road design preliminary

i

Table of Contents

1. Introduction ....................................................................................................................... 1

1.1 Background ............................................................................................................... 1

1.2. Objectives ................................................................................................................. 1

1.3. Scope of Work .......................................................................................................... 1

1.4. Appointment of Consultant ....................................................................................... 2

1.5 Mobilization Consultant Team ................................................................................. 2

2 Appreciation of the Project and Field Visit ...................................................................... 3

2.1. Project Status ............................................................................................................ 3

2.2 Alignment ................................................................................................................. 4

2.3 Drainages System...................................................................................................... 5

2.4 Roadside Drains ........................................................................................................ 5

3. Economic Analysis: .......................................................................................................... 6

3.1 Estimating Cost: ........................................................................................................ 6

3.2 Salvage Value: .......................................................................................................... 7

3.3 Estimating Benefits: .................................................................................................. 7

3.4 Vehicle operating costs ............................................................................................. 7

3.5 Road maintenance benefits ....................................................................................... 8

3.6 Time-savings ............................................................................................................. 8

3.7 Reduction in Accident Cost: ..................................................................................... 8

3.8 Economic development benefits ............................................................................... 9

4. Engineering Survey ......................................................................................................... 10

5 Engineering Design of Roads ......................................................................................... 12

5.1 General .................................................................................................................... 12

5.2 Geometric Design of Highway ............................................................................... 13

5.2.1 Special Design Features .................................................................................. 14

6. Traffic Survey and Study ................................................................................................ 17

6.1 Objective/Purpose ................................................................................................... 17

6.2 Traffic Count Survey .............................................................................................. 17

6.3 Estimating Traffic Flows ........................................................................................ 18

7. Geology and Geo-technical Investigation:.................................................................. 20

7.1 Geology: .................................................................................................................. 20

7.2: Geotechnical Investigation: .................................................................................... 21

8 Design of Pavement ........................................................................................................ 22

8.1 General .................................................................................................................... 22

8.2 Traffic Count Results and Projected ESAL ............................................................ 22

8.3 Pavement Design .................................................................................................... 24

9. Hydrological Investigation.............................................................................................. 27

10. Cross Drainage Design ............................................................................................... 27

11. Construction Methodology ......................................................................................... 28

11.1 General .................................................................................................................... 28

11.2 Widening of Road Formation ................................................................................. 28

11.3 Construction of Granular Sub-base ......................................................................... 28

11.4 Construction of Granular Base Course: .................................................................. 29

11.5 Construction of Double Bituminous Surface Dressing/ Otta Seal .......................... 30

12. Cost Estimate: ............................................................................................................. 30

12.1 Engineers Estimates ................................................................................................ 30

12.1.1 General Introduction ....................................................................................... 30

12.1.2 Unit Rates........................................................................................................ 31

12.2 Quantities and Cost Estimates for Road Construction ............................................ 31

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List of Tables Table 1.A: Benefits and Costs as per Option 1.A Table 1.B: Benefits and Costs as per Option 1.B Table 2 Table of Benchmark Details Table 3: Design Parameters Table 4: Classified Manual Vehicle Count Table 5: Equivalent Standard Axle Load per unit Table 6: Computation of Equivalent Standard Axle Load and Projection Table 7: Pavement Thickness Design Table 8: Grading Envelop for Gravel Table 9: Physical Requirements of Graded Crushed Stone Table 10: Grading envelope for Graded Crushed stone base and sub-base Table 11: Adopted Abstract of Cost for 5.5m width DBST Carriage way and 0.75m width

Shoulder both sides exposed incorporating Nepal Urban Road Standard (Draft) with Nepal Road Standard by Department of Roads.

List of Figures Figure 1: Strategic Road Network in Mechi and Project Area Figure 2: Sahid Marga to be constructed Figure 3: A glimpse of Sahid Marga Figure 4: Bikram Salik at 0+210 Figure 5 SW-Roads Software Interface Figure 6: Format for Production of Quantity Calculation Figure 7: Format for Production of Summary and Extract of Quantities Figure 8: Geological Map of the Area Figure 9: Load dial reading Vs. Penetration graph of sample 1 Figure 10: Load dial reading Vs. Penetration graph of sample 2 List of Annexes Annex A: Social Safeguarding Annex B: Environmental Assessment

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1. INTRODUCTION 1.1 Background The second component under the Urban Governance Development Project (UGDP) – Emerging Towns Projects (ETP), under the funding of the World Bank, covers the socio-economic infrastructure development in the six candid Municipalities identified in the first phase of implementation. The six municipalities are Baglung, Tansen and Lekhnath in Western Region and Itahari, Dhankuta and Mechinagar in the Eastern Region. Upon the request from the Municipalities for their respective priority infrastructure projects, the Town Development Fund (TDF) has approved grant to each of these mentioned municipalities to finance the Feasibility Study and Detailed Engineering Design for seven sub–projects to be implemented at the initial stage as Fast Track sub–projects. The above municipalities were asked to prioritize projects having least environmental and social issues so that these sub-projects could be undertaken for immediate implementation as fast track sub-projects. The successful implementation of these fast track sub-projects by the municipalities will further attract more of such infrastructure projects within the municipalities in the coming years. For the purpose of carrying out the consulting services, the sub-projects are grouped into two Packages. The Package–1, for which this consultant is responsible for the services as per the Terms of Reference, consists of the following five sub-projects:

a) Beautification of Entrance Gate – Mechinagar Municipality b) Gokul Marg Blacktop Road, Northern Part – Mechinagar Municipality c) Sahid Marg Construction – Mechinagar Municipality d) City Area Surface Drainage Improvement, East – West Highway Segment – Itahari

Municipality e) Municipal Office Access Road – Baglung Municipality

1.2. Objectives The objectives of the consulting services subject to this Terms of References are to elaborate sub-project, based on the analysis of the physical, economic, financial, social, environmental, legal and institutional aspects prevailing in the area and alternative scenarios for the development of the proposed sub–project components. 1.3. Scope of Work The scope of work is divided into three phases for each of the sub-projects in the three municipalities. The consultant needs to carry out his obligations as per the Terms of References in three phases in succession one after the other. The consultant needs to move to the next phase only after review, decisions on modalities and approval of the first phase by the respective municipalities and clearance by The TDF. Though the consultant is working for the municipalities, TDF, the grantor of the assignment, will also monitor the consultant’s works. The three phases of the scope of works for each of the sub-projects are as follows:

1. Phase I: Project Concept and Feasibility Support In the Phase I of the Scope of Work the consultant should carry out the works which includes but not limited to the following specific steps:

A conceptual design and development of the proposed sub-project

Technical, financial and economic analysis

Examination of the critical risks and the problems (e.g. financial, social, legal and institutional risks)

Operational feasibility

2

2. Phase II: Project Engineering Design Support

After approval of the feasibility study and sub-project modalities by the municipalities and clearance by the TDF, the consultant will carry out the Phase II Scope of Work which includes but not limited to the following specific steps:

Recommendation, based on feasibility study and agreed modalities the consultant should carry out detailed engineering works , including the followings:

Complete detailed engineering design documents and detailed cost estimates;

Implementation Schedule;

Draft tender documents;

