Handbook of Pipe Bursting Practice - Nodig-Bau.de

Handbookof Pipe Bursting Practice

M. Rameil (Editor)3Handbookof Pipe Bursting PracticeVULKANVERLAG

Contents 11ContentsForeword .............................................................................................. 5Foreword .............................................................................................. 7Preface ................................................................................................ 8Acknowledgements ............................................................................ 91. Introduction ...................................................................................... 191.1 Definition of “pipe bursting” ................................................................ 191.2 History of pipe bursting technology .................................................... 191.3 Pipe bursting methods ........................................................................ 261.3.1 Dynamic / pneumatic pipe cracking .................................................... 261.3.2 Static pipe bursting .............................................................................. 271.3.3 Calibre pipe bursting ............................................................................ 281.3.4 Method variants .................................................................................... 292. Application range and methodology of pipe bursting .......... 312.1 Bursting pressure pipes ........................................................................ 312.1.1 Static bursting of pressure pipes (mains) ............................................ 312.1.2 Static bursting of pressure pipes (service pipes) ................................ 332.1.3 Static replacement of pressure pipes (service pipes) – Grundopullsplitting / extracting method ................................................................ 332.1.4 Dynamic / pneumatic pipe cracking of pressure pipes (mains) .......... 352.1.5 Dynamic / pneumatic pipe cracking of pressure pipes(service pipes) ...................................................................................... 362.1.6 Dynamic / pneumatic extraction of steel pipes (potable waterservice pipes) applying piercing tools / impact moles ........................ 372.2 Bursting of non-pressurised (sewer) pipes .......................................... 382.2.1 Static bursting of sewer mains ............................................................ 382.2.1.1 Operating from manhole to manhole .................................................... 382.2.1.2 Operating from manhole to pit ............................................................ 392.2.1.3 Operating from pit to manhole ............................................................ 402.2.1.4 Operating from pit to pit ...................................................................... 412.2.2 Static bursting of sewer laterals .......................................................... 422.2.3 Dynamic / pneumatic pipe cracking of sewer mains .......................... 432.2.3.1 Operating from manhole to manhole .................................................... 432.2.3.2 Operating from manhole to pit ............................................................ 442.2.3.3 Operating from pit to manhole ............................................................ 442.2.3.4 Operating from pit to pit ...................................................................... 462.2.4 Dynamic / pneumatic pipe cracking of sewer laterals ........................ 462.2.5 Calibre pipe bursting ............................................................................ 472.2.6 Bursting drainage pipes on waste disposal sites ................................ 472.2.6.1 General remarks .................................................................................. 472.2.6.2 Pits / manholes .................................................................................... 49

12 Contents2.2.6.3 Pipe bursting process / suitable pipes ................................................ 493. Performing pipe bursting .............................................................. 513.1 Planning phase .................................................................................... 513.1.1 Host pipe .............................................................................................. 513.1.1.1 Pressure pipes ...................................................................................... 513.1.1.2 Sewage pipes ...................................................................................... 523.1.2 New pipe .............................................................................................. 523.1.3 Survey of the underground conditions in the area of the host pipe .... 533.1.4 Bidding process and award of contract .............................................. 553.2 Preparation phase ................................................................................ 563.2.1 Selecting the pipe bursting equipment ................................................ 563.2.2 Determination of the distance to the surface and to existing pipesand structures ...................................................................................... 573.2.3 Determination of individual replacement lengths and launch and exitpit positions .......................................................................................... 583.2.4 Equipment set-up on site .................................................................... 613.2.5 Working pits .......................................................................................... 623.2.6 Taking the host pipe out of service ...................................................... 623.2.6.1 Pressure pipes ...................................................................................... 623.2.6.2 Sewage pipes ...................................................................................... 633.2.7 Preparing the pipe bursting equipment ................................................ 633.2.7.1 Pipe bursting equipment ...................................................................... 633.2.7.2 Dimensioning of the overload protection ............................................ 633.2.8 Incoming control of the new pipe material .......................................... 643.2.9 Obstacles and cleaning ........................................................................ 643.3 Performance phase (pipe bursting process and pipe installation) ...... 643.4 Completing phase ................................................................................ 703.4.1 Tests / Inspection .................................................................................. 703.4.1.1 Pressure pipes ...................................................................................... 703.4.1.2 Sewage pipes ...................................................................................... 703.4.2 Net integration ...................................................................................... 703.4.2.1 Pressure pipes ...................................................................................... 703.4.2.2 Sewage pipes ...................................................................................... 703.4.3 Restoring the ground surface .............................................................. 703.5 Quantity measuring, final account, liability .......................................... 714. Host pipe materials suitable for pipe bursting ...................... 734.1 Gas and water supply pipes ................................................................ 734.1.1 Cast iron pipes (CIP) ............................................................................ 734.1.2 Ductile iron pipes (DIP) ........................................................................ 754.1.3 Steel pipes ............................................................................................ 754.1.4 Polyethylene pipes (PE pipes) .............................................................. 764.1.5 PVC pipes (PVC, UPVC pipes) ............................................................ 774.1.6 Concrete/Reinforced concrete pipes (CP / RCP) ................................ 774.1.7 Asbestos cement pipes (ACP) .............................................................. 774.1.8 Lead pipes ............................................................................................ 78

