal with a general layer strike direction of N59°E – N63°E with a dip of 19°-26°. These rocks were grouped into two lithological units, namely the alternating of claystone and sandstone unit and alternating of sandstone and claystone unit. The geological structures were identified on the highwall, from west to east namely major sinistral shear fault with a relative direction of NNE-SSW, two minor sinistral shear faults with a relative direction of NE-SW, and a major dextral shear fault with a relative direction of NW-SE. These geological structures were interpreted as being formed by the folding process. The groundwater level was estimated at a level of -45 m to 20 m. The slope stability analyses showed that only the East HW-4 slope, which was located on the east highwall, was unstable. It is recommended to optimize the slope by either lowering the groundwater elevation by 4 m from the actual level or by reducing the angle the overall slope to 31°.