The cross section is rotated 150and the axis of rotation is 150 feet. The assumptions made are not strictly true so the effect of. Jan 28, 2014 the variable radius arch dam is an intermediate choice, using 58 % of the concrete used by constant radius arch dam. A type of doublecurved arch dam is adopted considering the ushaped valley with a bottom width of 7086 m. One, the jones falls dam, was a true arch dam legget 195759, smith 1971, schnitter 1994.
For this purpose 203m dez arch dam is selected as case study and the finite element model of dam reservoirfoundation system is excited in various performance levels. In the 20th century, the worlds first variableradius arch dam was built on the salmon creek. Arch dams are suited for relatively narrow valleys with competent rock in the abutments. Seismic assessment of arch dams using fragility curves. Seismic assessment of arch dams using fragility curves in the present paper, the ida approach is applied to analyzing a thin high arch dam. Typically the angle subtended by the arch at the crest is between 90 and 120. An arch dam having a curved surface transfers the forces acting on it laterally to the foundation. This video clip gives an overview on new working environment in diana 9. To form an arch dam, the cross section described in this labs data is swung through an arc, rotating it about the yaxis as shown in the figure below. Shape optimization of concrete arch dams considering stage. Dynamic modelling of arch dams in the ambient state. In the case of gravity dam, the dam s self weight is used to resist the forces acting on it. Length, thickness, and central angle of arch at crest of dam.
A constant radius arch dam is the one in which the radius of the extradosor outside curved surface of the arch is constant at all elevations from top of the dam to its base. An arch dam which is curved vertically as well as horizontally. The handbook of dam engineering 1 presented the subject of concrete dam design from fundamental definitions of terms through planning, design, and construction considerations. Arch gravity dams are massive dams of concrete that resist the thrust of water by their weight using the force of gravity and the arch action an arch gravity dam incorporates the arch s curved design that is so effective in supporting the water in narrow, rocky locations where the gorges sides are of hard rock and the water is forced into a narrow channel. Theoryofdesignofarchdnns 30 athetheoreticalarch 51 btheeconomicradius 31 2. It is a dam that curves upstream in a narrowing curve that directs most of the water pressure against the canyon rock walls, providing the force to compress the dam. Nevertheless, one of the most important investigations in the field of shape optimization of concrete arch dams carried out by bofang, z. The constant radius arch design, also called the single radius arch, is a cylindrical shape fig. A water resources technical publication united states department of the interior, bureau of reclamation, bw illustrations, charts on. The arch dam is designed so that the force of the water against it, known as hydrostatic pressure, presses against the arch, causing the arch to straighten slightly and strengthening the structure as it pushes into its foundation or abutments. The upstream face is usually vertical while the downstream face is battered. The salmon creek dam is a concrete arch dam on the salmon creek, 3 miles 5 km northwest of juneau, alaska.
Arch crown cantilever is the highest beam in arch dam, such as fig. Definition of geometry of variable radius arch dam with. Case studies of a typical cylindrical arch dam and the wudongde arch dam demonstrate the robustness and feasibility of the proposed method. Shape optimal design of arch dams including damwater. In progress design of doublecurvature arch dams planning. The equation of the parabola ab with vertex a0,a1 and radius r is.
The analysis of stresses and design of multiplearch dam. Nonlinear design and safety analysis of arch dams using. It is important that a dam owner be aware of the different types of dams, essential component parts of a dam, important physical conditions likely to influence the dam, and how the key components function. Local cracking stability analysis of super high arch dam.
Classification of an arch dam depends on its angle, radius and curvature. In essence, the amount of material in or the mass of a structural dam is a. However the intrados or inside curved surface of arch has gradually decreasing radius as the depth below the crest increases,to provide the increased thickeness needed. Verification of the response of a concrete arch dam. In the latter, seismic loads, damfoundation reservoir interaction have been considered and method is applied successfully in shahid rajaee arch dam in iran. In essence, the amount of material in or the mass of a structural dam is a less important attribute than it is for a massive dam. In the case of gravity dam, the dams self weight is used to resist the forces acting on it. Thickness and upstream projection at base of crown cantilever. With the handbook and other wellaccepted references as background, this chapter takes the opportunity to discuss areas of new and updated technology. Length and central angle of lowest theoretical arch in analysis. Arch dams are usually built in narrow, deep gorges in mountainous regions where access and availability of construction materials pose especially acute problems. Oo m so 70 so so 40 so so,oo 400 so00 pooo notes dlmonsions roquirod for using shotis h sestimotod structural height of dam from crest to bore including assumed depth of excavation.
Most of that information is still pertinent and usable. A note on the search for optimal shapes of arch dams. Guide for preliminary design of arch dams by howard l. The geometric expression of right bank is the same as expression of left bank, the difference is simply that the x value of right bank is negative value. Double curvature arch dam the term double curvature arch dam as it applies to the area of reclamation can be defined as an arch dam which is curved in plan and elevation, with undercutting of the heel and in most instances, a downstream overhang near the crest. The geometry of the arch dam is described in the cartesian. In the case of arch dams, the maximum nodal displacement on the crest and the total lateral reactions of the dam body seem to be the desired coordinate system, and has been chosen in this work. Stanford libraries official online search tool for books, media, journals, databases, government documents and more. For this purpose 203m dez arch dam is selected as case study and the finite element model of damreservoirfoundation system is excited in various performance levels. Constant radius arch dam a constant radius arch dam is an arch dam, the arch centre of which for the upstream face, the downstream face and the centre line are all coincident with the axis centre at all elevations. Eigen value analysis of an arch dam diana dams 9 6 youtube. Built in 1914, it is the worlds first constantangle arch variable radius dam.
