Gravity dams are solid concrete structures that maintain their stability against design loads from the geometric shape, mass and strength of the concrete. A crib dam is a gravity dam built up of boxes, crossed timbers, or gabions filled with earth or rock. The junction of the upstream face of a gravity or arch dam with the foundation surface. Ppt gravity dam powerpoint presentation free to view. A drainage gallery is generally provided in order to relieve the uplift pressure exerted by the seeping water. The balance of the water load is transferred to the foundation by cantilever action. 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. Pdf design and analysis of concrete gravity dams researchgate. These drains are required to intercept any seeping water from the reservoir through the upstream face of the concrete dam. The upstream face may be kept throughout vertical or partly slanting for some of its length. In this paper, the high concrete dam of longtan was used as an example, using the abaqus program based on the extended finite element method to analyze the longtan dam under static and dynamic conditions which has been commonly used for the study of crack growth. Hydraulic structures for flow diversion and storage. They are designed to hold back large volumes of water. The main features for stability analyses of concrete gravity dams are presented.
I a simplified analysis procedure in which the response due only to the fundamental vibration mode is estimated directly from the earthquake design spectrum. Relative movement at joints and cracks, seepage flows, and hydrostatic uplift are also very important. 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. A gravity dam is a massive sized dam fabricated from concrete or stone masonry. Gravity dam loads on concrete dams loads can be classified in terms of applicabilityrelative importance as primary loads, secondary loads, and exceptional loads.
The following thesis emphasises on estimation of the probability of one specific failure mode, i. This discussion addresses the onsite inspection of concrete and masonry dams and presents information with regard to the recognition of potential dam safety concerns. Nptel civil engineering water resources engineering. In structural concept the buttress dam consists of a continuous upstream face supported at regular intervals by downstream buttresses. Pdf gravity dam design engineer manual ivan ramirez. The ratio of base width to the height of these dams is less than 1.
Design of gravity dam, calculation in reservoir full. A gravity dam depends on its own weight for stability and is usually straight in plan although sometimes slightly curved. Water in the reservoir upstream of the dam pushes horizontally against the dam, and the weight of the gravity dam pushes. Curved gravity dams designed for arch action and other types of concrete gravity dams are not covered in this manual. A gravity dam is mostly straight in plan and is known as straight gravity dam. Failure of gravity dams causes and its failure modes. The highest concrete gravity dam in the world is grand dixence dam in switzerland 284 m height and bhakra dam in india 226 m 1.
Gravity dams may be classified by plan as straight gravity dams and curved gravity. By using concrete, the weight of the dam is actually able to resist the horizontal thrust of water pushing against it. For structures consisting of a section of concrete gravity dam within an. A gravity dam is an essentially solid concrete structure that resists imposed forces principally by its own weight. The most ancient gravity dam on record was built in egypt more than 400 years b. Chapter 2 includes a presentation of theory behind the key concepts of concrete gravity dams. For this purpose it is important to estimate the probability of load events and probability of failure for several failure modes. Gravity dams are constructed from masonry or concrete. Comparison of design and analysis of concrete gravity dam 19. Remnants of the malpasset concrete arch dam in frejus, france whose failure in 1959 can be partially attributed to the designs inability to accommodate uplift pressures photo source. Pdf the aim of the current paper is the assessment of the applicability of pushover analysis for a concrete gravity dam by using sap 2000 software. Damage to the dam initiates during the seismic analysis in the third step.
Failure of gravity dam occurs due to overturning, sliding, tension and compression. Pdf optimization, classical and finite element analysis. The concrete gravity dam has weight as its strength. Generally for a particular site, height of the dam is fixed as per land acquisition, reservoir size and hydro energy requirement. For structures consisting of a section of concrete gravity dam within an embankment dam, the concrete. Planning and assessment of data for project formulation. Gravity dams are designed so that each section of the dam is stable and independent of any other dam section. The integrity of the structural design requires strict adherence to specifications for the concrete and to the practice of good. Optimization of resources considering safety is one of the main challenges in an engineering problem. 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. Nonlinear time history analysis of concrete gravity dam.
