baglihar hydro electric power plant
TRANSCRIPT
A MAJOR PROJECT REPORT
ON
CONSTRUCTION OF
HYDRO ELECTRIC POWER PLANT
Submitted in partial fulfillment of the requirement for Degree of
Bachelor of Engineering
In
CIVIL Discipline
Submitted To
[RAJIV GANDHI PRODYOGIKI VISHWAVIDYALAYA, BHOPAL (M.P.)]
Submitted By:
RAHUL SINGH (0171EC101069)
RAJA HAFIZANA AFROZ (0171CE101080)
STANZIN SPALZANG (0171CE101099)
Under The Guidance Of:
Prof. VIKRAM PARIHAR
(HOD, Department of Civil Engineering)
DEPARTMENT OF CIVIL ENGINEERING
ACROPOLIS INSTITUTE OF TECHNOLOGY& RESEARCH,
BHOPAL
SESSION: 2013-20114
Acropolis Institute of Technology & Research,
Bhopal (M.P.) Department of Civil Engineering
CERTIFICATE
This is to certify that the work embodies in this Project Report entitled
“CONSTRUCTION OF HYDRO ELECTRIC POWER PLANT” being submitted
by “Rahul Singh ” (0171EC101069),Raja Hafizana Afroz (0171CE101080),
Stanzin Spalzang (0171CE101099)for partial fulfillment of the requirement
for the degree of “Bachelor of Engineering in Civil Engineering”
discipline to “Rajiv Gandhi Praudyogiki Vishwavidyalaya, Bhopal(M.P.)”
during the academic year 2014-15 is a record of bonafide piece of work,
carried out by him under my guidance and guidance in the “Department
of Civil Engineering”, Acropolis Institute of Technology& Research,
Bhopal (M.P.).
APPROVED & GUIDED BY:
Prof. VIKRAM PARIHAR
(HOD, Department of Civil Engineering)
FORWARDED BY:
(Prof. VIKRAM PARIHAR) (Dr. Kunal Basu)
Head of Civil Engineering Director
AITR, Bhopal AITR, Bhopal
Acropolis Institute of Technology &Research
Bhopal (M.P.)
Department of Civil Engineering
Acropolis Institute of Technology & Research,
Bhopal (M.P.)
Department of Civil Engineering
DECLARATION
We, Rahul Singh (0171EC101069), Raja Hafizana Afroz
(0171CE101080), Stanzin Spalzang (0171CE101099)” students of
Bachelor of Engineering in Civil discipline, session: 2013-2014,
Acropolis Institute of Technology& Research, Bhopal (M.P.), hereby
declare that the work presented in this Project Report entitled
“CONSTRUCTION OF HYDRO ELECTRIC POWER PLANT” is
the outcome of my own work, is bonafide and correct to the best of my
knowledge and this work has been carried out taking care of Engineering
Ethics. The work presented does not infringe any patented work and has
not been submitted to any other university or anywhere else for the award
of any degree or any professional diploma.
Date: Rahul Singh(0171EC101069)
Raja Hafizana Afroz (0171CE101080)
Stanzin Spalzang (0171CE101099)
4
ACKNOWLEDGEMENT
I take the opportunity to express our sincere gratitude and deep sense of
indebtedness to our guide “Prof. Vikram Parihar” for the valuable guidance and
inspiration throughout the project duration. We feel thankful to him for his
innovative ideas, which led to successful completion of this project work. We feel
fortunate to work under such an outstanding mentor in the field of
“CONSTRUCTION OF HYDRO ELECTRIC POWER PLANT”. He has always
welcomed our problem and helped us to clear our doubt. We will always be
grateful to him for providing us moral support and sufficient time.
I owe sincere thanks to our GM Lt. Col.(Retd.) Lakhmeer Singh and all other
staff of JAYPEE ASSOCIATES LIMTED who helped us duly in time during our project work
in the Department.
At the same time, we would like to thank Prof. Vikram Parihar (HOD, CE) Sir
and all other faculty members and all non-teaching staff in Civil Department for
their valuable co-operation.
Rahul Singh (0171EC101069)
Raja Hafizana Afroz (0171CE101080)
Stanzin Spalzang (0171CE101099)”
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LIST OF PLANS AND SECTIONS
Layout of Stage-II Power House Complex.
L-Section of Baglihar Hydro Electric Project Stage-II.
Layout Plan & Sectional Details of Headrace Tunnel(HRT-II)
Layout Plan & Sections of Power House Cavity.
Layout Plan & Sections of Underground Cable Tunnel.
Layout Plan &Sections of Transformer Hall Cavity
Layout Plan &Sections of Tail Race Tunnel (TRT-II).
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TABLE OF CONTENTS
Certificate …………………………………………………………………................i
Declaration ………………………………………………………………….............ii
Acknowledgement …………………………………………………………………...iii
List of Plan……. ……………………………………………………………………iv
CHAPTER PAGE NO
CHAPTER 1
Dam………………………………………………………………….. 1
CHAPTER 2
Introduction about Hydro electricity…………………………….…… 2
Introduction about BHEP…………………………………………..… 3
CHAPTER 3
Specifications………………………………………………………… 4
CHAPTER 4
7
Equipments used………………………………………………………. 8
CHAPTER 5
HRT……………………………………………………………………. 19
CHAPTER PAGE NO
CHAPTER 6
TRT…………………………………………………………………. 23
CHAPTER 7
Surveying………………………………………………………………. 25
CHAPTER 8
Quality control………….……………………………………………….. 30
CHAPTER 9
Grouting and Rock Bolting……………………………………………….. 46
CHAPTER 10
Adit and Tunnel Construcion Methods……………………………………. 52
CHAPTER 11
Conclusion…………………………………………………………………. 55
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CHAPTER 1
DAM
The type of dam is Solid gravity concrete dam 143.0 m high from deep foundation level. It
consists of 5spillway bays having radial gates (10.0 m x10.5 m) with hydraulic hoists, 3chute
spillways of 12m width each and one auxiliary spillway of 6m Height having radial gates with
hydraulic hoists. There are 7 non over flow blocks on the left bank and 6 non-overflow blocks on
the right bank. The total length of the dam at top is 362.862m. The roadway on top of dam is at
EL 843m allowing a free board of 3m. The deepest foundation level for dam is at EL 700m. Thus
the height of dam is 143m above the deepest foundation level.
Based on the pond levels the inlets of intake has been kept at EL 821m and the spillway crest
level has been kept at EL 808m. The energy dissipation arrangement consists of splitters and
ledge on spillway surface. A 70m long plunge pool is provided below the spillway.
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CHAPTER 2
INTRODUCTION ABOUT HYDRO ELECTRICITY
Hydropower functions by converting the energy in flowing water into electricity. The volume of
water flow and the height (called the head) from the turbines in the power plant to the water
surface created by the dam determines the quantity of electricity generated. Simply, the greater
the flow and the taller the head means the more electricity produced.
The simple working of a hydropower plant has water flowing through a dam, which turns a
turbine, which then turns a generator. A hydropower plant (including a powerhouse) generally
includes the following steps:
1. The dam holds water back and stores water upstream in a reservoir, or large artificial
lake. The reservoir is often used for multiple purposes, such as the recreational Lake
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Roosevelt at the Grand Coulee Dam. Some hydroelectric dams do not impound water, but
instead use the power of the flowing river, and are known as run-of-the-river.
2. Gates open on the dam, allowing gravity to pull the water down through the penstock. An
intake conduit carries water from the reservoir to turbines inside the powerhouse.
Pressure builds up as water flows through the pipeline.
3. The water then hits the large blades of the turbine , making them turn. The vertical blades
are attached through a shaft to a generator located above. Each turbine can weigh as
much as 172 tons and turn at a rate of 90 revolutions per minute.
4. The turbine blades turn in unison with a series of magnets inside the generator. The large
magnets rotate past copper coils, which produce alternating current (AC).
5. The transformer inside the powerhouse takes the AC and converts it to higher-voltage
current so as to allow electricity to flow to customers.
6. Out of every power plant exit four power lines consisting of three wires (associated with
three power phases) and a neutral (ground) wire.
7. Used water is carried through outflow pipelines, which reenters the river downstream.
INTRODUCTION ABOUT BHEP
Baglihar Dam (Hindi: बगलिहार बााँध Baglihār Bāndh), also known as Baglihar Hydroelectric
Power Project, is a run-of-the-river power project on the Chenab River in the Ramban district of
the Indian state of Jammu and Kashmir. This project was conceived in 1992, approved in 1996
and construction began in 1999. The project is estimated to cost USD $1 billion. The first phase
of the Baglihar Dam was completed in 2004. With the second phase completed on 10 October
2008, Prime Minister Manmohan Singh of India dedicated the 900-MW Baglihar hydroelectric
power project to the nation.
The 900 MW capacity Baglihar Hydroelectric Project (J&K) is located on Jammu-Srinagar
highway, about 141 km from Jammu and is proposed to be constructed in two stages. BHEP
Stage-I (450 MW) is under construction and comprises a 144.5 m high concrete gravity dam on
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river Chenab, Power Intake Structure (2 x 430 cumec capacity for both stages), about 2.08 km
longHead Race Tunnel (HRT, 10.15 m dia circular), a 27.5 m dia and 77.0 m high restricted
orifice type upstream surge tank, three pressure shafts, an Underground Powerhouse cavity (3 x
150 MW installed capacity), Transformer hall cavity, Downstream Collection Gallery, about 160
m long Tail Race Tunnel (TRT, 10 m wide) and cable tunnel system (including pothead yard) for
both stages. In underground powerhouse complex there are three parallel large caverns i.e. 121 m
(L) x 24 m (W) x 50 m (H) size Powerhouse cavity, 112.25 m (L) x 15.0 m (W) x 24.5 m (H)
Transformer Hall cavity and 75 m (L) x 12.5 m (W) x 44.0 m (H) cavity for Collection Gallery.
