Jacking Around the Globe | Part 1 1 | Curved Jacking with hPipes D e 2160 in Paris, FR 3 | hCC-GRP Jacking Pipes Premiere in Dubai, AE 4 | hJacking Pipes Down Under 6 | Curved Jacking with hCentrifugally Cast GRP Pipes 8 | Croatia’s Most Challenging Project Realized with hPipes 9 | Singapore’s First Jacking Project with hPipes 10 | Long-Distance Jacking with hCC-GRP Pipes in Ohio, US 11 | Reliable Wastewater Discharge with hPipes in Brno, CZ 12 | hPipes Prove Their Worth in Hungary PipeLine Issue 5/2013 The Société d‘Etudes, de Maîtrise d‘Ouvrage et d‘Aménagement Parisienne SEMAPA (project company for Parisian constructors and road-builders), is coordinating development projects in Paris‘ 13 th arrondissement. In a recent stormwater treatment project on the south bank of the river Seine, 205 m HOBAS GRP Pipes D e 2160 have been jacked beneath the Ivry-sur-Seine dock. SEMAPA’s mandate involves the redevelopment of 130 ha in the Paris Rive Gauche area to create room for housing, offices, trade and commerce, schools, and infrastructure including the extension of the Paris Métro Line 10. One of the projects in this context was the building of a stormwater storage and treatment system at a cost of 7.8 million euro in the Bruneseau Nord district that should clean the stormwa- ter before it is released into the Seine. The system is installed below the Ivry-sur-Seine dock and includes DN 2000 sewer pipes as well as an overflow for cases of flooding of the Seine. The decision to install the pipes by means of microtun- neling was based on various circumstances. To start with, the high volume of traffic on the dock required an approach that would keep disruptions to a minimum. Furthermore, the position of the sedimentation chamber at the beginning of the track and the diffuser shaft at the end required an installation of the pipeline at a depth of 8-10 m on a 205 meter stretch. An open trench installation at this depth would have been quite difficult and very risky: The subsoil below the Ivry-sur-Seine dock is obstructed by beltway overpass piers, a few gas station tanks, and two slurry walls, and the groundwater table varies between 0 and 5 meters. Furthermore, the two already existing shafts lent themselves as thrust and receiving pits for the microtunneling machine. EEngineering GmbH | Pischeldorfer Str. 128 | 9020 Klagenfurt | Austria T +43.463.48 24 24 | F +43.463.48 21 21 | [email protected] | www.hobas.com Curved Jacking with h Pipes D e 2160 in Paris, FR
Transcript
Jacking Around the Globe | Part 1 1 | Curved Jacking with h Pipes De 2160 in Paris, FR
3 | h CC-GRP Jacking Pipes Premiere in Dubai, AE
4 | h Jacking Pipes Down Under
6 | Curved Jacking with h Centrifugally Cast GRP Pipes
8 | Croatia’s Most Challenging Project Realized with h Pipes
9 | Singapore’s First Jacking Project with h Pipes
10 | Long-Distance Jacking with h CC-GRP Pipes in Ohio, US
11 | Reliable Wastewater Discharge with h Pipes in Brno, CZ
12 | h Pipes Prove Their Worth in Hungary
PipeLineIssue 5/2013
The Société d‘Etudes, de Maîtrise d‘Ouvrage et d‘Aménagement Parisienne SEMAPA (project company for Parisian constructors and road-builders), is coordinating
development projects in Paris‘ 13th arrondissement. In a recent stormwater treatment project on the south bank of the river Seine, 205 m HOBAS
GRP Pipes De 2160 have been jacked beneath the Ivry-sur-Seine dock.
SEMAPA’s mandate involves the redevelopment of 130 ha in the Paris Rive Gauche area to create room for housing, offices,
trade and commerce, schools, and infrastructure including the extension of the Paris Métro Line 10. One of the projects
in this context was the building of a stormwater storage and treatment system at a cost of 7.8 million euro in the Bruneseau Nord district that should clean the stormwa-ter before it is released into the Seine. The system is installed below the Ivry-sur-Seine dock and includes DN 2000 sewer pipes as well as an overflow for cases of flooding of the Seine.
