Indian National Committee on Large Dams. Design and Construction Features of Selected Dams in India
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5.1
Masonry
Dam
The
maso/rry
dam
comprises
the following
com-
ponents
:
at the Ukai Dam
since
1970,
i.e.,
pre-impounding
con-
ditions.
The
observations
indicate
that there
is
no
change
in
the seismic status in the
post-impounding
conditions
even
after the
period
of
5
years.
5.
Layout
power
house. The
quantity
of
masonry
and
concrete
involved in
the
masonrv
dam
was 1.51
million
cu
m.
5.2
Power House
and Ancillary
Works
The
penstocks
are fabricated
from 18
mm
to 25 mrn
thick
fire box
quality plates.
The
turbines for the
gene:
ration
of
power
have
capacity
of 1,00,000
HP
each
and are
of
Kaplan
type operating under
a head
varying from
57.3
to 34.44
m.
The
alignment
of tail-race
channel
for the
power
house was
finalised
after
model
studies
at Central
Water
and
Power
Research Station,
Pune.
The
channel
53.35
m
wide,
and
995.17
m long
up
to
river,
is
designed for maximum
discharge
of
736.23
cumecs.
The
channel involved 835.34
M
cm excavation
in
overburden
and 588.98
M
cm of excavation
in
rock.
5.3
Earth
Dam
The
earth
dam
which
is 4058
m long
(excluding
small
saddles)
comprises
the following components.
st.
No.
Dam reach
Length lleight Total_quan-
m m tity of
work
Thousand
cum
sl.
No.
Compdnents
1.
Left key
and transition
2.
Power
dam and non-over-
flow
section
3. Spillway
4. Right
tranbition
and key
5. H.R. Dam
Length
m
20r.r7
t27.7
426.2
t27.25
145.84
Height
m
61.87
61.87
64.92
66.r4
35.53
398.08
944.0
tt52.t5
r
136.1
5
426.72
68.58
47.24
35.0s
39.62
28.96
3.
The lefc
tjransition
portion
provides
a suitable
junction
with
the earth
dam on
the
left side.
The
long.
Gorge dam
Rieht bank
earth
dam
Right
bank
saddle
dam
Eanh
dam
between
hills
No.
I
and
2
on
left bank
including
envelope
5.
Earth
dam between
hills
No.
2
and
3
on
Ieft bank
6. Other saddle,
etc.
7051
3100
5267
75s
133.3
below
it. At
extreme left
end of Ukai
l)am,
there
is
145.84
m long
and 35.53
m high masonry
dam through
which
two
outlets, each of
2.13 m
x
2.7
m
size
are
provided
for
aldmitting discharge
of
35 cumecs
into
the left
bank
main
canal.
This stretch
of
masonry
dam
also
accommodates two
penstocks of size
3.96
m
X 1.98 m
for admitting
water
to
the
390 MW
canal
Total
The
total earth
work
involved in earth
dam
is
thus
23.67 million
cu
m.
5.4
Diversion Channel
In
view
of
large
quantities
of
work
(7.36
M
cu
m)
involved
in earth dam construction
in the
river
portion,
the
construction
period
was
spread
over
three
working
seasons.
As
the
floods
could not
be
allowed
to
pass
over
the
partially
raised earthen
dam,
in the
inter-
vening two
monsoons the
river
had
to
be
suitably
divert-ed
through an
open cut diversion
channel.
The
249
70
I
Hill
No.
I
80
7or
tlnc
9rn
wide
rOodn6y
bP
of
dom
p.g.
;11.
R.L.
lO5.l56m
70
65
-80
z
NO
gverflow
6s6
Hitl
.No.3
;R.T.
Dom
t-
f6.2am
Key
FounootionlEEl
ofiH"E
g
el
5t
(D
@
F
o
o
o
o
o
(o
8s
o:
N@
?\rt
oo
3g
Cho,nogg
o
Fg
s
{B
EB
o
(r
d
c,
t
o
c,
e3
r)
ra
@6s
Es s
UPstreom
Elevotion
'olo
o
-o
o
-o
diversion
channef
as
shown
in
Figure
3
was
about
234
m
wide.
tz.it-m
"lir]
uoc
u6oui
-zo'm
deep,
perhaps
largeit
a
ivirsi&,'i"o'?i.
world.
