Engineering Geology unit 5.pdf

ADITYA ENGINEERING COLLEGE (A)
Engineering Geology
Unit 5 : Geological Considerations in
selection of sites for dams, reservoirs and
successful tunnelling.
Unit – 1: Case studies and Unit – 5
geophysics
By
Sr. Asst. Prof. P Shiva Kumar
Civil Engineering Dept
Aditya Engineering College(A)
Surampalem.

Aditya Engineering College (A)
Engineering Geology
• In this session we shall focus on the following topics
1. Introduction and Definitions
2. History of dams world wide and in India
3. Classification of dams
4. Types of dams
5. Terminology of dams and reservoirs
6. Geology of reservoirs and streams ( hydrology of reservoirs)
7. Geological considerations for dams and reservoirs
8. Types of dam failures ( how are dams effected by hydraulic impound and weak
geological configuration effecting their design)
9. Addressing some case studies for dam failures in perspective of geology. ( unit 1 and 5
combined)
Tuesday, May 5, 2020
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Engineering Geology
Unit 5
• Introduction – Necessity of storing of water
With the emphasis on conservation of water and also the crisis of water
occurring for domestic, agricultural and industrial use there is a need to store
by controlling the flow of water into seas and oceans, also on different
landforms. The control of flow of surface water is possible by construction of
different types of dams based on location that suits to regulate the river flow
and divert the water into reservoirs for storing. All types of dams are man made
structures while reservoirs, some are natural and some of them were man
made (which dealt with huge loss of lands and low lying areas ).
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Engineering Geology Tuesday, May 5, 2020
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Dam is defined as a barrier built across a stream, river or estuary to confine and check the flow of water for such uses
as human consumption, irrigation, flood control and electric-power generation (Encyclopedia Britannica 1987). The
dams in the ancient times were built to control the floods, navigation, drinking and irrigation purposes only. But in
the modern times, these are constructed for wider use for development purposes such as to control soil erosion, for
generation of electricity, industrial use, aquaculture and tourism and so on.
Reservoir is an open-air storage area (usually formed by masonry or earthwork) where water is collected and kept in
quantity so that it may be drawn off for use (Encyclopedia Britannica 1987).
A reservoir (from French reservoir – a "tank") is, most commonly, an enlarged natural or artificial lake, pond or
impoundment created using a dam or lock to store water.
Reservoirs can be created in a number of ways, including controlling a watercourse that drains an existing body of
water, interrupting a watercourse to form an embayment within it, through excavation, or building any number
of retaining walls or levees.
Defined as a storage space for fluids, reservoirs may hold water or gasses, including hydrocarbons. Tank
reservoirs store these in ground-level, elevated, or buried tanks. Tank reservoirs for water are also called cisterns.
Most underground reservoirs are used to store liquids, principally either water or petroleum, below ground (
Wikipedia).

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cisterns

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Classifications of dams
Based on function
• Storage dams: As the name suggests, this dam is constructed to store the water during the rainy season when
there is a large flow of water. Storage dams store water for hydroelectric power generation, irrigation or flood
control project or may be used for improved habitat for fish and wildlife. A dam’s primary function is to store
water. Hence a dam is a storage dam unless qualifies otherwise
• Detention dams: A detention dam is a dam built to catch surface runoff and stream water flow to regulate the
water flow in areas below the dam
• Diversion dams : A dam built to divert water from a waterway or stream into a different watercourse.
• Debris dams: The dam constructed to retain the debris from the river is called a debris dam. This dam holds
off the debris like sand, gravel and drift wood flowing in the river with water. When the river passes the debris
dam, the water is relatively clear.
• Coffer dams : A coffer dam is a temporary dam constructed to ease construction. It’s an enclosure constructed
around the site to exclude the water so that the construction is done in dry condition

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Based on their structure and design
• Gravity dams: A gravity dam is an enormous sized dam composed from concrete and stone
masonry which are designed to retain large volumes of water.
• Earth dams: An earth dam (made up of soil) is built by compacting each layers of soil. The most
impervious material is used to form the core and placing the permeable material on the upstream
and downstream sides.
• Rock fill dams: This is a type of embankment dam which uses various sizes of materials to
provide stability. This dam uses rock fragments and boulders of large size.
• Arch dams: This dam is curved in plan with its convexity towards the upstream side.
• Buttress dams: This dam, also called as hollow dam, is a dam with a water tight upstream side
that is supported at intervals on the downstream side by a series of buttress or supports.
• Steel dams: A steel dam comprises of a steel frame work with steel skin plates on the upstream
side.
• Timber dams: This type of dam is made of wood, usually primarily coniferous timber such as pine
and fir. These are good for small heads and have sluices. The opening of the timber dams are
controlled by flanks and the sluices are very long, divided into several openings. These openings
are covered with wooden shields that can be raised and lowered.

