scholarly journals Seismic Analysis of a Soil Slope to Develop Correlations for Factor of Safety Considering Horizontal and Vertical Seismic Coefficients

2020 ◽  
Vol 495 ◽  
pp. 012036
Author(s):  
Muhammad Israr Khan ◽  
Shuhong Wang
Keyword(s):  
Factor Of Safety ◽  
Seismic Analysis ◽  
Soil Slope

scholarly journals SEISMIC ANALYSIS OF A SOIL SLOPE TO DEVELOP CORRELATIONS FOR FACTOR OF SAFETY CONSIDERING HORIZONTAL AND VERTICAL SEISMIC COEFFICIENTS

2020 ◽  
Vol 4 (2) ◽  
pp. 27-30
Author(s):  
Muhammad Israr Khan ◽  
Shuhong Wang
Keyword(s):  
Slope Stability ◽  
Factor Of Safety ◽  
Seismic Analysis ◽  
Soil Slope ◽  
Seismic Coefficient ◽  
Soil Slopes ◽  
Slope Design

Seismic analysis of soil slopes is required to get safe value for slope design. Especially in earthquake zones. Normally a variation in factor of safety values is observed in normal analysis of a slope where seismic coefficients are kept zero as compare to seismic analysis where seismic coefficients are considered in the analysis. In this research, seismic horizontal coefficients are used to find the factors of safety. Correlations are developed between factor of safety values and seismic coefficients. The correlation can be used to find the factor of safety in any slope stability project for a homogenous slope. The outcome of this work are the correlations. These correlations can be used to find the factor of safety values considering horizontal seismic coefficient, vertical seismic coefficient and both.

scholarly journals Numerical Analysis of Soil Slope Stabilization by Soil Nailing Technique

2019 ◽  
Vol 9 (4) ◽  
pp. 4469-4473
Author(s):  
D. A. Mangnejo ◽  
S. J. Oad ◽  
S. A. Kalhoro ◽  
S. Ahmed ◽  
F. H. Laghari ◽  
...  
Keyword(s):  
Factor Of Safety ◽  
Slope Failure ◽  
Limit Equilibrium ◽  
Slope Instability ◽  
Soil Nailing ◽  
Soil Slope ◽  
Prevention Measures ◽  
Soil Nail ◽  
Soil Shear Strength ◽  
Nail Diameter

Slope instability may be a result of change in stress conditions, rise in groundwater table and rainfall. Similarly, many slopes that have been stable for several years can abruptly fail due to changes in geometry, weak soil shear strength or as the effect of an external force. Debris flows (i.e. slope failures) take place without any warning and can have devastating results. So, it is vital to understand the slope failure mechanism and adopt safety prevention measures. Soil nailing is one of the widely used stabilization techniques for soil slopes. In this study, soil nail technique is proposed to upgrade the existing slope in clay. A parametric study was conducted to understand the effects of different nail diameter (i.e. 25mm and 40mm) and nail inclination (i.e. 200, 250, 300, 350 and 400) on slope stability. Morgenstern-Price (i.e. limit equilibrium) method was used to determine the factor of safety of the slope. It was found that the factor of safety of the existing slope improved significantly with three rows of 40mm diameter nail at an inclination of 400.

Seismic analysis of nailed soil slope considering interface effects

2017 ◽  
Vol 100 ◽  
pp. 480-491 ◽  
Author(s):  
Dhanaji Chavan ◽  
Goutam Mondal ◽  
Amit Prashant
Keyword(s):  
Seismic Analysis ◽  
Soil Slope ◽  
Interface Effects

scholarly journals Failure Mechanism and Factor of Safety for Spatially Variable Undrained Soil Slope

2019 ◽  
Vol 2019 ◽  
pp. 1-17 ◽  
Author(s):  
Liang Li ◽  
Xuesong Chu
Keyword(s):  
Random Field ◽  
Failure Mechanism ◽  
Factor Of Safety ◽  
Limit Equilibrium ◽  
Vertical Direction ◽  
Failure Surface ◽  
Cohesive Soil ◽  
Soil Slope ◽  
The Stability ◽  
Undrained Soil

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.