5.5
Canal
Systems
-
The
Ukai
left
bank
cr
the
reservoir
through--a
-;
extreme
left
end
of
Ukai
n
cm
thick
in
rhe
bed
and
The
Ukai
right
bank
main
canal
off_takes
from
the
existing
Kakrabar-
canal
una
envisages
irrigation
in
area
of
67,ir0
rr..Lrr
il
irr
not
found
feasibre
250
to
take
a
hish
'ever
canal
on
the
right
bank
from
the
Ukai
Dam
is
the;1,effi#
il'un..r.,
a
very
difficult
terrain
along
rhe
rivEr
b;[
iol.
u
length
of
:g
km.
It
was,
therefore,.
p_roposed
ro
tate
ofr-it,,
iliui
right
bank
main
.uni1
'f;;;"
il
;:
r
sz.s
m
o-f
tiJ
"^rrtiog
f:l::f:t
:ieht.-ba"f
;;i"
canal
near
village
rad_
Keshwar.
The
Kakrapar
main
;;;"f
fi
,"
,f,i,
reach
is
widened
to
accommodate
the
.additionai
fr's.rrurg.
of
the
Ukai
right
bu"k;;;ii
"unur.
The
Ukai
right
bank
main.
canal
is
designed
as
a
conrour
canar
up
tg
48
km
ioo
ilr;;
-ii;a;ned
as
Hansot
branch
""ll"l^r1.;:;"-r'-+
of
24
km.
ThJre
are
two
other
branches-named
as'Kosamba
branch
3g
km
and
Jitali
branch
12-
linl
-iil
toral
.length
of
.right
bank
main
canar
u.no
-Lluo.lh^'"canars
is
[zz
km.
The
capacity
of
the
rnain
canal
ui
tr.uO
is
4t.0-c-;;;;s.
6.
Land
Acquisition
and
Rehabilitation
The
total
lan.d
acquired
for
th,
reservoir
basin,
dam
sear
and
for
the
prirjeci.t-ronirs
totalred
60,g02
FIGURE
3
:
General
layout
of
Ukai
Dam.
PHOTO
t :
View
of complete dam and reservoir.
was
formed.
The
land
aquisition
and
rehabilitation
The families,
who were
deprived
of
their
natural
habitants
were liberally
compensated
for their
land
and
property.
The
land
upto
F.R.L.
R.L.
105-16
m.
(345.0
ft)
was
acquired.
The
land between
F.R.L.
and
H.F.L., i.e.,
R.L.
105.16 and
R.L. 106.98 m
was
not acquired
but
the
hutments
coming
in
this
belt
were
got
shifred
after
compensating
adequately.
The
area
so
covered
was
spread
over
4
talukas
of
two districts-(l)
Surat
and
(2)
Broach.
ln addition to
the compensation
for
the
land
the
TABLE
VI.l
Salient
features
of land
acquisition
and
rehabilitation
programme.
1.
Name
of
districts
affected
l.
Surat
of
Gujarat
.
2.
Broach
-do-
3. Dhulia
of
Maharashtra
2.
Name
of
talukas
affected
:
l.
Songadh
of
Surat Distt.
2.
Uchhal
-do-
3.
Nizar
-do-
4.
Sagbara of Broach Distt.
5. Nandurbar
I
of
Dhulia
6.
Navapur
iDistt.
of
7.
Taloda
I
Maharashtra
J State.
251
TABLE
Yl.t
(Contd.)
3.
No.
of
affected
villages
: l4
of
Songadh
Taluka
59
of
Uchhal
-do-
5I
of
Nizar
-do-
-1r
of
Sagbara
-do-
170
I
Dhanora
of
Nandurbar
2
Dhayate
of
Navapur
Taluka
I
Taloda
of
Taloda
Taluka
3O352
ha
I 156g
,,
22259
,,
(b)
No.
already
to
of
khatedar
distributed
4.
fola!
area
affected (at
F.R.L.)
