Stability analysis of gravity dam using staad pro youtube. Failure of gravity dams causes and its failure modes. Therefore, for stress analysis of the dam foundation system of gravity dams, the series combination creep model is applied for the first onethird of dam height from the base and the parallel combination creep model is applied. Gravity dam a gravity dam has been defined as a structure which is designed in such a way that its own weight resists all the external forces. Material used in its construction was the solid blocks of concrete. A gravity dam is an essentially solid concrete structure that resists imposed forces principally by its own weight.
Pdf structural analysis of a gravity dam using finite elements. In traditional deterministic analysis, equal safety coe cient method namely, equal methodisusedtoanalyzeandassessthe. Limiting height of gravity dams, as well as considerations on low and high gravity dams b. Gravity dam, concrete, moments, frictional force, stability, staad pro v8i introduction.
Measured and computed uplift pressures for shasta dam. Computer aided stability analysis of gravity damscadam. The modeling and subsequent analysis of the dam has been carried out on. Analyses of mechanical, thermal and filtration processes in the large gravity dam and surrounding rock mass were performed and presented. Previous ferc gravity dam guidance dealt with nappe forces by ignoring the. Froces acting on concrete gravity dam technically a concrete gravity dam derives its stability from the force of gravity of the materials in the. Work out the magnitude and dimensions of all the vertical forces acting on the dam and their algebraic sum, i. The last one is the general case for analysis of foundation instability of gravity dam by assuming the potential failure surface as shown in figure 1. 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.
The upstream face may be kept throughout vertical or partly slanting for some of its length. This manual applies to all hqusace elements, major subordinate commands. This paper presents the basic guideline for stability analysis of concrete gravity dam. The gravity dam has to maintain its stability against the l oads from its structural mass and strength of concrete. The dam may also be prevented from sliding by keying its base into the bedrock. Usually concrete gravity dams are constructed across a river by excavating away the. The coupling is done using the interfaces that take into account the interaction forces between the dam and soil. Conclusions are drawn regarding the effect of joint normal stiffness on the behavior of gravity dams due to seismic loads. Structural analysis of concrete dams, spillways, intake towers, outlet works, gates, valves, etc. Response spectrum analysis of concrete gravity dams including damwaterfoundation interaction arnkjell lokke department of structural engineering norwegian university of science and technology ntnu anil k.
Pdf design and analysis of concrete gravity dams researchgate. Design criteria for co arch and gr vity dams united states department of the interior. A gravity dam may fail by the failure of its material, i. Mar 04, 2014 for the love of physics walter lewin may 16, 2011 duration.
Masonry gravity dams a numerical application for stability analysis figure 2 show the loads involved in gravity dams analysis, namely. The compressive stresses applied to a gravity dam are usually fairly low, and below the. Chapter iii gravity dams 30 contents title page 31 purpose and scope 31 31. Gravity dams are designed so that each section of the. Model of concrete gravity dam for non linar time history analysis the model of the dam is prepared in sap 2000 itself. Research article application of probabilistic method to. This work presents a numerical application for stability analysis of masonry gravity dams. The analyses were conducted within the stability analysis of the dam djerdap 1. The crosssection can be divided into rectangles and triangles. This is conducted by determining the limit states and seepage of the dam. With the aid ofdynamic response analysis, considering the effects ofinteraction between the dam and impounded water and ofwater compressibility, it has been demonstrated.
In the simplified method for seismic analysis of concrete gravity dams, the hydrodynamic forces arising from the fundamental mode of vibration are calculated and applied to the upstream face of the dam as an equivalent static load chopra, 1978. The sliding patterns of gravity dam foundation could be divided by slip paths over single, dual, and multiple planes. Analysis and design of gravity dam in seismic zone v project by. Effect of soil structure interaction on gravity dam. Certain techniques are evolved to take account of the openings in the structure even in a twodimensional analysis. The stability of a dam can be analysed in the following steps.
Finite element analysis of gravity dam with drainage gallery. The gravity method of the analysis does not consider the size of opening and the elastic property of dam material. This oversight was only discovered after the dam had experienced significant downstream movement. Therefore, for stress analysis of the dam foundation system of gravity dams, the series combination creep model is applied for the first onethird of dam height from the base and the parallel combination creep model is applied to the rest. Methods of analysis used to design arch and gravitytype concrete dams should. Drainage gallery is very critical in case of gravity dam. The model comprises of two parts namely the concrete dam and the foundation rock. Response spectrum analysis of concrete gravity dams including. Comparison of design and analysis of concrete gravity dam.
Jan 28, 2014 gravity dam weight of the dam the weight of the dam body and its foundation is the major resisting force. Through analyzing concrete gravity dam structures mechanical characteristics in construction process and operating process, this paper adopts finite element method to carry out structural analysis. Stability analysis of gravity dams for the maximum. Nonlinear time history analysis of concrete gravity dam. In two dimensional analysis of a gravity dam, a unit length of the dam is considered. This dam was used in usace to evaluate and compare stability analysis and uplifting criteria for gravity dams by three us federal. A gravity dam is mostly straight in plan and is known as straight gravity dam. Introduction a typical crosssection of a gravity dam is the upstream face may kept throughout vertical or partly slanting for some of its length. Stability analysis of concrete gravity dam an overview. As we know gravity dam is a solid masonry structure,8 nodded solid elements and shells as a plates are provided to the dam make it solid structure combination of shell elements and solid element is used. Dam dam is a solid barrier constructed at a suitable location across a river valley to store flowing water.
