scholarly journals The effect of flood on slope stability along downstream riverbank of MuaraBangkahulu River, Bengkulu City, Indonesia

2021 ◽  
Vol 926 (1) ◽  
pp. 012004
Author(s):  
L Z Mase ◽  
K Amri ◽  
M Frisky ◽  
P W Anggraini ◽  
M N Fikri ◽  
...  
Keyword(s):  
Slope Stability ◽  
Water Level ◽  
River Water ◽  
Critical Condition ◽  
Environmental Effect ◽  
Factor Of Safety ◽  
Slope Failure ◽  
Critical Conditions ◽  
Maximum Discharge ◽  
Downstream Area

Abstract The flood which occurred due to the rainfall intensity in Bengkulu City of Indonesia could inundate the downstream area of MuaraBangkahulu River, especially TanjungAgung Sub-District. In 2019, a huge flood had occurred in Bengkulu City and triggered the environmental effect to riverbank in TanjungAgung. This environmental effect is a massive slope failure on downstream riverbank in TanjungAgung. This study is therefore conducted to analyze the slope stability in the area during the normal and the critical conditions. A slope stability analysis using finite element method is performed. First, the maximum discharge of MuaraBangkahulu River is estimated. Furthermore, slope stability analyses are conducted by considering the normal condition and the increase of river water level due to the maximum discharge (the critical condition). Mapping of factor of safety for riverbank slope and soil deformation is conducted. The results showed that slope along downstream riverbank of MuaraBangkahulu could undergo slope failure under both normal and critical condition. The results also showed that the factor of safety decreases due to the increase of river water level. The results of this study could be used by local government to consider slope countermeasure in the study area

SLOPE STABILITY AND DEFORMATION ANALYSIS UNDER DRAWDOWN CONDITIONS (CASE STUDY: RAMA 9 RESERVOIR)

2016 ◽  
Vol 78 (5-2) ◽  
Author(s):  
Werasak Raongjant ◽  
Meng Jing
Keyword(s):  
Slope Stability ◽  
Water Level ◽  
Factor Of Safety ◽  
Slope Failure ◽  
Deformation Analysis ◽  
Analysis Program ◽  
Element Analysis ◽  
Earth Slopes ◽  
Security Value

The Rapid drawdown condition is one of the most dangerous conditions for earth slopes. The change of water level in reservoir always causes a slope failure. This paper presents an investigation on the slope stability of the Rama 9 Reservoir under different drawdown conditions depending on the drawdown ratio, the drawdown rate and the loading conditions. Finite element analysis program PLAXIS 2D 2012 were applied to define the displacement and the factor of safety for slopes at selected positions. The results shown that, in the rapid drawdown condition for the drawdown ratio of 0.75, the factor of safety is 1.16.  In the slow drawdown condition for the drawdown ratio of 1.00, the factor of safety is 1.26. Both are less than the ratio of allowable security value of 1.3. For the Rama 9 Reservoir, the reduction of the water level should be controlled more carefully. 

scholarly journals Assessment of the Upstream Slope Stability of Darbandikhan Rockfill Dam during Drawdown

2021 ◽  
Vol 9 (1) ◽  
pp. 8-15
Author(s):  
Sirwan Gh. Salim ◽  
Krikar M. G. Noori
Keyword(s):  
Steady State ◽  
Numerical Analysis ◽  
Slope Stability ◽  
Water Level ◽  
Factor Of Safety ◽  
Computer Software ◽  
Loading Conditions ◽  
Upstream Slope ◽  
Rockfill Dam ◽  
The Stability

Earth and rockfill dams face a variety of loading conditions during lifetime. One of the most critical loading conditions is the rapid drawdown of water level after steady state conditions. Rapid drawdown may cause instability of upstream slope of the dam. The present work examines the stability of a rockfill dam under different drawdown rates in terms of factor of safety for the upstream slope of the dam. For this purpose, a computer software named GeoStudio 2012 SEEP/W and SLOPE/W has been used for the numerical analysis. The results showed that the drawdown rate has a significant effect on stability of rockfill dam in which increasing the drawdown rate from 1 m/day to 10 m/day decreases the stability of the dam by 33%. Based on the outcomes, for the studied case the drawdown rate (1 m/day) can be recommended.

