This is the Internship report of the Neelum Jhelum Hydropower Plant.

1. Internship
Report
Neelum Jhelum Hydropower project
Submitted to: PD NJHEP
Submitted by:
Muhammad Khurram
2/28/2013

2. Table of contents
Acknowledgement
Introduction
o Rationale
o Background
o Salient features
Project Implementation
Practices learned
o Tunnel construction
 Drill and Blast Method
 Heading and bench method
 Grouting
Project Progress
Concluding Remarks

3. Acknowledgment
I would like to acknowledge the support of
Wiqar Ahmad and Geologist Majid at site C3.
Without their guidance I would not have learnt
so much.

4. Introduction:
Rationale:
To submit a report on the learning and knowledge gained at the one month internship, dated
6th June till 5th July, 2016, about the geological techniques involving tunnel construction,
Hydropower Generation systems and the management practices being carried out at the
Neelum Jhelum Hydropower project.
Background:
The Project is running through Neelum Jhelum Hydro-Power Company (NJHPC) WAPDA, headed
by a Board of Directors (BOD). The Chairman of the BOD is Chairman Wapda. Members of the
Board are Chairman Wapda, Member (Water) WAPDA, Member (Power) WAPDA Member
(Finance) WAPDA, CEO (NJHPC), CFO of the Company and EX-CEO of NJHPP, Chief Secretary
Azad Jammu & Kashmir, Additional Secretary Ministry of Water and Power, Additional
Secretary Economic Affair Division, Additional/Special Secretary Ministry of Finance. MD/Chief
Executive Officer, the representative of Board of Director, has his office at Islamabad whereas
Project Director (General Manager) has his office at Muzaffarabad (AJ&K).
Neelum Jhelum Hydroelectric Project is located in the vicinity Muzaffarabad (AJ&K). Itenvisages
the diversion of Neelum river water through a tunnel out -falling into Jhelum river. The intake
Neelum Jhelum is at Nauseri 41 Km East of Muzaffarabad. The Powerhouse will be constructed
at Chatter Kalas, 22 Km South of Muzaffarabad. After passing through the turbines the water
will be released into Jhelum River about 4 Km South of Chatter Kalas. Neelum Jhelum
Hydroelectric Project has installed capacity of 969 MW. The Project will produce 5.15 Billion
units of electricity annually.
A Composite Dam (Gravity + Rock fill) 160 m long and 60 m high will be constructed on Neelum
River at Nauseri. It is a Gated Diversion Dam. The dam will create a head pond of 10 million
cubic meters which will allow a peaking reservoir of 3.8 million cubic meters to meet daily
peaking of power for more than 4 hours. A six gate tunnel intake structure of 280 cumecs
capacity will be connected with three conventional flushing surface basins installed at their end
for taking sediment back into river.

5. Salient Features of the Project:
Overall Project Cost Rs. 274.882 Billion (as per 2nd revised PC-1)
Installed Capacity 969 MW Four Units @ 242.25 MW each
Dam Type Composite Dam (Gravity + Rock fill)
Height / Length 60/160 Meters
Annual Energy 5.150 Billion electricity Units Annually
Average Head 420 Meters
Design Discharge 280 Cumecs
Tunneling
Twin Tunnel
Single Tunnel
Tailrace Tunnel
Length 19.54 km each
Length 8.94 km
Length 3.54 km
Date of
Commencement
30-01-2008
Expected Completion
date
November 2018
Implementation Period About 10 years
The total length of head race tunnel is about 48 km. A 19.54 km stretch of the tunnel from the
Nauseri site will be constructed as a twin tunnel system each with cross sectional area ranging
from 52-58m2 . The remaining headrace tunnel down to the surge chamber will be a single
tunnel having cross sectional area 100m2 approximately. The tunnel portion to be excavated
with TBM will be shortcrete lined with a concrete invert while the drill and last portion of the
tunnel will have full face concrete lining. The tunnel crosses under the Jhelum River at EI. 602.0,
approximately 180m below Riverbed. The tunnel is accessed by 8 construction Adits for
removal of excavated spoil.
The Surge Chamber consist of 341m high riser shaft and 820m long surge tunnel, four steel
lined Penstock tunnels 118 m long and having 3.8 m internal diameter will also be constructed.
The underground power Station will have four units with a total capacity of 969 MW. The
Power Station will be connected with Gakhar Grid station through 500KV double circuit
transmission line.The Neelum Jhelum Hydroelectric Project is split into the following three main
geographic areas.