The decision to install the pipes by means of microtun-neling was based on various circumstances. To start with, the high volume of traffic on the dock required
an approach that would keep disruptions to a minimum. Furthermore, the position of the sedimentation chamber at
the beginning of the track and the diffuser shaft at the end required an installation of the pipeline at a depth of 8-10 m on
a 205 meter stretch. An open trench installation at this depth would have been quite difficult and very risky: The subsoil below
the Ivry-sur-Seine dock is obstructed by beltway overpass piers, a few gas station tanks, and two slurry walls, and the groundwater
table varies between 0 and 5 meters. Furthermore, the two already existing shafts lent themselves as thrust and receiving pits for the
microtunneling machine.
E Engineering GmbH | Pischeldorfer Str. 128 | 9020 Klagenfurt | Austria
T +43.463.48 24 24 | F +43.463.48 21 21 | [email protected] | www.hobas.com
Curved Jacking with h Pipes De 2160 in Paris, FR
h PipeLine | Issue 5/2013 | Page 02
Under these conditions, the dimensions of the microtunneling equipment and pipes also had to meet given constraints. The GRP Jacking Pipes provided by HOBAS France have a wall thickness of 79 mm, an external diameter of De 2160, and a very high stiffness at a low inside to outside diameter ratio, allowing for an AVN1600 full face excavation machine to be used instead of an AVN2000. Apart from being light in weight and easy to handle, HOBAS GRP Pipes are also particularly abrasion resistant. Thanks to their smooth surface and constant outer diameter, they allow for low jacking forces and high installation rates. In addition to various international certificates, the GRP Pipes provided by HOBAS France are also CSTBat certified, meaning that they comply with the stringent quality standards of the French “Centre Scientifique et Technique du Bâtiment” (Scientific and Technical Center for Civil Engineering).
The challenge was to build a DN 2000 pipeline on a curved jacking drive passing the beltway overpass piers and a few gas station tanks and through two slurry walls: Two horizontal bends at 500 and 400 m radii as well as an altimetric curve for the transition from a 0.5 to 1% incline had to be realized. HOBAS France provided specifically designed pipes in lengths of 2 meters to facilitate the realization of these curves. HOBAS GRP Pipes are ideal for curved jacking drives in that they allow for an even force transmission with-out timber joint packers. The thrust force of the straight run is adjusted in accordance with the radius of the curve. In this project, the allowable thrust forces that were calculated on the basis of the radii equalled 5530 kN and 6549 kN (as compared to 8845 kN on a straight drive).
Thanks to precise timing and coordination of personnel and pipe deliver-ies, the jacking works were completed within two weeks. The construction company Ludwig Pfeiffer Microtunnel chose a boring head that suited the sandy, gravelly clay soil. A special braking system helped regulate the pres-
sure of the water table on the boring head and prevent the pipes from being pushed back out into the thrust pit. Ludwig Pfeiffer’s operators
steered the microtunneling machine all the way to the exit shaft, arriving precisely on target. Thanks to the optimal characteristics of HOBAS Jacking Pipes, the applied jacking force never exceeded 1570 kN and was therefore far below the calculated maximum force. This site is a showcase project for HOBAS France and Ludwig Pfeiffer Microtunnel, who both demonstrated their micro-tunneling expertise and ability to realize world-class projects.
h CC-GRP Jacking Pipes Premiere in Dubai – Trenchless Installation in the United Arab Emirates
The “Nad Al Sheba 4 Sewage & Drainage” project was initiated to provide Nad Al Sheba 4 across the Emirates Road to Dubai Academic City and parts of the Dubai Silicon Oasis area with an upstream GRP drainage trunk, large enough to accommodate the current and anticipated flow until 2030. In order to avoid traffic disruptions on the heavily frequented 6 to 16-lane Emirates Road and adjacent service roads, it was decided to opt for trench-less installation. One of these microtunneled sections was realized with HOBAS CC-GRP Pipes.
