Indian National Committee on Large Dams. Design and Construction Features of Selected Dams in India

TABLE TV.E

Compressive

strength of air-entrained concrete.

(Laboratory

series-Source

B

cement)

Max. size of Aggregate-lt

in.

Test specimen-6 in.

x

12

in.

cylinder

Water-310-320 pcy

Slump-4

inch.,

Air

4

percent

Cement,

Pcy

W/C

by wt.

400

0.77

450

0.69

500

0.62

560

0.57

4s0

0.69

500

0.62

600

400

0.53

0.77

s60

600

0.57 0.53

Season

Age

days

Strength,

psi

Strength,

percent

1957-58

l9s8-59

1959-60

1960-61

t96l-62

600

I ll0

1620

600

I I50

r950

2650

3150

700

1250

2150

24r2

2700

770

l5l0

2230

750

1700

2750

3250

3650

950

1650

2700

2689

3350

r030

1970

2860

950

2200

3430

3800

4150

1220

2r00

3200

3550

1950

3000

3400

r300

2340

3360

1325

2800

4100

4550

4750

1600

2700

3800

4060

1600

2700

3790

1650

3150

4500

5100

5

r50

19s0

3200

4250

4713

s4

100

r46

52

100

170

250

274

56

r00

r70

193

216

5l

100

148

44

100

r61

191

2t4

58

100

163

r63

203

69

r00

il9

60

100

r45

43

100

,156

173

188

58

r00

r52

r69

7

700

28

1250

90

1850

7

rcO4

t2l4

r72l

28 1550 2100

2500

90

1900 2s30

2980

7

28

90

970

1900

2700

1250

2550

3400

I 700

3200

4100

2000

56

52

3540

100 t00

4400 148

142

2218

65

58

3620 100 100

3960

122

r20

53

s6

100

128

124

65

6l

t00 100

It3 109

47

r00

r33

1

28

90

r80

36s

-

28

90

r80

365

56

100

143

47

r00

146

r62

I70

60

100

140

r5l

60

r00

140

52

100

143

162

163

6t

100

133

r58

1

in.

:

2.51cm; I

pcy

:

0.59kg/cu

m

;

I

p.s.i.

:

70.31

gm/sq

cm-

4.9

Strength Data

: Job

Matrix Concrete

Working

under a specified

schedule of sampling

and testing, the

field

laboratory

staff

fabricate

test

specimens

15

cm

X 30

cm

(6

in.

x l2in.)

cylinders

for

testing at different

ages

up to

I

year.

The

strength

data is

compiled

and

statistically

analysed

to evaluate

the

same as

given

under

ACI-2146. The

strength

data

obtained for the

270

to

300 kg/cu

m

(450

and 500

pcy)

concrete

is

given

in Tables

IV.9

to

[V.12

which

covers

both the

age

:

strength

relation

and statistical

evaluation.

The

cement

used in

the

batching

plant

being

an

indefinite

combination

from both

sources

A

and

B,

it

will

not

be.

possible

to separate

the

strength

data

on

this basis.

However,

it

should

be noted

that

the-

strength

obtained

is

in

fair

agreement

with

the average

strengths

obtainable

from a mixture

of these

two

cements. The

average

strengths

obtained

for

mix

with

similar

cement content

fluctuates

from

season

to,

sea-

son, as

expected from

the

laboratory series,

at early

ages

but

remains

sensibly

the same at

one

year

(Com-

pare

Tables

IV.7 and

IV.8 of laboratory

series).

The

increase

in

strength with

age

seasonwise

is

plotted in

r37

TABLE

rv.g

Com

pressiv.

r

"."u,1""0{

il":ix

ron

cre

te

TABLE

IV.TT

Compressive

streneth

of

fi::T;*Tcrete

of

Koyna

Dam

Max.

size

of

Aggregate

-

l*

in.

Slump-3in.*tin

Test

specimen-6

in.

x

12

in.