6. CHATTER KALAS AREA (ALSO KNOWN AS C3)
The headrace tunnel will feed four vertical-shafts Francis turbines with an installed capacity
of 969 MW housed in an underground powerhouse. The water is discharged back into the
Jhelum River near Zamainabad through a 3.5 km tailrace tunnel. Associated facilities include

7. a transformer hall, surge shafts, access tunnels, a 500 kv switch yard and housing facilities
for the operations and maintenance personnel.
Power house: The underground power Station will have four units with a total capacity
of 969 MW. The Power Station will be connected with Gakhar Grid station through
500KV double circuit transmission line.
Transformer Hall: The turbines inside powerhouse will transfer electricity to the
transformer hall located adjacent to power house where a step down transformer will
transfer the electricity to the switch yard through cable tunnels.
Bus bar tunnels: Tunnels connecting transformer hall and power house.
Penstock tunnels: Four steel lined Penstock tunnels 118 m long and having 3.8 m
internal diameter will also be constructed to transport water to the 4 turbines from
headrace tunnel.
Draft tubes: The water after impacting the turbines will be transported to tailrace
tunnel through draft tubes passing below the bus bar tunnels.
Switch yard: Cable tunnels will connect the transformer hall with the 500kv switch yard
located outside the tunnel.
Surge shaft: A 341m high and 820m long tunnel is being built to accommodate for the
backwater effect incase of power house shutdown for maintenance or malfunction.
Tailrace tunnel:The part of tunnel downstream of power house is named tail race
tunnel which is discharge water into the Jhelum river.
WAPDA colony: A residential colony will be built at the C3 site for the employees of
WAPDA that will work at Site C3 once it is operational.

8. PROJECT IMPLEMENTATION
CONSTRUCTION:
Construction Contract was awarded, on July 07, 2007 to M/s CGGC-CMEC consortium China for
implementation of the project at a cost of Rs. 90.90 billions including Rs. 46.499 Billions foreign
component.
Preparatory works including construction of Contractors Camps aggregate crushing & batching
plant, site access roads and site/test laboratory have been completed.
Board of Director NJHPC has approved the deployment of Tunnel Boring Machines (TBM) for
the Project on 23.11.2010. The contractor has arranged procurement of two TBMs from M/s
Herrenknecht Germany. The deployment of TBM will certainly help to put the project on
scheduled track and recover most part of delayed period envisaged for the commencement.
All the parts of TBM have been arrived at site and TBM assembly has substantially completed.
The Soft Opening/Inauguration of TBM was held on August 06, 2012 and the Honorable Prime
Minister of Pakistan graced the occasion by pressing the button.
1. Both the tunnel boring machines (TBMs) have been assembled and testing of each
segment completed. The operation of one TBM started on 28-01-2013.
2. CONSTRUCTION -ENGINEERING, DESIGN AND CONSTRUCTION SUPERVISION
3. Neelum Jhelum Consultants (NJC), a Joint Venture Comprising of five firms including
MWH International Inc., USA, NORPLAN A.S., NORWAY, National Engineering Services
Pakistan NESPAK (PVT.) Limited, Associated Consulting Engineers ACE (Pvt.) Limited,
National Development Consultants of Pakistan, have been selected for Engineer Design
and Supervision (EDS) as Project Consultants. Consultancy Agreement was signed on
May 15, 2008. Letter of Commencement was issued on May 16, 2008. Services have
been started since June 03, 2008.
Practices Learned:
Knowledge about the following civil engineering practices was gained.
Tunnel Construction:
Tunnel construction is the main civil engineering component of the project and special focus
and effort has been put into it to gain the required quality and specifications according to the
project plan.Following techniques are being used at the project

9. Drill and Blast method:
Drill and blast method is the main process and major portion of tunnel will be excavated with
this technique. It involves the following steps
Step 1 Drilling and Surveying
A jumbo is used to drill holes in the rock face. This one has three drilling arms and anoperator
tower. It is run by electric cable; a hose brings water to the drills. The drills arepneumatic (new-
mat-ic). That means that the drill bits both hammer and rotate. Broken bits ofrock are flushed
out by water. These drill holes are 2.4-3.6 metres long.
The diagram in the lower right of the screen shows the location of holes drilled on the rockface,
and the order in which they are drilled. The first sets are straight holes (parallel cut)located
around the edge of the face and in the middle. A second set (V-cut) is angled towardthe center.
These allow the rock to be blown away from the face into the drift (tunnel).
Step 2 Charging with Explosives
Holes drilled are next filled with explosives. This is done by miners standing on the groundand,
if the rock face is high, by using another jumbo with booms to lift the miner. Chargingmay be
done using cartridge explosives, also known as stick powder or dynamite. Thecartridges are
placed in the holes and pushed to the back using a wooden ramrod. Awaterproof detonator
cord, or fuse, hangs out of the end of each hole. The primer that startsthe explosion is at the
end of the fuse in the bottom of the hole.
Charging may also be done using bulk explosives. This granular material, commonlyammonium
nitrate fuel oil, is blown by air into the holes. Again the fuse with a primer at the farend hangs
from each hole.
Step 3 Blasting and Ventilation
The individual fuses are connected to subfuses (yellow box) then to a main fuse (red box) in
away that ensure the holes are blasted in a proper sequence, from the center outward, one
afterthe other. Although more than 100 explosions may be set off, one after the other, the
blastsequence is completed in several seconds.
After the blast rock dust and gases are sucked out via the main tunnel while fresh air is
delivered via a ventilation duct on the tunnel ceiling.

