Contenido Microtunneling and horizontal drilling. Recommendations

This book includes recommendations prepared by members of the French Society for Trenchless Technology (FSTT), based on their recent national multi-year project. Comprehensive guidelines, techniques and theories in the areas of both microtunneling and horizontal drilling are given, encompassing the fields of application for each method, what investigations should be undertaken, which machines and equipment should be used, how the work should be managed and potential problems that may arise.
The recommendations, the analytical methods used and their verification with laboratory and field data should not only improve the rate of success of trenchless projects, but will also be of great value to engineers in other countries, who can compare the results with their own findings and assess the international state of the art.

Table of Contents:

Preface
André COLSON

Introduction
Michel MERMET

PART I. MICROTUNNELING

Chapter 1. Introduction to Guidelines: Subject and Fields of Application

1.1. General introduction of “trenchless technology”
1.2. History and characteristics of microtunneling methods
1.3. Purpose of the guidelines

Chapter 2. Techniques and Theory of Operation for the Installation of Pipes by Microtunneling

2.1. General information
2.2. Different functions of a boring machine
2.2.1. Mechanized excavation of the soil
2.2.1.1. Blasting the soil
2.2.1.2. Confinement of the face
2.2.2. Discharge of excavated earth (or mucking)
2.2.2.1. Hydraulic mucking
2.2.2.2. Mucking with a screw conveyor
2.2.2.3. Pneumatic mucking
2.2.3. Guidance and trajectory correction
2.2.4. Installation of pipelines by jacking
2.3. Various types of pipes
2.3.1. Materials used
2.3.2. Joints between pipes
2.3.3. Resistance capacity of pipes

Chapter 3. Summary of Parameters Affecting Work at the Site

3.1. Summary of parameters affecting the microtunneling.
3.1.1. Rate of penetration
3.1.1.1. Duration for pipe jacking only
3.1.1.2. Total duration for the installation of a pipe in the ground
3.1.2. Alignment deviations
3.1.2.1. Human factors
3.1.2.2. Technological factors
3.1.2.3. Factors linked to the soil
3.1.3. Frictional forces
3.1.3.1. Principle of analysis for experimental data
3.1.3.2. Effect of the overcut
3.1.3.3. Impact of the downtimes
3.1.3.4. Impact of lubrication
3.1.3.5. Impact of misalignment
3.1.3.6. Impact of granulometry
3.1.4. Stresses at the head
3.1.4.1. Presentation of general results
3.1.4.2. Influence of blasting and mucking
3.1.4.3. Influence of trajectory deviations
3.2. Description of the main hitches that can occur when constructing a microtunneling site
3.2.1. Blocking of the machine
3.2.1.1. Various boulders and obstacles
3.2.1.2. Excessive friction
3.2.1.3. Abrasiveness of the soil
3.2.1.4. Sticking of clay
3.2.2. Damaged pipes
3.2.3. Surface disturbances
3.2.3.1. Settlement caused by the annular space
3.2.3.2. Instability of the face, poor balancing of the pressure at the face
3.2.4. Excessive roll

Chapter 4. Guidelines for Investigations

4.1. General approach of the investigations
4.1.1. General objectives
4.1.2. Progress of the investigations
4.1.3. Cost of investigations
4.2. Data to be acquired
4.2.1. Geological configuration of the site
4.2.2. Hydrogeological conditions
4.2.3. Geotechnical characteristics of the ground
4.2.4. Cavities and artificial obstacles
4.2.5. Environmental conditions
4.3. Methodology and means of investigation
4.3.1. Documentary survey
4.3.2. Geophysical investigations
4.3.2.1. Objectives
4.3.2.2. Usefulness of different methods
4.3.2.3. General guidelines
4.3.3. In situ boreholes and geotechnical tests
4.3.3.1. Objectives of boreholes
4.3.3.2. Layout of boreholes
4.3.3.3. Types of in situ tests
4.3.3.4. Guidelines on the choice of boreholes and tests
4.3.4. Geotechnical tests at the laboratory
4.4. Contents of the geological record

