scholarly journals DYNAMIC RESPONSE AND STABILITY ANALYSES OF AKOSOMBO DAM USING NUMERICAL ANALYSIS

2021 ◽  
Vol 9 (10) ◽  
pp. 639-655
Author(s):  
Stephen A. Irinyemi ◽  
◽  
Domenico Lombardi ◽  
Syed M. Ahmad ◽  
◽  
...  
Keyword(s):  
Large Scale ◽  
Numerical Procedure ◽  
Embankment Dam ◽  
Embankment Dams ◽  
The People ◽  
Acceleration Time Histories ◽  
Non Linear ◽  
Time Histories ◽  
The Stability ◽  
Design Earthquake

Dams are very important in Ghanas economic development and environmental improvement. Although Ghana dams are seismically far from the active zone, accurately analysed dams should be evaluated since failure could severely impact the people in the flood environment and the regions economy on a large scale. This paper proposes a numerical procedure for the static, slope stability, and dynamic analysis of the Akosombo embankment dam. Nineteen horizontal acceleration time histories recorded data was used based on Maximum Design Earthquake (MDE), Maximum Credible Earthquake (MCE), Design Basis Earthquake (DBE) and Operating Basis Earthquake (OBE) data. The numerical results estimated showed that the Akosombo embankment dam is likely to experience moderate deformations during the different design earthquakes. The result also indicated that non-linear analysis capable of capturing dominant non-linear mechanisms could be used to assess the stability of embankment dams. The factor of safety (FS) calculated was greater than 1.5 for high reservoir, rapid drawdown condition and low reservoir condition whereas, the FS values were found to be 1.42 for slow drawdown condition.

Geologic and seismic setting pertinent to dam safety review of Duncan Dam

1994 ◽  
Vol 31 (6) ◽  
pp. 919-926 ◽  
Author(s):  
Tim E. Little ◽  
Alan S. Imrie ◽  
John F. Psutka
Keyword(s):  
Ground Motion ◽  
Ground Motions ◽  
Probabilistic Methods ◽  
Dam Safety ◽  
Embankment Dam ◽  
Seismic Ground Motion ◽  
Time Histories ◽  
Peak Horizontal Acceleration ◽  
Design Earthquake ◽  
Selection Of

Duncan Dam is a B.C. Hydro facility constructed on the Duncan River in southeastern British Columbia, Canada, between 1965 and 1967. The dam was founded on a complex sequence of more than 380 m of glacial drift and glaciofluvial sediments, some of which are pervious and compressible. Some sandy units are potentially liquefiable, in particular a sand layer (unit 3c) up to 23 m thick. Current B.C. Hydro seismic guidelines for dams require that Duncan Dam should be able to withstand the Maximum Credible Earthquake (MCE) without catastrophic release of the reservoir. This paper describes the geologic and seismic setting of the region around the dam and the selection of seismic ground motion parameters. Probabilistic methods were applied to develop MCE ground motions, which were estimated to consist of a firm ground peak horizontal acceleration of 0.12 g, which could be caused by a M 6.5 earthquake at a distance of about 50 km. Several time histories with characteristics similar to this design earthquake were selected for dynamic soil analyses. Key words : dam safety, embankment dam, liquefaction, sand, seismicity, seismic ground motion.

Application Discussion on the Bifurcation and Nonlinear Dynamic Theory in Mines

2013 ◽  
Vol 448-453 ◽  
pp. 3843-3846
Author(s):  
Chuan Peng Wang ◽  
Long Hao Dong ◽  
Zhi Chao Tian
Keyword(s):  
Rock Mass ◽  
Large Scale ◽  
Dynamic Theory ◽  
Physical Property ◽  
Progressive Damage ◽  
Linear Dynamics ◽  
Non Linear ◽  
Safety Production ◽  
Research Procedure ◽  
The Stability

Mining is a large-scale and highly complex misalignment system. The progressive damage and disorder development of the rock mass distort as well as the development that the rock mass evolution curve changes from the linear constant speed stage to the distortion stage which is accelerated by misalignment threaten the safety production in mines seriously. Therefore, the research on the rock mass distortion destroys plays an important part in guaranteeing the safety production in mines. This article elaborates the non-linear dynamics branch theory in detail, analyzes the branch phenomenon in slow change and stress-strain of rock mass according to its characteristics and advances the research procedure of the non-linear dynamics branch theory in mining. Moreover, it establishes the dynamic model according to the physical property of system and determines the stability of system using the branch theory.

