National University of Computer and Emerging Sciences
Department of Civil Engineering
“A Concise Guide To Educational Tour To
Neelum Jhelum Hydropower Project”
Prepared by: Engr.* Muhammad Hassan Khan Niazi
4th
- 7th February, 2014
*Still working on that. Keep calm only two years are left.
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Table of Contents
Trip Details ................................................................................................................................................... 2
Purpose ...................................................................................................................................................... 2
Arrangements ............................................................................................................................................ 2
Management Team and Important Contacts ......................................................................................... 2
Schedule .................................................................................................................................................... 3
Weather forecast ....................................................................................................................................... 3
Check List ................................................................................................................................................. 4
Route ......................................................................................................................................................... 4
Neelum Jhelum Hydropower Project (NJHPP) Details ................................................................................ 5
Location .................................................................................................................................................... 5
Project Overview ...................................................................................................................................... 5
Parties Involved ........................................................................................................................................ 6
Client ..................................................................................................................................................... 6
Contractor ............................................................................................................................................. 6
Consultants -Engineering, Design and Construction Supervision ........................................................ 6
Project Planning ........................................................................................................................................ 6
1. Nauseri Area (Also Known As C1) .................................................................................................. 6
2. Majhoi/Thota (Also Known As C2) .................................................................................................. 6
3. Chatter Kalas Area (Also Known As C3) ......................................................................................... 6
Project Components & Their Technical Details ....................................................................................... 7
Geology ..................................................................................................................................................... 7
Pivotal Decisions ...................................................................................................................................... 8
Single or Twin Tunnels ......................................................................................................................... 8
Shotcreted or Concrete-Lined Tunnels ................................................................................................. 8
Deep or Shallow Jhelum River Crossing .............................................................................................. 9
Excavation, Drilling and Blast Tunneling ............................................................................................... 10
Tunnel Boring Machines (TBM) ........................................................................................................ 10
Work Progress and Current Status .......................................................................................................... 11
Controversial Kishanganga project by India ........................................................................................... 12
Project Benefits ....................................................................................................................................... 12
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Trip Details
Purpose Educational Site visits provide an excellent glimpse of the near future to civil engineering students. It is a
way to see what they’ll be doing out in the field in a more practical way. The following was the reason
why this first site visit has been planned.
There are several reasons why the visit is specifically planned for Muzaffarabad.
1. A TBM (Tunnel Boring Machine) has been introduced first time ever in Pakistan;
2. A Dam is under construction in that area;
3. A cantilever bridge is under construction;
4. Geological Experience;
5. Hydraulics negotiations;
6. Structural features investigations;
7. Strength of Materials and construction materials used;
8. Ground and tunnel survey acknowledging;
9. Study of the topography of that area;
10. Rehabilitation construction for earthquake victims.
Arrangements Major outline of arrangements for Educational Site Tour to Muzaffarabad (Neelum Jhelum Hydropower
Project) are:
Transport facility has been provided by Lasani Tours
Accommodation and Meals are covered by Sangam Hotel (www.newsangamhotel.com).
Management Team and Important Contacts
Management teams have been formed to cater any issue during the tour. Management teams and
important contacts in case emergency include:
Management Head: Azaz Ghumman ( 0300 7774442 )
Organizing/Finance Team Heads: Asad Raja (0331 2253078) & Saad Ijaz (0322 4811114)
Research and Resource Team Head: Hassan Niazi ( 0324 4521015 )
Security Team Head: Qasid Ahmad (0333 6712688)
Sangam Hotel Management: Javed Jamal (Director-05822-444194-95)
Hospitals Nearby the hotel
o DHO : +92-(0)-5822-921951
o AIMS: +92-(0)-5822-921016
o Sheikh Khalifa Bin Zayed Al-Nahyan Hospital: +92-(0)-5822-920437
Team has worked hard to pull off a great learning experience for all the colleagues of our department. Do
remember all of them in your prayers.
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Schedule Tentative schedule for the tour is as follows:
4th
February 2014:
10 pm Departure from FAST-NUCES Lahore.
1st Day - 5
th February 2014:
10 am-3 pm Arrival at first Neelum Jhelum C3 site known as Chattar Class site.
Followed by Visit to Power House Site
Followed by Visit to Cantilever Bridge.