This manual applies to all hqusace elements, major subordinate commands. A rollercompacted concrete dam is a concrete gravity dam constructed by the use of a dry mix concrete transported by conventional construction equipment and compacted by. Removing portions of the foundation capable of exhibiting less favorable deformation moduli and replacing with dental concrete provides some degree of beneficiation with respect to deformation modulus and is paramount in foundation preparation. This oversight was only discovered after the dam had experienced significant downstream movement. We gave a whole dam and whole course inelastic finite element simulation analysis to the dam. Gravity dams are massive structure dam which is constructed of concrete or stone masonry. Shear resistance on an existing joint in rock foundation of a gravity dam 4. Typical crosssection the basic shape of a concrete gravity dam is.
There was no efficient temperature control in the construction period of the dam so some cracks appeared in the dam. A curved gravity dam resists the external forces by its weight and not by arch action. For structures consisting of a section of concrete gravity dam within an embankment dam, the concrete section will be designed in accordance with this manual. Any structure in a reservoir, dam, or river through which water can be drawn into an outlet pipe, flume, etc. Basically, gravity dams are solid concrete structures that maintain their stability against design loads from the geometric shape and the mass and.
This cross section eventually evolved into the common triangular cross section design of todays gravity dams. In the case of an embankment dam the junction is referred to as the upstream toe of the dam. Measured and computed uplift pressures for shasta dam. It is the pressure of water that acts perpendicular on the upstream face of the dam. Based on structure and design, dams can be classified as follows. It is the highest gravity dam in the united states, and also the.
Comparison of design and analysis of concrete gravity dam. Dl51081999 design specification for concrete gravity dam. Bureau of reclamation 1976 design of gravity dams, design manual for concrete gravity dams, government printing office, washington, d. 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. Design and construction of concrete gravity dams nptel. Foundation preparation for rcc dams founded on difficult. Height is the vertical dimension from the downstream toe of the dam at. Visual examination is an essential tool by which the engineer, technician, owner or other. Gilboa dam reconstruction project summary contracts cat.
This part of water load depends primarily upon the amount of curvature. Structural stability and 2d finite element analysis of. Concrete gravity dams should be evaluated to accommodate. Concrete gravity dam is a massive structure which retains a very large amount of water on its upstream side and it is very crucial for a dam to survive against vibrations of earthquake. A cross section of this dam looks like a triangle, and the wide base is about threefourths of the height of the dam. Monitoring of uplift pressures at foundation drains within the gallery of a concrete gravity dam. Simulation of cracking in high concrete gravity dam using. The earthquake response of concrete gravity damreservoirfoundation system has been addressed to study the effect of foundation flexibility. Army corps of engineers 19581960 gravity dam design, em 111022200, government printing office, washington, d. Curved gravity dams designed for arch action and other types. A numerical prediction of crack propagation in concrete gravity dams is presented.
Using third party software to generate the geometry 26. Later gravity dams used a trapezoidal cross section. The concrete material remains elastic with no damage at the end of the second step, after the dam has been subjected to the gravity and hydrostatic pressure loads. An arch dam is a dam curved in plan and carries at major part of its water load horizontally to the abutments by arch action. Pdf assessment of the applicability of pushover analysis. Seismic structural stability of concrete gravity dams considering transient uplift pressures in cracks. Design and construction considerations for hydraulic. Concrete gravitv dams it is important for a gravity or buttress dam to maintain its structural integrity and remain stable against sliding. Pdf seismic structural stability of concrete gravity. Bureau of reclamation 1977 design of arch dams, design manual for. 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. Previous ferc gravity dam guidance dealt with nappe forces by ignoring the.
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. Numerical results are presented to illustrate the impact of various key parameters on the response of concrete gravity dams considering damreservoirfoundation interaction phenomena. Pdf comparison of design and analysis of concrete gravity dam. Gravity dam is constructed of concrete andor masonry andor laidup stone that relies upon its weight for stability. Conventional concrete and roller compacted concrete rcc are both addressed. Numerical modeling of concrete gravity dams youtube. A concrete gravity dam model is prepared in sap 2000 to perform the time history analysis.
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