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 optimum location of the drainage gallery underneath gravity dam is the goal of this study. A gravity dam built up of boxes, crossed timbers, or gabions filled with earth. Types of dams, advantages, disadvantages and classification. The introduction of an additional drainage gallery together with two lines of inclined drains, in all galleries. Gravity structures depend mainly upon its own weight to resist the effecting forces, specially upward force. Arch gravity dams are types of dams that use combined engineering methods of arch dams and gravity dams. Upward force can be reduced by using a drainage gallery somewhere beneath the floor of the structure. It includes a 250 m high rcc gravity dam which is the worlds highest of its kind. A dam built to divert water from a waterway or stream into a different watercourse. Concrete gravity dams should be evaluated to accommodate full. Pdf shape optimization of gravity dams using genetic algorithm. 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. Thousands of new, highquality pictures added every day.
The foundation for a gravity dam is most important sound rock is best, but smaller dams have performed well on soft foundations. The dam of the tgp is a concrete gravity dam with crest length 2309. Gravity dam is so proportioned that its own weight resists the forces acting upon it. 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. Any structure in a reservoir, dam, or river through which water can be drawn into an outlet pipe, flume, etc. A gravity dam built up of boxes, crossed timbers or gabions, filled with earth or rock. Figure 1 shows the system of forces that acts on a typical dam.
Subcategories this category has the following 9 subcategories, out of 9 total. The solid head or massive buttress dam is the most prominent modern variant of the type, and may be considered for conceptual purposes as a lightened version of the gravity dam. Gravity dam dam civil engineering free 30day trial. Oct 09, 2019 the main purpose of providing foundation drainage gallery is to collect seepage water from the foundation and body of the dam, and drain it out. The construction joints in a concrete gravity dams provide passage through the dam which unless sealed, would permit the leakage of water from the reservoir to. In fact, it can be noticed that, mainly for traditional reasons, straight gravity structures, conventional or rcc gravity dams, but also fill dams with a core or a. Gravity dams may be classified by plan as straight gravity dams and curved gravity. The junction of the upstream face of a gravity or arch dam with the foundation surface. Pdf gravity dams depend mainly on its own mass to resist the effecting uplift pressure. Gravity dams are a type of dam which is secured by making it of such a size and shape that it will resist overturning, sliding or crushing at the toe. This manual applies to all hqusace elements, major subordinate commands. The tallest embankment dam and second tallest dam in the world is the 300 m 984 ft nurek dam in tajikistan. The solid form is the more widely used of the two, though the hollow dam is frequently more economical to construct. The dead loads consider ed should include weights of concrete and superimposed back fill, and appurtenances such as gates and bridges.
An arch dam that is curved both vertically and horizontally. Operation, maintenance, and safety inspection dam maintenance factors factors that affect proper maintenance of dams. Galleries are also needed in higher dams because of the increased water pressure associated with restraining more water causes increased internal flows through the dam. Concrete dam engineering 1 0401544 hydraulic structures university of sharjah dept. Galleries are used in higher dams because an easier access for foundation drains is provided, and a reduction in mass is considered economical. A curved gravity dam resists the external forces by its weight and not by arch action. The large volume of concrete in a gravity dam normally justifies an onsite.
Drainage gallery is very critical in case of gravity dam. Jun 03, 2019 types of dams, advantages, disadvantages and classification. In the case of an embankment dam the junction is referred to as the upstream toe of the dam. Design and construction considerations for hydraulic structures.
Code of practice for drainage system for gravity dams, their foundations and abutments. It has a height of 221 metres 726 feet from its foundations, a crest length of 379 metres 1,244 feet, and a. Archgravity dams are the types of dams that use combined engineering methods of arch dams and gravity dams. 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. A gravity dam is mostly straight in plan and is known as straight gravity dam. Dams are made from a variety of materials such as rock, steel and wood.
The gravity method of the analysis does not consider the size of opening and the elastic property of dam material. Pdf design and construction of gravity dams dian eka. The need to incorporate spillways, outlet works, galleries, joint treatments, and other features and treatments. In total 16 million m 3 of concrete is used for the construction of the dam. Finite element analysis of gravity dam with drainage gallery. As solid gravity dams resist the overturning moments due to all external forces such as water pressure, slit pressure etc by its own weight only, these are known as solid gravity dams.
Pdf this study investigates the optimum location of drainage galleries of concrete. In structural concept the buttress dam consists of a continuous upstream face supported at regular intervals by downstream buttresses. A dam constructed of concrete andor masonry, which relies on its weight and internal strength for stability. 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. Chapter 6 concrete dam engineering with examples 1.