Along with massive infrastructural developments on the Arabian Peninsula, particularly the United Arab Emirates, Qatar, and Saudi Arabia see a strong tendency to employing non-disruptive trenchless techniques such as pipe jacking when planned pipe routes intersect with busy highways or streets. A premier for Dubai is, however, the installation of HOBAS CC-GRP Jacking Pipes. Their numerous technical as well as economic benefits convinced the contractors to jump on the bandwagon. HOBAS Pipes have after all a proven international track record of over 30 years in the trenchless pipe market in Europe, the US, and Australia.
The small outside to inside diameter ratio of the pipe (60 mm wall thick-ness in this project) allowed the use of an AVN1200 (De 1505 mm) instead of AVN1400 (De 1740 mm) microtunneling machine and besides reduced the excavation material by 26 % in this project. Due to the easy handling of the CC-GRP Jacking Pipes and their push-to-fit jointing system, the micro-tunneling experts only needed a couple of pipes to become familiar with the premiering HOBAS System.
The drive depth of the 3-m-long pipes De 1499 mm in diameter and a stiff-ness of SN 64000 lay around 8.6 meters through hard rock and 3.9 meter water table. Thanks to the products’ smooth almost non-absorbing exterior, light weight, and uniform diameter, microtunneling specialist Al Naboodah jacked the complete CC-GRP Jacking section at an average installation speed of 40-50 mm per minute. The subcontractor was also pleased with the extremely low necessary drive forces of approximately 490 kN equaling about 50 tons for the pipes which were designed for a maximal allowable jacking force of 4822 kN. Even after a five-day break the so-called cold start did not necessitate an increase in force.
The Pilbara Region in north-western Australia was first inhabited by the ancestors of today’s Aboriginal people some 50,000 years ago. Since 2012, HOBAS Jacking Pipes De 2250 are playing an important role as stormwater drainage lines for the emerging mining industry. To the South, in Melbourne, HOBAS also scored with high-quality Jacking Pipes De 427: Here, a HOBAS Sewer System was installed by means of jacking.
In the 1950’s, it was discovered that the Pilbara area is home to one of the world’s largest iron ore deposits. Since then it has been an integral contributor to the Australian economy with the help of mining companies such as Rio Tinto. With most of the ore being ex-ported today, a rail infrastructure and large ports have been built to accommodate the ore transportation. One of the largest of these ports is Rio Tinto’s Cape Lambert. Trains travel in from Rio Tinto mines throughout the region, carrying around 80 million tonnes of iron ore per year into Cape Lambert for processing and ship loading.
Cape Lambert is currently undergoing an upgrade, which will see its capacity more than double by mid 2015. At the project’s completion, an estimated 200 million tonnes of iron ore will be exported per year from this port. An integral part of the upgrade project was the extension of the “Sam’s Creek” drainage lines, which run under the existing rail lines allow-ing the release of stormwater during the wet season. The rail lines needed to stay in constant operation throughout the construction works in order to ensure the continual loading of ships. Stopping the productivity was not an option, making trenchless installation the only choice.
The designer of the new drainage culvert Sinclair Knight Merz planned two rows of 2100 mm internal diameter pipes with approximately 100 meters length each. HOBAS Jacking Pipes with an outside diameter of 2250 mm and a stiffness of SN 32000 were specified for this purpose. With the soil being hard and rocky, the initially calculated jacking force added up to 7850 kN. Thanks to the smooth outer surface of HOBAS Jacking Pipes, the actually applied jacking forces were much lower than expected. The substantially smaller outside diameter as compared to an alternative concrete pipe had the additional benefit of allowing increased ground cover beneath the rail line, reducing both risk and installation time. Furthermore, the lead-time for HOBAS was substantially shorter than that of locally supplied concrete pipe, and given the tight timeframe for the project, HOBAS proved to be the best solution.
