North American Special - Trenchless International

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pipe and conduit April 2009 - Trenchless International Pipe and conduit Part one - a brief history and guide The choice of pipe material is an important consideration when designing road, river and rail crossings and other trenchless installations. These materials have evolved to fulfil specific purposes in modern towns and cities. To help planners decide on the most appropriate pipe for the job Trenchless International provides the first in a two part series about the history and uses of pipe. Trenchless techniques minimise disturbance to residents, business and traffic, reduce environmental impacts and deliver long term economic advantages. However, asset managers need to be informed about the characteristics, strengths and weaknesses of the pipe materials most commonly used in trenchless installations. The construction of pipes and underground conduits dates back thousands of years and is one of the earliest forms of civil engineering construction. The Romans developed cement and concrete similar to that used today. They mixed slaked lime with a pozzolanic volcanic ash from Mt Vesuvius to produce cement. The information below provides an overview of the various types of pipe available, history of the technology, the most common trenchless applications and where the technologies is most suitable. For more detailed information, readers should consult the associations and companies involved in the manufacture and distribution of pipe. Don’t miss the next issue of Trenchless International which will feature the second part in our pipe and conduit series, concentrating on the rehabilitation and repair of underground infrastructure. Concrete pipe Trenchless applications: microtunnelling, pipe jacking Best suited for: storm sewer, waste water or culvert projects The oldest recorded modern-day concrete pipe installation is a sanitary sewer constructed in 1842 at Mohawk in New York State, USA. It remained operational for over 100 years. The French were the first to incorporate steel-reinforcement in concrete pipe in 1896. Concrete pipe is a rigid pipe system that is over 85 per cent dependent on the pipe strength and only 15 percent dependent on the strength derived from the soil envelope. Pre-cast concrete drainage products have a reputation for strength and durability. They will not burn, corrode prematurely, deflect or move off grade to reduce hydraulic performance. Steel reinforcement in concrete pipe adds to its inherent strength. The steel is shaped into cages. Concrete pipe is commonly joined using a confined O-ring gasket or profile gasketed joints. Common diameters range from 300 up to 3,600 mm. Bodies such as the American Army Corp of Engineers recommend a design life of 70-100 years for precast concrete pipe. Ductile iron pipe Trenchless applications: microtunnelling, HDD, pipe bursting, jacking and boring Best suited for: water and waste water The strength, durability and long service life of ductile’s predecessor, gray Cast Iron pipe, are widely recognised. The first official record of Cast Iron pipe installation was in 1455 in Siegerland, Germany. In 1664, King Louis XIV ordered construction of a Cast Iron pipe main extending 15 miles from a pumping station at Marlyon-Seine to Versailles to supply water to the fountains and town. This pipe served the palace gardens for more than 330 years. Ductile Iron was introduced to the market place in 1955. Ductile Iron pipe has high tensile strength, good elasticity and excellent ductility, making it suitable for high stress applications and where pressure surge may be experienced. It offers high corrosion resistance; hydraulic flow; high working pressure and ease of installation. Ductile Iron is available in pressure ratings up to 350 psi in all diameters from 75 to 1,600 mm. It is joined by a variety of different rubber-gasketed joints, mechanical joints, flanged joint, grooved or shouldered joints, balland-socket joints are also available. When properly installed Ductile Iron has a design life of over 100 years. Steel pipe Trenchless applications: microtunnelling, directional drilling, pipe ramming Best suited for: gas, water and waste water. Early development and expansion of steel pipe manufacturing was made possible by the development of a process for refining iron into steel. The Bessemer process developed in 1855 and the openhearth process developed in 1861 were both techniques not only made steel, but also made it stronger, more ductile, and more cost effective. It was now possible to cold form steel sheets into large diameter pipes. Virtually all the early steel pipes were produced by rolling lengths of steel plate, usually 4-8 feet long, into cylinders and riveting the seams and joints to fabricate lengths of steel pipe of up to 30 - feet in overall length. The first recorded installation of steel pipe with riveted seams occurred in Railroad Flat, California in 1858. Records show that some installations of steel pipe in San Francisco that were laid in 1863 are still in use today. Steel pipe is joined by welding, threading-and-coupling or compression fittings. Common diameters range from 3 up to 1,500 mm. The design life varies depending upon the size, grade and coating applications. Polyvinyl Chloride (PVC) Trenchless applications: sliplining, HDD, close fit pipe lining Best suited for: water, waste water and storm water Polyvinyl chloride was discovered late in the nineteenth century. Scientists observing the newly created chemical gas, vinyl chloride, also discovered that when the gas was exposed to sunlight, it underwent a chemical reaction (now recognised as polymerisation), resulting in an off-white solid material. But, this material was so difficult to work with that it was cast aside in favour of other materials. Years later in the 1920s, rubber scientist Waldo Semon was hired by BFGoodrich to develop a synthetic rubber to replace increasingly costly natural rubber. His experiments eventually produced polyvinyl chloride. Although product developers began to use PVC in a variety of ways – in shoe heels, golf balls, and raincoats, to name just a few – its application increased significantly during World War II. PVC turned out to be an excellent replacement for rubber insulation in wiring and was used extensively on US military ships. After 1945, its peace-time usage exploded, first used for sanitary sewers in the 1930s. Plastic pipe systems account for over 75 per cent of the pressure reticulation pipelines being installed across Australia today and over 90 per cent of the sewer reticulation pipelines. PVC slipliner pipe has a gasketed joint and close-fit is butt fused. HDD may be butt fused or a gasketed joint locked together with a spline or stainless steel pins. Common diameters for gasketed PVC pipe range from 40 up to 1,500 mm for gravity sewer and up to 1,200 mm for pressure pipe. A properly designed, installed and operated system will last in excess of 100 years. Vitrified clay pipe (VCP) Trenchless applications: microtunnelling, pipe bursting, pilot tube tunnelling, HDD Best suited for: waste water and storm sewers Vitrified clay is a material that arises after firing high quality clay in controlled circumstances at a temperature of approximately 1,200 degrees Celsius. Vitrified clay is chemically and mechanically resistant and also, in part due to its excellent hydraulic characteristics, has a lifespan greater than 100 years. New clay may be differentiated from old clay pipe by factory-applied flexible compression joints, no joint leakage, computerised drying and firing schedules that increases strength and reduce dimensional variation with vacuum de-airing during extrusion producing a denser body. VCP is joined with a compression joint with a low profile stainless steel collar in common diameters of 100 up to 1,200 mm. Project design life is greater than 100 years. E Engineering GmbH Pischeldorfer Str. 128 9020 Klagenfurt | Austria T +43.463.48 24 24 F +43.463.48 21 21 info@hobas.com www.hobas.com CC-GRP Pipe Systems High performance solutions for trenchless and open-dig applications Sewage Potable Water Raw Water & Irrigation Drainage Hydro Power Thermal Power Cooling Industrial Wastewater pipe and conduit April 2009 - Trenchless International 46 47
Record SWP down under Interflow, an Australian pipeline renewal contractor, recently installed the world’s longest and largest continuous spirally wound pipe liner from a fixed winding machine as part of a sewer rehabilitation project in Sydney. PIPE AND conduit April 2009 - Trenchless International High-density polyethylene (HDPE) Trenchless applications: HDD, pipe bursting, microtunnelling, sliplining Best suited for: water and wastewater, natural gas, fibre optics Paul Hogan and Robert Banks discovered crystalline polypropylene, and a similar plastic that could be produced using ethylene in 1931. When Hogan and Banks first created a reaction between ethylene and benzaldehyde using two thousand atmospheres of internal pressure, their experiment went askew when all the pressure escaped due to a leak in the testing container. On opening the tube they found a white waxy substance that looked a lot like some form of plastic. After repeating the experiment, they discovered that the loss of pressure was not due to a leak at all, but was a result of the polymerisation process. The residue polyethylene resin was a milky white, translucent substance derived from ethylene (CH2=CH2). Polyethylene was produced with either a low or high density. Highdensity