3. Phase III: Project Concept and Feasibility Support After approval of the subproject modalities and the engineering design by the municipalities and approval of project financing by TDF, the consultant will assist the municipalities with documents that facilitate the project implementation which includes;

Construction Schedule ;

Tender Documents; A broad description of the scope of works is described in the three phases above. However, there are few more project specific scopes of works according to the nature of the sub-projects. Terms of References, which is included with this report as an annex, describes the scope of works in detail for each of the following sub-projects;

a) Beautification of Entrance Gate – Mechinagar Municipality b) Gokul Marg Blacktop Road, Northern Part – Mechinagar Municipality c) Sahid Marg Construction – Mechinagar Municipality d) City Area Surface Drainage Improvement, East – West Highway Segment – Itahari

Municipality e) Municipal Office Access Road – Baglung Municipality

1.4. Appointment of Consultant To carry out the consulting Services for Feasibility Study and Detailed Engineering Design of Fast Track Sub-projects under Urban Governance and Development Program, Emerging Towns Project was awarded to MEH/CIAS JV. The Contract agreement for the services was signed on January 18 between the employer and the consultants. The consultant has commenced its service from 25th of January,2012. The assignment of the consulting services will complete within four and half months from the start date. The office of the consultant is set up in the premise of the MEH Consultant’s head office located in New Baneshwar. 1.5 Mobilization Consultant Team The Consultants Team includes: Professional Staff Designation 1. Mr. P. J. Shah Road Design Engineer /Team Leader 2. Mr. A. M. L. Das Sanitary/ Drainage Engineer/Dy. Team Leader 3. Mr. S. K. Karna Geotechnical Engineer/Specialist 4. Ms. S. Shrestha Architecture/Planner/Specialist 5. Mr. G. M. Tamrakar Civil Engineer/Specialist 6. Mr. G. K. Karna Survey Coordinator/Specialist 7. Ms. N. Shrestha Draftsman/CAD Operator/Specialist 8. Mr. S. S. Karki Environmental Specialist/Specialist 9. Mr. K. R. Mishra Social Safeguard Specialist/Specialist

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10. Mr. Y. R. Tamrakar Economist-Financial Expert/Specialist 11. Mr. R. R. Adhikari Civil Overseer/Specialist 2 APPRECIATION OF THE PROJECT AND FIELD VISIT The consultant teams members visited the site in February and have familiarized with the site condition, existing road design, standards adopted were verified with the alternative option as identified during desk study. The Team made a walk over survey along the full lengths of these sub-projects in all the municipalities to assess presently existing physical, environmental and social conditions. However, for two road sub-projects Gokul Marg and Sahid Marg in Mechinagar Municipality, the team has to drive along the road to assess the present status. The team identified and took note of the natural watercourses requiring cross-drainage structures. Similarly, settlement in the urban areas that may be affected by the widening of the road and the possible mitigation measures for improvement has been noted. It was observed that for whole of the proposed road length, only one major watercourse, over which a culvert exists, is there. Therefore no meticulous study or planning is deemed necessary for cross drainages. As the existing road is built entirely in the shallow embankment and there is no notable evidence of inundation, it is assumed that there will be no need of road side drains except in the built up areas near the start of the project and Prativa Chowk. Socio-environmental condition and issues on physical, biological, socio-economic, cultural aspects has been identified and are included in the Social Report. Similarly, property to be acquired, if any, has been in general assessed. From our preliminary design and study at field there is no need to acquire the additional land, since the Municipality have already allocated11m on either sides of the road centre line, within which the road will be content. However, there are few temporary houses/shops and few boundary walls of residential buildings built within the road corridor. The consultant, after thorough study of possible alternative alignments, has concluded that the present road corridor is the optimum alignment from technical and economic point of views. Thus, the consultant has followed the present road central line to carry out the detail design of the road without crossing the limits of the road corridor. 2.1. Project Status It is the other significant road within the municipality serving other emerging settlements. This road also serves the settlements in the north side of the highway. It is noted that more settlements are coming up towards north of the highway than towards south. The road passes through the business centre of Dhulabari market and ends at the Barne Chowk in the Mechi Rajmarg. This road once constructed may serve as Charali By-pass road for the vehicles to and from Mechinagar to Ilam and north.

Though the entire length of the Sahidmarg is about 10 kilometers, the present sub-project includes approximately 4.5 kilometers of the remaining portions of the road. The present black toped road ends just at the end of the forest area along the alignment. The sub-project starts from this point onwards. The alignment of the sub-project passes through a small length of the forest. However, the road corridor is clear of trees. The remaining portion of the road passes through the agricultural area and tea garden towards its end and it has graveled surface in the remaining portion of the road to be improved. The road alignment runs north south up to the approach road to the bridge over the Ninda Khola. Then it runs east to west up to the end of the project. The alignment running north south has no major natural drainage system. However, there are four numbers of irrigation canals crossing the road. The portion which runs east west has three existing culverts. Otherwise there is no major natural drainage system in the entire length of the road. The road shall be constructed in embankment except at short lengths at tea garden area and shallow gully cuttings. The road

4

alignment also passes through the refugee camp which is now vacated and destroyed. The road surface is graveled at many places along the road. As in the case of the Gokul Marg no tree has to be felled on the entire length of the alignment. The right of way of this road is also 11 meters on either side of the road from the centre line, as informed by the municipality. Few temporary shopping and tea stall may require removal or relocation from within the road corridor at the junction with the Mechi Rajmarg. Therefore, no major environmental or social issue seems to be of major proportion and obstacle to the sub-project. Environmentally, the road project should pose no effect in the area. The road passes through the agricultural area and it does not need felling of any trees for the purpose. It is observed that urbanization is fast growing alongside of the road. It can be expected that in the future it will grow more after the road is constructed. Along with urbanization few small and medium industries are likely to come up as the border with India is very close and vast area of the agricultural land is used for growing tea.. 2.2 Alignment The road corridor lies in the flood plains of the Ninda River in the east and other small rivulets in the west. It starts from the foothill of the Siwalik range in the north and ends at the Gangetic plains in the south. The general geology of the project area is alluvial deposits comprising silts, sand and clay as found in all over Terai region of the country. Most part of the land on either side of the road corridor is under cultivation and in the remaining part semi-urban and rural settlements and shops markets are either developed or are fast developing as ribbon development. More detail about the general land use is included in the social portion of the report. The existing alignment of the road is the most suitable alignment for the development of Dhulabari area as well as the surrounding rural area of the municipality. The municipality has demarcated the 22m wide corridor of the whole length of alignment. The existing road is a black toped road up to 5 kilometers and it has varying width of carriageway. The

East-West Highway

Mechi

Highway

Figure 12 Sahid Marga to be constructed

Project area

Figure 11: Strategic Road Network in Mechi and Project Area

5

formation width of the road also varies. The carriageway width varies from 6 meters wide at the start and up to 7 meters along most of the remaining road length. There are not many settlements along the road but it passes through the agricultural fields. The refugee camp is now deserted and there is no sign of settlement now. Towards the end of the project the alignment passes through the tea garden for about 500 meters. 2.3 Drainages System There are couple of properly constructed pipe culverts along the road. There is no proper road side drain constructed because the road is built in embankment except in Dhulabari and near the junction with East-West Highway in Dhulabari Chowk 2.4 Roadside Drains There is no proper storm drainage system functioning to drain off the water from the road surface. The runoff from the road surface automatically flows to the adjoining cultivated land. It is envisaged that few hundred meters of covered road side drains will be necessary near the start of sub-project i.e. halfpantchowk at Barne. A provision of covered drain is made for a length of 1000 metres to accommodate the local demand near the sparsely built-up area or near the future planned ‘Krishi Mandi’.

