Microtunneling and Horizontal Drilling

The International Society for Trenchless Technology or ISTT is an organization founded in 1986 to promote and advance Trenchless Technology. ISTT encourages the formation and affiliation of societies sharing its objectives world-wide. There are now more than 20 such Affiliated Societies in 6 continents. Each is entitled to nominate a Director on the ISTT Board. For efficient day-to-day running, an Executive Sub-Committee is empowered to act for the full Board.

• Preface 17André COLSONIntroduction 19Michel MERMETPART I. MICROTUNNELING 23Chapter 1. Introduction to Guidelines: Subject and Fields of Application 251.1. General introduction of “trenchless technology” 251.2. History and characteristics of microtunneling methods 271.3. Purpose of the guidelines 28Chapter 2. Techniques and Theory of Operation for the Installation of Pipes by Microtunneling 312.1. General information 312.2. Different functions of a boring machine 322.2.1. Mechanized excavation of the soil 322.2.1.1. Blasting the soil 322.2.1.2. Confinement of the face 332.2.2. Discharge of excavated earth (or mucking) 342.2.2.1. Hydraulic mucking 342.2.2.2. Mucking with a screw conveyor 352.2.2.3. Pneumatic mucking 362.2.3. Guidance and trajectory correction 362.2.4. Installation of pipelines by jacking 372.3. Various types of pipes 372.3.1. Materials used 382.3.2. Joints between pipes 382.3.3. Resistance capacity of pipes 39Chapter 3. Summary of Parameters Affecting Work at the Site 413.1. Summary of parameters affecting the microtunneling. 413.1.1. Rate of penetration 423.1.1.1. Duration for pipe jacking only 433.1.1.2. Total duration for the installation of a pipe in the ground 463.1.2. Alignment deviations 463.1.2.1. Human factors 463.1.2.2. Technological factors 483.1.2.3. Factors linked to the soil 503.1.3. Frictional forces 513.1.3.1. Principle of analysis for experimental data 523.1.3.2. Effect of the overcut 533.1.3.3. Impact of the downtimes 543.1.3.4. Impact of lubrication 573.1.3.5. Impact of misalignment 643.1.3.6. Impact of granulometry 643.1.4. Stresses at the head 643.1.4.1. Presentation of general results 643.1.4.2. Influence of blasting and mucking 673.1.4.3. Influence of trajectory deviations 683.2. Description of the main hitches that can occur when constructing a microtunneling site 693.2.1. Blocking of the machine 693.2.1.1. Various boulders and obstacles 693.2.1.2. Excessive friction 703.2.1.3. Abrasiveness of the soil 713.2.1.4. Sticking of clay 723.2.2. Damaged pipes 723.2.3. Surface disturbances 733.2.3.1. Settlement caused by the annular space 743.2.3.2. Instability of the face, poor balancing of the pressure at the face 743.2.4. Excessive roll 75Chapter 4. Guidelines for Investigations 774.1. General approach of the investigations 774.1.1. General objectives 774.1.2. Progress of the investigations 784.1.3. Cost of investigations 794.2. Data to be acquired 804.2.1. Geological configuration of the site 804.2.2. Hydrogeological conditions 814.2.3. Geotechnical characteristics of the ground 814.2.4. Cavities and artificial obstacles 824.2.5. Environmental conditions 824.3. Methodology and means of investigation 824.3.1. Documentary survey 834.3.2. Geophysical investigations 834.3.2.1. Objectives 834.3.2.2. Usefulness of different methods 844.3.2.3. General guidelines 864.3.3. In situ boreholes and geotechnical tests 874.3.3.1. Objectives of boreholes 874.3.3.2. Layout of boreholes 874.3.3.3. Types of in situ tests 874.3.3.4. Guidelines on the choice of boreholes and tests 884.3.4. Geotechnical tests at the laboratory 894.4. Contents of the geological record 89Chapter 5. Guidelines for the Choice of Machines and Attachments 935.1. General information 935.2. The choice of machines according to their mucking process 945.3. Choice of attachments 955.3.1. The heads: opening, cutting tools 965.3.2. The overcut 985.3.3. The crusher 995.3.4. Bore fluids 99Chapter 6. Guidelines for Project