Canal Syphon Programme

Office of Director Dam I.D.R., Jaipur

66591175.xls

DESIGN OF A CANAL SYPHON

NAME OF PROJECT :

Case study, Design example 9.4/p394

DESIGN INPUT DATA :

(a) (a) Cana Canal l (i) (i)

Full Full supp supply ly disc discha harg rge e of of can canal al

40.00

Cumec

(ii)

Bed width of of ca canal

18.00

m

(iii (iii))

Full Full supp supply ly dept depth h of cana canall

2.10

m

(iv) (iv)

Bed Bed leve levell of canal canal (C. (C.B. B.L. L.)) at D/S D/S

(v)

Side slope lope of cana canall (s) (s)

(vi) vi)

Free Free boar board d of of can canal al

250.00 m 1.50 :1 0.75

m

(b) (b) Drai Drain n (i) (i)

Max. Max. obse observ rved ed floo flood d dis disch char arge ge

100.00 cumec

(ii)

Bank le level

254.00 m

(iii)

Bed level

251.80 m

(iv) (iv)

Highe Highest st Flood Flood Leve Levell (H. (H.F. F.L. L.))

253.25 m

(v)

slope

1/600

HYDRAULIC DESIGN : (1) Section of the drainage channel According to Lacey's formula = 4.83 X Q 1/2 = 4.83 X 10 = 48.3 Provide bed width of the drain at the crossing P

=

44.50 m.

(2) Canal waterway Bed width of canal Normal X-area of the channel (A)

= = =

18.00 m. BD + 44.42 Sq.m.

Velocity in the normal section

= =

Q/A 0.90

sD 2

m/sec

Adopt size of the barrel as Width

=

Program by- Sunil K Goyal

3.00

m,

Wall thickness

Hydraulic 1

=

0.30

m

Checked by - P.P.Pareek


Height

=


2.50

m,

No. of barrels

Hydraulic 2

66591175.xls

=

2

No.



Reduce the canal waterway from Velocity through the barrels

=

18.00 m 40 15

66591175.xls

to

6.30

=

2.67

m/sec

<

6.00

m/sec

m

The veloci velocity ty is is within within the recomm recommende ended d range range The size of the the barrel barrel is, therefore therefore okay It should be checked that the flow is subcritical in the barrel, .i.e., Froude number (F) should be less than unity Now F = V/(gd)1/2 Where, V = 2.67 m/sec g = 9.81 m/sec d = 2.50 m Therefore, F = 0.538 Since nce the the val value of F is less ess than han 1

the the flow flow will be subc subcri riti tica call in the barr barrel el

(3) Head loss and bed levels at different sections : Width of canal in the flumed portion Provide 2 in 1splay in contraction and

=

11.70 Length of contraction transition = -------- X 2 11.70 Length of expansion transition = -------- X 2 Assume,Length of the barrels in the flumed portion=

6.3 3

m in 1 splay in expansion transition

2

=

11.7

m

3

=

17.55

m

70.0 m > 68.50 m assumed length is O.K.

In the transitions, the side slopes of the section shall be warped from 1

2

3

1.50 : 1 to vertical. 4

0.3 m Thick Thick wall Canal 18.0

6.3

18.0

R.C.C. barrels 11.70 1

70.00

17.55

2

3

Canal waterway


Hydraulic 3

4 (All dim in meter)



66591175.xls

At section 4-4 Area of section = 44.42 Sq.m. (Normal channel section) Velocity = Q/A = 0.901 m/sec 2 Veloci Velocity ty head = V /2g = 0.0414 0.0414 m R.L. of bed = 250.00 m (g (given) R.L. of water surface = 250.00 + = 252.10 m R.L. of T.E.L. = 252.10 + = 252.141 m