Junction with Mechi Rajmarg – End of

Sahidmarg

Tea Garden – Near Junction with

Mechi Rajmarg

SahidMarg

Now Destroyed Refugee Camp

6

3. ECONOMIC ANALYSIS: 3.1 Estimating Cost: The cost of a road project consists of the total cash expenditure incurred over the project’s life. There are two main components of this:

investment cost – development (construction and upgrading), renewal, rehabilitation; and

Recurrent costs – operation and maintenance. Once a capital investment has been made, this has an inevitable, on-going and never-ending consequence in terms of recurrent expenditure needs. Thus, capital investments should be subject to appraisal to determine whether or not a particular investment is worthwhile. Recurrent expenditures should also be subject to appraisal to determine the optimum expenditure mix across a range of possible options. The unit rate estimation technique is based on the traditional bill of quantity approach to pricing construction work. This contains the quantities of work to be carried out, measured in accordance with an appropriate method of measurement. The quantities of earthwork, drainage, pavement works have be extracted by the software called SW-Roads. These quantities thus extracted are multiplied by the rates calculated from detail rate analysis using respective district rates. For road maintenance, Robinson (1988) estimated a comparative cost as below: Road Type Activity Cost Range (units)

Paved and unpaved Routine and recurrent 1 to 5

Paved and unpaved Periodic 4 to 5

Paved Strengthening Overlay 25 to 40

Paved Rehabilitation 60 to 100

Option 1.A

Abstract of Cost of DBSD Shahid Marga (5.5m Road Inclusive of 0.75m SBSD Shoulder both sides )

S.No. Items Description Unit Amount for 5.5m

Road including 1.5m SBST

Remarks

1 General NRs. 625,000.00

2 Site Clearance NRs. 606,662.94

3 Earthwork NRs. 6,272,095.91

4 Pavement Work NRs. 30,169,596.55

5 Bituminous Work NRs. 27,741,880.19

6 Water Management NRs. 1,442,136.40

7 Road Furniture and Traffic Safety Measures NRs. 119,429.46

8 Bio-engineering Works NRs. 4,503.98

9 Provisional Sums NRs. 250,000.00

A Grand Total Amount NRs. 67,231,305.43

B Add10% Contingencies (10% of A) NRs. 6,723,130.54

C Total amount with Contingencies (A+B) NRs. 73,954,435.97

D Add 13% Value added Tax (VAT) (13% of A) NRs. 8,740,069.71

E Total Amount inclusive of Contingencies and VAT (C+D)

NRs. 82,694,505.68

Hence, Estimated Cost per Km section of the Road NRs. 16,676,414.85

The total cost of 82.694 million has been used for the purpose of economic analysis for this option (Option no. 1.A)

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Option 1.B

Abstract of Cost of DBSD Shahid Marga (5.5m Road excluding 0.75m SBSD Shoulder both sides )

S.No. Items Description Unit Amount for 5.5m

Road excluding 1.5m SBST

Remarks














E Total Amount inclusive of Contingencies and VAT (C+D)

NRs. 82,300,202.41


The total cost of 82.3 million has been used for the purpose of economic analysis for this option (Option no. 1.A) 3.2 Salvage Value: Due to the nature of pavement it is always not possible that each alternative have its life used up precisely at the end of the analysis period. One or more alternative may have some remaining value of life at a time (IS: 13174 Part II 1994). The final item in such cost analysis is salvage value at the end of the performance period, which in this instance is 10 years. In any event, discounting back from as far out as 20 years results in a reduction to only 13 % of the capital cost. (ISSN: 0975-5462, Vol. 4 No.03 March 2012, Mrs. Vidya Nitin Patil et al. / International Journal of Engineering Science and Technology (IJEST)) 3.3 Estimating Benefits: For major roads, the following benefits are normally considered:

Vehicle operating costs (VOCs)

Road maintenance benefits

Time savings

Reduction in accident costs

Economic development benefits 3.4 Vehicle operating costs VOCs are normally reduced when a road is improved. Road users perceive the savings through lower expenditures in the following areas:

Fuel consumption

Lubricating oil consumption

Spare parts consumption

Vehicle maintenance labour

Tyre consumption

Vehicle depreciation

Crew costs in commercial vehicles.

8

For the purpose of our calculation, Vehicle operating Cost data has been used from different project (Rural Transport Services Study and Policy Development). Vehicle Operating Costs in 4 districts at rural roads has been calculated by the consultant’s team. The 4 district comprises of two terai and two hills. Vehicle Operating Cost at terai can actually resemble the true nature in our case as well. It has been found from the studies that the vehicle operating cost differs from 1.35 to 1.9 times the original cost when the road is upgraded from graveled road to blacktopped road. (Source: D. Žilionienė, Assoc. Prof. A. A. Juzėnas, Prof. A. Laurinavičius, Vilnius Gediminas Technical University Road Department). 3.5 Road maintenance benefits Maintenance savings can normally be expected with the following types of projects:

paving a gravel road where traffic levels have exceeded the level of economic surface maintenance; and

Rehabilitation or renewal of a paved road that has deteriorated badly, since the improved road is less costly to maintain than the existing one.

Due to the current trend of maintenance, road maintenance cost at present is not considerable amount, hence this is not considered in our study. 3.6 Time-savings Shorter road alignments and higher average speeds will lead to savings of time. The benefits of shorter journey times will accrue to passengers being carried and to the commercial vehicle fleet because higher vehicle utilization can be achieved. The time costs of commercial vehicles include standing costs, such as crew wages, vehicle depreciation and interest on capital. Travel time-savings for passengers in buses and private cars should be divided into time-savings during working hours and during non-working hours. In the absence of better data, working time can be valued at the average wage rate, plus an element to cover social overheads. The value of non-working time depends on the willingness to pay for time by those who are commuting or traveling for private purposes. Normally there are little or no data on this aspect. It can be argued that, when unemployment is high and wages are low, the value of time is insignificant. However, the occupants of cars are normally from the highest income group of society, and are likely to value time relatively highly. Non-working time is then valued at a proportion of working time, typically in the range of 0–50 per cent. Time saving can be utilized by both vehicle and goods/passengers. If the vehicle reaches its destination on time, it can be used in other important works, or it can also stay idle which both costs money. For the analysis of time saving minimum cost is taken for vehicles’ use than its actual value. 3.7 Reduction in Accident Cost: In addition to the humanitarian consequences of reducing road deaths and injuries, a strong case can be made for reducing accidents solely on economic grounds, as they consume massive financial resources that countries can ill afford to lose. A study carried out of national accident costs in different countries (Jacobs et al.2000) expressed these as a percentage of Gross National Income. Results ranged from 0.3 per cent in Vietnam, and 0.5 per cent in Nepal and Bangladesh, to almost 5 per cent in the United States, Malawi and Kwa Zulu Natal in South Africa. It should be noted that, in this analysis, the costs determined by the different countries have been used directly and not amended in any way. However, relatively little is known about the accuracy of the costing procedures used in each country; for example, whether or not under-reporting of accidents has been taken into account; how damage-only

9

accidents have been assessed; what sums (if any) have been added to reflect pain, grief and suffering; if the human capital approach has been used, etc. The study shows total accident cost to be around 1% of Gross National Income. The major income of this area has been identified as agriculture. Total influence area of this road has been identified as nearly 8500kathas. Out of which agricultural area can produce income of 40,00,000 per year. 3.8 Economic development benefits The economy in the vicinity of the road may benefit if a road is improved or new access is provided. It may be easier to make trips to farms or markets, or other commercial centres. There may be benefits to agricultural producers because of reduced transport costs, which enable higher prices to be obtained at the farm gate for goods that are produced. Table 1.A: Benefits and Costs as per Option 1.A

Year

Co

nstr

ucti

on

Co

st,

Mill.

