The dam body has a modulus of elasticity e 35 gpa, poissons ratio. The section is so designed and shaped that its weight is sufficient to ensure. Gravity dams require maximum amounts of concrete for their construction as compared with other kinds of concrete dams, and resist dislocation by the hydrostatic pressure of reservoir water by sheer weight. Guidelines for construction cost estimating for dam engineers and owners was prepared by the ussd committee on construction and rehabilitation. Many concrete gravity dams have been in service for over 50 years, and over this period important advances in the methodologies for evaluation of natural phenomena hazards have caused the design. Dec 14, 2016 chapter 6 concrete dam engineering with examples 1. Gravity dam free download as powerpoint presentation.
A gravity dam is a solid structure, made of concrete or masonry, constructed across a river to create a reservoir on its upstream. A gravity dam has been defined as a structure which is designed in such a way that its own. Gravity dams are constructed from masonry or concrete. An example design of small african journals online. Learning outcome after this lecture, students should be able to 1. Example c7 shows how to calculate both the net buoyancy force exerted on a liquid propane tank in a wet floodproofing scenario and the volume of concrete needed to offset the buoyancy force. Often the depthsurface area curve usually with a reversed scale is added to these graphs. Gravity dam loads on concrete dams loads can be classified in terms of applicabilityrelative importance as primary loads, secondary loads, and exceptional loads. The purpose of this document is to give some examples of how risk analysis results are used to support risk management decisions.
Exercise problem 1 a concrete gravity dam 15 m height will be constructed with the dimensions shown in the figure below. The main aspects concerning gravity dams are presented along with their main failure causes. This thesis presents a twodimensional hydrodynamic stability analysis of gravity dams for the maximum design earthquake. For structures consisting of a section of concrete gravity dam within an. The second modern dam of the world was roosevelt dam constructed on the salt river of arizona u. Bob specializes in concrete gravity dam design and was involved in the first rollercompacted concrete rcc gravity dams constructed in pennsylvania, maryland, and california. Concrete dam engineering 1 0401544 hydraulic structures university of sharjah dept. Example c6 demonstrates how to size a sump pump for dry floodproofing. Gravity dams are designed so that each section of the dam is stable and independent of any other dam section. An earth dam require one hundred cubic meter of soil compacted with unit weight of 20. A simplified example of a depthcapacity curve is shown in figure 7. This manual presents instructions, examples, procedures, and standards for use in the design of concrete gravity dams. A gravity dam is a dam constructed from concrete or stone masonry and designed to hold back water by using the weight of the material alone to resist the horizontal pressure of water pushing against it. Chapter 6 concrete dam engineering with examples 1.
Gravity dams gravity dams criteria for selection of dam site, construction material, forces acting on gravity dam, modes of failure, stability analysis, safety criteria, methods of design, stress analysis and stress contours, galleries, instrumentation, joints, keys, water seals, temperature control in concrete dams, foundation. Ppt gravity dam powerpoint presentation free to view. This manual applies to all hqusace elements, major subordinate commands. Example on design of gravity dam free download as pdf file. Design and construction of concrete gravity dams nptel. The terms in figure 1 are defined in the dam safety public protection guidelines and are not repeated here.
Structural stability and 2d finite element analysis of. Gravity loads empty reservoir an insitu state of stress with an effective stress ratio. It has been written for engineers and owners engaged in the planning, design. For the calculation example the dam of birecik monograph is used. The dam with the largest reservoir capacity is owen falls dam, a 31 meters high gravity dam on the victoria nile in uganda, with 205 000 million cubic meters storage capacity including lake victoria.
The earthquake forces may be taken as equivalent to 0. Scribd is the worlds largest social reading and publishing site. Dams are classified on several aspects, some of the important aspects are as follow. Pdf analysis of structural safety of gravity dams researchgate. This oversight was only discovered after the dam had experienced significant downstream movement. Pdf this work compares the standards of three different countries of. Gravity dam dam civil engineering free 30day trial. The initial stress state resulting from the weight of the dam. Introduction the purpose of this paper is to consider and discuss the merits of the methods employed in the. The final example, example c8, demonstrates how to design a cantilevered.
Hydrogeological data five investigation boreholes have been drilled along the proposed axis of the dam to a depth rang ing between 15 and 31. For the love of physics walter lewin may 16, 2011 duration. In this method, the dam is considered to be composed of parallel sided vertical cantilevers. Guidelines for construction cost estimating for dam engineers. A tail water depth of 6m is assumed when the reservoir is. Forces acting on a gravity dams with diagram geography.