Pipe Bursting - the Breakthrough in Pipe RenewalIt’s wise to choose the pipe bursting replacement method in cases ofdamaged pipes. With the Grundoburst system (5 models) old pipescan be replaced with new pipes of smaller, equal or larger diameter- up to ND 1000. Why Grundoburst? Because even ductile and greycast iron, steel, plastic and many other pipes can be replacedwith PVC/HD-PE coiled or short pipes. The patented QuickLock ®bursting rods are not screwed but simply clicked together giving hugetime savings plus increased productivity of up to 200 m and more per day.Grundoburst is also suitable for applying the Tight-In-Pipe (TIP) method.All in all MORE than you expect.Grundoburst 400 S Grundoburst 400 G Grundoburst 800 G Grundoburst 1250 G Grundoburst 2500 GTHE ONLY CHOICE FOR PERFECT PIPE INSTALLATIONSGermany:Tracto-Technik GmbH & Co. KGTel: +49 2723 80 80Fax: +49 2723 80 81 80www.tracto-technik.deexport@tracto-technik.deUnited Kingdom:TT UK Ltd.Tel.: +44 1234.342.566Fax: +44 1234.352.184www.tt-uk.cominfo@tt-uk.comUSA / Canada:TT TechnologiesTel.: +1 630.851.8200Fax: +1 630.851.8299www.tttechnologies.cominfo@tttechnologies.comAustralia:TT Asia Pacific Pty Ltd.Tel.: +61 7 3420 5455Fax: +61 7 3420 5855www.tt-asiapacific.cominfo@tt-asiapacific.comFrance:Tracto-Techniques S.a.r.l.Tél.: +33 5.53.53.89.83Fax: +33 5.53.09.39.41www.tracto-techniques.comttf@tracto-techniques.fr

14 Contents4.1.9 Already repaired pressure pipes .......................................................... 794.2 Sewage pipes ...................................................................................... 794.2.1 Vitrified clay pipes (VCP) ...................................................................... 794.2.2 Concrete/Reinforced concrete pipes (CP / RCP) ................................ 804.2.3 Plastic pipes (PE-pipes, PVC-pipes, PP-pipes, GRP) .......................... 814.2.4 Asbestos cement pipes (ACP) .............................................................. 824.2.5 Cast iron pipes / steel pipes ................................................................ 824.2.6 Brick pipe (BP) ...................................................................................... 824.2.7 Already renovated pipes ...................................................................... 825. Suitable new pipe materials ........................................................ 875.1 Pressure pipes ...................................................................................... 885.1.1 Plastic pipes ........................................................................................ 885.1.1.1 Polyethylene pipes (PE) ........................................................................ 885.1.1.2 Cross-linked polyethylene pipes (PE-Xa) ............................................ 935.1.2 Ductile iron pipes (DIP) ........................................................................ 955.1.3 Steel pipes ............................................................................................ 975.2 Non-pressure pipes .............................................................................. 985.2.1 Plastic pipes ........................................................................................ 985.2.1.1 Polyethylene pipes (PE) ........................................................................ 985.2.1.2 Polypropylene pipes (PP) ...................................................................... 1005.2.1.3 Glass-fibre reinforced plastic pipes (GRP) .......................................... 1025.2.1.4 Polyvinylchloride pipes (PVC-pipes) .................................................... 1025.2.2 Ductile iron pipes / Steel pipes ............................................................ 1045.2.3 Vitrified clay pipes (VCP) ...................................................................... 1045.2.4 Concrete / Polymere concrete pipes (CP / PCP) ................................ 1056. Economic efficiency considerations: Comparisonbetween pipe bursting and open trench installations .......... 1076.1 Introduction .......................................................................................... 1076.2 An example - Comparative considerations .......................................... 1106.2.1 Equipment utilisation and number of transports .................................. 1116.2.2 Required construction time .................................................................. 1116.2.3 Occupied traffic areas .......................................................................... 1126.2.4 Factor noise and dust .......................................................................... 1126.2.5 Required quantity of bulk material ...................................................... 1126.2.6 Indirect costs ........................................................................................ 1136.2.6.1 Surface follow-up costs ........................................................................ 1146.2.6.2 Costs caused by traffic disruption ...................................................... 1146.2.6.3 Costs caused by damaged trees and undergrowth ............................ 1146.2.6.4 Costs caused by negative influence on businesses and commerce .. 1146.2.6.5 Follow-up costs caused by health impairment .................................... 1146.3 Conclusion ............................................................................................ 1157. Pipe bursting equipment .............................................................. 1177.1 Introduction .......................................................................................... 117