Cylinder

Entrain

ed

air_4*.lo/o

of

Koyna

Dam

Max.

size

of

Aggregate

-

tt in.

Test

specimen-6

in. x

12

in.

Cylinder

Cement-50O

pcy

Slump-3in.

*1in.

Enrrained

air

-

4*l%

Season

1959-60.

Cement

content-45O

pcy

Season

1960:61.

Age

(days)

Particulars

Total

No.

of

tests

64

tg9

160

33

4l

Compressive

strength

p.s.i.

B9Z

tg38

2g0t

3ZO7

31768

Stlejnsth

percent,

28

days

49

100

lS3

tl|

z}s

Standard

devia-

tion,

p.s.i.

t4g

Z9S

347

365

506

Coefficient

of

variation,

o/s

L6.6

16.6

lz.4

Ll.4

13.3

Remarkg

regarding

quantity

of

con-

crete

represented

1.6

M

cu

ft

of

matrix

concrete.

I

in.

:

2.54

cm

I

cu

ft

:

0.02932

cu m

I

pcy:9.59

kg/cu

m

TABLE

IV.TO

Cernent

450

Pcy

-

Season

1959-60.

Particulars

Age

(days)

365

Particulars

Age

(days)

Total

No;

of

rests

263

644

386

ti5

gj

Compressive

srrength

p.s.i

726

1584

27gS

3Z3t

33S8

Strength

percent,

28

day

46

100

t76

204

Zt4

Standard

devia-

tion,

p.s.i.

148

309

42g

436

420

Coefficient

of

varia-

tion,

f

20.4

t9.5

15.4

13.5

12.4

Remarks

regarding

quantity

of

con-

crete

reprcsented

6.6

M

cu

ft

of

matrix

concrete

I

cu

ft

:0.2932cu

m

I

pcy

-

0.59

kg/cu

m

I

p.s.i.

:

70.31

gm/sq

cm

TABLE

IV.Iz

Cement

contenr

450

pcy

-

Season

lg6t_62.

Parriculars

Age

(days)

Total

No.

of

tests

139

5tg

4gS

gt

56

.Compressive

srrengrh,

p.s.i.

946

t70Z

2779

3lZ2

3400

Strength percent.

28

days

jO

t00

163

Ig4

2OO.

Standard

devia-

tion, p.s.i.

225

-

g62

457

390

$g

Coefficient

of

variation,

ts 26.6

Zl.Z

16.5

lZ,5

l1..g

Remarks

regarding

quantity

of

con-

90

28

r80

365

180

90

28

365

180

ill

48t

188

90

28

90

r80

36s

total

No.

of

tests

Compressive

strength,

p.s.i.

Strength percent.

28

days

Standard

deviation

p.s.i.

Coefficient

of

variation,

f

Rergarks

regarding

qDantity

of con-

crete

represented

lo0

16s

195

2s9

149

320

16.6

6.3

1t.4

475

82

7t4

1436

2364

2800

3343

233

474

50

r23

17.2

t4.2

5.2

M.

cu ft

of

matrix

concrete

crete

represented

4.75

IrL

cu

ft

of

matrix

concrete

I

p.s.i.

:

70.31

gm/sq

cm

I

cu

ft

:O.2932

cu

m;

I

p.s.i.

:

70.31 gm/sq

cm

r38

I

Pcy:Q.59

kg/

cu

rn

I

cu

ft

:

O.2832cu

rD

i

I

pcy

:

0.59

kg/cu

m

t\

o

j

eoo

N

t-

o

tl

o

E

o

C

t

o

- loo

z

a

o

ct

€

o

(.,

Age

1

do.ys

FTGURE

4.2

: Age

strength

relation

for

Koyna

Dam

matrix

concrete.

