Comparison of design and analysis of concrete gravity dam 19. A gravity dam depends on its own weight for stability and is usually straight in plan although sometimes slightly curved. Gravity dams are massive structure dam which is constructed of concrete or stone masonry. It is located in jordan on the wadi al hasa about 30km east of the dead sea and 50km south of the town of karak. The dam is composed of three blocks of equal heights. App to calculate various forces acting on a gravity dam. In this course rishikant bairwa will be discussing about the construction of dams and reservoirs. The forces, which are considered for the analysis of an.
Increasing freeboard or designing the spillway for the passage of larger flood flows. Comparison of design and analysis of concrete gravity dam. Problem 911 a concrete dam has the profile shown in figure p911. Forces acting on a gravity dams with diagram geography. Design of flood control gravity dam in wadi banban,riyadh. The junction of the upstream face of a gravity or arch dam with the foundation surface. Irrigation water resourses engineering and hydrology questions.
The upstream face may be kept throughout vertical or partly slanting for some of its length. The results show that the practical profile of gravity dam. These forces are considered to act per unit length of the dam. Height is the vertical dimension from the downstream toe of the dam at its lowest point to the top of the dam. This cross section eventually evolved into the common triangular cross section design of todays gravity dams. This project aims to design a flood control gravity dam in wadi banban in riyadh to reduce any possible flood damages. Gravity dam y910026 free download as powerpoint presentation. Difference between practical profile and elementary. First draw the profile of the gravity dam at the deepest section.
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. Introduction asically, gravity dams are solid concrete structures that maintain their stability against design loads from the. 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 section of concrete gravity dam should be chosen in such away that it is the most economic section and fulfills all the conditions and requirements of stability. Failure of gravity dam occurs due to overturning, sliding, tension and compression. Crack profiles from the analysis left in figure 1b are presented.
If you need to print pages from this book, we recommend downloading it as a pdf. 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. 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. Elementary profile of a given dam is only theoretical profile. Determination of various forces which acts on the structure is the first step in the design of dams. The elementary profile of a dam, subjected only to the external water pressure on the upstream side, will be rightangled triangle, having zero width at the water level and a base width b at bottom, i. Later gravity dams used a trapezoidal cross section.
Elementary profile of a gravity dam when the reservoir is full, the base width is governed by. The forces, which are considered for the analysis of an elementary profile of a gravity dam under empty reservoir condition, are. 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. Tech civil engineering final year last semester numerical on gravity dam video link. Finite element has been widely used in seismic analysis of concrete gravity dams utilizing the most natural method based on the lagrangianeulerian formulation. Gravity dam is constructed of concrete andor masonry andor laidup stone that relies upon its weight for stability. Although theamount of cement required is largerthan in the previous methods,itscost is more thanoffset. Dams exercise problem 1 a concrete gravity dam 15 m height will be constructed with the dimensions shown in the figure below. Conventional concrete and roller compacted concrete are both addressed. Mark the height of the maximum water level on the upstream side and the maximum water level on the downstream side.
How to calculate the uplift pressure on a gravity dam quora. Gravity dam design united states army corps of engineers. Elementary profile of stress intensities stability analysis merits and demerits of 4. Elementary profile of a gravity dam the elementary profile of a dam, subjected only to the external water pressure on the upstream side, will be rightangled triangle, having zero width at the water level and a base width b at bottom, i. Elementary profile of a dam subjected only to external water pressure on upstream side, will be right angled triangle, having zero width at water level and a base width b at bottom, i. Elementary profile of gravity dam 1 in hindi unacademy. By using concrete, the weight of the dam is actually able to resist the horizontal thrust of water pushing against it.
Ppt gravity dam powerpoint presentation free to view. Gravity dam is so proportioned that its own weight resists the forces acting upon it. Forces on gravity dam irrigation engineering youtube. Gravity essentially holds the dam down to the ground, stopping water from toppling it over. Fracture analysis of concrete gravity dam under earthquake induced. Forces acting on a gravity dam, causes of failure of a gravity dam, elementary profile and practical profile of a gravity dam, limiting height of a low gravity dam, factors of safety. Gravity dams a gravity dam is one which depends entirely on its own mass for stability figure 4. Gravity dams are designed so that each section of the dam is stable and independent of any other dam section. Let the dam extend 300 m from the us edge to the ds edge, in th. Tannur dam is a 60m high, 250m long roller compacted concrete rcc gravity dam with a reservoir capacity of 17 million cubic metres. Design and construction of concrete gravity dams nptel. The stability conditions required to investigate for concrete gravity dam, subjected just to its selfweight w, force resulting from water. The design of gravity dams is then, of necessity, based upon a number of simplifying assumptions, perhaps the most important of which is to consider the problem in two dimensions and limit calculations to finding the stress distribution on a cross section at right angles to the longitudinal axis of the dam. Keywordschromosomes, dam, genetic algorithm, global optimum, preliminary layout, stress analysis, theoretical profile.
These additions of two provisions will cause the resultant force to shift. Construction as a site with a nar row canyon profile on sound bedrock close to the surface is preferable, as this location would minimize the. Certain changes have to be made in this profile in order to cater practical needs. The basic gravity profile is triangular in shape, but for practical purposes, is modified at the top. 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. Water resources engineering ii notes pdf wre ii notes pdf file water resources engineering ii notes pdf wre ii pdf notes wre ii notes pdf. Types of gravity dam a gravity dam is a structure so proportioned that its own weight resists the forces exerted upon it.
Concrete and masonry dams the national academies press. A detailed sketch of a gravity dam is shown in fig. Slope layer method for the construction of rcc dams pdf. In the case of an embankment dam the junction is referred to as the upstream toe of the dam. Gravity dams are constructed from masonry or concrete. Introduction types of dams characteristics of dams reservoir planning 7. Storage dam diversion dam coffer dam power generation dam concrete gravity dam.
The resultant of all the downward forces will represent the total weight of the dam acting at the center of gravity of the dam. Reservoir capacity allocation sheet used by bureau of reclamation. Gravity dams are well suited for blocking rivers in wide valleys or narrow gorge ways. Adi forces acting on gravity dam ce in hindi youtube. These dams are most permanent ones, requires little maintenance and is most commonly used. A gravity dam is a structure so proportioned that its own weight resists the forces exerted upon it. The first version of a modern gravity dam was built between 1765 and 1800 in mexico.
Stable channel hydrology and geology topography, geology, sociology. The following is a list of terms and their definitions that are frequently used when discussing the. The main actions, such as self weight and hydrostatic pressure, but also uplift, were fairly well studied in this period. Elaidi and hall 1989 did a research on seismic fracture of pine flat dam. It is intended to implement an internal drainage facility, which would reduce uplift pressure by about 20%. Multiple step method of design of gravity dam and comparison with cadam software. 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.
Failure of gravity dams causes and its failure modes. All the predominant forces that act on the dam have been shown in the figure itself. Water resources engineering ii notes pdf wre ii notes pdf. An example design of small african journals online. Reservoir silt can reduce uplift under a dam in a manner similar to an upstream apron. Different types of forces acts on a dam structure such as water pressure, self weight, wave pressure etc. Pdf multiple step method of design of gravity dam and. Curved gravity dams designed for arch action and other types of concrete gravity dams are not covered in this manual. If the density of concrete is 2400 kgm 3 and that of water is kgm 3, determine the maximum compressive stress at section mn if the depth of the water behind the dam is h 15 m. A drainage gallery is generally provided in order to relieve the uplift pressure exerted by the seeping water.