Annex 1 a- B157 Hydrorology Calculations

8/2/2019 Annex 1 a- B157 Hydrorology Calculations

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Annex 1 A _B157- Mathugama- Aluthgama Road- Summary of Bridge Openings

BRIDGE

Chainage

BridgeNo

PROPO

SEDWIDTH(m)

PdrposedMinimumHeight

AVAILABLEHEIGHT(m)

Measu

redwaterdepth

Opens

pace(uptodeckbott

AvailableWIDTH(m)

Remar

ks

31/3 No Change-5.2m ** 3.00 0.60 2.40 5.20

30+750 31/4Increase height to 1.8m -

Spam 3.15m no change**

1.10 0.20 0.90 3.15

Height to be increased to

1.8m

34/2 No Change - 9m 2.75 1.70 0.30 1.40 9.00

34/3 No Change - 3.4m ** 1.80 0.80 1.00 3.40

34/4 No Change - 3m ** 1.80 0.80 1.00 3.00

35/4 No Change 4.8 ** 2.30 0.70 1.60 4.90

35/5No Change-4.3m

2.002.20 1.10 1.10 4.20

Additional opening allocated

to culverts

Welipenna

Ganga39/5

No Change 18.3**

10.30 1.90 8.40 18.00

40/1 No Change 3m ** 1.85 0.30 1.55 3.00

NewAdd 12m NEW

3.00

Kohiawala

Galamatte RB42+000 New

Add 40m NEW

2.15 Revised further based on new

verticle alignment

Galamatta 42+550 43/4 No Change 45.8m 4.00 4.80 1.90 2.90 46.00

42+814 43/5 Replace 20m 2.00 2.50 0.90 1.60 3.00

42+826 43/6 Replace 20m 2.00 2.00 0.80 1.20

42+978 43/7 Replace 20m 2.00 0.80 0.30 0.50 1.30

43+069 44/1 Replace 6.1m 2.00 1.60 0.40 1.20 1.60

43+678 44/3 Replace 15m 2.00 2.40 1.50 0.90 7.00

43+758 44/4 Replace 6m 2.00 1.20 0.30 0.90 1.60

43+795 44/5 Replace 6m 2.00 0.00 dia.0.645+650 46/2 Replace 6m 2.00 1.00 0.20 0.80 dia.0.945+730 46/3 Replace 6m 2.00 1.50 1.50 0.00 6.00

47+048 48/1 Replace 4m 2.00 0.95 0.25 0.70 2.20

47+400 48/2 Replace 4m 2.00 1.10 0.20 0.90 dia.0.947+865 48/3 Replace 4m 2.00 2.00 1.00 1.00 dia.0.9

49+068 50/1 No Change 8.9m 2.15 1.60 0.70 0.90 9.00

49+308 50/2Replace 13m

2.15 0.90 0.30 0.60 0.60Additional opening added to

50/2

52+111 53/2 No change 3m ** 1.30 0.30 1.00 3.00

Galamatta LB

Feasibility Study and Detailed Design Review NHSP - Southern Expressway Link Roads

Hydrology Repo

Annex 1 A - Page


2/8

Hydrauic Computations for bridges in B157- Mathugama- Aluthgama Road

BRIDGE

Number

CATCHMENTAREA

-

sqkm

CATCHMENTAREA(ha)(A

)

LENGTHOFEFFECTIVE

WATERCOURSE-ACADUNITS

LENGTHOFEFFECTIVE

WATERCOURSE(m)L

SLOPE(%)

FLOW

VELOCITY(ft/sec)

TIMEOFCONCENTRATION

Tc=l/60v+15(min)[Ponrajah

's

Formula]

RETURNPERIOD(yr.)

RAINFALLINTENSITY(mm/h

r)

RUNOFFCOEFFICIENT

DISCHARGEQ=CIA/360

(cumecs)

ExistingBridgeWid

th

(m)

Nearbyculvertwidth

(m)

Proposedaddiotion

al

structurewidth(m)

BW(m)-CLEARSPAN

31/3 2.20 220.00 2.70 1695 0.1000 1.5 76.79 100.00 108.95 0.30 19.97 5.20 3.15 0.00 8.35

31/4

34/2 1516.00 2.70 4145 0.0100 1.5 166.09 100.00 62.62 0.30 79.11 9.00 6.40 4.00 19.40

34/3

34/4

35/4 2.39

35/5 9.70 970.00 1.41 4703 0.1000 1.5 186.44 100.00 57.64 0.30 46.59 4.30 4.80 2.00 11.10

