Showing 3 results for alembagheri
Behzad Nikkhakian, Mohamad alembagheri,
Volume 18, Issue 1 (may 2018)
Abstract
Abstract. One of the most vital, essential human being requirements is water, which it has become increasingly sensitive owing to population growth, the need to develop agriculture and industry, and restriction in water resources. Considering this, the need to store water and to use its potential for generating hydroelectric power, which it can be achievable by constructing dams, will be necessitated. Concrete dams play a significant role in Infrastructure in each country. One important part of dams exiting in the world are made of gravity dams and earthquake seems to be the major threat for them in earthquake-prone areas. Hence, the dam fracture, with much stored water, might have brought many conspicuous threats about in these zones. Also, any structural damage could lead to some negative economic effects. These facts have increased the scholars’ attention to the mechanical behavior of dams during the decades. The Seismic analysis of gravity concrete dams, usually, had been considered in an ideal form by means of 2D Monolith in mechanism design and an earthquake effect coefficient. Lately, the research focus, however, has been more on linear time history analytics and fracture analysis of concrete dams in 3D. The numerical modelisation of huge structures such as dams is a proper tool for Seismic analysis and performance evaluation. The valley shape is one of the important parameters in the selection of the dam structure. This parameter plays a crucial role in both Seismic stimulation and its results. In this paper, a 3D finite element model of Pine-flat gravity dam, without interruption seams with a non-linear behavior of the dam’s material, is considered. . Loading has two stages: static and dynamic. In this modelisation, static loading includes both the weight of dam body and the load of filled Hydrostatic tanks. After static loading, loading of Seismic dynamic is begun. Owing to the importance of valley shape, the changes/ deformations of valley width and the dam response to every three elements of ground is investigated. The impact of the ratio changes of width in dam height, as well as the importance of the transverse component of ground motion, along the vertical and horizontal, has been explored. Interaction effects of dam-reservoir-foundation is considered in the considered analysis and ultimately, the output of which is compared with two dimensional model results. The aim of this study is comparing two and three dimensional seismic response of concrete gravity dams and also necessity of providing more realistic models for considering the effects of cross stream modes. Also, not only are interaction effects of dam-reservoir-foundation, the nonlinear behavior of concrete, studied different Valley shapes, and the effect of them on non-liner response investigated, but also the Seismic stability of gravity concrete dams under longitudinal, vertical and the chosen transverse record earthquake are separate and simultaneously studied. The effects of dam-reservoir-foundation interaction, nonlinear behavior of mass concrete, also different shapes of valley are studied and their effect on nonlinear response and seismic stability of concrete gravity dams are evaluated under two and three-component earthquake records.
Mohammad alembagheri, Reza Sheikhzadeh Shayan,
Volume 18, Issue 6 (12-2018)
Abstract
The Seismic analysis of concrete dams had been considered in an ideal form by means of two dimensional Monoliths in analyse and design procedures and structures had been subjected to ground motions with defining seismic coefficient. Lately, the research focus, however, has been more on linear time history analytics and fracture analysis of concrete dams in 3D space. With the advancement of knowledge in the field of earthquake engineering and the development of more precise methods for estimating the intensity of possible earthquakes, The methods of analyzing and evaluating the seismicity of the structures have been improved and the effects of more parameters can be considered in assessing the risk of each structure. In the present study, the seismic response of a concrete arch-gravity dam under the influence of earthquake stimulation is investigated in a three dimensional finite element analysis. The effects of dam-reservoir-foundation interactions are considered and the nonlinear behavior of the concrete and also the different patterns of the arc radius of the dam are studied. Finally, the contribution of response of each of the sustainability factors to seismic stimulation is evaluated. The Seismic analysis of concrete dams had been considered in an ideal form by means of two dimensional Monoliths in analyse and design procedures and structures had been subjected to ground motions with defining seismic coefficient. Lately, the research focus, however, has been more on linear time history analytics and fracture analysis of concrete dams in 3D space. With the advancement of knowledge in the field of earthquake engineering and the development of more precise methods for estimating the intensity of possible earthquakes, The methods of analyzing and evaluating the seismicity of the structures have been improved and the effects of more parameters can be considered in assessing the risk of each structure. In the present study, the seismic response of a concrete arch-gravity