2.1 0.0414

At section 3-3 Water depth at the entry and exit of the barrel should be kept slightly higher than the depth of the barrels so as to keep the ends of the barrel submerged for proper syphoning Provide water depth equal to 3.00 m Area of section = 3.00 X 6.3 = 18.9 Sq.m. Velocity = Q/A = 2.116 m/ m/sec 2 Velocity head = V /2g = 0.22 0.228 8m Loss of head in expansion from section 3-3 to section 4-4 0.3 (V22 - V12) /2g = = 0.056 m Hence elevation of T.E.L. at section 3-3 = 252.141 + 0.056 = 252.197 m R.L. of water surface = 252.197 0.228 = 251.969 m R.L. of bed = 251.969 3.00 = 248.969 m From section 3 - 3 to section 2 - 2, area and velocity are constant. Head loss through barrels Head loss through barrels is given by ( 1 + f 1 + f 2 xL/R )V 2/2g = Where,

Where,

f 1

=

0.080

f 2

=

a(1+b/R)

a

=

0.00316 , b

L R

= = =

70.0 m A/P 0.682 m

,for bell mouthed syphon

=

0.10000

Hence, f 2

= 0.00362 Ther Theref efor ore e loss loss of head head in barr barrel els s =


0.52 0.526 6 m

Hydraulic 4



66591175.xls

At section 2-2 R.L. of T.E.L.

= = = R.L.o R.L.off water water surfac surface e = = = R.L. of bed = =

T.E.L. at section 3-3 + head loss through barrels 252.197 + 0.526 252.724 m R.L. R.L. of T.E.L. T.E.L. - Veloci Velocity ty head head at sectio section n 3-3 252.724 0.228 252.495 m 252.495 3.00 249.495 m

At section 1-1 Loss of head in contraction transition from section 1-1 to section 2-2 0.2 (V22 - V12) /2g = = R.L. of T.E.L. = = = R.L. of water surface = = R.L. of bed = =

0.037 m T.E.L. at sect ection 2-2 2-2 + hea head loss oss in contract action trans ansition 252.724 + 0.037 252.76 m 252.76 0.041 252.72 m 252.72 2.10 250.62 m

(4) Transitions The general method of Hinds shall be applied for designing the transitions, as the water depths in the transitions vary from 2.10 m to 3.00 m (a) Contraction transition w.s.profile 1 R.L. 252.72

2 y1 = 0.112 x1= 5.85

R.L.

252.50

1 11.70

2 (All dim in m)

Contraction transition y1

= = =

x1

= = =


Water level at section 1-1 2 252.72 252.50 2 0.1122

Water level at section 2-2

Length of contraction transition 2 11.70 2 5.85 m

Hydraulic 5




Hydraulic 6

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C

=

y

=

y1 x12

0.112

=

=

34.223

0.00328 x2

66591175.xls

0.00328

(equation of water surface profile in contraction transition)

The details of the contraction transition have been worked out in Table 1 (b) Expansion transition w.s.profile

4

3

R.L. y1 =

252.10

0.065

R.L. 25 1. 1.97 x 1=

8.78 17.55

4

3

Expansion transition y1

= = =

x1

= = =

Water level at section 4-4 -

Water level at section 3-3 2

252.10

2

251.97

0.0654 m Length of expansion transition 2 17.55 2 8.78 m

Hence, C

=

y

=

y1 2 1

x

0.00085

=

x2

0.07 77

=

0.00085

(equation of water surface profile in expansion transition )

The details of expansion transition have been worked out in Table 1


Hydraulic 7



66591175.xls

Table 1 water Distance

2

y=cx

surface

Elevation Velocity head (hV) of

elevation 1

2

T.E.L.

(4) - (3)

m

m

m

3

4

5

From section 1-1 to 2-2

Velocity V= √2ghV

side

Area A=

slope 's'

Q/V

Bed Level

Depth(D)

Bed

Col.(3)

width

-Col(9) m 6

7

B = A/D -sD

8

9

10 10

11

CONTRACTION TRANSITION

0

0.0000

252.720

252.761

0.041

0.901

1.500 :1

44.392

250.62

2.10

18.00

3.0

0.0295

252.690

252.752

0.062

1.099

1.115 :1

36.406

250.34

2.35

12.86

5.85

0.1122

252.608

252.742

0.135

1.627

0.750 :1

24.593

250.06

2.55

7.73

8.7

0.0295

252.525

252.733

0.208

2.021

0.385 :1

19.794

249.78

2.75

6.30

11.7

0.0000

252.495

252.724

0.228

2.116

0.00 :1

18.900

249.50

3.00

6.30

248.969

From section 3-3 to 4-4

EXPANSION TRANSITION

0

0.0000

251.969

252.197

0.228

2.116

0 :1

18.900

3.00

6.30

3

0.0076

251.977

252.188

0.211

2.035

0.256 :1

19.656

249.145

2.83

6.30

6

0.0306

252.000

252.178

0.179

1.872

0.513 :1

21.372

249.322

2.68

6.61

8.78

0.0654

252.035

252.169

0.135

1.627

0.750 :1

24.593

249.485

2.55

7.73

11.55

0.0306

252.069

252.161

0.091

1.337

0.987 :1

29.913

249.648

2.42

9.96

14.55

0.0076

252.092

252.151

0.059

1.072

1.244 :1 :1

37.300

249.824

2.27

13.62

17.55

0.0000

252.100

252.141

0.041

0.901

1.500 :1

44.392

250.00

2.10

18.00

(5) Invert level Bed level of drain = Provi ovide

0.30

251.80 m

m thick conc oncrete slab and

0.60

m thick earth fill over the slab

Invert level of the concrete

= 251.80 - ( 0.6 + 0.3 + 2.5 ) = 248.40 m Invert level at the entrance and exit of the barrel shall be the same as the bed levels already worked out at sections 2-2 and 3-3 respectively.

Thus the invert level at the entry = The invert level at the exit =

249.495 m 248.969 m

The The inver nvertt level evel of the the barr barrel el woul ould be kept kept at 248. 248.40 40 m in a lengt ength h of 44.5 44.5 m (under base of drain) after which it would meet the respective bed levels at the entrance and exit, so as to obtain a slope of about 1in 15 in the barrel at either side. Thus, Length of barrel upstream = 16.00 m Length of barrel downstream = 8.00 m The length of the pucca floor on either end should be adequate to provide safe hydraulic gradient and its thickness sufficient to counterbalance the total uplift pressure by gravity. The barrel shall be made of reinforced concrete box construction and its structural design is given subsequently.


Hydraulic 8



66591175.xls

(6) Pucca Floor Provide pucca floor in half the transition length in the upstream and 3/4 th the length of expansion transition in the downstream. Length of pucca floor upstream = 1/2 X 11.7 = 5.85 m say 6.00 m Length of pucca floor downstream = 3/4 X 17.55 = 13.16 m = say 13.00 m The floor shall be subjected to static uplift and seepage head; it is maximum when high flood is passing through the drain and there is no flow in the barrel. The seepage head would be calculated by Bligh's theory. (7) Uplift pressures on the barrel floor and pucca floor (a) Static pressure At bottom of barrel floor Deepest est invert level of the barrel = 248 248.40 m The thickness of the barrel is = 0.30 m The bottom level of the barrel floor = 248.10 m Assu Assumi ming ng the the subsub-so soil il wate waterr lev level el upto upto the the bed bed leve levell i.e i.e.a .att R.L R.L.. static head = 250.00 248.10 = 1.90 m

250. 250.00 00 m, the the max maxim imum um

At the downstream end of barrel Floor level at d/s end of barrel = 248.969 m Assuming floor thickness at this point 2.00 m, The bottom level of pucca floor = 248.969 2.00 = 246.969 m Hence, Static head = 250.00 246.969 = 3.031 m At the upstream end of barrel Floor level at u/s end of barrel = 249.495 m Assuming floor thickness at this point 1.50 m, The bottom level of pucca floor = 249.495 1.50 = 247.995 m Hence, Static head = 250.62 247.995 = 2.624 m (b) Seepage head The seepage head will be maximum when the drain is running full and there is no flow in the canal. Thus total seepage head = = H.F.L. in the drain Bed level of cana anal


Hydraulic 9



= =


253.25 3.25 m

66591175.xls

250.00

Hydraulic 10



66591175.xls

At bottom of barrel floor The residual seepage head at point 'a' in the centre of the first barrel has been calculated by Bligh's theory. The seepage line would follow the path indicated by the line x a b y. Its total length (neglecting floor depression or thickness) is the sum of the following (i) (ii) (iii)

Half the barrel span = Length of barrel in indicated portion = Length of pucca floor =

Thus Thus tota totall cree creep p lengt length h= barreel= 1.5 m

1.5 m 8.00 m 13.00 m

22.50 22.50 m and and cree creep p lengt length h upto upto poin pointt 'a' 'a' i.e. i.e. centre centre of fir first st c.c.floor

c.c.cutoff 13.00

8

b

a

y

1.5

x R.C.C.Barrel

Barrel Plan Residual seepage head point 'a' Thus total uplift in the barrel

= =

= say

3.033 m 1.90 + 4.93 m 4.93 t/m2

3.033

At the downstream end of barrel floor total creep length upto the end of barrel floor i.e. at point b = 1.5 = 9.5 Hence , Residual seepage head at this point = 1.88

+ m

8.0

m

Thus total uplift

= Static uplift + residual seepage head = 3.031 + 1.88 = 4.909 m 4.909 The floor thickness required (sp.gr.=2.22) = ----------- = 2.22 Say

2.20

m

Provi ovide

0.90

m at the end of floor

2.20


m thick c.c.floor oor d/s and reduce uce it to thicknes ness

Hydraulic 11

2.211 m



66591175.xls

At the upstream end of barrel floor total creep length upto the end of barrel floor = 1.5 + = 17.5 m Hence , Residual seepage head at this point =

16.00

0.83

m

Thus total uplift

= Static uplift + residual seepage head = 2.624 + 0.83 = 3.454 m 3.454 The floor thickness required (sp.gr.=2.22) = ----------- = 2.22 Say

Provi ovide

1.60

m thick c.c.floor oor u/s and reduce uce it to thicknes ness

1.556

m

1.60

m

0.70

m at the end of floor

**********************


Hydraulic 12


Office of Director Dam I.D.R.,Jaipur

N I A R D

TRANSITION WING

4.28

TRANSITION WING

4.28

B

0.30 M THICK

R.C.C. BARRELS

A

CANAL

66591175.xls

A

3.00

0 0 . 8 1

0 0 . 8 1

3.00

4.28

16.00

B

44.50

8.00

4.28



11.7

68.50

17.55

PLAN 0.60 TH. EARTH EARTH FILL TOP OF WING WALL

TOP OF WING WALL

R.L. R.L. 253.47 253.47

R.L. 254.00

U/S F.S.L. F.S.L. 252.72 252.72

254.00

H.F.L. 253.25

R.L. 252.85 D/S F. F.S.L.

252.10

CANAL U/ S BED R. L. L.

250. 62 62

249.50

2.50

D/ S R. L. L.

248.97

25 0. 0. 00 00

248.40

U/S TOE WALL

U/S CUT OFF

DRY BRICK PITCHING

5.70

C.C. BLOCK

6.00

16.00

LEAN CONCRETE

C.C. BLOCK

44.50

11.7

TOP OF BANK

254.00 253.25

D/S TOE WALL

4.55

D.B. PITCHING

17.55

SECTION AT A-A

251.80

1 2 3 4 5

TOP OF BARREL ROOF

R.L. 251.20 251.20 3.10

R.L. 248.40 248.40

D/S CUT OFF

13.00

8.00

68.50

H.F.L. OF DRAIN BED LEVEL OF DRAIN

0.30 TH. R.C.C. BARREL

6.90

DETAILS OF PROTECTION WORKS U/S TOE WALL 0.40 X 0.80 U/S CUT OFF 0.50 X 1.00 C.C. BLOCK 0.50 X 0.50 D/S CUT OFF 0.50 X 1.50 D/S TOE WALL 0.40 X 1.00

Drawing 13

Program by - Sunil K Goyal

Checked by- P P Pareek

Office of Directo r Dam I.D.R.,Jaipur

66591175.xls

SECTION AT B-B

6 LEAN CONCRETE 7 D.B.PITCHING

0.15 M THICK 0.40 M THICK

DETAILS OF TRANSITION WINGS

TRANSITION WING

TRANSITION WING

4.28

0 0 . 8 1

4.28

6 8 . 2 1

3 7 . 7

0 3 . 6

0 3 . 6

0 3 . 6

1 6 . 6

3 7 . 7

6 9 . 9

2 6 . 3 1

0 0 . 8 1

6.00 3.00 5.85 4.28

8.70 11.70


8.78 11.55 14.55 17.55


DETAILS OF PUCCA FLOOR

4.28

Office of Directo r Dam I.D.R.,Jaipur

66591175.xls

SECTION AT B-B

6 LEAN CONCRETE 7 D.B.PITCHING

0.15 M THICK 0.40 M THICK

DETAILS OF TRANSITION WINGS

TRANSITION WING

TRANSITION WING

4.28

0 0 . 8 1

4.28

6 8 . 2 1

3 7 . 7

0 3 . 6

0 3 . 6

0 3 . 6

1 6 . 6

3 7 . 7

6 9 . 9

2 6 . 3 1

0 0 . 8 1

6.00 3.00 5.85

8.78 11.55 14.55 17.55

8.70 11.70

4.28


4.28


DETAILS OF PUCCA FLOOR

0.70

5 1 . 1

0 6 . 1

0 2 . 2

2.00 4.00 6.00

0 7 . 1

3.25

0.90

0 3 . 1

3. 3.25

3. 3.25

3. 3.25

13.00

U/S PUCCA FLOOR


D/S PUCCA FLOOR

Drawing 14



66591175.xls


66591175.xls

Drawing 15




66591175.xls

STRUCURAL DESIGN OF A CANAL SYPHON

NAME OF PROJECT :


DESIGN DATA :

1 UNIT UNIT WEIG WEIGHT HT OF OF DRY DRY EARTH EARTH

1.60

t/m3

2 UNIT WEIGHT WEIGHT OF OF SATURA SATURATED TED EARTH EARTH

2.00

t/m3

3 UNIT WEIGHT WEIGHT OF OF SUBMER SUBMERGED GED EARTH EARTH

1.00

t/m3

4 UNIT UNIT WEIGH WEIGHT T OF CONC CONCRE RETE TE

2.40

t/m3

5 ANGLE OF INTERNAL FRICTION (

φ)

30

Degree


66591175.xls

STRUCURAL DESIGN OF A CANAL SYPHON

NAME OF PROJECT :


DESIGN DATA :

1 UNIT UNIT WEIG WEIGHT HT OF OF DRY DRY EARTH EARTH

1.60

t/m3

2 UNIT WEIGHT WEIGHT OF OF SATURA SATURATED TED EARTH EARTH

2.00

t/m3

3 UNIT WEIGHT WEIGHT OF OF SUBMER SUBMERGED GED EARTH EARTH

1.00

t/m3

4 UNIT UNIT WEIGH WEIGHT T OF CONC CONCRE RETE TE

2.40

t/m3

5 ANGLE OF INTERNAL FRICTION (

φ)

30

6 GRADE OF STEEL 7 GRADE OF CONCRETE 6 DIAMETER OF REINF. BARS

Main Dist

7 NUMBER OF BARRELS

Fe

415

M

20

Degree

16 12

Φ Φ

2

Nos.

8 WIDTH OF EACH BARREL

3.00

m

9 HEIGHT OF EACH BARREL

2.50

m

10 THICKNESS OF BARREL

0.30

m

11 BANK LEVEL

254.00

m

11 DRAIN H.F.L.

253.25

m

12 LEVEL AT TOP OF BARREL

251.20

M

13 UPLIFT AT BASE OF BARREL


4.93

Structural 16

Checked by - P P Pareek

t/m2


66591175.xls

(1) Critical section of of the the barrel The barrel shall be subjected to maximum loading under the bank at the lowest possible level of the barrel as indicated below in the following section:Bank level

254.00 m

Saturati on on l in ine

253.25 m R.L. 251.20 m

2.50 R.L.

248.40 m

R.L.

248.10 m

6.90

(2) Design Design feature features s Following cosiderations have been made in the design of barrels : (i) (i) Bott Bottom om slab slab : This This desi design gn is for for upl uplif iftt pre press ssur ure e and and reac reacti tion on from from soil soil resu result ltin ing g fro from m the loading on the foundations. Theoretically, the soil reaction is not uniform but for simplification it is assumed uniform. (ii) (ii) side side walls walls : Side Side wall walls s would would be be tested tested in the the follo followi wing ng two two criti critical cal condit condition ions s (a) High flood in the drain while barrels are empty (b) No water in the drain while barrels are full (iii) (iii) Partit Partition ion walls walls : The part partiti ition on wall walls s are are subjec subjected ted to to equal equal pres pressur sures es on either either side side,, and therefore,no reinforcement is required. Nominal reinforcement is, however, provided to take care of contingency arising due to unequal pressures resulting from chocking up of any of the barrels. (iv) (iv) Top Top slab slab : The The loa loads ds con consi side dere red d for for des desig ign n of top top slab slab are are : (a) Earth load, (b) Weight of water below saturation line As there is no roadway along the drain, no live load due to traffic shall be considered. (3) (3) Desi Design gn As the barrels are rigidly joined, they should be designed as a continuous structure. Hardy Cross method of moment distribution shall be used for design. The effective length of horizontal member = 3.30 m The effective length of vertical member = 2.80 m Distribution factors At joint A For member AB

=

For member AD

=


2.8

2.8 +

3.3

2.8

3.3 +

3.3

Structural 17

=

0.46

=

0.54




Structural 18

66591175.xls



66591175.xls

At joint D For member DA

=

For member DC

=

2.8

3.3 +

3.3

2.8

2.8 +

3.3

=

0.54

=

0.46

(i) (i) Dead Dead loads loads Consider one meter length of barrel Depth of dry earth over barrel = Depth of saturated earth =

254.00 253.25

Weight of dry and saturard earth = = Weight of top slab

=

0.75 X 5.3

1.60 t/m2

0.30 X

2.40

Weight on the top slab including its own weight = = Weight of the barrels per metre of length =( 4 X 3.3 + 3 = 15.55 t Total dead load/m length of barrels Uplift/m length

=

4.93 X

X

Pressure acting on the base slab

5.3 + 6.02 t/m2

2.8

)

=

52.12 18.08 t

=

2.62

=

0.75 m 2.05 m 2.00

0.72 t/m2 0.72

X

0.30 X

+

-

5.3

2.40

X

6.90

34.04

t/m2

= Soil reaction + = 2.62 + 2 = 7.55 t/m

Net upward pressure on the base slab =

= =

2.05 X

=

15.55 52.12 t 34.04 t

18.08 6.90

253.25 251.20

+

= = 6.90 =

Net vertical load acting on foundation =

Pressure on foundation soil =

-

7.55 2 6.83 t/m

uplift 4.93

0.72

(ii) (ii) Earth Earth pressu pressure re The earth pressure shall comprise of the following : (a) dry eart arth pressure above saturati ation line from R.L. (b) saturated earth pressure from R.L.


