earthquake emergency assistance project kupondole, lalitpur · 2017-08-30 · government of nepal...

Government of Nepal Ministry of Federal Affairs and Local Development

Earthquake Emergency Assistance Project Kupondole, Lalitpur

Central Level Project Implementation Unit (CLPIU)

Contract No.

Survey, Design & Cost Estimate of Khopasi - Dhungkharka -

Chyamrangbeshi - Milche - Borang Road in Kavre District

(Ch 14+055- 18+591.8 Km)

VOLUME I - MAIN REPORT

June, 2017

Submitted by

ERMC (P.) Ltd.

(Environment & Resource Management Consultant)

New Baneshwor, Kathmandu, Nepal

P. O. Box: 12419, Kathmandu

Tel.: 977-01-4483064, 4465863 Fax: 977-01-4479361

Email: [email protected], Website: www.ermcnepal.com

mailto:[email protected]

http://www.ermcnepal.com/

Detail Engineering Survey and Design of Khopasi - Dhungkharka - Chyamrangbeshi - Milche - Borang Road (Kavre)

ACKNOWLEDGEMENT

ERMC would like to extend special gratitude to all the concerned EEAP central Project

coordination Unit and district team, officials of DDC, DTO and especially the local people of the

project area who guided, advised, and cooperated ERMC and joined the survey team and

guided/assisted during conduction of detailed engineering survey work. We also appreciate the

contribution of all the individuals involved in this project works for their kind co-operation and help

at every step of Detail Engineering Survey and Design of Khopasi - Dhungkharka -

Chyamrangbeshi - Milche - Borang Road in Kavre District.


EEAP i

TABLE OF CONTENTS

CHAPTER I – INTRODUCTION………………………………………………………………………… 1

1.1 RRSDP Districts for Implementation ............................... Error! Bookmark not defined.

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

1.3 Scope of Works ............................................................................................................. 1

CHAPTER II – METHODOLOGY………………………………………………………………………. 3

2.1 The Study Team ............................................................................................................ 3

2.2 Desk Study .................................................................................................................... 3

2.3 Identification and Selection of Roads .............................. Error! Bookmark not defined.

2.4 Meetings ........................................................................................................................ 3

2.5 Meeting with Local Level Stakeholders .......................................................................... 4

2.6 Detailed Engineering Survey, Design and Cost Estimate ............................................... 5

2.7 Field Verification of Design / Estimate ............................................................................ 7

CHAPTER III – THE PROJECT………………………………………………………………………… 8

3.1 Project District ................................................................................................................ 8

3.2 Description of Alignment ................................................................................................ 9

3.3 Population Served & Traffic Data ................................................................................. 10

3.4 Potential Area & Growth Centers ................................................................................. 10

3.5 Project Rationale ......................................................................................................... 11

CHAPTER IV – GEOLOGY AND GEOMORPHOLOGY…………………………………………….12

4.1 Geological Study .......................................................................................................... 12

4.1.1 Introduction ........................................................................................................... 12

4.1.2 Regional Geology and Geomorphology ................................................................ 12

4.1.3 Surface Geology ................................................................................................... 12

4.1.4 Slope Stability Condition ....................................................................................... 13

4.1.5 Engineering Geological Mapping .......................................................................... 14

4.1.6 Geological Hazard Mapping .................................................................................. 14

4.2 Construction Material Survey ....................................................................................... 14

Chapter V – HYDROLOGY AND METEOROLOGY………………………………………………... 15

5.1 General ........................................................................................................................ 15

5.2 Rainfall ......................................................................................................................... 15

5.3 Design Discharge ........................................................................................................ 15

5.4 Cross Drains ................................................................................................................ 15

5.5 Side Drains .................................................................................................................. 17

5.6 Selection of Cross-Drainage Structures Type .............................................................. 17

5.6.1 Pipe Culverts ........................................................................................................ 17

5.6.2 Floodway .............................................................................................................. 18

5.6.3 Slab Culverts ........................................................................................................ 18

CHAPTER VI – GEOMETRIC STANDARDS AND DESIGN………………………………………. 19

6.1 Road Classification ...................................................................................................... 19

6.2 Design Standard .......................................................................................................... 19


EEAP ii

6.2.1 Design Speed ....................................................................................................... 19

6.2.2 Geometric Design ................................................................................................. 19

6.3 Horizontal Alignment .................................................................................................... 19

6.3.1 Horizontal Curvature ............................................................................................. 19

6.3.2 Super Elevation .................................................................................................... 19

6.3.3 Maximum Super Elevation Value .......................................................................... 20

6.3.4 Minimum Radius of Curvature ............................................................................... 20

6.4 Widening on Curves ..................................................................................................... 21

6.5 Stopping Sight Distance Sight Distance ....................................................................... 21

6.6 Vertical Alignment ........................................................................................................ 22

6.7 Gradient ....................................................................................................................... 22

6.8 Vertical Curve ........................................................................................................... 23

6.8.1 Summit Curves ..................................................................................................... 23

6.8.2 Valley Curves........................................................................................................ 23

6.9 Road Cross- Section .................................................................................................... 24

6.9.1 Cross Section Design ........................................................................................... 25

6.9.2 Shoulder Width ..................................................................................................... 25

6.9.3 Carriageway Width................................................................................................ 25

6.9.4 Formation Width ................................................................................................... 25

6.9.5 Right of Way ......................................................................................................... 25

6.9.6 Camber ................................................................................................................. 25

6.9.7 Pass Bay .............................................................................................................. 25

6.9.8 Carriageway width at culvert/ bridge ..................................................................... 26

6.9.9 Level of road embankment above hfl .................................................................... 26

6.9.10 Lateral Clearance ................................................................................................. 26

6.9.11 Vertical Clearance ................................................................................................ 26

6.9.12 Cut / Fill Batter Slopes .......................................................................................... 26

CHAPTER VII – ENVIRONMENTAL MITIGATION MEASURES…………………………………. 27

7.1 Consideration Made in Alignment Selection, Survey and Design Phase ...................... 27

7.2 Drainage Outlet Protection Works ................................................................................ 27

7.3 Selection of Slope Protection Work .............................................................................. 27

7.4 List of Some Environment Protection Works ................................................................ 28

CHAPTER VIII – DETAILED ENGINEERING DESIGN……………………………………………. 29

8.1 Design Method ............................................................................................................ 29

8.2 Review & Redesign ...................................................................................................... 29

8.3 Design & Drawings ...................................................................................................... 29

8.4 Horizontal Curve Design .............................................................................................. 29

8.5 Design of Structures and other geometric Features ..................................................... 29

8.6 Pavement Proposed ................................................................................................... 29

8.6.1 Plasticity Index = <6 .............................................................................................. 29


EEAP iii

CHAPTER IX – COST ESTIMATE……………………………………………………………………. 33

9.1 Summary ..................................................................................................................... 33

9.2 Quantity Estimate......................................................................................................... 33

9.3 Rate Analysis ............................................................................................................... 33

9.4 Cost Estimate .............................................................................................................. 33

9.5 Conclusion ................................................................................................................... 33

CHAPTER X – CONCLUSION & RECOMMENDATION…………………………………………… 34

LIST OF TABLES

Table 1.1 : Names of Districts for RRRSDP-2 Implementation……………………………............... Error! Bookmark not defined.

Table 5.1 : Summary of Rainfall Stations…………………………………………………………........15

Table 5.2 : Hourly Rainfall Design Intensities for the Proposed Road……………………………...15

Table 5.3: Hydraulics of Proposed Cross Drains (Pipe Culverts)…………………………………...16

Table 5.4 : Flow Capacity of Proposed Side Drains at Maximum Slope of 10%..............................17

Table 6.1 : Minimum Radius for Horizontal Curve………………………………………………........20

Table 6.2 : Recommended Minimum Widening for Single Lane Road…………………………….21

Table 6.3 : Safe Stopping Site Distance……………………………………………………………….22

Table 8.1 : Summary of the Dynamic Cone Penetration Test (DCP) Test Results Showing CBR Values in Different Sections of Khopasi - Dhunkharkha – Chyamrangbesi Road under RRRSDP-2…………………………………………………………………………………………………………… 32

Table 8.2 : Summary of Pavement Thickness…………………………………………………………Error! Bookmark not defined.