Oct 19, 2012 thinarch dam for a wide u shaped canyon morrow point dam showing the progression from layout through design appendix j1. Also known as chord and sagitta or versine calculation. Developed layouts and designs of singlecentered uniformthickness doublycurved arch dam for a verywide v shaped canyon upper san joaquin dam showing the progression from layout through design appendix j2. It combines the strengths of two common dam forms and is considered a compromise between the two. Was widely used in the past when arches were the main loadbearing. Thickness at the base of the crown cantilever is typically 15 to 25 percent of the height.
At 186 metres 610 ft in height, it is the tallest dam in japan. Arch calculation for layout find radius, given span and. The discretized structural dynamic equation including the arch dam and foundation rock subject to ground motion can be formulated using the finiteelement approach as. The basic arch dam shapes are the constant radius arch, the constant angle arch and the doublecurvature arch with increasing complexity. Use your explanation to calculate the volume of the arch dam. Xiluodu arch dam is an under construction super high arch dam situated on the jinshajiang river in yongshan county, yunnan province, southwest china. The structural designer should select a value for the radius of the dam axis raxis. The constant angle arch dam is a special type of variable radius arch dam, in which the centeral angles of the horizontal arch rings are of the same magnitude at all elevations. Scholar, university of calicut, kerala, india 2 former principal, govt. Because of this arch action, the thickness and hence bulk of the dams profile can be much less than a gravity dam of the same height. The height and the crest length of the dam are 100 and 200 m, respectively as we know c oncrete arch dam is a solid structure. Variable radius dams have upstream and downstream curves extrados and intrados curves of systematically decreasing radii with depth below the crest.
Multiplearch dam article about multiplearch dam by the. Definition of geometry of variable radius arch dam with degree of polynomial in the 3d finite element analysis susan abraham1, k. Safe and best central angle 3 0 34 is used as central angle in this case. Dez dam is located at 20 km ne of andimeshk, khuzestan, iran figure 6a. Arch dams can be designed with a constant or a varying radius. The parameters of sa, pga and pgv are used as intensity measure im and the overstressed area osa is utilized as engineering demand parameter edp and then, three limit states are assigned to the. Mathematical modeling and numerical analysis of thermal. Uplift is not usually of importance in thin arch dams, but in thick arch dams provision is made for internal drainage, as for gravity dams. The cross section is rotated 150 and the axis of rotation is 150 feet. Optimization design of arch dam shape with modified. The optimized workflow in conjunction with unique and intuitive features opens a new paradigm in modeling and analysis of. Those portions directed toward arch dam design are still relevant for new dam design and the evaluation and rehabilitation of existing dams. Constant radius arch dams commonly have a vertical upstream face with a constant radius of curvature. It is obtained by the modification of variable radius arch dam.
Guide for preliminary design of arch dams mo ii00,000 000 so0 700 sw so0. The11quid pressure on the arch barrel exerts a radial. Since it was built, over 100 such dams have been constructed all over the world. Boggs division of design office of design and construction. They used a commercial program for finite element analysis and dot as an optimizer. The geometry of the arch dam is described in the cartesian dam coordinate system x0,x1,x2. The arch radius at the crest is typically between 1 and 2 times the height of the dam.
An archgravity dam or arched dam is a dam with the characteristics of both an arch dam and a gravity dam. Hazards, risk, failures present national loss statistics from dam failure fully justify the need for dam owners to better. Explain how you would calculate the volume of the arch dam. The maximum height of the arch dam is 109 m, with its dam crest being 176.
Thickness at the base of the crown cantilever is typically 15. The crest elevation required for the dam should be known at this time from hydrologic data and this, in conjunction with the elevation of the streambed or assumed foundation elevation at the general location of the dam, determines the dam height, h feet. An arch dam is a concrete dam that is curved upstream in plan. Optimization design of arch dam shape with modified complex. The results indicated that the concrete volume of the arch dam optimized by the. The dam height is 203 m from the foundation and 190 m from the river bottom.
An arch dam transfers loads to the abutments and foundations both by cantilever action and through horizontal arches, and a method of distribution was developed by stucky in switzerland and the usbor. An arch dam is most suitable for narrow canyons or gorges with steep walls of stable rock. Draw a circular arc with radius raxis on a piece of tracing paper at the same scale as the topography map. Moreover, using the fem, the nodal load of the arch dam can be easily obtained. When foundations are solid rock normally concrete gravity dam is constructed. Seismic analysis of double curved arch dams based performance. The dam is still used today for hydropower and navigation purposes. The design of such a dam can, thus be made by adopting best central angle of 3 degrees and 34 minutes. Built in 1914, it is the worlds first constant angle arch variable radius dam. Constant angle arch dam, is a dam in which central angle of every arch ring is constant throughout the height of an arch dam. A constant radius arch dam is the one in which the radius to some prominent feature such as upstream face, or the downstream face, or the arch axis is constant. This dam is considered as a thin double curvature arch dam.
When a dam is also doubly curved, that is, it is curved in both. The variable radius arch dam is an intermediate choice, using 58 % of the concrete used by constant radius arch dam. Contributions of flexiblearch configurations in shimenzi. In most cases, however, the constant radius refers to the upstream side. The dam is a concrete double curvature arch with a maximum height of 285. When the abutments are also of solid rock and the gorge is narrow like v shape, it is desirable to go for concrete arch dam. Optimum design of double curvature arch dams using 229 subject to. Its use in thin arch dams is favoured, however for a 90m high dam the cost of reinforcement will be many millions of dollars, which could mitigate the adoption of such a dam. General displacement archcantilever element method for.