scholarly journals Slope Stability of an Earth Dam during Drawdown Conditions (KHASA-CHAI Dam) as a Case Study

2018 ◽  
Vol 7 (4.37) ◽  
pp. 17
Author(s):  
Adnan Jayed Zedan ◽  
Mariwan Ridha Faris ◽  
Ahmed Amer Abdulsattar
Keyword(s):  
Slope Stability ◽  
Factor Of Safety ◽  
Slip Surface ◽  
Earth Dam ◽  
Downstream Face ◽  
Upstream Slope ◽  
Maximum Water Level ◽  
Water Drawdown ◽  
Action Taking ◽  
Safe Condition

Aiming in this research was to have a clear view about the behavior of Khasa-Chai Dam during the draw down action taking into consideration the newly built of this dam which was filling during the time of this article, the upstream slope was investigated by taking drawdown of the water from the reservoir. This dam is consists of the zoned embankment with a total length of (2.36 km) with an upstream slope (1v:3h) and downstream slope (1v:2h). Slope stability was investigated during the drawdown of the water from the reservoir by considering the water in the reservoir to be at maximum water level and by taking two cases during the rapid and slow drawdown. SLOPE/W which is a sub program from Geo-Slope software was used in association with SEEP/W software to find the factor of safety of the upstream slip surface during the drawdown conditions. It was noticed from the drawdown conditions that the phreatic line falls almost at the same position for both cases. Also for both cases the factor of safety of the upstream slip surface falls above the value of (1.0) and that is mean the upstream slope is in a safe condition when the water drawdown. The exit gradient and the rate of flow at the downstream face decrease with time as the water in the reservoir drawdown which means the factor of safety against boiling increases with time.  

scholarly journals Failure of Zoned Earth Dam (An analysis of earth dam break)

2019 ◽  
Vol 27 (1) ◽  
pp. 344-353
Author(s):  
Abdul-Hassan K. Al-Shukur ◽  
Ranya Badea’ Mahmoud
Keyword(s):  
Water Level ◽  
Factor Of Safety ◽  
Limit Equilibrium ◽  
Water Flux ◽  
Dam Break ◽  
The Body ◽  
Earth Dam ◽  
Dam Failure ◽  
Maximum Water Level ◽  
Maximum Water

One of the most common type of embankment dam failure is the dam-break due to overtopping. In this study, the finite elements method has been used to analyze seepage and limit equilibrium method to study stability of the body of an earthfill dam during the flood condition. For this purpose, the software Geostudio 2012 is used through its subprograms SEEP/W and SLOPE/W. Al-Adhaim dam in Iraq has been chosen to analysis the 5 days of flood. It was found that the water flux of seepage during the flood reaches about 8.772*10-5. m3/sec when the water level 146.5 m at 2nd day. Seepage through the embankment at maximum water level increased by 55.1 % from maximum water level. It was concluded that the factor of safety against sliding in downstream side decrease with increasing water level and vice versa. It was also concluded that the deposits are getting more critical stability during the conditions of flood when the factor of safety value reaches 1.219 at 2nd day.

scholarly journals Slope Stability Analysis of Haditha Dam after Earthquake using Geo-Studio Software

2021 ◽  
Vol 39 (4A) ◽  
pp. 599-613
Author(s):  
Moammed K. Malik ◽  
Ibtisam R. Karim
Keyword(s):  
Slope Stability ◽  
Water Levels ◽  
Earth Dam ◽  
Maximum Water Level ◽  
Safe Side ◽  
Actual Design ◽  
Maximum Water ◽  
Normal Water ◽  
Middle West ◽  
Stability Limits

The current study is designed to analyze theslope stability of Haditha damwhich is an earth-fill dam constructed on the Euphrates River in the middle-west of Iraq. Finite element modeling was used in the present study to analyze the combined seepage and post-earthquake slope stability of Haditha earth dam. The maximum water level of a steady seepage case was considered to evaluate seepage. - Three different water levels (maximum, normal, and minimum) were applied, and nine different equilibrium slope stability limits were used to analyze the upstream and downstream slopes of the dam with three horizontal maximum accelerations.The input data given to the software are the dam geometry and its material properties with the earthquake records in the year2019.The dam was investigated by considering the water in the reservoir to be at maximum, minimum and normal water levels in its actual design. It was concluded that the dam is on the safe side in terms of stability even though the change in the earthquake's conditions in Iraq.

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.

scholarly journals Grouting design for slope stability of kedung uling earthfill dam

2018 ◽  
Vol 147 ◽  
pp. 07001
Author(s):  
Najib ◽  
Agus Setyawan ◽  
Dwiyanto Joko Suprapto
Keyword(s):  
Slope Stability ◽  
Laboratory Tests ◽  
Factor Of Safety ◽  
Field Investigation ◽  
National Standard ◽  
Standard Requirement ◽  
Central Java ◽  
Maximum Water Level ◽  
Stability Model ◽  
Maximum Water

Kedung Uling earthfill dam locates at Wonogiri Regency, Central Java, Indonesia. The dam encountered sliding and settlement at the embankment wall. To minimize sliding and settlement and to optimize the dam, both field investigation and laboratory tests have been proceeded for slope stability analysis and remedial embankment wall. Soil and rock investigation around the dam, which is followed by 10 core drillings, have been conducted. Laboratory tests such as direct shear and index properties have also been carried on. The results were further used for dam slope stability model using slide 6.0 and were used to analyzed factor of safety (FS) of Kedunguling dam. 10 conditions of dam were simulated and strengthening body of dam with grouting was designed. The results showed two conditions, which are condition of maximum water level with and without earthquake at downstream, were unsatisfy Indonesia National Standard (SNI) for building and infrastructure. These conditions can be managed by using grouting for increasing stabilization of embankment wall. By setting up grouting, factor of safety increases and meet the SNI standard requirement.