Contents 157.2 Static pipe bursting .............................................................................. 1177.2.1 Bursting rig (push/pulling device) ........................................................ 1177.2.1.1 Bursting rig for threaded rods or bursting rig for QuickLock rods? .... 1197.2.1.2 Pit launched bursting rig ...................................................................... 1217.2.1.3 Manhole launched bursting rig ............................................................ 1237.2.2 Bursting rods ........................................................................................ 1237.2.2.1 Threaded or QuickLock rods? .............................................................. 1237.2.2.2 Rod feeding magazine .......................................................................... 1267.2.2.3 Special rods .......................................................................................... 1267.2.3 Hydraulic power units .......................................................................... 1277.2.4 Bursting tools ........................................................................................ 1287.2.5 Expanders ............................................................................................ 1307.2.6 Pulling heads ........................................................................................ 1327.2.7 Recovery Tools .................................................................................... 1337.2.8 Short pipe tensioning devices .............................................................. 1337.2.9 Tensile force data loggers .................................................................... 1347.2.10 Cleaning Accessories .......................................................................... 1357.3 Dynamic / pneumatic pipe cracking .................................................... 1367.3.1 Pipe cracking hammer .......................................................................... 1367.3.2 Twin capstan winch .............................................................................. 1387.3.3 Compressors ........................................................................................ 1397.3.4 Pipe cracking tools .............................................................................. 1397.3.5 Expanders ............................................................................................ 1407.3.6 Short pipe tensioning devices .............................................................. 1417.3.7 Air hoses, lubricators, shock valve ...................................................... 1428. Method variations .......................................................................... 1438.1 “Tight-In-Pipe” (TIP) renovation method .............................................. 1438.1.1 General .................................................................................................. 1438.1.1.1 Long and short pipe-lining with annulus to be filled ............................ 1438.1.1.2 Close-fit-lining with pre-fabricated pipes without necessity of fillingthe annulus .......................................................................................... 1458.1.2 Definition of Tight-In-Pipe method ...................................................... 1468.1.3 Field of application .............................................................................. 1478.1.4 “Launch – Exit – Applications” ............................................................ 1488.1.4.1 Operating from manhole to manhole .................................................... 1488.1.4.2 Operating from pit to manhole ............................................................ 1488.1.4.3 Operating from pit to pit ...................................................................... 1498.1.5 Equipment ............................................................................................ 1498.1.6 Pipe materials ...................................................................................... 1508.1.7 Conclusion ............................................................................................ 1518.2 Swagelining .......................................................................................... 1539. International pipe bursting job stories ...................................... 1559.1 Replacement of a cast iron gas main with new PE pipes inDortmund-Nette, Germany .................................................................. 1579.2 Replacement of a cast iron gas main with new PE pipes in a

16 Contentspedestrian zone in Dortmund-Hombruch, Germany ............................ 1599.3 Replacement of cast iron gas mains with PE pipes in California,USA ...................................................................................................... 1619.4 Bursting around the bend: static pipe bursting in New Town,North Dakota, USA .............................................................................. 1639.5 Pipe bursting plays key role in water services upgrade in Sydney,Australia ................................................................................................ 1679.6 Pipe bursting saves historical cultural heritage in Sweden .................. 1699.7 Replacement of a cast iron potable water main with new PE pipes inBangor, Northern Ireland ...................................................................... 1719.8 Replacement of a cast iron potable water pipe with new PE pipes inBourdeilles, France .............................................................................. 1749.9 Replacement of a cast iron potable water pipe with ductile iron pipesin Gladenbach-Erdhausen, Germany .................................................. 1779.10 Replacement of a cast iron spring water pipe with ductile iron pipesin Staufen, Germany ............................................................................ 1819.11 First application of a 2500 kN (250 ton) Bursting Rig in Germanyreplacing a cast iron potable water pipe with a new steel pipe .......... 1869.12 Replacement of a ductile iron potable water – connection lineND 400 (8”) between two Waterworks with new ductile iron pipes inSaarlouis, Germany using Pipe Bursting and Horizontal directionaldrilling .................................................................................................. 1909.13 NIBCO solutions takes on ductile iron splitting in Illinois, USA .......... 1949.14 Combined replacement of a steel gas main and a ductile iron potablewater main with cross-linked Polyethylene pipes PE-Xa in Weilburg,Germany .............................................................................................. 1959.15 Splitting steel water main in California: ARB leads the way ................ 1979.16 Replacement of a steel potable water host pipe with new ductile ironpipes in Flensburg, Germany ................................................................ 2009.17 Static Pipe Bursting at McGuire Air Force Base: Spiniello CompaniesAims High ............................................................................................ 2029.18 Vis-Com, Inc. Sets Static Pipe Bursting Record in Taos,New Mexico .......................................................................................... 2059.19 Replacement of a PE spring water pipe with new PE pipes inUnteregeri (Switzerland) ........................................................................ 2089.20 Pipe cracking in the Swiss rocky mountain area ................................ 2109.21 Mastering Pipe Bursting at Augusta .................................................... 2139.22 Dynamic / pneumatic steel pipe splitting in Siegen-Geisweid,Germany .............................................................................................. 2179.23 Pipe cracking at the Point Reyes National Seashore, California,USA ...................................................................................................... 218