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Arch Dam
A concrete or masonry dam, which is curved upstream so as to transmit the major part of the water load to the
abutments. Double curvature arch dam is a dam, which is curved vertically as well as horizontally.
Types of Dams
Types of arch dams
1. Double Curvature arch dam
2. Constant radius arch dam
3. Variable radius arch dam
4. Constant angle arch dam
For saving concrete and better
resistance

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Buttress
A dam consisting of a watertight part supported at intervals on the downstream side by a series of buttresses. A
buttress dam can take many forms, such as a flat slab or a massive head buttress. 1] Ambursen dam. A buttress
dam in which the upstream part is a relatively thin flat slab usually made of reinforced concrete. 1] Multiple arch dam.
A buttress dam composed of a series of arches for the upstream face.
Types of arch
dams
1. Rigid buttress
dams
2. Deck slab
buttress dams
3. Bulk head
buttress dams

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Coffer Dam
A temporary structure enclosing all or part of the construction area so that construction can proceed in the dry. A diversion
cofferdam diverts a stream into a pipe, channel, tunnel, or other watercourse.
1] Earthen cofferdam, 2] Rock fill cofferdam
3] Single-walled cofferdam, 4] Double-walled cofferdam
5] Braced cofferdam,
6] Cellular cofferdam (Circular or diaphragm type)

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Cellular cofferdam

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Diversion Dam
A dam built to divert water from a waterway or stream into a different watercourse.
All types of diversion dams are built by different designs existing from various dams themselves

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Embankment Dam
Any dam constructed of excavated natural materials or of industrial waste materials. 1] Earth dam . An embankment dam in which
more than 50 percent of the total volume is formed of compacted earth material generally smaller than 3-inch size. 2] Hydraulic fill
dam . An embankment dam constructed of materials, often dredged, which are conveyed and placed by suspension in flowing
water. 3 ] Rock fill dam. An embankment dam in which more than 50 percent of the total volume is composed of compacted or
dumped cobbles, boulders, rock fragments, or quarried rock generally larger than 3-inch size.

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Gravity Dam
A dam constructed of concrete and/or masonry, which relies on its weight and internal strength for stability. 2] Hollow
gravity dam. A dam constructed of concrete and/or masonry on the outside but having a hollow interior relying on its
weight for stability. 2] Crib dam. A gravity dam built up of boxes, crossed timbers, or gabions filled with earth or rock.
3] Roller-compacted concrete dam. A concrete gravity dam constructed by the use of a dry mix concrete transported
by conventional construction equipment and compacted by rolling, usually with vibratory rollers.

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Hydropower Dam
A dam that uses the difference in water level between the reservoir pool elevation and the tail water
elevation to turn a turbine to generate electricity.

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Industrial Waste Dam
An embankment dam, usually built in stages, to create storage for the disposal of waste products from an industrial
process. The waste products are conveyed as fine material suspended in water to the reservoir impounded by the
embankment. The embankment may be built of conventional materials but sometimes incorporates suitable waste
products. 1] Mine tailings dam. An industrial waste dam in which the waste materials come from mining operations
or mineral processing.

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Masonry Dam
Any dam constructed mainly of stone, brick, or concrete blocks jointed with mortar. A dam having only a
masonry facing should not be referred to as a masonry dam ( Rock fill dam) .1] Rubble dam . A stone
masonry dam in which the stones are unshaped or uncoursed (Varying shapes and sizes) .

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Overflow Dam
Overflow Dam. a dam designed for
raising the water level of rivers or for
creating a reservoir; it permits
the overflow of water during the
passage of excess (flash-flood)
discharges over the entire length of
the dam crest or through drain
openings.

