0403-DRAINAGE AND BRIDGE DESIGN .pdf

7/30/2019 0403-DRAINAGE AND BRIDGE DESIGN .pdf

1/25


2/25

Consultancy Services for the Feasibility Study for the Upgrading

to Paved (Bitumen) Standard of Muyembe-Moroto Road

4. PRELIMINARY DESIGNFEASIBILITY STUDY REPORT (19/03/09) 4.3. DRAINAGE AND BRIDGE

4.3- DRAINAGE AND BRIDGES


3/25


4/25


5/25


6/25




TABLE OF CONTENTS

1. DRAINAGE AND BRIDGES DESIGN ___________________________________________ 11.1. General Drainage System 11.2. Bridges 6


7/25


8/25


9/25




- 1 -

1. DRAINAGE AND BRIDGES DESIGN

The first objective was indentifying drainage requirements for natural streams crossing the Project

Alignment, for this purpose a Hydrological Study was carried out. They were identified seventy one (71

No) watersheds along the road from Muyembe to Moroto, also the drainage structures within each of

the watersheds:

- General Drainage System: culverts and box culverts

- Bridges

Based on the structural conditions, the assessment of flood marks and using 25 and 50 year Peak

discharges for the general system drainage and bridges respectively, their combined capacities weredeterminate together and depending of each case remedial actions have been proposed.

1.1. General Drainage System

We have defined two types of drainage typologies:

- Existing drainage structures: Most of the hydrological culverts capacity is obsolete, for this

purpose the new culverts (with more diameters) have been defined in order to have a correctly

hydrological operation. In the other cases, where existing hydrological capacity culverts is

enough, it is recommended retain it but they have to be elongated to suit the proposed width of

the new road alignment. Consequently headwalls and base slab of one or both drainage

structures will be redone. In these cases retain and clean works are necessary.

- New drainage structures: As consequence of the future horizontal alignment, new drainage

culverts will be necessary. Sometimes will be replaced the existing drainage culverts following

the previous reasoning, but other times there will be new drainage requirements for natural

streams that cross the future road.

All the remedial actions are summarized in the following tables:


10/25




- 2 -

Proposed Remedial Actions for Culverts

New To lengthen Comment

0+000 BC 1400X500 BC 1400X500

traighten pstream

Bend to prevent

pooling at Road

Crossin

2,4 18 It at t imes f loods due to the bend upstream

0+900 CP 1 600 Armco 900 Completely blocked

1+200 CP 1 600 Armco 900 Half silted with with Headwall and Wingwalls cracked


1+500 CP 2 600 2 Armco 900 Culvert is half way silted

2+200 CP 2 600 2 Armco 900 Culvert is half way silted

2+250 CP 2 900 CP 2 900 Headwall is broken and culvert gets flooded when it rains ( At R.

i i2+450 CP 1 600 Armco 900 Culvert is half way silted

2+500 CP 1 600 Armco 900 Culvert is half way silted and down stream Headwall is damaged

2+900 CP 1 600 Armco 900 Half silted with with Headwall and Wingwalls cracked

3+200 CP 1 600 Armco 900 Both upstream & down stream Wingwalls and Headwall damaged

3+500 CP 1 600 Armco 900 Culvert is fully silted

3+800 Required Culvert box culvert 1x1 Completely covered with soil

4+800 CP 1 600 Armco 900 Fully silted

5+570 Cipi Bridge Cipi Bridge

6+120 CP 1 600 Armco 900 Fully silted

6+570 CP 1 600 Armco 900 Completely blocked, Headwall & Wingwalls damaged

6+870 CP 1 600 Armco 900 Completely blocked, Headwall & Wingwalls damaged


7+370 CP 1 600 2 Armco 900 Completely blocked







9+670 CP 1 600 2 Armco 900 Culvert half way silted


10+050 Cheptui Bridge Cheptui Bridge




11+200 J esebere Bridge J esebere Bridge

11+400 CP 1 600 2 Armco 900 Culvert half way blocked & both Headwall & Wingwalls broken

11+600 CP 1 600 2 Armco 900 Culvert half way blocked & both Headwall & Wingwalls broken







14+650 CP 2 600 2 Armco 900 Completely blocked with head and Wingwalls cracked

15+650 CP 2 600 2 Armco 900 Completely blocked with head and Wingwalls broken

16+400 CP 2 600 2 Armco 900 Completely blocked with head and Wingwalls broken

17+350 CP 1 900 CP 1 900 Halfway silted with broken Headwall and Wingwalls.