10. Step 4 Loading and Hauling
In a mine the broken rock is called muck and the process of loading and hauling is
calledmucking out. Here an electric shovel loads the muck into a hauler dump (HD). As it
worksaway, the muck is squirted with water, which is delivered by hose to the shovel to keep
thedust down. The HD is articulated in the middle, that is, it has a joint that allows the machine
tobend around tight corners. The driver sits in an armour-protected cabin. Depending on
thelayout of the mine, the HD will haul the muck to an ore pass, another dump truck, a tram, or
astockpile, all eventually ending up at a primary crusher.
In some locations mucking is done using a scoop tram, or LHD - short for load-haul-dump.
This machine, as the name implies, loads up with muck, hauls the muck and dumps the muck -
so there is no need for a separate shovel.
Both the HD and scoop tram run on either solid rubber or foam-filled rubber tires. They areused
because air-filled tires may explode under the extreme weight and heatof friction causedby the
loads.
Step 5 Scaling and Cleaning
Scaling refers to removing all the loose (loose rock) from the roof and walls of the drift.
Thereare three methods. 1. A hydraulic breaker mounted on a boom operates like a
jackhammer,dislodging fractured material. 2. A rotating cutting head mounted on a boom
revolves and sobrushes or chews loose material from the roof and walls. 3. Scaling uses a
wedge of steelmounted on the boom to drive into rock fractures and scrape off loosened
material.When the rock is highly fractured, miners refer to this as bad ground; it must be
sprayed withconcrete to prevent loose rock from continually sloughing off. The concrete is
sprayed from ahigh-pressure air hose that must be mounted on a boom if the walls and roof are
high.
Step 6 Rock Bolting
The final method for stabilizing rock faces is most commonly rock bolting. A jumbo is usedhere
to first drill holes into the rock. The holes vary from 2.4-6 metres long. Next a steel rodwith a
wedge threaded on the end is inserted in the hole. When it is in place, the rod is turnedso that
it pulls out against the wedge, forcing it into the walls of the hole. The outside end ofthe rod is
secured with a steel plate and large nut. Geologists and engineers at a minedetermine the
spacing and depth of rock bolts required for the conditions at their site.Under the poorest
ground conditions it may be necessary to put steel arches in place to holdup the walls and roof
of a tunnel. In other situations a steel mesh may be secured to the wallsand roof to prevent
other loose materials from falling on workers below.

11. Survey for Blast
(1hrs)Drilling for Blast
(3hrs)
Charging for Blast
(1hrs)
Blast (1/2hrs)
Ventilation (1/2
hrs)
Mucking (6 hrs)
Scaling (2hrs)
Geological
mapping (1/2 hrs)
Shotcrete 1st Layer
(2hrs)
Drilling for Rock
Bolts (2hrs)
Installation of
Rockbolts (1hrs)
Shotcrete 2nd
Layer (2hrs)
Survey for Blast (1hrs)
Drilling for Blast (3hrs)
Charging for Blast (1hrs)
Blast (1/2hrs)
Ventilation (1/2 hrs)
Mucking (6 hrs)
Scaling (2hrs)
Geological mapping (1/2 hrs)
Shotcrete 1st Layer (2hrs)
Drilling for Rock Bolts (2hrs)
Installation of Rockbolts (1hrs)
Shotcrete 2nd Layer (2hrs)

12. Heading and Bench Method:
This method is used where the strata is loose soil and cannot stand for long time and cannot
sustain blasting. In this technique, workers dig a smaller tunnel known as a heading. Once the
top heading has advanced some distance into the rock, workers begin excavating immediately
below the floor of the top heading; this is abench. One advantage of the top-heading-and-
bench method is that engineers can use the heading tunnel to gauge the stability of the rock
before moving forward with the project.
Notice that the diagram shows tunneling taking place from both sides. Tunnels through
mountains or underwater are usually worked from the two opposite ends, or faces, of the
passage. In long tunnels, vertical shafts may be dug at intervals to excavate from more than two
points. This is a very slow method.
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.