LIST OF FIGURES

Figure 3.1 : Map Showing the road Alignment……………………………………………………….. 10

Figure 4.1 : Regional Geological Map of Panauti-Narayanthan Area (DMG, 1987)…………………. 13

Figure 4.2 : Stereographic Projection of the Rock Mass Exposed along the Road……………….14

Figure 6.1: Single Lane Road with drain in Hill area of District Road – Core Network………….. 24

ANNEXES

Annex 1 : List of Benchmarks

Annex 2 : List of Passing Bay

Annex 3 : DCP Test Data


EEAP iv

ACRONYMS

ADB ADDI BCR BG BS

Asian Development Bank Appraisal Document for Donor Investment Benefit Cost Ratio Building Group Baseline Survey

CE Community Empowerment DDC District Development Committee DFID Department for International Development (UK) DoLIDAR Department of Local Infrastructure Development and Agricultural Roads DoR DoS DPR DRCN

Department of Roads Description of Services Detailed Subproject Report District Road Core Network

DTMP District Transport Master Plan DTO District Technical Office EIA Environmental Impact Assessment EIRR Economic Internal Rate of Return ERMC Environment Resource Management Consultant (the consultant of RRRSDP-2) GDP Gross Domestic Product GoN Government of Nepal ICD Institutional Capacity Development IEE IPDP IRR

Initial Environmental Examination Indigenous People Development Plan Improved Rural Roads

LBFAR Local Body Financial Administrative Regulation LEP Labor-based, Environmentally-friendly, and Participatory (approach) LSGA Local Self-Governance Act MoFALD Ministry of Federal Affairs and Local Development MYRP NGO

Multi Year Rolling Plan Non Government Organization

NPV net present value O&M Operation & Maintenance OFID PCR

OPEC Countries for International Development Subproject Completion Report

PCU PFP

Subproject Coordination Unit Program Financing Plan

PIP

Subproject Program Investment Plan

Subproject PMS Program Monitoring System Subproject

PPTA Subproject Preparatory Technical Assistance

RES RFP

Rapid Environmental Screening Request for Proposal

RIRR RoW

Rural Infrastructure Rehabilitation & Reconstruction Investment Plan of GoN Right of Way

RP Resettlement Plan RRMC Rural Road Maintenance Committee RRMFC RRMMS

Rural Road Maintenance Fund Committee Rural Road Maintenance Management System

RRRSDP SDC

Rural Reconstruction and Rehabilitation Sector Development Program Swiss Agency for Development and Cooperation

SRN Strategic Road Network ToR Terms of Reference VDC Village Development Committee VOC Vehicle Operation Cost ZoI Zone of Influence


EEAP v

SALIENT – FEATURES OF THE PROJECT

1. Name of Project : Khopasi - Dhungkharka - Chyamrangbeshi -

Milche - Borang Road

2. Location

Region : Central Development Region

Zone : Bagmati

District : Kavre

VDC : Dhunkharka VDC and Chyamrangbesi VDC,

3 Major Settlements : Kotthali village of Dhugkharka VDC, and Wai

village and Sano-Durlung village of Chamrangbesi

VDC

4 Population served : 13211

5 Terrain : Hilly

6 Classification of Road

Classification : District Core Road Network

Existing Surface : Earthen

Proposed Standard : Gravel (L=0.572 km) / cobble (L=3.965 km)

7 Road Alignment

Starting Point : Bhanjayang of Chamrangbesi VDC

Ending Point : Besi Gaun, Chyambrangbasi VDC

Length : 4.537 km

DTMP Code : 24DR011

8 Cross Section

Right of Way : 10m either Side

Formation Width 6.25 m including drain

Roadway Wdth : 5.25 m

Carriageway Width : 3.75 m

Shoulder Width : 0.75 m either Side

9 Earthwork

Cut Volume (Cum) : 147053.73 cum

Fill Volume (Cum) : 4252.38 cum

10 Retaining Structure

Gabion Wall (Cum) : 3811.00 cum

Cement Masonry Wall : 2760.02 cum

11 Drainage

Drain 5629.28 Rm

Pipe culvert : 18 Nos

12 Project Cost

Overall Total with VAT and

Contingency

: NRs 106,880,708.02

Cost Per Km with VAT and

Contingency

: NRs 23,557,572.85

Cost Per Km without VAT : NRs 18,696,486.39


EEAP vi

EXECUTIVE SUMMARY

This report is the findings of detailed engineering survey and design of Khopasi - Dhungkharka -

Chyamrangbeshi - Milche - Borang Road (Kavre)” that was carried out for improvement and

upgrading of road stretch that connects the different settlements of Khopasi, Chalalganeshthan,

Dhungkharka and Chyamrangbeshi VDCs with Banepa - Panauti feeder road and Arniko highway

and ultimately joins with district headquarter Dhulikhel and Kathmandu valley.

This road is designed for upgrading to gravel standard and other proposed intervention comprises:

Widening of narrow section to NRRS 2055 (With revision on September 2012) standard

Improvement of steep and uneven gradient

Provision of passing bays

Improved drainage system with lined drain and adequate cross-drainage structures

Upgrade the road geometry to minimum design standard of DoLIDAR; and

Minimizing Environmental hazards

The total length of road is 4.537 km. The road alignment is the continuation of first part of the same

alignment Khopasi - Dhungkharka - Chyamrangbeshi - Milche - Borang Road (Kavre) (14 Km) and

starts at Bhanjyang of Dhungkharkaha passes through different settlements of Khopasi,

Chalalganeshthan, Dhungkharka and Chyamrangbeshi VDCsand reaches to Sanodurlung,

Chyambrangbasi VDC.

This road will provide access to market, education institutions, and Health center and government

service offices

The Consultant has conducted the detail survey work of proposed road with total station using

digital terrain model. Walkover survey has been conducted to confirm the feasibility of road. Local

peoples including district DTO team are consulted prior to commencement of work.

Existing road has been followed as far as possible while fixing the alignment; however, these will

be shifted in some places especially at hair-pin-bends to maintain the geometric design

parameters. As far as the topography allows the ruling longitudinal gradient has been followed.

Only in exceptional cases where the alternative alignment is difficult and not justifiable, the gradient

is adopted to 12% and even more keeping view of resettlement limitation and other social reasons

and to escape from unfeasible cut/fill.

The road is designed to all weather gravel standard of District Core Road Network class with

general width of 5.25 m along with 3.75m carriageway including 0.75 m shoulder on either side

and with vehicle-passing zone at intervals as proposed in the design standard.

In order to manage the surface run-off lined drain is proposed with cross-drainages at frequent

interval focusing to be located at vertical intersection valley points. Consideration is given to safe

discharge of the drainage outlets in natural gullies. Type of crossings has been determined keeping

view of nature and characteristics of gullies, river, stream and spring.

Unnecessary heavy cut/fill has been avoided as far as possible; however, this could happen to

some extent especially in hair-pin bends, where the combined effect of design grade limitation and

abrupt change of topography contour could induce such consequences and at places of high &

Nepal Rural Road Standard (2055) with second revision of September 2012 of MoFALD and

DOLIDAR has been followed during detailed engineering survey and design. So far, the

construction concerns, environment–friendly approach adopted in design.


EEAP vii

The Consultant has tried their best knowledge, lesson learnt and expertise to cover all aspects of

road design in mountainous terrain and to produce a quality design report with optimal economical

and environmental consideration.


EEAP 1

CHAPTER I – INTRODUCTION

This detailed engineering survey, design and cost estimate report has been produced as result of field investigation, topographical survey along with

1.1 Objectives

To achieve the program goal of reduce the poverty the program will continue and strengthen the

overall objectives to improve connectivity, enhanced economic and employment opportunities and

to ensure increased access to markets and social services for rural communities.

1.2 Scope of Works

The consultant shall prepare Detailed Project Reports (DPR) of each Road Subprojects.

Preparation of Detailed Engineering Survey, Design and Cost Estimate of Individual Road

Subprojects is one of major part of Detailed Project Report Preparation (under Part A of 2.2 of

Scope of Consulting Services). Following are the task under engineering report:

Detailed field investigation including topographical survey, geological observation, hydrological

study &incorporating meteorological secondary information, slope stabilization features, drainages

patterns, and other features for road design.

Cross-drainage requirements will be assessed for proposing new structures for bridges, culverts,

and causeways as appropriate or improvements will be recommended for structurally unsound

structures.

Engineering surveys will be done following the standard engineering practices with horizontal and

vertical controls and benchmarking with all details necessary for a detailed design of roads.

Material availability surveys will also be conducted for record. Local rates for construction, of

various items, local and imported materials, transportation charges, etc., will be enquired and

established as per the prevailing market rates and labour wage rates are to be confirmed from

district rates for cost estimating purpose.

Computer aided software designs will be done for road designing. However manual designs in

some cases can be done.

The detailed designs will be done or prepared by the Consultant following the DoLIDAR’s Rural

Road Design Standards.

Detailed and standard drawings will be also prepared as mentioned in the DoLIDAR Technical

Guidelines.

The designs and drawings will consist of the location map and layout, design profile, design cross-

section plan, other structural detailing and drawings and standard/typical drawings.

Engineering technical specifications for each work item will be written taking into account relevant

standard specifications in use in the country and elsewhere for similar works and in accordance

with the Codes of Practices.

The detailed cost estimate will be prepared using the calculated quantities and unit rates, derived

from standard applicable District Rates and DoLIDAR Work Norms.

Detailed Subproject Report (DPR) will be prepared following the agreed Table of Content.


EEAP 2

Detailed economic analysis of individual road subprojects will be carried out and presented in the

DPR.

Contract packaging will be suitably done as agreed with the Client for all subprojects, and

respective bidding documents will be prepared following the DoLIDAR practices and frameworks.