(a)
Occupied
Agrl.
land
(b)
Govtl
waste
land
(c)
Govt.
forest
land
Efect
of
water
reservoir
upstream
from
the
dam
.{o.
o-f
villagcs
rehabi_
rltated
Tq.
qf
affected
families
:
(a)
Agricultural
(b)
Non-agricultural
8.
\lr.
of
private
houses
atlected
9.
Nos._of
families
shifted
(a)
Rehabititation
- -ii
17
groups
of
settle-
ment
(b)
Moved
away
on
acc€pting
ad
hoc
grant
10.
Land_of
cleared
forest
actually
distributed
foi
agricultural
purpose
(a)
Area
64178
ha
:
103
km
:
138
in
17
groups
of
settlement
:
8776
:
7224
11.
Allorment
of
residential
plots
12.
No.
of
drinking
water
wells
13.
No.
of
school
buildings
constructed
105
14.
No.
of
public
and
reli-
glous
building
construc_
ted
M4
il;i
ald'-ii?i:n
roads
N9,
oL
internal
roads
with
C.D.
works
Lift
irrigation
scheme
Check
dams
No.
of
fruit,trees
supplied
jg affected
ropli
ai
l.rovt.
cOSt
Rural
Electrification
in
setflement
area
so34
16280
r63
5.
6
7.
15.
16.
43
t7.
18.
19.
108
lt
15
16000
:
25133
14148
r932
]
,uo,o
20.
21.
Soil
conservation
22.
Public
conveyance
23.
Total
outlay
as
revised
pro;ect
estimate
12,000
plants
Rs.
9.8
r.nillion
given
for
nrgn
tension
line
and
other
constructional
works
for
erectrrfication
of
Uchhal.
5t?ar
and
Sagbara
Talukas.
Contour
building
works
are
carried
out
in
405
ha
S.T.
buses
have
been
al,ransed
to ply
througli
all
the
new
seftlement.
Rs.
12.31
crores
7378
ha
7.
Design
of
Earth
Dam
7.1
Introduction
252
Part
fl-Design
7.2
Construction
Material
It
was
planned.
to
use
material-
of
compulsory
excavation
of
diversion
"haooei-i,
"ooition"io'ih.
ur"
of
material
from
specified
b;;;;*
areas.
(i)
The
diversion
channel
Taterial
was
generally
silt
of
low
_plasricity
foiminj;t;'
;i;'iirru.".
About
6
lvt
cu
m
o-f
thii
material
was
available-
st.
No.
Earth
dam
reach
Length
Max.ht
m
above
G.L.
m
TABLE
VII.I
Details
of
earth
dam in
various
reaches-
7.3
Zoning
of
Earth
Dam
(i)
The
zoning
of
eartl
ced
by
maximum
alluvial
silty
soil
excavation
of
diver
sloping
core
was
pl
much
silty
soil
as
p
side.
The
use
of
sirty
-
soir
was
restricted
to
the
down-
stream
zone
beyond
chimney
firter
with
a-
Joner
of
relativety
more
:,*1.
semi-pe?vi*,
-ut.iiufl
6n
up_
:11:?-,.:ilry.
soit
was
used
bnty
betow
the-io;
warer_
rever
wrth
adequate
cover
of
stable
material
so
that
it
had
not
to
withstand
the
iiug.
-
or
sudden
drawdown
during
reservoir
operation.
dhirn.y
sand
firter
and
horizontal
sand
firter
were
introduced
for
effective
drainage
of
seepage
water.
Attempts
were
made
to
L9.p
the
inclined-
filter
as
near
tte
"or.
u,
f,ossibre.
The
central
S.P.
material
of fir", vnriefw \rrqc in*rn_
duced
between
clay
core
as
to
satisfy
the
standard
fi
tal
filter was
provided
near
th-e
dams
except
the
main
earth
dam
in
the
river
where
the
river
iand
will
act
u,
u ntt.r.
(ir)
soft
loamy
organic
cray
was
encountered
in
the
right
bank
vailey
at ch.
