scholarly journals The Evaluation of Failure Structure Condition with Plaxis Program on the Poso I Hydropower Barrage

2021 ◽  
Vol 930 (1) ◽  
pp. 012097
Author(s):  
L Prasetyorini ◽  
E N Cahya ◽  
R D Lufira
Keyword(s):  
Safety Factor ◽  
Water Pressure ◽  
Hydropower Station ◽  
Flood Level ◽  
Operating Level ◽  
Sliding Stability ◽  
Downstream Section ◽  
Empty Condition ◽  
Central Sulawesi ◽  
Minimum Operating

Abstract The Poso I Hydropower Station is located on the Poso River, at the downstream section of the Poso Lake in Central Sulawesi Province. At the weir site, the catchment area is 1906.30 km2, and the structures are designed for a 50 year return period. Flood discharge is 1456.50 m3/s, with the mean annual release being 127.85 m3/s. The total supply water level is 510.50m, and the minimum operating level is 506.00 m. The model uses an undistorted model with a scale of 1 to 60. The barrage needs to be reviewed for failure factors that are likely to occur similar to those used in potential failures in the construction of dams in general. The study was considered in three conditions: empty barrage condition, average level, and flood level. With the piping calculation method, the barrage used Lane and Bligh method. While the calculation of barrage sliding stability used Finite Element Method with Plaxis 2D program simulation got the safety factor at the empty condition and flood level. It is caused by water pressure at flood level conditions that influence barrage stability. Safety factor value exceeded permits made. The Poso I Hydropower Station was safe.

scholarly journals Beyond the implications of Grand Ethiopian Renaissance Dam filling policies

2021 ◽  
Vol 7 (3) ◽  
pp. 313-330
Author(s):  
Abay Yimere ◽  
◽  
Engdawork Assefa ◽  
Keyword(s):  
Time Series Data ◽  
Water Levels ◽  
Series Data ◽  
Future Climate Change ◽  
Policy Debate ◽  
International Treaty ◽  
Term Operation ◽  
Operating Level ◽  
Minimum Operating

<abstract> <p>The Grand Ethiopian Renaissance Dam (GERD) in Ethiopia and High Aswan Dam (HAD) in Egypt both operate on the Nile River, independent of a governing international treaty or agreement. As a result, the construction of the GERD, the Earth's eighth largest dam, ignited a furious debate among Ethiopia, Sudan, and Egypt on its filling policies and long-term operation. Ethiopia and Egypt's stance on the Nile River's water resources, combined with a nationalistic policy debate on the GERD's filling policies and long-term operation, has severely affected progress toward reaching agreeable terms before the first round of GERD filling was completed. These three countries continue to debate on the terms of agreement for the second round of GERD filling, scheduled to start by July 2021. We examined the GERD filling strategy for five- and six-year terms using time series data for the periods 1979–1987 and 1987–1992 to combine analyses for dry and wet seasons and investigate the potential impacts of filling the GERD above the downstream HAD using four HAD starting water levels. A model calibrated using MIKE Hydro results shows that during both five- and six-year terms of future GERD filling, Egypt would not need to invoke the HAD's minimum operating level. We pursued a narrative approach that appeals to both a technical and non-technical readership, and our results show the urgent need for cooperation at both policy and technical levels to mitigate and adapt to future climate change through the development of climate-proof agreements. Moreover, the results call for the riparian countries to move away from the current nationalistic policy debate approach and pursue a more cooperative, economically beneficial, and climate adaptive approach.</p> </abstract>

The Research of Pore Water Pressure Effect on the Slope Safety Factor Based on Flac

2012 ◽  
Vol 166-169 ◽  
pp. 1433-1436 ◽  
Author(s):  
Hai Bo Liu ◽  
Li Hua Zhang ◽  
Da Hao Lin
Keyword(s):  
Pore Water ◽  
Safety Factor ◽  
Pressure Effect ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Slope Safety

On the basis of the Australian Computer Society(ACADS)`s typical questions1(a),first, regardless of the slope in the case of pore water pressure, used FLAC procedure calculate the safety factor, the result was very close to the reference answer given by ACADS, we can see the accuracy of FLAC. Then, applied to the slope of different pore water pressure, obtained safety factor under corresponding conditions, then, we found that the pore water pressure had effect on the slope safety factor, but the influence are not same, when the pore water pressure less than a certain value, the influence are very small, but, when the pore water pressure exceeded this value, the influence became very large.