Structural 19

253. 53.25 253.25

to to

254.0 4.00 248.25



Corresponding to φ = 30 degree , The The pres pressu sure re at A= Surc Surcha harg rge e due due to dry dry eart earth h = Cp X wd X 0.75

Pressure at D

=

1/3

X

=

3.33 t/m2

= = =

3.33 + 3.33 + 7.07 t/m2

1.60 X

Cp

X 1/3 X

66591175.xls

Cp

= 1/3 Surc Surchar harge ge due to satu satura rate ted d eart earth h Cp X ws X 2.20

+ + 0.75

+

ws

X X

1.00

+ w X 2.20 1/3 X 1.0 X + 1 X 2.20

2.20

2.8 + 2.8 +

2.8 2.8

w 1

X X

Loads acting on different members are shown below : 6.02 t/m2 3.33 t/m2

3.33 t/m2

A

B

E

3.30

D

3.30

0 8 . 2

C D

2

7.07 t/m

F 7.07 t/m2

6.83 t/m2

(iii) (iii) Fixing Fixing moments moments (i)

On span AB

=

wl2 12

6.02 =

12

=

(ii)

On span CD

=

wl2 12

5.46 t-m 6.83

3.3 2

X

=

12

= (iii (iii))

3.3 2

X

6.20 t-m

On span span AD AD fix fixed ed end end mom momen ents ts in the the wal walll at at each each end due due to rect rectan angul gular ar porti portion on

=

wl2 12 12

3.33 = =

2.8 2

X 12

2.178 t-m

Fixed end moments due to triangular portion 3.73 X


MAD

= =

30 0.98 t-m

MDA

=

3.73 X 20

2.8 2

2.8 2

Structural 20



=


66591175.xls

1.46 t-m

Structural 21



66591175.xls

Total fixed end moments at A

= =

2.178 + 3.15 t-m

0.976

Total fixed end moments at D

= =

2.178 + 3.64 t-m

1.46

(iv) Distribut Distribution ion of moments moments Joints Distribution factors Fixed end moments Balance Carry over Balance Carry over Balance Carry over Balance Total

C

D 0.46

-6.20

B

0.54

0.46

6.20

-3.64

3.15

-5.46

-1.18

1.25 -0.69 0.37 -0.17 0.09 -0.05 0.03

1.06

-0.02

-1.39 0.62 -0.34 0.19 -0.10 0.05 -0.02

4.63

-4.63

3.98

-3.98

-0.59 -0.29 -0.14 -0.09 -0.04

-6.98

A 0.54

5.46

0.53 0.32 0.16 0.08 0.04 0.02 6.19

(v) Net moments moments at centre centre and face Span AB 6.02 X 3.3 Sagging moments at face = ------------------2 = Fixing moments at face=

X

-

1.42 t-m 3.98 +

3.15 ( 3.3

=

6.09 t-m

Net fixing moments at face

= =

6.09 4.67 t-m

Sagging moments at centre

=

6.02 X

=

8 8.19 t-m

Fixing moments at centre

= =

Net sagging moments at centre


0.15

6.02 X 0.15 2 ----------------------------2

= =

3.98 + 2 5.09 t-m 8.195 3.107 tt-m

6.19 -

3.98

)

1.422

3.3 2

6.19

5.088

Structural 22




Structural 23

66591175.xls



66591175.xls

Span CD 6.83 X 3. 3.3 Sagging moments at face = -------------------2 =

X

6.83 X 0.15 2 ---------------------------2

0.15 -

1.61 t-m

Fixing moments at face=

=

3.15 ( 3.3

4.63 4.63 +

6.98 -

4.63

)

6.87 t-m


= =

6.87 5.25 t-m

Sagging moments at centre

=

6.83 X

1.61

3.3 2 8

= Fixing moments at centre

9.3 t-m

=

6.98 +

4.63 2

=

5.8 t-m


= =

9.303 3.498 t-m

-

5.804

Span AD (a) (a)