The Main Access Tunnel (MAT) to the erection bay of BHEP Stage-I is 7.5m D-Shaped and
355.0 m long. Cavities for BHEP Stage-II are the extension of BHEP Stage-I. The layout of the
powerhouse complex is shown in PLAN Longitudinal Section along the powerhouse complex is
shown in PLAN
CHAPTER 3
SPECIFICATION
LOCATION State
District
Longitude
Latitude
Jammu & Kashmir
Ramban
75*18‟10” – 75*20‟s
33*9‟30” – 33*11‟
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HYDROLOGY Name of the River
Type of Scheme
Design Flood (PMF)
Diversion Flood (1:25 year)
Maximum and minimum
temperature in summer
Maximum and minimum
temperature in winter
Full Reservoir Level
Chenab
Run-of-the-river
16,500 cumec
3000 cumec
42*c 20*c
15*c and 1*c
840m
RESERVOIR Minimum Draw Down Level
Before Stage – 2
After Stage – 2
Gross Storage upto FRL
Live Storage Capacity
838m
836m
475 Million m
15 Million m
DAM Type
Length
Height (from deepest foundation
level)
Road level at top
Solid gravity concrete dam
362.862m
143.0m
843.0m
(SULICE TYPE) Location
Design Flood
Spillway Crest Elevation
Number of Spillway bays
Size of gate
Type of gate
River bed portion
10,667 cumec
808m
5 Nos.
10.0m(W)x10.5m(H)
Radial gates with Hydraulic
Hoists
CHUTE SPILLWAY Location
Design Flood
Crest Elevation
Number of bays
Size of gate
Type of gate
On left flank
5790 cumec
821.0m
3 Nos.
12m(W)x19m(H)
Radial gates with Hydraulic
Hoists
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AUXILIARY SPILLWAY Crest Elevation
Design Flood
Number of bays
Size of gate
Type of gate
837.0m
60 cumec
One
6.0m(W)x3.0mH)
Fixed Wheel Gate
DIVERSION TUNNELS Location
Number
Finished Size
Shape
Length DT-1 , DT-2
Diversion Capacity
Invert setting:
DT-1
DT-2
Construction adit & cross adits for
approaching diversion tunnels
On right bank
Two
10.481m(W)x10.637m(H)
Horse Shoe with flSat invert
360M ,515M.
3000 cumec
Inlet end
EI. 710.0m
EI. 710.5m
7.5m D-shaped construction adit
265m long
7.5m D-shaped , 4nos. Cross
adits
(3x30m+1x38m long)
NEW RIVER DIVERSION
ARRANGEMENT
i)6.8m diameter circular bottom
outlet.
ii) 4nos.temporary diversion sluices
of size 3.5m(W)*8.2m(H)
iii) Escape Channel (12m
wide*86.366long).Its height varies
from 8m at RD 200md/s of dam
axis.
It located in block # 11 at EI.
733 at Inlet ant EL. 732 at
outlet.
2nos.are located in block # 12 at
EI. 766 and 2nos. in block # 13
at EI. 763.S
It is located at d/s of lip of Hill
Side Chute Channel in block # 4.
INTAKE(FOR STAGE-1
WORKS)
Capacity
Sill Elevation
Openings – 2 Nos.
Type of Gates
.
430 cumec
EL 821.0m
10m(W)x705m(H)
Fixed wheel gates with
Hydraulic Hoists
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INTAKE(FOR STAGE-2
WORKS)
Capacity
Sill Elevation
Openings
Type of Gates
430 cumec
EL 821.0m
10m(W)x7.5m(H)
Fixed wheel gates with
Hydraulic Hoists
HEAD RACE TAIL
TUNNEL
Number
Size and Shape
Length
Discharge
Invert level at intake(After vertical
S-Curve)
Invert level at junction with surge
shaft
ONE
10.15 m dia Circular
2075.37m(sloping Length upto
centre of Orifice)
430cumec
815.133m
775.35m
SURGE SHAFT Location
Type
Size
Height
Emergency Gates
Upstream of powerhouse(fully
underground approach to top
through an access cum airvent
adit)
Restricted Orifice Type
27.5m dia.
77m
Fixed wheel gates(Bonnet Type)
with Hydraulic Hoists for each
pressure shaft located in gate
chamber downstream of surge
Shaft
PRESSURE
SHAFTS/PENSTOCKS
Number
Shape
Size
Length(from centre of orfice upto
u/s wall of Machine hall)
Three
Circular
5.5m dia
No. 1 224.166m
No.2 206.936m
NO.3 202.116m
ACCESS TUNNEL TO
POWERHOUSE
Size
Length
7.5m D-Shaped
354.8m
15
(Outdoor Pothead yard) Size 120mx30m (Combined for
Stage-I & II)
TAILRACE TUNNEL Shape
Size
Length
Discharge
D- Shaped
9m (W) x 19 to 27.5m (H)
130m
430 cumec
POWER PLANT
EQUIPMENT
Turbines
M.I Valves
Hydro-generators
Transformers
Switchgear
E.O.T Cranes
Francis
Butterfly type located in
Machine Hall
Vertical shaft, synchronous
generator. 166.67 MVA
Corresponding to turbine rated
output of 150 MW. RPM 187.5
50Hz.
Epoxy type. Class F insulation
11kw/400kv single phase
transformers (10 nos. including
one spare transformer)
400kv SF3 gas insulated switch
gear comprising 6 bays (3
incoming. 2 transmission line
bays and one bus coupler bay)
2 nos. Cranes with Lifting Beam
POWER OUTPUT Installed Capacity
Minimum discharge in 90%
available year
Minimum mean Discharge
Firm power(based on minimum
mean discharge)
Annual energy generation
90% availability year
50% availability year(maen year)
3x150 MW
119 cumec
131 cumec
141 MW
2643 GWH
2699 GWH
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CHAPTER 4
EQUIPMENTS USED
Dump Truck
Dump trucks or production trucks are those that are used for transporting loose material such as
sand, dirt, and gravel for construction. The typical dump truck is equipped with a hydraulically
operated open box bed hinged at the rear, with the front being able to be lifted up to allow the
contents to fall out on the ground at the site of delivery. Dump trucks come in many different
configurations with each one specified to accomplish a specific task in the construction chain.
Standard dump truck
The standard dump truck is a full truck chassis with the dump body mounted onto the frame. The
dump body is raised by a hydraulic ram lift that is mounted forward of the front bulkhead,
normally between the truck cab and the dump body. The standard dump truck also has one front
axle, and one or more rear axles which normally has dual wheels on each side. The common
configurations for standard dump trucks include the six wheeler and ten wheeler.
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Transfer dump truck
For the amount of noise made when transferring, the transfer dump truck is easy to recognize.
It‟s a standard dump truck that pulls a separate trailer which can be loaded with sand, asphalt,
gravel, dirt, etc. The B box or aggregate container on the trailer is
powered by an electric motor and rides on wheels and rolls off of the trailer and into the main
dump box. The biggest advantage with this configuration is to maximize payload capacity
without having to sacrifice the maneuverability of the short and nimble dump truck standards.
Semi trailer end dump truck
The semi end dump truck is a tractor trailer combination where the trailer itself contains the
hydraulic hoist. The average semi end dump truck has a 3 axle tractor that pulls a 2 axle semi
trailer. The advantage to having a semi end dump truck is rapid unloading.
Semi trailer bottom dump truck
A bottom dump truck is a 3 axle tractor that pulls a 2 axle trailer with a clam shell type dump
gate in the belly of the trailer. The biggest advantage of a semi bottom dump truck is the ability
to lay material in a wind row. This type of truck is also maneuverable in reverse as well, unlike
the double and triple trailer configurations.
Double and triple trailer
The double and triple bottom dump trucks consist of a 2 axle tractor pulling a semi axle semi
trailer and an additional trailer. These types of dump trucks allow the driver to lay material in
wind rows without having to leave the cab or stop the truck. The biggest disadvantage is the
difficulty in going in reverse.
Side dump trucks
Side dump trucks consist of a 3 axle trailer pulling a 2 axle semi trailer. It offers hydraulic rams
that tilt the dump body onto the side, which spills the material to the left or right side of the
trailer. The biggest advantages with these types of dump trucks are that they allow rapid
unloading and carry more weight than other dump trucks.
In addition to this, side dump trucks are almost impossible to tip over while dumping, unlike the
semi end dump trucks which are very prone to being upset or tipped over. The length of these
trucks impede maneuverability and limit versatility.
Off road dump trucks
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off road trucks resemble heavy construction equipment more than they do highway dump trucks.
They are used strictly for off road mining and heavy dirt hauling jobs, such as excavation work.
They are very big in size, and perfect for those time when you need to dig out roads and need
something to haul the massive amounts of dirt to another location.
Front Loader
Also known as a front end loader, bucket loader, scoop loader, or shovel, the front loader is a
type of tractor that is normally wheeled and uses a wide square tilting bucket on the end of
movable arms to lift and move material around. The loader assembly may be a removable
attachment or permanently mounted on the vehicle. Often times, the bucket can be replaced with
other devices or tools, such as forks or a hydraulically operated bucket.
Larger style front loaders, such as the Caterpillar 950G or the Volvo L120E, normally have only
a front bucket and are known as front loaders, where the small front loaders are often times
equipped with a small backhoe as well and called backhoe loaders or loader backhoes. Loaders
are primarily used for loading materials into trucks, laying pipe, clearing rubble, and also
digging. Loaders aren‟t the most efficient machines for digging, as they can‟t dig very deep
below the level of their wheels, like the backhoe can.