Chapter 5. Guidelines for the Choice of Machines and Attachments

5.1. General information
5.2. The choice of machines according to their mucking process
5.3. Choice of attachments
5.3.1. The heads: opening, cutting tools
5.3.2. The overcut
5.3.3. The crusher
5.3.4. Bore fluids

Chapter 6. Guidelines for Project Design, Dimensions of Pipes and the Pipe Jacking System

6.1. Design of shafts
6.2. Calculation of pipe jacking stresses
6.2.1. Definition of friction between the soil and the pipes
6.2.1.1. General definition
6.2.1.2. Specific friction values
6.2.2. Experimental results relating to unit friction
6.2.2.1. Results of the French National Research Project “Microtunnels”
6.2.2.2. Results of other studies
6.2.3. Calculation methodology for frictional forces
6.2.3.1. Verification of the stability of the excavation
6.2.3.2. Ground convergence effect
6.2.3.3. Calculation of frictional forces for unstable excavation in granular soil
6.2.3.4. Calculation of frictional forces for unstable excavation in cohesive soil
6.2.3.5. Calculation of frictional forces for a stable excavation
6.2.4. Comparison of various approaches with experimental values
6.2.4.1. Calculations-measurements comparison: granular soil without lubrication
6.2.4.2. Calculations-measurements comparison: granular soil with lubrication
6.2.4.3. Calculations-measurements comparison: cohesive soil without lubrication
6.2.4.4. Calculations-measurements comparison: cohesive soil with lubrication
6.2.5. Guidelines for the calculation of pipe jacking stresses
6.2.5.1. Dynamic friction: non-cohesive soil
6.2.5.2. Dynamic friction: cohesive soil
6.2.5.3. Additional friction caused by stoppage in jacking
6.2.5.4. Stress on the cutter head
6.2.5.5. Estimate of the maximum pipe jacking stress
6.3. Calculation of the maximum acceptable thrust by the pipes during jacking
6.3.1. Calculation principle
6.3.2. Permissible stress in the pipes
6.4. Calculation of the cross-section of pipes
6.4.1. Various verifications of the calculation of the size of pipes
6.4.2. General calculation principles: basic Terzaghi model
6.4.3. Vertical loads to the soil alone
6.4.3.1. The experimental Terzaghi model
6.4.3.2. The ATV A161 metho

6.4.3.3. Leonards’ model
6.4.3.4. Guidelines for the calculation of vertical loads
6.4.4. Horizontal loads of the ground
6.4.5. Surface loads
6.4.5.1. Permanent surface loads
6.4.5.2. Traffic loads
6.4.6. Water pressure: presence of groundwater
6.4.7. Permissible stress in the pipes
6.5. Bore fluids
6.5.1. General information
6.5.2. Selection criteria
6.5.3. Products used
6.5.4. Recycling and processing
6.5.5. Implementation at the site
6.5.6. Slurry treatment: technical and regulatory aspects
6.5.6.1. General considerations
6.5.6.2. Current regulations
6.5.6.3. Lines for removal of drilling residues
6.5.6.4. Prospects for reclamation

Chapter 7. Guidelines for the Site Supervision

7.1. Guidelines for guidance
7.1.1. Necessity of controlling trajectory deviations
7.1.2. Guidelines for the measurement of deviations
7.1.3. Guidelines for the monitoring of deviations
7.1.3.1. Initial adjustments and starting of jacking
7.1.3.2. Corrections during jacking
7.1.3.3. Adjustment of the overcut
7.2. Guidelines on the drilling parameters
7.2.1. Avoid instability of the face
7.2.2. Avoid excessive thrust on the head and the blocking of the cutterhead
7.2.3. Checking the roll
7.3. Guidelines on lubrication
7.4. Guidelines regarding stoppages during jacking
7.4.1. Provision for the increase in the thrust during restarting
7.4.2. Limit the increase of the thrust during restarting
7.5. Data acquisition during the project