polyethylene was developed in 1951. HDPE is flexible, tough, lightweight and impact resistant for lower cost installation. HDPE has performed well during earthquakes, tsunamis and corrosive environments. HDPE can be either fused or mechanically joined and is commonly available in diameters 15 to 160 mm. The life span of HDPE pipes is up to 100 years depending on design requirements and water quality. Polymer concrete pipe Trenchless applications: microtunnelling, pipe jacking Best suited for: waste water Polymer concrete is similar to conventional concrete in that it contains selected blends of aggregates and fillers that are held together using a binder. In polymer concrete the binder is high strength, corrosion resistant, thermosetting resin. This resin requires a curing agent which, when combined with the resin, transfers the resin and curing agent from a liquid to a solid that bonds the aggregate, various fillers and internal reinforcement. Advantages of polymer concrete include rapid curing at ambient temperatures, good adhesion to most surfaces, good long term durability with respect to freeze and thaw cycles, good chemical resistance, lightweight and high tensile and flexural. The standard joint for tunnelling and jacking installations incorporates a pushon stainless steel collar in common diameters of 200 up to 2,600 mm. F i b r e g l a s s reinforced pipe Trenchless applications: microtunnelling, jacking, slipling, tunnel lining and casings Best suited for: water, waste water, irrigation and drainage Fibreglass reinforced thermosetting plastic (‘fibreglass’) first became a viable alternative to protected steel, stainless steel and exotic materials in 1950. That year, centrifugal cast fibreglass piping was first used in the crude oil production industry as a solution to corrosion problems. It was during the 1960s that manufacturers began to develop nationally recognised standards and test methods for fibreglass storage and fibreglass piping systems. Fibreglass piping contains glass fibre reinforcement embedded in cured thermosetting resin. This composite structure typically contains additives such as pigments and dyes. By selecting the proper combination of resin, glass fibres, additives and design, the fabricator can create a product that meets the equipment designer’s performance standard. Fibreglass pipe is joined with pushtogether; gasket-sealed joints in common diameters of 450 up to 3,000 mm with larger diameters possible. The design life is in excess of fifty years. This article is intended as a guide only; we recommended readers seek appropriate advice before selecting pipe material. This article was compiled with information from: American SpiralWeld pipe (www.acipco. com/aswp), Oxford Plastics Inc. (www.oxfordplasticsinc.com), Plastic, Pipes and Fitting Association (www. ppfahome.org), American Iron and Steel Institute (www.steel.org//AM), Fibreglass tank and pipe (www. fiberglasstankandpipe.com), Uni-Bell PVC Pipe Association (www.uni-bell.org), Plastic Industry and Pipe Association www.pipa.com.au, American Concrete Pipe Association (www.concrete-pipe.org), Ductile Iron Pipe Research Association (www.dipra.co), Hobas Pipe (www.hobas.com), National Association of Steel Pipe Distributers Association (www.naspd.com) and the National Clay Pipe Institute (www.ncpi.org). The pipe liner was 633 metres long, the equivalent of more than six football fields in length, 2.4 metres in diameter, and weighed almost 100 tonnes. The previous record for the longest continuous spirally wound pipe liner installed from a stationary winding machine was 340 metres of an 800 mm diameter pipe liner. The installation method used by Interflow involved producing an in-situ pipe by spirally winding a composite plastic strip at a fixed diameter within the host pipe. The pipe liner was formed by feeding a profiled composite strip into a hydraulically powered winding machine positioned inside the existing access chamber. Adjacent profile strips were extrusion welded together inside the winding machine to form a high strength, water-tight pipe. As more strip was fed into the machine, the newly formed pipe corkscrewed its way to the downstream access chamber. The total length of 633 metres was achieved over a period of several days. Spirally winding pipes and pipe liners is not new. Various systems and techniques have existed for decades. Up until this point the practical limitation for the maximum length and size of pipe that could be produced was governed by the torque of the winding machine and its ability to overcome the frictional forces of the newly wound pipe as it rotates inside the host pipe. In the last few years, Interflow has perfected a technique for reducing the frictional forces by floating the newly formed pipe while being wound. In doing this, Interflow is able to use the flow inside the pipe to its benefit and obtain the added bonus of not needing to bypass the sewer in the act of renewal. Interflow’s technique involves controlling the water levels inside and outside the liner to achieve optimum buoyancy. In performing this work there was no indication that 633 metres was the limit of the technology. Based on the performance of the machine and the torque readings, Interflow has its sights firmly set on breaking through the one kilometre barrier in the future. This record installation by Interflow is a significant innovation for the trenchless sewer renewal industry not only because of the feat itself but also for the fact that it has opened up the potential for making very long pipelines from a single location, whether for pipe relining or tunnel boring or any other similar application. Interflow has plans to build on this platform and explore further opportunities. In this particular project, installing a pipe liner at this diameter and this length was essential because the distance between successive access chambers was uncharacteristically long. In a sense there were few other options available to reline the pipe, demonstrating once more that the Trenchless Technology industry continues to respond to the ever increasing challenges that the asset owners put to the market. The installation method, as more profile is fed into the winding machine the pipe travels towards the downstream access chamber. By the time it reached its destination 100 tonnes of pipe was all turning at once. The Project The NGRS pipeline is a 2.515 metre diameter concrete sewer that runs from the Sydney suburbs of Landsdowne in the West to Arncliffe in the East. It was constructed in the 1950s and in some parts was gas attacked and in need of rehabilitation. The major challenges for Interflow were firstly to provide a structural pipe liner at such a large diameter and secondly to install a liner from existing access chambers and in continuous lengths between access chambers. In the trenchless sewer rehabilitation market, where the majority of pipe diameters are less than 1 metre, the most commonly used pipe products are made from plastic or resins. At these diameters plastic can provide a cost effective pipe, stiff enough to resist the applied loads. However, as pipe sizes increase beyond 1 metre in diameter, the range of plastic products that can provide a pipe stiff enough to resist the applied loads diminish, making it increasingly difficult to provide a practical and cost-effective liner. Interflow’s product of choice for these large diameter projects is RiblineTM, a unique steel reinforced spirally wound high density polyethylene liner. Ribline was developed by Rib Loc in 2005. A major advantage of Ribline is that the composite action between the steel and the plastic produces a pipe liner with a high strength to weight ratio and gives both the strength of steel and durability of polyethylene. For this application the Ribline pipe liner was designed to the required stiffness by using a specific size of steel reinforcement inside the plastic ribs of the profile that forms the liner. This allowed Interflow to offer its client a strong pipe with a minimum loss of cross sectional area. In fact the hydraulic performance of the lined pipe is actually enhanced as a result of relining. To put the strength to weight ratio of Ribline into perspective, a 1 metre long section of liner at 2.4 metre in diameter weighed only 150 kg. An equivalent concrete jacking pipe at the same diameter and the same strength would have weighed almost 3,000 kg. The steps involved in renewing the pipe include the following. Firstly the existing pipe and conduit April 2009 - Trenchless International 48 49
Page 1 and 2: In this issue | Canada | USA | Japa
Page 3 and 4: Dec Downey Istt Chairman Trenchless
Page 5 and 6: EXECUTIVE DIRECTOR'S REPORT John He
Page 7 and 8: Pipes & People Prime Horizontal pip
Page 9 and 10: Trenchless in Toronto The 2009 Inte
Page 11 and 12: Events ISTT International No Dig 20
Page 13 and 14: projects April 2009 - Trenchless In
Page 15 and 16: Insertion of the liner takes about
Page 17 and 18: Alleviating flooding in Ashbourne S
Page 19 and 20: obotics April 2009 - Trenchless Int
Page 21 and 22: Risky business by Roderick Lovely a
Page 23 and 24: Deterioration Factors Distress Indi
Page 25: environment Supplying the community
Page 29 and 30: north america April 2009 - Trenchle
Page 31 and 32: north america is a biaxial stress,
Page 33 and 34: disc cutter heads to work through t
Page 35 and 36: “We had a very tight window to ge
Page 37 and 38: Undersea HDD rescue in Saudi Arabia
Page 39 and 40: ADVERTISERS INDEX SUBSCRIPTION FORM

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