Figures

4.2

and 4.3, the

average

rise for

270 to 300

kg/

gu

m

(!!Q

a-nd

500

pcy)

conciete

as

pompared

to tft

base

of 28

days

strenglh,

is

as

follows

:

4.10

Strength

of

Rubble

Concrete

4.11

Density

of

Rubble

Concrete

Density

increased

with

increased

quantity

of rubble

sunk.

on

the

ciam

this

percentage

varied

for

34 to

3g

percelt.

Table

IV.l4

indicates

a

density

of

2640

kgl

cu

m

(165

lb/cu

fr)

though

it

could

Ue

slightty

-or..

7

days

28

days

90 days

I80

days

365

days

450

pcy

500

pcv

(270

kg/cu

m)

(300

kgitti m)

49

100

166

153

195

t7s

222

205

A

significant

feature of

the

Koyna

concrete

has

been

the

high

rate

of

gain

in

srrength

with

age

;

rhis

fact

is better

appreciated

from

Table IV.13 which

includes

the

gain

recorded

at

other dams.

The

slower

rate

of

gain

in

the early age

and the

faster

rate at

later

ages

is

more

attributable

to

the relatively

lower C3S

and

higher

C2S

contents

of

the

cement.

The

statistical

analysis

of

the

strength

reveals

that

the

standard

deviation

increases

with

age

whereas the

coefficient ofl

variation

drops. There

has

been

sufficient

controversy

over

the

point

whether

the

standard

r.o

t959-

60

aso ncv

Jx

te6o-

6l

(o.

t96t-

62

5oo

PCY'

rl

p59-6O

Hraf,.-+i+|.

139

I

TABLE

IV.T3

comparison

of

gain

in

strength_

in

maq

concrete

of

difrerent

projects

(Datacoilectedfromaifeienis-oir.lu'r)]'...

sl.

No.

Project

Type

of

cement

Mass

concrete

cement

content

pcy

28-day

strength

p.s.i.

I

year

strength

p.s.i.

o/o

of

28-day

strength

p.s.t.

1.

2.

3.

4.

5.

6.

7.

8.

9.

I0.

It.

12.

13.

r4.

I5.

16.

t7.

I8.

Norris

Shasta

Friant

Hungry

Horse

Canyon

Ferry

Denver-Ros-22

Sariyar (Turky)

Detroit

Boone

Dam

Fontana

Hartwell

Sutton

Pine

flat

Hirakud

Bhakra

Na-earjunasagar

(l

:

by rvt.

l0%

surkhi)

Koyna

x*

Type

II

Type

IV

Type

IV

e

II

p.C.

Type

II

p.C.

-do-

Type

II

-do-

Type

IV

Type

II

P.C.

Type

II

Type

II

P.C.

Type

II

P.C.

Type

II

3.91

338

376

282

235

282

235

?35

264

300

320

338

))7

24s

23s

300-380

260

292

4404

3200

2800

2080

2610

3270

1360

I

300

320

2282

2810

3870

3470

990

2030

r200

2100-3200

2200

2775

1570

6876

5870

5990

5270

4630

4240

3600

2560

2520

3292

4060

4730

4990

2400

3910

1

850

3200

4587

3370

r56

183

2t4

253

177

r29

194

197

307

144

145

140

144

242

r92

143

145-170

145

r65

220

*

**

P.C.:Pezzolan

Cement.

With

450

pcy

matrix

concrete.

I

p,s.i.

:

70.31

_em/k_e

cm.

TABLE

TV.14

Density

and

compressive

strength

of

rubbte

concrete

-

six

in.

dia.

cores.

Monolith

No..

Elevation

(rt)

Distance

from

axis

(ft)

Total

length

of

core

in

(rt)

Density

Pcf

Average

strength

p.s.i

correc-

ted

to

HID:2

Computed

one year

strength,

p.s.l.

Elasticity

M.

p.s.i.

A-se

H/D

of

days

core

48

l9

44

25

50

i5

33

I

24

2

2010

205r

205 l

206r

2061

2r45

2145

12

t3

r0

1

ilJ

20

22

168.4

r65.5

r

60.6

630

320

300

2.26

2.30

2.00

2.0

1.7

2.7

3.0

2565

3420

2332

3682

3625

3455

3220

4.8

)7

2.1

).)