18 Contents9.49 Educating the educated in Cork, Ireland .............................................. 2779.50 Lateral pipe bursting makes the grade in Spokane, WA, USA ............ 2809.51 Replacement of a 125 mm (5“) VCP sewer lateral pipe with 180 mm(7“) PE short pipe in Osnabrück, Germany .......................................... 2829.52 Replacement of a 150 mm (6“) VCP sewer lateral pipe with 160 mm(6“) PVC short pipe in Bornheim, Germany .......................................... 2839.53 Renovation of a 250 mm (10“) VCP sewer pipe with special OD242 mm (9.52”) PP-HM short pipes in Olpe, Germany applying theTight-In-Pipe (TIP) Method .................................................................. 2859.54 Renovation of a 300 mm (12“) VCP sewer pipe with special OD292 mm (11.5”) PP-HM short pipes in Borgholzhausen, Germanyapplying the Tight-In-Pipe (TIP) Method .............................................. 2869.55 Renovation of a 300 mm (12“) VCP sewer pipe with special OD292 mm (11.5”) PP-HM short pipes in Dortmund, Germany applyingthe Tight-In-Pipe (TIP) Method ............................................................ 2899.56 Replacement of a 300 mm (12“) concrete sewer pipe with 280 mm(11”) PP-HM short pipes in Siegburg, Germany applying bothcalibre pipe bursting and HDD ............................................................ 2919.57 Replacement of a 400 mm (16“) concrete waste dump sewer pipewith 500 mm (20”) PE pipes in Winterberg, Germany applying bothdynamic / pneumatic pipe cracking and HDD .................................... 2939.58 High speed trains continue uninterrupted during under rail crossingusing trenchless technology ................................................................ 2969.59 Crossing the Tampines Expressway in Singapore .............................. 29910. Quality Assurance, Quality Control, Testing andInspection .......................................................................................... 30310.1 Background .......................................................................................... 30310.2 Failure prevention ................................................................................ 30310.3 Purpose ................................................................................................ 30410.4 Application assessment ........................................................................ 30410.5 Contractor qualifications ...................................................................... 30510.6 Performance specifications .................................................................. 30610.7 Findings ................................................................................................ 30610.8 Conclusions .......................................................................................... 307Annex 1: Model bidding texts .................................................................... 308Annex 2: Literature ........................................................................................ 334

1. Introduction 191. Introduction1.1 Definition of “pipe bursting”Pipe bursting is a eco-friendly trenchless method which replaces existing host pipesby displacing their fragments into the surrounding soil while simultaneously pulling innew protection or utility pipe of the same or larger diameter into the void created. Theinstallation of new, industrially produced and tested pipes of same or larger size is typicalfor this technology whereby all types of pressure or non-pressure pipes as well asprotection pipes can be replaced and installed. New long and short pipe sections areequally suitable. Pipe bursting can be applied from pit to pit, pit to manhole and manholeto manhole.Caliber pipe bursting of sewage pipes is the installation of new pipes into the hostpipe with the new pipes of slightly smaller outside diameter compared to the internaldiameter of the existing host pipe. Force is only transmitted into the host pipe at damagedpipe sections where the internal diameter is smaller than the expander’s outsidediameter, e.g. pipe deformations or protruding cracks.The expression “Berstlining” or “Burst lining” is common mainly in Germany, and israrely used in other countries. Therefore, this technology is known in English-speakingareas as “Pipe Bursting”, “Pipe Cracking” and “Pipe Splitting”. The expression “PipeBursting” is the general term for this technology, but also refers to the replacement ofbrittle material host pipes like cast iron, clay or concrete using the static method withrods. The dynamic / pneumatic replacement of brittle material host pipes is called“Pipe Cracking”. The term “Pipe Splitting” refers to ductile material host pipes likesteel, plastic or ductile iron. The terms used in English are more exact, because theydo not refer to a “Lining-Process” but to the actual replacement process of “bursting”.1.2 History of pipe bursting technologyPipe Bursting has a long tradition, but would never have been so successful or evenimaginable without piercing tool / impact moling technology and horizontal steel piperamming. The first idea to replace pipes by bursting was elaborated by British Gas andUK´s DJ Ryan engineering company, who on a large scale already applied soil displacementhammers (impact moles) and horizontal ramming machines for trenchlessinstallations of pipes and cables in the early 1980s. Also some contractors with selfFig. 1.1: Layout of a modern pipe bursting process

