What is size if drainage holes of gravity dam as 6512-1984?
Answers
Answer:
Design Criteria
of
Gravity Dams
Analysis and design of Concrete Dams
As per structural behaviour:
Gravity dams
Buttress dams
Arch dams
Classification of Concrete Dams :
Analysis and Design of Concrete Dams
EarthDams
:
They are trapezoidal in
shape
Earth dams are constructed
where the foundation or
the underlying material or
rocks are weak to support
the masonry dam or where
the suitable competent
rocks are at greater depth
.
Earthen dams are relatively
smaller in height and broad
at the base
They are mainly built with
clay, sand and gravel, hence
they are also known as
Earth fill dam or Rock fill
dam
Heel
Gallery
Toe
Crest
NWL
Normal
water level
MWL
Max. level
Free board
Sluice wa
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: small rooms like structure left within the dam for checking
operations.
Diversion tunnel: Tunnels are constructed for diverting water before the
construction of dam. This helps in keeping the river bed dry.
Spillways: It is the arrangement near the top to release the excess water
of the reservoir to downstream side
Sluice way: An opening in the dam near the ground level, which is used to
clear the silt accumulation in the reservoir side.
TGravity Dams:
PES OF DAMS
These dams are heavy
and massive wall-like
structures of concrete in
which the whole weight
acts vertically
downwards
Reservoir
Force
As the entire load is transmitted on the small area of
foundation, such dams are constructed where rocks are
competent and stable.
Bhakra Dam is the
highest Concrete
Gravity dam in Asia
and Second Highest
in the world.
Bhakra Dam is across
river Sutlej in
Himachal Pradesh
The construction of
this project was
started in the year
1948 and was
completed in 1963 .
• It is 740 ft. high above the deepest foundation as straight concrete dam
being more than three times the height of Qutab Minar.
• Length at top 518.16 m (1700 feet); Width at base 190.5 m (625 feet),
and at the top is 9.14 m (30 feet)
Buttress Dam ress
Dam:
Buttress Dam – Is a gravity
dam reinforced by
structural supports
Buttress - a support that
transmits a force from a
roof or wall to another
supporting structure
This type of structure can be considered even if the
foundation rocks are little weaker
These type of dams are
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 abutments
Arch dams are built across
narrow, deep river gorges, but
now in recent years they have
been considered even for little
wider valleys.
Arch dams ch
Dams:
TYPICAL NOF SECTION TYPICAL NOF SECTION
TYPICAL OVERFLOW SECTION
1. Solid Gravity dams :
This type of dam is the most rigid and requires
the least maintenance. It is adaptable to all
localities, but the height is governed by the
strength of the foundations. This type of dam
resists overturning moments of water pressure
by its weight alone.
2. Hollow Gravity Concrete Dam:
Hollow dams are constructed of reinforced
concrete
3. Buttress Dams:
These can be either Deck type with a RCC
Slab spanning between adjacent buttresses
or Multiple Arches supported on Butresses.
4. Arch Concrete Dams:
These Dams are curved in plan and resist the
water pressure partly by their weight and
partly by arch action, spanning to abutments,
and thus transferring a part of water thrust
to the abutments
Explanation: