1m drop design

8/9/2019 1m Drop Design

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Design of Vertical Drop of 1 m at Ch: 21960 m of DY-10 under DC-1

DATA :

t of Drop ! 1.00 m

Description U/S D/S

Discharge in the Distributary 0.125 m3/sec 0.125 m3/sec

Bed width of the Distributary 0.40 m 0.40 m

Deth of water in the Distributary !D1" 0.30 m 0.30 m

#ree Board of the Distributary 0.15 m 0.15 m

$ana% Bed &e'e% in Distributary (& 4)2.1*1 m (& 4)1.1*1 m

#u%% Su%y &e'e% in Distributary (& 4)2.4*1 m (& 4)1.4*1 m

#ree Board &e'e% in Distributary (& 4)2.+41 m (& 4)1.+41 m

,round &e'e% (& 4)2.--) m (& 4)2.--) m

e%ocityin $ana% 0.4* m/sec 0.4* m/sec

YD"A#$%C D&'%() :

1* $ength of Crest +$,

$ ! 0.40 m

he %ength of the crest is same as the U/S bed width of the cana%

2* Determination of Crest $eel

ectangu%ar tye crest wa%% is designed

Discharge !"

0.30 m

ead o'er $rest inc%uding roaching ead e%ocity

0.125 1.)4 6 0.400 6 5/3 / ! 0.30 "1/+

eight of $rest 0.30+ m

0.4* m/sec

U/S e%ocity ead

0.012 m

U/S .(.&

4)2.4*1 7 0.012

(& 4)2.503 m

.& of $rest $S& U/S .(.& 8

4)2.503 8 0.30+

$S& &$ ./2*19 m 9

eight of $rest abo'e U/s bed %e'e% 1 0.00+ m

0.4* m/sec

D/S e%ocity ead 0.012 m

D/S .(.&

4)1.4*1 7 0.012

(& 4)1.503 m

1.)4 6 & 6 3/2 6 ! / Bt "1/+

where Bt !crest width"

U/S e%ocity of aroach !a"

a2/ 2g

U/S #S& 7 ! a2/ 2g"

D/S e%ocity !d"

d2

/ 2g

D/S #S& 7 ! d2/ 2g"


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* 'hape of the Crest

& of crest 8 D/S Bed %e'e%

4)2.1*- 8 4)1.1*1

1.00+ m

0.55 1.00+

0.552 m

Say 0.+0 m

.* Calculation of Cistern Dimensions

a" Deth of cistern :

1.00 m

: 0.11 m

'a 0.15 m

b" By arshney ;ethod

: dc/3

where

< 0.313 cumec/m

dc 0.215 m

Deth of cisterndc/3 0.0-2 m

dot Deth of $istern 0.15 m

$istern &e'e% D/S Bed &e'e% 8 :

$istern &e'e% (& 4)1.041 m

$ength of cistern

&ength of cistern 5=>&

2.)0 m Say 3.00 m

?ro'ide 3 m of %ong cistern at .& of 4)1.041 m

3* Design of Curtain 4all

@idth of $urtain @a%% on U/S A D/S assumed 0.30 m

a" D/S $urtain @a%%

Deth of water

7 0.+02

0.3 / 2 7 0.+0

0.-50 m

Say 0.-5 m

b" U/S $urtain @a%%

Deth of water

7 0.+03

0.3 / 3 7 0.+0

0.-00 m

Say 0.-0 m

$rest width at to Bt 0.55

2

2 eight of $rest abo'e D/S Bed &e'e%

2

$rest width at to B t

!1/4" 6 ! 6 & "2/3

& ead &oss

dc


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6* %mperious 5loor

his e6tends from U/S $urtain @a%% to D/S $urtain @a%% . he f%oor shu%d be designed to resist the ma6imu

Ustream of the weir the Emer'ious #%oor may be of th 0.3 m !nomina%" as the deth of water itse%f wi%% co

#%oor &ength 1.5 6 D 0.450 m

Say 0.50 m

$a%cu%ation of U%ift ?ressure

ead of @ater causing U%ift $S& 8 D/S $B&

1.00- m

!1/3" n 7

&w 1/3 !0.5 7 0.+ 7 3 7 0.3 7 0 .3" 7 ! 0.- 7 0.00+1)-+14+-)*35*2 7 1.00+

&w 4.1-* m

1. $ree %ength at t

1/3 !0.5 7 0 .3" 7 ! 0.- 7 0.00+1)-+14+-)*35*2 7 1.00+ 7 0.15"

2.12* m

u%ift

u%ift ?ressure 0.4*4 m

h re


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Chec for 'ta7ilit of Crest 4all :

0.+0 m (& 4)2.1*- m

1.15+ m

(& 4)1.041 m


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Soi% tye B$ Soi%

Soi% roerties G

f

1.)0 t / m3

0.333 0.333

eight of $rest wa%% (& 4)2.1*- 8 (& 4)1.041 1.1+ m

0.5 6 0.333 6 !1.)0 8 1.0" 6 !1.15+

0.1-) t / m8erturning oment :

0.1-) 6 1.15+ / 3 0.0+* t 8 m

@t of concrete 0.+0 6 1.15+ 6 2.4 1.++5 t

'ta7iliing oment :

1.++5 6 0.+0 / 2 0.50 t 8 m

#.H.S. against o'erturning 0.5 / 0.0+* -.25 91.5

m 0.+5

#.H.S. against o'erturning 0.+5 6 1.++5 +.0- 91.5

0.1-);ase


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!assumed"

(& 4)1.4*1 m

ence HI


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U%ift ressure %ie%y to be occured.

nter ba%ance the U%ift ?ressure.

0.157 0.-5"

0.75 m


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!Safe"

!Safe"

10 m

0.330 $umecs/m

0.51 m

0.-+ m

0.4+ m0.50 m

is adoted.

!S "

1m drop design

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