20 1. IntroductionFig. 1.2:Ryan pipe burstingsystem in the early 1980smade equipment had been using the process as far back as 1975. The term pipe burstingwas not used at this time however contractors were performing this process insome locations, including within the USA and Germany.Since 1981, British Gas and DJ Ryan applied for the first basic method and equipmentpatents in the UK. More patents followed in Europe, USA, Japan and South America.The reason for further developments in the UK was the so-called “King Report”,according to which there was an urgent need for action in replacing thousands of milesof defective cast iron gas pipes installed many years earlier. These replacement programmeswere put into practice in the early 1980s and have been carried out eversince.During the first years, the wider application of pipe bursting outside the UK firstly progressedquite slowly. This was caused by the fact that this technology was patentedby British Gas and DJ Ryan, and British Gas who required technical transfer licencefees from manufacturers and royalties for each installed metre which used this technology.Only a few manufacturers with an eye to the future were willing to commit andto sign licence agreements, which, under these circumstances, sometimes causedsignificant additional operating costs.As pipe bursting process began to develop in the USA, the market that took hold wasthe replacement of sanitary sewer piping. The long term neglect of sewer system assetsin the US prompted the US EPA to require some major US cities to embark on longterm sewer replacement/rehabilitation projects. The City of Houston, Texas is a primeexample of this scenario.Fig. 1.3: “PIM method“ (pneumatic / hydraulic)

1. Introduction 21Fig. 1.4: Brochier pipe cracking method with Grundocrack at the end of the 1980s in GermanyThe first German companies to apply pipe bursting technologysince about 1983 were DIGA in Essen and Brochier inNuremberg. Tracto-Technik (TT Group) took on pilot functionamong machine manufacturers. Australia (1985) and theScandinavian countries Finland (1989), Sweden (1986), Norway(1988) and Denmark (1987) were among the countries inwhich the benefits of pipe bursting were clearly seen fromthe very beginning. Russia followed around 1990 withIreland, France, Argentina, Chile and Brazil following afterwardsin approximately 1995.With the British Gas patents having expired (Europe 2001,USA 2005) and the method having reached a high technologicallevel, pipe bursting has really boomed world-wide.Spain (2000), South Africa (2003) and China (2003) as well asrecently Singapore, Malaysia, Indonesia and India and othercountries are now replacing their pipe networks by mainlyapplying pipe bursting. Even in Cuba, this method has beenused since 2001.Pneumatically and hydraulically driven pipe bursting systemswere already known from the very beginning of the technologydevelopment. Pneumatic machines had been originallyknown as “PIM machines” (PIM = Pipe Insertion Method).[1.1] describe the PIM method as follows:“The PIM machine is characterized by the following components:– construction as cone for the creation of channels withdiameter of a protection pipe to be installed,– compressed air driven,– head cone with moveable blades to be activated externallyvia hydraulic system to burst obstacles like pipefittings and repair collars– rear part with direct towing attachment for the protectionpipe as an integral part of the machine.A further characteristic component of this technology is awinch to guide the PIM machine and to assist the burstingprocess.”At that time, individual pipeline sections to be replaced withthe PIM machine were already up to 100 m (330 ft) in length,whereas, dependent on soil conditions, a bursting processup to 0.5 m/min (1.6 ft/min) could be achieved. It was alreadypossible to replace cast iron pipes up to ND 150 mm (6”).The development of a purely pneumatic Grundocrack burstinghammer considerably improved the efficiency of the PIMmachines. This technology became known as “Pipe Cracking.”