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Regulating (After bay) Dam
A dam impounding a reservoir from which water is released to regulate the flow downstream.

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Saddle Dam (or Dike)
A subsidiary dam of any type constructed across a saddle or low point on the perimeter of a reservoir. This is
similar to a levee, which is a wall or embankment built along a river or stream to protect adjacent land from
flooding.

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A check dam is a small, sometimes temporary, dam constructed across a swale, drainage ditch, or waterway to
counteract erosion by reducing water flow velocity. Check dams themselves are not a type of new technology;
rather, they are an ancient technique dating from the second century A.D. Check dams are typically, though not
always, implemented in a system of several dams situated at regular intervals across the area of interest.
check dam

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A dry dam is a dam constructed for the
purpose of flood control. Dry dams typically
contain no gates or turbines, and are
intended to allow the channel to flow freely
during normal conditions. During periods of
intense rainfall that would otherwise cause
floods, the dam holds back the excess
water, releasing it downstream at a
controlled rate.
Dry dam

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Underground dam

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Natural dam
Dams can also be created by natural
geological forces. Lava dams are
formed when lava flows,
often basaltic, intercept the path of a
stream or lake outlet, resulting in the
creation of a natural impoundment.
An example would be the eruptions of
the Uinkaret volcanic field about 1.8
million–10,000 years ago, which
created lava dams on the Colorado
River in northern Arizona in
the United States.

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Beaver dam
Beaver dams or beaver impoundments are dams built by beavers to provide ponds as protection against predators such as
coyotes, wolves, and bears, and to provide easy access to food during winter. These structures modify the natural environment in
such a way that the overall ecosystem builds upon the change, making beavers a keystone species. Beavers work at night and
are prolific builders, carrying mud and stones with their fore-paws and timber between their teeth.

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A weir or low head dam is a barrier across the width of a river that alters the flow characteristics of water and
usually results in a change in the height of the river level. There are many designs of weir, but commonly water
flows freely over the top of the weir crest before cascading down to a lower level.
Low head dam or weir

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Barrage (Low head dam)
A barrage is a type of low-head, diversion dam which consists of a number of large gates that can be opened or
closed to control the amount of water passing through. This allows the structure to regulate and stabilize river
water elevation upstream for use in irrigation and other systems. The gates are set between flanking piers which
are responsible for supporting the water load of the pool created. The term barrage is borrowed from
the French word "barrer" meaning "to bar". Prakasham barrage constructed across
Krishna river which is of 1.23 km of
length and connecting Guntur and
Vijayawada districts and it is named
after the first chief minister of Andhra
Pradesh Tanguturi Prakasham Pantulu.
The barrage was constructed after the
endorsement made by Major Cotton to
East India Company and costed 1.75
crores in those days and irrigating 7
lakh acres of agricultural land.
The barrage was started in 1852 and
completed in 1855. Also later the
barrage was again constructed in 1957
with 1.2 million acre land for irrigation.