Failure of gravity dam occurs due to overturning, sliding, tension and compression. Numerical three dimensional fea 1 flow analysis is a very efficient method for the stress analysis of the subsurface drainage systems of concrete gravity dams. Recommendations for lighting, ventilation and other facilities inside the dam. Figure 1 forces acting on a concrete gravity dam the correlation between these forces, to maintain equilibrium, is given by the expression. Thus the objective of study is comprises of the finite. Pdf on the optimum layout of a drainage gallery in concrete. The type and configuration of a dam are primarily dictated by site conditions. Drainage system for earth and rockfill dams code of practice.
A concrete gravity dam is a massive concrete structure, roughly triangular in shape, and designed so that its weight ensures structural stability against the hydrostatic pressure of the impounded water and other forces that may act on the dam. Gravity dams are classified as solid or hollow and are generally made of either concrete or masonry. The tallest dam in the world is the jinpingi dam, an arch dam in china at 305 m 1,001 ft. Instability can occur by either overturning or sliding along the foundation contact or along horizontal cracks or even construction lift lines. Gravity dams depend on their own weight for structural stability. Forces acting on a gravity dams with diagram geography. Pdf finite element analysis of gravity dam with drainage. Gravity dams are designed so that each section of the dam is stable and independent of any other dam section.
Previous ferc gravity dam guidance dealt with nappe forces by. Numerical threedimensional fea 1 flow analysis is a very efficient method for the stress analysis of the subsurface drainage systems of concrete gravity dams. Gravity dams are solid concrete structures that maintain their stability against design loads from the geometric shape and the mass and strength of the concrete. The plant, with its 1870 mw of installed power and 6400 gwh of annual energy production, is one of the most important projects in the ethiopian governments commitment to meet the countrys present and future power. Design and construction of concrete gravity dams nptel. The main gallery is located near the us face of the dam as shown in the figure below. Learning outcome after this lecture, students should be able to 1. Design and construction considerations for hydraulic structures in addition, appendices are included that contain guide specifications for rcc construction appendix a, a summary of rcc costs appendix b, and samples of adiabatic temperature rise tests of rcc appendix c. A dam constructed of concrete andor masonry on the outside but having a hollow interior relying on its weight for stability. Public safety standards of the republic of india law is the. What is the significance of drainage gallery in a dam.
Optimal position of drainage gallery underneath gravity dam. The dam will have a nonoverflow section on the western side and a channel spillway section on the eastern side ministry of water recourses and electric power of. The main purpose of providing foundation drainage gallery is to collect seepage water from the foundation and body of the dam, and drain it out. The most ancient gravity dam on record was built in egypt more than 400 years b. Numerical threedimensional fea 1 flow analysis is a very efficient method for the stress analysis of the. Classification the higher the class the higher the standard of duty and standard of care required and watershed characteristics. Earth embankment gravity dams, for example, are well suited for sites with deep bedrock or soft foundation material. Galleries are also needed in higher dams because of the increased water pressure associated with restraining more water causes increased internal flows through the. Gravity dams are constructed from masonry or concrete.
Rcc dam, excess seepage, transverse joint, investigation, crack introduction the enlarged cotter dam is an 87m high roller compacted concrete rcc gravity dam, located west of canberra on the cotter river. A dam is a structure built across a stream, river or estuary to retain water. Optimization of concrete gravity dams foundation drainage. The rigid dam which is constructed either with stone or brick masonry or mass concrete, is called a solid gravity dam. Forces acting on a gravity dam following are forces acting on a gravity dam. Fem modeling of concrete gravity dams 3 figure 3 an aerial photo of the baozhusi dam and hydropower station. Gravity dam loads on concrete dams loads can be classified in terms of applicabilityrelative importance as primary loads, secondary loads, and exceptional loads. The effect of uplift pressure can be reduced by using a. Archgravity dams are types of dams that use combined engineering methods of arch dams and gravity dams. Concrete gravity dams usually run in a straight line across a broad valley and resist the horizontal thrust of the retained water entirely by their own weight. The dam was constructed between 2009 and 20 by the bulk water alliance. Hoover dam, built on the colorado river at the arizonanevada border between 1931 and 1936, is an outstanding example of a curved gravity dam built in a narrow gorge across a major river and employing advanced design principles. Uplift pressues, shear strengths, and tensile strengths for stability analysis of concrete gravity dams, volume i, epri tr100345. The tallest gravity dam is the 285 m 935 ft high grande dixence dam in switzerland.