Rs.

Main

ten

an

ce

Co

st

To

tal C

ost

Salv

ag

e V

alu

e

User'

s C

ost

Savin

g

To

tal B

en

efi

t

Net

ben

efi

t

NP

V

IRR

Calc

ula

tio

n

To

tal C

ost

To

tal B

en

efi

t

82.69

1 82.69 0.83 83.52 0.00 19.86 19.86 -63.66 -56.84 -48.04 74.57 17.73

2 0.00 0.83 0.83 0.00 20.85 20.85 20.02 15.96 11.40 0.66 16.62

3 0.00 0.83 0.83 0.00 21.89 21.89 21.06 14.99 9.05 0.59 15.58

4 0.00 0.83 0.83 0.00 22.98 22.98 22.15 14.08 7.19 0.53 14.61

5 0.00 4.96 4.96 0.00 24.13 24.13 19.17 10.88 4.69 2.82 13.69

6 0.00 0.83 0.83 0.00 25.33 25.33 24.51 12.42 4.53 0.42 12.83

7 0.00 0.83 0.83 0.00 26.60 26.60 25.77 11.66 3.59 0.37 12.03

8 0.00 0.83 0.83 0.00 27.93 27.93 27.10 10.94 2.85 0.33 11.28

9 0.00 0.83 0.83 0.00 29.32 29.32 28.49 10.27 2.26 0.30 10.57

10 0.00 0.83 0.05 10.75 30.78 41.53 41.48 13.36 2.49 0.02 13.37

57.71 0.00 80.60 138.32

NPV @ 12 % DF (in Rs

Million) 57.71

IRR 32.51%

BC Ratio @ 12% DF 1.72

10

Table 1.B: Benefits and Costs as per Option 1.B

Year

Co

nstr

ucti

on

Co

st,

Mill.

Rs.

Main

ten

an

ce

Co

st

To

tal C

ost

Salv

ag

e V

alu

e

User'

s C

ost

Savin

g

To

tal B

en

efi

t

Net

ben

efi

t

NP

V

IRR

Calc

ula

tio

n

To

tal C

ost

To

tal B

en

efi

t

82.30

1 82.30 0.82 83.12 0.00 19.86 19.86 -63.27 -56.49 -47.66 74.22 17.73

2 0.00 0.82 0.82 0.00 20.85 20.85 20.03 15.96 11.36 0.66 16.62

3 0.00 0.82 0.82 0.00 21.89 21.89 21.07 14.99 9.00 0.59 15.58

4 0.00 0.82 0.82 0.00 22.98 22.98 22.16 14.08 7.14 0.52 14.61

5 0.00 4.94 4.94 0.00 24.13 24.13 19.19 10.89 4.65 2.80 13.69

6 0.00 0.82 0.82 0.00 25.33 25.33 24.51 12.42 4.48 0.42 12.83

7 0.00 0.82 0.82 0.00 26.60 26.60 25.77 11.66 3.55 0.37 12.03

8 0.00 0.82 0.82 0.00 27.93 27.93 27.10 10.95 2.81 0.33 11.28

9 0.00 0.82 0.82 0.00 29.32 29.32 28.50 10.28 2.23 0.30 10.57

10 0.00 0.82 0.05 10.70 30.78 41.48 41.43 13.34 2.44 0.02 13.36

58.08 0.00 80.22 138.30

NPV @ 12 % DF (in Rs

Million) 58.08

IRR 32.75%

BC Ratio @ 12% DF 1.72

4. ENGINEERING SURVEY The consultant to accomplish the detailed engineering design, entailing the geometric design of main carriageway at places, drainage locations and structures etc. are carried out during detail field survey and study. In the course of field survey, following types of surveys were carried out:

Walkover survey

Reconnaissance Survey

Chainage Survey

Base Line Survey

Center Line Survey

Topographic Survey Out of the above surveys, walkover, reconnaissance surveys are already carried out and the findings are already given under Project Status above. Chainage Survey: Chainage Survey has been carried out prior to establishing the Baseline and BM for detail survey. During this survey, centre line pegging at intervals of 20m as mentioned in ToR has been carried out. This helped in tracing the important features of the road during detail survey. This survey has been applied for further road surveys works. Base Line Survey: The horizontal and vertical coordinates are arbitrarily fixed as the length of road is not long. These arbitrary co-ordinates can be tied to the national grid if needed. D-cards were prepared for all the Baseline stations established along the project road. Centre line Survey: After establishing the horizontal and vertical control points through Baseline the consultant has been carried out the centre line survey. The purpose of the centre line survey is basically to fix the existing centre line of the road and check whether the existing centre line could be followed for the improvement. It helps to identify whether the shifting of alignment is necessary from various points of views such as use of existing structures, avoiding the additional land acquisition etc. Topographical Survey: The topographical survey for road consists of a strip survey along the existing road alignment and corridor covering up to its right of way. The detailed survey includes

11

among other, the benchmark survey, traverse survey along the proposed centre line and detail topographic survey for the production of Digitized Terrain Model (DTM). Similarly, the survey work includes established base line stations, horizontal control points and permanent reference beacons plus re-establishment of the horizontal and vertical alignment and cross-section. It also includes existing houses, electric and telephone poles, trees, culverts and other structure along the road within the road corridor. All survey works has been carried out using total stations machines to obtain comprehensive topographic surveys for use as the basis design and improvement. The Topography Survey covers the following tasks.

a) Topography with details such as: trees, water bodies, high-flood level b) Existing road details such as: formation width, paved area, access roads, bus bays,

footpath, parking places, traffic signs, islands, signals and ROW limits c) Existing cross-drainage details such as: pier, abutment, railing, river training works d) Existing power line details such as: high-tension poles, low-tension poles, transformers,

manholes e) Existing telecommunication details such as: poles, man-holes, cabinets f) Existing buildings such as: religious shrines, governmental building, residential building g) Production of a map of 22m wide road corridor in 1:1000 scale and with 0.2 m contour

interval h) Acquisition of coordinate point from the Department of Surveys and referencing of all the

survey coordinates to that obtained from the Department of Survey i) Establishing bench-marks at a maximum distance of every 500m or less depending upon

the visibility of points along the road. Details of the topographical survey drawings and the digital terrain model developed using the topographical data are shown in drawing.