THE EFFECT OF EARTHQUAKE ACCELERATION RECORDS AND THEIR EQUIVALENT DYNAMIC LOADS ON EARTH-DAM RESPONSES

2017 ◽  
Vol 4 (1) ◽  
Author(s):  
Sara Mamani ◽  
Siamak Yazdani
Keyword(s):  
Dynamic Analysis ◽  
Performance Indicator ◽  
Earth Dam ◽  
Harmonic Load ◽  
Acceleration Time ◽  
Linear Dynamic ◽  
Earthquake Records ◽  
Acceleration Time Histories ◽  
Non Linear ◽  
Time Histories

This paper studies the dynamic behavior of a typical earth-dam using non-linear dynamic analysis under different earthquake records. One of the most important components in non-linear dynamic analysis of earth-dams is the evaluation of their stability considering the permanent displacement as a performance indicator. Varieties in acceleration time histories coupled with various geometry and heterogeneous material properties of the earth structures lead to diversity in non-linear responses under different real accelerograms. In this study, an equivalent harmonic load related to earthquake records with specific magnitude and frequency is defined and is applied to a 70m tall earth-dam during four real acceleration time histories. The induced-displacements were then measured under each real time record along with their defined harmonic loads at the dam crest. The resulting displacements and their harmonic equivalent loads are compared showing a good agreement in their deformations at the crest. Appropriate parameters including equivalent number of cycles and peak ground acceleration (PGA) for unique equivalent harmonic load were obtained based on the response analyses.

scholarly journals Organizational Democracy in the Private Sector: A Field Research

2020 ◽  
Vol 12 (8) ◽  
pp. 3446
Author(s):  
Hurriyet Bilge ◽  
Nicoleta Barbuta-Misu ◽  
Deniz Zungun ◽  
Florina Oana Virlanuta ◽  
Huseyin Guven
Keyword(s):  
Private Sector ◽  
Organizational Performance ◽  
Large Scale ◽  
Business Processes ◽  
High School Graduates ◽  
Field Research ◽  
Organizational Democracy ◽  
The People ◽  
Perceptions And Attitudes ◽  
The Stability

The process of organizational democracy involves a process of associating employees’ participation and satisfaction in business processes, increased innovation, increased stakeholder engagement and ultimately increased organizational performance. Organizations and the people that form the organization adapt democracy to achieve social and economic goals by making use of the blessings of democracy. In this way, they aim to reach their goals and to include all members of the organization in the process while achieving these goals, and to sustain the stability. The main purpose of this study is to analyze the democracy perceptions of blue and white collar employees in the private sector through organizational democracy scales, by using various variables and to contribute to the existing literature. The sample of the study constitutes 209 people, white and blue collar employees at various levels in medium and large scale enterprises in the Manisa Organized Industrial Zone in Turkey. As a result of the study, it is seen that married employees and employees who think that their expertise in the job is good have the power to criticize their businesses and exhibit participation. In addition, it has been concluded that employees that are high school graduates see management fairer in terms of salary than other graduates. Another finding in the study is about the size of the pre-work life centers of the workplace. Perceptions and attitudes of the people living in metropolitan and provincial center metros before work observed that more equality was observed in the workplaces than those living in the district centers.

scholarly journals Parametric Analysis of an Embankment Dam’s Stability

2019 ◽  
Vol 9 (6) ◽  
pp. 5016-5020
Author(s):  
A. H. Bhutto ◽  
S. Zardari ◽  
G. S. Bhurgri ◽  
M. A. Zardari ◽  
R. Bhanbhro ◽  
...  
Keyword(s):  
Parametric Analysis ◽  
Friction Angle ◽  
Soil Conditions ◽  
Embankment Dam ◽  
Strength Parameters ◽  
Sandy Gravel ◽  
Embankment Dams ◽  
The Stability