Similarly engineering subproject implementation schedules will be prepared.


EEAP 3

CHAPTER II – METHODOLOGY

2.1 The Study Team

The study team of Consultants for detailed engineering comprised a Road Expert (Team Leader),

one Social Specialist, one Environmental Specialist, one Resettlement Specialist, Road Engineer,

one Bridge Engineer, one Geo-Technical Engineer, one Geologist, one Hydrologist and one

Transport Economist.

In addition to the above mentioned core team, the Consultants had fielded special survey team for

conduction of detailed engineering survey and design of road sub-projects. Furthermore, other

necessary human resource and all required logistics was mobilized for the study of road in terms

of engineering feasibility, social viability, environmental sustainability and economically beneficial.

2.2 Desk Study

The Consultant collected documents, drawings, study reports, maps, walkover survey report and

existing DTMP to acquire and extract key information for conduction of detail engineering study of

the selected alignment route. The Consultant had studied all these documents prior to field

movement to perform detail alignment survey.

Following activities were carried out during desk study:

Studied the maps and previous reports that indicated the route alignment.

Collected all relevant guidelines, norms, handout, specification and maps required for desk

study.

Nepal Rural Road Standard (NRSS 2055) and DoLIDAR Norms & Specification has been

studied and referred for adoption of design standard and specification.

Collected and referred existing DTMP of district road core network and its priority ranking.

Collected relevant geological map to acquire geological/geotechnical feature of road

alignment.

Study has been made to find out the possible environmentally sensitive areas from where

the alignment passes through

2.3 Meetings

Meeting – I: Prior to commencement of feasibility/detailed engineering study a meeting was

organized on August 1, 2013, in the Project Coordination Unit (PCU) Office at DoLIDAR.

Discussions were held on work delivery, understanding of program requirements and

responsibilities of the Consultant’s team members in general, and procedures and time frame

management in particular.

Meeting – II: Likewise, on August 5, 2013, orientation meeting as a kick-off point for

feasibility/detailed engineering was held among the team members of the Consultant. Discussion

on how to move forward to accomplish the task in a systematic manner keeping in view of the

limited time was done. Also, the Team Leader drew attention of the individual professionals for

carrying out the duties and responsibilities as prescribed by the ToR of the Program Agreement

for consultancy services. A need of management support system, communication, and

coordination was expressed. The participants in this meeting were:

Meeting – III: A Meeting was arranged by ERMC on December 08, 2013. The following points

were highlighted for action:


EEAP 4

Collect information about household, family/settlement and water supply along the road

alignment.

For the environmental part, only IEE can be done (no need to do EIA being rural roads).

It should be differentiated beforehand what costs to put in IEE part and what in contractor

part.

Include bio-engineering, demand of the community infrastructures and their costs in the

BoQ.

Only genuine works that can be achieved should be included in the report. No exaggeration will

be entertained.

Since all kinds of implementation plans (like Social Action Plan, Resettlement Plan, Environmental

Plan, Indigenous People Development Plan) are done for the same road (and naturally it belongs

to the same groups of people), utmost care should be taken so that there is no duplication.

Endangered human groups (for example, Majhi, Chepang, Raute, etc.) should be addressed more

than the other groups.

Utmost care must be taken while analyzing survey data and reports should be attractive,

meaningful and precise.

Orientation to Field Detailed Engineering Survey Team

On November 24, an orientation and interaction session was organized at RRRSDP Office of the

Consultant by the TL in presence of PD and other senior road designers and all road and bridge

survey teams being mobilized in 18 districts. They were thoroughly briefed about survey works

with specially prepared ToR for field works for uniformity, accuracy and quality outputs.

Key points discussed:

Topography Survey and Details, Survey Codes, D-Cards, Total Station Closing & Error

Distribution, National Grids, GPS, DTM, CAD, DoLIDAR Norms, Recommended Gradients, First

Meeting with DTO/DDC and Local Concerned, Records and Report, Meeting Minuting, DoLIDAR's

Letter of Jestha 1, 2070 and Letter from RRRSDP Consultant to DDCs, ID Cards, Information from

Field, etc.

2.5 Meeting with Local Level Stakeholders

Local people were contacted prior to conduction of detailed engineering survey. Meeting with

DTO/DDC was also held regarding the plan of the team for the study of road sub-projects selected

by districts.


EEAP 5

2.6 Detailed Engineering Survey, Design and Cost Estimate

I. Field Team Mobilization

Engineering team comprising of highway Engineer, geologist, Environmentalist and sub-

engineer/senior surveyor and local supervisor with other sector specialists had been mobilized in

field for detailed survey works equipped with necessary survey equipment and accessories.

Prior to conduction of detail survey Results of previous feasibility/walkover surveys were verified

II. Field Survey Team Composition

Following are the member of survey team:

Deepak ParajuliTeam Leader

Sanjaya YadavS. Surveyor

Manjit PokhrelSurveyor

Babin ShresthaHelper

III. Topographic Survey

Strip survey method was used in the field which included fixing of the base stations and taking

details 15m either side for preparing a topographic map of the road strip.

Topography survey is carried out in adequate details and accuracy to prepare exact DTM of the

road alignment in 1:1000 scales. Horizontal and vertical control points are established by

monument of concrete pillar at an interval of 500m.

Initially traverse survey was carried out with high accuracy (1:70,000 to 1:148,000.)to establish

traverse station and other permanent control points. Topographical details were carried out from

these traverse stations to attain accuracy at higher level.

Close traverse method was applied for horizontal traversing.

Establishment of Control Points / Benchmarks: Permanent monument has been installed as

benchmarks (approx. size 15 cm x 15 cm x 60 cm) with 1:2:4 cement concrete nails embedded as

per the DoLIDAR standards at intervals not exceeding 500 m according to site condition. The

Control point (size 10 cm x 10 cm x 45 cm) with 1:2:4 concrete is installed at 250 m interval on an

average. Description cards are prepared for each benchmark / control point with three reference

points.

Traverse and Fly Leveling: The coordinates of control points is presented in NEZD (Northing,

Easting, Elevation and Description) format along with point number and remark. Closed traverse

survey is carried out to confirm the control point coordinates. All traverse angles and distances

shall be double checked with reciprocal observations. Traverse and level shall be calculated at

the site itself for accuracy and quality control and data validation. If reasonable accuracy

(1:10,000) is not achieved, the traverse shall be repeated.


EEAP 6

Centerline and Cross Section Survey: Centerline of road is marked using Abney level by the

method of chainaging and pegging which then followed by Total station survey.

Cross sections survey has been carried out at intervals not exceeding 10 m. Where topographic

features such as ridges and valleys are encountered, additional cross sections taken.

The cross sections generally extend to 15 m either side of road centerline and extended further

whenever site demands.

Enough points taken at each cross-section or for each string to cover full width of the road including

roadside feature, side drain, toe of cut/fill slope retaining wall, cross drainage structure etc.

Topographical survey also included individual building, utilities (water supply, electricity, telephone

poles etc.), landslides, canals, footpaths, temples, Kushmas, drainages, cross structures, retaining

structures, land use patterns and other information such as fences etc.

At bridge side the bank lines lowest water level HFL, direction and distribution of flow taken.

Digital Terrain Model: DTM (a digital representation of ground surface topography or terrain) has

been carried out using SW–DTM or other acceptable software and verified in field. All feature lines

and configurations of existing features shall be completed in AutoCAD compatible maps D-Cards

of BM and BL, field sketches and raw downloaded data shall be submitted together with DTM.

Check of data consistency, error distribution and adjustments shall be clearly documented. All data

and records have been submitted in digital format.

IV. Hydrological Study / Cross drainage Survey

Cross-drainage requirements has been assessed with identification of type requires such as

bridges, culverts, and causeways as appropriate

V. Geological Studies

Geological observation inclusive of soil type, geology and geomorphology, slope stabilization,

vegetation, land erosion situation, landslide prone areas, gully formation, and other features have

been conducted for proper design of road.

VI. Alignment Description / Inventory of Land use/Public Infrastructures

Alignment descriptions for road and other necessary features are properly recorded in detail.

Inventory of public infrastructure and land use pattern were taken with locations

VII. Material Availability Surveys

Material availability survey has been conducted to acquire the information on construction material.

Local rates for construction, of various items, local and imported materials, transportation charges,

etc., enquired and district rates collected for cost estimating purpose.

VIII. Design Drawings:

The detailed engineering design and drawings is based on the data collected during detailed

engineering survey.


EEAP 7

The detailed designs have been done or prepared by the Consultant following the DoLIDAR’s

Nepal Rural Road Design Standards 2055 and detailed and standard drawings are prepared as

mentioned in the DoLIDAR Technical Guidelines.

The designs and drawings consist of the design profile, design cross-section plan, and other

standard/typical drawings.

Engineering technical specifications for each work item will be written taking into account relevant

standard specifications.