Chapter 8. Socio-Economic and Contractual Aspects

8.1. Social and economic aspects: concept of social cost
8.1.1. Value of modern urban sites
8.1.1.1. Total cost of the work
8.1.1.2. Direct cost
8.1.1.3. Overhead cost
8.1.1.4. Social cost
8.1.2. Traditional urban sites: nuisance factors
8.1.2.1. Traffic disruption
8.1.2.2. Damage to the environment
8.1.2.3. Risk of accidents
8.1.2.4. Economic impacts
8.1.3. Reduction in nuisance by trenchless techniques
8.1.4. Methods for evaluating the social cost
8.1.4.1. Methods used in a context other than that of urban sites
8.1.4.2. Approaches as part of urban underground sites
8.1.4.3. Comparison methodology for the costs of trench and trenchless techniques
8.1.5. Other suggestions to reduce the social cost
8.1.5.1. Susceptibility maps
8.1.5.2. Financial incentives
8.1.6. Conclusions

8.2. Contractual aspects: objectives and success factors
8.2.1. Proper contractualisation of a microtunneling project
8.2.1.1. Well defined respective roles
8.2.1.2. Appropriate risk management
8.2.1.3. Knowledge of the structure and underground use
8.2.1.4. Suitable allotment and contracting
8.2.2. Establishment of appropriate tender documents and a consultation regulation
8.2.2.1. Tender documents based on a defined strategy
8.2.2.2. Specifications adapted to every item of the tender documents
8.2.2.3. A properly described project
8.2.2.4. Correctly sized and adapted products
8.2.2.5. Well defined and controlled microtunneling procedures
8.2.3. Presentation of compliant and pertinent offers by the contractor
8.2.3.1. Appropriate qualifications
8.2.3.2. Adequate and adapted references
8.2.3.3. A complete and definite technical submission

PART II. HORIZONTAL DRILLING

Chapter 9. Introduction to Guidelines: Purpose and Fields of Application

9.1. General introduction of “the trenchless technology”
9.2. History and characteristics of drilling methods
9.3. Purpose of the recommendations and fields of application

Chapter 10. Techniques and Principles of Operation for Horizontal Drilling

10.1. General information
10.2. Different stages of horizontal drilling
10.2.1. Pilot drilling
10.2.2. Reaming
10.2.3. Guidance and trajectory corrections
10.2.3.1. Walk-over systems
10.2.3.2. Downhole systems or wireline steering systems
10.2.4. Site organization
10.2.4.1. Administrative authorizations
10.2.4.2. Access, site installation
10.2.4.3. Water
10.2.4.4. Slurry transfers
10.2.4.5. Work areas
10.3. Different types of pipes or conduits
10.3.1. Thermoplastic pipelines
10.3.1.1. Polyethylene pipes
10.3.1.2. Polyvinylchloride pipes
10.3.2. Metal pipelines
10.3.2.1. Steel pipes
10.3.2.2. Pipes in ductile cast iron

Chapter 11. Summary of Parameters Affecting the Start of a Building Site

11.1. Summary of parameters affecting the execution of horizontal drilling
11.2. Parameters related to the ground

11.3. Parameters related to groundwater and soil permeability
11.4. Parameters related to obstacles
11.5. Parameters related to the nature of the pipeline to be installed
11.6. Parameters related to the drive length
11.7. Parameters related to the radius of curvature
11.8. Parameters related to the characteristics of the drilling mud
11.9. Parameters related to the characteristics of the drilling rig
11.10. Parameters related to the regularity of the profile, the piloting and the guidance
11.11. Parameters related to preliminary exploration
11.12. Parameters related to the (overall dimensions) congestion of the site
11.13. Parameters related to delays
11.14. Parameters related to weather conditions

Chapter 12. Guidelines for Explorations

12.1. General theory of explorations
12.1.1. General objectives
12.1.2. Stages of explorations
12.1.3. Cost of explorations
12.2. Data to be acquired
12.2.1. Geological configuration of the site
12.2.2. Hydrogeological conditions
12.2.3. Geotechnical characteristics of the soils
12.2.4. Pockets and artificial obstacles
12.2.5. Environmental parameters
12.3. Methodology and means of explorations
12.3.1. Documentary survey
12.3.2. Geophysical investigations
12.3.2.1. Objectives
12.3.2.2. Advantage of various methods
12.3.2.3. General recommendations
12.3.3. Drilling and in situ geotechnical tests
12.3.3.1. Test drilling objectives
12.3.3.2. Setting up investigations boreholes
12.3.3.3. Test drilling methods
12.3.3.4. Samples for laboratory tests
12.3.3.5. In situ tests
12.4. Contents of the geological-geotechnical dossier of a project