Slope stability study of the 2001 Taipei National University of the Arts landslide

2020 ◽  
Author(s):  
Chien Liu ◽  
Cheng-Han Lin ◽  
Ching Hung
Keyword(s):  
Slope Stability ◽  
Junior High School ◽  
Factor Of Safety ◽  
Slope Failure ◽  
Limit Equilibrium ◽  
Equilibrium Analysis ◽  
Soil Parameters ◽  
Element Analysis ◽  
The Arts ◽  
National University

<p>Situated within a subtropical and mountainous region where frequent typhoons hit, rainfall-induced landslides have been a critical issue in Taiwan. On September 29, 2001, due to the torrential rainfall brought by the Typhoon Nari and Lekima, a downslope in Taipei National University of the Arts failed. The sliding source hit and severely damaged the Tao-Yuan junior high school. Before the 2001 Taipei National University of the Arts landslide, several landslides had already occurred in this landslide-prone region. In this study, a two-dimensional (2D) slope stability analysis, based on the limit equilibrium analysis (LEA), is conducted to analyze the 2001 Taipei National University of the Arts landslide. LEA has been the most popular and widely used technique given that it can estimate the factor of safety of a slope with some preliminary site investigation information. By comparing the failure surface and factor of safety (FOS) suggested in the post-disaster report [1], reasonable soil parameters, which are in an agreement with the experimental results [1], can be obtained through the study. The obtained soil parameters can later be applied to coupled transient unsaturated seepage-stress finite element analysis (FEA) [2] that will help practical engineers to understand the onset of failure in the future study.</p><p> </p><p>REFERENCE</p><ol><li>Taiwan Professional Geotechnical Engineers Association. (2001). National Taipei University of the Arts tennis court down slope failure reason identification and long-term remediation plan suggestion work report.</li> <li>Hung, C., Liu, C. H., & Chang, C. M. (2018). Numerical investigation of rainfall-induced landslide in mudstone using coupled finite and discrete element analysis. Geofluids, 2018.</li> </ol>

scholarly journals Slope stability analysis considering seepage and stress coupling under water level fluctuation

2021 ◽  
Vol 276 ◽  
pp. 01028
Author(s):  
Zhou YiLiang ◽  
Li Ming ◽  
Li ZiLong
Keyword(s):  
Slope Stability ◽  
Water Level ◽  
Factor Of Safety ◽  
Coupling Effect ◽  
Water Pressure ◽  
Water Level Fluctuation ◽  
Level Fluctuation ◽  
Reservoir Water ◽  
Reservoir Water Level ◽  
Stability Calculation

The reservoir water level fluctuation is an important factor inducing the reaction of pore-water pressure, seepage and at last resulting in instability and failure of the slope. A typical homogeneous slope is conducted as an example in this paper, the seepage and stress coupling effect is considered, and the slope stability calculation and analysis are carried out by using the finite element stress method. The results demonstrate that the factor of safety increases with the reservoir water level rises, and then gradually changes from decrease to stabilization. It should be noted that the factor of safety decreases slightly during the initial stage of water level rising at the speed of 0.2 m/d, which the slope will probably lose its stability. On the other, the factor of safety changes from decrease to increase along with the reservoir water level drawdown, and then gradually tends to stabilization. There is a minimum factor of safety when the water level is at about 1/4 of the slope height, and the minimum factor of safety decreases with increasing drawdown speed, just as the factor of safety decreases from 0.83 to 0.73 when the drawdown speed is increased from 0.20 m/d to 5.0 m/d.

scholarly journals Assessments of Geotechnical Condition of Landslide Sites and Slope Stability Analysis Using Limit Equilibrium Method in Goncha Siso Eneses Area, Northwestern Ethiopia