The installation set a new record in terms of the largest diameter HOBAS Jacking Pipe ever installed in Australia, and it paved the way for similar projects in the ever-growing mining industry in Australia. The Rio Tinto drainage system was also used as an opportunity for creating cultural awareness: Local artists were invited to paint the HOBAS Pipes in the artistic style of the traditional landowners. The imagery is supposed to bring good fortune to the land and HOBAS Pipes have become truly part of the local landscape.
Year of construction
2012
Construction time
6 months
Total length of pipe
308 m
Pipe specifications
De 2250, PN 1, SN 32000
Client
Rio Tinto
Designer
Sinclair Knight Mertz
Contractor
NRW, Tunnel Boring
Australia
Advantages
Low jacking forces,
small inner/outer
diameter ratio
h Jacking Pipes Down Under h Pipes Jacked at Ports Cape Lambert and Victoria Harbour, AUS
h PipeLine | Issue 5/2013 | Page 05
In another recent project, a HOBAS Sewer Pipeline was jacked for a new residential development right in the heart of Melbourne. The Victoria Harbour project was realized just meters away from the iconic and envi-ronmentally sensitive Yarra River. Having been polluted by contaminated stormwater for years before the government implemented an effective treatment system, the banks of the Yarra River still contain contaminated soil. Since this soil is quite expensive to dispose of, this was a criti-cal point when it came to the choice of a suitable pipe and installation method.
The general ground conditions were also quite problematic: Silty clay and wet sand required a non-porous pipe with a low coefficient of friction to ensure the jacking loads would not build up in case the sticky ground clamps around the pipe. The design engineers and installation contractors evaluated all alternatives and eventually opted for HOBAS Jacking Pipes De 427 SN 100000 with stainless steel couplings: Featuring the largest possible inner diameter in relation to their outer diameter, HOBAS Jacking Pipes kept the excavated soil to a minimum and were also optimal for the difficult soil thanks to their smooth and almost non-absorbing outer surface. Most of the 270 m long pipeline was installed in sections up to 7 m deep with a thrust force of approximately 80 kN, the longest drive was 76 m. Surprisingly enough, the tunnelling contractor encountered an unexpected obstacle during the jacking process: a large timber pile suddenly showed up along the alignment of the jacking track, and there was no other option than to jack the HOBAS Pipes straight through the middle of it. The sewer has been successfully completed, on time and within budget. The build-ers can now carry on with erecting the highly sought after, multi storey apartments that will deliver some of the most beautiful harbour views in Melbourne.
For economic and environmental reasons, curved pipe jacking is increasingly specified by designers and clients. Dividing the drive into straight sections with bends located inside the shafts necessitates the use more numerous and in many cases deeper pits. With curved drives the quantity and the depth of these jacking pits can often be optimized.
However, curved drives require special jacking equipment and of course a suitable pipe system. For the pipeline, curved jacking means there is angular deflection in the joints and eccentric longitudinal loading of the pipes. The loading hast to be considered in particular by the calculation of the maximum allowable angular deflection of the joints and the maximum allowable jacking force on the pipes.
The linear-elastic properties of HOBAS CC-GRP Jacking Pipes allows the pipe to react to eccentric loads by means of spigot deformation. Therefore, the contact between the pipes for the transmission of jacking forces remains at the optimal level until deformation limits are exceeded. The high compressive strength of the material is a further plus in curved jacking. Numerous tests on HOBAS GRP Jacking Pipes have shown, that below the allowable compressive stress the material reacts linear-elastic which is not influenced by frequent cyclic loading or wetness. Therefore, the calculation of the deformation and the allowable jacking force for the curved alignment of centrifugally cast GRP jacking pipes is very accurate and reliable.