17+650 CP 1 600 Armco 900 Halfway silted with broken Headwall and Wingwalls.

17+900 CP 1 900 CP 1 900 Retain & Clean Halfway silted



18+210 CP 1 900 CP 1 900 Retain & Clean Halfway silted with broken Headwall and Wingwalls.

18+250 CP 1 900 CP 1 900 Retain & Clean Halfway silted with broken Headwall and Wingwalls.

18+350 CP 1 900 CP 1 900 Retain & Clean Halfway silted

18+700 CP 1 450 Armco 900 Halfway silted



19+300 CP 1 600 Armco 900 Halfway silted with Headwall and Wingwalls existing below groundl l19+350 CP 1 600 Armco 900 Halfway silted with Headwall and Wingwalls existing below ground

l l19+370 CP 1 600 Armco 900 Halfway silted with Headwall and Wingwalls existing below ground

l l19+400 CP 2 600 2 Armco 900 Halfway silted with broken Headwall and Wingwalls.

19+450 CP 1 900 CP 1 900 Retain & Clean

19+550 Armco 1 900 Armco 1 900 Retain & Clean Headwall broken and 2No. Armco vandalised

19+650 CP 1 900 CP 1 900 Retain & Clean OK

19+750 CP 1 600 Armco 900 Headwall and Wingwalls existing below ground level

19+800 CP 1 900 CP 1 900 Retain & Clean OK

20+050 Tabagonyi Bridge Tabagonyi Bridge

19+950 CP 1 900 CP 1 900 Retain & Clean Water flows at full depth of the culvert

20+050 CP 1 900 CP 1 900 Retain & Clean 3No. Culverts damaged at the centre of the road, Headwall & wings are

20+150 CP 1 900 CP 1 900 Retain & Clean Headwall and Wingwalls existing below ground level

20+650 CP 1 900 CP 1 900 Retain & Clean Half filled with silt

21+150 CP 2 600 2 CP 900 Halfway silted with Headwall and Wingwalls existing below ground

l l21+650 CP 1 600 2 Armco 900 Fully silted and blocked

22+100 CP 2 600 2 Armco 900 Halfway silted with broken Headwall and Wingwalls.



24+400 Required Culvert Box culvert 1,5x1,5

25+575 Atari Bridge Atari Bridge


27+330 CP 2 600 3 Armco 900 Fully blocked

27+730 CP 2 600 3 Armco 900 Half silted with the Headwall & Wingwalls cracked.


25 Year

Peak

Flow

Observations

Remedial Action

ExistingChainage

ExistingCapacity

of

Culverts

m3/s

5.9 150

3,9 16

17.5 87

3,5 4

3,3 18

6,3 13

3.3 68

3.3 60

2,0 2

3,3 11

2,6 4

1.3 109

1,3 2

5,2 7


11/25




- 3 -


12/25




- 4 -




32+030 CP 1 900 CP 1 900 Retain & Clean Half silted with the Headwall & Wingwalls cracked.

32+230 CP 1 900 CP 1 900 Retain & Clean The Headwall & Wingwalls cracked.


32+880 Seretyo Bridge Seretyo Bridge

32+950 CP 1 900 CP 1 900 Retain & Clean The Headwall & Wingwalls are broken

33+030 CP 2 600 2 Armco 900 Completely silted and the Headwall & Wingwalls are broken

33+280 CP 2 600 2 Armco 900 Half way silted and the Headwall & Wingwalls are broken

33+430 Required Culvert 2 Armco 900




34+030 CP 2 600 2 Armco 900 The Headwall & Wingwalls are broken

34+080 CP 2 600 2 Armco 900 Half way silted

35+680 CP 1 600 2 Armco 900 Headwall and Wingwalls exist on one side


36+930 CP 1 600 2 Armco 900 The Headwall & Wingwalls have cracks.

37+080 CP 1 600 2 Armco 900 Half silted, head and Wingwalls exist on one side & fully blocked


38+180 CP 2 600 2 Armco 900 Fully blocked and the Headwall & Wingwalls exist on one side & cracked

38+580 CP 2 600 2 Armco 900 Completely silted



42+180 G ilig B ridge G ilig Bridge

42+530 CP 1 600 2 Armco 900 OK



47+780 CP 2 600 CP 2 600 Culvert half way silted

48+080 CP 2 600 4 Armco 900 OK

48+380 CP 1 600 2 Armco 900 OK

53+730 Armco 2 600 4 Armco 900 The Headwall & Wingwalls have cracks.