2020 ◽  
Author(s):  
Azemeraw Wubalem
Keyword(s):  
Land Use ◽  
Soil Moisture ◽  
Stability Analysis ◽  
Slope Stability ◽  
Factor Of Safety ◽  
Slope Failure ◽  
Limit Equilibrium ◽  
Limit Equilibrium Method ◽  
Slope Stability Analysis ◽  
Equilibrium Method

Abstract Goncha Siso Eneses area is located in northwestern Ethiopia where landslide incidence is active. The landslide incidence in the area resulted in the devastation of 233.1 hectares of cultivated and non-cultivated land, death of eight people, demolition of five houses, displaced 90 households, and 45 households are under risk. The slope failure in this area also caused tilting of the power line, tilting of two houses, cracking of three-houses floor, failed of bridge and blocking of streams as well as springs. The purpose of this research is to evaluate the cause, failure mechanism, landslide distribution, geotechnical condition of the site, slope stability analysis, and factor of safety determination. Soil sampling, laboratory test, terrain characteristics, groundwater-surface manifestation characterization, groundwater depth determination, slope stability analysis, and factor of safety calculation were the most important activities employed in this research work. Using disturbed and undisturbed soil samples of the selected slope section, Atterberg limit (liquid limit & plastic limit), natural soil moisture, unit weight, specific gravity, and shear strength parameters (cohesion & internal friction angle) test were carryout as ASTM standard. The most marginal factor of safety of the area is determined based on the general limit equilibrium method that encompasses different methods inside using slope/w in GeoStudio 2018 software package considering various groundwater conditions for all selected slope sections. The factor of safety for all selected slope sections of the various method under different groundwater conditions is less than one. Based on the finding of field observation and laboratory results, landslide types (rock/soil slides, rock/earth fall, debris/earth flow, & soil creeping) and landslide factors of the study area (slope angle, slope shape, slope modification, land use, groundwater, soil type, and rainfall) are determined. This research finds out that the soil has a great contribution to slope failure in the study area, besides the soil moisture and improper land use practice.

Predictive Simulation of Concurrent Debris Flow: How Slope Failure Locations Affect Predicted Damage

2020 ◽  
Author(s):  
Kazuki Yamanoi ◽  
Satoru Oishi ◽  
Kenji Kawaike ◽  
Hajime Nakagawa
Keyword(s):  
Standard Deviation ◽  
Debris Flow ◽  
Water Level ◽  
Slope Failure ◽  
Predictive Simulation ◽  
Relative Standard ◽  
Case Simulation ◽  
Failure Location ◽  
Downstream Area ◽  
Debris Flow Initiation

Predictive simulation of concurrent debris flow using only pre-disaster information has proven to be difficult as a result of problems in predicting the location of debris-flow initiation (i.e., slope failure). However, because catchment topography has concave characteristics, with all channels in a catchment joining each other as they flow downstream, it is possible to predict damage to downstream area using relatively inaccurate initiation points. Based on this, this paper presents methodologies employing debris-flow initiation points generated randomly using statistical slope failure prediction. A many-case simulation across numerous initiation points was performed to quantify the effect of slope-failure location in terms of deviations in the predicted water level and terrain deformation. It was found that the relative standard deviation diminished as the points approached the downstream area, indicating a location-based predictability effect.

scholarly journals Forecasting Factor of Safety of Slopes Stability Using Several Machine Learning Techniques

2021 ◽  
Author(s):  
Arsalan Mahmoodzadeh ◽  
Mokhtar Mohammadi
Keyword(s):  
Machine Learning ◽  
Slope Stability ◽  
Factor Of Safety ◽  
Slope Failure ◽  
Short Term Memory ◽  
Gaussian Process Regression ◽  
Machine Learning Techniques ◽  
Unit Weight ◽  
Support Vector ◽  
Effective Parameters