Jacking Force CalculationCentrifugally cast GRP jacking pipes have the following properties in axial direction:
Compressive stress in axial direction a = 90 N/mm²Elongation at break in axial direction a = 0.7 %
The allowable jacking force under centric loading can be calculated with the following equation (1):
(1) (2)
AR ........ Cross-sectional area of the pipe wall at the thinnest pointS ........ Material safety (1.75)
As there is always some steering even in planned straight alignments, the jacking force P is a purely theoretical figure that cannot be applied in practice.
For the calculation of the allowable jacking force allP at least the following eccentricity has to be consid-ered.
(3) (4)
P ........ from equation (2)
1111
R
h PipeLine | Issue 5/2013 | Page 06
∆1
P
α
L
For the calculation of Δ1 half the pipe length can generally be taken as the applicable length. Due to linear-elastic spigot deformation 1 the calculation of the allowable jacking force and allowable angular deflection in the joint is done under the assumption of full contact over the complete cross-sectional area of both pipes (no packing rings).
If the angular deflection is exceeded due to steering during pipe jacking, the joint between the pipes will gape and the full contact between the pipes is lost.
To prevent the permissible compressive stress a from being exceeded, the allowable jacking force has to be reduced. The adjusted permissible jacking force V at deflection can be calculated by taking figure 4 into consideration. The allowable angular deflection between the pipes and the permissible jack-ing force is the result of their elastic deformability and the permissible gap in the joint. Figure 4 only applies provided that no wooden packing rings are inserted between the pipes.
h PipeLine | Issue 5/2013 | Page 07
If the pipes are subjected to the eccentric jacking force allP the cross-sectional area of the pipe is deflected in the joint as shown in figure 2, which can be calculated with equation 5 and 6.
(5) (6)
L = Applicable length (usually half of the pipe length)
Figure 3: Spigot deforma-tion under eccentric loading
(7)
P ........ from equation (1)Z = Width of the contact area
The partial deflection caused by the eccentric load V can be calculated as follows:
(8)
The partial gap width Δ2 in the area of the gaping joint is calculated as follows: (9)
The total deflection of the pipe joint is then (10)
or by approximation
(11)
The total gap width Δ in the pipe joint is then
Δ = Δ2r + Δ2l (12) or by approximation
Δ = 2 ∙ Δ2 (13)
Figure 4: Relation between the stress ratio max / o and the ratio Z/D
Figure 5: Spigot deflection with gaping joint
β
αr αl
∆2r ∆2l
∆
L
Z
Year of construction
2011
Construction time
3 months
Total length of pipe
513 m
Diameter
De 2047,
pipe wall thickness 65 mm
Pressure class
PN 1
Stiffness class
SN 32000
Application
Irrigation pipeline
Investor
Hrvatske Vode
Designer
Institut IGD d.d.,
Kršimir Galić d.i.g.
Contractor
Aquaterm d.o.o. Karlovac
Advantages
Short installation time,
low weight, abrasion
resistance, low life cycle
costs
Jacking Beneath Railway and StreetCroatia‘s Most Challenging Project Realized with h Pipes
Slavonia is a region in eastern Croatia and known as the country’s breadbasket. To ensure a successful harvest, a reliable irrigation system is necessary – and this is why 513 m HOBAS Pipes De 2047 have been jacked as part of a large-scale irrigation project.
Croatia’s so far most challenging jacking project realized with HOBAS Pipes by the construction company and jacking expert Aqua-term passes beneath a highway and a railroad line. Three parallel sections were drilled as planned in order to align the jacking pipes ac-curately. Heavy rain and snowfall during the construction works posed a challenge to both the workers and the equipment, but not to HOBAS Pipes, which can be laid regardless of weather conditions. The project attracted strong interest from the entire Alps-Adriatic region: Design, construction, and financial experts from Croa-tia, Bosnia, Serbia, and Slovenia visited the site and were introduced to jacking technologies. The investor is more than satisfied with the unique characteristics of HOBAS Products and the quick instal-lation – as a matter of fact, he is using HOBAS Pipes of the same diameter in a follow-up order for another irrigation project.