The deep bucket on the front loader can normally store around 3 – 6 cubic meters of dirt, as the
bucket capacity of the loader is much bigger than the bucket capacity of a backhoe loader.
Loaders aren‟t classified as excavating machinery, as their primary purpose is other than moving
dirt. In construction areas, mainly when fixing roads in the middle of the city, front loaders are
used to transport building materials such as pipe, bricks, metal bars, and digging tools. Front
loaders are also very useful for snow removal as well, as you can use their bucket or as a snow
plow. They can clear snow from the streets and highways, even parking lots. They will
sometimes load the snow into dump trucks which will then haul it away.
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Unlike the bulldozer, most loaders are wheeled and not tracked. The wheels will provide better
mobility and speed and won‟t damage paved roads near as much as tracks, although this will
come at the cost of reduced traction. Unlike backhoes or tractors fitted with a steel bucket, large
loaders don‟t use automotive steering mechanisms, as they instead steer by a hydraulically
actuated pivot point set exactly between the front and rear axles. This is known as articulated
steering and will allow the front axle to be solid, therefore allowing it to carry a heavier weight.
Articulated steering will also give a reduced turn in radius for a given wheelbase. With the
front wheels and attachment rotating on the same axis, the operator is able to steer his load in an
arc after positioning the machine, which can come in quite handy. The problem is that when the
machine is twisted to one side and a heavy load is lifted high in the air, it has a bigger risk of
turning over.
Various Types Of Cranes
A crane is a tower or derrick that is equipped with cables and pulleys that are used to lift and
lower material. They are commonly used in the construction industry and in the manufacturing
of heavy equipment. Cranes for construction are normally temporary
structures, either fixed to the ground or mounted on a purpose built vehicle.
They can either be controlled from an operator in a cab that travels along with the crane, by a
push button pendant control station, or by radio type controls. The crane operator is ultimately
responsible for the safety of the crews and the crane.
Mobile Cranes
The most basic type of crane consists of a steel truss or telescopic boom mounted on a mobile
platform, which could be a rail, wheeled, or even on a cat truck. The boom is hinged at the
bottom and can be either raised or lowered by cables or hydraulic cylinders.
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Telescopic Crane
This type of crane offers a boom that consists of a number of tubes fitted one inside of the other.
A hydraulic mechanism extends or retracts the tubes to increase or decrease the length of the
boom.
Tower Crane
The tower crane is a modern form of a balance crane. When fixed to the ground, tower cranes
will often give the best combination of height and lifting capacity and are also used when
constructing tall buildings.
Truck Mounted Crane
Cranes mounted on a rubber tire truck will provide great mobility. Outriggers that extend
vertically or horizontally are used to level and stabilize the crane during hoisting.
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Loader Crane
A loader crane is a hydraulically powered articulated arm fitted to a trailer, used to load
equipment onto a trailer. The numerous sections can be folded into a small space when the crane
isn‟t in use.
Overhead Crane
Also refered to as a suspended crane, this type is normally used in a factory, with some of them
being able to lift very heavy loads. The hoist is set on a trolley which will move in one direction
along one or two beams, which move at angles to that direction along elevated or ground level
tracks, often mounted along the side of an assembly area.
22
In the excavation world, cranes are used to move equipment or machinery. Cranes can quickly
and easily move machinery into trenches or down steep hills, or even pipe. There are many types
of cranes available, serving everything from excavation to road work.
Cranes are also beneficial to building bridges or construction. For many years, cranes have
proven to be an asset to the industry of construction and excavating. Crane operators make really
good money, no matter what type of crane they are operating.
Compact Excavator
The compact hydraulic excavator can be a tracked or wheeled vehicle with an approximate
operating weight of 13,300 pounds. Normally, it includes a standard backfill blade and features
an independent boom swing. The compact hydraulic excavator is also known as a mini
excavator.
A compact hydraulic excavator is different from other types of heavy machinery in the sense that
all movement and functions of the machine are accomplished through the transfer of hydraulic
fluid. The work group and blade are activated by hydraulic fluid acting upon hydraulic cylinders.
The rotation and travel functions are also activated by hydraulic fluid powering hydraulic
motors.
Most types of compact hydraulic excavators have three assemblies – house, undercarriage, and
the work group.
23
House
The house structure contains the compartment for the operator, engine compartment, hydraulic
pump and also the distribution components. The house structure is attached to the top of the
undercarriage via swing bearing. Along with the work group, them house is able to rotate upon
the undercarriage without limit due to a hydraulic distribution valve that supplies oil to the
undercarriage components.
Undercarriage
The undercarriage of compact excavators consists of rubber or steel tracks, drive sprockets,
rollers, idlers, and associated components and structures. The undercarriage is also home to the
house structure and the work group.
Work group
The work group consists of the boom, dipper or arm, and attachment. It is connected to the front
of the house structure via a swinging frame that allows the work group to be hydraulically
pivoted left or right in order to achieve offset digging for trenching parallel with the tracks.
Independent boom swing
The purpose of the boom swing is for offset digging around obstacles or along foundations,
walls, and forms. Another use is for cycling in areas that are too narrow for cab rotation. Another
major advantage of the compact excavator is the independent boom swing.
Backfill blade
The backfill blade on compact excavators are used for grading, leveling, backfilling, trenching,
24
and general dozer work. The blade can also be used to increase the dumping height and digging
depth depending on it‟s position in relation to the workgroup.
The most common place you‟ll find compact excavators is in residential dwellings. When
digging phone lines or other things, these pieces of equipment are very common for getting
between houses. Due to their small size, they can fit almost anywhere. Over the years, the
capabilities for compact excavators have expanded far beyond the tasks of excavation. With
hydraulic powered attachments such as breakers, clamps, compactors and augers, the compact
excavator is used with many other applications and serves as an effective attachment tool as well.
Serving many purposes, the compact excavator is a great addition to any job that requires the use
of machinery.
Bulldozer
The bulldozer is a very powerful crawler that is equipped with a blade. The term bulldozer is
often used to mean any type of heavy machinery, although the term actually refers to a tractor
that is fitted with a dozer blade. Often times, bulldozers are large and extremely powerful tracked
vehicles. The tracks give them amazing ground mobility and hold through very rough terrain.
Wide tracks on the other hand, help to distribute the weight of the dozer over large areas,
therefore preventing it from sinking into sandy or muddy ground.
Bulldozers have great ground hold and a torque divider that‟s designed to convert the power of
the engine into dragging ability, which allows it to use its own weight to push heavy objects and
even remove things from the ground. Take the Caterpillar D9 for example; it can easily tow
tanks that weight more than 70 tons. Due to these attributes, bulldozers are used to clear
obstacles, shrubbery and remains of structures and buildings.
The blade on a bulldozer is the heavy piece of metal plate that is installed on the front. The
blade pushes things around. Normally, the blade comes in 3 varieties:
1. A straight blade that is short and has no lateral curve, no side wings, and can be used
only for fine grading.
2. A universal blade, or U blade, which is tall and very curved, and features large side wings to
carry more material around.
3. A combination blade that is shorter,offers less curvature, and smaller side wings.
25
Modifications
Over time, bulldozers have been modified to evolve into new machines that are capable of things
the original bulldozers weren‟t. A good example is that loader tractors were created by removing
the blade and substituting a large volume bucket and hydraulic arms which will raise and lower
the bucket, therefore making it useful for scooping up the earth and loading it into trucks. Other
modifications to the original bulldozer include making it smaller to where it can operate in small
working areas where movement is very limited, such as mining caves and tunnels. Very small
bulldozers are known as calfdozers.
History
The first types of bulldozers were adapted from farm tractors that were used to plough fields. In
order to dig canals, raise earth dams, and partake in earthmoving jobs, the tractors were equipped
with a thick metal plate in the front. Later on, this thick metal plate earned the name blade.
The blade of the bulldozer peels layers of soil and pushes it forward as the tractor advances. The
blade is the heart and soul of the bulldozer, as it was the first accessory to make full use for
excavation type jobs. As the years went by, when engineers needed equipment to complete larger
jobs, companies such as CAT, Komatsu, John Deere, Case, and JCB started to manufacture large
26
tracked earthmoving equipment. They were very loud, very large, and very powerful and
therefore earned the nickname “bulldozer”. Over the years, the bulldozers got bigger, more
powerful, and even more sophisticated. The important improvements include better engines,
more reliable drive trains, better tracks, and even hydraulic arms that will enable more precise
manipulation of the blade and automated controls.As an added option, bulldozers can come
equipped with a rear ripping claw to break up pavement or loosen rocky soil.The best known
manufacturer of bulldozer is CAT,which has earned a vast reputation for making
tough and durable, yet reliable machines.Even though the bulldozer started off a modified
farmtractor, it rapidly became one of the most useful pieces of equipment with excavating and
construction.
Backhoe Loader
Also referred to as a loader backhoe, the backhoe loader is an engineering and excavation vehicle
that consists of a tractor, front shovel and bucket and a small backhoe in the rear end. Due to the
small size and versatility, backhoe loaders are common with small construction projects and
excavation type work. Originally invented in Burlington Iowa back in 1857, the backhoe loader
is the most common variation of the classic farm tractor .As the name implies, it has a loader
assembly on the front and a backhoe attachment on the back.