22 1. IntroductionFig. 1.5:Grundocrack burstingblade destroying a pipejointGrundocrack pipe bursting hammers are based on the principle of horizontal rammingmachines. These hammers had a slotted head upon which a bursting blade wasattached. This tool configuration was successfully used for replacement of cast ironpipes. The winch assists the bursting hammer by pulling it, with constant tension,against the host pipe. This enabled a direct force transmission of the percussive pistoninto the host pipe and therefore led to greater efficiency, even when bursting jointsand pipe repair clamps. Since then, it was also possible to replace pipelines up to150 m (490 ft) and up to ND 300 (12”) with bursting times of 1–2 m/min (3–6 ft/min).Grundocrack pipe cracking hammers are successfully used world-wide to this veryday.The first hydraulic pipe bursting machines were equipped with hydraulically expandableand contractible heads in order to displace the host pipe into the surrounding soil.They were already called “static pipe bursting machines” at that time. Currently, thisterm has to be reviewed: These machines actually were “static pipe bursting machineswithout bursting rods”. Since they relied on pipe material, they could only be appliedFig. 1.6:“KM Bursting Robot“

1. Introduction 23Fig. 1.7:OEMmie Award for QuickLock quick connectionbursting rodsin sewage pipes. Among others, these machines were known as “Clearline Expandit”,“KM Pipe Bursting” or “exPress Pipe Bursting”. In the USA, Xpandit was used in Claypipe, Cast Iron and Concrete by the Miller Pipeline Corp. This pipe expansion methoddid not gain much acceptance in practice. Due to its operation in sequences, it couldnot keep up with the efficiency of the dynamic / pneumatic pipe cracking method orthe modern static pipe bursting method with quick connect bursting rods. Also, debrisfrom the broken host pipe and trench bedding often fell behind the interlocking segmentsof the bursting head caused jamming of the bursting tool in the full open positionand consequently operational failures.While the first applications in the UK were limited to cast iron gas pipes, applicationrange (also in other countries) extended very quickly to water and sewage pipes. Alreadythen, polyethylene pipes had been used as replacement host pipes. However,they were often installed into PVC-protection pipes. For the replacement of supplypipes in shallow depths, the bursting systems could be launched and retrieved fromsmall pits. The winch was positioned at the exit pit. The PE-pipes were welded to apipe string and pulled into the protection pipes after the bursting had been completed.Sewer lines at greater depths are being increasingly replaced by pipe bursting as soonas the new equipment technology allowed much smaller and less costly pits, or evenmade pits obsolete. With increasing requirements, the pipe bursting technology madeenormous progress. For example, in order to save manholes in sewage networks, atechnology combining pneumatics and hydraulics was developed which, adapted tothese conditions and thus allowed short pipes to be gradually installed into the damagedpipeline.

24 1. IntroductionFig. 1.8: Grundoburst 2500GIn the 1990s the pipe bursting technology range was enriched by a modern variation,the static pipe bursting method with bursting rods. In the beginning, the technologywas applied with standard round screw threaded bursting rods, e.g. Clearline Maxi -burst or TT UK´s Grundoburst TX. Shortly thereafter, TT Group developed a laddershaped bursting rod with a quick connection which could be connected by a simpleclick instead of being screwed together. These so-called “QuickLock” bursting rods offermany technical and economic advantages which will be explained in detail in thefollowing chapters.During the static pipe bursting process with QuickLock rods, a hydraulically drivenbursting rig firstly pushes the rods through the existing host pipe. After arriving in theexit pit, bursting tool, expander and new pipe are connected to the QuickLock rods.The bursting process and pipe installation is started by pulling back the rods. Rigs developinga pulling force up to 2500 kN (275 US tons) are available. In 2004, Grundoburst2500G (pulling force of 2500 kN / 275 US tons for installing pipes up to1200 mm / 47”) received the Top 100 Award in the USA. This is an annual award forinnovative products in the range of construction machines and accessories. It especiallyhonours products from manufacturers who heavily invest in research and development.Nowadays, pipe bursting is mainly applied from ND 50 (2”) to ND 800 (31”) for gas andwater pipes as well as from ND 50 (2”) to ND 1000 (39”) for sewage pipes.The number of pipelines to be repaired is ever increasing worldwide – e.g. in Germany,important pipeline rehabilitation projects are not carried out due to the devastatingfinancial situation of the municipalities.As much of the US underground infrastructure has reached the end of its design life,many cities are aware that they have a major problem lurking under their streets. Someof these cities have been compelled to take action. Many others are not doing muchuntil there is no other alternative. Raising revenue for these massive projects can actuallybe done fairly easily, by small water rate increases. Unfortunately however, thesewater rate increases become political fodder for local officials who do not want to beseen as the one who raised everybody’s water bill. On the other hand there are somecities that realize their single largest investment is the piping owned by the city. Keep-