3200;.
-ih.-in'aterial
was
liabre
to
high
-sertrement
but
ttre
-iate
of
settrement
was
quite
low-
vertical
ild
drains
Total
quantity
of earth
work
Million
cum
1.
Earth
dam
between
Hill
Nos.
2
and
3
2.
Earth
dam
between
Hill
Nos.
I
and
2
Earth
dam
in
main
gorge
Right
bank
earth
dam
Right
bank
saddle
dam
Total
28.96
0.7s
39.62
5.10
68.58
7
36
47.24
7.Os
35.05
3.10
427
3.
4.
5.
1 136
398
945
tt52
4058
23.36
TABLE
VII.2
Properties of
soils
used
in
earth
dam.
SI.
No.
Type
of
Zone
Mechanical
Analysis
Atterberg's
Iimit
Compaction
Shear parameters
perme_
Clay
Silt
Sand
<0.002
0.002
0.06
mm
to
to
0.06
2,0
mm
mm
Gravel
)2 mm
L.L.
P.I.
M.D.D.
O.M.C.
C
in
em/CC
%
kg/cma
6in
degree
ability
in
10-o
cm/sec
l3
t2
l1
10
14
1 Impervious
)
-
,,
15
t7
20
I
3
o
0
5
53
54
s2
30
7l
r5
r0
25
19
22
22
59
25
52
40
50
l3
7
6
10
1
33
50
20
52
49
54
30
33
25
30
29
NP
NP
NP
NP
NP
NP
NP
NP
r.59
1.59
1.60
l;62
r.59
1.84
1.85
1.78
24
22
26
28
27
28
NP
NP
23.6
0.201
2L.6
0.310
22.s
o.29
18.7
0.106
22s
0.109
14.6
0.137
13.8
0.222
33
0.93
30
0.308
35
0.25
3s
0.76
37
1.44
35.5 1299
36
3026
I
2
I
2
3
Random
Available
from
diver-
sion
channel
Semi-pervious
-do-
-do-
l5I
13.6
o.t12
36
253
were
rnstalled
in
this
valley
to
accelerate
the
foundation
consolidation
and
thereby
reducing
the
unequar
post-construction
settrement
of
roundatron
and
em
also
serve
a
sec(
as
relief
wells
tr
Auger
holes
of
through
out
this
5
cm
dia.
pgrtion
was
filled
up
with
fine
sand
of
intermediate
gradation
so
as
to
satisfy
the
filter
criteria
.and
prevent
chocking
of
the
central
sand
drain-
The
top
*ut
"orJred
rvith
0.6
m
thick
coarse
sand
piatform-
f.ua;ng
to
river
bank.
(nT)
On
account
of
standing
pool
of water
of
5
m
depth
due
to
back
watJr'effect
of-kakrapai
weir,
dredged
sand platform
6-7
m
depth
*u,
Iaid
over
the
existing
river
bed
deporii'ro.
12 m
depth.
ffir^ permitied
Jaying
of
compacted
earth
work
for
construction
orearth
dam'in
the
river
gorge.
The
field
investigari""
tV
Oynamic
and
static
cone
penetrometeirevealei
tlrat
the
dgtrlty
of
dredged
gand had
relative
-density
of 40-45
percent.
The possibility
of liquefad_
tion
of
the sand
used
was
bxaminid
by
shaking
table
rests
at
School
of
Earthquake
Rngineering,
Roorkee.
.The
tests
indicated
that Ukai
sand
does
not
liquify
under
a.nticipated ground
motion.
Large-
roikfills
at
the toe
yet:,
however,
provided-for
conflning
the
dredged
sand,
as suggested
by
the
U.N:
experts.
7,.4 Evaluation
of Earth
Dam
Section
254
as
construction
pore
pressure
for
sirty
soir
of
diversion
channel.
(i)
Construqion
condition
(ii)
Operation
condition
(lfi)
Sudden
drarvdown
condition.
average
and
minimum
v
respectively.
The
stabititv
anarysis
of
downstream
srope
of
the
embankment
was
also
carriro
*t
f";
;;;.;u"Ji
op.rut-
ing
condition.