This paper presents a stability parametric analysis of a 59m high embankment dam. The analysis was performed in order to evaluate the minimum values of strength parameters that satisfy the stability requirements of the dam. The parametric analysis was conducted for three main zones of the dam: upstream shell, core, and downstream shell, which consisted of sandy gravel, clay, and random fill respectively. The friction angles of these materials were gradually decreased in order to represent different soil conditions. It was observed that stability requirements for the end of construction and after the filling of the reservoir could be satisfied if friction angle values of the sandy gravel and the random fill are 34º and 32º, instead of 37º and 34º. However, the value of the core’s cohesion could be utilized as 30º without any reduction so that the dam could be safe after the filling of the reservoir. The results of this study could be beneficial to practicing engineers for the design of safe and economical embankment dams.

Etude de l'aménagement d'une forêt classée au Mali avec la participation des populations riveraines - Données du problème et éléments de méthodologie | A Study of the Management of a State-Owned Forest in Mali with the Participation of the Population Living nearby - Issue under Investigation and Elements of Methodology

2000 ◽  
Vol 151 (3) ◽  
pp. 80-83
Author(s):  
Pascal Schneider ◽  
Jean-Pierre Sorg
Keyword(s):  
Natural Resources ◽  
Research Methodology ◽  
Large Scale ◽  
Environmental Context ◽  
Forest Resources ◽  
The State ◽  
Commercial Use ◽  
Economic Context ◽  
The People

In and around the state-owned forest of Farako in the region of Sikasso, Mali, a large-scale study focused on finding a compromise allowing the existential and legitimate needs of the population to be met and at the same time conserving the forest resources in the long term. The first step in research was to sketch out the rural socio-economic context and determine the needs for natural resources for autoconsumption and commercial use as well as the demand for non-material forest services. Simultaneously, the environmental context of the forest and the resources available were evaluated by means of inventories with regard to quality and quantity. According to an in-depth comparison between demand and potential, there is a differentiated view of the suitability of the forest to meet the needs of the people living nearby. Propositions for a multipurpose management of the forest were drawn up. This contribution deals with some basic elements of research methodology as well as with results of the study.

Investigation of the stability of periodic motions in a nonlinear automatic control system based on the fast fourier transform

2003 ◽  
Vol 3 ◽  
pp. 297-307
Author(s):  
V.V. Denisov
Keyword(s):  
Fourier Transform ◽  
Control System ◽  
Automatic Control ◽  
Fast Fourier Transform ◽  
Automatic Control System ◽  
Resonance Phenomenon ◽  
Periodic Motions ◽  
Multiply Connected ◽  
Non Linear ◽  
The Stability

An approach to the study of the stability of non-linear multiply connected systems of automatic control by means of a fast Fourier transform and the resonance phenomenon is considered.

Popular Resource Sovereignty

2018 ◽  
Author(s):  
Leif Wenar
Keyword(s):  
Human Rights ◽  
Natural Resources ◽  
Large Scale ◽  
Good Reason ◽  
Resource Curse ◽  
Civil Conflict ◽  
Popular Sovereignty ◽  
State Sovereignty ◽  
The People ◽  
Rich Countries

Article 1 of both of the major human rights covenants declares that the people of each country “shall freely dispose of their natural wealth and resources.” This chapter considers what conditions would have to hold for the people of a country to exercise this right—and why public accountability over natural resources is the only realistic solution to the “resource curse,” which makes resource-rich countries more prone to authoritarianism, civil conflict, and large-scale corruption. It also discusses why cosmopolitans, who have often been highly critical of prerogatives of state sovereignty, have good reason to endorse popular sovereignty over natural resources. Those who hope for more cosmopolitan institutions should see strengthening popular resource sovereignty as the most responsible path to achieving their own goals.

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