Anytime the loader and backhoe are attached it is never referred to as a tractor, as it is not
normally used for towing and doesn‟t normally have a PTO. When the backhoe is permanently
attached, the machine will normally have a seat that can swivel to the rear to face the backhoe
controls. Any type of removable backhoe attachments will normally have a separate seat on the
attachment itself. Backhoe loaders are common and can be used for many tasks, which include
construction, light transportation of materials, powering building equipment, digging holes and
excavating, breaking asphalt, and even paving roads. You can often replace the backhoe bucket
with other tools such as a breaker for breaking and smashing concrete and rock. There are some
loader buckets that offer a retractable bottom, which enable it to empty the load more quickly
and efficiently.
27
The retractable bottom loader buckets are often times used for grading and scratching off
sand.The front assembly on a backhoe may be either removable or permanently attached. Often
times,the bucket can be replaced with other tools or devices. In order to mount different
attachments to the loader, it must be equipped with a tool coupler. The coupler consists of two
hydraulic cylinders on the end of the arm assembly, which can expand and retract to allow
different tools to be attached to the unit. There are several types of backhoe loader brands,
including New Holland, John Deere, and Case. Some will offer you cabs, while others won‟t.
The newer types of backhoe loaders even offer you air conditioning, radios, and other
accessories that make you feel like you are working with luxury. Common with excavating jobs,
the backhoe can serve many purposes. It can haul equipment and supplies in the loader bucket.
Another great use is to cover up dirt when filling in trench lines or covering up pipe that was just
put in the ground. The backhoe attachment at the rear is ideal for digging water pipes and sewer
pipes. The best thing about the backhoe loader is the fact that they are easy to operate. You don‟t
need to be a rocket scientist to fully operate this nifty piece of equipment.
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CHAPTER 5
HEAD RACE TUNNEL
It is a 2080m long 10.15m dia. concrete lined and grouted circular water conductor system to
carry a design of 430 cumecs. with a maximum velocity of 5.28m/sec. It has been constructed by
conventional method of drilling blasting and mucking. The shape of head race tunnel (HRT) is
circular.
SURGE SHAFT
A restricted orifice type surge shaft has been provided at the end of HRT. The surge shaft is 77m
high having 27.5m finished diameter. The area for the orifice is provided by an opening of 6.14m
dia. In orifice slab. The surge shaft is fully under ground. The approach adit cum air vent of
308m in length. The three turbines of the powerhouse are fed through separate pressure shafts of
5.5m dia. each starting from the bottom of the surge shaft. The pressure shafts negotiable a drop
of 84.425m between center line of HRT at junction with the surge shaft at EL 780.425 and
29
centerline of machine EL 696m. The length of pressured shafts PS #1, PS # 2 & PS #3 is
215m,196m and 193m respectively.
Penstock
The penstock is a pipe that carries water from the intake to the turbine. Most hydropower system
will include some type of penstock. Depending on the site characteristics, the pen stock length
any range from a few feet for manmade structure with an open flume. This type of site has no
penstock. Developers with an open flume leading to the turbine can proceed to the next section.
If you have received a penstock recommendation from the turbine manufacturer, you should
contact suppliers to obtain pipe specification and pricing information. If you plan to follow the
turbine manufacturer‟s recommendation, you should review the contents of this section before
ordering the pipe in order to facilitate making a design layout of the penstock and to make sure
that you have considered all materials and costs.
The following are the some of the major factors that must be considered in selecting a penstock
route:
Accessibility. The route should be accessible to personnel and equipment required for
pipe installation, inspection, and maintenance. In those areas where equipment access is
difficult or impossible, installation and maintenance must be performed manually.
30
Soil Conditions. Soils along the pipeline should be examined to identify rock
outcropping, soft or unstable soils , or other characteristics that would interfere with
penstock installation or damage the penstock.
Natural or Man-Made Obstructions. These include trees, roadways, buildings, stream
crossing, and other features that require special care.
Gradient. The penstock is best routed to take advantage of the natural downward
gradient. If the line cannot be located so as to have a constant downward gradient, an air
relief valve or equivalent device is required at very local high point, and a drain valve is
required at very local low point.
Above or Below-Ground Installation. A buried penstock has certain advantages over an
above-ground installations. Anchoring and supporting the pipe are simplified, ultraviolet
radiation effects on PVC pipe are eliminated, and the effects of weather (thermal
expansion, freezing) are reduced. In addition, physical damage to the pipe from falling
rocks and trees or other sources is also prevented. On the other hand, and above –ground
pipe will have a lower construction cost, may allow for more direct routing (fewer
bends), and is readily accessible for inspection or repair. Another alternative is to have a
combination of above and below ground installation.
Material Selection:
The turbine manufacturer may have recommended a certain material for penstock. You
may want to consider other material that might be less expensive. The most common
materials include:
PVC (polyvinyl chloride)
Steel
Polyethylene
FRE (fiber reinforced epoxy)
Transite (asbestos cement)
31
Cost
Availability
Physical properties (friction , strength , chemistry)
Joining methods and installation limitations.
Penstock Sizing:
A satisfactory penstock diameter depends on three factors:
Energy (head) losses due to friction between the water flowing in the pipe and the inside
pipe wall.
Pressure limitations of the pipe as a function of wall thickness.
Cost of the pipe and installation.
In this dam we use three penstocks. It is circular in shape, having diameter 5.5m and length of
penstock(from center of Orifice up to u/s wall of Machine
Hall)are(i)224.166m(ii)206.936m(iii)202.116m.
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CHAPTER 6
TAIL RACE TUNNEL
Tailrace
A tailrace is a canal or conduit that carries water from the powerhouse to the next
desired location (usually back into the stream).
Size of the Tailrace
33
The tailrace should be large enough to carry the design flow. The velocity in the tailrace
can be 2 fps. In parts of the country where fish migration is a consideration, the velocity at the
tailrace exit should be reduced to less than 0.5 fps. Migrating fish will be attracted into the
tailrace if the velocity is too high.
For sizing the tailrace for 2 fps, refer to section on power canals, Subsection 4.4.2.2. The
power canal and tailrace will have the same cross-sectional area. Note that the slope for the
tailrace must also be equal or greater than that of the power canal. If the reduced velocity is
needed at the stream entrance, make the end of the tailrace four times wider. If the same depth
is maintained, the velocity will be reduced to
0.5 fps.
Tail race Intake
Generally, the tailrace will start below the powerhouse and is an integral part of the
powerhouse design. The width and depth is set by the area for 2 fps. The powerhouse footings
and the tailrace intake are usually constructed from concrete. The concrete can either be precast
or poured in place.
In this project tail race system of a collection gallery of size 12.5m (W) x 44m (H) x 75m
(L),tail race tunnel of 130m length and outlet structure. The collection gallery also functions as
downstream surge chamber. The draft tube gates located at the junctions of draft tube tunnels
with collection gallery are operated from collection gallery at EL 726m which is 10m above the
roof of collection gallery. The 130m long concrete lined tail race tunnel is 9m wide and meets
the outfall structures at EL 700m(meters above sea level).Consult to plan of TRT for actual
parameretrs.
34
35
CHAPTER 7
SURVEYING
TOTAL STATION INSTRUMENT
While working in BHEP Under JayPee construction ltd. As per our schedule we have to work
under surveying department for few days but because of bad weather condition (rain) we weren‟t
able to work as much in field as we want so our training was limited to just instrument setup.
INTRODUCTION
In the past, transits and theodolites were the most commonly used surveying instruments
For making angle observations. These two devices were fundamentally
Equivalent and could accomplish basically the same tasks. Today, the total station
Instrument has replaced transits and theodolites. Total station instruments can
Accomplish all of the tasks that could be done with transits and theodolites and do
Them much more efficiently. In addition, they can also observe distances accurately
And quickly. Furthermore, they can make computations with the angle and
Distance observations, and display the results in real time. These and many other
significant advantages have made total stations the predominant instruments used
in surveying practice today.They are used for all types of surveys including topographic,
hydrographic, cadastral, and construction surveys.
36
To use the total station, it is set over one end of the line to be measured and
some reflector is positioned at the other end such that the line of sight between
the instrument and the reflector is unobstructed.
-The reflector is a prism attached to a detail pole
-The telescope is aligned and pointed at the prism
-The measuring sequence is initiated and a signal is sent to the reflector and a
part of this signal is returned to the total station
-This signal is then analysed to calculate the slope distance together with the
horizontal and vertical angles.
-Total stations can also be used without reflectors and the telescope is pointed at
the point that needs to be measured
-Some instruments have motorised drivers and can be use automatic target
recognition to search and lock into a prism – this is a fully automated process and
does not require an operator.
-Some total stations can be controlled from the detail pole, enabling surveys to
be conducted by one person..A total station is levelled and centred in the same way as a
theodolite.Most total stations have a distance measuring range of up to a few kilometres,
when using a prism, and a range of at least 100m in reflector less mode and an
accuracy of 2-3mm at short ranges, which will decrease to about 4-5mm at 1km. Although
angles and distances can be measured and used separately, the most
37
common applications for total stations occur when these are combined to define
position in control surveys.
Handaling of total station
A total station instrument should be carefully lifted from its carrying case by
grasping the standards or handle, and the instrument securely fastened to the tripod
by means of the tribrach. For most surveys, prior to observing distances and
angles, the instrument must first be carefully set up over a specific point.The setup
process using an instrument with an optical plummet, tribrach mount with circular
bubble, and adjustable-leg tripod is accomplished most easily using the following
steps: (1) extend the legs so that the scope of the instrument will be at an appropriate
elevation for view and then adjust the position of the tripod legs by lifting and
moving the tripod as a whole until the point is roughly centered beneath the tripod
head (beginners can drop a stone from the center of the tripod head, or use a
plumb bob to check nearness to the point); (2) firmly place the legs of the tripod in
the ground and extend the legs so that the head of the tripod is approximately
level; repeat step (1) if the tripod head is not roughly centered over the point;
(3) roughly center the tribrach leveling screws on their posts; (4) mount the tribrach
approximately in the middle of the tripod head to permit maximum translation in
step (9) in any direction; (5) focus the plummet properly on the point, making sure
to check for parallax; (6) manipulate the leveling screws to aim the plummet‟s
pointing device at the point below; (7) center the circular bubble by adjusting the
lengths of the tripod extension legs; (8) and level the instrument using the plate
bubble and leveling screws; and (9) if necessary, loosen the tribrach screw and
translate the instrument (do not rotate it) to carefully center the plummet‟s pointing
device on the point; (10) repeat steps (8) and (9) until precise leveling and
centering are accomplished.With total stations that have their plummets in the
tribrach, the instrument can and should be left in the case until step (8).