165.1

t67.4

220

,220

168.8

240

2700

3320

2:00

3120

3072

3031

**

2930

**

)

15

140

p.s.i.

:

'10.31

gm/sq

cm

I

in.

:

2.54

cm; I

ft

-

0.3048

m.

I

6

U'

rt

€

o

c

o

UI

@

.:

o

L

o

E

o

u

'6

CL

c

€

E

a

(t

.E

o

lrl

Age,

doYs

FIGLJRE 4.3

:

Elasticity

and

strength

versus

age relation

for

Koyna Dam

matrix

concrete.

4.12

Bleeding

of

Concrete

With

the

use

of

manufactured

sand

and

manufac-

tured aggregate

in

the concrete with

7.5

cm

(3

in.) slump

it

is natural

to anticipate

the

problem

of

'Bleeding'

and its

collection

below

the

underside of rubble

in

rubble

concrete.

An

idea

of the bleeding

in the

manufactured

aggregate manufactured

sand

matrix

concrete

can be

had

from

the

following

data

collected

in

the

1959-60

season

at

the

field

control

laboratory.

The

mix

had

270 kg/ cu

m

(450

pcy)

cement

content

and

186

kg/ cu

m

(310

pcy)

water.

Bleeding

o/o

total water

At one hour

At the

end of

test

Invariably

bleeding

ended

in

120-150

minutes.

Inspite

of

using

manufactured

sand

it

can

be said

that

the

rate

of

bleeding

is low

probably

because

of the

presence

of 6-7

percent

of

200

fraction

in

the

same

and

of

entrained

air, besides the cement having

a

fineness

generally

over

3000

sq cmigm

(Blaine).

4.13

Elasticity

The

data regarding

the modulus

of

elasticity

was

essentially

required

for

the interpretation of data

collected from

the instrumentation programme. Hence

several

job

test specimens

15

cmx 30

cm

(6

in.

x

12

in.)

dia.

had

to be tested

with

the

use

of

a compressotneter

and the data collected

is

furnished in

Table IV.

15

and

plotted

in Figure

4.3.

It has not

been

possible

to directly

measure

the

elasticity

of the

0.9

m

(3

f0

dia.

rubble

concrete

cylinders

though

some

rough

idea

could

be

had

from

the 15 cm

(6

in.)

dia.

cores

tested

and

included

in

Table

IV.14.

Average

bleeding

for

23 tests

Range of

bleeding in

23

tests

1.38

o.6L

-

2.31

1.80

0.67-3.00

141

SOOPCY

,,

5T

esbTcT----l-

--

5er

Strength

ptostic-ity

ST:52T

elc.

denofre

No.

of lests

I

os

shorvn

in

toble

XVI

-e.--

V.r*P417

TABLE

IV.15

Modulus

of elasticity

of

matrix

Concrete.

(Age

-

Compressive

srrengttr

_

ntajticiiil

Test

specimen

6

in. x

12 in.

--)A,verage

of

"^_llkiogthejob

site

values

given

in

Table

ly.ls

ror

matrix

concrete

and

an

ierage

of

a

M

p.*.i.

(f!x,t0t

kg/cm2)

for

tuUUt"

UuriA

on

basalt

rock

coros

tested

earlier,

-values

for

Ec

of

rubble

"oo.iit,

."o

be

computed

as

given

in

Table

lV.iO.

TABLE

IV.T6

Computed

modulus

of

elasticity

of

rubble

concrete.

cylinder

job

samptes

1958-62

Age

in

days

Particulars

Remarks

28

No.

of

tests

Compressive

strength,

p.s.i.

Modulus

of

Elasticity,

Million

p.s.i.

No.

of

tests

Compressive

strengrh,

p.s.i.

Modulus

of

Elasticiry,

Million

p.s.i.