3:30 pm Arrival at Sangam Hotel
2nd
Day - 6th
February 2014:
9 am We leave for Neelum Jehlum C1 site Known as Nasuari Site.
11:30am Arrival at C1 site.
Visiting hours: 12 pm- 4 pm.
Here we will visit Diversion Tunnel, Dam Construction and Coffer Dam Construction.
6 pm Arrival Back to Hotel at.
3rd
Day - 7th
February 2014:
9 am Leave Hotel
Visit to Audit Tunnel Site, C2 site Majhoi Tunnel Site, TBM site.
12:30 pm At Leaving for Lahore.
10 pm Expected Arrival at FAST Lahore.
Weather forecast On the whole weather won’t be too harsh to you but showers of rain may affect your mood adversely and
make it seem like its cold but have faith in science, It won’t be too cold. Don’t forget to take a rain coat
along.
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Check List This is a general checklist for the items you would need during the trip:
Original N.I.C along with a copy
Warm clothes (sweaters, jeans, jacket, socks, gloves, etc)
Rain Coat
Some cash for your personal shopping in a wallet
Medicines if any of you are any permanent medication otherwise first aid box containing main
necessary medicines will be present in every bus.
Small hand towel
Notepad and pen for taking notes on site during briefings
Carry a bag that is handy and you feel free to carry it
Take light running shoes or trail running shoes (preferable) otherwise grab the one in which you
feel easy
Tooth brush.
Cell phone charger (Hands free is optional)
Camera
Especially for girls and some of our other fellows: Make up kits.
Route There are two proposed routes: via Motorway and via Grand Trunk road.
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Neelum Jhelum Hydropower Project (NJHPP)
Location Neelum Jhelum Hydropower Project (NJHPP) is located in the vicinity Muzaffarabad (AJ&K). It
envisages 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. NJHPP has installed capacity of
969 MW. The Project will produce 5.15 Billion units of electricity annually.
Location map of Neelum Jhelum Hydro Power Project indicating Dam Site, Tunnel Route and
Power House is given below:
Project Overview The Neelum-Jhelum project is some 100 km to the north-west of Islamabad close to Murree fault
line. It utilizes a gross head of about 420 m by diverting the Neelum River water from the village of
Nauseri to the lower limb of the Jhelum River through a 32.5 km long tunnel system. The optimized
maximum power station output is 969 MW, corresponding to a designed maximum discharge of 280
m3/s. The project yields an average annual energy generation of 5254 GW/h, and due to the adoption of
an underground layout and careful planning. The project has limited environmental impact.
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Parties Involved
Client
Water and Power Development Authority (WAPDA)
Contractor
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 Contractor's camps aggregate crushing &
batching plant, site access roads and site/test laboratory have been completed.
Consultants -Engineering, Design and Construction Supervision
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.
Project Planning The Neelum Jhelum Hydroelectric Project is split into the following three main geographic areas.
1. Nauseri Area (Also Known As C1)
A 60m high Composite (Gravity + Rock fill) diversion dam and sedimentation basin near Nauseri
is on the Neelum River. The dam has 3 No. Radial gates and 2 No. flap gates designed to pass floods of
1000 year recurrence period and also allow the reservoir to be drawn down for sediment flushing. The
sedimentation basins are designed to trap sediments that could erode the turbine blades at the powerhouse.
The intake works are designed to divert up to 280m3/s into the headrace tunnels.
2. Majhoi/Thota (Also Known As C2)
The headrace tunnel is 48 km long including twin tunnel and conveys the water from the intake
area at Nauseri to the Powerhouse area near Chatter Kalas. The tunnel crosses under high ground and also
across the Muzaffarabad fault zone. A 19.54 Km stretch of the tunnel from the Nauseri be constructed as
a twin tunnel system each with x-sectional area ranging from 52-58 m2 and the rest of the route, a single
tunnel of x-section area 100 m2 approx, has been proposed. The tunnel portion to be excavated with TBM
will be shortcrete lined with a concrete invert while the drill and blast portion of the tunnel will have full
face concrete lining. The tunnel crosses under the Jhelum River at 602 m asl, approximately 180m below
Riverbed.