To level a total station instrument that has a plate-level vial, the telescope is
rotated to place the axis of the level vial parallel to the line through any two leveling
screws, as the line through A and B.The bubble is centered
leveling
screws, as the line through A and B.The bubble is centeredby turning these two screws, then
rotated 90°, as shown in Figure, and centered again using the third screw (C) only. This process
is repeated in the initial two positions and carefully checked to ensure that the bubble remains
centered. As illustrated in, the bubble moves in the direction of the left thumb when the foot
screws are turned.A solid tripod setup is essential, and the instrument must be shaded if set up in
38
bright sunlight. Otherwise, the bubble will expand and run toward the warmer end as the liquid is
heated. Many instruments, such as the LEICA TPS 300, do not have traditional level vials.
Rather, they are equipped with an electronic, dualaxis leveling system in which four probes sense
a liquid (horizontal) surface. After preliminary leveling is performed by means of the tribrach‟s
circular bubble, signals from the probes are processed to form an image on the LCD display,
which guides an operator in performing rough leveling.The three leveling screws are used, but
the instrument need not be turned about its vertical axis in the leveling process. After rough
leveling, the amount and direction of any residual dislevelment is automatically and continuously
received by the microprocessor, which corrects observed horizontal and vertical angles
accordingly in real time. As noted earlier, total stations are controlled with entries made either
through their built-in keypads or through the keypads of handheld data collectors. Details for
operating each individual total station vary somewhat and therefore are not described here. They
are covered in the manuals provided with the purchase of instruments. When moving between
setups in the field, proper care should be taken. Before the total station is removed from the
tripod, the foot screws should be returned to the midpoints of the posts. Many instruments have a
line on the screw post that indicates the halfway position. The instrument should NEVER be
transported on the tripod since this causes stress to tripod head, tribrach, and instrument base.
depicts the proper procedure for carrying equipment in the field.With adjustable-leg tripods,
retracting them to their shortest positions and lightly clamping them in position can avoid stress
on the legs. When returning the total station to its case, all locking mechanisms should
be released. This procedure protects the threads and reduces wear when the instrument
is jostled during transport and also prevents the threads from seizing during long periods of
storage. If the instrument is wet, it should be wiped down and left in an open case until it is dry
.When storing tripods, it is important to loosen or lightly clamp all legs. This is especially true
with wooden tripods where the wood tends to expand and contract with humidity in the air.
Failure to loosen the clamping mechanism on wooden tripods can result in crushed wood fibers,
which inhibit the ability of the clamp to hold the leg during future use.
Coordinate measurement
Coordinates of an unknown point relative to a known coordinate can be determined using the
total station as long as a direct line of sight can be established between the two points. Angles
and distances are measured from the total station to points under survey, and the coordinates (X,
Y, and Z or easting, northing and elevation) of surveyed points relative to the total station
position are calculated using trigonometry and triangulation. To determine an absolute location a
Total Station requires line of sight observations and must be set up over a known point or with
line of sight to 2 or more points with known location.
39
For this reason, some total stations also have a Global Navigation Satellite System receiver and
do not require a direct line of sight to determine coordinates. However, GNSS measurements
may require longer occupation periods and offer relatively poor accuracy in the vertical axis.
Angle measurement
Most modern total station instruments measure angles by means of electro-optical scanning of
extremely precise digital bar-codes etched on rotating glass cylinders or discs within the
instrument. The best quality total stations are capable of measuring angles to 0.5 arc-second.
Inexpensive "construction grade" total stations can generally measure angles to 5 or 10 arc-
seconds.
Distance measurement
Measurement of distance is accomplished with a modulated microwave or infrared carrier signal,
generated by a small solid-state emitter within the instrument's optical path, and reflected by a
prism reflector or the object under survey. The modulation pattern in the returning signal is read
and interpreted by the computer in the total station. The distance is determined by emitting and
receiving multiple frequencies, and determining the integer number of wavelengths to the target
for each frequency. Most total stations use purpose-built glass corner cube prism reflectors for
the EDM signal. A typical total station can measure distances with an accuracy of about 1.5
millimetres (0.0049 ft) + 2 parts per million over a distance of up to 1,500 metres (4,900 ft).
Reflectorless total stations can measure distances to any object that is reasonably light in color,
up to a few hundred meters.
Data processing
Some models include internal electronic data storage to record distance, horizontal angle, and
vertical angle measured, while other models are equipped to write these measurements to an
external data collector, such as a hand-held computer.
40
When data is downloaded from a total station onto a computer, application software can be used
to compute results and generate a map of the surveyed area. The new generation of total stations
can also show the map on the touch-screen of the instrument right after measuring the points.
CHAPTER 8
Quality Control lab
As per the schedule we have to work for few days in quality control laboratory to understand the
strength and other parameters of material used.
Here are the few tests that we performed in the quality control lab.
Lab tests on Cement:
DETERMINATION OF COMPRESSIVE STRENGTH OF CEMENT.
(IS: 4031 – Part – 6)
Object:
Determination of the compressive strength of standard cement mortar cubes compacted by means
of a standard vibration machine.
Apparatus:
Vibration machine, cube moulds of size 7.06 cms(confirming to IS : 4031 – 1968), and Standard
Sand to be used in the test shall be confirm to IS : 650 – 1966.
Procedure:
Mix Proportions and Mixing: Clean appliances shall be used for mixing and the temperature of
the water and that of the test room at the time when the above operations are being performed
shall be 270 +/- 2
0C. Place in a container a mixture of cement and standard sand in the proportion
of 1 : 3 by weight; mix it dry, with a trowel for one minute and then with water until the mixture
is of uniform colour. The quantity of water to be used shall be as specified below. In any event, it
should not take more than 4 minutes to obtain uniform colored mix. If it exceeds 4 minutes, the
mixture shall be rejected and the operation repeated with a fresh quantity of cement, sand and
water.
41
The material for each cube shall be mixed separately and the quantity of cement, standard sand
and water shall be as follows: Percentage of water to be added to the cement and sand in ( 1:3 )
cm (P/4 + 3) X % combined weight of cement and sand = (P/4 + 3) X 800/100.
Cement 200 gms, standard sand 600 gms, water (P/4 + 3) per cent of combined weight of cement
and sand, where P is the percentage of water required to produce a paste of standard consistency.
Molding Specimens:
In assembling the moulds ready for use, cover the joints between the halves of the mould with a
thin film of petroleum jelly and apply a similar coating of petroleum jelly between the contact
surfaces of the bottom of the mould and its base plate in order to ensure that no water escapes
during vibration. Treat the interior faces of the mould with a thin coating of mould oil. Place the
assembled mould on the table of the vibration machine and firmly hold it in position by means of
suitable clamps. Securely attach a Hooper of suitable size and shape at the top of the mould to
facilitate filling and this Hooper shall not be removed until completion of the vibration.
Immediately after mixing the mortar, place the mortar in the cube mould and rod with a rod. The
mortar shall be rodded 20 times in about 8 seconds to ensure elimination of entrained air and
honey combing. Place the remaining quantity of mortar in the Hooper of the cube mould and rod
again as specified for the first layer and then compact the mortar by vibration. The period of
vibration shall be two minutes at the specified speed of 12000 +/- 400 vibrations per minutes. At
the end of vibration remove the mould together with the base plate from the machine and finish
the top surface of the cube in the mould by smoothing surface with the blade of a trowel.
Curing Specimens:
Keep the filled moulds at a temperature of 270C +/- 2
0C in an atmosphere of at least 90% relative
humidity for about 24 hours after completion of vibration. At the end of that period remove them
from the moulds immediately submerge in clean fresh water and keep them under water until
testing. The water in which the cubes are submerged shall be renewed every 7 days and shall be
maintained at a temperature of 270C +/- 2
0C. After they have been taken out and until they are
tested, the cubes shall not be allowed to become dry.
Testing:
Test three cubes for compressive strength at the periods mentioned under the relevant
specifications for different hydraulic cements, the periods being reckoned from the completion of
vibration. The compressive strength shall be the average of the strengths of the three cubes for
each period of curing. The cubes shall be tested on their sides without any packing between the
42
cube and the steel platens of the testing machine. One of the platens shall be carried base and
shall be self-adjusting and the load shall be steadily and uniformly applied, starting from zero at
a rate of 350 kgs/cm2/min.
Calculation:
Calculate the compressive strength from the crushing load and the average area over which the
load is applied. Express the results in kgs/cm2 to the nearest 0.5 kg/cm
2.
Compressive strength, kg/cm2 = P/A, where „P‟ is the crushing load in kg, and „A‟ is the area in
cm2.
FINENESS BY DRY SIEVING REFERENCE: IS 4031 – (PART – 1)
1996
IMPORTANCE:
During manufacturing, cement must be ground to be uniformly fine
Otherwise concrete needs large amount of water for mixing which results in bleeding as
well as poor workmanship.