Table 2 Table of Benchmark Details

S.N. Northing Easting R.L. Remarks

1 2,955,500.000 608,425.310 180.000 BM1

2 2,955,513.214 608,425.310 180.178 BM2

3 2,955,606.623 608,343.820 182.606 BM3

4 2,955,729.918 608,234.338 184.818 BM4

5 2,955,853.324 608,100.179 187.888 BM5

6 2,956,000.798 607,952.708 191.351 BM6

7 2,956,124.829 607,832.273 194.225 BM7

8 2,956,194.445 607,748.369 196.500 BM8

9 2,956,314.304 607,640.919 200.838 BM9

10 2,956,400.113 607,576.466 203.271 BM10

11 2,956,491.837 607,535.071 205.197 BM11

12 2,956,600.710 607,460.152 207.490 BM12

13 2,956,739.654 607,346.204 211.779 BM13

14 2,956,867.810 607,243.730 215.752 BM14

15 2,956,994.716 607,185.308 218.916 BM15

16 2,957,242.854 607,105.606 224.605 BM16

17 2,957,425.491 607,034.274 229.845 BM17

18 2,957,586.645 607,006.411 233.507 BM18

19 2,957,746.404 607,009.914 237.464 BM19

20 2,957,869.499 606,965.471 241.078 BM20

21 2,958,010.767 606,975.766 243.786 BM21

22 2,958,127.722 606,894.655 247.281 BM22

23 2,958,252.652 606,839.588 250.336 BM23

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S.N. Northing Easting R.L. Remarks

24 2,958,378.519 606,795.300 254.782 BM24

25 2,958,597.440 606,686.369 261.807 BM25

26 2,958,633.617 606,540.009 263.734 BM26

27 2,958,551.134 606,437.341 270.976 BM27

28 2,958,581.766 606,370.315 271.747 BM28

29 2,958,578.897 606,263.580 277.711 BM29

30 2,958,604.091 606,112.078 280.661 BM30

31 2,958,628.530 605,995.079 283.512 BM31

32 2,958,650.356 605,922.842 283.663 BM32

33 2,958,665.611 605,802.048 287.156 BM33

34 2,958,706.765 605,628.190 288.151 BM34

35 2,958,711.344 605,574.845 288.639 BM35

Figure 13 A glimpse of Sahid Marga

5 ENGINEERING DESIGN OF ROADS 5.1 General The geometrical design is prepared to meet all the parameters given in the term of reference. The engineering design for road upgrading work mainly consists of the followings;

Design of Main Carriageway)

Design of Service Road

Design of intersections, if any.

Design of Service roads, if any. The structural design of different elements of the Highway involves the design of the following elements separately.

Geometric design

Pavement design

Road side drain design

Cross-drainage structure design Generally, the road design is carried out to include the following elements as given in the terms of reference.

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Design of the vertical and horizontal alignment for a design speed of 60 kmph

Design of highway carriageway cross-section

Design of cut and fill slopes

Structural design of retaining structures

Structural design of all RCC structures (excluding the bridges and the underpasses, if any)

Production of design drawings showing plan in 1:1000 scale, longitudinal profile in 1000H:100V scale cross sections at 10m interval in 1:100 scale

All the coordinates in the drawings are in referenced arbitrarily. 5.2 Geometric Design of Highway The geometric design effectively superimposes a new, designed surface over the existing ground surface. The existing ground surface, modeled as a digital terrain model (DTM), is prepared from a detailed topographical survey carried out using accurate survey instruments such as Total Station, EDM and Leveling Machines. Geometric design is then prepared digitally, using the standard parameters of double lane carriageway with, as discussed and agreed during the presentation and meeting held thereafter. However, the design capacity or volume of traffic requires intermittent lane road by the end of the design of road which is 10 years. The design parameters given in the terms of reference are included while preparing the geometric design. The computer-aided design process then maps the design surface over the existing ground surface and evaluates quantities, profiles, and surface intersections, (fills, cuts etc) and produces design drawings and quantity estimates.

Figure 14 Bikram Salik at 0+210

The design of road was prepared using AutoCAD and design software produced by Softwel Pvt. Ltd as follows:

SW_ DTM for Digital Terrain Modelling

SW_ Road for Highway Design These two soft wares SW_DTM and SW_Road are widely used in Nepal for the design of roads of all classes. SW_DTM is software developed by Softwel Pvt. Ltd. And it provides complete package solution for Digital Terrain Modeling. This software has interactive module for plotting of survey points, triangulation and plotting of contours at any contour points at any contour interval. The program

14

provides facilitation to extract data and draw plan, profile/cross-sections for any alignment and can be plotted in AutoCAD in any scale along with the data extraction as required by the users. As mentioned in ToR, contours are drawn in 0.2m intervals to prepare the DTM for design purposes. All the features like, roadside structures. Telephone poles, electric poles, transformers, tress, shrines, buildings etc are shown in the DTM. SW_Road is road designing software which has been used for the design of existing Belhiya-Butwal Road for upgrading to six lane standards. This software generates precise road design outputs considering all parameters of road design. It produces all plans, profiles and the cross-sections. The quantity calculation is done by the software and the output obtained in Excel format and drawings such as plans, profiles and cross-sections are produced in AutoCAD file format. 5.2.1 Special Design Features

Longitudinal Gradient/Radius of Curvature: The Nepal design standards were adhered to, for the design of the project road. The existing curvatures along the road, which were less than that required for 60kmph design speed, were increased as far as possible.

Design Speed: A design speed of 60 kmph was applied to finalize the design. All other design parameters, confirming to the requirement of the above mentioned design speed is taken into consideration in the geometric design.

Extra Widening: Extra Widening is basically provided in sharp bends with small radius curvature when the rear wheel of the vehicles tends to go outside the carriageway.

Super elevation: When determining the super elevation of any road, it is expressed as,

Where, =super elevation

= coefficient

= design speed in kmph

=radius of curvature

C=constant

From the above equation it is clear that super elevation depends on radius of curvature and design speed. In case of BB road, design speed is considered 80KMPH, minimum radius of curvature is 240m, and hence the Maximum super elevation provided in this road is 3% due the larger radius of curvature.

Design Parameters: Some of the important parameters considered for the design of road are shown in the table below. These parameters are the data required by the road design software S_W Road.

Table 3 Design Parameters

Sn Descriptions Inputs Unit Notes

1 Carriage Way

1.1 Road Width 7 m

1.2 Camber Slope 3 %

2 Vertical Alignment

Design

2.1 Design Speed 60 Km/hr

2.2 Stopping Sight Distance 80 m

15

Sn Descriptions Inputs Unit Notes

2.3 Minimum Vertical Curve

Length 20 m

2.4 Minimum Change in

Grade 1.5 %

3 Super Elevation Design

3.1 Maximum Outer Edge

Slope (1in..) 60 m

3.2 Normal Outer Edge

Slope (1in..) 100 m

3.3 Minimum Super

Elevation 3 %

4 Extra Widening Design

4.1 Extra Widening Transition Rate

0.1

m/m

For Extra Widening

Totally Outside the Curve

4.2 Fixed Transition Length 10

m Fixed Length Irrespective of

Widening

4.3 Extra Widening

Placement Method 1

0 for Totally Inside

1 for 1/3 Inside

2 for Totally Outside

4.4 Extra Widening

Transition Length Calculation 0

0 for Transition

Rate 1 for Fixed

Length

5 Design Override for Hill

Roads

5.1 Minimum Length of

Curve for Sup & ExWid 10 m

6 Right of Way

6.1 Right of Way 11 m Either Direction

7 Starting Chainage

7.1 Starting Chainage 0 m

Plotting of Drawings: The Highway design software SW_Road, as mentioned above, generates the drawings, which can be plotted in AutoCAD format as shown in the figure below. Few sample drawing generated by the soft ware are presented as follows.