2820

2.25

3.37

46

76

3330

3.58

4.2s

s2

3130

4-<0

pcy

concrete

3.61

5

4s0(270)

s00(300)

4l

1760

63

Assumed-Matrix

Concrete

65%

Rubble

351

Cement

Modulus

of elasticity

of

rubble

concrcrc

content

million

p.s.i.

(I04

kg/cmz)

(mamix

concrete)

-

--i-

p.s.i.

(kg/cu

m)

950

r.93

8

790

2.r

3.t(221

3.2(22)

3.4(24)

4.4(3t)

4.3(29,\

4.5(3t

)

4.8(34)

4.5(31)

3s30

3.71

500

pcy

concrete

1 in.

:

2.54

cm; I

pcy

:

0.59

kg/cu

m

I

p.s.i.:70.3t

gm/sq

cm

4.14

Temperature

Rise

in

Rubble

Concrete

Heat

of

Hydration

Basalt

Matrix

Rubblc

rock

concretc

l-day

3-day

7-day

28-day

90_day

lgO-day

360_day

43

53

_68

80

89

90

93

Cal/em

Cat/em

Cal/em

Cat/gm

CarTp

Cai/gm

4.14.2

Based

on

computation

from the

heat

of

hyd_ration

and

the

thermal

properties

giyen

io

t"utt

IV.17

below

it

was

expected

ihaf

rubble-concrete

with

a

295

kg/cu

m

(500

pcy),

matrix

concrete

would

rise

in temperature

by

30"

F

for

0.?5

m

(2+

fi lift

and

42o F

for.l.5.m

(5

f!) lift with

a 3-day

interv:al.'However,

it

is

noticed

rhat

the

actual

rise

hai

been

stightly

higLir

for

*e

0.71

m

(2+

ft) lifts

as

discussed

in

tfie

ie.fretature

history

below.

TABLE

IV.17

Thermal

properties

of

Koyna

Dam

materials

and co*crete.

Vc

Ec:

ffn+

I

a

I

)

#r*'

where,

and

Kl:l

-

Specific

hcat, Btu/lb

Conductivity, Btu/sq

ft/Hr/oF

Diffusivity, ftt/hr

Thcrmal

expansion,

Millionth/oF

0.215

0.205

1.0

0.029

3.8 3.1

0.195

1.1

0.030

4.3

where,

7

is

an

empirical

constant

tentatively

evaluated

as 0.785".

t42

:_.+-€itcdj

PHOTO

4.6

: In

situ

permeability

test.

4.15

Permeability

of

Rubble

Concrete..fn

Situ,,

of

percolation

measured.

Photos

4.6

and

4.7

reveal

the set-up for this

'in

situ'

percolation

tests.

Such

tests

have

been

done at

different

elevations

for

different

season.

Eight

such

bores

have

so far

been

tested

to

I to 3 x 10-5

gal/min/sq

ft

of

bore

area.

in

one of

the

monoliths,

the

test

pressure

was

increased

to

TABLE

IV.T8

Percolation

tests

'in

situt

on rubble

concrete-monoliths

of

Koyna

Dam.

Period

of test

Test

No.

Monolith

Bore

No./.-

Depth

No./ele-

distance

(ftl

vation

from

axis

(ft)

(fr)

Bore

Average Pressure

Rate

of

percolation

area

age

of

p.s.i.

under

concrete

(kg/sq

test

(months)

cm)

sq ft

General

Remarks

gall

hr.

min./sq

fr

(Ax

10_5)

litre/

-

min/

sqm

(Bx

l0-3

ll

t0

May

1958

Oct.

1958

3211980

Ut25

7s(s.3)

o.os2o

1,

s0(3.5)

0.0363

I I

Matrix

concrete

cement

content

560

pcy.

Rubble

concrete

approxi-

mately 360'pcy.

Bore crosses

one

joint,

no

wetness

on

face.

B

8

).)

5.5

witP+'+ar''

r43

TABLE IV.IE

(Contd.)

il

8

I

l0

Oct.

