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ON

Khan Khwar (72 MW) Hydropower Project

Submitted By: FAZAL ELAHI

Bs. Applied Geology University Of Azad Jammu & Kashmir

MUZAFFARABAD

Supervised By: Sr. Geologist Jehan Parviz

Submitted To:

Chief Engineer;

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ACKNOWLEDGEMENT

All praise to almighty Allah who is most beneficent and merciful. Who enabled me to read and write, then to holy prophet Muhammad (PBUH), who gave the light of Islam to mankind.

First of all I pay my deepest thank to Almighty Allah, who enabled me to complete my field work report successfully. I pay my deepest gratitude to my supervisor Mr. Jehan Pervez ; Senior Geologist Khan Khwar Hydropower Project. I am very much thankful to Jehan Pervez , who guided us very well and gave us a friendly company during our entire field Work.

I express my cordial thanks for the valuable and unforgettable discussion and supervision in preparation of this field report. It is due to hard work and keen interest of our leader who leaded us during the field report tour and delivered their valuable lectures by mean which I am able to write this field report and describe various rock and formation.

This flied work has made us memorable to understand the theoretical study. I once again pay my thanks to my teacher whom consider my self able for achieving my good goal and meet succession

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ABSTRACT

On 27th July 2010 we Start our internship.

According to the schedule of our field work we studied the geology of the Project area, its surrounding areas.

During our field we studied various rocks and geological structures and also studied how to classify Rock?

During this field work we visited the following sections · WEIR SITE. · Power House. · Tunnels. · And other surrounding places.

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INTRODUCTION:

Pakistan is a water rich country and is endowed with a hydel potential of

approximately 41722 MW most of which lies in the North West Frontier Province,

Northern Areas, Azad Jammu and Kashmir and Punjab. The following three High

Head Hydropower Projects utilizing the discharge of tributaries of the Indus River

near Besham in NWFP are a part of aforementioned Hydel Potential

Ø Khan Khwar (72 MW) Hydropower Project.

During three months summer break I decided to utilize my free time in availing

internship with some reputed firms or industries. There were several opportunities

for me like OGDC (Oil & gas Development Corporation) and PMDC ( Pakistan

minerals Development Corporation ). Being a Student Of Bs. Geology I preferred

to gain experience in above mentioned under construction three High Head

Hydropower Projects (HHP), Wapda, Besham. Because of my keen interest in

POWER GENERATION. During my internship I attended the erection work on

Francis and Pelton Turbines, Generators, Inlet Valves Different Type of gates,

Overhead cranes, Tower cranes, Cylindrical cranes and their auxiliaries and

accessories equipment.

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INVESTIGATION WORKS:

Between December 1994 and October 1995 , the following field works and

geological investigation have been carried out of khan khwar HHP covering all

alternative, studied during the Feasible phase::

1. Desk studies as to regional stratigraphy, tectonics and seismicity as well as

concerning hydro-geological, engineering geological and rock mechanical

relevant problems.

2. Geological field mapping of the whole project area with emphasis to hydro-

geological and engineering geological questions.

3. sinking of 21 core drillings with in total 906 running meters.

4. Carrying out 108 water pressure tests (LUGEON) with more then 160 packer

settings as well as six permeability tests . (LEFRANCE/MAAG)

5. Refraction seismic investigation as to thickness of overburden 21 profiles in

the DAM and Powerhouse areas, (3470 m )

6. Acceptance of representative rock samples for respective laboratories tests.

The results of all investigation work are compile in Appendices 5.1 to 5.2 to the

feasibility study. The following description and relevant annexes are given with

reference to the selected plant layout (powerhouse alternative "south" and weir

alternative "B" ) out of the studied alternative.

The geological investigations were carried out by consolidated engineering services

(PVT.) Ltd.,karachi(CES).

In the following , an interpretation of the engineering geological conditions is given,

using all available results of the above mentioned investigations carried out by CES

and subcontractors the results are discussed and annexed under the relevant item

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GEOLOGY OF THE PROJECT AREA

The project area is situated on the Besham nappe, which is dominated by the

gneisses of the Precambrian Besham Group, consisting of heterogeneous mixture of

granite and biotite-rich Ortho-gneisses together with a sequence of

metasedementary gneisses and schist’s, marbles and amphibolites. As most of the

contacts are sheared the original relationship between the ortho and para gneisses

are uncertain. the gneissic texture and fabrics with a quartz, feldspar, muscovite,

biotite, garnet and hornblendic amphibole mineralogy are the products of the pre

Himalaya high grade deformation and metamorphism , being associated with

granite and pegmatite intrusion.