3. 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 3.54 km tailrace tunnel. Associated facilities include a transformer hall, surge
shafts, access tunnels, a 500 kv switchyard and housing facilities for the operations and maintenance
personnel.
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Project Components & Their Technical Details A composite Dam (Gravity + Rock fill) 160m long and 60m 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 three
conventional flushing surface basins installed at their end for taking sediment back into river.
The total length of headrace tunnel is almost 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 blast portion of the tunnel will have full face concrete
lining. The tunnel crosses under the Jhelum River approximately 180m below Riverbed.
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.
Geology Rock was classified Q1 for strongest to Q5 for weakest. Q3 and Q4 classes are the most dominant
classes along the waterway, representing around 85 % while class Q1 rock masses are not expected to
occur. For each Q-class corresponding rock support resources (RS) were defined.
The surface cover of the proposed headrace tunnel is largely concealed by thin to thick layers of
Quaternary deposits. Rocks exposed at various outcrops over and around the proposed headrace tunnel
exclusively belong to Murree formation. The two geologic materials exposed in the project area the
quaternary deposits and bedrock, are briefly described below:
Quaternary Deposits: The Quaternary deposits contain upper Pleistocene to Recent alluvial, colluvial
and terrace deposits. These are tectonically less disturbed and generally form only a thin cover above the
headrace tunnel alignment. None of these materials are deep enough to reach tunnel vicinity.
Bedrock: The tunnel alignment passes through Murree formation which comprises alternate beds of
sandstone, siltstone, mudstone and shale.
Sandstone: Sandstone can be subdivided into SS1 and SS2. The SS1 sandstone is generally strong, well
cemented, and fine to medium grained. The sandstone is thinly to thickly bedded, at places massive and
blocky, moderately to closely jointed and at places fractured. In general, the thickness of sandstone
outcrop between Nauseri and Thotha ranges from 5 to 20m. The SS2 sandstone is usually reddish brown
and appears to be gradually changing to finer materials which include thin siltstone and mudstone beds.
Siltstone: Siltstone is grayish brown to reddish brown, sandy at places, strong to medium strong and
intermixed with mudstone and shale. In general, the thickness of siltstone between Nauseri and Thotha
ranges from 3 to 6 m while between Thotha and Agar Nullah it ranges from 0.3 to 2 m.
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Mudstone: Mudstone is reddish brown, weak to medium strong, and slightly to moderately weathered. In
general, the thickness of mudstone between Nauseri and Thotha ranges from 1.5 to 4 m. In downstream
parts of the tunnel the beds are slightly thinner.
Shale: Shale is dark to reddish maroon, weak sheared and fissile in nature. It occurs in thin beds at places.
In general, the thickness of shale is 0.5 to 1 m.
Pivotal Decisions
Single or Twin Tunnels
As a general rule, a single tunnel is normally chosen since both the excavation volume and the
loss of head due to friction increase with multiple tunnel system conveying the same flow. The advantage
of having more than one tunnel is the reduction in construction time and lesser geological risks from
smaller excavated cross-section.
The first part of the waterway represents the crossing of the Murree formations between Nauseri
intake and Jandarbain Valley. Due to topographical constraints, about 11 km of tunnels are to be
excavated between adit A2 in Jandarbain Valley and the adit AI at the Nauseri intake. The reduced
construction time with a twin tunnel configuration would be beneficial for this portion of the waterway.
For the remaining parts of waterway (approximately 21 km between upper Jandarbain (T2) and the outlet)
the topographical conditions facilitate establishment of construction adits and hence six (6) excavation
fronts. The average length of tunnel excavation fronts is slightly more than 3 km. From an economical
point of view, a single tunnel waterway was the right selection for this part.
The twin tunnel configuration for the T1-T2 portion reveals slightly higher total costs but it was
recommended for two main reasons:
The mountain formations between Nauseri and Jandarbain have high overburden and will yield
high rock stresses. The choice of two tunnels instead of one gives a reduced tunnel size which
represents a lower geological risk when crossing these formations.
The single tunnel has 2.5-3 years longer construction time.
It was noted that even after selection of a twin tunnel configuration, the T1 – T2 section still remains on
the critical path in the overall construction schedule.