1. Introduction 25ing these pipelines modern and sized properly is a good investment for the future of aforward thinking community.Although these problems cannot be resolved completely, economical technologies cancontribute toward repairing at least the worst damages.Pipe bursting is such a technology. According to estimates from Advantica, the pipebursting method has become the most widely applied trenchless pipe replacementmethod with more than 50,000 km (31,000 Miles) worldwide.In general, it has to be decided whether repair, renovation or pipe renewal (replacement)is required. A pipe replacement is necessary:– when repair or renovation is technically or economically inappropriate– when the hydraulic capacity needs to be improved by an increased pipe diameter– when repair or renovation offers only a short term solution with a pipe replacementbeing inevitable– when there is request for a long lasting pipe durability and or a higher product lifespan– when the static loading capacity of the defective pipe would be otherwise negativelyaffectedPipe replacement by open trenching involves traffic impairment, noise- and emissionpollution when breaking open the surface. Also there is a risk of surrounding undergroundpipe damage, soil and groundwater intervention and higher storage, transportand soil removal costs. These drawbacks can be almost completely avoided byreplacing pipes using trenchless technology.With the pipe bursting method, the defective or under dimensioned pipe is crackedwith a burst head and then displaced into the surrounding soil. This creates space forthe new pipe directly proceeding, of same or greater diameter. The pipe bursting techniqueallows the replacement of defective pipelines in the same path without any substantialinfluences on soil and groundwater. Open trenching which requires the breakingup and repairing of valuable surfaces is thereby almost entirely eliminated. In addition,this eco-friendly technique helps to cut down costs considerably. However, likeany technology, pipe bursting also has its limitations:– at this time, the application range is limited to circular existing pipes,– if necessary, the host pipe has to be taken out of service during the bursting process(not necessary e.g. for mains, drainage pipe replacement, etc.),– the course of the host pipe must be usable for the new pipeline (e.g. inclination).Heavily encrusted pipes must be cleaned so that bursting rods can be pushedthrough (static bursting) or respectively the winch rope can be pulled in when(dynamic / pneumatic) pipe cracking,– the soil surrounding the host pipe must be displaceable,– house connections have to be installed using pits. This, however, guarantees a professionaland safe integration,– sharp bends, flanged joints of steel and ductile iron pipes, etc., depending onselection of bursting tools require intermediate pits,– pipe slumps (sags) cannot be removed, however, may be reduced,

26 1. Introduction– a minimum distance has to be kept away from existing parallel or crossing pipes aswell as an adequate cover depth.However, the application of pipe bursting also offers all advantages of a modern,trenchless installation method:– pipe bursting is the installation of new, industrially produced pipes, which may becompromised when installed by open cut methods,– pipe bursting gives a considerable reduction in excavation and road works (almostno traffic disturbance, no annoyance of the public or noise and dust pollution,reduced construction time and the reduction of indirect costs),– high daily output up to 150 m (490 ft) gives a cost-effective replacement and considerablecost-savings compared to open cut,– almost any pipe material available for trenchless installation methods can beinstalled by pipe bursting, e.g. plastic, ductile iron (DIP), steel, fibre glass reinforcedplastic (GRP) and even vitrified clay (VCP) and polymer-concrete pipes (PCP). However,new plastic and ductile iron pipes are most commonly installed with pipebursting,– pipe bursting allows the replacement of almost any host pipe material (some withlimitations),– pipe bursting can be applied for any kind of pipe damage as long as the burstingrods can be pushed in (static bursting) or the winch rope can be pulled in (dynamic/ pneumatic pipe cracking),– no reduction of pipe diameter, up-size of pipe diameter is possible,– preparation of the host pipe, like high-pressure cleaning, removal of debris andblockages are not necessary (but may possibly be necessary for other reasons),– considerably less danger of unintended ground settlement compared to open cut,– applicable for pipes in sloped areas and areas with trees, shrubbery and the like,– installing short pipes, bursting is possible from manhole to manhole (manholediameter min. 1000 mm / 39”),– pipe bursting can also be used for the replacement of laterals,– pipe bursting is controlled and described by worldwide standards, norms andregulations.1.3 Pipe bursting methodsModern pipe bursting systems are mainly distinguished by the kind of force transmission.Beside that, methods are also distinguished by their type of propulsion.1.3.1 Dynamic / pneumatic pipe crackingDynamic cracking (also referred to as pneumatic pipe cracking) is assisted by aportable hydraulic winch. A dynamic / pneumatic cracking hammer based on a piercingtool / impact mole or horizontal ramming hammer is used to break and displace thehost pipe. The bursting tools are arranged at the front or rear end (depending on job)of the bursting hammer and transmit the ramming energy into the host pipe and crackit. The following expander displaces the burst fragments of the host pipeinto the surrounding soil and enlarges the void so that a new pipe of the same orlarger diameter can be pulled in, simultaneously.

