types of dam

this slide shows different types of dams, their sizes and short information of dams.following dams are explained in this slide which are given below masonry dam, concrete dam, arch dam,earthen dam. this slide also shows types of material required for dam, strength, hight

1. TYPES OF DAM AKSHAY SHINDE

2. INTRODUCTION TYPES OF DAMS STRUCTURE OF DAM PRELIMINARY INVESTIGATION SITE SELECTION F0R DAM FACTORS AFFECTING ON DAM PURPOSES OF DAM FAILURE OF DAM CONCLUSION REFERENCES CONTENTS

3. WHAT IS DAM ? A dam is a barrier constructed across a river or a natural stream to create a reservoir for impounding water or to facilitate diversion of water from the river. At back side of this barrier water gets collected, forming a pool of water, the side on which water gets collected is called as upstream side and the other side of barrier is called as downstream side. The lake of water which is collected on upstream side of dam is called as a reservoir . Dam is a very large structure, generally length is about half kilometer constructed across the river to storage a water for many purposes like, irrigation, industrial supply, hydropower, recreation etc. INTRODUCTION

4. Generally, the dam should be constructed of ‘V’ shape thus to achieve economy in it’s construction. The tallest dam in the world is ‘NUREK DAM’ in Tajikistan has 300m high and the ‘BHAKRA DAM’ is the highest in Asia and second highest in the world. The BHAKRA dam is constructed across river SULTEJ in Himachal Pradesh and has 246m high, the construction of this dam was started in the year 1948 and was completed in 1963. RAW MATERIALS : Dams may be constructed of raw materials like, masonry, timber, steel, gravel, clay, sand and silt etc.

5. The type of dam depends upon the condition of dam site, the main Type of dam are as follows :- Earthen dam Gravity dam Arch dam Buttress dam TYPES OF DAM

6. The dams which are constructed of earthen materials such as gravel sand, silt and clay are called as ‘ Earthen Dam’. They are ‘trapezoidal’ in shape. Earthen dams are relatively smaller in height and broad at the base. Earthen dams are constructed where the foundation or the underlaying materials or rocks are weak to support the masonry dam or where the suitable competent rock are at greater depth. EARTHEN DAM

7. Gravity dam is a solid structure made up of masonry or concrete and are constructed across the river to resist the forces exerted upon it by it’s own weight. These dams are heavy and massive wall like structures of concrete in which the whole weight act vertically downwards. As the entire load is transmitted on the small area of foundation, such dams are constructed where rocks are competent and stable. Example :- ‘BHAKRA DAM’ is the highest concrete gravity dam. GRAVITY DAM

8. These types of dams are constructed of concrete or masonry dams which are curved or convex upstream in plan. This shape helps to transmit the major part of the water load to the abutment. Arch dams are built across narrow, deep river gorges, but now in recent years they have been considered even for little wider valleys. ARCH DAM

9. ‘Buttress’ means a support that transmits a force from a roof or wall to another supporting structure. Buttress dam is a gravity dam reinforced by structural supports. This type of structure can be considered even if the foundation rocks are little weaker. BUTTRESS DAM

10. STRUCTURE OF DAM

11. HEEL :- Contact with the ground on the upstream side. TOE :- Contact on the downstream side. ABUTMENT :- Sides of the valley on which the structure of the dam rest. GALLERIES :- A gallery is an opening provided in a dam for obtaining access to the interior of dam. SPILLWAY :- It is the arrangement near the top to release the excess water of the reservoir to downstream side. SLUICE WAY:- It is an opening in the dam near the ground level, which is used to clear the silt accumulation in the reservoir side. FREE BOARD :- It is the vertical distance between top bund level and high flood level.

12. To do all preliminary survey like engineering, hydrological, geological and detailed survey etc. To collect the report about maximum height of flood level by past 35 years at dam site. To know the soil condition and bearing capacity, to decide the type of dam to be constructed at dam site. To collect the information about people getting benefit from the dam and maximum area is to be irrigated by the dam. To know the maximum annual rainfall at the dam site. PRELIMINARY INVESTIGATION

13. Good foundation should be available. It should be located in a narrow valley. It should have sufficient space for spillway. It should fulfill the purpose i.e. irrigation, drinking etc. Material should be easily available near by site. It should be easily accessible throughout the year. SITE SELECTION FOR DAM

14. Funds available Topography Availability of materials Nature of foundation Spillway position Height of dam Earthquakes FACTORS AFFECTING AT DAM SITE

15. Dams are constructed for following purposes :- Irrigation Hydropower generation Water supply Flood control Recreation Industrial water supply PURPOSE OF DAM

16. The cause may be occur due to the following reasons :- Poor surveying Spillway design error Extreme rainfall Due to earthquakes Human, computer or design error Poor maintenance FAILURE OF DAM

17. From above this it is clear that , before constructing dam the site selection and preliminary investigation is very important factor while designing the dam and the selection of type of dam are also depending on the soil condition at dam site. CONCLUSION