Due Due to rect rectan angu gula larr port portio ion n = =

(a)

3.33 X

2.8 2

X

0.15

X

0.15

3.33

-

0.15 2

X 2

0.66 t-m

Due to trian riangu gullar por portion tion =

3.73 X 2

2.8

X

= 0.26 t-m Total sagging moments at face

Fixing moments at face

= = = =


1 3

3.98 +

-

0.2

0.15 2

0.662 + 0.92 t-m 2.65 2.8

X

X

0.261

(

4.63

-

3.98 )

4.6 t-m

Structural 24

0.05




Structural 25

66591175.xls




= =

66591175.xls

4.6 - 0.92 3.67 t-m

Sagging moments at centre (a)

Due to rectangular portion

=

3.33

2.80 2

X 8

= (b)

Due to triangular portion = =

3.27

t-m

3.73 X 2.80 2 1.87 t-m

X

Total sagging moments at centre

Fixing moments at centre

=


= =

4.63 + 2

2.8

X

3.27 + 5.14 t-m

1 7.81

1.87

3.98

=

4.31 t-m

= =

5.14 0.83 t-m

4.31

The net moments at face and centre of the different spans are tabulated below : MOMENTS

Span

At face 4.67 t-m (hogging) 5.25 t-m (hogging) 3.67 t-m (hogging)

AB CD AD

3.11 3.50 0.83

At centre t-m (sagging) t-m (sagging) t-m (sagging)

(vi) Thickness of members The maximum moment in the barrels is Fo r M

σcbc

5.25 tt-m

20 grade concrete and steel of Fe = σst = 70 Kg/cm2

415 1500.00 Kg/cm2

m = 13 k = 0.378 j = 0.874 Q = 11.552 The minimum effective thickness (d) required for bending moment M 5.25 X d = = bQ 100 X = 21.33 cm Adopt overall thickness of all the members = Then effective thickness


Structural 26

=

105 11.55

30.0 cm 25.20 cm



(clear cover =


Structural 27

66591175.xls

4.0

cm )



66591175.xls

The reinforcement required at various points is given below : (vii)

Reinforcement

Span AB & BE Moments in t-m At face

Reinforcement required At

4.67 t-m (hogging) Prov Proviide

At centre

3.11 t-m (sagging) Prov Proviide

14.13 Cm2 14.0 14.0 cm c/c c/c

= 16 mm bar bars @ At =

9.40 Cm2 21.0 21.0 cm c/c c/c

16 mm bar bars @

Span CD & CF Moments in t-m At face



At centre


15.90 Cm2 12.0 12.0 cm c/c c/c


10.59 Cm2 18.0 18.0 cm c/c c/c

16 mm bar bars @

Span AD & EF Moments in t-m At face



At centre


11.12 Cm2 18.0 18.0 cm c/c c/c


2.52 Cm2 25.0 25.0 cm c/c c/c

16 mm bar bars @

Nominal steel shall also be provided on the outer face of the walls for the condition when there is no water in the drain and barrels are running full. The details of reinforcement are shown below 16 mm 16 mm

C.C. C.C. M - 20

φ @

16 mm

φ @ 21.0 cm c/c

16 mm

φ @ 25.0 cm c/c

16 mm

φ @ 18.0 cm c/c

16 mm φ @ 16 mm

0.30

φ @

14.0

cm c/c

14.0 cm c/c 12 mm

φ @

25.0

cm c/c

12 mm

φ @

25.0

cm c/c

12.0 cm cm c/c

clear cover =

4.00

cm

φ @ 18.0 cm c/c

3.00 m

0.30

3.00

0.30

DETAILS OF REINFORCEMENT IN SYPHON BARRELS


Structural 28



66591175.xls

*************


Structural 29


Canal Syphon Programme

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