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Dams in India
List of Major Dams India
Name of Dam State River
Nizam Sagar Dam Telangana Manjira River
Somasila Dam Andhra Pradesh Pennar River
Srisailam Dam Andhra Pradesh Krishna River
Singur dam Telangana Manjira River
Ukai Dam Gujarat Tapti River
DharoiDam Gujarat SabarmatiRiver
Kadana dam Gujarat Mahi River
Dantiwada Dam Gujarat Banas River
Pandoh Dam HimachalPradesh Beas River
Bhakra NangalDam HimachalPradesh and Punjab Border Sutlej River
Nathpa JhakriDam HimachalPradesh Satluj River
ChameraDam HimachalPradesh Ravi River
Baglihar Dam Jammu and Kashmir Chenab River
Dumkhar HydroelectricDam Jammu and Kashmir IndusRiver
Uri Hydroelectric Dam Jammu and Kashmir Jhelum River
Maithon Dam Jharkhand Barakar River
Chandil Dam Jharkhand SwarnarekhaRiver
Panchet Dam Jharkhand DamodarRiver
Tunga Bhadra Dam Karnataka TungabhadraRiver
Linganamakkidam Karnataka SharavathiRiver
Kadra Dam Karnataka Kalinadi River
AlamattiDam Karnataka Krishna River
Supa Dam Karnataka Kalinadi or Kali river
Krishna Raja SagaraDam Karnataka KaveriRiver
HarangiDam Karnataka HarangiRiver
NarayanpurDam Karnataka Krishna River
KodasalliDam Karnataka Kali River
MalampuzhaDam Kerala MalampuzhaRiver
Peechi Dam Kerala Manali River
Idukki Dam Kerala Periyar River
Kundala Dam Kerala Kundala Lake
Parambikulam Dam Kerala Parambikulam River
WalayarDam Kerala WalayarRiver
Mullaperiyar Dam Kerala Periyar River
Neyyar Dam Kerala Neyyar River
RajghatDam Uttar Pradesh and Madhya Pradesh Border Betwa River
Barna Dam Madhya Pradesh Barna River
BargiDam Madhya Pradesh NarmadaRiver
BansagarDam Madhya Pradesh Sone River
GandhiSagar Dam Madhya Pradesh ChambalRiver
Yeldari Dam Maharashtra Purna river
Ujani Dam Maharashtra Bhima River
Pawna Dam Maharashtra MavalRiver
Mulshi Dam Maharashtra Mula River
Koyna Dam Maharashtra Koyna River
JayakwadiDam Maharashtra GodavariRiver
Bhatsa Dam Maharashtra Bhatsa river
Wilson Dam Maharashtra PravaraRiver
Tansa Dam Maharashtra Tansa river
PanshetDam Maharashtra Ambi River
Mula Dam Maharashtra Mula river
Kolkewadi Dam Maharashtra Vashishti River
Girna Dam Maharashtra Girana river
Vaitarna Dam Maharashtra Vaitarna river
RadhanagariDam Telangana BhogawatiRiver
Lower Manair Dam Telangana Manair River
Mid Manair Dam Telangana Manair River and SRSP Flood Flow Canal
Upper Manair Dam Telangana Manair River and Kudlair River
KhadakwaslaDam Maharashtra Mutha River
Gangapur Dam Maharashtra Godavaririver
JalaputDam Andhra Pradesh and Odisha Border Machkund River
IndravatiDam Odisha IndravatiRiver
Hirakud Dam Odisha MahanadiRiver
Vaigai Dam Tamil Nadu Vaigai River
PerunchaniDam Tamil Nadu ParalayarRiver
Mettur Dam Tamil Nadu KaveriRiver
Govind Ballabh PantSagar Dam also Rihand dam Uttar Pradesh Rihand River
Tehri Dam Uttarakhand BhagirathiRiver
Dhauli Ganga Dam Uttarakhand Dhauli Ganga River
These are list of 69 major dams constructed
in India.
Although there were nearly 3200 major /
medium dams and barrages had been
constructed in India by the year 2012.
https://en.wikipedia.org/wiki/List_of_dams
_and_reservoirs_in_India
You can do a small survey or comparative
study of major minor, smaller or larger, type
of material, power generation capacity and
total volume of water, total land being
irrigated etc. from the above link if you are
an enthusiastic.

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Try to write an assignment for this revision class
Collecting the information of dams constructed through out the world and in India.
Make a comparative study by classifying them in to the following:
1] largest and smallest dams world wide and in India
2] classify all the dams based on the a] material, b] design, c] function, d] generation hydro electricity, e] acres of
land being irrigated world wide and in India.
3] oldest and newest dams world wide and in India
4] oldest working dams world wide and in India.
5] comparison of dams constructed in India with other dams world wide in different parameters like cost, time,
amount of concrete, earth materials, power generation, amount of water holding capacity, amount of land being
irrigated, no of aqueducts and canals constructed.
First try to figure out all the above in India, later you can go for world wide.