35/6 2.00

Welipenna

Gamga39/4 59.60 5960.00 1.60 12265 0.0500 1.5 462.11 100.00 30.08 0.30 149.41 18.30 1.60 10.00 29.90

40/1 2.74

Kohiawala

Galamatte

RB

New 27.00

Galamatta 43/4 147.55 45.80 0.00 0.00 45.80

Galamatta LB 43/5 2.56 20.00

43/6 0.88 20.00

43/7 20.00

44/1 6.00

44/2 Individual Culvert

44/3 18.62 1862.00 0.83 8374 0.0100 1.5 320.26 100.00 39.12 0.30 60.69 0.00 6.00 18.00 24.00

44/4 6.00

44/5 5.00 6.00








3/8

Cross Section at U/S Paddy Field

Segment Length Ground Level 100yr Flood Level

Water Height Water Area

0.00 1.4 3.30

18.00 0.5 3.30 1.90 42.30

8.70 0.56 3.30 2.80 24.10

12.70 0.5 3.30 2.74 35.1810.00 0.6 3.30 2.80 27.50

10.00 0.57 3.30 2.70 27.15

13.80 0.55 3.30 2.73 37.81

9.00 0.52 3.30 2.75 24.89

6.80 0.39 3.30 2.78 19.35

6.00 0.39 3.30 2.91 17.46

9.00 0.79 3.30 2.91 24.39

11.50 1.2 3.30 2.51 26.51

18.00 3.3 3.30 2.10 18.90

7.40 4.5 3.30 0.00

-1.20

140.90

Total Area===> 325.53

Velocity===>> 0.30

(Discharge)Q 97.66

Latest Road Design Level

Level m MSL Chainage m

2.315 42000.000,

2.317 42003.000,2.328 42008.078,

2.396 42020.000,

2.431 42023.933,

2.565 42035.227,

2.6 42037.653,

2.637 42040.000,

2.734 42045.653,

2.817 42050.000,

3.037 42060.000,

3.124 42063.508,

3.277 42070.000,

3.464 42080.000,

3.592 42090.000,

3.628 42094.105,

3.652 42097.994,

3.661 42100.000,

3.668 42102.105,

3.673 42104.530,

3.675 42106.812,

3.624 42120.000,

3.493 42131.680,

3.481 42132.480,

3.368 42140.000,

3.172 42153.000,

3.105


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ADDITIONAL OPENING FOR 42+000

Cross Section at U/S Paddy FieldSegment

Length

Ground

Level

Embankment

Level Water Height

Water

Area

0.00 1.4 3.10 1.70 38.79

18.00 0.5 3.10 2.60 22.40

8.70 0.56 3.10 2.54 32.70

12.70 0.5 3.10 2.60 25.5510.00 0.6 3.10 2.50 25.20

10.00 0.57 3.10 2.53 35.12

13.80 0.55 3.10 2.55 23.13

9.00 0.52 3.10 2.58 18.02

6.80 0.39 3.10 2.71 16.29

6.00 0.39 3.10 2.71 22.63

9.00 0.79 3.10 2.31 24.26

11.50 1.2 3.10 1.90 15.39

18.00 3.3 3.10 -0.20

7.40 4.5 3.10 -1.40

TOTAL 140.90

Total Area===>>>> 299.491

Velocity===>> 0.3

Q 89.847

This calculates the 100 year Q under embankment level- rest is overflow and do not come to

CALCULATION FOR ADDITIONAL OPENING B157 for KOHILAWALA

Calculation of the Opening Size for Flow Path at "Kohilawala"

Cross Section Area of flow path Kohilawala (A1) 299.5 m2

Assumed velocity(V1) 0.3 m/s

Discharge (Q1= A1xV1) 89.8 m3/s

Assumed velocity at the road section after embanking (V2) 1.08 m/s

Required area at the road section(A2= Q1/V2) 83.2 m2

20 Year Flood Level 2.55

Asumed water height 2.15 ( No Free Bo

Required opening width 38.7


Hydrology Report

Annex 1 A - Page 3


5/8

the proposed opening

rd Alowed)


Hydrology Report

Annex 1 A - Page 3


6/8

XSS of Road for Culvert 43/5 & New Culverts ( Galamatte Bridge 43/4- RB Flood Plain) Calculation of Culvert Opening Sizes

