Rural Road Engineering in Developing Countries

Cover
Half Title
Title Page
Copyright Page
Table of Contents
Foreword
Authors
Abbreviations and Acronyms
Introduction
1 Roads, Development and Related Policy
Introduction
Roads and Rural Development
Key Issues
The Sustainable Development Goals
The Rural Access Index
Rural Road Policy
The Role of Policy
Policy Implementation
Strategic Planning
References
2 The Whole-Life Road Cycle
Introduction
Structure of the Whole-Life Road Cycle
Life-Cycle Stage Detail
Planning
Feasibility
Final Engineering Design (FED)
Construction
Maintenance
Rehabilitation or Upgrade
References
3 Road Classification and Function
Introduction
Appropriate Classification
Road Function
The Role of Classification, Standards and Specifications
Rural Road Traffic
Traffic Types
Rural Road Traffic Assessment
Rural Road Safety
Road Safety in LMICs
Improving Rural Road Safety
Road Design and Rural Road Safety
References
4 Roads and the Green Environment
Introduction
Road Environment Impacts
Water Resources
Soil Degradation
Surface Flow and Flooding
Health and Safety
Impacts on Ecosystems and Biodiversity
Deforestation
Socio-Economic Impacts
Cultural Heritage
Environmental Impact Assessments
Background
Initial Environmental Examination
Screening
Scoping
Baseline Surveys
Assessment Methods and Techniques
Environment Impact Management
The Environmental Plan
Environmental Monitoring
Mitigation of Impacts
Some General Issues
Planning Issues
Construction
Maintenance
Sustainable and Environmentally Optimised Design Options
References
5 Appraisal of Low Volume Rural Road Initiatives
Introduction
Principles
An Appraisal Framework for LVRRs
Key Issues
Political and Policy Support
Economic Viability
Institutionally Possible
Socially Acceptable
Technically Appropriate
Financially Feasible
Environmentally Sustainable
Economic Appraisal of Major Roads
The Economic Evaluation of low Volume Rural Roads
Background Characteristics
Methodologies and Tools
Highway Development and Management Model, Version 4 (HDM4)
The Roads Economic Decision Model (RED)
Consumer Surplus Methods
Producer Surplus Methods
Cost-Effectiveness Analysis
Road Maintenance
References
6 The Rural Road Environment
Introduction
The Engineering Environment Factors
Climate
Hydrology
Terrain
Construction Material Properties
Subgrade and Foundations
Traffic
The Construction Regime
Maintenance
The Operational Environment Factors
Policies
Classification
Road Design Standards
Technical Specifications
Funding Arrangements
The Contracting Regime
The Green Environment
The Socio-Economic Environment
Principle
Local Employment
Development of Local Enterprise
Complementary Interventions
Road Inventory data Collection and the Design Process
References
7 Site Investigation
Introduction
Investigation Framework
Engineering Investigations
Non-Engineering Investigations
Investigation Aims
Ground Investigations
Desk-Study
Walkover Surveys and Geotechnical Mapping
Traffic Surveys
Pitting, Boring and Drilling
Geophysical Methods
Laboratory Testing
Aims
Testing Programmes
Test Identification and Selection
The Laboratory Environment
Investigation Implementation
Level of Investigations
Main Investigation Information
Climate Resilience Investigations
Structures Investigations
Tropically Weathered Soil–Rock Materials and Masses
The Nature of Tropically Weathered Soil–Rock Profiles
Behaviour
Investigating TWIMs
Data Management
Managing Uncertainty for the RDM
Laboratory data Management
References
8 Natural Construction Materials
Introduction
The Geological Context
Geological Background
Material Properties
Material Requirements
Common Fill
Imported Subgrade or Improved Fill
Gravel Wearing Course
Sub-Base and Base Aggregate
Bituminous Surfacing Aggregate
Surfacing Block or Paving Stone
Aggregates for Structural Concrete
Filter/Drainage Material
Gabion Fill
Embankment Rock Fill
Riprap
Masonry Stone
Materials Management
Extraction and Processing of Materials
Use of Locally Available Materials
Marginal Materials
Appropriate Use
Assessing Marginal Materials
Material Improvement
General
Mechanical Stabilisation
Chemical Stabilisation Principles
Cement Stabilisation
Lime Stabilisation
Bitumen Stabilisation
References
9 Geometric Design
Introduction
Factors Influencing Geometric Design
Key Issues
Cost
Terrain
Pavement Type
Traffic Volume and Composition
Safety
Key Geometric Design Elements
Design Speed
Road Width
Cross-Fall
Adverse Cross-Fall and Superelevation
Gradient
Stopping Sight Distance
Road Curvature
Summary
Departures from Standards
Examples of Geometric Standards
References
10 Earthworks
Introduction
Excavation
Principles
Excavation
Embankment Design
General Approach
Soft Soils Foundations
Expansive Soils
Compaction
Cut Formation
General Approach
Cut to Fill
Tropically Weathered Soils and Earthworks
Slope Protection and Stabilisation
Earthwork and Natural Roadside Slope Instability
General Approaches to Slope Stabilisation and Protection
Retaining and Revetment Walls
Slope Drainage
Bio-Engineering
General
Key Factors
Preparation
Recommended Techniques
References
11 Hydrology and Drainage
Introduction
Hydrological data
Rainfall
Rainfall Analysis
Data Challenges
Information Surveys
Flood Discharge Estimation
Direct Flow data
Climate Change and Hydrology
Key Issues
General data Sources
Changing data and Standards
Hydrology and Risk
References