Engineering Geology
ABUTMENT: The part of the valley side against which the dam is constructed. May also refer to an artificial abutment sometimes constructed as a
concrete wall. Right and left abutments are those on respective sides as an observer when viewed looking downstream.
BASE WIDTH: The width of the dam measured along the dam/foundation interface.
BREACH: An opening or a breakthrough of a dam sometimes caused by rapid erosion of a section of earth embankment by water.
CONDUIT: A closed channel to convey the discharge through or under a dam. Usually pipes constructed of concrete or steel.
CORE (IMPERVIOUS CORE)
(IMPERVIOUS ZONE):
A zone of material of low permeability in an embankment dam, hence the terms central core, inclined core, puddle clay core, and
rolled clay core.
CREST LENGTH: The developed length of the top of the dam. This includes the length of the spillway, powerhouse, navigation lock, fish pass, etc.,
where these structures form part of the length of the dam. If detached from the dam, these structures should not be included.
CREST OF DAM: The term crest of dam is often used when top of spillway and top of dam should be used for referring to the overflow section and dam
proper, respectively.
CUTOFF: An impervious construction by means of which seepage is reduced or prevented from passing through foundation material.
CUTOFF WALL: A wall of impervious material, e.g., concrete, wood pilings, steel sheet piling, built into the foundation to reduce seepage under the
dam.
DRAINAGE LAYER OR
BLANKET:
A layer of pervious material placed directly over the foundation material or downstream slope to facilitate seepage drainage of the
embankment. May also use an upstream blanket placed on the impoundment floor and upstream embankment to prevent seepage
entering the dam.
DRAWDOWN: The resultant lowering of water surface level due to release of water from the reservoir.
EMBANKMENT: Fill material, usually earth or rock, placed with sloping sides.
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Terminology of DAMS

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EMERGENCY ACTION PLAN: A predetermined plan of action to be taken to reduce the potential for property damage and loss of lives in an area affected
by a dam break.
FACE: With reference to a structure, the external surface that limits the structure, e.g., the face of the wall or dam.
FLASHBOARDS: Lengths of timber, concrete, or steel placed on the crest of a spillway to raise the operating water level but that may be
quickly removed in the event of a flood either by tripping a supporting device or by designing the flashboard supports to fail
under specified conditions.
FOUNDATION OF DAM: The natural material on which the dam structure is placed.
FREEBOARD: The vertical distance from the water surface to the lowest elevation at which water would flow over the dam at a section
not designed to be overflowed.
GATE: In general, a device in which a leaf or member is moved across the waterway from an external position to control or stop
the flow.
CREST GATE (SPILLWAY GATE): A gate on the crest of a spillway that controls overflow or reservoir water level.
FLAP GATE: A gate hinged along one edge, usually either the top or bottom edge. Examples of bottom-hinged flap gates are tilting gates
and fish belly gates so called from their shape in cross section.
OUTLET GATE: A gate controlling the outflow of water from a reservoir.
RADIAL GATE (TAINTER GATE): A gate with a curved upstream plate and radial arms hinged to piers or other supporting structures.
SLIDE GATE (SLUICE GATE): A gate that can be opened or closed by sliding in supporting guides.
HEEL OF DAM: The junction of the upstream face of a gravity or arch dam with the foundation surface. In the case of an embankment dam
the junction is referred to as the upstream toe of the dam.

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INTAKE: Any structure in a reservoir, dam, or river through which water can be drawn into an outlet pipe, flume, etc.
LOW LEVEL OUTLET
(BOTTOM OUTLET):
An opening at a low level from the reservoir generally used for emptying the impoundment.
OUTLET: An opening through which water can be freely discharged for a particular purpose from a reservoir.
PERVIOUS ZONE: A part of the cross section of an embankment dam comprising material of high permeability.
RIPRAP: A layer of large uncoursed stones, broken rock, or precast blocks placed in random fashion on the upstream slope of an
embankment dam, on a reservoir shore, or on the sides of a channel as a protection against wave and ice action.
SEEPAGE COLLAR: A projecting collar usually of concrete or steel built around the outside of a pipe, tunnel, or conduit, under an embankment dam,
to lengthen the seepage path along the outer surface of the conduit.
SPILLWAY: A structure over or through which flood flows are discharged. If the flow is controlled by gates, it is considered a controlled
spillway; if the elevation of the spillway crest is the only control, it is considered an uncontrolled spillway.
AUXILIARY SPILLWAY
(EMERGENCY SPILLWAY):
A secondary spillway designed to operate only during exceptionally large floods.
OGEE SPILLWAY (OGEE
SECTION):
An overflow spillway, which in cross section the crest, downstream slope, and bucket have an “S” or ogee form of curve. The shape
is intended to match the underside of the nappe at its upper extremities.
SPILLWAY CHANNEL
(SPILLWAY TUNNEL):
A channel or tunnel conveying water from the spillway to the river downstream.
STOPLOGS: Large logs, timbers or steel beams placed on top of each other with their ends held in guides on each side of a channel or conduit
so as to provide a cheaper or more easily handled means of temporary closure than a bulkhead gate.
STRUCTURAL HEIGHT: The vertical distance from the lowest point of natural ground on the downstream side of the dam to the highest part of the dam
which would impound water.