Test sieve of non-corrodible metal having 150 mm to 200 mm dia, and 40 mm to
100 mm depth fitted with 90 µm mesh sieve cloth of woven stainless steel or
other abrasion resistant non- corrodible wires.
Suitable tray with lid to fit sieve size.
Stoppered jar with blunt ended stirrer rod
Weighing balance to weigh up to 10 gms to nearest 10 mg.
Nylon or pure bristle brush (25 mm / 40 mm bristles) for cleaning sieves.
43
PROCEDURE:
Determination of cement residue:
• Agitate the cement sample by shaking for 2 minutes in a stoppered jar to disperse the
agglomerates. Wait for few minutes.
• Stir the resulting powder gently with dry rod to distribute the fines throughout the sample.
• Weigh approx. 10 gm of cement and put in sieve fitted with bottom tray and top lid.
• Agitate and shake the sieve thoroughly
• Weigh the residue – retained on sieve.
• Clean base of sieve gently by brush to remove fine material.
• Find out % (R1) of residue in comparison with total weight of sample.
• Repeat the procedure at least twice till results do not differ by more than 1%.
CALCULATION
Find out mean of observations and express this percentage as R
CEMENT: DETERMINATION OF SETTING TIME REFERENCE:
IS 4031 – (PART – 5) 1996
44
IMPORTANCE OF TEST: The object is to distinguish between, quick setting and
normal setting time and to detect the deterioration due to storage.
APPARATUS
• Vicat Apparatus
• Balance (capacity 1000 gms, accuracy 0.1 gm)
• Annular attachment of Vicat Apparatus
TEMPERATURE & HUMIDITY
• Dry Materials, Water and Moulding Room : 27 + 2O C
• Relative Humidity in Laboratory : 65 + 5 %
PROCEDURE
On a non-porous platform
• Mix neat cement with enough water to give a paste of Standard
Consistency.
• Start stop watch immediately on adding water to cement. Note
Stop watch reading (To)
45
• Rest Vicat mould on non-porous plate and fill it completely with cement paste. Level of top
surface and expel air by shaking.
• Place test block with mould under the rod bearing needle of Vicat apparatus and b r ing rod
l eve l with t op o f test specimen. Release needle slowly and let it penetrate in the test block.
• Repeat the procedure until needle stops of distance of (5 + 0.5) mm from base of test block.
Read the stop watch and note the time (T1).
• Replace needle by annular attachment. Repeat procedure of releasing the needle till needle
makes an impression on top of test block while attachment fails to do so. Read the stop
watch and note time (T2).
CALCULATION
Initial Setting Time (IST) = (T1 – T0)
Final Setting Time (FST) = (T2 – T 0)
REPORTING
Report IST & FST to nearest 5 minutes
Lab Tests on Aggregates:
WATER ABSORPTION TEST
This test helps to determine the water absorption of coarse aggregates as per IS: 2386 (Part III) –
1963. For this test a sample not less than 2000g should be used. The apparatus used for this test
are :-
Wire basket – perforated, electroplated or plastic coated with wire hangers for suspending it from
46
the balance, Water-tight container for suspending the basket, Dry soft absorbent cloth – 75cm x
45cm (2 nos.), Shallow tray of minimum 650 sq.cm area, Air-tight container of a capacity similar
to the basket and Oven.
Procedure to determine water absorption of Aggregates.
i) The sample should be thoroughly washed to remove finer particles and dust, drained and then
placed in the wire basket and immersed in distilled water at a temperature between 22 and 32oC.
ii) After immersion, the entrapped air should be removed by lifting the basket and allowing it to
drop 25 times in 25 seconds. The basket and sample should remain immersed for a period of 24
+ ½ hrs afterwards.
iii) The basket and aggregates should then be removed from the water, allowed to drain for a few
minutes, after which the aggregates should be gently emptied from the basket on to one of the
dry clothes and gently surface-dried with the cloth, transferring it to a second dry cloth when the
first would remove no further moisture. The aggregates should be spread on the second cloth and
exposed to the atmosphere away from direct sunlight till it appears to be completely surface-dry.
The aggregates should be weighed (Weight „A‟).
iv) The aggregates should then be placed in an oven at a temperature of 100 to 110oC for 24hrs.
It should then be re moved from the oven, cooled and weighed (Weight „B‟).
Formula used is Water absorption = [(A - B)/B] x 100%.
Two such tests should be done and the individual and mean results should be reported. A sample
Performa for the record of the test is
47
AGGREGATE IMPACT VALUE
This test is done to determine the aggregate impact value of coarse aggregates as per IS: 2386
(Part IV) – 1963. The apparatus used for determining aggregate impact value of coarse
aggregates is
Impact testing machine conforming to IS: 2386 (Part IV)- 1963,IS Sieves of sizes – 12.5mm,
10mm and 2.36mm, A cylindrical metal measure of 75mm dia. and 50mm depth, A tamping rod
of 10mm circular cross section and 230mm length, rounded at one end and Oven.
Preparation of Sample
i) The test sample should conform to the following grading:
- Passing through 12.5mm IS Sieve – 100%
- Retention on 10mm IS Sieve – 100%
ii) The sample should be oven-dried for 4hrs. at a temperature of 100 to 110oC and cooled.
iii) The measure should be about one-third full with the prepared aggregates and tamped with 25
strokes of the tamping rod.
A further similar quantity of aggregates should be added and a further tamping of 25 strokes
given. The measure should finally be filled to overflow, tamped 25 times and the surplus
aggregates struck off, using a tamping rod as a straight edge. The net weight of the aggregates in
the measure should be determined to the nearest gram (Weight „A‟).
48
Procedure to determine Aggregate Impact Value
i) The cup of the impact testing machine should be fixed firmly in position on the base of the
machine and the whole of the test sample placed in it and compacted by 25 strokes of the
tamping rod.
ii) The hammer should be raised to 380mm above the upper surface of the aggregates in the cup
and allowed to fall freely onto the aggregates. The test sample should be subjected to a total of
15 such blows, each being delivered at an interval of not less than one second.
Reporting of Results
i) The sample should be removed and sieved through a 2.36mm IS Sieve. The fraction passing
through should be weighed (Weight „B‟). The fraction retained on the sieve should also be
weighed (Weight „C‟) and if the total weight (B+C) is less than the initial weight (A) by more
than one gram, the result should be discarded and a fresh test done.
ii) The ratio of the weight of the fines formed to the total sample weight should be expressed as a
percentage.
49
Aggregate impact value = (B/A) x 100%
iii) Two such tests should be carried out and the mean of the results should be reported.
AGGREGATE ABRASION VALUE
This test helps to determine the abrasion value of coarse aggregates as per IS: 2386 (Part IV) –
1963.
The apparatus used in this test are Los Angles abrasion testing machine, IS Sieve of size –
1.7mm, Abrasive charge – 12 nos. cast iron or steel spheres approximately 48mm dia. and each
weighing between 390 and 445g ensuring that the total weight of charge is 5000 +25g and Oven.
Sample Preparation
The test sample should consist of clean aggregates which has been dried in an oven at 105 to
110oC to a substantially constant weight and should conform to one of the gradings shown in the
table below:
50
Procedure to determine Aggregate Abrasion Value
The test sample and the abrasive charge should be placed in the Los Angles abrasion testing
machine and the machine rotated at a speed of 20 to 33 revolutions/minute for 1000 revolutions.
At the completion of the test, the material should be discharged and sieved through 1.70mm IS
Sieve.
Reporting of Results
i) The material coarser than 1.70mm IS Sieve should be washed, dried in an oven at a
temperature of 100 to 110oC to a constant weight and weighed (Weight „B‟).
ii) The proportion of loss between weight „A‟ and weight „B‟ of the test sample should be
expressed as a percentage of the original weight of the test sample. This value should be reported
as,
Aggregate abrasion value = (A-B)/B x 100
Flakiness index and Elongation Index of Coarse Aggregates
APPARATUS:
The apparatus for the shape tests consists of the following:
(i) A standard thickness gauge
(ii) A standard length gauge
(iii) IS sieves of sizes 63, 50 40, 31.5, 25, 20, 16, 12.5,10 and 6.3mm
(iv) A balance of capacity 5kg, readable and accurate up to 1 gm.
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THEORY:
The particle shape of aggregates is determined by the percentages of flaky and
elongated particles contained in it. For base course and construction of bituminous and
cement concrete types, the presence of flaky and elongated particles are considered
undesirable as these cause inherent weakness with possibilities of breaking down under
heavy loads. Thus, evaluation of shape of the particles, particularly with reference to
flakiness and elongation is necessary.
The Flakiness index of aggregates is the percentage by weight of particles whose
least dimension (thickness) is less than three- fifths (0.6times) of their mean dimension.
This test is not applicable to sizes smaller than 6.3mm.
The Elongation index of an aggregate is the percentage by weight of particles
whose greatest dimension (length) is greater than nine-fifths (1.8times) their mean
dimension. This test is not applicable for sizes smaller than 6.3mm.
PROCEDURE:
i) Sieve the sample through the IS sieves (as specified in the table).
ii) Take a minimum of 200 pieces of each fraction to be tested and weigh them.
iii) In order to separate the flaky materials, gauge each fraction for thickness on a
thickness gauge. The width of the slot used should be of the dimensions specified in
column (4) of the table for the appropriate size of the material.
iv) Weigh the flaky material passing the gauge to an accuracy of at least 0.1 per cent of
the test sample.
(v) In order to separate the elongated materials, gauge each fraction for length on a length
gauge. The width of the slot used should be of the dimensions specified in column (6)
of the table for the appropriate size of the material.
(vi) Weigh the elongated material retained on the gauge to an accuracy of at least 0.1 per
cent of the test sample.