Gravity dam loads on concrete dams loads can be classified in terms of applicabilityrelative importance as primary loads, secondary loads, and exceptional loads. On the basis of threedimensional 3d fem, the dam structure and base of gravity dam of gu county reservoir is analyzed and the stress and displacement is calculated in this paper. Nonlinear time history analysis of concrete gravity dam by. The dams include concrete gravity dams, concrete arch dams single and double curvature, concrete buttress and multiple arch dams seismic and dynamic response analysis natural. As consequences of dam failure are devastating, the failure modes and seepage of the dam needs to be analyzed. Similarly work out all the horizontal forces and their algebraic sum i. A curved gravity dam resists the external forces by its weight and not by arch action. Gravity dam is constructed of concrete andor masonry andor laidup stone that relies upon its weight for stability.
Stability analysis of concrete gravity dam a n overview. Masonry gravity dams a numerical application for stability. The model of the dam is prepared in sap 2000 itself. Gravity dam weight of the dam the weight of the dam body and its foundation is the major resisting force.
Pdf dams have been constructed for millennia, influencing the lives of humans and the ecosystems they inhabit. When the resultant lies outside the middle onethird, tensile stresses are. Three scenarios are considered normal water condition, c ritical water condition and an earthquake hitting the normal water scenario. 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. Flow chart for the analysis of gravity dam 1 consider unit length of the dam. A gravity dam is a solid structure, made of concrete or masonry, built throughout a river to create a reservoir on its upstream. Analysis of gravity dam fluid mechanics and hydraulics. Diagrams of base pressures acting on a gravity dam. Stability evaluation of gravity concrete structures dams, retaining walls. Modelling and apply pushover and cyclic load test on beam column by abaqus and get hysteresis loop duration. The gravity method of analysis requires that the resultant of all forces acting on the dam lie within the middle onethird of the base to avoid tensile stresses at the heel. The presence of water in the reservoir is simulated through hydrostatic and hydrodynamic stresses. For the love of physics walter lewin may 16, 2011 duration. The segment of the gravity dam is approximately triangular in shape, with its apex at its pinnacle and most width at backside.
Description of forces acting on the dam, and its analysis. Gravity dam design united states army corps of engineers. Structural analysis of a gravity dam using finite elements. Later gravity dams used a trapezoidal cross section. Ppt gravity dam powerpoint presentation free to view id. Conventional concrete and roller compacted concrete rcc are. Application of probabilistic method to stability analysis. Any stability analysis of the dam should s eek to apply forces that are compatible. Design and construction of concrete gravity dams nptel. Seismic response of a concrete gravity dam considering.
The result indicates that a majority of dam is in the stress state and stress concentration exits in. Structural stability and 2d finite element analysis of concrete gravity dam. Which was the type known as osolid masonry gravity dam. By using concrete, the weight of the dam is actually able to resist the horizontal thrust of water pushing against it. 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. The second modern dam of the world was roosevelt dam constructed on the salt river of arizona u. The weight of gravity dam will cause a moment opposite to the overturning moment and the friction on the base will prevent the dam from sliding. Comparison of design and analysis of concrete gravity dam 19. The pressure due to this seepage is commonly called hydrostatic uplift and will reduce the stability of the dam against sliding and against overturning.
Ppt gravity dam powerpoint presentation free to view. Response spectrum analysis of concrete gravity dams. The earthquake analysis ofconcrete gravity dams has come a long way, progressing from traditional static methods for computing design forces to dynamic analysis procedures. Pdf structural analysis of a gravity dam using finite. In terms of strain, this relationship can be expressed as. Finite element analysis of gravity dam with drainage. In the formulation of the dam and soil interaction, a substructure method is used. In this method, the dam is considered to be composed of parallel sided vertical cantilevers. Shear resistance on an existing joint in rock foundation of a gravity dam 4. Curved gravity dams designed for arch action and other types of concrete gravity dams are not covered in this manual. The most ancient gravity dam on record was built in egypt more than 400 years b. This cross section eventually evolved into the common triangular cross section design of todays gravity dams.
This manual presents analysis and design guidance for concrete gravity dams. A drainage gallery is generally provided in order to relieve the uplift pressure exerted by the seeping water. Dec 17, 2017 modelling and apply pushover and cyclic load test on beam column by abaqus and get hysteresis loop duration. The stresses throughout the dam are computed using the. The first version of a modern gravity dam was built between 1765 and 1800 in mexico. The dams include concrete gravity dams, concrete arch dams single and double curvature, concrete buttress and multiple. Gravity essentially holds the dam down to the ground, stopping water from toppling it over.
When the resultant lies outside the middle onethird, tensile stresses are assumed to develop along the base of the dam. The following are the various methods which can be adopted for carrying out the stability analysis of gravity dams. Stability analysis of nonoverflow section of concrete. Structural stability and 2d finite element analysis of. Numerical modeling of concrete gravity dams youtube. The results show that the proposed progressive methodology, is a beneficial procedure to. Therefore, for stress analysis of the damfoundation system of gravity dams, the series combination creep model is applied for the first onethird of dam height from the base and the parallel combination creep model is applied to the rest. Height is the vertical dimension from the downstream toe of the dam at its lowest point to the top of the dam. The analytical results obtained from over twenty 2d finite element modal analysis of concrete gravity dam show that the. This method of stability analysis is also sometimes known as two dimensional methods. Gravity dams are the lifesaving mega structures which are mainly used for irrigation, hydroelectric power generation, water supply, water animal.
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