1958

Oct.

1960

Nov.

1960

Jan.

1962

Dec.

1962

3

4

5

6

7

8

e

1120s0

10

,,

lI

,,

12

,,

2412060

241

t060

16

2412060

17

2l2r40

3312010

1148

,,

2173

t,

,,

,)

9

5.5

12

17.66

22

t2

17.66

22

12 17.66

22

12

,,

22

12

(Repeat

Test

No.

7)

t2

r7.66

12

17.66

12

17.66

12

17.66

I

16.62

1t

16.62

l

l 15.89

1l 15.89

21

35.5

23*

33.3

-10

l0

10

7

6

50(3.5)

0.0462

14

s0(3.s)

0.014s

1.3

100(7.0)

0.02e4

2.8

50(3.s)

0.0320

3.0

100(7.0)

0.0430

4.0

100(7.0)

0.0s0

5.0

7

6

Matrix

concrete

450

pcy.

Rubble

1.4

concrete

:

292

pcy.

Bore

crosses

1.5

4 No.

2+

ft

joints.

No

wet-

2.0

ness

except

test

joint

5.

2.5

Test

7

repeat

l3

t4

15

rlre

2144

1lt4

1114

1l3e

s0(3.5)

0.030

100(7.0)

0.30

50(3.5)

0.020

100(7.0)

0.047

50(3.5)

0.013

7s(s.3)

0.02e

50(3.5) 0.026

75(s.3)

0.032

2.9

1.5

5.8

2.9

r.9

9.5

4.5

2.3

1.3

0.7

2.9

1.4

2.7

1.3

3.3

1.6

Matrix

con-

crete

:450 pcy.

Rubble

con-

crete

: 292

pcy.

Bore

crosses

3

joints,

2+

ft

lift.

No wetness.

Matrix

con-

crete

:

450

pcy.

Rubble

concrete

292

pcy.

Bore

crosses 2

joints,

5

ft

lifrs.

No

wetness.

l8

UI5

2127

s0(3.5)

s0(3.s)

0.082

3.9

1.9

Matrix

conc-

rete

:

450 pcy.

0'042

2'r

l:""':2s2w'

Bore

crosses

4

joints,

5

ft lifts.

No

wetness.

*Bore

diameter

varies

from

8

in.

I

ft:0.3048

m

;

L4

1

sq ft:0.09229

sq m

;

I

p.s.i.:70.31

gm/sq

cm

;

I

Pcy:Q.59

kg/cu

m

PHOTO

4.7

: In situ

permeability

test.

groutrn_s.

On an

enquiry

made with

the

U.S.B.R.

it was

understood

that

no such

field

tests

have

been initiated

so

far

to study

the

permeability

of

the

concrete

as

laid

'in

situ'.

However.

the

Koyna

project

authorities

felt the

need

for

such

testing

in

the

prototype

as well.

4-16

As

a result

of

these studies

preceding

actual

concretin_g

-and

d,urin-e

concreting,

the specihcations

had

to

be amended

to reduce

thJpenal pircentage

of

rubble

to be

sunk

from

40 to

gS

so ihat

speJd

of

construction

was

not

prejudiced.

More

exhaustive

information

can

be

had

from

ICOLD

1964

Congress,

e-30.

APPENDIX

I

METHOD

OF

TEST

ADOPTED

FOR

DETERMINING

PERMEABILITY

OF

RUBBLE

CONCRETE

CYLINDERS

OF 0.9

m

(3

ft)

dia.

.

The following

m€thod

was

adopted

in determiDing

(d)

0.9 m

(3

ft)

diameter,

l.g

m

(6

ft)

long

and

(6)

the

permeabilitv

of

rubbre

concr-ete

cores

of sizei 0.i m

1r

19

<iian6teiind

b.driiil?iiorg.

