This document provides an overview of the analysis and design of a gravity dam located in seismic zone V. It discusses the project team members and then covers the basic structure and purpose of dams. It reviews the history of dam construction and provides examples of different dam types. The document outlines the necessary investigations and considerations for dam design, including stability, sedimentation, spillways, and energy dissipation structures.

1. Analysis and design of gravity
dam in seismic zone V
Project by:
• Mr. Risso Johnny
• Mr. Kapu Takar
• Mr. Atan Ketan
• Mr. Manoj Thorat
• Mr. Shaikh Arshanaj.

2. Dam
• Dam is a solid barrier constructed at a suitable
location across a river valley to store flowing water.
Need and Necessity:
• Irrigation
• Water for domestic consumption
• Drought and flood control
• For navigational facilities
• Hydroelectric power generation
• Recreation
• Development of fish & wild life
• Soil conservation
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3. History of Dams
• First dam was constructed by the Egyptians in
2950-2750 B.C, using stone/ brick masonry.
• Earth dam was built first in Mesopotamia
around 2000 B.C.
• Romans used concrete and mortars around 100
AD.
• Due to large size and amount of building
material need to construct earth and gravity
dams
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4. Grand Anicut (Kallanai)
The oldest dam in the world
Built by Chola king Karikalan
around the 2nd Century AD
 to divert the waters of the
Kaveri across the fertile delta
region for irrigation via canals.
 It is constructed from unhewn
stone spanning the Kaveri and
is 329 m (1,079 ft.) long, 20 m
(66 ft.) wide and 5.4 m (18 ft.)
high
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5. Structure of Dam
Crest Spillway
(inside dam)
MWL
Max. level
NWL
Normal
water level
Upstream Down stream
Free board
Sluice way
Gallery
Heel Toe

6.  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.
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7. TYPES OF
DAMS:
Gravity Dams:
Reservoir
• These dams are heavy
Force and massive wall-like
structures of concrete
in which the whole
weight acts vertically
downwards
As the entire load is transmitted on the small area of foundation,
such dams are constructed where rocks are competent and stable
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8. Buttress
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
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9. Arch Dams:
• 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.
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10. 10

11. Earth Dams:
• 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
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12. Dam Building Project
• Planning
- Reconnaissance Study
- Feasibility Study
- Environmental Document
• Design
- Preliminary (Conceptual) Design
- Detailed Design
- Construction Documents (plans &
specifications)
• Construction
• Startup and testing
• Operation
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13. Necessary Data
• Location and site map
• Hydrologic data
• Climatic data
• Geological data
• Water demand data
• Dam site data (foundation,
material, tailwater)
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14. SELECTION OF SITES
PLACE MUST BE SUITABLE
NARROW GORGE OR SMALL VALLEY
WITH ENOUGH CATCHMENT AREA
WHY DO WE
TO STORE A
NEED A
CALCULATED
LARGE
VOLUME OF
CATCHMENT
WATER
AREA?
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15. Large storage capacity
Length of dam to constructed is less.
Water-tightness of reservoir.
Good hydrological conditions
Deep reservoir
Small submerged area
Low silt inflow
No objectionable minerals
Low cost of real estate
Site easily accessible
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16. INVESTTIGATIONS
 Engineering surveys
 Geological investigations
 Hydrological investigations
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17. Engineering surveys
 Conducted for dam, reservoir and other
associated work.
 Topographic survey of the area is carried out
and the contour plan is prepared
 The horizontal control is usually provided by
triangulation survey, and the vertical control
by precise levelling
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18. Geological investigation
 Geological investigations of the dam and
reservoir site are done for the following
purposes.
(i) Suitability of foundation for the dam.
(ii) Water-tightness of the reservoir basin
(iii) Location of the quarry sites for the
construction materials.
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19. Hydrological investigations
 The hydrological investigations are conducted
for the following purposes :
(i) To study the runoff pattern and storage
capacity.
(ii) To determine the maximum discharge at
the site.
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20. Requirements for Stability
• Modes of failure of a gravity dam:
Overturning
Sliding
Compression or Crushing
Tension.
The design shall satisfy the following requirements of
stability:
 The dam shall be safe against sliding on any plane or
combination of planes within the dam, at the foundation or
within the foundation;
 The dam shall be safe against overturning at any plane
within the dam, at the base, or at any plane below the base;
and
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 The safe unit stresses in the concrete or masonry of the

21. Reservoir Sedimentation
 It is a difficult problem for which an economical
solution has not yet been discovered, except by
providing a “dead storage” to accommodate the
deposits during the life of the dam.
 Disintegration, erosion, transportation, and
sedimentation, are the different stages leading to
silting of reservoir.
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22. Causes of sedimentation
 Nature of soil in
catchment area
 Topography of the
catchment area
 Cultivation in
catchment area
 Vegetation cover in
catchment area
 Intensity of rainfall in
catchment area
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23. Sediment Management
• water with Maximum
efforts should be
released so that less Wooden barriers
sediments should retain
in reservoir.
Following options are:
– Catchment Vegetation
– Construction of coffer
dams/low height Sediment sluicing
barriers
– Flushing and desilting
of sediments
– Low level outlets /
sediment sluicing
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24. Spillways
Used to pass excess flow in a controlled fashion
• Two main types:
Control section
– Unregulated
– Regulated
Terminal structure Discharge channel
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25. SPILLWAYS
Types of Spillways
a. Overflow spillways
b. Chute spillways
c. Side-channel spillways
d. Shaft spillways
e. Siphon spillways
f. Service & Emergency spillways
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26. Overflow spillway side-channel spillway
Chute spillway Morning glory spillway
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27. Energy Dissipiators
• Hydraulic Jump type – induce a hydraulic
jump at the end of spillway to dissipate energy
• Bureau of Reclamation did extensive
experimental studies to determine structure
size and arrangements – empirical charts and
data as design basis
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28. Stilling basin Hydraulic jump
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29. THANK YOU!!!
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