Granite GNEISS:

It is light grey to dark grey, sometimes whitish, medium to coarse grained,

equigranular rock, Which comprises mainly quartz, feldspar, biotite , minor

amounts of muscovite, and magnetite. The texture varies from poorly to moderately

foliated , banding is often thin . its mineral Assemblage n broadly representative of

epidote-amphibolite facies metamorphism. Generally the rock is hard , slightly

weathered and sparely to moderately jointed. North-south trending oins have rough

,east-west trending joints have generally smooth surfaces . In the powerhouse and

the surge tank area , the rock is forming big-boulder-slopes due to steep eastward

dip(>5O’)

Leucco Granite:

this unit consists with the granite gneiss. The rock is hard, compact, massive,

relatively less deformed. And whitish gray to dark grey. course grain quartz veins

contain tourmaline crystals. contact zones of leucco granite with granite gneisses

are sheared.

Pegmatite:

Course grained pegmatite veins are intruding the leuco granites. These pegmatite

resembles more to the leuco granite. although they are course grained and contain

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no mafic minerals.

Amphibolites Bodies:

Mafic bodies subsequently metamorphosed to amphibolites occurs as discontinouse

dykes, sills, lenses and pods.

Graphitic Schists:

The rock is grey to black, the graphitic contents ranges to 4% to 10% with small

pyrite crystals. This unit occurs as lateral discontinuous layers and pods up to 30

meter thick. This schists are medium to fine grained. And soft to moderately hard.

Mica schists:

They are grayish black to early grey fine hard thinly t massive bedded and have a

schistose to weakly gneissic fabric.

Quartzites:

They are rusty brown to light grey hard, well compacted and medium bedded some

thick beds up to 20 m thick of quartzite are also present.

The karora group is a sequence of marine meta sediments resting unconformable on

the gneissic granite basement of BESHAM GROUP. The easternmost contact

between the karora group and Besham Group is marked by a distinctive angular

unconformity, comprises of pebble conglomerates. The rock of karora group is

exposed along the DAM axis, the reservoir area and in the tunnel inlet portal area.

Individual rock units of the Karora Group are as follow.

i. Graphitic Phyllites

ii. Psammitic mica schist/mica schist.

iii. Carbonates.

iv. Quartzite.

v. Quaternary Deposits.

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72 MW KHAN KHWAR HYDROPOWER PROJECT

The Khan Khwar Hydropower Project is located on the river Khan Khwar, a right

bank tributary of the river Indus in the Shangla district of NWFP at a distance of

about 262 Km from Islamabad and 270 Km from Peshawar. The maximum power

output of this hydropower plant will be 72 MW, corresponding to a turbine design

discharge of 35 m3/s at a mean gross head of 257 m. The Khan Khwar Hydropower

Project will produce an annual energy of 306 GWh out of which approximately 105

GWh/annum will be available during a 4 hour/day period of Peaking operation.

OBJECTIVES

1 The main objective of the program is to provide adequate opportunities for

generation transmission & distribution of 72 MW electrical energy generated

from Khan Khwar Hydropower Project to cope with the requirements for

industrial & agricultural development of the country.

2 To reduce load shedding during peak hours in the country by generating 72

MW Power output corresponding to a maximum design discharge of 35 m3/s

at a gross head of 257m from a buried penstock arrangement to

compensate/reduce load shedding during the peak hours.

3 To achieve cheap annual energy of 306 GWh out of which 105 GWh will be

available during 4 hours per day peak period.

4 To implement several programs for improvement of health, education &

infrastructure facilities and other programs for alternate sources of income

and employment opportunities to the local inhabitants.

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MAIN COMPONENTS OF THE PROJECT: -

There are Three Main components of the Project

(a). INTAKE OR WEIR SITE

The weir / dam is build at the intake structure across Khan Khwar for the collection

& storage of water from the catchment area,

Ø To regulate the water flow through the tunnel for the generation of power at

the power stations.

Ø To release the extra water through the spillway gates in the downstream

Khwar channel.

Ø To release the water through outlet gates for the flushing of sand and trash

from the reservoir.