16

Figure 15 SW-Roads Software Interface

Quantity Calculation: The Design software has the facility to calculate the quantity of various items in the Excel format as shown below. Besides that, it provides the cumulative quantity in a summary format as shown below as sample.

Figure 16: Format for Production of Quantity Calculation

17

Figure 17: Format for Production of Summary and Extract of Quantities

6. TRAFFIC SURVEY AND STUDY Transport Planning requires understanding of all types movements of all types of modes of transport. This includes vehicles, pedestrian carts etc. The understanding of transport planning involves determination of vehicle or pedestrian numbers, types of vehicles. To determine the numbers of vehicles and the pedestrian, traffic count data is needed. Present traffic at Sahid Marga is significantly low. Present data if used in projection of traffic for design period risks the fact of misinterpretation. This road is to serve as a bypass road to Charali decreasing substantial distance, vehicle operating cost and travel time. Hence, the present traffic data is to be taken at Charali Chowk depicting all directional flows. 6.1 Objective/Purpose

The purpose of the traffic survey/study is to ascertain the number of different types of vehicles using the road or highway. The data thus obtained by survey are analyzed for the following objectives;

Projection of traffic growth for the design period,

Capacity of the road or the lanes,

Calculation of the equivalent standard axle load (ESAL) for pavement design and

6.2 Traffic Count Survey The Terms of Reference does not mention about the traffic survey. However, for the purpose of pavement design and economic analysis of Sahid Marg subproject, the traffic count data of Charali Chowk has been used which is provided to the consultants’ team by the Road Boards Nepal. For pavement design purposes it is necessary to consider not only the total number of vehicles that will use the road but also the wheel loads (or, for convenience, the axle loads) of these vehicles. The loads imposed by private cars do not contribute significantly to the structural damage. For the purposes of structural design, cars and similar sized vehicles can be ignored and only the total number and the axle loading of the heavy vehicles that will use the road during

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its design life need to be considered in this context, heavy vehicles are defined as those having an axle load of 3000 kg or more. The equivalence factor for 3000 kg axle load is only 0.01 which means a vehicle having axle load of 3000 kg can do damage worth of 1% of design heavy vehicle. 6.3 Estimating Traffic Flows Traffic flow rate at Charali North, Charali East and Charali West has been extracted from the data provided by the Road Board Nepal. This data is based on the latest study conducted on year 2011 on different 160 locations of Strategic Road Network specified by the Department of Roads. The traffic counting with the classification of vehicle types with manual or video recording method for continuous 72 hours was done at those stations. Traffic count at Sahid Marga itself was very less, inappropriate for pavement design. Hence, some part of traffic at Charali north and east which may use Sahid Marga after the construction is done is used in the traffic analysis and pavement design. The percentage of traffic that are estimated to use new short route bypassing Charali Chowk are given below: All kinds of trucks and buses: 5% Remaining others excluding three wheelers, rickshaw, bullock cart: 20% Traffic Growth Factor: Average annual growth rate of 7.5% has been taken as a growth factor for the calculation of design Equivalent Standard Axle Load for the design period. This value is recommended by Indian Road Congress when adequate data are not available.

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Table 4: Classified Manual Vehicle Count

STN

No.

Station Name

Volume of vehicles

AADT in PCU

s

Truck Bus

Car Motorcycle

Utility

Vehicle

Tractor

Three Whee

ler

Rickshaw

Bullock

Cart

4W Drive/ Geep/Van

Power

Tiller

Multi Axle

Heavy

Light Bi-Axle

Mini Micro

2 Charali

East 162 271 163 189 630 256 754 3476 265 181 5 176 10 278 6 7150

3 Charali West 184 456 269 306 710 304 748 3446 505 222 18 66 0 511 21 9588

4 Charali North 19 154 185 121 121 107 438 2110 341 127 5 370 0 413 8 5240

xx Charali

north east 9 21 17 16 38 18 238 1117 121 62 2 109 2 138 3 2478

Traffic Volume considered for pavement design

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7. GEOLOGY AND GEO-TECHNICAL INVESTIGATION: 7.1 Geology: The Himalaya was formed due to collision of Indian Plate and Eurasian Plate at about 40 million years ago. It extends in 2400km east - west direction. Its width varies from 230 to 320 km and bounded between the Indo-Gangetic Plain in the south and Tibetan Plateau in the north. Nepal Himalaya occupies the central 800km part. It can be divided into five distinct morpho-geotectonic zones, from south to the north as (1) Terai Plain (2) Sub Himalaya (Siwalik Range), (3) Lesser Himalaya (Mahabharat Range and mid valleys) (4) Higher Himalaya and (5) Inner Himalaya (Tibetan Tethys). Each of these zones is clearly identified by their morphological, geological and tectonic features. Main Frontal Thrust (MFT), Main Boundary Thrust (MBT), Main Central Thrust (MCT) and South Tibetan Detachment Fault system (STDFS), from south to the north respectively are the major linear geological structures that act as the boundary line between the two consecutive units. From mineral resources point of view, Terai Plain is potential for gravel, sand, ground water and petroleum. The Sub Himalaya is the potential area for construction materials, petroleum and natural gas. Similarly, Lesser Himalaya is promising for metallic minerals, industrial minerals, marble, gemstones, fuel minerals, construction materials etc. Some of the areas in Higher Himalaya are highly promising for precious and semiprecious stones, marble and metallic minerals. Tibetan Tethys zone is prospective for limestone, gypsum, brine water (salt) and natural gas.

Mechinagar Municipality

Figure 18 Geological Map of the Area

The geological structure of the region consists of old and new alluvium, both of which constitute as alluvial deposits mainly of sand, clay, silt, gravels and coarse fragments. The new alluvium is renewed every year by fresh deposit brought down by active streams, which engage themselves in fluvial action. Old alluvium is found rather away from river courses, especially on uplands of the plain where silting is a rare phenomenon. The Terai region has a large number of small and usually seasonal rivers, most of which originate in the Siwalik Hills. The soil in the Terai is alluvial and fine to medium textured. Mechinagar Municipality is composed geologically by quaternary Alluvial river deposits whereas in the north there is middle-Miocene to Pho-Pleistocene molassic fluvial deposits known as Siwalik Group. It mainly consists of conglomerates, sandstones and shale with vertebrate fossils according to the geological map of Nepal.

http://en.wikipedia.org/wiki/Alluvium

http://en.wikipedia.org/wiki/Flood

http://en.wikipedia.org/wiki/Silting

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7.2: Geotechnical Investigation: The consultant completed geotechnical investigation of the existing road pavement and determined sub-soil condition through pitting and lab CBR test at Sahid Marga. The main purpose of the geotechnical investigation was to assess the strength of the existing pavement and other parameters required to design the road pavement. The two soil samples collected from Sahid Marga was brought to CIS lab for testing of California Bearing Ratio value. To replicate the existing soil condition, compaction from 90-95 % was achieved and testing was done. From lab results, CBR value was obtained to be 28.2% and 28.5% for sample 1 and sample 2 respectively. An average value of 28.35% is incorporated in the design of pavement. The details of the CBR tests are incorporated in the annex of this report.