12 Cross-Drainage Small Structures
Introduction to Cross-Drainage
Cross-Drainage Types
Simple Culverts
Fords and Drifts
Potential Benefits of Low-Water Crossings
Small Bridges
Key Design Cross-Drainage Issues
Selection
Basic Design Framework
Appropriate Design Life of the Structure
Physical Siting
Traffic
The Hydrology and Flood Regime at the Structure Location
Some Special Design Considerations
Local Resources
Climate Resilience
Safety
Maintenance Regime
References
13 Low Volume Rural Road Pavement Design Principles
Introduction
Aims
Pavement Components
Background
Key Pavement Design Issues
Rural Road Pavements Options
Fitness for Purpose
Whole Life Cycle and Costs
Environmentally Optimised Design (EOD)
Appropriate Use of Locally Available Materials
Equilibrium Moisture Content
Pavement Design Framework
A Phased Approach
Road Environment Compatibility
Phase I Pavement Option Selection
Pavement Design Phase
General Approach to Phase II
Rural Road Pavement Design Methods
Pavement Design Catalogues and Charts
The Role of Subgrade and its Assessment
Pavement Drainage
General Requirement
External Drainage
Longitudinal Drainage
Internal and Subsurface Drainage
References
14 Bituminous Pavements
Introduction
Surfacing Options
Bitumen Options
Bitumen Use
Sand Seal
Slurry Seal
Chip Seal
Otta Seal
Cape Seal
Penetration Macadam
Cold Pre-Mix Asphalt
Hot Mix Bitumen Macadam
Selecting of Seal Options
Factors Impacting Bituminous Seal Performance
Key Issues in the Design of Bituminous Surfacing
Structural Design of low Volume Bituminous Pavements
General Approach
Design Charts for Bituminous-Sealed Options
References
15 Non-Bituminous and Concrete Pavement Options
Introduction
Background
Approaches to Non-Bituminous Detailed Pavement Design
Earth and Gravel Roads
Engineered Natural Surface (ENS)
Natural Gravel Surfaced Pavements
Stone Roads
Waterbound/Drybound Macadam
Hand-Packed Stone
Stone Setts or Cobble Stones
Fired Clay Brick
Concrete Pavements
General
Concrete Slabs
Concrete Block Paving
Geocells
Option Comparison
References
16 Spot Improvement
Introduction
The Spot Improvement Concept
Environmentally Optimised Design
Spot Improvement Principles
Application
Programming
Prioritisation
Links to Climate Resilience Strengthening
Implementation
References
17 Climate Resilience
Introduction
Climate Change
Background
Definitions
Climate and Rural Roads
Climate Resilience Strategy
Climate Resilience Principles
Climate Resilience Performance Levels
The Importance of Policy and Planning
Climate Resilience Application
Climate Resilience in the Road Life Cycle
Climate Resilience Application
Climate Resilience Adaptation Options
Adaptation data
Engineering Options
Climate Resilience Non-Engineering Options
References
18 Procurement and Documentation
Introduction
Procurement Strategy
Contracting Options
In-House or Agency
Conventional Contracts
Design and Build
Concessions
Performance-Based Contracting
Supervision Contracts
Appropriate Documentation
Final Engineering Design
Standard Documents
Technical Specifications
The Bidding Process
Prequalification
Bid Submission
Evaluation and Appointment
References
19 Construction Supervision and Quality Management
Introduction
Quality Management
The Framework
Quality Control and the Quality Plan
Quality Assurance
Supervision Activities
Aims and Responsibilities
Key Supervision Activities
Laboratory and in Situ Testing
Approving Material Use
The Observational Method
Technical Audits
Objective
Procedures for Technical Audits
As-Built Survey
References
20 Road Maintenance Strategy
Introduction
Rural Road Maintenance Management
Aims
Challenges
Road Maintenance Policy
Policy as Driver of Maintenance
Policy Framework
Associated Strategy
The Maintenance Environment
Key Factors
Climate Change and Maintenance
Flexibility of Response
Principal Actions
Maintenance Cycle and Budgeting Framework
Maintenance Management System: Basic Elements
Information Management
Condition data Analysis
Low-Cost Roughness Measurement
High-Tech Approaches to Rural Road Condition data Collection
Maintenance Management Performance
The Road Preservation Pyramid
Monitoring and Audit
References
21 Road Maintenance Procedures
Introduction
Key Rural Road Maintenance Issues
Maintenance Aims
Classification
Sequence of Key Actions
Specific Maintenance Actions
Carriageway and Roadside
Timing
Structures
Procurement and Implementation
Contracting Options
Force Account
Private Sector: Conventional Quantity-Based Contracts
Performance-Based Contracts
Contracting Entities
Implementation Challenges
Training Requirements
Reducing the Maintenance Burden
Climate Change Adaptation
References
22 Appropriate Technology
Introduction
Key Definitions
Local Resources
Labour-Based Operations
Intermediate Equipment
Heavy Equipment Based or Capital Intensive
Roadworks Technology Background
Development of Labour-Based Approaches
Choosing an Appropriate Technology
Technology Choice Review
Key Issues
Heavy Equipment Use for Unpaved Rural Roads
Labour-Based Road works Technology
Intermediate Technology Equipment
Case Studies in Appropriate Technology for Roadworks
Kenya
Zimbabwe
Vietnam: Intermediate Technology in Rural Road Construction
Creating the Enabling Environment for Technology Change
Key Issues
Stakeholder Roles
Summary
References
Appendix A: Standard Data Collection Sheets
Glossary of Technical Terms
Index