Design, Dimensions of Pipes and the Pipe Jacking System 1016.1. Design of shafts 1016.2. Calculation of pipe jacking stresses 1056.2.1. Definition of friction between the soil and the pipes 1056.2.1.1. General definition 1056.2.1.2. Specific friction values 1066.2.2. Experimental results relating to unit friction 1066.2.2.1. Results of the French National Research Project “Microtunnels” 1066.2.2.2. Results of other studies 1106.2.3. Calculation methodology for frictional forces 1116.2.3.1. Verification of the stability of the excavation 1126.2.3.2. Ground convergence effect 1136.2.3.3. Calculation of frictional forces for unstable excavation in granular soil 1146.2.3.4. Calculation of frictional forces for unstable excavation in cohesive soil 1186.2.3.5. Calculation of frictional forces for a stable excavation 1196.2.4. Comparison of various approaches with experimental values 1206.2.4.1. Calculations-measurements comparison: granular soil without lubrication 1206.2.4.2. Calculations-measurements comparison: granular soil with lubrication 1216.2.4.3. Calculations-measurements comparison: cohesive soil without lubrication 1236.2.4.4. Calculations-measurements comparison: cohesive soil with lubrication 1246.2.5. Guidelines for the calculation of pipe jacking stresses 1246.2.5.1. Dynamic friction: non-cohesive soil 1256.2.5.2. Dynamic friction: cohesive soil 1266.2.5.3. Additional friction caused by stoppage in jacking 1286.2.5.4. Stress on the cutter head 1296.2.5.5. Estimate of the maximum pipe jacking stress 1296.3. Calculation of the maximum acceptable thrust by the pipes during jacking 1306.3.1. Calculation principle 1306.3.2. Permissible stress in the pipes 1326.4. Calculation of the cross-section of pipes 1336.4.1. Various verifications of the calculation of the size of pipes 1336.4.2. General calculation principles: basic Terzaghi model 1346.4.3. Vertical loads to the soil alone 1356.4.3.1. The experimental Terzaghi model 1356.4.3.2. The ATV A161 method 1376.4.3.3. Leonards’ model 1376.4.3.4. Guidelines for the calculation of vertical loads 1386.4.4. Horizontal loads of the ground 1406.4.5. Surface loads 1416.4.5.1. Permanent surface loads 1416.4.5.2. Traffic loads 1426.4.6. Water pressure: presence of groundwater 1456.4.7. Permissible stress in the pipes 1476.5. Bore fluids 1486.5.1. General information 1486.5.2. Selection criteria 1506.5.3. Products used 1516.5.4. Recycling and processing 1526.5.5. Implementation at the site 1536.5.6. Slurry treatment: technical and regulatory aspects 1536.5.6.1. General considerations 1536.5.6.2. Current regulations 1566.5.6.3. Lines for removal of drilling residues 1566.5.6.4. Prospects for reclamation 158Chapter 7. Guidelines for the Site Supervision 1597.1. Guidelines for guidance 1597.1.1. Necessity of controlling trajectory deviations 1597.1.2. Guidelines for the measurement of deviations 1607.1.3. Guidelines for the monitoring of deviations 1607.1.3.1. Initial adjustments and starting of jacking 1617.1.3.2. Corrections during jacking 1617.1.3.3. Adjustment of the overcut 1627.2. Guidelines on the drilling parameters 1627.2.1. Avoid instability of the face 1637.2.2. Avoid excessive thrust on the head and the blocking of the cutterhead 1647.2.3. Checking the roll 1647.3. Guidelines on lubrication 1657.4. Guidelines regarding stoppages during jacking1667.4.1. Provision for the increase in the thrust during restarting 1667.4.2. Limit the increase of the thrust during restarting 1677.5. Data acquisition during the project 167Chapter 8. Socio-Economic and Contractual Aspects 1698.1. Social and economic aspects: concept of social cost 1698.1.1. Value of modern urban sites 1708.1.1.1. Total cost of the work 1708.1.1.2. Direct cost 1708.1.1.3. Overhead cost 1708.1.1.4. Social cost 1718.1.2. Traditional urban sites: nuisance factors 1718.1.2.1. Traffic disruption 1718.1.2.2. Damage to the environment 1728.1.2.3. Risk of accidents 1728.1.2.4. Economic impacts 