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TOE OF DAM: The junction of the downstream face of a dam with the natural ground surface. This is also referred to as the downstream toe. For
an embankment dam the junction of the upstream face with ground surface is called the upstream toe.
TOP OF DAM: The elevation of the upper most surface of a dam, usually a road or walkway, excluding any parapet wall, railings, etc.
TOP THICKNESS (TOP
WIDTH):
The thickness or width of a dam at the top of the dam. In general, the term thickness is used for gravity and arch dams, width is
used for other dams.
TRAINING WALL: A wall built to confine or guide the flow of water.
TRASH RACK: A screen comprising metal or reinforced concrete bars located in the waterway at an intake so as to prevent the ingress of floating
or submerged debris.
TAIL WATER: Tailwater refers to waters located immediately downstream from a hydraulic structure, such as a dam (excluding minimum release
such as for fish water), spillway, bridge or culvert.
GALLERIES: The normal function of a gallery is to provide access for inspection purposes, to monitor the behaviour of the dam, and to carry out
remedial work if required. It must therefore be of sufficient height to permit easy movement of personnel and minor equipment,
commonly 2.13m but varied to suit construction methods.
SLUICE GATE :-
Sluice gates are
provided for controlled
supply of water from any
water source like Dam,
canal, river etc.

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Flash boards Stop logs

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Berm is a man-made
sediment barrier
placed at the edge of
a slope or a wall built
adjacent to a ditch to
guard against
potential
flooding. Berms are
placed in flood-prone
areas to protect
against erosion, run-
off and high water.

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The Geological Considerations in selection of dam sites must satisfy the following requirements, they are
a) Narrow river valley
b) Occurrence of the bedrock at a shallow depth
c) Competent rocks to offer a stable foundation
d) Sound geological structures
Banasura Sagar Dam,
Wayyinad, Kerala
Hoover
dam,
Boulder
city,
Nevada,
USA

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b) Occurrence of the bedrock at a shallow depth

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Charnockite

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Khondalite Granite Gneiss
Red
Sandsone

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The Cretaceous-
Tertiary extincti
on event, or
the K-T event, is
the name given
to the die-off of
the dinosaurs
and other
species that took
place some 65.5
million years
ago.
This suggests that
a comet, asteroid
or meteor impact
event may have
caused
the extinction of
the dinosaurs

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c) Competent rocks to offer a stable foundation
• The Thickness of sediments or loose overburden along the river valley depends on the nature and the stage of
development of the river. In other words, strong and fresh bedrocks may occur at or near the surface, therefore only small
dams may be suitable thee to serve a limited purpose.
• The general occurrence of material like clay, silt, sand and gravel along the river bed, naturally makes it difficult to
assess the thickness of loose overburden by mere surficial studies. Therefore to know the bedrock profile, geophysical
investigations such as “Electrical Resistivity studies” or “Seismic refraction Studies” are carried out carefully. The
data recorded in the field during investigations are interpreted and the required bedrock profile is visualized.

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• If Igneous rock occurs at the selected dam site, they will offer a safe basis, and weak sedimentary rocks,
particularly shale's, poorly cemented sandstones and limestone's shall naturally be undesirable to serve as
foundation rocks.
The suitability or otherwise of a site to serve as a foundation for major dams depends on factors such as :
• The existing rock type at the dam site.
• The extent of weathering it has undergone
• The occurrence of intrusions
• The extent of fracturing
• The extent of geological structures, the mode and number of rock types concerned.
Suitability of Igneous Rocks
• Among the rock types, the occurrence of massive plutonic and (or) hyperbyssal igneous rocks is the most
desirable at the dam site because they are very strong and durable due to their dense character. Interlocking
texture, hard silicate mineral composition, occurrence of negligible porosity and permeability, absence of any
inherent weak planes, resistance of weathering and their tendency to occur over wide areas. Thus all plutonic rocks
like Granites, Syenites, diorites and gabbros are very competent and desirable rocks.
• However, volcanic rocks which are vesicular or amygdaloidal, are not equally desirable, obviously because these
character contributes to porosity, permeability and hollowness which, in turn, reflect the strength of the rocks.
• Of Course, it is necessary that such rocks should not have been affected by any intense weathering or fracture or dykes or
adverse geological structures like shearing, faulting and jointing.
A) Suitability of Igneous Rocks