IX. Detailed Cost Estimate

The detailed cost estimate has been prepared using the calculated quantities and unit rates,

derived from standard applicable District Rates and DoLIDAR Work Norms.

Contract packaging will be suitably done for all subprojects, and respective bidding documents will

be prepared following the DoLIDAR practices and frameworks.

2.7 Field Verification of Design / Estimate

After the production of design drawings and cost estimate of road sub-project, joint field verification

from DTO, EEAP and Consultant representative is done to verify the result of survey, design works

with the existing ground reality and to assess whether the proposed retaining and drainage

structures are appropriate as per the field condition.


EEAP 8

CHAPTER III – THE PROJECT

3.1 Project District

Kavre District is situated in the south-east part of Bagmati zone of central development region.

The political boundary of the district comprises of Sindhuli and Ramechhap in east,

Sindhupalchowk in north, Lalitpur and Bhaktapur in west and Makawanpur in south.

The district lies between 27o 20’ to 27o 45’ North latitude and 85o 24’ to 85o 49’ East longitude in

Mahabharata range. The elevation of the district is 300 meter to 3018 meters from the mean sea

level.

The total population of the Kavreplanchowk district is 368,165.00 as per the latest census.

Most of the parts of the districts lies in the Mahabharata range and have steep slope. 52.5percent

of land have steep slope, 41.3 percent of land have moderate slope, 5.1 percent consists of plain&

valley and 1.1 percent land is covered by gravel and rivers. The average temperature of the district

varies from minimum 10C to maximum 31C. The average annual precipitation is 1582ml The major

rivers of the Kavreplanchowk districts are Sunkoshi, Indrawati, Roshi, Bagmati.

The remote parts are lagging of proper transportation facilities. Dhulikhel Municipality, Banepa,

Panchkhal valley, Panauti are the key growth centres. There are three municipalities in the district

namely Dhulikhel, Panuti and Banepa. 25.9 percent of the land is used for the agriculture purpose

and 28.2 percent of lad is forest.

The district inventory identified just over 1723.70 km of roads, including 153.97 km of strategic

roads and 181.77 km of Urban roads. As per DTMP 38 rural roads with a length of 681.60 km were

identified as district road core network (DRCN), and the remaining 708.10 km were classified as


EEAP 9

village roads. The existing DRCN roads link up 87 of the VDC headquarters. Almost of the DRCN

roads are earthen fair weather roads.

3.2 Description of Alignment

The proposed Khopasi - Dhungkharka - Chyamrangbeshi - Milche - Borang Road is located in

South - West part of Kavre district. The road alignment is the continuation of first part of the same

alignment Khopasi - Dhungkharka - Chyamrangbeshi - Milche - Borang Road (Kavre) (14 Km) and

starts at Bhanjyang of Dhungkharkaha passes through different settlements of Khopasi,

Chalalganeshthan, Dhungkharka and Chyamrangbeshi VDCs and reaches to Sanodurlung,

Chyambrangbasi VDC.


EEAP 10

Figure 3.1 : Map Showing the road Alignment

The total road length of road is 4.591km. There is existing track opened with varying width of 3.50

m to 4.30 m. The existing road surface is earthen in general.

The DTMP code of this road as per District Transport Perspective Plan is 24DR011

3.3 Population Served & Traffic Data

Presently the total population to be served by this road is 13211 benefitting people of Chalal

Ganeshthan, Dungkharka, Chamrangbesi and Milche. The present traffic number is 78 PCU with

87 vehicles per day.

3.4 Potential Area & Growth Centers

Khopasi and Dhungkharka are potential market of this alignment. The ZOI area is very popular for

milk production. Local people will get easy access to transport their product in milk chilling center

located in Khopasi –Panauti road. The hills have potential of developing trekking, hiking and other

type of tourism.


EEAP 11

3.5 Project Rationale

The rationale for upgrading of this road is as followings:

This road joins Khopasibazaar of Panauti Municipality, Khadka village and Patikharka village of

Chalalganesthan VDC, Parthali Bhanjyang, Goldung village and Kotthali village of Dhugkharka

VDC, and Wai village and Sano-Durlung village of Chamrangbesi VDC with market centers Panuti,

Banepa and district headquarter Dhulikhel and eventually country's capital Kathmandu.

Another feature of this road is it will provide access to villages of neighboring Makawanpur district

in future.

The road will play a vital role to change the traditional subsistence agriculture in to commercial

farming and hence will increase cash crop production and livestock development and dairy farming

in the zone of influence area by improving access to densely populated market centers.

Improvement and upgrading of the road is expected to help the people of the area to receive better

education and quick access to medical facilities. Government’s other services will also be delivered

better.

It is expected to reduce the travel time considerably and thus people can utilize the saved time for

other productive works.

The proposed road is expected not only to be an excellent facility to link several ecological, cultural

and demographic zones of the district but it will also open new possibilities for entrepreneurs with

new visions and plans. Furthermore, the road upgrading will use local labor that will generate

employment to local people and minimize emigration to other major cities and abroad for search

of work. Consequently, local people will get long-term benefit, which will boost up their economic

status within the road corridor and adjoining area.


EEAP 12

CHAPTER IV – GEOLOGY AND GEOMORPHOLOGY

4.1 Geological Study

4.1.1 Introduction

A geological survey has been carried out along the 18 km long alignment of the Khopasi-

Dhungkharka-Chyamrangbesi-Milche-Botang Road, an important road for connecting southern

part of Kavrepalanchowk districts.

4.1.2 Regional Geology and Geomorphology

This road follows the rocks of the Midland Group of the Lesser Himalaya. The Midland Group is

comprised of Tistung Formation; Sopyang Khola, Chandragiri Formation, Sarung Khola Formation,

Markhu Formation of the Kathmandu Group. The road passes on the rocks of the Tistung

Formation, Chadragiri Formation, Sopyang Formation, Sarung Khola Formation and Markhu

Formation. The Tistung Formation is composed of quartzite as well as phyllite. The Chandragiri

Formation is comprised of limestone and Sopyang Formation is represented by thick bedded slate

and limestone. The Markhu Formation is composed of thick bedded limestone and schist (Figure

1). The road alignment starts at Khopasi Bazaar and ends at Chyamrangbesi flows the rolling

topography. The maximum altitude of the area is at Parthali. The road crosses the Salandu Khola,

Patne Khola. These tributaries are drained out in the Rosi Khola at Khopasi and not perennial

river. The topography of along the road alignment is gentle to steep slope.

Initially, the road alignment starts from Khopasi and follows the Salandu Khola valley and climbs

from Ganeshthanchalal to Parthali then the road climbs down to Gelung after Gelung the road

alignment very gently climb up upto Chamrangbesi. The road also passes through the rocky terrain

as well as colluvial and alluvial deposits. The road alignment passes through wet and dry cultivated

land, grassland, forest. Road passes villages such as Patikharka, Parthali, Gelung and

Chyamrangbesi. This road alignment crosses the Rosi Khola Fault. The fault extends east-west in

direction.

4.1.3 Surface Geology

Along the road section, the rocks of the limestone of the Chandragiri Formation, Intercalation of

phyllite and quartzite of the Tistung Formation, marble and schist of the Markhu Formation.


EEAP 13

Figure 4.1 : Regional Geological Map of Panauti-Narayanthan Area (DMG, 1987)

4.1.4 Slope Stability Condition

Some cut slope failures are observed in colluvial deposits and a few are in rock. The main causes

of occurring failures are rock weathering, precipitation, surface water condition, groundwater and

undercutting slope by road cutting. Almost all failures are occurred after opening of the road.

Between Khopasi to Parthali village, some places, there is possibilities wedge failure which is seen

in limestone quartzite of the Chandragiri Limestone and most places in the rocky area has good

slope stability. There is possibility of scouring by the Salandu Khola at the valley side in alluvial

deposits. The stereograph shows relation between natural hill slope and foliation plane is parallel

so high possibility of failure. The wedge formed by joints (J1 and J2) with foliation plane is very

unstable (Figure 2).

Between Parthali and Chyamrangbesi village, major length of the road passes on the alluvial

deposits of the Ladkhu Khola so there is high possibility to occur the bank erosion. The stereograph

shows relation between natural hill slope and foliation plane is opposite so very less possibility of

occur the failure and same phenomenon can be seen along the joint (J2). The wedge formed by

joint (J1,) with foliation plane is very stable but with joint (J2) is unstable (Figure 5.2 and Table

5.2).

Besishahar-Sattale Road


EEAP 14

Figure 4.2 : Stereographic Projection of the Rock Mass Exposed along the Road

4.1.5 Engineering Geological Mapping

This complete section of the road is about 18 km in length. Between this chainage, the road passes

on the northeast face and very gently climbs up from Khopasi to Parthali and follow the left bank

of the Salandu Khola from Patikharka about 5 to 10 m above from the riverbed. The road alignment

between this chainage is on alluvial deposits and some part on colluvial deposits and rocks.