Security Control Method of Loading for Surcharge Preloading Based on the Stress Path

2011 ◽  
Vol 368-373 ◽  
pp. 2795-2803
Author(s):  
Heng Hu ◽  
Yan Li ◽  
Zhi Liang Dong ◽  
Yan Luo ◽  
Gong Xin Zhang
Keyword(s):  
Pore Water ◽  
Safety Factor ◽  
Control Method ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Stress Path ◽  
Excess Pore Water Pressure ◽  
Surcharge Preloading ◽  
Security Control ◽  
Excess Pore

All the time, security control method of loading is an important research part in the surcharge preloading, which is directly related to safety of the construction process. Starting from the stress path, discussing the variation of excess pore water pressure and relationship between stress path and security, and bringing forward the control method with a safety factor Fs based on the stress path. By measuring the change of excess pore water pressure, the control method with a safety factor Fs can reflect quantitatively the security status of soil and achieve the purpose of the process control, finally the security control method including the safety factor of loading and speed control is put forward to monitor construction safety. The safety factor of loading Fs is verified and back analyzed with the finite-element software, getting the correction factor from 0.90 to 1.20.

scholarly journals Simulation Parameter Selection and Steady Seepage Analysis of Binary Structure Slope

Water ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2747
Author(s):  
Xuhe Gao ◽  
Baocheng Cheng ◽  
Weiping Tian ◽  
Zhipei Zhang ◽  
Jiachun Li ◽  
...  
Keyword(s):  
Steady State ◽  
Safety Factor ◽  
Water Pressure ◽  
Soil Layer ◽  
Equivalent Strain ◽  
Extreme Value ◽  
Test Method ◽  
Seepage Analysis ◽  
Binary Structure ◽  
Slope Excavation

The selection of calculation parameters for slope excavation support design and the analysis of seepage stability is a significant challenge. This difficulty also hinders the development of slope support engineering. This study examined the right binary structure slope engineering of the K5 + 220–K5 + 770 section of the TJ1A mark of the Jiangkou-Weng’an Highway in Guizhou province. In this study, we propose and use the deep displacement monitoring data and p value test method to check the simulation parameters. Furthermore, the superposition calculation method for steady-state seepage analysis of slope geotechnical structure is proposed. A comparative analysis of the displacement, strain, stress, and safety factor of the slope after the application of pore water pressure was carried out for three slope conditions. The analysis showed that steady-state seepage has a significant effect on the displacement of the slope during the completion of excavation. As a result, a continuous distribution of strain arises on the slope along the interface between the potential sliding surface and the rock–soil layer, and then forms a continuous sliding zone. Additionally, steady-state seepage has a significant effect on the position of the displacement distribution during the initial support of the slope, leading to a significant increase in the extreme value of the shear outlet displacement of the potential slip surface of the slope and in the extreme value of equivalent strain. Finally, steady-state seepage reduces the displacement and equivalent strain upon construction of the secondary slope support. The steady-state seepage has a limited effect on the stress concentration, but reduces the safety factor calculated using the strength reduction method, in all three stages of slope excavation and support. This study enriches the analysis methods for determining the stability of a dual-structure slope during the rainy season, and provides new ideas for the safety and control of slope support projects.