53+830 Armco 1 900 Armco 1 900 Retain & Clean OK


54+380 Armco 1 900 Armco 1 900 Retain & Clean The Headwall & Wingwalls have cracks.

54+780 CP 1 900 CP 1 900 Retain & Clean Half silted with2No. Pipes crushed at the sides


55+200 CP 1 900 CP 1 900 Retain & Clean Half silted with the Headwall & Wingwalls broken


55+280 CP 4 900 CP 4 900 Retain & Clean Water flows full in the culvert

55+300 CP 1 900 CP 1 900 Retain & Clean Water stagnants in the middle of the culvert

55+730 CP 1 600 2 Armco 900 Completely silted and blocked

56+280 CP 1 600 2 Armco 900 Half filled with silt, Headwall and Wingwalls cracked, watewr stagments

i i l56+480 CP 1 600 2 Armco 900 Half filled with silt and water stagnants in the middle

56+680 CP 1 600 2 Armco 900 Half filled with silt with head & Wingwalls cracked and water stagnants

i i l56+980 CP 1 600 2 Armco 900 Half silted with the Headwall & Wingwalls having cracks

57+080 CP 2 600 4 Armco 900 Completely silted & blocked with the Headwall & Wingwalls cracked

57+330 CP 1 600 2 Armco 900 Completely silted & blocked with the Headwall & Wingwalls having

57+680 CP 1 600 2 Armco 900 Completely silted & blocked with the Headwall & Wingwalls broken

57+980 CP 1 600 2 Armco 900 Half silted and outlet higher than the invert level

58+180 CP 1 600 2 Armco 900 Half silted and outlet higher than the invert level

58+330 CP 1 600 2 Armco 900 Headwall and Wingwalls are broken on downstream side

59+530 CP 1 1200 CP 1 1200 Clean but the outlet higher than the invert level

60+080 CP 3 600 3 Armco 900 Half silted with the Headwall & Wingwalls broken and water stagnants

i i l60+880 CP 1 900 CP 1 900 Half silted with Headwall and Wingwalls having cracks

60+980 CP 1 900 CP 1 900 Half silted

61+080 CP 1 900 CP 1 900 Half silted


61+230 Armco 1 2500 Armco 1 2500 Retain & Clean Headwall & Wingwalls exist only the downstream stream side.

64+280 CP 1 900 CP 1 900 Retain & Clean Fully silted with both Headwall & Wingwalls broken

64+380 Armco 2 900 Armco 2 900 Retain & Clean Half silted with stagnant water in the middle

64+400 Armco 2 600, Armco 1 900 Armco 2 600,Armco 1 900

Retain & Clean Half silted with stagnant water in the middle


64+830 Armco 1 2500 Armco 1 2500 Retain & Clean Headwall & Wingwalls are cracked at the upstream end

65+480 Armco 1 600 2 Armco 900 Headwall and Wingwalls are broken.

66+780 Armco 1 1200 Armco 1 1200 Retain & Clean Headwall & Wingwalls are cracked.

66+930 Armco 1 600 2 Armco 900 Headwall & Wingwalls are cracked.

67+030 Armco 1 900 Armco 1 900 Headwall & Wingwalls are carcked.


67+280 Armco 1 900 Armco 1 900 Half silted

68+030 Armco 1 900 Armco 1 900 Retain & Clean Half silted

68+230 Armco 1 900 Armco 1 900 Retain & Clean Completely blocked

68+230 Armco 1 900 Armco 1 900 Retain & Clean Half silted

68+580 Armco 1 600 2 Armco 900 The Headwall & Wingwalls have cracks.


68+780 CP 1 900 CP 1 900 Retain & Clean The Headwall & Wingwalls have cracks.