Simplified Bishop Method Homogeneous Soil Slope Stability Analysis Based on the C# Language

2014 ◽  
Vol 580-583 ◽  
pp. 291-295
Author(s):  
Hai Bing Wei ◽  
Qian Zhang ◽  
Jun Hai Zhao
Keyword(s):  
Factor Of Safety ◽  
Slip Surface ◽  
Soil Slope ◽  
Critical Slip Surface ◽  
C Language ◽  
User Input ◽  
Fast Speed ◽  
Basic Parameters ◽  
Homogeneous Soil ◽  
Good Visibility

A computer program was compiled based on the C# language of Microsoft Visual Studio 2008 and the principle of simplified Bishop method. The program will calculate the minimum factor of safety, and automatically draw the two-dimensional (2-D) critical slip surface after user input the basic parameters. Through testing a lot of examples, the program has good stability, high precision, fast speed and good visibility.

scholarly journals Three-dimensional stability analysis of an urban slope located in João Monlevade, Brazil

2019 ◽  
Vol 8 (11) ◽  
pp. e168111449
Author(s):  
Fernanda Cristina Pereira ◽  
Flavia Laís Dias Oliveira ◽  
Laís Emily de Assis ◽  
Tatiana Barreto dos Santos
Keyword(s):  
Stability Analysis ◽  
Slope Stability ◽  
Dimensional Stability ◽  
Factor Of Safety ◽  
Three Dimensional ◽  
Friction Angle ◽  
City Council ◽  
Residual Soil ◽  
Soil Slope ◽  
Clayey Silt

Geotechnical stability analysis of slopes is an important tool for decision making in civil projects.  Use of three-dimensional software for analysis of soil slope stability has increased in recent years. Rocscience Inc. created Slide3 software in 2017. Slide3 is a software that allows geotechnical engineers to calculate the factor of safety of complex 3D slope stability geometries that 2D models cannot fully simulate. In this context, this paper presents a three-dimensional stability analysis of a slope located in an urban area at city of João Monlevade, Minas Gerais, Brazil. The slope was selected due to the instability history in rainfall periods. Topography of the area was provided by the city council. Young and mature residual soils were identified in the studied slope. Young residual soil was physically classified as clay without gravels and presents in natura values of cohesion and friction angle, equal to 32 KPa and 23.97º, respectively. Mature residual soil was physically classified as clayey silt without gravels and presents in natura values of cohesion and friction angle, equal to 19 KPa and 23.30º, respectively. The factor of safety of the soil slope was equal 0.977, considering the slope saturated. The factor of safety of the drained slope was equal to 1.415. Generalized limit equilibrium (GLE) method was used in this equilibrium-limit analysis.  The results stability analysis of the slope was coherent, once previous instability occurs in a period that was identified above average rainfall.

scholarly journals Slip surface in narrow backfill behind retaining wall

2021 ◽  
Vol 331 ◽  
pp. 03012
Author(s):  
Abdul Hakam ◽  
Deni Irda Mazni
Keyword(s):  
Factor Of Safety ◽  
Slope Failure ◽  
Slip Surface ◽  
Retaining Wall ◽  
Soil Mass ◽  
Soil Slope ◽  
Soil Pressure ◽  
Earth Reinforcement ◽  
The Stability ◽  
Steep Slopes

For a particular area in Geotechnical engineering, a soil slope is defined as a surface of soil mass which is inclined. It the slope is unstable or has insufficient factor of safety, then it needs to be strengthened by a retaining wall or a particular earth reinforcement to ensue slope failure does not occur. It has long been known that the pattern of slip failure is classified into two main types: translation and rotation. Other patterns of slip failure can be approached within the two mentioned types above. The main purpose of this classification is to assist the engineers in the process of the the stability analysis in purpose to obtain the safety factor of the slope and the reinforcement system if any. For the retaining wall reinforcement analysis, the developed method is generally in the form of soil pressure behind the wall. The pressure due to the self weight of the soil is generated by assuming the backfill is long enough, so that the slip failure can be fully described according to the two main types above. Then in cases where the backfill behind the wall is quite narrow, the method should be corrected or modified. These narrow areas are often found on roads that are built on relatively steep slopes. In this paper, the form of the slip failure behind a narrow retaining wall is presented. The results of this study are very useful for developing analytical methods for retaining soils that are built in narrow areas due to location limitations.