Size of aggregates Weight of
fraction
Thickness
gauge
Weight of
aggregates
Length
gauge
Weight of
aggregates Passing Retained
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through
IS Sieve,
mm
on IS
Sieve,
mm
consisting
of at least
200
pieces,g
size, mm in each
fraction
passing
thickness
gauge,mm
size,
mm
in each
fraction
retained on
length
gauge,mm
1 2 3 4 5 6 7
63 50 W1 23.90 X1 - -
50 40 W2 27.00 X2 81.00 Y1
40 31.5 W3 19.50 X3 58.00 Y2
31.5 25 W4 16.95 X4 - -
25 20 W5 13.50 X5 40.5 Y3
20 16 W6 10.80 X6 32.4 Y4
16 12.5 W7 8.55 X7 25.5 Y5
12.5 10 W8 6.75 X8 20.2 Y6
10 6.3 W9 4.89 X9 14.7 Y7
Total W = X = Y =
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OBSERVATIONS:
Flakiness Index = (X1+ X2+…..) / (W1 + W2 + ….) X 100
Elongation Index = (Y1 + Y2 + …) / (W1 + W2 + ….) X 100
RESULT:
i) Flakiness Index =
ii) Elongation Index =
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Lab Tests on Concrete
DETERMINATION OF COMPRESSIVE STRENGTH OF
CONCRETE.
(IS: 516 – 1959)
Apparatus:
The testing machine may be of any reliable type of sufficient capacity for the tests and capable
of applying the load at the specified rate. The permissible error shall not be greater than 2 percent
of the maximum load. The testing machine shall be equipped with two steel bearing platens with
hardened faces. One of the platens shall be fitted with a ball seating in the form the portion of a
sphere, the center of which coincides with the central point of the face of the platen. The other
compression platen shall be plain rigid bearing block. The bearing faces of both platens shall be
at least as larger as, and preferably larger than the nominal size of the specimen to which the load
is applied. The bearing surface of the platens, when new, shall not depart from a plane by more
than 0.01mm at any point, and they shall be maintained with a permissible variation limit of
0.02mm. the movable portion of the spherical seated compression platen shall be held on the
spherical seat, but the design shall be such that the bearing face can be rotated freely and tilted
through small angles in any direction.
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Age at test: Tests shall be made at recognized ages of the test specimens, the most usual being 7
and 28 days. The ages shall be calculated from the time of the addition of water of the dry
ingredients.
Number of Specimens: At least three specimens, preferably from different batches, shall be made
for testing at each selected age.
Procedure:
Specimens stored in water shall be tested immediately on removal from the water and while they
are still in the wet condition. Surface water and grit shall be wiped off the specimens and any
projecting find removed specimens when received dry shall be kept in water for 24 hours before
they are taken for testing. The dimensions of the specimens to the nearest 0.2mm and their
weight shall be noted before testing.
Placing the specimen in the testing machine the bearing surface of the testing machine shall be
wiped clean and any loose sand or other material removed from the surface of the specimen,
which are to be in contact with the compression platens. In the case of cubes, the specimen shall
be placed in the machine in such a manner that the load shall be applied to opposite sides of the
cubes as cast, that is, not to the top and bottom. The axise of the specimen shall be carefully
aligned with the center of thrust of the spherically seated platen. No packing shall be used
between the faces of the test specimen and the steel platen of the testing machine. As the
spherically seated block is brought to bear on
the specimen the movable portion shall be rotated gently by hand so that uniform seating may be
obtained. The load shall be applied without shock and increased continuously at a rate of
approximately 140 kg/cm2/min.until the resistance of the specimen to the increasing load breaks
down and no grater load can be sustained. The maximum load applied to the specimen shall then
be recorded and the appearance of the concrete and any unusual features in the type of failure
shall be noted.
Calculation: The measured compressive strength of the specimen shall be calculated by dividing
the maximum load applied to the specimen during the test by the cross sectional area, calculated
from the mean dimensions of the section and shall be expressed to the nearest kg per cm2.
Average of three values shall be taken as the representative of the batch provided the individual
variation is not more than +/-15 percent of the average. Otherwise repeat tests shall be made.
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A correction factor according to the height / diameter ratio of specimen after capping shall be
obtained from the curve shown in Fig.1 of IS:516-1959. The product of this correction factor and
the measured compressive strength shall be known as the corrected compressive strength this
being the equivalent strength of a cylinder having a height/diameter ratio of two. The equivalent
cube strength of the concrete shall be determined by multiplying the corrected cylinder strength
by 5/4.
DETERMINATION OF FLEXURAL STRENGTH OF CONCRETE.
(IS: 516 – 1959)
Apparatus:
a) Standard moulds of size 15 X 15 X 70 cms for preparing the specimen.
b) Tamping bar.
c) Testing Machine.
Procedure:
Test specimens stored in water at a temperature of 250C to 30
0C for 48 hours before testing shall
be tested immediately on removal from the water, whilst they are still in a wet condition. The
dimensions of each specimen shall be noted before testing. No preparation of the surface is
required.
Placing the specimen in the testing machine: The bearing surfaces of the supporting and loading
rollers shall be wiped clean, and any loose sand or other material removed from the surfaces of
the specimen where they are to make contact with the rollers. The specimen shall then be placed
in the machine in such a manner that the load shall be applied to the upper most surface as cast in
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the mould, along two lines spaced 20 or 13.30 cms apart. The axis of the specimen shall be
carefully aligned with the axis of the loading device. No packing shall be used between the
bearing surface of the specimen and the rollers. The load shall be applied with shock and
increasing continuously at a rate such that the extreme fiber stress increases at approximately 7
kgs/cm2/mm for the 10 cm specimens, the load shall be increased until the specimen falls, and
the maximum load applied to the specimen during the test shall be recorded. The appearance of
the fractured faces of the concrete and any unusual features in the type of failure shall be noted.
Calculation:
The flexural strength of the specimen shall be expressed as the modules of rapture „ fb‟ which if
„a‟ equals the distance between the line of fracture and the nearer support measured on the
centerline of the tensile side of the specimen, in cm, shall be calculated to the nearest 0.5 kg/cm2
as follows.
fb = ( p X l ) / ( b X d2 )
When „a‟ is greater than 20.0 cm . for 15.0 cm specimen or greater than 13.30 cm for a 10.0 cm
specimen, or
fb = ( 3p X a ) / ( b X d2 )
When „a‟ is less than 20.0 cms. but greater than 17.0 cms for 15.00 cms specimen, or less than
13.30 cms but greater than 11.0 cms for a 10.0 cms specimen, where b = measured width in cms
of the specimen, d = measured depth in cms of the specimen at the point of failure, l = length in
cm. of the span on which the specimen was supported, and p = maximum load in kg. applied to
the specimen.
If „a‟ is less than 17.0 cm. for a 15 cm specimen or less than 11.0 cm for a 10.0 cm specimen, the
result of the test shall be discard
CHAPTER 9
GROUTING AND ROCK BOLTING
GROUTING
Grounds that the purpose of improving the poor soils with heavy loading conditions, them are
affected by natural disasters such as earthquakes or landslides, tunnels around or buildings main
floor of the features that help to bring more appropriate and sufficient conditions.
Ground Improvement Technique, the Affecting Selection of the Parameters
Ground /rock profiles and characteristic,
58
Groundwater of status and amount,
Favored level of improvement,
Improve the necessary space and depth,
Productions factors,
Environmental factors,
Cost,
Maintenance, durability, and operational requirements,
Types of Grouting Method
PERMEATION GROUTING:- This method describes the process of filling joints
or fractures in rock or pore spaces in soil with a grout without disturbing the formation.
COMPACTION GROUTING: Grout mix is specifically designed so as not to
permeate the soil voids or mix with the soil. Instead, it displaces the soil in to which it is
injected.
HYDRO FRACTURE GROUTING: Hydro fracture grouting is the deliberate
fracturing of the ground (soil or rock) using grout under pressure. Typically it is used to
compact and stiffen the ground or to access otherwise inaccessible voids.
JET GROUTING: The high-pressure water or grout is used to physically disrupt the
ground, in the process modifying it and thereby improving it.
ROCK GROUTING: Rock grouting is the filling by grout injection of fissures,
fractures or joints in a rock mass with grout without creating new or opening existing
fractures.
COMPENSATION GROUTING: Compensation grouting is the responsive use
of compaction, permeation or hydro fracture grouting as an intervention between an
existing structure and an engineering operation.
DEEP MIXING METHODS (DMM): Today accepted world-wide as a soil
improvement method this is performed to improve the strength, deformation properties
and permeability of the soil.
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APPLICATIONS:
1. Following to prevent excessive settlement
2. To increase allowable pressure of the soil both for new structures and/or additions to
existing structures.
3. Control of groundwater flow
4. Prevention of loose – Loose to medium sand densification under adjacent structures
(i.e. both for vertical and lateral movements) Due to adjacent excavations, pile
driving etc.
5. Ground movement control during tunneling operations.
6. Soil strengthening to reduce lateral support requirement.
7. Soil strengthening to increase lateral and vertical resistance of piles.
8. Stabilization of loose sands against liquefaction.
9. Foundation underpinning.
10. Slope stabilization.
11. Volume change control of expensive soils through pressure injection of lime slurry
(only for some expensive soils not at all)
AREAS OF USE:
Cement Grouts: For both impermeabilisation and strength increase.
Soil, Clay and Chemical Grouts: Impermeabilisation and compaction grouting.
Clay Grouts: Limited use (usually filling voids etc.)
Clay-Cement Grouts: Filling voids, mudjacking.
Although the two type of grouting used at BHEP with specification are
1) CONTACT GROUTING:-Such type of grouting is used for crown
in tunnel in one stage.