69+180 Armco 1 600 CP 1 900 3No. CP pipes blocked and crushed

69+430 Armco 2 600 CP 2 900 Completely blocked with broken head and Wingwalls



69+910 Armco 1 600 Armco 900 0,7 1 Half silted with the head & Wingwalls cracked

70+180 Armco 1 600 CP 1 900 Completely blocked and head & Wingwalls unplastered

71+080 Armco 1 600 CP 1 900 Culvert half way silted

71+650 CP 1 900 CP 1 900 Retain & Clean Culvert half way sited with 1No. CP damaged

25 Year

Peak

Flow

Observations

Remedial Action

ExistingChainage

Existing

Capacity

of

Culverts

m3/s

2,4 1

5,3 7

7,5 1

1,8 3

26,1 41

6,6 6

12,3 8

6,3 2

5,9 23

3,3 7

12.2 325

3,9 8


13/25




- 5 -


71+850 CP 1 600 Armco 900 0,7 1 Culvert half way silted

72+250 CP 1 900 CP 1 900 Retain & Clean Culvert half way silted with no Wingwalls

72+850 Armco 2 900 Armco 2 900 Retain & Clean Culvert half way silted

72+950 Armco 2 900 Armco 2 900 Retain & Clean 2No. CP pipes on downstream to be replaced & Headwall damaged

73+000 Armco 1 600 Armco 1 600 Retain & Clean Gully formed at downstream end

74+100 CP 1 900 CP 1 900 Retain & Clean Headwall and Wingwalls not plastered

74+800 Armco 1 900 Armco 1 900 Retain & Clean Headwall unplastered with cracks without Wingwalls

74+950 Armco 1 1200 Armco 1 1200 Retain & Clean Headwall unplastered with cracks.

75+000 Armco 3 900 Armco 3 900 Retain & Clean Headwall unplastered with cracks without Wingwalls

75+050 Armco 1 900 CP 2 900 Headwall unplastered with cracks without Wingwalls

75+750 CP 1 900 CP 2 900 Headwall unplastered with cracks without Wingwalls

75+850 Armco 1 900 CP 2 900 Headwall unplastered with cracks without Wingwalls, culvert filled with

76+000 Armco 1 900 CP 2 900 Headwall exists at only at down stream side

76+020 Armco 1 900 Armco 1 900 Retain & Clean Half silted with unplastered Wingwalls having cracks

77+150 Armco 1 600 2 Armco 900 Headwall unplastered with cracks without Wingwalls and half silted

77+750 Armco 1 600 2 Armco 900 Headwall have cracks

77+800 Armco 1 900 Armco 1 900 Retain & Clean 1,1 0,4 Headwall unplastered with cracks without Wingwalls

78+150 Armco 1 900 Armco 1 900 Retain, Repair and Clean 5No. Culverts vandalised

78+750 Armco 1 900 Armco 1 900 Retain, Repair and Clean Headwall & Wingwalls have cracks and half silted

78+750 Armco 1 600 Armco 1 600 Retain, Repair and Clean Headwall unplastered with cracks without Wingwalls and half silted

79+000 CP 1 600 CP 1 600 Retain, Repair and Clean Half silted with stagnant water in the middle and upstream Headwall

79+150 Armco 1 900 Armco 1 900 Retain, Repair and Clean Headwall & Wingwalls have cracks

79+250 Armco 1 600 Armco 900 Half silted with unplastered Headwall and Wingwalls don't exist.

79+350 Armco 1 1200 Armco 1 1200 Retain & Clean Downstream Headwall not plastered

80+200 Armco 1 450 Armco 900 Headwall are not plastered

80+650 Armco 1 600 Armco 1 600 Retain & Clean

80+950 Armco 1 900 Armco 1 900 Retain & Clean Headwall and Wingwalls are not plastered



81+330 Armco 1 600 Armco 1 600 Retain & Clean Half silted with Headwall & Wingwalls have cracks

81+350 Armco 1 600 2 Armco 900 0,7 4 Headwall & Wingwalls have cracks and are unplastered

81+500 CP 1 600 2 Armco 900 OK

81+900 Armco 1 2500 Armco 1 2500 Retain Completely silted without Wingwalls

83+500 Armco 1 2000 Armco 1 2000 Retain Headwall are not plastered

83+550 Armco 1 900 Armco 1 900 Retain & Clean Headwall & Wingwalls have cracks and are unplastered