Figure 19: Load dial reading Vs. Penetration graph of sample 1

Figure 20: Load dial reading Vs. Penetration graph of sample 2

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8 DESIGN OF PAVEMENT 8.1 General Pavement design consists of design of sub-grade, sub-base, base and bituminous layers for each section where the sub-surface conditions and traffic volume changes. Pavement design in Sahid Marg is carried out based on the TRL Overseas Road Note 31. Basic parameters considered are sub-grade CBR and Traffic Class. Maximum use of existing pavement is made as the sub-grade for the pavement. The major improvements recommended as follows:

As far as possible embankment is raised so that sub-grade level is above the natural ground level by minimum of 0.5m.

Construct double lane of width 7 with no shoulders.

8.2 Traffic Count Results and Projected ESAL An Axle Load of 10.2 T is adopted for pavement design. This value when combined with the projected traffic volume over the design period, determines the total predicted traffic loading the road will carry over its design life. This is expressed in terms of millions of equivalent standard axles. Axle Load is considered 10.2 t for trucks. Unit Equivalent Factor of axle load for trucks are based upon the 10.2t of axle load whereas, the unit equivalent axle load for other types of vehicles are taken from the recent survey carried in other roads of similar terrain and geographical conditions. The unit equivalent factors are listed in Table 2. The axle equivalent factor is computed using the equation (axle load/8160)4.5 recommended by TRL ORN 31. For the purpose of the pavement design only commercial vehicles (bus, truck, minibus, mini truck and tractor) are considered whereas traffic with un laden weights of less than 1.5 tones are not considered as the damaging factors are negligible for light vehicles. Table 5: Equivalent Standard Axle Load per unit

Type of Vehicles

Truck Mini Truck

Bus Mini Bus Tractor

ESAL 2.73 0.97 0.90 0.15 0.20

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Table 6: Computation of Equivalent Standard Axle Load

Charali north east 2478

Equivalence factor

ESAL

0 0.06

120.91

0 0 1.24 0 0 0

0 0 0.02

24.57 57.33 16.49 15.52 5.7 0 0

0 0 0 0.02 0 02.73 2.73 0.97 0.97 0.15 0

62 2 109 2 138 39 21 17 16 38 18 238 1117 121

STN

No.Station Name

Volume of vehicles

Micro

Three

Wheeler

Ricks

haw

AADT

in

PCUs

Truck BusCar

Motor

cycle

Utility

Vehicle

Tract

or

Bullock

Cart

4W Drive/

Geep/Van

Power

TillerMulti Axle Heavy Light Bi-Axle Mini

Design Parameters:

Design Life (n): 10 yrs

Annual Growth Rate (r): 7.5% 7.5%

Vehicle Damage Factor (F): IRC guides us to use this value of 1.5 for Rolling/Plain terrain when there is less than 150 commercial vehicles per day.

1.5

Lane Distribution Factor (D): for double lane, 75% of traffic from both direction are used in design.

0.75

Initial traffic in the year of completion of construction (A)

Present Traffic in terms of commercial vehicles per day (P) 121 ESAL

Total period of construction (x) 1 yr

Hence, A=120(1+.075)^1 130

A=130 commercial vehicle per day.

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A=130 commercial vehicle per day.

Design Traffic in terms of Equivalent Standard Axle Load (N):

Hence, Design Traffic = = 1,133,437

= 1.13 million ESAL. 8.3 Pavement Design

Pavement thicknesses are calculated depending upon the design parameters such as site conditions, existing pavement, and sub-grade soaked CBR, sub-grade CBR from DCP test results and Equivalent Standard Axle Load (ESAL) value. The sub-grade strength is assumed as that of the similar project such as Urlabari-Bardanga Road constructed under Asian Development bank finance.

The pavement thickness design has been carried out primarily using the design parameters in Chart 1 of TRL Road Note 31 page 52 and 53.

The resultant design thicknesses are presented in Table 4 below. Table 7: Pavement Thickness Design

Road Section Adopted Design CBR for

Pavement Design (%)

ESAL in 106

Design Parameters Design thickness in mm as per

TRL ORN 31

From km To km Sub-grade Class

Traffic Class

Surface) Base (mm)

Sub-base (mm)

0+000 2+500 28.35% 1.13 S5 T3 DBSD 175 100

*127*1.5*.75

25

26

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9. HYDROLOGICAL INVESTIGATION Though the entire length of the Sahid Marg is about 9 kilometers, the present sub-project includes approximately 4.5 kilometers of the remaining portions of the road. The present black toped road ends just at the end of the forest area along the alignment. The sub-project starts from this point onwards. The alignment of the sub-project passes through a small length of the forest. There is no evidence of flooding and problem of inundation in the project area. Therefore, it is assumed that no hydrological investigation is required. There is no evidence of over flowing or breaching of the banks by the flood waters at the location of existing culverts, and no evidence of flooding and problem of inundation and water logging for long periods along the entire project area. Therefore, it is assumed that no hydrological investigation is required. This is true in the sense that except the along the road running east to west other places of natural water course are so small that the catchment area is negligible and hence the discharge. Therefore, it has been concluded that there is no need of detailed hydrological investigation for this road sub-project. 10. CROSS DRAINAGE DESIGN Control over seepage, groundwater and surface runoff is one of the most important aspects in the construction of highways and roads. Physical properties of water make it highly destructive material. It is nearly incompressible and it has no shear strength, therefore, it can penetrate into most minute cracks and pores under pressure. This property of penetrating into minutest of cracks and pores under pressure can exert tremendous force resulting into collapse of structures, mountain slopes and erosion of the earth surface etc. The purpose of design of drainage systems for the roads or highways is to manage the safe passage of all types of water away from the road reserve. In spite of the destructive potential of water forces, there are two fundamental methods used alone or in combination to protect the road. These are:

I. Seepage reducing method by lowering the quantities of seepage or diverting it from places where in can cause harm.

II. Drainage methods which safely allows the water through without allowing it to cause damage.

Generally, for roads, water is managed through two types of structures;

1. Cross-Drainage structures 2. Side Drains along the entire length of road

Road side drains are constructed through out the length of the road where as, the cross drainage structures are constructed, general at the places of existing natural gullies and at places where the road has valley curves along its profile. Wet areas having high under ground water table may be encountered at places along the road. These areas as well as other spots of seepages may require special treatments for safe passage of water away from the road. The road alignment runs north south up to the approach road to the bridge over the Ninda Khola. Then it runs east west up to the end of the project. The alignment running north south has no major natural drainage system except one culvert in the jungle area. The portion, which runs along east west, has few existing culverts. Otherwise there is no major natural drainage system in the entire length of the road. The road shall be constructed in embankment except at short lengths at tea garden area and shallow gully cuttings. The road alignment also passes through the refugee camp, which is now vacated and destroyed.

