The Experts below are selected from a list of 246 Experts worldwide ranked by ideXlab platform
Huang Zhimi - One of the best experts on this subject based on the ideXlab platform.
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Layout of primary and secondary stilling basin Downstream low head barrage
Advances in Science and Technology of Water Resources, 2020Co-Authors: Huang ZhimiAbstract:Because of the Downstream river water-level degradation and river bed cutting,the Downstream energy dissipator of barrage cannot operate normally,the improvement or reconstruction is needed for the energy dissipator. Based on the research results of the hydraulic model test of improvement and reconstruction of three barrages in Guangdong Province,a reasonable layout of barrage Downstream two stilling basin is studied. The optimization measures of primary stilling basin end still top height,and the outer bulging step provided in its Downstream Slope are given. The flow energy dissipation rate of stilling basin is greatly improved,the energy dissipator facilities are simplified,and the project investment is reduced.
Nihat Sinan Isik - One of the best experts on this subject based on the ideXlab platform.
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A study on geotechnical characterization and stability of Downstream Slope of a tailings dam to improve its storage capacity (Turkey)
Environmental Earth Sciences, 2013Co-Authors: Nazli Tunar Ozcan, Resat Ulusay, Nihat Sinan IsikAbstract:Tailings, waste products of the ore-dressing processes, are usually stored in a slurry form and pumped into sedimentation pond which is surrounded by natural heights and/or artificial walls. The database of International Commission of Large Dams and United Nations Environment Programme showed that several hundreds of tailings dam have failed since 1910. One of the reasons of these failures is Slope instability. Construction of mine tailings dams in Turkey has started to increase, particularly in the recent decade. This paper focuses the study undertaken to assess the geotechnical characteristics and stability of Downstream Slope of a tailings dam at a copper-zinc mine in the Black Sea Region of Turkey. At the mine site there are two tailings dams located at two different elevations. The upper dam was completely filled and is out of service. Increasing amount of tailings filling the pond of the lower dam resulted in a limited storage, and therefore, it has been decided that heightening of the dam about 7 m to improve its storage facility would be necessary. For the purpose, a series of investigations in the vicinity of the tailings dam and some geomechanical laboratory tests were carried in conjunction with the use of empirical methods to determine mechanical properties of the current dam material, tailings and the rockfill material that will be used for heightening of the dam. The results of the static and pseudo-static stability analyses based on the methods of limit equilibrium and numerical modelling indicated that circular and non-circular failures are the most critical modes of failure for the dam and safety factor gradually decreases when the tailings rise up to a specific elevation in the pond. However, the ranges of the calculated safety factors from both methods are considerably similar and suitable for heightening of the dam by 7 m in terms of stability. The results suggest that any instability is not expected under both static and dynamic conditions after the current height of the tailings dam is increased by 7 m, if the Slope geometry considered in the analyses is not changed and the tailings in the pond do not rise up to an elevation of about 475 m. In addition, magnitude of permanent settlement of the dam due to a probable earthquake was also assessed using two empirical methods and the results from both methods showed similar amount of settlements which were in tolerable limits.
Chen Li - One of the best experts on this subject based on the ideXlab platform.
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Water damage mechanism of surface and Downstream side of spur dike
Journal of chemical and pharmaceutical research, 2020Co-Authors: Chen Li, Wang Ping-yiAbstract:At present the research on water damage mechanism of spur dike are more confined to dike head, but that a large number of water damage phenomenon happened in the dike surface and Downstream Slope is found through analysing the field investigation and experimental phenomenon. This article first simulates the boundary condition on water damage of dike surface and Downstream Slope, and then observe the process of washout, so that reveals its mechanism. When the dike body is riprapping, destructive flow condition of recession period and the next flood season, leading to the unstable of dike body and the large pressure difference between its front and back, will cause dike surface and Downstream Slope be destroyed. When the dike body is riprapping and dike furface is concrete hinge, stream of overflowing dam with an apparently downward acting force causes the serious erosion on the Downstream side. With the development of the scour process, local large permeable rate basis area will be scoured much more seriously. When the dam surface is unable to bear the force down to the dam crest from the downward water flow, it will be collapsed.
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preliminary experimental study on construction technology of prestressed anchor cable for Downstream Slope protection of tailrace of xiangjiaba hydropower station
Water Resources and Hydropower Engineering, 2010Co-Authors: Chen LiAbstract:Based on two experiments made on all the phases of the technology for the construction of the prestressed anchor cable for Downstream Slope protection of the tailrace of Xiangjiaba Hydropower Station,the technology applicable for the construction of the prestressed anchor cable in the foundation with deeper overburden(consists of sandy gravel layer;crushed rock and silt laden layer;boulder layer;etc.) is preliminarily studied herein.The experiment shows that the technology can meet the design requirement,and then can be popularized to the similar project concerned.
Pembra Juned Adipura - One of the best experts on this subject based on the ideXlab platform.