Thickness of colluvial and alluvial deposits range from 3 to 5 m. The hydrological condition of the

road alignment is dry and some places wet to dry. The land use pattern is dry cultivated land, forest

and grassland. Some cut slope failures including landslides are found along the road alignment.

These failures are developed in the rocks and colluvial deposits. The bedrocks of the Tistung

Chandragiri and Sopyang Khola Formation are exposed along the road alignment. The failures

occurred along the road can be mitigated by trimming of cut slope, applying bioengineering as well

as drainage and arrangement of the gabion wall. The road alignment along this section crosses

the Salandu Khola.

4.1.6 Geological Hazard Mapping

Soil and rock hazards along the road alignment are low to medium. The low hazardous soil covers

very little area comparing with area of the medium hazardous of soil. The main influencing

components for occurring of the medium soil hazard are soil depth, land use pattern and the soil

slope. Rock hazard in this section is low to medium with major area covered by the low hazard.

Structural, geomechanical (lithological) and seismo-tectonic are the main components for

occurring of the low hazardous area in this section. The slope stability of this section is good so

necessity for realigning any of the subsection is not envisaged on account of geological

consideration.

4.2 Construction Material Survey

The stones required are quarried at road side of project road. The road alignment consists of

deposit composed of and boulder mixed soils. Moreover, the stones, gravel and sand are also

easily available on Salandu Khola.

Other construction material like cement and steel can be procured from Panauti bazaar 3 km from

Khopasi and Banepa 7 km far from Panauti


EEAP 15

CHAPTER V – HYDROLOGY AND METEOROLOGY

5.1 General

The main purpose of the hydrological studies is to evaluate the discharge across and along the

proposed road alignment due to monsoon rainfall so that appropriate drainage structures can be

selected and designed. The type, size, span and shape of cross and side drains are then fixed

according to the corresponding design discharge.

5.2 Rainfall

The proposed road lies in Kavrepalanchok District. Rainfall stations located in this district are

presented in Table 5.1. Mean Annual Rainfall (MAR) and Monsoon Wetness Index (MWI) at these

stations are obtained from “Hydrological Estimations in Nepal”, DHM, 2004. About 80% of rainfall

occurs in monsoon, which starts around the middle of June and continues until the end of August.

Table 5.1 : Summary of Rainfall Stations

Station Name Index

No.

Latitude

Longitude

Elevation

(m)

MAR

(mm)

MWI

(mm)

MANDAN 1020 27 42 85 39 1365 1176 963

DOLAL GHAT 1023 27 38 85 43 710 1119 883

DHULIKHEL 1024 27 37 85 33 1552 1554 1245

PACHUWAR GHAT 1028 27 34 85 45 633 962 726

PANCHKHAL 1036 27 41 85 38 865 1236 963

KHOPASI(PANAUTI) 1049 27 35 85 31 1517 1377 1056

Hourly rainfall design intensities of different return periods at these rainfall stations are obtained

from “Maximum storm flood for the design of road structures of Nepal”, Prem Chandra Jha, Ph.D.

Dissertation, Moscow, 1996 and presented in Table 5.2.

Table 5.2 : Hourly Rainfall Design Intensities for the Proposed Road

Return Period, T (years) 2 5 10 20 50 100

Hourly Rainfall Design Intensity (mm/min) 0.45 0.64 0.78 0.93 1.11 1.26

5.3 Design Discharge

The design discharge for the hydraulic design of cross and side drains of this road has been

estimated by “PCJ 1996” [Maximum storm flood for the design of road structures of Nepal]. PCJ

1996 uses hourly rainfall design intensity (Table 5.2). Flood discharges from unit area (1 sq.km)

for different return periods, estimated by this method are presented in Table 5.3.

5.4 Cross Drains

Cross drains are mainly designed to pass the stream flows. However, in some cases the cross

drains are provided to divert the flows coming from side drains. Following steps are followed for

locating cross drains:

Identifying stream points and valley curves in topographical map

Verifying these locations during field visit and survey

Locating finally after study of designed plan and profile of the road


EEAP 16

Following design criteria are adopted for the design of cross drains after hydrological analysis:

Design flood frequency: 20 years

Design intensity: 0.93 mm/min

Design flood: 6.6 m3/sec/km2

The design discharge for a cross drain is a high flow corresponding to the selected return period.

In order to economize on construction costs, frequency of flood is selected for return periods,

depending upon the importance of the structure. For this road, it is recommended to design the

cross drains for 20 years return period flood.

The drain size varies based on the design discharge. The design discharge for each drain is

different. It means there will be many sizes of cross drains in a road. For crossing of small streams,

rivulet and springs not carrying debris pipe culvert is good option. It is not practicable even not

economical to construct pipe culvert of many sizes. Hence it is decided to use pipe culverts of 60,

90 and 120 cm for crossing the drains. By experience, the 60 cm diameter pipe is not

recommended for cross drains because of choking and clogging by sediment and debris coming

from upslope of mountain catchments. However, it can be used for crossing of irrigation channels,

road intersection and flow with low discharges. The 120 cm diameter pipe should also be avoided

due to the difficulties of handling and transporting.

In most of the places where seasonal waterways occur in the monsoon and for flash flood, stone

or concrete causeways are recommended.

The hydraulics of pipe culverts is worked out in Table 5.4. Maximum flow capacity and velocity are

determined at a suitable head. The design discharge of a crossing is compared with flow capacity

of a pipe and then size is fixed from standard pipe sizes.

Table 5.3: Hydraulics of Proposed Cross Drains (Pipe Culverts)

CD type

Size

(m)

Full

flowing

area, m2

Max.

design

slope, %

Length

of

CD, m

Max.

Head

loss, m

Friction

coeff.(f)

Max.

Velocity,

m/sec

Max.

flow,

m3/sec

Pipe culvert 0.60 0.28 3 6 0.18 0.05 2.66 0.74

Pipe culvert 0.90 0.63 3 6 0.18 0.05 3.26 2.05

Pipe culvert 1.20 1.12 3 6 0.18 0.05 3.76 4.21

Table 5.4 gives an idea of maximum flow capacity and velocity of proposed pipe culverts so as to

define the proper size of the culvert based on design discharge coming to a culvert. The maximum

design slope for these culverts is assumed as 3% so as to create self-flushing velocity. Table 5.4

shows the full flow capacities, head losses and the design slopes for different pipes. Head losses

are calculated by Darcy - Weisbach formula for pipe flow. The coefficient of friction (f) for concrete

pipe in this formula is assumed as 0.05. The maximum velocity at exit point for all size of pipes

shall be maintained by providing an apron. The length of pipe in average is assumed to be 6 m.

For medium size streams where flow more and carrying boulders, pebbles and gravels and span

is up to 6 m, box or slab culvert are recommended. The actual span of these culverts is fixed

according to field survey. For larger streams bridges of suitable span based on field survey are

recommended.

The list of proposed cross drains is provided in Annex 4.


EEAP 17

5.5 Side Drains

Side drains are recommended for catching the flows from road surface and upside adjoining areas.

In some stretches side drains exist but most of the side drains will be occupied by new design

width of the road and hence new side drains are proposed along the full length of this road. The

design discharge for a side drain is a high flow corresponding to the selected return period. In

order to economize on construction costs, frequency of flood is selected for return periods,

depending upon the importance of the structure. For this road, it is recommended to design the

longitudinal side drains for 5 years return period flood. Following design criteria are adopted for

the design of side drains after hydrological analysis:

Design flood frequency: 5 years

Design intensity: 0.64 mm/min

Design discharge: 1.9 m3/sec/km2

Table 5.5 shows the maximum flow capacity and velocity of side drains at maximum longitudinal

slope of 10% and having full flowing area. The side drains must follow the longitudinal slope of the

road and in most of the cases hill road has a maximum slope of 12%. Cross sections of proposed

side drains types (A, B & C) are presented in Figure 5.1.

Table 5.4 : Flow Capacity of Proposed Side Drains at Maximum Slope of 10%

Drain Type b, m d, m A, m2 P, m R, m n S V, m/s Q, m3/s

Tick Drain [A] 0.8 0.3 0.12 1.154 0.104 0.016 0.10 4.34 0.52

Tick Drain [B] 0.8 0.45 0.18 1.368 0.131 0.016 0.10 5.07 0.91

Trapezoidal Drain [C] 0.45 0.45 0.2025 1.31 0.155 0.016 0.10 5.66 1.15

As the design discharge is between 1.5 to 3 m3/sec/km2 with medium intensity of rainfall, tick type

side drain of concrete masonry [Type B] having medium draining capacity is recommended for this

road. It is also recommended that the length of side drain should not be more than 300 m. Hence

a cross drain of 90 cm diameter is proposed to cater the discharge of side drain at 300 m interval.

Figure 5.1 Proposed types of Side Drains

5.6 Selection of Cross-Drainage Structures Type

5.6.1 Pipe Culverts

Pipe culverts are proposed in areas where the discharge is concentrated and at intersection points

of vertical gradients. Vehicular access to the construction site is necessary for transportation of

the pipe.