1738.1.3. Reduction in nuisance by trenchless techniques 1748.1.4. Methods for evaluating the social cost 1768.1.4.1. Methods used in a context other than that of urban sites 1778.1.4.2. Approaches as part of urban underground sites 1798.1.4.3. Comparison methodology for the costs of trench and trenchless techniques 1818.1.5. Other suggestions to reduce the social cost 1878.1.5.1. Susceptibility maps 1888.1.5.2. Financial incentives 1888.1.6. Conclusions 1888.2. Contractual aspects: objectives and success factors 1898.2.1. Proper contractualisation of a microtunneling project 1908.2.1.1. Well defined respective roles 1908.2.1.2. Appropriate risk management 1928.2.1.3. Knowledge of the structure and underground use 1958.2.1.4. Suitable allotment and contracting 1958.2.2. Establishment of appropriate tender documents and a consultation regulation 1968.2.2.1. Tender documents based on a defined strategy 1968.2.2.2. Specifications adapted to every item of the tender documents 1978.2.2.3. A properly described project 1978.2.2.4. Correctly sized and adapted products 2018.2.2.5. Well defined and controlled microtunneling procedures 2018.2.3. Presentation of compliant and pertinent offers by the contractor 2028.2.3.1. Appropriate qualifications 2028.2.3.2. Adequate and adapted references 2038.2.3.3. A complete and definite technical submission 204PART II. HORIZONTAL DRILLING 207Chapter 9. Introduction to Guidelines: Purpose and Fields of Application 2099.1. General introduction of “the trenchless technology” 2099.2. History and characteristics of drilling methods 2119.3. Purpose of the recommendations and fields of application 219Chapter 10. Techniques and Principles of Operation for Horizontal Drilling 22310.1. General information 22310.2. Different stages of horizontal drilling 22510.2.1. Pilot drilling 22510.2.2. Reaming 22610.2.3. Guidance and trajectory corrections 22810.2.3.1. Walk-over systems 22810.2.3.2. Downhole systems or wireline steering systems 23010.2.4. Site organization 23010.2.4.1. Administrative authorizations 23010.2.4.2. Access, site installation 23010.2.4.3. Water 23010.2.4.4. Slurry transfers 23110.2.4.5. Work areas 23110.3. Different types of pipes or conduits 23110.3.1. Thermoplastic pipelines 23210.3.1.1. Polyethylene pipes 23210.3.1.2. Polyvinylchloride pipes 23810.3.2. Metal pipelines 24010.3.2.1. Steel pipes 24010.3.2.2. Pipes in ductile cast iron 242Chapter 11. Summary of Parameters Affecting the Start of a Building Site 24711.1. Summary of parameters affecting the execution of horizontal drilling 24711.2. Parameters related to the ground 24711.3. Parameters related to groundwater and soil permeability 24811.4. Parameters related to obstacles 24911.5. Parameters related to the nature of the pipeline to be installed 24911.6. Parameters related to the drive length 24911.7. Parameters related to the radius of curvature 25111.8. Parameters related to the characteristics of the drilling mud 25111.9. Parameters related to the characteristics of the drilling rig 25111.10. Parameters related to the regularity of the profile, the piloting and the guidance 25111.11. Parameters related to preliminary exploration 25111.12. Parameters related to the (overall dimensions) congestion of the site 25111.13. Parameters related to delays 25211.14. Parameters related to weather conditions 252Chapter 12. Guidelines for Explorations 25312.1. General theory of explorations 25312.1.1. General objectives 25312.1.2. Stages of explorations 25412.1.3. Cost of explorations 25412.2. Data to be acquired 25512.2.1. Geological configuration of the site 25512.2.2. Hydrogeological conditions 25712.2.3. Geotechnical characteristics of the soils 25712.2.4. Pockets and artificial obstacles 25812.2.5. Environmental parameters 25812.3. Methodology and means of explorations 25912.3.1. Documentary survey 25912.3.2. Geophysical investigations 26012.3.2.1. Objectives 26012.3.2.2. Advantage of various methods 26012.3.2.3. General