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influence of baffle block and weir Downstream Slope at stilling basin of solid roller bucket type on hydraulic jump and energy dissipation
AIP Conference Proceedings, 2018Co-Authors: Jaji Abdurrosyid, Gurawan Djati Wibowo, Ika Setiyaningsih, Pembra Juned AdipuraAbstract:Weir is a water structure built crossing a river to elevate the water level or the channel that will be directed to the irrigation network. The rise in water level due to damming will result in rapid flow to Downstream. The change of flow from supercritical to subcritical will create a hydraulic jump. In order to reduce the energy contained in the flow, it is necessary to build an energy dissipater, which is stilling basin. The purpose of this research was to know the influence of Downstream weir Slope and the influence of baffle blocks arrangement on hydraulic jumps and energy dissipation on the solid-roller bucket. The research was conducted at Hydraulics Laboratory of Civil Engineering Department, Faculty of Engineering, UMS. This study used an open flume with dimension of 30×60×1000 cm with a channel bed Slope of 0.0058, an ogee spillway with a downward Slope of 1: 4, 2: 4, 3: 4, 4: 4, and a solid-roller bucket stilling basin with baffle blocks of 5/12 R. The study was conducted on sixteen treatments (Downstream Slope and placement baffle blocks) wit h four variations of water discharge, in which the flow turbulence, the length of the whirlpool and energy loss of each discharge were tested. The results show some conclusions. First, the increasing flow triggers the greater turbulence, the length of hydraulic jump Downstream of the vortex, and the smaller value of the percentage of energy loss. Second, the most effective baffle block arrangement in reducing turbulence and hydraulic jumps is the one that is placed at the center of the curved radius. Third, the efficiency of energy loss increases with reduced discharge variation, the treatment without baffle blocks is the most effective. Fourth, with the same flow rate of the Downstream body weir variation, there is insignificant difference to the flow turbulence and energy loss except for the hydraulic jump length, which is the most effective 4: 4 Slope.Weir is a water structure built crossing a river to elevate the water level or the channel that will be directed to the irrigation network. The rise in water level due to damming will result in rapid flow to Downstream. The change of flow from supercritical to subcritical will create a hydraulic jump. In order to reduce the energy contained in the flow, it is necessary to build an energy dissipater, which is stilling basin. The purpose of this research was to know the influence of Downstream weir Slope and the influence of baffle blocks arrangement on hydraulic jumps and energy dissipation on the solid-roller bucket. The research was conducted at Hydraulics Laboratory of Civil Engineering Department, Faculty of Engineering, UMS. This study used an open flume with dimension of 30×60×1000 cm with a channel bed Slope of 0.0058, an ogee spillway with a downward Slope of 1: 4, 2: 4, 3: 4, 4: 4, and a solid-roller bucket stilling basin with baffle blocks of 5/12 R. The study was conducted on sixteen treatments ...
Nazli Tunar Ozcan - One of the best experts on this subject based on the ideXlab platform.
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A study on geotechnical characterization and stability of Downstream Slope of a tailings dam to improve its storage capacity (Turkey)
Environmental Earth Sciences, 2013Co-Authors: Nazli Tunar Ozcan, Resat Ulusay, Nihat Sinan IsikAbstract:Tailings, waste products of the ore-dressing processes, are usually stored in a slurry form and pumped into sedimentation pond which is surrounded by natural heights and/or artificial walls. The database of International Commission of Large Dams and United Nations Environment Programme showed that several hundreds of tailings dam have failed since 1910. One of the reasons of these failures is Slope instability. Construction of mine tailings dams in Turkey has started to increase, particularly in the recent decade. This paper focuses the study undertaken to assess the geotechnical characteristics and stability of Downstream Slope of a tailings dam at a copper-zinc mine in the Black Sea Region of Turkey. At the mine site there are two tailings dams located at two different elevations. The upper dam was completely filled and is out of service. Increasing amount of tailings filling the pond of the lower dam resulted in a limited storage, and therefore, it has been decided that heightening of the dam about 7 m to improve its storage facility would be necessary. For the purpose, a series of investigations in the vicinity of the tailings dam and some geomechanical laboratory tests were carried in conjunction with the use of empirical methods to determine mechanical properties of the current dam material, tailings and the rockfill material that will be used for heightening of the dam. The results of the static and pseudo-static stability analyses based on the methods of limit equilibrium and numerical modelling indicated that circular and non-circular failures are the most critical modes of failure for the dam and safety factor gradually decreases when the tailings rise up to a specific elevation in the pond. However, the ranges of the calculated safety factors from both methods are considerably similar and suitable for heightening of the dam by 7 m in terms of stability. The results suggest that any instability is not expected under both static and dynamic conditions after the current height of the tailings dam is increased by 7 m, if the Slope geometry considered in the analyses is not changed and the tailings in the pond do not rise up to an elevation of about 475 m. In addition, magnitude of permanent settlement of the dam due to a probable earthquake was also assessed using two empirical methods and the results from both methods showed similar amount of settlements which were in tolerable limits.