84+100 Required Culvert CP 2 900 Culvert half way silted

84+700 Armco 1 900 Armco 1 900 Retain & Clean Completely blocked and sunk

85+400 Armco 1 900 CP 3 900 1,1 6 OK

85+600 Armco1 600 2 Armco 900 Slight cracking on the Headwall



87+100 Armco 1 900 2 Armco 900 OK


87+600 Armco 2 900 Armco 2 900 Retain & Clean 2,2 0,3 OK




90+650 Armco 1 900 Armco 1 900 Retain & Clean Headwall and Wingwalls not plastered with Wingwalls

91+750 Armco 1 900 Armco 1 900 Retain & Clean

91+850 Armco 2 900 Armco 2 900 Retain & Clean Headwall & Wingwalls have cracks and are unplastered

92+050 Required Culvert Armco 1 900

92+150 Required Culvert Armco 900 0,0 0,3 Culvert half way silted with Headwall & Wingwalls have cracks






99+950 Armco 2 900 Armco 2 900 Retain & Clean 2,2 0,3








107+750 Armco 1 600 Armco 1 600 Retain & Clean 0,7 0,3 Culvert half way silted















123+350 Required Culvert Armco 900 0,0 0,3



25 Year

Peak

Flow

Observations

Remedial Action

ExistingChainage

Existing

Capacity

of

Culverts

m3/s

3,7 3

4,4 5

1,1 4

9,7 24

5,6 7

3,3 1

2,0 3

3,7 1

2,4 6

4,6 1

2,9 3

9,0 18

5,5 6

Location with regard to the existent road


14/25




- 6 -

1.2. Bridges

The Hydrological Analysis was carried out for all the 11 Bridges to assess existing capacities against 50Year Flood Discharges. At the following table we have summarized the location of the bridges, the

bridges capacity assessment and the remedial actions.

5+570 5+570 Cipi 15 7.50 x 2.95 90.40 141 121 Maintenance Works

10+050 10+038 Cheptui 29 12.40 x 2.00 51.70 139 75 New Bridge11+200 11+193 J esebere 33 7.00 x 3.85 45.30 193 66 Maintenance Works

20+050 20+048 Tabagon 65 12.00 x 3.70 63.50 343 96 Maintenance Works

25+575 25+572 Atari 76 7.75 x 2.70 114.6 128 167Gabion Protection Work and

Realignment of the Upstream

River Channel

32+880 33+033 Seretyo 86 7.70 x 2.10 245.90 84 360 New Bridge

42+180 42+168 Gilig 105 24.00 x 8.50 1365.7 2678 830 Structural StrengthImprovement

157+985 157+390 Lurenged 230 33.00 x 4.70 0.20 1,523 423 Maintenance Works

163+935 163+345 Namalera 235 11.90 x 3.50 40.00 305 28 Maintenance Works

168+985 168+389 Lokali 239 16.50 x 4.40 94.00 643 58 Maintenance Works

179+135 178+520 Nadunget 254 12.80 x 4.20 38.20 447 32 Maintenance Works

Remedial Acti onExisting Structure

Length Width (m)

Catchment

Area (Km2)

Existing

Capacity (m3/s)

50 Year

Peak Flood

(m3/s)

Current

Chainage

New

Chainage

Bridge

Name

Catchment

No

Cheptui Bridge (K.P. 10+038) is collapsed and it is necessary to replace it by a new bridge of the

same dimensions.

Atari bridge (K.P. 25+572) with a Discharge Capacity of 128m3/s against a Q50 Peak Discharge of

167 m3/s is recommended to be maintained, subject only to remedial maintenance its structural

condition is good and its Discharge Capacity is a little under Q25 Peak Discharge; however as the

Bridge has withstood Past Floods without Significant Structural Damage, the additional 40m3/scapacity required to pass the entire Q50 Peak Discharge does not economically justify the Bridges

replacement.

Seretyo Bridge (K.P. 33+033) requires to be replaced in order to accommodate the Q50 Peak

Discharge. Preliminary calculations indicate that a 20m bridge span with a height of 2.5m would be

required to pass the Q50 Peak Discharge of 360m3/s.

For the remaining 8 bridges, general rehabilitation works are only required.

At the following tables is summarized the bridge inspection report:


15/25




- 7 -


16/25




- 8 -


17/25




- 9 -


18/25




- 10 -


19/25




- 11 -


20/25




- 12 -


21/25




- 13 -


22/25




- 14 -


23/25




- 15 -


24/25




- 16 -


25/25




Documents

0403-DRAINAGE AND BRIDGE DESIGN .pdf