13. Grouting Material
The selection of grouting material should be based on the tightness and environmental
requirements, and the geological and hydrogeological properties of the rock mass. Grouting
materials for rock can be divided into:
• cementitious
• Chemical
• A mix of cementitious and chemical compounds
The materials used in the reported Finnish cases are mostly cementitious materials, normally
Rapid cement or microcements (Sievänen & Hagros, 2002). Chemical grouts were used in only a
few cases.
Grouting Design
Pre-investigation at the construction site is needed when planning grouting. Actually, more critical
tightness requirements exist, though more detailed investigations are needed to produce good,
predictable results. General fracture properties like spacing, length, or even aperture can be
evaluated quite simply (at least to a certain degree of accuracy). But, the fracture network
(boundary conditions) or fracture fillings are more complicated, and, in many cases, these play a
leading role in controlling the whole grouting process.
The main rule of thumb states that well-designed pre-grouting reduces the amount of inflow water
and the need for post-grouting. Furthermore, the delay time between the grouting and excavation
stages, as well as different grouting phases, must be enough for grout hardening.
Grouting Method
Grouting Procedure
Regardless of the number of exploratory borings or other preconstruction investigations,
information on the size and continuity of groutable natural openings in rock below the surface will
be relatively meager at the start of grouting operations and only slightly better after the grouting is
completed. The presence of groutable voids can be ascertained before grouting and verified by
grouting, but their sizes, shapes, and ramifications will be largely conjectural. In large measure, the
“art” of grouting consists of being able to satisfactorily treat these relatively unknown subsurface
conditions without direct observation. The discussions of grouting practices in this manual are

14. intended to guide the apprentice, but not to replace experience. All the procedures and methods
presented for grouting rock apply to portland-cement grouting; some of them apply equally well
togrouting with other materials.
Curtain Grouting.
Curtain grouting is the construction of a curtain or barrier of grout by drilling and grouting a linear
sequence of holes. Its purpose is to reduce permeability. The curtain may have any shape or
attitude. It may cross a valley as a vertical or an inclined seepage cutoff under a dam. It may be
circular around a shaft or other deep excavation or it may be nearly horizontal to form an umbrella
of grout over an underground installation. A grout curtain may be made up of a single row of holes,
or it may be composed of two or more parallel rows.
Contact Grouting.
Contact grouting is the grouting of voids between the walls of an underground excavation and its
constructed lining. These voids may result from excavation over break, concrete shrinkage, or a
misfit of lining to the wall of the excavation. The crown of a tunnel is a common locale for contact
grouting.

15. Project Progress:
The main progress of the project works is as under
Contract
Tunnels/Other
Works
Unit Total Works
Completed
Works Up to
January, 2013
Progress (%)
Lot C-3
ChattarKalas
Headrace Tunnel
(Single)
m 3,622 2,542 70 %
Tailrace Tunnel m 3,550 1,658 47 %
Access Tunnels
(A5,A6,A7)
m 5,479 4,992 91 %
Power House
(Excavation)
m3 148,463 95,033 64 %
Penstock (4 Nos.) m 472 472 100 %
Draft Tube tunnels
(4 Nos.73m each)
m 292 280 96 %
Bus Bar (4 Nos.
40m each)
m 160 160 100 %
Crane Beam U/S &
D/S
m 137 137 100 %
Transformer Hall
(Excavation)
m3 51,372 38,082 74 %
Total Headrace Tunnel (C1+C2+C3) m 48,692 15,382 32 %
Overall Physical Progress is 45.43 % (This is progress of tunnel excavation which is a critical
activity for project completion) while the overall Financial Progress is 21.64 % Up to the end of
January, 2013.

16. Concluding Remarks:
This Internship was really helpful in making me understand the working of engineering bodies
at field , a hand on experience of how things works at the site. I had the opportunity to see in
person the civil engineering techniques being applied in field which I was taught about in my
lectures. My perception of civil engineering techniques from what I learned from the books was
evolved into a better, professional knowledge of field. This internship which was basically to
learn about the Neelum Jhelum Hydroelectric Project and the different Engineering Techniques being
used at the project taught us
• How clients oversee the project progress.
• Working of Contractors and Subcontractors under the Client.
• Tunnel Excavation methods.
• Grouting and its procedure.
It was really inspiring to see the working together of different fields of engineering like Civil ,
mechanical and Geological Engineering to produce a marvel , to observe Different engineering
Companies working together as clients ,contractors etc to achieve a common goal. It
strengthened my belief that Geology helps humanity to move towards a better future. It was
interesting to observe that efficient management makes a Mammoth Project look achievable
and Feasible, saves time and resources, minimizes risks associated.