Dam - Classification based on structure

including selection of sites and Dam failure

1. HERITAGE INSTITUTE OF TECHNOLOGY Department - CIVIL Presented by- Abhijit Pal TOPIC - DAM

2. OUTLINE What is a Dam Structure of Dam Purposes of Dam Selection of Dam sites Classification of Dam On structure Dam failure Disadvantages of Dams Conclusion Bibliography

3. WHAT IS A DAM A Dam is an obstruction or barrier built across a steam or river It is a structure built to retain water

4. STRUCTURE OF DAM Heel - contact with the ground on the upstream side Toe – contact on the downstream side Sluiceway - An opening in the dam near the ground level, which is used to clear the silt accumulation in the reservoir side

5. STRUCTURE OF DAM Spillway – It is the arrangement near the top to release the excess water of the reservoir to downstream side Gallery - S mall rooms like structure left within the dam for checking operations Abutment - Sides of the valley on which the structure of the dam rest

6. PURPOSES OF DAM Water supply - Dams gather drinking water for people Flood control - Dams keep areas from flooding Irrigation - Dams help farmers bring water to their farms Hydroelectric - Dams help create power and electricity from water Navigation - Dams create lakes for people to sail on from one part to another Recreation - Dams can be used for swimming

7. PURPOSES OF DAM

8. SELECTION OF DAM SITES Topography Geology Material availability Spillway size and location Communication Locality land and population

9. CLASSIFICATION OF DAM ON STRUCTURE Arch Dam Gravity Dam Buttress Dam Embankment Dam

10. ARCH DAM An A rch Dam is a curved dam built where access to materials is limited Ex- Idukki Dam in Kerala Arch Dams are thinner and therefore require less material than any other type of dam These are dependent upon arch action for its strength

11. ARC DAM

12. GRAVITY DAM Gravity D ams resist the horizontal thrust of the water entirely by their own weight Ex- Dworshak Dam in Idaho Gravity Dams are typically used to block streams through narrow gorges

13. GRAVITY DAM

14. BUTTRESS DAM Buttress Dams are dams in which the face is held up by a series of supports Ex- Bartlett Dam in Arizona Most B uttress Dams are made of reinforced concrete and are heavy, pushing the  dam  into the ground

15. BUTTRESS DAM

16. EMBANKMENT DAM Embankment Dams are massive dams made of earth or rock Ex- Tataragi Dam in Japan Typically created by the placement and compaction of a complex mound of various compositions of soil, sand, clay and/or rock

17. EMBANKMENT DAM

18. DAM FAILURE Faults in construction methods   eg-Teton Dam in Idaho, USA in 1976 Geological problems with the dam foundation eg -  St.Francis dam Landslides which fall into the storage reservoir eg -  Vaiont Dam in Italy in 1963

19. DAM FAILURE Earthquakes can certainly cause damage to dams eg -Lower San Fernando Dam Dangerous alterations to the operation of the dam and/or its structure may lead to failure eg - South Fork Dam (Johnstown) in 1889

20. DISADVANTAGES OF DAMS The natural environment is destroyed The building of large dams can cause serious geological damage Dams have endangered some species of fish, inhibited the seasonal migration of fish Displaces people

21. CONCLUSION Dams support 30%-40% of the irrigated area and 12%-16% of the global food production Thus dams can be a source of huge profit both in terms of fresh water resource and generation of electric power Therefore construction of dams should be made keeping in mind its long terms of service

22. BIBLIOGRAPHY Engineering Geology by Parbin Singh www.dams.com www.google.com/dams