(b). TUNNEL

The water from the intake reservoir flows through 5125 meter long tunnel for

operation of the Generating Units at Khan Khwar Power Station. Different portions

of the tunnel are: -

I. Head Race Tunnel (HRT): - This portion of tunnel lies between weir &

pressure shaft and is 4530 meter long, and 3.85 meter internal dia of

concrete lining.

II. Pressure Shaft: - It is concrete lining vertical shaft between HRT &

Pressure Tunnel. It has 183 meter length and 3.25 meter internal diameter.

III. Pressure Tunnel: - It is steel lining tunnel between pressure shaft and

spiral case of 425 meter length, 3.25 meter internal dia upto bifurcation.

(c). POWER HOUSE

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The total capacity of the power station is 72 MW comprising two main generating

units each of 34 MW and one auxiliary unit of 4 MW capacity. The water flowing

from the penstock enters into the turbine spiral case through the inlet valve

operating the runner / turbine at a speed of 500 rpm. As the generator is coupled to

the turbine through the intermediate shaft thus running at the same speed producing

34 MW power at terminal voltage of 11 KV. The water after operating the turbine

flows to the tail race into the river Indus.

(d). SWITCHYARD: -

The 11 KV terminal voltage of Generating Units is stepped up to 132 KV at

switchyard & transmitted to Allai Khwar Switchyard through 132 KV transmission

line where it is further stepped up to 220 KV for onward transmission to the

national grid.

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PROJECT DIGEST

1 Name of Project: Khan Khwar Hydropower

2. Location The Project is located in Distt:

Shangla

3. Contractors (a) CWH-HE JV for C&HS work

(b) DEC for E&M Works

4. Consultants High-Head Hydropower Consultants

5. Sponsoring Govt. of Pakistan through Ministry of

Water & Power

6. Execution WAPDA

7. Installed rated capacity 72 MW

8. AV. Annual Energy Output 306 GWH

9. No. & Type of Unit 2 Power Units of Francis Type

1 Auxiliary Unit of Pelton Type

10. Foreign exchange component Rs.2644.098 million (including cost

of transmission line)

11. Local Component Rs.2718.604 million (including cost

of transmission line)

12. Contracts

(I) KC-01 (LOT C&HS)

i. Contract Price Rs.1816.898 million

ii. Date of issuance of Construction

order

Jan 12, 2005

iii. Scheduled date of completion Feb-2010

(II) KE-04 (E&M)

i. Contract Price Rs.732.445 million

ii. Date of issuance of Construction

order

Jan 12, 2005

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iii. Scheduled date of completion Feb-2010

KHAN KHWAR HHP MAIN FEATURES WEIR SITE

1. Reservoir

Total Storage Capacity 1.05 million m3

Live Storage Capacity 0.40 million m3

Length 1.6 Km

2. Weir Structure Concrete Gravity Dam

Weir Height 30 m

Crest Length 116 m

Crest Elevation 829 masl

3. Headrace Tunnel

Type Pressure Tunnel

(Circular)

Length 4535 m

Size 3.85 m (Int: dia)

Discharge Capacity 35 m3/Sec

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MAIN FEATURES

Powerhouse

4. Powerhouse Shaft

Type Internal Type

Shaft Size 30.6 x 25.78 x 27.7 m

Machine Hall 25 x 30.6 x 16 m

Machine Hall Elevation 586.00 floor

601.70 top

5. Pressure Shaft

Shaft Size 3.25 m dia

Length of Shaft 190 m

6. Pressure Tunnel

Length 407 m

Size 3.25 m (Int.dia)

7. Surge Shaft 31 m

8. Upper Chamber 85 m

9. Lower Chamber 65 m

10. Tailrace Tunnel 58 m

11. Head

Max. operation level 825 masl

Min. operation level 818 masl

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Max. Gross level 257 m

Min. Gross level 247 m

MAIN FEATURES

Electro Mechanical

12. Hydro Mechanical Equipment

Francis Turbines 2 No.

Pelton Turbine 1 No.