1. Introduction 27Fig. 1.9:Dynamic / pneumaticpipe crackingThe procedure starts, however, with pulling the winch rope into the host pipe using aflexible glass fibre rod. The new pipes are joined outside the pit (e.g. butt-fused polyethylenepipe string). After the new pipe is attached to the cracking hammer and thehammer itself is connected to the air compressor, it is pulled against the host pipe bythe winch.The bursting process commences by starting the compressor. The pulling force of thewinch assists the forward movement and directional stability of the cracking hammer.When the cracking hammer arrives in the exit pit, it can either be removed there orpulled back through the new pipe into the launch pit in case of lack of exit pit space.Dynamic / pneumatic pipe cracking machines are available in various size classes anddesigns for different applications, in the extreme case even host pipes up to ND 1000(39”). The dynamic / pneumatic impact ramming energy for the replacement of a waterpipe ND 100 (4”), for example, causes less soil displacement or vibration than a vibratorycompaction plate.1.3.2 Static pipe burstingSpecial QuickLock, ladder-shape bursting rods support the bursting, displacing andpipe pulling procedure of the static or also called hydraulic pipe bursting.At first, a hydraulically driven bursting rig is positioned inside the exit pit. A flexibleguide rod ensures smooth installation of the bursting rods through the host pipe. Thebursting rods are quickly connected by clicking them together. QuickLock burstingrods are easily and securely linked together, not screwed together like traditional drillrods or other conventional static systems. The QuickLock system speeds the installationprocess as well as the connection procedure. The rods can be quickly added oneat a time at the exit pit as the rods are pushed up the old host pipe. Once at the launchpit, the guide rod is replaced by a bursting tool (e.g. bladed bursting head, roller bladecutters), expander and new pipe.The entire configuration is then pulled back by the hydraulic bursting rig through thehost pipe towards the exit pit. While pulling back the bursting rods into the direction of

28 1. IntroductionFig. 1.10:Static Pipe Burstingthe exit pit, the bursting tool fragments the host pipe. The expander following thebursting tool displaces the fragmented host pipe radially into the surrounding soil sothat a new pipe of the same or larger diameter can be pulled in, simultaneously.To save manholes or in case there is lack of space on the surface when burstingsewage pipes, it is possible to use special mini-bursting rigs that even fit into manholesof 1000 mm (39”) diameter or larger. If, in addition, short-pipes are used, launch andexit pits are completely unnecessary. Laterals, however, have to be re-connected withminimal digging methods e.g. Suction Excavation.1.3.3 Calibre pipe burstingCaliber pipe bursting is an alternative to cured-in-place or lining methods when the hydrauliccapacity of the host pipe allows this small reduction in the replacement pipe diameter.Bursting of the host pipe only occurs (dynamically or statically) where individual,localised damages exist. This method is applied, for example, when damages likelocal deformations, cracks or partial collapses occur, whereas the remaining part of thepipeline shows no or only minimal damages. Moreover, the host pipe should have sufficienthydraulic capacity, that a reduction of diameter by installing a new, slightlysmaller pipe can be accepted from the hydraulic point of view.

1. Introduction 29Progress of work is much better, becausethe cracking hammer / burstingtool is only activated at the actualdamaged pipe areas, while the newpipe is installed into the remainingsection like in a lining process.Restrictions of calibre pipe bursting:– application range limited to circularpipes larger than ND 150 / 6”(short-pipe larger than ND 200 / 8”),– using short-pipes requires a relativelystraight and level host pipelength,– using long pipes requires an installationand machine pit for settingup and removing the bursting rig aswell as for the installation of theFig. 1.11: PE-pipe installed with caliberburstingnew pipe (size dependent on bending radius of new pipe),– Pipe slumps (sags) cannot be removed but may be reduced,– in case partial or total collapse pushing-in of bursting rods respectively pulling-in ofwinch cable is critical.Caliber pipe bursting also offers many advantages:– total restoration of structural load capacity,– minimal reduction of diameter in case appropriate pipe materials with special sizesare chosen,– applicable for damages like deformations, cracks, fractures, breakages, partial collapses,total collapses, slab-outs, etc.,– new pipe with improved hydraulic capacity and reshaping the circular pipe profile incase of deformations and collapses,– when operating from manhole to manhole respectively pit to manhole reduction ofexcavation works is kept to a minimum,– trenchless installation of house connections possible,– short set-up times reduce construction and labour costs.1.3.4 Method variantsIn addition to the two classic methods dynamic / pneumatic and static pipe burstingas well as caliber pipe bursting, further variations have been developed over the years.Some of these will be introduced in chapter 8.References[1.1] Hoeper, G, Jonas, K.: Rohrnetzsanierung in Essen, Germany 3R International Edition January/ February 1986