For twin tunnels to progress faster than a single tunnel it was necessary to deploy two complete
sets of excavation and lining equipment. Alternatively provide cross-passages at about 200 m – 250 m
centers so that drilling and excavating plant could move quickly from one face to the other. At a later
stage of construction in a bid to accelerate works the tunnel boring machine (TBM) was deployed which
changed the Drill and Blast (D&B) requirements.
Shotcreted or Concrete-Lined Tunnels
The thickness of overburden above the tunnel in section T0-T2 is very large. The ground water
table would be located very high above the tunnel. The pore water pressure in the rock mass around the
tunnel can be expected to be higher than the water pressure in the tunnel itself. This means that a
significant hydraulic gradient towards the tunnel should be expected. The magnitude of this gradient
depends on the permeability conditions in the rock mass around the tunnel.
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The change in water pressure in the tunnel due to power peaking and reservoir level changes will
not be very abrupt. The pore pressure in the rock mass around the tunnel will adjust accordingly at a slow
or moderate rate. In the Detailed Engineering Design report 1997 the draw down rate was limited to 20 m
per hour, to safeguard the tunnel and its support structure against unacceptable external water pressure.
With the specified thickness and flexural and tensional strength of steel fibre reinforced shotcrete,
cracking and disintegration due to water pressure fluctuations and water flow was not to be expected. If
conditions indicating risk for erosion in clay/silt zones in the rock mass are encountered during tunnel
excavation, proper sealing and possibly pressure grouting should be considered in order to limit the
amount of water flow into/out from the tunnel. Experience about actual convergence and the
corresponding effect on the shotcrete, will form the basis for deciding on the best design and scheduling
of the shotcrete.
Deep or Shallow Jhelum River Crossing
The favorable and unfavorable points of both schemes were considered as follows;
Deep Crossing
Favorable Points
Same concrete liner as balance of tunnel with some additional reinforcement.
Lower Risk of hydro-jacking and better factor of safety.
No need of variation order.
Unfavorable Points
Increased tunnel length and higher mucking and haulage effort. Higher seepage during
construction under high hydrostatic pressure. Drainage will need more energy.
Greater head loss as compared to shallow alignment.
Not self draining. Deep-Well multistage pumping required. Extra manpower, time and
electricity required for dewatering.
Inspection and maintenance of the dip areas will be difficult task. Debris and sediment
deposit in lower part of dip.
During dewatering and inspection the power plant is out of operation resulting in loss of
income.
Powerhouse shutdown time during inspections is higher – 6 to 8 weeks.
Shallow Crossing
Favorable Points
Inspection and maintenance can be performed with other sections of the headrace tunnel.
Self draining tunnel. Drainage needs less energy.
Only one debris trap is needed before powerhouse.
Tunnel cost is less because of less excavation volume. Mucking and haulage is easy.
Powerhouse shutdown period during periodic inspections is lesser – 3 to 4 weeks.
Unfavorable Points
Major Concern for shallow crossing is hydro-jacking.
Requires reinforced concrete lining involving extra cost.
Requires additional 800 m steel lining.
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Liner cans do not fit into present access Adit A4.There is need to re-profile the adit or
make new access.
Risk of delay in steel procurement and cost escalation.
Excavation, Drilling and Blast Tunneling The excavation procedure should always be adapted to the local rock mass conditions. Excavated
rock is supported by rock bolts as a general practice. When traversing weakness zones or other areas of
heavily jointed or otherwise incompetent rock, immediate shotcreting, pressure grouting spilling or other
support measures may be required. In low quality rock mass short rounds and subdivision of rounds are
used. The objective is to obtain an opening with “stand-up time” long enough to allow the installation of
necessary support.
Smooth blasting was specified to reduce over breaks and control surface undulations. This
method is based on closely spaced contour holes, with reduced charges to be fired.
Tunnel Boring Machines (TBM)
A Tunnel Boring Machine (TBM) also known as a "mole", is a machine used to excavate tunnels
with a circular cross section through a variety of soil and rock strata. They can bore through anything
from hard rock to sand. Modern TBMs typically consist of the rotating cutting wheel, called a cutter head,
followed by a main bearing, a thrust system and trailing support mechanisms. The type of machine used
depends on the particular geology of the project, the amount of ground water present and other factors.