The
shear
paiameters
were
adopted
as
obtained
for
saturated
soils.
The
minimum
factor
of
safety
of
l-5
and
I.0
was
consioereo
as
acceptable
for.lower
average
and
mini-u-
varue
"r
trrlli
para-
meters
respectively.
The
stability
o.f
s]opgs
and
foundation
was
also
verified
by
the
mettroo
;i;;;osite
failure
surfaces.
(iu)
stab-ility
Analysis
under
Earthquake
conditions
:
Stability-
of
slopes
and
foundatLn
due
to
horizontar
earthquake
acceleration
of
O.iS
g-;ur-"rt.""i.0
o'
computer
with
following
conditions.
TABLE
VII.3
Design
constants
of difrerent
zone
of
earth
dams.
Earth
dam
section
Zone
M.D.D.
lb/cu
ft
o.M.c.
Cohesion
Ib/sq
ft
Tan{
Pore
pressure
Const.
and
SDD.
Oper.
cond.
above
Phreatic
Iime
Earth
dam
between
Hill
Nos.
2 and
3
Impervious
Semi-pervious
Pervious
Sand
filter
Foundation
97
t07
t2L
120
90
(F.D.D.)
97
ro7
'90
120
90
(F.D.D.)
21.0
12.83
10.00
8.r0
I
1.5
\2500
1400
0
0
1700
2500
1400
660
.
0
1700
0.30
0.60
0.70
0.70
0.35
rw%
,t
l2s
1
5
l0O
r25
.100
50
r00
I
100
ns
100
50
50
100
125
'1
i
1200
960
0
0
0
Earth
dam
between
Hill Nos.
I and
2
Main
Gorge
Earth
dam
Right
Bank
Earth
dam
Right
Bank
saddle
dam
fmpervious
Semi-pervious
Random
Filter
Foundation
Impervibus
Semi-pervious
Random
fill
Filter
Rock
Zone
Silt
Zone
Foundation
Impervious
Semi-pervious
Random
fill
Filter
Rock
Zone
Foundation
Impervious
Semi-pervious
Pervious
Filter
Foundation
100
(F.D.D.)
95.20
r r3.00
97.40
120.00
r00.00
90.00
(F.D.D.)
95
105
lt6
t20
94.5
(F.D.D.)
2t.o
12.83
r8.0
8.1
I
1.5
0.30
0.60
0.55
o.70
0.35
r00
100
r00
1400
1000
660
0
0
90
105
90
120
100
25.0
r
6.30
18.20
8.10
2s.o
16.30
18.20
8.10
0.40
0.65
0.55
0.70
0.75
0.60
0.40
0.60
0.65
0.70
,1'
0.45
0.65
0.73
0.70
r25
t2s
:
1400
0
0
20.7
I6.5
8.1
8.1
t2.0
(F.M.C.)
I
lb/cu
ft
-
16.0t8
kg/cu
m; I
lb/sq
fr
:
4.88
kg/sq
m
255
-
(l)-
upstrea-m
srope
of
earth
dam
was
checked
for
operatine
condition
*ittr
uarious
erevation,
o}..rervoir.
The
sudden
d;til;;n""ti?irion
was
not
combined
with
earthquake.
(2)
The
stab'ity
of
downsrream
srope
was
checked
for
normar
operati"g
;o"dition
*ittr
fulr
reservoirlever.
,,,
;llii"-:ll*:rn
facror
of
safety
was
more
than
unity
-
(t)
50
percent
of
rock
forming
rip-rap
shourd
have
an
average
diameter
of
3g
cm
;
(rri
rirtnfuii*u-
size
of
the
rock
shourd.
be
upro
60
cm;
(iif)
et
i.uit-60
per-
cent
of rock
should
weigh
45
kg
each.
rve
upstream
semi_pervious
gu.arry
sparrs
(7s
.mr
ro
t;8t'jJXf:)
T*.il#$
^b^.I",T- 1ip-rup
and
abovl
-.iurTuv..;i";;psfteam
seml-pervious
material.