L-

-*_*--

145

Along

the

axis

of

the

0,

7.6

cm (3

in.)

diameter

hr

!.42

m

@

ft

9

in.)

in

c:rse

o

rn

case

9f

(D)

so that

at

the

ol-mJection

0.45

m (l

ft

6

i

rubble

concrete

rbmaine,

water

was

measured

at an

hour's

intervar

by

noting

the

fall

of

water-rever

in

the

r"i"

i"oil'oil;rri"riJ,l,

were

continued

until

the

rate

of

percoi'atio;;;;;;i'steady.

Evaporation

losses

in

tnri

main

t""t

;;;;-"*orr"",.o

for.

similarlv

the

assembry

was

modified

and

utilised

for

the

0.9

m

x

0,9

F'

fJli

x

3

ft)

core.

This

assembly

is

schematically

shbwn

in

Figule

4.j:-

, ,

Collidering

the

0.9

m

((:

hole

of

7.5

cm

(3

in.)

dia.

ai

u-n_cler

an

internal

pressun

(150

p.s.i.)

and

zero

externa

stress

distribution

at

vario

would

be

as

given

below:

ength

of

the

rubbte

concrere

mpressive,

strength

[about

,s.i.)

.at

the

age

of

tistl

it

te

will

withstand

the

teniion

ly

any

cracks.

Evaluation

of

permeability

Cofficient

,K,

According

to

Darcy

Law

:

e:KiA.

Considerinn

-,^h_:,

tesr

specim-en

as

in

Figure

4.1,

neglectinq

thel p-ortions

marked

'x,

and

integrating

between

R,

and

Ro.

r.Ot

^:(Ef7;,"t:)

log

e

4L-D)

(R,+a)

Rz*

a)

(R,

-

b)

where'

a

and

b

are

the

sorution

of

the quadratic

equation

x+!

"

In

the present

case

Rr:3.8

cm (l$

in.)

and

Rz:0.45

m

(1

ft

6

in.)

For

these

values

K

works

out

to

K:0.4t*

{__

g

_l

t-zgI

*'rt".tolfl

1.8

m (6

ft)

high

core

the

figure

0.41

(+)

*':o

Radius,

inches

Hoop

152.0

86.0

Tensile

6810

r0.5

6.3

4.5

12

t4

16

18

3.4

2.8

2.4

2.1

r.5

2 4

22.2

stress.

seetion

Y-frrod'ifr'ea'ti'on

of

the

seetion

of

the

rDann

for

a

gB

Trrcglross

storage

in

196r

Y

tu

m (67,i00

M

cu

ft)

diversion

to

rhe

west

for

power

generationl,

went

over

to

trri-it.o

i4fi";

state

now

called

Karnaiaka.

ion

needs

in

the

Bilingual

d

Krishna

valleys

up

to

the

sed

at

about

452,9

M

cu

m

sessed.

-Jhus,

the

final

shape

sto

rage

r

epraced

the

2,7

7

3.

i#

JJ

T

?3r5#,*)

"-,'?:

;

of

the

old

concept.

:,.1 . $

the

beginning

of

Section

III

it

has

been

stated

tnat

the

stage

I

dam

will

be

b*ilt

as

per

truncated

sections

shoin

in

pieuri

e r

l""riul;t;;;;ement

of

about

0.85

M'cu

m

(30

M

cu

ft)

of

tubbr.?oo.r.t".

5.2

Just

about

the

time

of

the

suez

canar

Crisis

(in

1956)

the

contract

was

entered

into

for

tt.

or-.'simul-

taneously

reorganisation

of the

states

on

linguistic

basis

was

on

the

anvil

of

the

parliament,

anda

gifinguJ

Bombay.

wqs

formed

in NovemU.,

f

gi6.-

lil

whole

area

for

which

Irligation

Water

Suppiies

;;;;

to

be

stored

at Koyna

D-am

[over

and

a^Ubu"

;

-l-9

rc.25

r46

Indian National Committee on Large Dams. Design and Construction Features of Selected Dams in India

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