Effect of Cushion Layers on Mechanical Characteristics of Spiral Case Structure in Hydropower Station

2013 ◽  
Vol 351-352 ◽  
pp. 897-900
Author(s):  
Bo Liu ◽  
Jian Hua Liu ◽  
Zhe Wang
Keyword(s):  
Mechanical Characteristics ◽  
Poisson Ratio ◽  
Water Pressure ◽  
Deformation Modulus ◽  
Hydropower Station ◽  
Finite Element Program ◽  
Load Bearing ◽  
Spiral Case ◽  
Element Program ◽  
Cushion Layer

The effects of deformation modulus, thickness and range of cushion layer on mechanical characteristics of spiral case in hydropower station has been analyzed using the finite element program ANSYS and nonlinear contact theory. The result shows that when cushion layer scope and poisson ratio is fixed, as the elastic modulus of cushion layer decreases, the deformation and stress of spiral case increases, surrounding concrete load-bearing ratio of water pressure reduces. If the cushion layer deformation modulus is fixed and the range of cushion layer extends to 10 degree site bellow the waist of spiral case, the steel spiral case stress decrease, the radial stress transferred from the spiral case to surrounding concrete increase by about from 0.01MPa to 0.03MPa, and load-bearing ratio of concrete increase, when the cushion layer Poisson ratio increases from 0.25 to 0.35.

scholarly journals ANALISIS PENGARUH TEKANAN AIR PORI PADA LERENG YANG DIPERKUAT DENGAN GEOTEKSTIL

2021 ◽  
Vol 4 (1) ◽  
pp. 139
Author(s):  
Satria Seprianto ◽  
Andryan Suhendra
Keyword(s):  
Tensile Strength ◽  
Pore Water ◽  
Safety Factor ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Slope Reinforcement ◽  
Slope Safety

ABSTRACTInfrastructure development in Indonesia is growing  rapidly. With the large number of infrastructure developments in various slope topographies, it is one of the locations that is part of this development. The slope area is prone to landslides so that strengthening is necessary. One of the reinforcement that can be done is with geotextiles. In its installation, it is necessary to calculate the correct length and strength of the geotextile for reinforcement. The tensile strength and length of the geotextile as well as the parameters of the embankment affect the safety factor of slope construction. One of the factors being considered is the pore water pressure which reduces the slope strength. So that the results of this study will show how much the influence of pore water pressure on slope reinforcement with geotextiles. After analysis, it was found that the increase of pore water pressure resulted in decreasing of slope safety factor.ABSTRAKPembangunan infarstruktur di Indonesia berkembang sangat pesat. Dengan banyaknya pembangunan imfrastruktur di berbagai topografi lereng menjadi salah satu lokasi yang menjadi bagian dalam pembangunan tersebut. Daerah lereng rawan akan terjadinya longsor sehingga perlu dilakukan perkuatan. Salah perkuatan yang dapat dilakukan adalah dengan geotekstil. Dalam pemasangannya dibutuhkan perhitungan panjang dan kuat geotekstil yang tepat untuk perkuatan. Kuat tarik dan panjang geotekstil serta parameter tanah timbunan mempengaruhi faktor keamanan konstruksi lereng. Salah satu faktor yang dipertimbangkan adalah tekanan air pori yang menjadi penurunan kekuatan lereng. Sehingga hasil studi ini akan menunjukkan seberapa besar pengaruh tekanan air pori pada perkuatan lereng dengang geotekstil. Setelah dilakukannya analisis didapatkan bahwa kenaikan tekanan air pori mengakibatkan penurunan nilai faktor keamanan lereng.

Floating-Roof Tank Heel Reduction Options and Heel Turnover Emissions

1998 ◽  
Author(s):  
Terry A. Gallagher ◽  
Royce J. Laverman ◽  
Christian R. Desjardins
Keyword(s):  
Cross Contamination ◽  
Working Capacity ◽  
Operating Level ◽  
Valuable Product ◽  
Product Inventory ◽  
Minimum Operating

The net working capacity of floating roof tanks is the product inventory that is stored between the maximum and minimum operating levels of the floating roof. The product that remains in the tank when the floating roof is at its minimum operating level is residual inventory, referred to as the product heel. This trapped inventory is a valuable product asset that is not part of the tank net working capacity. This paper describes considerations that must be made when lowering the minimum operating level of floating roofs, both for new and retrofit tank applications, and presents methods of achieving these improvements. Some tank turnover operations require that the floating roof be landed and the tank drained dry. Tank turnover operations include those where it is important to avoid cross contamination of products. Recent studies have shown the importance of the emissions that occur during heel turnover operations. This paper describes a method for determining the heel turnover emissions and presents abatement options for controlling these emissions.