The minimum culvert size proposed is 600 mm diameter. The minimum size was selected to lessen

the risk of the blockage and make it easier to clear blockages once they occur. The maximum size


EEAP 18

was selected in consideration of the difficulties of handling and transporting larger size pipes during

construction.

5.6.2 Floodway

In consideration to the road design standards floodways will be preferred over large culverts.

Floodways will be cheaper to construct and will be more likely to accommodate flood events

outside the 10-year design period without damage.

5.6.3 Slab Culverts

Slab culverts will be preferred for cases where the topography would make construction of a

floodway difficult.


EEAP 19

CHAPTER VI – GEOMETRIC STANDARDS AND DESIGN

Geometric design standard of Nepal Rural Road Standard (2055) with first revision of September

2012with District Road Core Network class have been followed while carrying out detailed

engineering survey and design of RRRSDP-2 roads proposed for improvement, upgrading and

new construction. Work Norms and specification of DoLIDAR in general and Norms for Rate

Analysis as per Standard Specification for Road and Bridge Works for specific items is followed

for cost analysis of sub-projects and preparation of contract packages.

6.1 Road Classification

Project roads fall under the category of District Road Core Network as per Nepal Rural Road

Standard -2055 (Revised September 2012) as it connects village headquarter with strategic road

network and District headquarter.

6.2 Design Standard

6.2.1 Design Speed

The sight distance, radius of horizontal curve, super elevation, extra widening of pavement, length

of horizontal curve and the length of vertical curve (summit and valley) depend on the design

speed, which in turn depends on class of road and nature of terrain. According to the design

standards, the design speed for hill terrain is 25 km/h and minimum is 20 km/hr.

6.2.2 Geometric Design

The technical standards are set considering minimum initial investments with the scope for gradual

upgrading. The roads can be upgraded in a compatible manner as the traffic volume increases

and availability of resources justify additional inputs.

The design standards / parameters adopted for the sub-project follow DoLIDAR Rural Road Design

Standards, DRCN.

6.3 Horizontal Alignment

6.3.1 Horizontal Curvature

The purpose of introducing curves is to deflect a vehicle traveling along one of the straight, safely

and comfortably, through the angle (deflection angle), to enable it to continue its journey along the

other straight.

A horizontal curve serves for change in direction to the centerline of a road and safe turning to the

vehicles in horizontal plane.

6.3.2 Super Elevation

Super elevation is provided to maintain the design traffic speed at a given radius.

Coefficient of Lateral Friction (f)

The value of the coefficient of lateral force depends basically upon vehicle speed, type and

condition of road type and surface as well as the condition of tyres the factor affecting the


EEAP 20

coefficient(I) 'f' is adopted as per IRC recommendation i.e. if the value of 'f' = 0.15, is adopted, the

passenger shall not feel discomfort.

6.3.3 Maximum Super Elevation Value

In plain terrain, non-motorized vehicles travel with high centre of gravity, so the maximum value of

super elevation shall be limited to the following values;

Terai 7%

Hill 10%

The designer should aim at providing flatter super elevation but it should not be less than the

camber.

Super-elevation is defined as the raising of the outer edge of the road or track along curves. It will

reduce effect of radial force on the vehicle.

6.3.4 Minimum Radius of Curvature

On a horizontal curve, the centrifugal force is balanced by the effects of super elevation and side

friction. The following formula fulfills the condition of equilibrium

Where,

V = Vehicle Design Speed, km/hr

R = Radius, m

e = Super elevation ratio, meter per meter.

f = Coefficient of side (lateral) friction between the vehicle tyres and pavement. A constant

value of coefficient of side friction is adopted at 0.15.

The recommended minimum radius value is tabulated in Table below

Table 6.1 : Minimum Radius for Horizontal Curve


EEAP 21

For the section of the road where difficult site conditions are in predominance, the minimum radius

of horizontal curves adopted are ruling minimum of 15 m and absolute minimum radius of 12.5 m

is provided.

6.4 Widening on Curves

At sharp horizontal curves, it is necessary to widen the carriageway to provide safe passage of

vehicles. Widening is dependent on curve radius, width of carriageway and type of vehicle (length

and width). Widening has two components: (1) mechanical widening to compensate for the extra

width occupied by the vehicle on the curve due to tracing of the rear wheels, and (ii) psychological

widening vehicles in a lane tend to wander more on a curve than on a straight reach.

In single lane roads, the outer wheels of vehicles use the shoulders whether on the straight or on

a curve. Therefore, use of the mechanical component of widening should be sufficient on its own.

For single lane roads, only mechanical widening is required for low traffic speed.

We= (L2/2R)

Where, We= extra widening

N= number of traffic lanes

L= length of wheel base (6.1 m)

R= radius of curve

The recommended increase in width is given in Table below

Table 6.2 : Recommended Minimum Widening for Single Lane Road

6.5 Stopping Sight Distance Sight Distance

Visibility is an important requirement for the safety of travel on the roads. For this it is necessary

that sight distance of adequate length should be available in different situations to permit drivers

enough time and distance to control their vehicles so that the chances of accident are minimized.

The stopping sight distance is the clear distance ahead needed by a driver to bring his vehicle to

a stop before collision with a stationary object in his path and is calculated as the sum of braking

distance required at a particular speed plus the distance travelled by the vehicle during perception

and brake reaction time (lag distance).Total reaction time of drivers depends on a variety of factors

and a value of 2.5 seconds and coefficient of longitudinal friction varying from 0.40 for 20 km/hr to

0.35 for 100 km/hr. Stopping Sight Distance (Ds) shall be:


EEAP 22

Where,

Ds = Stopping Sight Distance, m

V = Speed, km/hr

t= Perception and Brake Reaction Time, seconds (2.5 seconds)

f = Coefficient of Longitudinal Friction (Varies as speed varies)

The Safe Stopping Site Distance is provided in Table below.

Table 6.3 : Safe Stopping Site Distance

6.6 Vertical Alignment

All vertical curves are suggested simple parabolas according to the Nepal Road standards. Vertical

curves are unavoidable due to drainage problems and topography of project area. This road project

is located in hilly terrain so vertical curves are designed according to the Nepal Road standards.

6.7 Gradient

The selection of ruling gradient depends on several factors such as type of terrain, length of the

grade, speed, pulling power of vehicles and presence of horizontal curves.

Recommended gradient for different terrain conditions are given in Table below:

S.No Design Standard

District Road (Core

Network)

Hill Terai

1 Ruling gradient (%) 7 5

2 Limiting gradient (%) 10 6

3 Exceptional gradient (%) 12 7

4 Limitation of maximum gradient length (m) above average gradient of

7%

300 -

5 Maximum recovery gradient (%) to be applied after gradient in excess

of 7% for a minimum recovery length of 150 m

4 -

6 Maximum gradient at bridge approach (%) 6 5*

7 Minimum gradient on hill roads (for better drainage) (%) 0.5 (max

1%)

-

However, in case of existing roads it is very difficult to maintain the longitudinal gradient within the

design limit throughout because of several factors. Among them following are some examples:


EEAP 23

There can be unnecessarily heavy box cutting for very long stretch if we don't escape from keeping

the design grade for short stretch in some sections. This means adopting more gradient than

design in some section will save heavycut/ fill for long stretch.

Changing the existing alignment may not prove practical every time for the improvement of

gradient. Hence, keeping high gradient for short stretch may resolve the issue of resettlement and

other social dispute that may result from realignment

Most of the existing roads are found non engineered road in terms of gradient. Hence, some

section need steeper gradient, also because to maintain the relief gradient in hair-pin-bend and

other stretches.

It is not wise to destroy or ruin stable and normal road sections in the cost of improving problematic

part without logical justification.

The main problems that consultant faced during survey and design of road is to maintain the design

gradient in existing road.

6.8 Vertical Curve

Vertical curves are introduced for smooth transition at grade changes. Both summit curve and

valley curve should be designed as parabolas. The length of vertical curves is controlled by sight

distance requirements, but curves with greater lengths area esthetically better.

6.8.1 Summit Curves

The length of summit curves is governed by the choice of sight distance. The length is calculated

on the basis of the following formulae

N = deviation angle, i.e the algebraic difference between the two grade

L = Length of parabolic vertical curve (rn)

S = stopping sight distance (rn)

The above formula has been derived based on the following assumption

Height of driver's eye (H) = 1.2 m (above the pavement surface)

Height of subject above the pavement surface = 0.15 m

6.8.2 Valley Curves

The length of valley curves should be such that for night travel, the headlight beam distance is

equal to the stopping sight distance. The length of curve may be calculated as follows:


EEAP 24

Where,

N = deviation angle, i.e the algebraic difference between the two grade

L = Length of parabolic vertical curve (m)

S = stopping sight distance (m)

The above formula has been derived based on following assumption

Head light height = 0.75 m

The beam angle = 10

6.9 Road Cross- Section

Following road width and other cross-sectional features have been adopted in design of RRRSDP-

2 roads.