Chainage

From

Galamatte

Flod Plain

42+550km Existing Level

100year

Flood

Level m

MSL

20year

Flood

Level m

MSL

Proposed

Embankm

ent Level

Diff /Fill

Height for

20 Year

Flood Area Q (Welipenna Southern Expressway Bridge) 394 Mike11 study

0 3.123 3.3 2.55 2.55 -0.573 Cross Section Area of flow path through culvert 522.02 m2

20 2.286 3.3 2.55 2.55 0.264 10.2 Assumed velocity(V1) 0.3 m/s

40 1.794 3.3 2.55 2.55 0.756 15.93 Discharge (Q1= A1xV1) 156.606 m3/s60 1.713 3.3 2.55 2.55 0.837 7.9 Assumed velocity at the road section (V2) 1.08 m/s

70 1.807 3.3 2.55 2.55 0.743 15.08 Required area at the road section(A2= Q1/V2) 145.0056 m2

90 1.785 3.3 2.55 2.55 0.765 14.71

110 1.844 3.3 2.55 2.55 0.706 14.08 20 Year Flood Level 2.55

130 1.848 3.3 2.55 2.55 0.702 13.93

150 1.859 3.3 2.55 2.55 0.691 15.15 Asumed water height 2.15170 1.726 3.3 2.55 2.55 0.824 19.31 Required opening width 67.44444

190 1.443 3.3 2.55 2.55 1.107 23.21

210 1.336 3.3 2.55 2.55 1.214 25.34

230 1.230 3.3 2.55 2.55 1.320 24.98

250 1.372 3.3 2.55 2.55 1.178 21.92

270 1.536 3.3 2.55 2.55 1.014 18.14

290 1.750 3.3 2.55 2.55 0.800 15.23

310 1.827 3.3 2.55 2.55 0.723 15.36

330 1.737 3.3 2.55 2.55 0.813 19.19

350 1.444 3.3 2.55 2.55 1.106 22.18370 1.438 3.3 2.55 2.55 1.112 20.96

390 1.566 3.3 2.55 2.55 0.984 18.81

410 1.653 3.3 2.55 2.55 0.897 17.64

430 1.683 3.3 2.55 2.55 0.867 19.05

450 1.512 3.3 2.55 2.55 1.038 19.37

470 1.651 3.3 2.55 2.55 0.899 15.43

490 1.906 3.3 2.55 2.55 0.644 10.68

510 2.126 3.3 2.55 2.55 0.424 8.51

530 2.123 3.3 2.55 2.55 0.427 9.63

550 2.014 3.3 2.55 2.55 0.536 11.04

570 1.982 3.3 2.55 2.55 0.568 11.26

590 1.992 3.3 2.55 2.55 0.558 11.58

610 1.950 3.3 2.55 2.55 0.600 12.57

630 1.893 3.3 2.55 2.55 0.657 12.32

650 1.975 3.3 2.55 2.55 0.575 8.4670 2.285 3.3 2.55 2.55 0.265 2.93

690 2.522 3.3 2.55 2.55 0.028

710 2.961 3.3 2.55 2.55 -0.411

TOTAL=>> 522.02


Hyd

Anne


7/8

SUMMARY OF OPENING DETAILS FROM 42+000-43+069

( Galamatte Bridge Flood Plain - Welipenna River)

Culvert Chainage SLLRDC LS CHAINAGE

LB Kohilawala 42+000 42 2700

Galamatte 43/4 Galamatte 42+550 42.55 2150

43/5 42+814.609 42.814 1886

43/6 42+826.168 42.826 1874

43/7 42+978.780 42.978 1722

44/1 43+069.199 43.069 163144/2 43+301.628 43.301 1399

44/3 43+678.124 43.678 1022

44/4 43+758.856 43.758 942

44/5 43+795.695 43.795 905

44/6 43+860.556 43.86 840

45/1 44+035.703 44.035 665

45/2 44+145.834 44.145 555

Culverts on Galamatta RB Flood Plain

Galamatte LB Flood Plain

SUMMARY OF OPENINGS

Gaamatte LB- Kohilawala 40 m

Galamatte Bridge 45.8 mGalamatte RB 67 m

TOTAL 152.8 m

Southern Expressway -Welipenna 150 m

RB


Hydrology Report

Annex 1 A - Page 5


8/8Feasibility Study and Detailed Design Review NHSP - Southern Expressway Link Roads

Hydrology Report

Annex 1 A - Page 6

Documents

Annex 1 a- B157 Hydrorology Calculations