Specification: - 80lit/4bag, pressure:-4 bar
1m packer is used. 40mm inside
Dia. Of hole= 53mm (Boomer), 49mm dia. Of packer
1.5HP grouting pump( 6 line)
Considered parameter:- 1.Flow:- Magnetic flux flow meter is used(krohne
Marshall Batch Box 5500C). Capacity 0 to1000 liters but usually the flow is
below 100litre.
Pressure: - The pressure sensor is 0-40 Bar.
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The flow and pressure data is interpret through PLC (Programmable Logic Controller)
.The program work on window SCADA. It gives RS view.
GROUTING PUMP:-
1. Agitator: - It is a container in which we mix water and cement (grout). The size ofs
agitator is 600 liter.
2. Water and Cement Ratio:- The water and cement ratio is 0.4
3. In this 1.5 HP motor is used.
4. In grouting pump there is one pump which is distributing the grout in six lanes.
5. Density = 1.9
6. Flow rate = 11 avg.
2) CONSOLIDATION GROUTING:- It is used on overall circumference of tunnel.
The consolidation grouting is used after one month of contact grouting.
Specification:- 120lit/2bag,
5m packer is used.
Hole dia. 10m.
Grout use is 1:1.5
STAGES:-In consolidation grouting there is two stages.
S1 – 5m packer used
S2 – 5m packer used
The grout ratio is 1:1.5. In this 100kg of cement and 150 liter mix of water and Bentonite(124ltr
water and 27ltr bentonite). Bentonite is clay verities‟ which is 0.0016mm
In profile there are 12 holes. First we grouted the odd holes after that we will grout the even
holes.
PRESSURE:-
1. Pressure use on grouting is 12kg maximum.
2. Pressure use on packer is 16kg to 25kg .The pressure on packer should not be less than 16kg.
61
CONCLUSION:
Modern injection materials that ensure good permeation, short setting times and continuous work
progress have proven to give very dry tunnels at reasonable cost levels.
ROCK BOLT
Long anchor bolt for stablization rock excavations, which may be used in tunnels or rock
cuts.
Transfers load from unstable exterior, to the confined interior of rock mass.
Always installed in pattern, design (rock type excavation)
Work by knitting.
A zone of compression is induced in the region betweenrock bolt.
Provide effective reinforcement to rock mass when
i) Rock Bolt spacing (s) <3 average rock piller diameter.
ii) Rock bolt length (L) =2s.
DYWIDAG ROCK BOLTS
At the request of Jaiprakash Industries Ltd.,Delhi, DSI developed a specialized DYWIDAG
Rock Bolts System that was successfully used for the construction of several hydro caverns
in Northern India. The new system was developed in close cooperation between DSI
Germany and DSI UK. From initial consultations it was clear that the client required an
efficient fast track solution to facilite urgent power station construction. Within short time an
appropriate concept was developed by DSI UK and successfully tested and demonstrated in
site trials in Chamera.
The development of the specialized DYWIDAG Rock Bolting System is based on
DYWIDAG Pre-stressing Steel THREADBARS, utilizing mechanical expansion shell
anchorages. Fast setting bearing pads and head arrangements were design to suit the
application. The system proved its efficiency on site and met the clients need for rapid
installation and virtually immediate stressing using hydraulic jacks. Grouting after stressing
provided the required corrosion protection.
62
The ability to apply the design working load to DYWIDAG Rock Bolts so quickly enabled
cavern excavation to continue without delay.
During the period January to April 2001, DSI forwarded 12 shipping containers from
Germany to India with a total of 235 tons of the newly developed DYWIDAG Rock Bolting
to satisfy the customer urgent program. A total of 7,720 rock bolts in single section lengths
between 6 and 10 meters were supplied as follows:
2,390No. rock bolts 20 mm dia., grade 900/1100, THREADBARS - ultimate load
345 KN
5,330No. rock bolts 26.5 mm dia., grade 900/1030, THREADBARS - ultimate load
586 KN.
The DYWIDAG Rock Bolting has been very successful and continued use of the
system is expected.
The DYWI® Drill Hollow Bar is a fully threaded self-drilling anchorage system which can be
simultaneously drilled and grouted into loose or collapsing soils and brittle rock without the need
for a casing. Furthermore, the bar features a left-hand thread for standard rotary percussive
drilling. Manufactured from high grade steel tubing to EN 10083-1, DYWI® Drill Hollow Bar is
cold rolled to form standard rope thread or “T” thread profiles. The DYWI® Drill rolling process
refines the grain structure of the steel, increasing the yield strength and producing a robust drill
steel suitable for a range of drilling and grouting applications. The DYWI® Drill Hollow Bar
System includes a full range of drill bits, adaptor sleeves, couplers, nuts and bearing plates. In
addition, thanks to a wide range of DYWI® Drill injection adaptors and drill tooling, the hollow
bar can be used with DYWI® Drill Hollow Bar soil nails are idea l for loose or collapsing soils
as they can be installed without the need for a casing. The system is used for mixed fills, granular
material and loose overburden. The DYWI® Drill hollow bar system allows drilling and
grouting to be combined as a single operation and complies fully with EN 14490 (European
standard for soil nails).Soil nails are typically classified as lightly loaded (30-150 KN ), passive
installations. The fully bonded feature enables the loose wedge at the surface to be tied into the
deeper stable zone. Soil nails are normally regarded as low risk installations, with an element of
redundancy existing in the stabilized face. The design of soil nailed faces should incorporate a
diamond grid layout to ensure efficient distribution of the reinforcement. Suitable drainage must
be incorporated within the nailed face to prevent build up of water within the slope. This would
lead to uncontrolled loads at the facing at a later stage.
63
CHAPTER 10
ADIT AND TUNNEL CONSTRUCTION METHOD
Before starting construction of any underground structure we have to study tunneling method as
most of the structures are constructed inside a hill. For any construction we have to excavate. So
Adits are passage ways to main structures inside like HRT, TRT, Machine Hall, Transformer hall
extra. So in order to excavate the any structure inside the hill we have to reach there. The
passageway used is called Adit. It is constructed by the similar way as other underground
structures in this project. In this project we have many Adits leading to different structures inside
all the Adits are of different length the width is same but the width, height & length of other
underground structure varies.
The method of construction used is Drill Blast Method.
Drill and Blast
64
This tunneling method involves the use of explosives. Drilling rigs are used to bore blast holes
on the proposed tunnel surface to a designated depth for blasting. Explosives and timed
detonators are then placed in the blast holes. Once blasting is carried out, waste rocks and soils
are transported out of the Tunnel before further blasting. Most tunneling construction in rock
involves ground that is somewhere between two extreme conditions of hard rock and soft
ground. Hence adequate structural support measures are required when adopting this method for
tunneling.
Fig : Drill Blast cycle
DRILLING PATTERN DESIGN
The drilling pattern ensures the distribution of the explosive in the rock and desired blasting
result. Several factors must be taken into account when designing the drilling pattern: rock
drillability and blastability, the type of explosives, blast vibration restrictions and accuracy
requirements of the blasted wall etc. The basic drilling & blasting factors, and drilling pattern
design are discussed below. Since every mining and construction site has its own characteristics,
the given drilling patterns should be considered merely as guidelines.
DRIFTING AND TUNNELING
Many mines and excavation sites still plan their drilling patterns manually, but advanced
computer programs are available and widely used. Computer programs make it easier to modify
the patterns and fairly accurately predict the effects of changes in drilling, charging, loading
and production. Computer programs are based on the same design information used in
preparing patterns manually.
65
Basic design factors
The tunnel of drift face can be roughly divided into four sections (FIGURE 6.2.-1.).
Drilling pattern design in tunneling and drifting is based on the following factors:
- Tunnel dimensions
- Tunnel geometry
- Hole size
- Final quality requirements
- Geological and rock mechanical conditions
- Explosives availability and means of detonation
- Expected water leaks
- Vibration restrictions
66
Drilling equipment Depending on site conditions, all or some of the above factors are considered important enough
to determine the tunnel drilling pattern. Construction sites typically have several variations of
drilling patterns to take into account the changing conditions in each tunnel.
Drifting in mines is carried out with 5 to 10 drilling patterns for different tunnel sizes (production
drifters, haulage drifters, draw points, ramps etc.) The pattern is finalized at the drilling site.
Tunnel blasting differs from bench blasting in that tunnels have only one free surface available
when blasting starts. This restricts round length, and the volume of rock that can be blasted at
one time. Similarly, it means that specific drilling and charging increases as the tunnel face area
decreases. When designing a drilling pattern in tunneling, the main goal is to ensure the optimum
number of correctly placed and accurately drilled holes. This helps to ensure successful charging
and blasting, as well as produce accurate and smooth tunnel walls, roof and floor.
67
CHAPTER 11
CONCLUSION
We are very thankful to JAYPRAKASH ASSOCIATES LIMITED to give us the opportunity to
work in hydropower project.
In this project there are three turbine receiving 430 cumec from three penstock generating power
of450 MW. Although the project is having two stage each stage of 450 MW but stage 1 had
already been completed in 2005.the working of stage 2 was going on so our project is only on
stage 2.
However this project have the capability to generate 5 times more energy but due to shortage of
required discharge during winter the project is consistent to produce only 450MW in the entire
year
This project was completely echo friendly,uses renewable source and having high benefit to cost
ratio.
Due to weak rock of Precambrian age having Muree thrust lots of difficulties arises .thus the use
of the concept of rock stabilization considered to be very effective.
This project uses latest technique like Dywidey rock bolting, Shotcrete of steelfibre R/F,radial
gates with hydraulic hoists.
68
PLANS
69