dam under the influence of earthquake stimulation is investigated in a three dimensional finite element analysis. The effects of dam-reservoir-foundation interactions are considered and the nonlinear behavior of the concrete and also the different patterns of the arc radius of the dam are studied. Finally, the contribution of response of each of the sustainability factors to seismic stimulation is evaluated. The Seismic analysis of concrete dams had been considered in an ideal form by means of two dimensional Monoliths in analyse and design procedures and structures had been subjected to ground motions with defining seismic coefficient. Lately, the research focus, however, has been more on linear time history analytics and fracture analysis of concrete dams in 3D space. With the advancement of knowledge in the field of earthquake engineering and the development of more precise methods for estimating the intensity of possible earthquakes, The methods of analyzing and evaluating the seismicity of the structures have been improved and the effects of more parameters can be considered in assessing the risk of each structure. In the present study, the seismic response of a concrete arch-gravity dam under the influence of earthquake stimulation is investigated in a three dimensional finite element analysis. The effects of dam-reservoir-foundation interactions are considered and the nonlinear behavior of the concrete and also the different patterns of the arc radius of the dam are studied. Finally, the contribution of response of each of the sustainability factors to seismic stimulation is evaluated.
Mohammad alembagheri, Hossein Behzadnasab,
Volume 19, Issue 1 (5-2019)
Abstract
The increasing need for clean water and energy resources for human societies has led them to optimize the old technologies with the best in research and studies to make the most of them. One of these inventions is dams, structures that are created on the rivers. In the past, the creation of dams was generally aimed at providing drinking water and irrigation of farms, but nowadays it is not only a source of water, but also electric energy. In many studies, dynamic analysis is used to assess the vulnerability and damage damages during an earthquake. Despite the precision of this method, there are many uncertainties in the analysis stages that make the study costly and prolonged. Therefore, using nonlinear static analysis method, researchers increased the speed of analysis and reduced costs. The purpose of this study is to investigate the seismic performance of concrete gravity dams using nonlinear static analysis (pushover analysis). For this purpose, load patterns used in the pushover analysis are applied in both directions upstream and downstream of the dam structure. Observations show that, apart from the rectangular load pattern, all load patterns used in this research can adequately correlate Detect the crack in the dam body correctly. The increasing need for clean water and energy resources for human societies has led them to optimize the old technologies with the best in research and studies to make the most of them. One of these inventions is dams, structures that are created on the rivers. In the past, the creation of dams was generally aimed at providing drinking water and irrigation of farms, but nowadays it is not only a source of water, but also electric energy. In many studies, dynamic analysis is used to assess the vulnerability and damage damages during an earthquake. Despite the precision of this method, there are many uncertainties in the analysis stages that make the study costly and prolonged. Therefore, using nonlinear static analysis method, researchers increased the speed of analysis and reduced costs. The purpose of this study is to investigate the seismic performance of concrete gravity dams using nonlinear static analysis (pushover analysis). For this purpose, load patterns used in the pushover analysis are applied in both directions upstream and downstream of the dam structure. Observations show that, apart from the rectangular load pattern, all load patterns used in this research can adequately correlate Detect the crack in the dam body correctly. The increasing need for clean water and energy resources for human societies has led them to optimize the old technologies with the best in research and studies to make the most of them. One of these inventions is dams, structures that are created on the rivers. In the past, the creation of dams was generally aimed at providing drinking water and irrigation of farms, but nowadays it is not only a source of water, but also electric energy. In many studies, dynamic analysis is used to assess the vulnerability and damage damages during an earthquake. Despite the precision of this method, there are many uncertainties in the analysis stages that make the study costly and prolonged. Therefore, using nonlinear static analysis method, researchers increased the speed of analysis and reduced costs. The purpose of this study is to investigate the seismic performance of concrete gravity dams using nonlinear static analysis (pushover analysis). For this purpose, load patterns used in the pushover analysis are applied in both directions upstream and downstream of the dam structure. Observations show that, apart from the rectangular load pattern, all load patterns used in this research can adequately correlate Detect the crack in the dam body correctly.