Speed 500 rpm

Discharge 35 m3/Sec

Turbine axis Elevation 566 m

13. Electrical Equipment

Main Generators 2 No (34 MW)

Auxiliary Generator 1 No (4 MW

Speed 500 rpm

Output 34 MW (each)

14. Energy Output 72 MW

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ROCK CLASSIFICATION

ROCK QUALITY DESIGNATION (RQD)

A very poor 0 -25

B. Poor 25 -50

C. Fair 50 -75

D. Good 75 -90

E. Excellent 90 -100

JOINT SET NUMBER (JN)

A . Massive, none or few joints……………………………….……. 0.5 -1.0

B. One joint set……………………………………………………….. 2

C. One joint set plus random………………………………………… 3

D. Two joint sets…………………………………………………….. 4

E. Two joint set plus random………………..………………………...6

F. Three joint set plus random ………………………………………12

G. Four or more joint sets plus random, heavily jointed,” sugar cube” etc ……...15

H. Crushed rock earth like………..…………………………………..20

JOINT ROUGHNESS NUMBER (JR)

A. Discontinuous joints……………………………………………,..4

B. Rough or irregular, undulating…….……………………………,.3

C. Smooth undulating random……….……………………………..,2

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D. Slickenside, undulating…………………………………………1.5

E. Rough or irregular, planar…………………………….…………1.5

F. Smooth planar………………………………………………….1.0

G. Slickenside, planar…………………………………………….0.5

JOINT ALTERATION NUMBER (JA)

A. Tightly healed, hard, non softening ………………………….0.75

B. Unaltered joint walls, surface staining only…………………….1.0

C. Slightly altered joint walls, No softening mineral coatings……..2.0

D. Sility or sandy-clay coatings s mall clay fraction……………….3.0

E. Softening or low friction clay mineral coatings………………..,.4.0

(b) Rock wall contact before 180mm shear

H. Sandy particles, clay free disintegrated rocks……………….…4.0

J. Strongly over consolidated no softening clay mineral…………..6.0

K. Medium or low consolidation, softening,……………………….8.0

L. Swelling-clay fillings .…………………………………………8-12

(c) No rock will contact when sheared

M. Zones or bands of disintegrated or crushed rock………………6-8

N. Zones or bands of silty or sandy clay, small clay friction……….5.0

O. Thick, continuous zones or bands of clay…………………….13-20

JOINT WATER REDUCTION FACTOR (JW)

A. Dry excavations or minor inflow, i.e,<5mm locally…………………1.0

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B. Medium inflow or pressure, occasional outwash of joint fillings…..0.66

C. Large inflow or high pressure……………………………………….0.5

D. Exceptionally high inflow or water pressure at blasting,

Decaying with time………………………………………………..0.2-0.1

E. Exceptionally high inflow or water pressure Containing without noticeable decay

……………………………………………….………………………..0.1-0.05

STRESS REDUCTION FACTOR (SRF)

(a) weakness zones intersecting excavation,

Which may cause loosening of rock mass?

When tunnel is excavated

A. Multiples occurrences of weakness zones containing clay

Or chemically disintegrated rock, very loose surrounding rock………..10

B. Single occurrences of weakness zones containing clay

Or chemically disintegrated rock(depth of excavation >50m)………5

C. Multiples occurrences of weakness zones containing clay

Or chemically disintegrated rock (depth of excavation <50m)…….2.5

D. Multiple shear zones in competent rock……………….…………7.5

E. Single shear zones in competent rock(depth of excavation >50m)…………5.0

F. Single shear zones in competent rock(depth of excavation <50)…………2.5

G. Loose open joints, heavily jointed………………………………………..5.0

(b) Competent rock ,rock stress problem

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L. low stress near surface…………………………………….>200

P. medium stress……………………………………………….200-10

M. high stress……………………………………………………10.5

N. Mild rock burst(massive rock)……………………………...5-2.5

O. Heavy rock burst(massive rock)…………………………..…<2.5

(C) Squeezing rock plastic flow of incompetent rock under the influence of high

rock pressure

Mild squeezing rock pressure………………………………5-10

Heavy squeezing rock pressure……………………………10-20

FORMULA OF ROCK CLASSIFICATION:-

RQD/IN X JR/JA X JW/SRF = Q

General Diagram.

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CONTENTS

S/no Name Page 1. Introduction. 2. KhanKhwar Hydro Power Project. 3. Objectives 4. Main components of the project. 5. Project Digest. 6. Khan Khwar HHP main Features

Weir SITE.

7. Main features Power House. 8. Main features ELECTRO

MECHANICAL.

9. Investigation Works. 10. Geology of project Area 11. Rock classification. 12. General Diagram.