Chapter 13. Guidelines for the Choice of Drilling Rigs and Equipment

13.1. General information
13.2. Choice of drilling rigs according to their power
13.2.1. Mini drilling rigs
13.2.2. Medium drilling rigs
13.2.3. Maxi drilling rigs
13.2.4. Mega drilling rigs
13.3. Choice of drilling rigs according to their technical characteristics
13.3.1. Chassis
13.3.1.1. Base
13.3.1.2. Trailer
13.3.1.3. Track mounted chassis
13.3.1.4. Wheeled chassis
13.3.2. Transmission of forces
13.3.2.1. Chain driven
13.3.2.2. Rack and pinion
13.3.2.3. Hydraulic jacks
13.3.3. Power limits
13.4. Drilling rods
13.5. Tools
13.5.1. Wing cutters
13.5.2. Spiral compactor bells
13.5.3. Fluted reamers
13.5.4. Rock reamers
13.5.5. Barrel reamers

Chapter 14. Guidelines for a Project Design

14.1. Basic principles of a pilot pattern
14.1.1. Rack angle and exit angle
14.1.2. First and last part of the drilling
14.1.3. Radius of curvature
14.1.3.1. Radius of curvature of the pilot hole
14.1.3.2. Combined radii
14.1.4. Roofing
14.1.5. Relation between the diameters of the pipeline and the borehole
14.2. Drilling plans
14.2.1. Longitudinal profile
14.2.2. Plan view
14.2.3. Cross-sections
14.2.4. Work site installation plans
14.2.5. Catenary and launching ramp
14.3. Design notes
14.3.1. Calculation for the work stage
14.3.1.1. Pulling forces at the level of the drilling head
14.3.1.2. Tractive forces at the level of the drilling machine
14.3.1.3. Calculation methods of pulling forces
14.3.1.4. Calculation of the drilling machine dimensions
14.3.1.5. Supports
14.3.1.6. Stresses suffered by the tubes
14.3.1.7. Protection against collapse
14.3.2. Calculation of operations stage
14.4. Work planning
14.5. Drilling fluids
14.5.1. General information
14.5.2. Selection criteria
14.5.3. Products used
14.5.4. Recycling and processing
14.5.5. Implementation at the site
14.5.6. Sludge treatment: technical and regulatory aspects
14.5.6.1. General considerations
14.5.6.2. Drilling wastes eliminations solutions
14.5.6.3. Development prospects

Chapter 15. Guidelines for the Management of the Site

15.1. Guidelines on lubrication, drilling fluids
15.1.1. General information
15.1.2. Selection criteria
15.1.3. Products used
15.1.4. Implementation at the site
15.1.5. Polluted sites, environment, slurry
15.2. Recommendations on reaming
15.2.1. Reaming diameter
15.2.2. Choice of the reamer
15.2.3. Multiple bores
15.2.4. Reaming sequences
15.2.5. Reaming speed
15.2.6. Installing a protective sleeve
15.3. Guidelines on safety and protection of environment
15.3.1. Safety at the work station (at the site)
15.3.1.1. Work on inclines
15.3.1.2. Work on rotating mechanical parts and tools
15.3.1.3. Risk of slipping increased by the presence of drilling mud
15.3.1.4. Respiratory risks related to the inhalation of bentonite powder
15.3.1.5. Handling of loads during lifting (drilling rod, reamers, etc.)
15.3.1.6. Significant torsional moments during the tightening or loosening of drilling rod/tool unions
15.3.1.7. Communication between the control cab, the drilling rig and the pipeline side
15.3.1.8. Work under thoroughfares
15.3.1.9. Risks of aggressions on underground structures
15.3.2. Security of machines
15.3.3. Security of drilling tools
15.3.4. Protection of the environment

Appendix 1. Glossary of Symbols Used

Appendix 2. Glossary of Horizontal Drilling

Bibliography

Index