Main types of TBM are single shield TBM, double shield TBM and main beam TBM, among
them, double shield TBM and main beam TBM are commonly used on large size tunnels. The geologic
conditions at section T1-T2 indicate that the machine will have to pass through zones of large
convergence and high gush of waters. A main beam TBM with front shield and back side grippers was
therefore selected. The (selected) Herrenknecht TBM has been designed with special equipments and
tools to deal with extreme advance conditions. Success will depend on skilled management of operations
giving due time and importance to geologic monitoring and taking intelligent decisions. The net progress
rate of an 8 m machine was estimated to about 425 m per month.
The advantages of using a TBM include the following;
Continuous operation and higher advance rates.
Less rock damage and less support needs.
Greater worker safety and cleaner environment.
Disadvantages of a TBM are:
It has a fixed circular section
Longer mobilization time
Higher capital costs.
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 TBMs will certainly help to put the project on scheduled
track and recover most part of delayed period envisaged for the project completion.
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Work Progress and Current Status These are the details for the main progress of the project works up to the end of December, 2013.
Overall Financial Progress is 33.28 % and Overall Physical Progress is 53.50 % (This is a progress of
Headrace tunnel excavation which is a critical activity for project completion)
CONTRACT TUNNELS/OTHER WORKS UNIT TOTAL
WORKS
COMPLETED
WORKS
PROGRESS
(%)
Lot C-1
Nauseri
Access Tunnel (A1) m 385 385 100 %
Diversion Tunnel m 505 505 100 %
Headrace Tunnel (Single/Twin) m 7,367 7,055 95.76 %
Dam excavation (Spillway & Intake) m3 598,135 464,220 77.61%
Intake Structure RCC m3 44,070 23,525 53.38 %
Intake Structure CC m3 91,150 11,512 12.62 %
Spillway Concrete RCC m3 172,100 42,517 24.70 %
U/S Coffer Dam (RCC + Hard Fill) m3 26,434 26,434 100 %
Concrete Lining of HRT (Linear
meter) m 7,367 480 6.51 %
Lot C-2
Majhoi
Headrace Tunnel (Twin) by TBM m 23,000 3,085 13.41 %
Headrace Tunnel (Single/Twin) m 14,404 11,391 79.08 %
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Concrete Lining HRT (Linear meter) m 12,835 324 2.52 %
Access Tunnels A2,A3,A4, A4a etc m 8,676 8,595 99.06 %
Lot C-3
Chattar Kalas
Headrace Tunnel (Single) m 3,433 3,403 99.13 %
Tailrace Tunnel m 3,540 2,469 69.14 %
Access Tunnels (A5,A6,A7) m 5,479 5,228 95.42 %
Power House (Excavation) m3 148,463 146,710 98.82 %
Penstock/Draft Tube tunnels/Bus
Bar #4 each m 924 924 100 %
Transformer Hall (Excavation) m3 51,372 51,372 100 %
(C1+C2+C3) Total Headrace Tunnel m 48,204 24,934 51.72 %
Total Tunneling m 66,789 42,116 63.06 %
Controversial Kishanganga project by India Kishanganga hydroelectric project has the gross capacity of the reservoir of 18.80 million cubic
metres or 14,900 acre feet with dead storage of 8,755 acre feet. The water of river Kishanganga is to be
diverted through a 23-km-long tunnel to produce 330 megawatts of power. Water would join the Wullar
Lake after power generation and ultimately flow down through the Jhelum river to Muzaffarabad.
The construction of the Kishanganga project by India in Jammu and Kashmir will result in 14
percent decrease in the flow of water and will reduce energy generation by 13 percent or 700 million units
for Pakistan's NJHPP.
India was allowed to construct run-of-river hydroelectric plants and limited storage works on the
Indus, Jhelum, and Chenab rivers within the limits of design criteria provided in the relevant provisions of
the Indus Waters Treaty of 1960. But In February 2013, the International Court of Arbitration at The
Hague ruled in favour of India's position on the diversion of Kishanganga water, setting aside objections
by Pakistan.
Project Benefits Reduction of dependence on thermal power generation through reducing the import of fossil fuel
thereby saving in foreign exchange.
Employment opportunities during construction and later on during operation of the Project.
Improved standard of living.
Social-economic uplift of the area.