scholarly journals Analysis of potential liquefaction of sandy soils using effective confining pressure

2020 ◽  
Vol 156 ◽  
pp. 02013
Author(s):  
Siti Nur Indah Sari
Keyword(s):  
Safety Factor ◽  
Sandy Soil ◽  
Sandy Soils ◽  
Confining Pressure ◽  
Resistance Ratio ◽  
Liquefaction Potential ◽  
Cyclic Resistance ◽  
The World ◽  
Cyclic Resistance Ratio ◽  
Central Sulawesi

Earthquake disasters are some of the most frequent disasters in the world. One of the impacts of earthquakes is liquefaction. Indonesia is earthquake-prone and has been negatively impacted by liquefaction. Recently liquefaction resulting from an earthquake in Palu, Central Sulawesi caused losses in terms of material and lives motivating a more detailed study of this risk to reduce it in the future. In this study, an analysis of the liquefaction potential of sandy soil was carried out by varying the effective confining pressure to produce a graph relating fine contents (FC) to cyclic resistance ratio (CRR).The value of the cyclic resistance ratio is needed to determine the safety factor for potential liquefaction.

Analysis for the Seepage Stability of the Upstream Cofferdam of One Hydropower Station

2013 ◽  
Vol 441 ◽  
pp. 286-290
Author(s):  
Yu Lin Yuan ◽  
Yun Feng Peng
Keyword(s):  
Safety Factor ◽  
Theoretical Basis ◽  
Circle Method ◽  
Control Design ◽  
Hydropower Station ◽  
Software Analysis ◽  
Seepage Control ◽  
Geological Conditions ◽  
The Stability

According to the geological conditions of upstream cofferdam and foundation of the hydropower station, analysis for the seepage of the upstream cofferdam used SEEP/W module of Geo-studio software. Analysis for the stability used SLOPE/W module with Swedish circle method and Bishop method. Safety factor of the upstream and downstream in different conditions was obtained. The results show that the design of the upstream cofferdam was reasonable, and it will provide theoretical basis for Seepage control design of cofferdam.

scholarly journals Study on Risk Assessment and Early Warning of Flood-Affected Areas when a Dam Break Occurs in a Mountain River

Water ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1369 ◽  
Author(s):  
Qiang Fan ◽  
Zhong Tian ◽  
Wei Wang
Keyword(s):  
Risk Assessment ◽  
Early Warning ◽  
Assessment Method ◽  
Research Literature ◽  
Dam Break ◽  
Hydropower Station ◽  
Risk Level ◽  
Mountain River ◽  
Flood Level ◽  
Study Results

Under the influence of extreme weather conditions or other unfavorable factors, if a dam break occurs in a mountain river, it will cause a great number of casualties and property losses in the affected downstream areas. Usually, early warning of the affected areas downstream of the dam depends mainly on qualitative evaluation and cannot be quantitatively evaluated. Based on the authors’ calculation of floods for many years, this study presents a quantitative assessment method for flood risk. The Ertan Hydropower Station in Southwest China and the flood-affected areas were chosen as the object of this study. Based on field surveys, research literature data, and the authors’ calculations, the basic data of the Ertan Hydropower Station and the calculation results of the dam break were obtained, and 35 representative flood-affected areas were selected to study risk assessment and early warning. The fuzzy analytic hierarchy process (FAHP) was used to build a mathematical model for quantitative analysis. The population, flood arrival time, flood level, evacuation time, and local GDP (Gross Domestic Product) were selected as five typical evaluation factors. Finally, this study calculated and counted the risk level of 35 representative flood-affected areas, and the study results were applied to Quxue and Guanmaozhou Hydropower Station.

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