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B) Suitability of Sedimentary Rocks
• In this case of sedimentary rocks, the bedding and its orientation, thickness of beds, nature and extent of compaction
and cementation, grain size, leaching of soluble matter, porosity and permeability, associated geological structures and
composition of constituents (i.e. Sediments, cementing material, etc.) influence the strength and durability of different
sedimentation rocks.
Conglomerate
laterite Limestone and sand stone
Shale

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C) Suitability of Metamorphic Rocks
• Among the metamorphic rocks:
• “Gneisses” are generally competent like granites, unless they possess a very high degree of foliations and
are richly accompanied by mica-like minerals.
• Quartzite's are very hard and highly resistant to weathering. They are neither porous nor permeable.
• Marbles, like quartzite, are compact, bear a granulose structure, are not porous, nor permeable and
reasonably
strong too. But by virtue of their chemical composition and minerals they are unsuitable at dam sites.
• Slates bear a typical slaty cleavage. Hence this rock is soft and weak and undesirable at dam sites.
Gneiss Schist Quartzite Marble

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4) Influencing of Weathering and Erosion

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Reservoirs
Reservoir is a man made structure to store the water, whether it may be a storm water or
river water. Since it is artificial on that cant be termed or often confused large lakes.
But large lakes if possible can be converted in to reservoirs.
There are three types of reservoirs
A) Valley dammed reservoirs
B) Service reservoirs
C) Bank side reservoirs
Remaining are from above with different names based on specific purpose
A) Other reservoirs also include based on their purpose – storage/ conservational reservoirs
B) Flood control reservoirs ( Similar to bank side reservoirs)
C) Multipurpose reservoirs (Water supply, recreational, environmental etc.)
D) Distribution reservoirs ( Water supply system)
E) Pumped storage reservoirs

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MARTON RESERVOIR , Marton,Town in the North
Island, New Zealand
Concrete
Structures (NZ)
Te Aroha,
Marton,Town in
the North Island,
New Zealand

P Shiva Kumar
Pumped-storage reservoirs

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Retardation or fluctuation produced
in reservoir

P Shiva Kumar
The Los Angeles
Department of
Water and
Power released
96 million black
shade balls into
the Los Angeles
Reservoir to
reduce
evaporation and
deter algal
growth.

Engineering Geology
• The 5 Big Tunnels in India
• Atal Tunnel (previously known as Rohtang Tunnel), named after India's former Prime Minister Atal Bihari Vajpayee, is a highway tunnel
being built under the Rohtang Pass in the eastern Pir Panjal range of the Himalayas on the Leh-Manali Highway. At 8.8 km (5.5 mi) length,
the tunnel will be one of the longest road tunnels in India and is expected to reduce the distance between Manali and Keylong by about
46 km (28.6 mi).The tunnel is at an elevation of 3,100 meters (10,171 ft) whereas the Rohtang Pass is at an elevation of 3,978 meters
(13,051 ft.). The excavation of the tunnel completed in October 2017 when the blasting from south and north ends joined, and the
completed tunnel will open in June 2020.
• Challenges
The most challenging task was to continue the excavation during heavy snowfall in winter. Excavation for tunneling was done from
both ends. However, as Rohtang pass closes during the winter, the north portal was not accessible during winter and the excavation
was being done only from the south portal in winters. Only about one-fourth of the entire tunnel was excavated from the north end
and three-fourths was excavated from the south end. There were more than 46 avalanche sites on approaches to the tunnel. Other
challenges to the progress of the tunnel included difficulties in disposing more than 800,000 m³ of excavated rock and soil, heavy
ingress of water (as much as 3 million liters per day in June 2012)[ that required constant dewatering, costlier treatment and slowed
the progress of excavation from 5 meter per day to just half a meter a day and unstable rocks that slowed blasting and digging. A
cloud-burst and flash flood on 8 August 2003 killed 42 laborers who were building the temporary access road. Questions were also
raised on the impact of cutting down more than 700 trees on the ecology.
• https://en.wikipedia.org/wiki/Atal_Tunnel
• https://sciencing.com/types-rocks-found-himalayas-8523001.html
• https://en.wikipedia.org/wiki/List_of_rail_tunnels_in_India_by_length
• http://www.walkthroughindia.com/walkthroughs/the-5-big-tunnels-in-india/
P Shiva Kumar

