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 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 Investigation of the Role of Crown Crack in Cohesive Soil Slope and Its Effect on Slope Stability Based on Extended Finite Element Method

2021 ◽  
Author(s):  
Yiding Bao ◽  
Yuchao Li ◽  
Yansong Zhang ◽  
Jianhua Yan ◽  
Xin Zhou
Keyword(s):  
Slope Stability ◽  
Extended Finite Element Method ◽  
Slope Failure ◽  
Slip Surface ◽  
Natural Soil ◽  
Tension Zone ◽  
Soil Slope ◽  
Extended Finite Element ◽  
Soil Slopes

Abstract Tensile cracks in soil slopes, especially developing at the crown, have been increasingly recognized as the signal of slope metastability. In this paper, the role of crown cracks in natural soil slopes was investigated and their effect on stability was studied. A numerical slope model based on the extended finite element method (XFEM) simulating the tensile behavior of soil was used. Before the simulation, a numerical soil tensile test was applied to validate the use of XFEM on tensile behavior of soil. Slope failure was simulated by using strength reduction technique, which can determine the potential slip surface of slope. The simulation results show that the crown crack forms in natural soil slopes when the plastic zone starts penetrating, and therefore it is reasonable to consider the crown crack as the signal of slope metastability. A sensitivity analysis shows that cracks are at the position of the tension zone or very long can obviously affect the slope stability. The stress variation analysis from the initial deformation to slip surface penetration shows that the slope is at a state of compressive stress initially. When plastic zone starts to penetrate, the upper part of slope generates tension zone, but the extent of tension zone is limited until slope failure. This shows why tensile cracks are difficult to form and be stretched in the deep part of the slope. The application of XFEM on slope stability analysis can be used to assess the tensile strength of soil and predict slope failure disaster.

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. 

Temperature and Suction Effects on Slope Stability under Undrained Condition

2016 ◽  
Vol 858 ◽  
pp. 98-103 ◽  
Author(s):  
Anuchit Uchaipichat
Keyword(s):  
Elevated Temperature ◽  
Slope Stability ◽  
Unsaturated Soil ◽  
Factor Of Safety ◽  
Failure Surface ◽  
Matric Suction ◽  
Soil Parameters ◽  
Soil Slope ◽  
Simulation Results ◽  
Increasing Temperature

In this paper, the variation of safety factor of unsaturated soil slope with temperature and matric suction was simulated. The simulation was performed using modified ordinary method of slices for unsaturated soil slope including temperature and suction effects. The expression for factor of safety of unsaturated soil slope at elevated temperature under undrained condition was derived. The ranges of temperature and suction in simulation were 25 to 60 degree Celsius and 0 to 100 kPa, respectively. The simulation was performed using soil parameters presented in literature. The simulation results shows the variation in factor of safety of soils slope with matric suction and temperature. The factor of safety of soil slope with circular failure surface increased with increasing matric suction for all values of temperature but decreased with increasing temperature for all values of matric suction.

Slope Stability Analysis under the Condition of Seepage

2012 ◽  
Vol 204-208 ◽  
pp. 241-245
Author(s):  
Yang Jin
Keyword(s):  
Finite Element Method ◽  
Shear Strength ◽  
Slope Stability ◽  
Negative Impact ◽  
Strength Reduction ◽  
Soil Slope ◽  
Failure State ◽  
Calculation Results ◽  
The Stability ◽  
Shear Strength Reduction

The stability of soil slope under seepage is calculated and analyzed by using finite element method based on the technique of shear strength reduction. When the condition of seepage or not is considered respectively, the critical failure state of slopes and corresponding safety coefficients can be determined by the numerical analysis and calculation. Besides, through analyzing and comparing the calculation results, it shows that seepage has a negative impact on slope stability.

Soil Strength Reduction Method Induced by Variation of Water Content

2012 ◽  
Vol 170-173 ◽  
pp. 847-852
Author(s):  
Peng Ming Jiang ◽  
Zhong Lei Yan ◽  
Peng Li
Keyword(s):  
Slope Stability ◽  
Unsaturated Soil ◽  
Unsaturated Soils ◽  
Characteristic Curve ◽  
Strength Reduction ◽  
Actual State ◽  
Soil Slope ◽  
Simple Method ◽  
The Common ◽  
The Stability

As the complexity of unsaturated soil theory, and it must have a long test period when we study the unsaturated soils, so the conventional design analysis software does not provide such analysis, so we can imagine that such a slope stability analysis does not accurately reflect the actual state of the slope. Based on the known soil moisture content，this paper use the soil water characteristic curve and strength theory of unsaturated soil to calculate the strength reduction parameters of soil which can calculate the stability of the soil slope when using the common calculation method. It is noticeable that this method can be extended and applied if we establish regional databases for this simple method, and these databases can improve the accuracy of the calculation of slope stability.

Sign in / Sign up

Export Citation Format

Share Document