Typicar
sections
for
earth
dam
between
hilr
Nos.
I
and.2,
and
for
main
e..i;";
given
in
Figures
4
and
5
respectively.
8.
Design
of
other
Appurtenant
Works
The
desier
:I-{:lt"yiTg
appurrenanr
works
of
Ukai
Project
is
summansed
below
:
(i)
Masonry
dam
and
spillway
(ii)
Outlets
;
(t7i)
Gates
i
and
(iu)
power
house
8.1
Masonry
Dam
and
Spiilway
The
masonry.
dam,
in
Ukaj
project
comprising
spillway,
power
itu,o,-t*oritiJ"'
o"rn,
etc.,
was
.located
on
the
left
bank
terrace
due
to;ili"ii;;iJf"rluroor.
(i)
The
foundatio.n.
grqde
rock
was
available
rerativerv
at.highei
elivation
on"ih.
rlii
uunt
than
in
itre
rivei
L.a.^-'"
(tr)
There
was
a
standing
pool
of
water
in
river
due
to
Kakrapar
weir
uUooi'gO
downstream.
(ffr)
The
l1vou1
was
convenient
from
river
diversion
consideration.
-
The
length
and
maximum
height
of
spillway
power
dam,
transitions
dams,
at".,
ur"ts
under
:
the
km
As
most
of
.
the
semi_pervious
material
is
of
finer
y_arjetl,
.a
mul
ti-layer
fi
lter'
consi
stir;;i;;sheo
stone
trl
two
lavers
(one
consisting
of
iru-rhi.i..i"r
below
20
mm
siie
utiq
il;;il'c3nsisting
of
metar
above
]!3r :ir,.)
pnd
quurry-
,furt,
(zfmm
^iJ'*r50
__
srze)
would
have
been
necessary
according
to
conven-
tional
filter
criteria.
rrie-naturar
rivei
sand
had
rctically
the
same gradation
as
that
;i;;-i-;ervious
terial
and
hence
mitar
berow
t0
;;;iir'rr"i-i;'";;
:ained
-by
crushing
metat
which
wo;iJ
il;;.
been
y
costly.
It
was,
therefore,
examined
in
the
oratory,
whether
metal
layei
(tiner
;dn
20
mm
:)
could
be
disp^ensed
with,
r".itin!
to'iir.
stigrrtry
:_riu^1_
nature
of
.
upstr.u-'
r..i-p.?riou,
taterial.
was
removed
from
the
filr;orrl.rlli,'i;
,'ffi
Hil'o"l}T
the
exrent
of
one
million
i"d;r.
ection
:
For
efficient
drai-
slope
drain.
The
water
s
drained
through
30
cm
d
below
each
draln
pit.
256
sr.
No.
Particulars
Length
m
Height
m
l.
2.
a
J.
4.
Spillway
Power
dam
and
non-overflow
dam
Left
key
and
ieft
transition
dam
Right
transition
dam
and
right
key'
425.2
127.7
201.r7
64.92
61.87
61.87
The
dam
ygr\s
involved
.I,20g,g39
cu
m
of
masonry
and'
214,624
cu
m of
concrete.
The
masonry
d_am
was
foundejl
on good
basaltic
rock
intruded
yj.,,-.rtr.
d),{;
-Due_
to
the
presence
of
red
bole
lavers
in
some
brocks,
foundations
were
taken
deeper.
Comprehensive
model
studies
ye.re
carried
out
at
c.w.
&
-p.R.s.,
pune
Gr";r-ivolving
-fi;;i*
design
U/S slopc
to
bc
profcctcd
by
O.6m
th. Riproo
ond O'3n nalol
loycr-.'
I
R.t92'.99q-
a9
38n
R_L OA
48m
R--.97'54m
,
3.5
1r_
:t.22
m
rcmi-pqrviout
R
efe
re nc
es
I
lmpervious
moteriol
2.
Semr-Pervious
rnoterrol
3
RonOom
fill
{Moterrof ovorloble
from
excovotion
of D
C
d.