Engineering Geology
• Jawahar Tunnel
• Jawahar Tunnel also called Banihal Tunnel or Banihal Pass is a road tunnel in Indian union territory of Jammu and Kashmir. Named after
the first Prime Minister of India Jawaharlal Nehru, it was constructed for round-the-year surface transport between 1954 and 1956. The
Jawahar tunnel has been operational since 22 December 1956. The length of tunnel is 2.85 km (1.77 mi). It has one lane road in either
direction. It is situated between Banihāl and Qazigund on NH 1A that has been renumbered NH 44.[2] The tunnel facilitates round-the-year
road connectivity between Srinagar and Jammu.
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https://en.wikipedia.org/wiki/Jawahar_Tunnel

Engineering Geology
• The Maliguda Tunnel of Odisha is the 4th Biggest broad-gauge railway tunnel in India after "Banihal - Quazigund
Tunnel" which is in the state of Jammu & Kashmir. The tunnel is 13 km east of Jeypore, India, 27 km from Koraput.The
tunnel on which the entire route of 430 km was built by Japan Engineers in between (1961-66)
with Japanese collaboration for the supply of Iron Ore from Kirandul to Vizag Port via- Dantewara, Jagdalpur, Jeypore,
Koraput, Padua, Araku, Kottavalasa.
P Shiva Kumar

Engineering Geology
• Karbude Tunnel is the longest rail tunnel in India located on the Konkan Railway route near Ratnagiri in
Maharashtra. The Karbude tunnel is 6.5 km long and one of the India’s biggest engineering marvels. Ratnagiri region is
full of lush greenery and more, it is well famous for for different varieties of Mangoes. Konkan Railway runs from
Mangalore in Karnataka to Mumbai in Maharashtra through Goa, along the west coast of India and Western Ghats.
P Shiva Kumar
The Western Ghats are the mountainous faulted and eroded edge of
the Deccan Plateau. Geologic evidence indicates that they were formed
during the break-up of the supercontinent of Gondwana some 150
million years ago. Geophysical evidence indicates that the west coast of
India came into being somewhere around 100 to 80 mya after it broke
away from Madagascar. After the break-up, the western coast of India
would have appeared as an abrupt cliff some 1,000 m (3,300 ft)
in elevation.[15] Basalt is the predominant rock found in the hills
reaching a thickness of 3 km (2 mi). Other rock types found
are charnockites, granite gneiss, khondalites, leptynites,
metamorphic gneisses with detached occurrences of
crystalline limestone, iron ore, dolerites and anorthosites.
Residual laterite and bauxite ores are also found in the southern hills

Engineering Geology
• Bhatan Tunnel on Mumbai-Pune Expressway is 1KM long road tunnel with all the possible new technology. The
Mumbai-Pune Expressway is the first six-lane concrete, high-speed, access controlled tolled expressway. The expressway
has reduced the travel time between the cities of Mumbai and Pune to approximately two hours. There are total 5 tunnel
in Mumbai-Pune Expressway, Bhatan tunnel is one of the longest tunnel.
P Shiva Kumar
There are so many other road and railway tunnels in
India,such as Khowai in Tripura and Sangar tunnel and
latest India’s longest railway tunnel named as Pir Panjal
tunnel in Jammu and Kashmir. Other newly constructed
Katraj tunnel Pune and Punarjani Guha, a natural tunnel
150 meters long in the rocky cliff in Kerala.
https://www.geodata.it/images/geodata/giordano-
russo/india.pdf

P Shiva Kumar
https://www.intechopen.com/books/tunnel-engineering-selected-topics/engineering-geology-and-tunnels

Engineering Geology unit 5.pdf

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