A method for locating critical slip surfaces in slope stability analysis

2001 ◽  
Vol 38 (2) ◽  
pp. 328-337 ◽  
Author(s):  
Da-Yong Zhu
Keyword(s):  
Stability Analysis ◽  
Slope Stability ◽  
Factor Of Safety ◽  
High Efficiency ◽  
Slip Surface ◽  
Numerical Procedure ◽  
Slope Stability Analysis ◽  
Case Examples ◽  
Slip Surfaces ◽  
Global And Local

This paper presents a new method for locating critical slip surfaces of general shapes in slope stability analysis. On the basis of the principle of optimality, along with the method of slices, a critical slip field (CSF) in a slope is postulated which consists of a family of slip surfaces having maximum values of unbalanced thrust forces at exit points on the slope face. A numerical procedure is developed for constructing the CSF. The critical slip surface having minimum factor of safety is included in the CSF. All the critical slip surfaces corresponding to all of the exit points are thus determined consecutively, resulting in a global critical slip field (GCSF) which exhibits both global and local slope stability. Comparisons with other methods are made which indicate the high efficiency and accuracy of the proposed approach. Applications of the proposed method to two case examples are given, the results of which demonstrate its applicability to practical engineering.Key words: slope, stability, analysis, factor of safety, critical slip field.

Experimental and numerical study of upstream slope stability in an earth dam reservoir under rapid drawdown conditions

2021 ◽  
Vol 21 (4) ◽  
pp. 248
Author(s):  
Mansour Pakmanesh ◽  
Seyed Habib Mousavi Jahromi ◽  
Amir Khosrojerdi ◽  
Hossein Hassanpour Darvishi ◽  
Hossein Babazadeh
Keyword(s):  
Slope Stability ◽  
Numerical Study ◽  
Earth Dam ◽  
Dam Reservoir ◽  
Upstream Slope

Genetic algorithm search for critical slip surface in multiple-wedge stability analysis

1999 ◽  
Vol 36 (2) ◽  
pp. 382-391 ◽  
Author(s):  
Anthony TC Goh
Keyword(s):  
Genetic Algorithm ◽  
Stability Analysis ◽  
Slope Stability ◽  
Factor Of Safety ◽  
Search Strategy ◽  
Slip Surface ◽  
Pattern Search ◽  
Optimization Techniques ◽  
Thin Layers ◽  
Critical Slip Surface

Most procedures for determining the critical slip surface in slope-stability analysis rely on traditional nonlinear optimization techniques. The main shortcoming of these techniques is the uncertainty as to robustness of the algorithms to locate the global minimum factor of safety rather than the local minimum factor of safety for complicated and nonhomogeneous geological subsoil conditions. This paper describes the incorporation of a genetic algorithm methodology for determining the critical slip surface in multiple-wedge stability analysis. This search strategy is becoming increasingly popular in engineering optimization problems because it has been shown in a wide variety of problems to be suitably robust for the search not to become trapped in local optima. Three examples are presented to demonstrate the effectiveness of the genetic algorithm approach. The search strategy was found to be sufficiently robust to handle layered soils with weak, thin layers, and as efficient and accurate as the conventional pattern search method.Key words: critical slip surface, factor of safety, genetic algorithms, optimization, slope stability, wedge analysis.

An efficient search method for finding the critical circular slip surface using the Monte Carlo technique

2001 ◽  
Vol 38 (5) ◽  
pp. 1081-1089 ◽  
Author(s):  
AI Husein Malkawi ◽  
W F Hassan ◽  
S K Sarma
Keyword(s):  
Monte Carlo ◽  
Stability Analysis ◽  
Slope Stability ◽  
Factor Of Safety ◽  
Global Minimum ◽  
Reliable Method ◽  
Slip Surface ◽  
Search Method ◽  
Monte Carlo Technique ◽  
Critical Slip Surface

Locating the critical slip surface and the associated minimum factor of safety are two complementary parts in a slope stability analysis. A large number of computer programs exist to solve slope stability problems. Most of these programs, however, have used inefficient and unreliable search procedures to locate the global minimum factor of safety. This paper presents an efficient and reliable method to determine the global minimum factor of safety coupled with a modified version of the Monte Carlo technique. Examples are presented to illustrate the reliability of the proposed method.Key words: factor of safety, method of search, critical slip surface, circular, global, Monte Carlo.

Influence of valley geometry on stability of an earth dam

2014 ◽  
Vol 51 (10) ◽  
pp. 1207-1217 ◽  
Author(s):  
Ashok K. Chugh
Keyword(s):  
Numerical Model ◽  
Continuum Mechanics ◽  
Factor Of Safety ◽  
Slip Surface ◽  
Three Dimensional ◽  
Valley Floor ◽  
Earth Dam ◽  
Two Dimensional ◽  
Crest Length ◽  
Practical Implications

Influence of valley geometry on stability of an earth dam is assessed in terms of its static slope stability. Numerical model results for an earth dam sited in a trapezoidal valley are presented for two combinations of dam crest length and valley floor width. In one combination, the valley floor width is held constant and the slope of valley walls is varied; in the second combination, the dam crest length is held constant and the slope of valley walls is varied. The results for the two combinations are not the same. The results presented are from three-dimensional (3-D) and two-dimensional (2-D) continuum-mechanics-based numerical analyses and are in terms of factor of safety (FoS) and associated slip surface. Significant results include: (i) influence of valley geometry on FoS is minimal when valley floor width exceeds about five times the dam height; and (ii) ratio of 3-D to 2-D FoS can be in the range of 1.03 to 1.30 depending on the valley geometry. Practical implications of the results are included.

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