An earth dam is made of earth or soil built up by compacting successive layers of earth, using the most impervious materials to form a core and placing more permeable substances on the upstream and. Dam safety public protection guidelines examples of use. For example, the hills of the himalayan range of the mountains. The white paper provides support for responsible cost estimating for new dams and dam rehabilitation projects. Mar 04, 2014 for the love of physics walter lewin may 16, 2011 duration. Gravity dam definition of gravity dam by merriamwebster. Many concrete gravity dams have been in service for over 50 years, and over this period important advances in the methodologies for evaluation of natural phenomena hazards have caused the. Stability analysis of gravity dams question section of a gravity dam is. This method of stability analysis is also sometimes known as two dimensional methods. Gravity dams arch dams buttress dams 3 based on usage of dam. This cross section eventually evolved into the common triangular cross section design of todays gravity dams. The dam is composed of three blocks of equal heights. Ppt gravity dam powerpoint presentation free to view id. A drainage gallery is generally provided in order to relieve the uplift pressure exerted by the seeping water.
Material used in its construction was the solid blocks of concrete. Figure 1 shows the general input to risk management. The highest concretefaced rockfill dam cfrd is aguamilpa in mexico 187 meters high. The upstream face may be kept throughout vertical or partly slanting for some of its length. Comparison of design and analysis of concrete gravity dam 19. Stability analysis of concrete gravity dam on complicated foundation with multiple slide planes article pdf available in water science and engineering september 2008 with 2,740 reads. The purpose of this manual is to provide technical criteria and guidance for the planning and design of concrete gravity dams for civil works projects.
Failure of gravity dams causes and its failure modes. Gravity dam is constructed of concrete andor masonry andor laidup stone that relies upon its weight for stability. A gravity dam is designed in such a way that it resists all external forces acting on the dam like water pressure, wind pressure, wave pressure, ice pressure, uplift pressure by its own selfweight. The first version of a modern gravity dam was built between 1765 and 1800 in mexico. In 19982003, he served as the rcc design task leader for the olivenhain dam in san diego, california. View notes steability analysis of gravity dams example. A depthcapacity curve can then be drawn up to provide a quick and easy method for the dam designer to choose the optimum full supply level. Detailed design 6 food and agriculture organization. The average joint spacing is 50 m, with joints oriented at 20 and. The different components of concrete gravity dams and their layouts. Failure of gravity dam occurs due to overturning, sliding, tension and compression.
A gravity dam is a dam constructed from concrete or stone masonry and designed to hold back water by primarily using the weight of the material alone to resist the horizontal pressure of water pushing against it. A curved gravity dam resists the external forces by its weight and not by arch action. A gravity dam is a dam that holds water simply because of its own weight. Situated in the canton of valais in the val des dix, a contributory of the rhone river, the grandedixence scheme is well known for its concrete gravity dam, the highest concrete dam in the world, at 285 m high.
That is, the dam is so heavy the all the water in a full reservoir isnt able to push it out of its proper place. All the predominant forces that act on the dam have been shown in the figure itself. For example, in the case of morris shephard dam, 26 p1494, a horizontal seam underlaid the dam, provid ing a plane of weakness that was not. Comparison of design and analysis of concrete gravity dam. Gravity dam definition is a dam so proportioned that it will resist overturning and sliding forces by its own weight. The section of the gravity dam is approximately triangular in shape, with its apex at its top and maximum width at bottom. The coupled mechanical and hydraulic behavior of the dams rock mass foundation is taken into account. Pdf design and construction of gravity dams dian eka. Which was the type known as osolid masonry gravity dam. Pdf design of gravity dam by genetic algorithms researchgate. Pdf the design of a gravity dam is performed through an interactive process.
Grand coulee dam usa, nagarjuna sagar dam india and itaipu dam between brazil and paraguay. Stability analysis of gravity dams for the maximum design. Stability analysis of gravity dam using staad pro youtube. Height is the vertical dimension from the downstream toe of the dam at. Previous ferc gravity dam guidance dealt with nappe forces by ignoring. The following are the various methods which can be adopted for carrying out the stability analysis of gravity dams.
Design of gravity dam, calculation in reservoir full. For example, in the case of morris shephard dam, 26 p1494, a. Guidelines for construction cost estimating for dam. That is, the dam has a center of gravity low enough that the dam will not topple if unsupported at the abutments. A gravity dam is mostly straight in plan and is known as straight gravity dam. It is intended to implement an internal drainage facility, which would reduce uplift pressure by about 20%. Feb 08, 2018 a dams job is to hold a lot of water in place. Gravity dams gravity dams criteria for selection of dam site, construction material, forces acting on gravity dam, modes of failure, stability analysis, safety criteria, methods of design, stress analysis and stress contours, galleries, instrumentation, joints, keys, water seals, temperature control in concrete dams, foundation treatment. Later gravity dams used a trapezoidal cross section. The purpose of this paper is to consider and discuss the merits of the methods employed in the consideration and design of a concrete diversion dam designed by. An example of of a small design gravity dams by hailu yemanu, chief engineer of the awash valley authority and lecturer of fluid mechanics and hydraulics at the engineering college, haile selassie i uni versity 1.