Figure 6.1: Single Lane Road with drain in Hill area of District Road – Core Network


EEAP 25

Carriage way width in passing bays = 5.5 m

Roadway width in passing bays = 7 m

6.9.1 Cross Section Design

The cross section design was carried out taking plan and profile under consideration. For

embankment areas, the side slopes of 1.5 H: 1 V are adopted and side slopes in cutting varies

based on soil classification.

6.9.2 Shoulder Width

According to the DoLIDAR Standard the Shoulder Width is 0.75m either side adopted.

6.9.3 Carriageway Width

According to the NRRS this road adopted carriageway width 3.75m.

6.9.4 Formation Width

Roadway width of 5.25 m which includes carriageway and its shoulder width and formation width

of 6.25m including drain has been proposed.

6.9.5 Right of Way

Total right of way for this road section is 20 m (10 m either side of the road).

6.9.6 Camber

Recommended camber cross slope on straight road sections is given in Table below.

Unpaved shoulders on paved carriageway should be at least 0.5 per cent steeper than the cross

fall of the carriageway. However, 1 per cent more slope than the carriageway is desirable.

6.9.7 Pass Bay

The increased width at passing zones should allow two trucks (2 axles) to pass. The width of

carriage way should be 5.5 m and length about 12 m along the outside edge and 30 m along

inside. This means that passing zones and lay bys should be tapered gradually towards the

carriageway so that vehicles can leave or join the traffic stream safely. At passing places, vehicles

would be expected to stop or slow to a very low speed.

Passing is placed at every 300 m for Hill and 500 m for Terai. The location of passing place

depends on the sight distance and should be provided at or near blind and sharp summit curves;

where the likelihood of vehicles meeting between passing places is high and where reversing

would be difficult. In general passing places should be constructed at the most economic location


EEAP 26

as determined by the terrain and ground condition, such as at transitions from cut to fill, rather than

at precise intervals.

6.9.8 Carriageway width at culvert/ bridge

The recommended carriageway width at culverts and for Single lane is 4.25 m and Intermediate

lane 6m. Width is measured from between parapet walls or kerbs and additional width for footpath

can be considered as per site requirement and volume of pedestrian flow.

6.9.9 Level of road embankment above hfl

In flat terrain, the road embankment should be high enough so that the level of subgrade is above

the highest flood level (HFL). HFL at site can be found from inspecting the site and local enquiry.

Minimum recommended level of sub grades is given below for district road (core network) 1 m

desirable but minimum is 0.5 m for village road 0.5 m (minimum)

6.9.10 Lateral Clearance

Lateral clearance between roadside objects and the edge of the shoulder should normally be as

given below:

Hill road - normally 1.0 m but may be reduced to minimum O.5m in steep and difficult areas and

where the cost of providing the full clearance is high.

6.9.11 Vertical Clearance

A vertical clearance of Sm should be ensured over the full width of roadway at all underpasses,

and similarly at overhanging cliffs. The vertical clearance should be measured with reference to

the highest point of the carriageway i.e the crown or super elevated edge of the carriageway.

However, in the case of overhead wires, poles etc. clearance shall be at least 7.0 m above the

road surface.

6.9.12 Cut / Fill Batter Slopes

Cut/fill slope designs are normally based on geo-technical parameters, such as soil and rock

properties, terrain slope, water tables and height of cut slope.

The cut slope gradient should be between 1:0.3 (V: H) and 1:1.5 depending on subsurface

conditions and other characteristics. Attention shall be paid to the geological condition of the slope

prior to cutting of the slope.

As a rule, cutting and removal of soil mass should be performed from upper to lower portion to

maintain the slope stability. Cutting work should be carried out during dry season. The final cut

slopes should be treated with adequate drainages, slope protection works and/or bioengineering

works to increase stability against effects of rainfall and infiltration of water.


EEAP 27

CHAPTER VII – ENVIRONMENTAL MITIGATION MEASURES

As per Environmental Protection Act 2053 and Environmental Protection Regulation 2054 Initial

Environment Examination (IEE) is mandatory for all kind of District and Rural roads and hence IEE

are conducted for each sub-project to investigate the possible environmental impacts during and

after implementation of project in socio-economic & cultural aspects, biological and physical

sectors of proposed road influence zone.

Detailed Cost estimate of environment management plan to mitigate and safeguard the adverse

impacts will be prepared separately and be incorporated as civil works item in Bill of Quantity of

bidding document. In general the provision of bioengineering is made in this estimate. In order to

discourage uncontrolled cut and throw of spoil mass a separate item of transportation of excess

mass from roadwork has been introduced in detailed estimate for mass management. EMP will

cover rehabilitation of public infrastructures and will address to slope stabilization work. However

mitigation of adverse environmental impact should be began right from feasibility, alignment study

and design phase. Following are some attempts that the consultant has tried to address to

minimize environmental impact during its planning phase.

7.1 Consideration Made in Alignment Selection, Survey and Design Phase

Following attempts and considerations have been made during detailed engineering as part of

environmental mitigation measures in planning phase:

Road alignment selection that avoids landslide-prone and geological unstable areas,

sensitive ecosystems, and important cultural and religious sites;

Road alignment selection that avoids large scale cutting and filling and that is based on

mass balancing;

Proper design of cut slopes to minimize possibility of destabilization;

Provision of suitable drainage facilities utilizing discharge to natural drainage channels;

7.2 Drainage Outlet Protection Works

Construction of side drain and culverts and other drainage work (for quick drain out the surface

run-off) alone is not always enough for water management. The possible erosion and gulley

formation inclusive of damage of cultivated land and other private property is common at outlet of

culverts. That is why there is always dispute with local farmers regarding the location of cross-

drain during construction works. Keeping view of these, different types of outlet protection works

have been designed and proposed in the cost estimate as one of the mitigation matter of adverse

environmental impact.

7.3 Selection of Slope Protection Work

In general, following points are considered while planning a slope protection work:

Use of bio-engineering on all exposed cut and fill slopes, weak and fragile zone and on completed

spoil tips to minimize subsequent erosion. Provisional sum have been introduced in the estimate

and will be break downed and finalized with detailing during construction works;

Water management structures as an essential factor for quick and effective drainage of surface

run-off have been introduced. Side drain and other cross drainage structures have been selected

and determined keeping view of nature and characteristics of gullies, stream and spring.


EEAP 28

Restrain measures such as retaining wall and structures like gabion wall and stone masonry have

been provided to retain the fill mass and for prevention of toe failure.

7.4 List of Some Environment Protection Works

As per findings of field investigations following environmental protection measures have been

proposed in design and estimate of roadwork

S.N. ENVIRONMENT PROTECTION MEASURES

1 Provision of spoil mass transportation up to nearby tipping sites

2 Shifting of Electric poles, water supply pipelines etc from roadway to safe sites

3 Bioengineering works along with small slope protection civil structures

4 Rehabilitation and reconstruction of irrigation canals

5 Inlet and outlet protection works of cross drainages, culverts to mitigate the

damage to cultivated land, private property etc

6 Provision of breast walls in potential and existing landslide area

7 Proper drainage management to protect the road and roadside slope from adverse

effect of accumulated water


EEAP 29

CHAPTER VIII – DETAILED ENGINEERING DESIGN

8.1 Design Method

Design of the road was carried out by SW_ROAD 2006 and SW_DTM 2006 computer software

developed by SOFTWEL (P) Ltd, Nepal. Design was carried out using strip survey method so that

alignment could be optimized as per requirement. The design works are based on the Digital

Terrain Model created from the 3D points captured through the detailed survey.

Centerline was generated using the design environment and accordingly the profile and cross-

sections were generated. Through an interactive design environment, the centerline (plan and

profile) is optimized by adjusting the cross-sections.

8.2 Review & Redesign

Attempts have been made to minimize the cut/fill volume of earthwork and unnecessary stuff of

structures. Once the computer designed plan and profiles printed, the profiles were thoroughly

reviewed and redesigned wherever necessary to optimize the design and to keep it in right track

within the norms and standard. Necessary adjustment has been made in difficult areas where to

follow the design standard is likely not justifiable and impractical.

8.3 Design & Drawings

The detailed engineering design and drawings is based on the data collected during detailed

engineering survey.

The detailed designs has been done or prepared by the Consultant following the DoLIDAR’s Nepal

Rural Road Design Standards 2055 (with 2nd Revision of September 2012) and detailed and

standard drawings are prepared as mentioned in the DoLIDAR Technical Guidelines.

The designs and drawings consist of the design profile, design cross-section, plan and other

standard/typical drawings.

8.4 Horizontal Curve Design

The horizontal curve design table along with different features and parameters of horizontal

alignment has been presented in annex and in drawings.

8.5 Design of Structures and other geometric Features

The list of retaining and cross drainage structures extracted from detailed design output is

presented in annexes. Similarly, the standard drawing represents the adopted design standard of

road cross-sections. The list of passing bays is also attached in annex.

8.6 Pavement Proposed

This Khopasi - Dhungkharka - Chyamrangbeshi - Milche - Borang Road is designed to gravel /

cobble standard. Sub-base material with following properties of river gravel or crushed material

shall be laid and compacted to desired field density.