Filler
FIGURE
4
:
Cross-section
of
the earth dam
between
Hill Nos.
I
and
2-Ukai
Project.
O'6On
I lLraDrop
O'oon
lh. filt.r
loyara
D.br
riproP
R
R. L.89.92m
6.
t4
o
9936s.5s,n
Coorsc
S.P
Refe:-enccs
l.
lmpervious
zone
2.
Semipervious
zcne
3. Rondom
zone
4.
Sond
filter
5.
Rock
zone
6.
Silt
zone
.
7.
Sond ond
S.
P
Loyers
zone
FIGURE
5
: cross-section
of the
earth
dam in
main
gorge-ukai
project.
of
spillway,
energy
dissipation
arrangements
and
length
and
heighr
of divide walls
on either side
of
the
spillway.
flg
design
aspects
of
spilhvay,
po\\'er
dam
and
transition
dam are
discussed
below
:
an
offset
on
the
upstream
side
to affect
economy in
the
section.
The
cross-section
of
spilhvay
is
given
in
Figure
6.
The
-stability
analysis
of
the
section of
spillway
was
carried
out based
on
the
following
data
:
(i)
Seismic
coefficient
of
0.05
g,
modified
to
0.1
g
after Koyna
Earthquake
of I
t
December
1967
and
Broach
Earthquake
of
23
March
1970.
(ii)
No
tension
to
be
allowed
in
general.
@,F
257
f-'c'rc{
FIGURE
6
:
Cross-section
of
spillway_Ukai
project.
gggqQ1gar
R&99''a,n_
Axl:
of N.O.F.
Ax|s
ef
6.rrt
a
R. L.gt.
13
,r.
R.L-89.29n-*
fL!=.9E:!fil_
R.L.Ot.OBmJ
....on
R1.95.7t
r
tn
D/.S
Roce
clLT#JP;r-""*
I
Drvide
woll
I
f
.'l
t?
A|
o
E
ljlln
I
ji
szeLr.s.Ptffi
:A/"13!T."7:"
B'.o.-J
20'66n
t
dFo;nog.
hot.5
.
(v)
Uplift
pressure
at
tJ
)ry
?nd
that
between
the
,nd
the
toe
was
assumed
to
power
dam
is
located
in
y
with
a
35.66
m
of
non-
)en.
It
consists
of
four
,"0ffi1""""T'":1.:JirJ,.T
258
(rd
Maximum
compressive
stresses
to
the
permissible
limits.
(iu)
Weight
of
masonry
24}0kg/m'.
be
within
to
tlre
scroll
case
in,
the.
power
house
through
reducer
FffS:;
,.th'
cross-sectl6;
;i
;;;"'
dam
is
as
per
In
the
stability,
ary1lysjq,
the
trash
rack
structure
was
not
considered-
Th;
brock-analysis
carried
out
for
the
stab'irv
of
rhi
d;;
i"oJi.lt.o
a
maximum
tension
of
l '08
ke/im2
ar
rh;
ii;i;;;..
FRi
;irh
lultnquur"
conditionl'
Howe-ver,
tnii
ienslon
would
reduce
if
the
trash
rack
which
i;'
;;;;riirri"_witrr
the
dam
section
is
considerect
in
the
,t"Uiiiiv
i,iatysis.
(c)
Transition
(Right
and
Left
Da@
:
The
non_over_
flow
section
with
i"p
*iOit
?t+_o'
i, provided
with
upsrream
batter
of
1-in
12
below
RL,
g6.g
7
anddown-
stream
batter
of
0.7
:
t
Uef
ow
nI,
.
qT.
i;;:
.'"
The
stability
analysis
is
carried
out
for
NOF
section
indicated
u 'ouii*um
tJorion
oib.qa"'kg/cmz
at
foundation
leve-l
""0.i^
enr.
condition
with
fu'
uplift
and
earthquake,
----
(d)
View
of
the
Designs:
The
designs
of
masonry
dam
were
finaiised
"d;;;;;
'a"
seis.ic
coefficient
of
0'05
g
prior
to
the
occurrence
of
earthquakes
at
Kovna