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As the road is built in embankment and it runs the north south direction, it acts as a ridge for the surrounding areas dividing the existing catchment area into two parts. Therefore, it is assumed that three numbers of culverts have to be built to facilitate the irrigation canals to cross the road from east to west or vice versa. For the road portion which runs east to west there are three numbers of culverts. There is no sign of flooding and inundation in the area. Therefore, it is assumed that these culverts are working properly. However, maintenance or renovation of the existing culverts will be required and these are included in the bill of quantities. Pipe culverts of size 600 mm diameters are recommended for crossing the irrigation channels. Smaller size pipe culvert could be sufficient for the purpose but from maintenance point of view 600 mm diameter pipes are preferred. The standard drawing for 600 mm diameters pipe culverts of the Department of Roads is adopted as the design of the culvert. It is envisaged that few hundred meters of covered road side drains will be necessary near the start of sub-project i.e. at Barne Chowk. A provision of covered drain is made for a length of 1000 metres to accommodate the local demand near the sparsely built-up area or near the future planned ‘Krishi Mandi’. 11. CONSTRUCTION METHODOLOGY 11.1 General Construction methodology for different items of works is described below:

Widening of Road Formation where ever needed.

Construction of Granular Sub base

Construction of Granular Base Course

Construction of Double Surface Bituminous Treatment.

11.2 Widening of Road Formation The formation level of the road is almost prepared except some improvement is needed to follow the new design grade level. Since the road is to be constructed over already opened road, centerline of the existing road has been followed wherever possible. The existing road in general is constructed on Embankment fill. But in some places road is overtopped by the monsoon run off. These particular locations are raised during geometric n such a way so that the top of formation would be at least 500 mm above the normal flood level. The existing ground needs to be cleaned of vegetation and other deleterious materials and removed any unsuitable materials before preparation of foundation for embankment fill. After removal of vegetation, top soil and deleterious materials, the foundation shall be leveled and compacted to receive the embankment fill materials. The embankment will be prepared in the entire width. Compaction shall be done properly with appropriate rollers to achieve the density of each layer as per the requirement of specifications. If any weak spots are encountered during the preparation of the sub-grade such spots would be specially treated. Any unsuitable/detrimental material will be removed. The area will be compacted as far as practicable and possible. Then a reasonable thickness of suitable material will be laid and compacted to the required density. Following the treatment of weak spots as mentioned above consecutive layers of fill material will be applied and prepared the sub-grade. 11.3 Construction of Granular Sub-base The existing road is graveled. During design, efforts have been made to incorporate the existing pavement materials as far as possible. In some critical locations where monsoon ran overtops the existing road it has been raised. Sub-base materials shall be obtained from approved

29

sources in borrow or cut or from such other sources of supply as may be specified or approved from time to time for use. Gravel: The grading of the material after placing and compaction shall be a smooth curve within and approximately parallel to the envelope given in Table below: Table 8: Grading Envelop for Gravel

Sieve Size (mm) Percentage Passing by weight

63 100

40 70-100

20 50-85

10 40-75

4.75 30-60

2.36 20-45

1.18 15-35

0.075 4-15

Sands, Silty and Clayey Sands:

% passing 2 mm sieve : max 95%

% passing 0.075 mm sieve : min 10 – max 30%

Plasticity Index : min 5 – max 12%

Plasticity Modules : max 300% (PI_ % passing 0.425 mm sieve) All Materials The new granular sub-base material to be used shall conform to sub-base specifications and have a soaked CBR of not less than 30% after 4 days of soaking when compacted to 95% of MDD with heavy compaction, a swell less than 1% and plasticity Index and organic content less than 6% and 3% respectively. These materials are dumped on the finished sub-grade, spread, watered, mixed, laid and compacted to the density mentioned above to complete the surface for receiving the granular baser course. 11.4 Construction of Granular Base Course: Granular base shall consist of crushed stone, free from clay, organic or other deleterious matter. It shall comply with the physical requirements defined in Table below: Table 9: Physical Requirements of Graded Crushed Stone

Where, B, C1 are different classes of materials.

30

The gradation of crushed stone for base material should comply according to the table below, Table 10: Grading envelope for Graded Crushed stone base and sub-base

The minimum dry densities to be achieved as a percentage of the MaximumDry Density (MDD) determined in accordance with IS 2720 Part 8 shall be 98% of MDD for Base material. 11.5 Construction of Double Bituminous Surface Dressing/ Otta Seal DBSD: When Base course is completed the surface shall be cleaned and applied the prime coat. After completion of binder Curse, Single graded aggregate of designed specification shall be applied followed by the other layer of single graded aggregate according to the specification and thickness suggested by TRL ORN 32. Ottaseal: When base course is completed the surface shall be cleaned and graded aggregate shall be placed on a relatively thick film of comparatively soft binder which, on rolling and trafficking, can work its way upwards through the aggregate interstices. In this manner, the graded aggregate relies both on mechanical interlocking and bitumen binding for its strength –“a bit like” a bituminous premix. If this method of surfacing is selected , ‘A guide to the use of Otta Seals’, publication number 93 by Norwegian Public Roads Administration is recommended to follow. 12. COST ESTIMATE: 12.1 Engineers Estimates 12.1.1 General Introduction The Consultants’ JV have prepared an Engineer’s Cost Estimates and Bill of Quantities for the Project Road. First of all one comprehensive Cost Estimate and Bill of Quantities is prepared. The Engineer’s Estimates for the road construction and pavements works were prepared based on an evaluation of the unit rates and quantities obtained from the preliminary designs and inventory, costing has been carried out in the format using District Rates and Norms for Rate analysis approved by the Government of Nepal, Ministry of Physical Planning and Works, Department of Roads. The wages of local skilled and unskilled labor are based on approved district wages rates. The cost of equipment includes, owning, running and maintenance and equipment and cost for operators.

31

12.1.2 Unit Rates Having established a breakdown of the items for inclusion in the Bill of Quantities an analysis was undertaken to establish the unit rate for each item. It was recognized that these unit rates would need to reflect the prevailing labor rates and materials. Prevailing Government rates for manpower, and construction materials and DOR equipment rates were collected and compared with the prevailing market prices in the District. The cost of equipment includes, owning, running and maintenance and cost for the operation as well. For new items not included in the norms, rates were developed by estimating the inputs of three basic components; labor, material and equipment and applying the respective unit costs of inputs. For manufactured items, the costs were based on local and Indian manufacturers/ suppliers/agents. 12.2 Quantities and Cost Estimates for Road Construction The total estimated cost has been calculated by unit rate of individual items based on rate analysis multiplied by quantities estimated from the design and drawings. The designs were carried out by Software the SW_DTM and SW_ROADS prepared by a local company Softwel (P.) Ltd. The design quantity calculation and total estimated construction cost of the Project Road including VAT and Contingencies have been submitted. The quantity estimate of the proposed facilities and appurtenant structures, has been prepared based on plan, cross sections and profiles that are presented in Drawings. The major works proposed in the project are outlined herewith:

Table 11: Adopted Abstract of Cost for 5.5m width DBST Carriage way and 0.75m width Shoulder both sides exposed incorporating Nepal Urban Road Standard (Draft) with Nepal Road Standard by Department of Roads.

S.No. Items Description Unit Amount for 5.5m Road excluding 1.5m SBST

Remarks














E Total Amount inclusive of Contingencies and VAT (C+D) NRs. 82,300,202.41