Abstract Because of the disasters associated with slope failure, the analysis and forecasting of slope stability for geotechnical engineers are crucial. In this work, in order to forecast the factor of safety (FOS) of the slopes, six machine learning (ML) techniques of Gaussian process regression (GPR), support vector regression (SVR), decision trees (DT), long-short term memory (LSTM), deep neural networks (DNN), and K-nearest neighbors (KNN) were performed. A total of 327 slope cases in Iran with various geometric and shear strength parameters analyzed by PLAXIS software to evaluate their FOS, were employed in the models. The K-fold (K=5) cross-validation (CV) method was applied to evaluate the performance of models’ prediction. Finally, all the models produced acceptable results and almost close to each other. However, the GPR model with R2 = 0.8139, RMSE = 0.160893, and MAPE = 7.209772%, was the most accurate model to predict slope stability. Also, the backward selection method was applied to evaluate the contribution of each parameter in the prediction problem. The results showed that all the features considered in this study have significant contributions to slope stability. However, features φ (friction angle) and γ (unit weight) were the most effective and least effective parameters on slope stability, respectively.

scholarly journals SLOPE STABILITY ANALYSIS FOR EARTH DAMS USING (GEO-SLOPE/W)

2018 ◽  
Vol 11 (1) ◽  
pp. 70-81
Author(s):  
Jasim M Abbas ◽  
Zainab Ali Mutiny
Keyword(s):  
Slope Stability ◽  
Water Level ◽  
Material Properties ◽  
Factor Of Safety ◽  
Limit Equilibrium ◽  
Earth Dams ◽  
Limit Equilibrium Methods ◽  
The Earth ◽  
Maximum Value ◽  
Upstream Part

The study of slope stability is important in the design and construction of the earth dams under influence of special states. Some factors affect on the slope stability for the earth dams such as change the water level in the reservoir, dam configuration, material properties..etc. In this study, the factor of safety of upstream slope stability for number of exist earth dams has been assessed. To achieve the objective of this study, Geo-SLOPE/W program that based on limit equilibrium methods was used. Taking into account the case of dry condition and gradually rise of water level in upstream part for these dams. It can be seems that the slope stability of the earth dams increased in case of dry condition. In addition, the slope stability increased when the water reach to maximum value.

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. 

scholarly journals Assessments of Geotechnical Condition of Landslide Sites and Slope Stability Analysis Using Limit Equilibrium Method around Gundwin Town Area, Northwestern Ethiopia

2020 ◽  
Author(s):  
Azemeraw Wubalem Azeze
Keyword(s):  
Land Use ◽  
Soil Moisture ◽  
Stability Analysis ◽  
Slope Stability ◽  
Factor Of Safety ◽  
Slope Failure ◽  
Limit Equilibrium ◽  
Limit Equilibrium Method ◽  
Slope Stability Analysis ◽  
Equilibrium Method

Abstract The study area is located in northwestern Ethiopia where landslide incidence is active. The landslide incidence in the area resulted in the devastation of 233.1 hectares cultivated and non-cultivated land, death of eight people, demolition of five houses, displaced 90 households, and 45 households are under risk. The slope failure in this area also caused tilting of the power line, tilting of two houses, cracking of three-houses floor, failed of bridge and blocking of streams as well as springs. The purpose of this research is to evaluate the cause, failure mechanism, landslide distribution, geotechnical condition of the site, slope stability analysis and factor of safety determination. Soil sampling, laboratory test, terrain characteristics, groundwater-surface manifestation characterization, groundwater depth determination, slope stability analysis and factor of safety calculation were the most important activities employed in this research work. Using disturbed and undisturbed soil samples of the selected slope section, Atterberg limit (liquid limit & plastic limit), natural soil moisture, unit weight, specific gravity, and shear strength parameters (cohesion & internal friction angle) test were carryout as ASTM standard. The most marginal factor of safety of the area is determined based on the general limit equilibrium method that encompasses different methods inside using slope/w in GeoStudio 2018 software package considering various groundwater conditions for all selected slope sections. The factor of safety for all selected slope sections of the various method under different groundwater conditions is less than one. Based on the finding of field observation and laboratory results, landslide types (rock/soil slides, rock/earth fall, debris/earth flow, & soil creeping) and landslide factors of the study area (slope angle, slope shape, slope modification, land use, groundwater, soil type, and rainfall) are determined. This research finds out that the soil has a great contribution to slope failure in the study area, besides the soil moisture and improper land use practice.

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