Date post: | 08-Jan-2017 |
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Dams
ContentsDams & its typesRock fill damDifference b/w earth fill & rock fill
damTypes of rock fill damCross section of rock fill damClassification of earth dam.
A dam is a structure built across a stream, river or estuary to retain water.
Dams are made from a variety of materials such as rock, steel and wood.
Gravity damIt is a solid concrete structureHaving a triangular profileDesigned that it can safely stand
against the volume of water by virtue of its weight.
Concrete masonry damsrequires great quantities of material
for construction.
Gravity dam
Buttress damsButtress dams are derived from
gravity dams.Uses thin concrete slab which is
supported from downstream side by buttresses.
It uses multiple reinforced columns to support the dams.
Relatively thin structureAmount saving of concrete material
Buttress dams
Arch DamsConcrete or masonry dams which are curved
This shape helps to transmit the major part of the water load to the abutments
Commonly built across narrow, deep river gorges.
Also considered even for little wider valleys.
Arch Dams
Beavers Dam Roddents
Beavers and their dams play an important role in nature
By constructing dams they create wetlands
lush environments which Attract fish, ducks, frogs and other
creatures
Beavers Dam
Hoover DamTalles t dams
almost 700 feets high
At the base, it is an amazing 660 feet thick and at the top it is 45 feet thick
Hoover Dam
Rock fill damA rock fill dam is built of rock
fragments and boulders of large size.
The impervious zone may be on the upstream face and made of masonry, concrete, plastic membrane, steel sheet piles, timber or other material.
Rock fill damThe impervious zone may also be
within the embankment in which case it is referred to as a core.
In early rock fill dams, steel and timber membrane were also used, but now they are obsolete.
Rock fill dam
Cross section of rock fill dam
Cross section of rock fill dam
Difference of Rock fill & earth fill dam Earth fill Rock fill
01 An earth dam is made of earth soil
A rock fill dam is built of rock fragments of large size
02Earth dams are relatively
smaller in height Rock fill dams have more height than earth fill dam based on its foundation
03
They can be built on all types of foundation
Rockfill dams require foundation stronger than those
for earth dams.
04 They are mainly built with clay, sand
They are mainly built with gravel, and rocks from
mountains or river. 05 Local available soil is the
main source of construction
The material is to be collected from different
places
Classification of earth fill dams
Based on the method of construction:
Rolled fill earth dams
Hydraulic fill dam
Classification of earth fill dams
Based on mechanical characteristics of earth
materials making the section of the Dam
Homogeneous earth dams
Non-Homogeneous (zoned) earth dams
Classification of earth fill dams
Homogeneous sections are constructed with one type of soil.
The soil should have frictional resistance as well as low permeability and should be available in required quantities near site. Such sections are not in common practice.
Classification of earth fill dams
This type of dams are generally used
The casing is made of sand and gravel or soft rock etc. It provides stability to the dam section.
In the most of the dam sites, clayey silts, gravelly deposits are available and all such local materials can be used in zoned type embankments
Kalabagh Dam
References
http://animals.howstuffworks.com/mammals/beaver-dam.htm
http://www.civileblog.com/types-of-dams/
http://science.howstuffworks.com/engineering/structural/hoover-dam-broke.htm