8.6.1 Plasticity Index = <6

CBR of material after 4 days soaking = > 30% at 95% MDD.


EEAP 30

Grading Envelope for Gravel:

Sieve size (mm) % 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 – 37

0.075 4 - 15

Traffic growth rate (r) = 5% (assumed for rural road)

The accuracy of design will also depend very largely on the accuracy of traffic prediction over the

chosen life of 15 years. According to IRC and Road Note 29 it suggests to take a normal traffic

growth rate of 4%, but in Nepal from its past trend a traffic growth rate of 5% for rural roads is

appropriate though ‘Flexible Pavement Design Manual - 2070’ by DoR suggests to use a traffic

growth of 7% for strategic (SRN) roads. And the type of pavement selection will depend on not

only projected traffic volume but also economic considerations as well. Design period (n) = 15 yrs

The projected traffic volume of 15 years includes the construction years of 2 to 3 years (the road

being upgraded traffic growth will continue to grow during construction as well and the road cannot

be fully closed during construction. LDF (Load Distribution Factor) = 0.75 (for 2 lane road)

According to latest traffic count done by RRRSDP-2 on Khopasi - Dhunkharkha – Chyamrangbesi

Road the recorded traffic volume per day is 70 PCU only. Equivalency factor used for converting

the commercial vehicles (bus, trucks, tractors) to PCU is 3 for Bus up to 40 passengers & Minibus

and similarly for Truck up to 10 tonnes gross weight is also 3. We can assume 17 ~ 20% of PCU

as number of buses and minibuses and 8~10% of PCU as trucks plying on the road. Because

the loads imposed by cars and light vehicles do not contribute significantly to the structural

damage caused to road pavements by traffic. For the purpose of structural design, therefore,

only the numbers of commercial vehicles having unladen weight exceeding 1500 kg and their axle

loadings are considered.

Now, assume number of buses (8 ton) = 14, say (@ 20% of 70 PCU)

Assume number of trucks (10 ton) = 7, say (@ 10 % of 70 PCU)

Cumulative Equivalent Standard Axles (ESA) at base year = (A*VDF) = (Number of traffic x

vehicle damage factor, which taken as 0.91 for bus and 2.5 for truck as per Overseas Road Note

(ORN) 31. NB: It can be calculated using, VDF = (Axle load (kg)/8160)^4.5)A*VDF = 14x0.91+7x2.5

= 12.74 + 17.5 = 30.24 ESA/day So, the cumulative number of 8160 kg (82KN) equivalent standard axle over design life is

calculated as follows:

Numerically, Ns = [365 * [(1+r)^n-1] *(A*VDF)*LDF]/ r

VDF = Vehicle damage factor = multiplier to convert the number of commercial vehicles of


EEAP 31

different axle loads & configuration to the number of standard axles load repetitions. It is defined

as the equivalence factor of standard axles per commercial vehicle.

Ns = [{365*{(1+0.05)^15-1}*(30.24)*0.75}]/0.05 = [{365*1.079*30.24*0.75}]/0.05 = 327805.4ESA =0.327,805 Million Standard Axle (msa).

However, with the upgrading of roads the additional traffic may be attracted or diverted through this road. In absence of traffic count data, it is proposed to increase the above value by 75%. This makes the design traffic value as 1.75*0.327 = 0.577 msa. See Map below to have an idea of traffic diversion or attraction possibility.

Hence as per ORN 31, this traffic falls into Class T2 (0.3 msa to 0.7 msa).

Therefore, referring to ORN 31 again the pavement thicknesses for granular road-base materials

with this traffic class T2 and subgrade strength classes based on the range of CBR values as

shown below in the Table in different sections figure out to as follows:

Therefore, referring to ORN 31 again the pavement thicknesses for granular road-base materials

with this traffic class T2 and subgrade strength classes based on the range of CBR values as

shown below in the Table in different sections figure out to as follows:


32

Table 8.1 : Summary of the Dynamic Cone Penetration Test (DCP) Test Results Showing CBR Values in Different Sections of Khopasi - Dhunkharkha – Chyamrangbesi Road under RRRSDP-2

S.N. Chainage Depth of Layers in mm CBR Value in

%

Subgrade Strength Classes for Design asper

ORN31

Granular Base Course(BC)and Sub-base Course

(SC)Thicknesses in mm with Surface Dressing (SD)

Refined** & Recommended

Thicknesses of gravel layer in mm

15 14+000 0-397 34.3 S5

SC =150

150 397-900 13.6

16 15+000 0-320 44.5

S5 SC =150

150 320-400 22.5

400-430 114.7

430-630 42.7

17 16+000 0-210 24.4

S5 SC =150

150 210-250 49.7

250-655 38.1

18 17+000 0-345 15.3

S5 SC =150

150 345-617 24.4

617-1000 4.6

19 18+000 0-280 36.1

S5 SC =150

150

280-300 69.8

300-535 18.3

535-755 29.2

240-1000 7.4

Note: The road is designed for gravel road only because of low traffic volume and minimum thickness of gravel road is 150 mm as per IRC standard


33

CHAPTER IX – COST ESTIMATE

9.1 Summary

The total estimated construction cost for upgrading of Khopasi - Dhungkharka - Chyamrangbeshi

- Milche - Borangroad is summarized in the table below, which does not, include compensation

for building and land.

S. N. Road Name Length

Km

Cost Estimate

NRs Cost per km

1

Khopasi - Dhungkharka -

Chyamrangbeshi - Milche -

BorangRoad

4.537

NRs 106,880,708.02

Including VAT and

Contingencies

NRs 23,557,572.85

Including VAT and

Contingencies

The details of the cost estimation are provided in Volume II of this report

9.2 Quantity Estimate

Quantity estimates are based on the cross-section designs. The quantity of different items of work

like earthwork excavation, filling etc. is calculated by using the Design software and on the basis

of standard engineering formulae. However, some minor adjustment might be needed which

would be verified during the construction phase.

9.3 Rate Analysis

During the calculation of unit rates, three major components labor, material and equipment were

considered. Unit quantities for all these three components were taken from the DoLIDAR and DoR

Work Norms and Specifications. Similarly, the cost of labor and construction materials, are based

on the district rates of DDC for the fiscal year 073/74. The rate of labor, material and equipment

is then increased by adding VAT of 13%.

9.4 Cost Estimate

The detailed cost estimate has been prepared using the calculated quantities and unit

rates, derived from standard applicable District Rates and DoLIDAR & DoR Work

Norms.

Contract packaging will be suitably done for all subprojects, and respective bidding

documents will be prepared following the DoLIDAR practices and frameworks.

9.5 Conclusion

Due to adaptation of higher standard road width section than previous design standard (from 5.00

m to 6.25 m) it is rational to increase the volume of earthwork and retaining structures which along

with raised daily wages obviously increased the per kilometer cost of road. Similarly, due to

presence of high and steep gradients and hair-pin-bends the quantity of structures increased while

trying to bring it within permissible design standard and thus resulting in per kilometer cost


34

CHAPTER X – CONCLUSION & RECOMENDATION

The EEAP has proposed to upgrade this of Khopasi - Dhungkharka - Chyamrangbeshi - Milche –

Borang Road to all weather gravel / cobble standard. Other intervention includes widening of

narrow track and improvement of longitudinal gradient to bring it within geometric standard of

District Road Core Network. Furthermore provision of passing bays, construction of proper

drainage system including lined drain, box & pipe culverts and causeways have also been

proposed following DoLIDAR guidelines and geometric standard of Nepal Rural Road Standards.

Upgrading and improvement of this district road will improve access and mobility of settlements

of Khopasi, Chalalganeshthan, Dhungkharka and Chyamrangbeshi VDCs to market, education

and service center, health and other economic activities. The road will play a vital role to change

the traditional subsistence agriculture pattern to commercial farming with increase in cash crops,

horticulture and dairy & poultry farming in the zone of influence area by providing access to dense

populated market centers of district and also up to metropolitan city Kathmandu.

Upgrading of the road will help the people of the area to receive better education and quick access

to medical facilities. Government’s other services will also be delivered better. It is expected to

reduce the travel time further after the implementation of this project which will inspire people to

use the saved time in income generating activities.

The total cost of the project is estimated NRs 106,880,708.02 for 4.537 Km of length with VAT and contingency. The unit cost per Km is estimated at NRs 23, 557, 572.85 including VAT and Contingency.

CONCLUSION

Improvement and upgrading of this road to all weather standard will enhance the increased

access to markets and social services; provide opportunity to use saved travel time for productive

income generating works; development horticulture, cash crop, diary production and other agro-

based industry etc, which eventually pave the way to achieve the program goal of reduce the

poverty through creating employment generation.

ANNEXES

LIST OF BENCHMARKS

LIST OF PASSING BAYS

DCP TEST DATA

earthquake emergency assistance project kupondole, lalitpur · 2017-08-30 · government of nepal...

Documents