recommendations 26312.3.3. Drilling and in situ geotechnical tests 26412.3.3.1. Test drilling objectives 26412.3.3.2. Setting up investigations boreholes 26412.3.3.3. Test drilling methods 26512.3.3.4. Samples for laboratory tests 26712.3.3.5. In situ tests 26812.4. Contents of the geological-geotechnical dossier of a project 269Chapter 13. Guidelines for the Choice of Drilling Rigs and Equipment 27313.1. General information 27313.2. Choice of drilling rigs according to their power 27413.2.1. Mini drilling rigs 27513.2.2. Medium drilling rigs 27613.2.3. Maxi drilling rigs 27613.2.4. Mega drilling rigs 27713.3. Choice of drilling rigs according to their technical characteristics 27713.3.1. Chassis 27713.3.1.1. Base 27713.3.1.2. Trailer 27813.3.1.3. Track mounted chassis 27813.3.1.4. Wheeled chassis 27813.3.2. Transmission of forces 27813.3.2.1. Chain driven 27813.3.2.2. Rack and pinion 27913.3.2.3. Hydraulic jacks 27913.3.3. Power limits 27913.4. Drilling rods 27913.5. Tools 28113.5.1. Wing cutters 28113.5.2. Spiral compactor bells 28213.5.3. Fluted reamers 28213.5.4. Rock reamers 28213.5.5. Barrel reamers 283Chapter 14. Guidelines for a Project Design 28514.1. Basic principles of a pilot pattern 28514.1.1. Rack angle and exit angle 28514.1.2. First and last part of the drilling 28614.1.3. Radius of curvature 28614.1.3.1. Radius of curvature of the pilot hole 28714.1.3.2. Combined radii 28814.1.4. Roofing 28814.1.5. Relation between the diameters of the pipeline and the borehole 28914.2. Drilling plans 28914.2.1. Longitudinal profile 28914.2.2. Plan view 29014.2.3. Cross-sections 29014.2.4. Work site installation plans 29114.2.5. Catenary and launching ramp 29114.3. Design notes 29114.3.1. Calculation for the work stage 29214.3.1.1. Pulling forces at the level of the drilling head 29214.3.1.2. Tractive forces at the level of the drilling machine 29214.3.1.3. Calculation methods of pulling forces 29314.3.1.4. Calculation of the drilling machine dimensions 29314.3.1.5. Supports 29314.3.1.6. Stresses suffered by the tubes 29414.3.1.7. Protection against collapse 29414.3.2. Calculation of operations stage 29414.4. Work planning 29414.5. Drilling fluids 29514.5.1. General information 29514.5.2. Selection criteria 29714.5.3. Products used 29814.5.4. Recycling and processing 29914.5.5. Implementation at the site 30114.5.6. Sludge treatment: technical and regulatory aspects 30114.5.6.1. General considerations 30114.5.6.2. Drilling wastes eliminations solutions 30314.5.6.3. Development prospects 306Chapter 15. Guidelines for the Management of the Site 30715.1. Guidelines on lubrication, drilling fluids 30715.1.1. General information 30715.1.2. Selection criteria 30815.1.3. Products used 30815.1.4. Implementation at the site 30815.1.5. Polluted sites, environment, slurry 30815.2. Recommendations on reaming 30915.2.1. Reaming diameter 30915.2.2. Choice of the reamer 30915.2.3. Multiple bores 31015.2.4. Reaming sequences 31015.2.5. Reaming speed 31215.2.6. Installing a protective sleeve 31315.3. Guidelines on safety and protection of environment 31415.3.1. Safety at the work station (at the site) 31415.3.1.1. Work on inclines 31415.3.1.2. Work on rotating mechanical parts and tools 31415.3.1.3. Risk of slipping increased by the presence of drilling mud 31415.3.1.4. Respiratory risks related to the inhalation of bentonite powder 31515.3.1.5. Handling of loads during lifting (drilling rod, reamers, etc.) 31515.3.1.6. Significant torsional moments during the tightening or loosening of drilling rod/tool unions 31515.3.1.7. Communication between the control cab, the drilling rig and the pipeline side 31515.3.1.8. Work under thoroughfares 31515.3.1.9. Risks of aggressions on underground structures 31515.3.2. Security of machines 31615.3.3. Security of drilling tools 31615.3.4. Protection of the environment 316Appendix 1. Glossary of Symbols Used 319Appendix 2. Glossary of Horizontal Drilling 323Bibliography 333Index 341