HERITAGE INSTITUTE OF TECHNOLOGYDepartment - CIVIL

Presented by- Abhijit Pal

TOPIC - DAM

OUTLINEWhat is a DamStructure of Dam Purposes of DamSelection of Dam sitesClassification of Dam

On structure Dam failureDisadvantages of DamsConclusionBibliography

WHAT IS A DAMA Dam is an

obstruction or barrier built across a steam or river

It is a structure built to retain water

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

STRUCTURE OF DAMSpillway– It is the

arrangement near the top to release the excess water of the reservoir to downstream side

Gallery- Small rooms like structure left within the dam for checking operations

Abutment- Sides of the valley on which the structure of the dam rest

PURPOSES OF DAMWater supply- Dams gather drinking water for

peopleFlood control- Dams keep areas from floodingIrrigation- Dams help farmers bring water to their

farmsHydroelectric- Dams help create power and

electricity from waterNavigation- Dams create lakes for people to sail

on from one part to anotherRecreation- Dams can be used for swimming

PURPOSES OF DAM

SELECTION OF DAM SITESTopographyGeologyMaterial availability Spillway size and locationCommunication Locality land and population

CLASSIFICATION OF DAMON STRUCTURE

Arch DamGravity DamButtress DamEmbankment

Dam

ARCH DAMAn Arch Dam is a curved

dam built where access to materials is limited

Ex- Idukki Dam in KeralaArch Dams are thinner

and therefore require less material than any other type of dam

These are dependent upon arch action for its strength

ARC DAM

GRAVITY DAMGravity Dams 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

GRAVITY DAM

BUTTRESS DAM• Buttress Dams are

dams in which the face is held up by a series of supports

• Ex- Bartlett Dam in Arizona

• Most Buttress Dams are made of reinforced concrete and are heavy, pushing the dam into the ground

BUTTRESS DAM

EMBANKMENT DAMEmbankment 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

EMBANKMENT DAM

DAM FAILUREFaults 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

DAM FAILUREEarthquakes 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

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

CONCLUSIONDams support 30%-40% of the irrigated area

and 12%-16% of the global food productionThus 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

BIBLIOGRAPHY

Engineering Geology by Parbin Singhwww.dams.comwww.google.com/dams