scholarly journals Slope Stability Analysis to Correlate Shear Strength with Slope Angle and Shear Stress by Considering Saturated and Unsaturated Seismic Conditions

2021 ◽  
Vol 11 (10) ◽  
pp. 4568
Author(s):  
Muhammad Israr Khan ◽  
Shuhong Wang
Keyword(s):  
Shear Stress ◽  
Shear Strength ◽  
Stability Analysis ◽  
Slope Stability ◽  
Factor Of Safety ◽  
Slip Surface ◽  
Limit Equilibrium ◽  
Slope Angle ◽  
Slope Stability Analysis ◽  
Soil Slope

Assessment and analysis of soil slope stability is an important part of geotechnical engineering at all times. This paper examines the assessment of soil slope stability in fine-grained soils. The effect of change in shear strength (τ), shear stress (σ) and slope angle (β) on the factor of safety has been studied. It correlates shear strength with slope angle and shear stress by considering the horizontal seismic coefficients in both saturated and unsaturated conditions. The slope failure surface was considered a circular slip surface. Statistical package for social sciences (SPSS) and Slide, numerical modeling software and limit equilibrium slope stability analysis software, respectively, are used to find out the correlations between the three basic parameters. The slope angle varied from 70 to 88 degrees, which are the most critical values for slope angles, and a total of 200 analyses were performed. τ, β and σ are correlated, and the correlations are provided in the results section. The results indicate that the correlations developed between the parameters have a very close relationship. The applicability of the developed equations is above 99%. These correlations are applicable in any type of soil slope stability analysis, where the value of shear strength and factor of safety is required with the variation of slope angle and shear stress.

scholarly journals The Rise of Groundwater Due to Rainfall and the Control of Landslide by Zero-Energy Groundwater Withdrawal System

2018 ◽  
Vol 7 (2.29) ◽  
pp. 921 ◽  
Author(s):  
Shamsan Alsubal ◽  
Nasiman Sapari ◽  
Indra S.H. Harahap
Keyword(s):  
Slope Stability ◽  
Factor Of Safety ◽  
Slope Failure ◽  
Groundwater Table ◽  
Groundwater Withdrawal ◽  
Natural Soil ◽  
Soil Slope ◽  
Soil Permeability ◽  
Zero Energy ◽  
The Third

Slope failure is a common issue in tropical countries. The rise of groundwater table due to rainfall is one of the main triggering factors. There are several methods for slope stabilization such as soil nailing, retaining walls, cut and fill, vegetation and so on. Most of those methods are costly and we are in need for stabilizing methods that are more economical and easier to construct. This article introduces a new method for slope stability. This method is examined numerically and experimentally. It is represented in an automatic zero-energy groundwater withdrawal system to enhance slope stability. The system is validated in a pre-fabricated model to ensure that it works on natural soil slope. The numerical simulation is performed in Soilworks software with coupled seepage-slope stability analysis using finite element methods to check the safety factor with and without the system. The effectiveness of this method is investigated with various rainfall intensities and soil permeabilities. The results for slopes with the application of groundwater withdrawal system are compared with the results without the system. The results demonstrate the effectiveness of the proposed method in reducing groundwater table and enhancing slope stability. The factor of safety for the slope with high soil permeability drops from 1.312 before the rainfall to 1.292 and 0.93 after the third rainfall event for the slope with and without pumping groundwater respectively. For soil slope with moderate soil permeability, the factor of safety deteriorates from 1.314 to 1.157 at the end of the third day, while it remains stable with pumping groundwater. Matric suction is highly increased at the crest of the slope due to pumping. 

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