Dozens of tests have been performed on centrifugally cast GRP pipes by independent in-stitutions over the past 30 years. They have been carried out on pipe strips and full pipes under centric as well as eccentric loads at the University of Illinois (USA), for instance, the University Bochum (Germany), University Dortmund (Germany), and the laboratory of IKT Gelsenkirchen (Germany). In 2005 at the University of Aachen, tests have been carried out on complete pipes at cyclic angular deflection and cyclic longitudinal load, proving that these pipes react linear elastic under eccentric longitudinal loading. While the
pipe was loaded with longitudinal force and the pipe ends were shifted ±20 cm rectangu-lar to the pipe axis the longitudinal stress and strain was measured in the joints and over
the complete pipe length. Ultimate compressive stress in axial direction at 90 N/mm² and longitudinal elongation at break at 0.7% were verified even under these circumstances.
HOBAS Centrifugally Cast GRP Jacking Pipes have proven their worth on countless curved pipe jacking installations around the world and for more than 15 years.
Our Jacking pipes are produced in diameters from DN 200 up to DN 3600 in unit lengths usually ranging from 1, 1.5, 2, 3, through 6 meters. The pipes are designed either for gravity or for pressure applications up to PN 10 and the coupling of the pipe is available in GRP and stainless steel. The al-lowable jacking force of centrifugally cast GRP jacking pipes depends on the wall thickness, which, thanks to the production process, is designed to suit the project’s requirements.
Premiere in South-East AsiaSingapore‘s First Jacking Project with h Pipes
During the summer of 2013, the very first jacking project with HOBAS Pipes in South-East Asia pushed the envelope of what has been feasible in the region up to now. HOBAS Pipes jacked with traditional Swiss preci-sion impressed the customer with a deviation of just 6 mm over a drive length of 63 m and a record installation speed of 10 cm per minute. In total, 728 m HOBAS Jacking Pipes De 427 to 718, PN 1 were installed.
The Upper Seletar Aerospace Park in Singapore is a former military area that is being converted into an industrial center for the aviation industry. Reliable sewage discharge is important for the new structures and there-fore, the investor chose HOBAS Pipes to connect the area to the existing sewer network. This project presented a first for the Public Utility Board (PUB) as well as for HOBAS: For the first time the PUB opted for HOBAS GRP Jacking Pipes and it was the first jacking project for HOBAS on South-East Asian soil. Due to problems with vitrified clay pipes the Public Utility Board decided to find an alternative material and found it in HOBAS CC-GRP Pipes upon recommendation of contractor Tactic Engineering Pte. Ltd.
Installation works ran smoothly and the client as well as the contractors are very satisfied with the record speed of the installation. Thanks to their light weight and their small outer diameter, HOBAS Jacking Pipes were easy to handle using just a small truck crane. Apart from this, they showed an installation precision that wowed investor and potential cus-tomers alike. In fact, the jacking operator Mr. Tangamani said: “Now I’m convinced to use HOBAS Pipes more often. They are easy and safe to install and the precision even on slopes is incredible. At first I was skeptical because of the relatively thin wall of HOBAS Pipes but they proved to be much stronger even than other pipe materials during jacking.” Numerous poten-tial clients, contractors, and authorities visited the construction site as well and were amazed by the easy handling of HOBAS Products and their fast installation.
Long-Distance Jacking in Ohio Trenchless Installation of Trunk Interceptor with h CC-GRP Pipes, US
The wastewater system of the city Marysville in Ohio serves its growing population and several major industrial firms including the Nestlé Corporation, Goodyear Tire & Rubber Co., and Honda. To meet future wastewater requirements, reduce maintenance costs, and increase the reliability of the system, the city decided to build a new water recla-mation facility in 2008. A new wastewater conveyance system was also planned, with the objective to eliminate pump stations throughout the existing collection system and reduce the number of future pump stations. The city concluded five contracts for this purpose, one of them for a trunk interceptor at a cost of 35 million USD. HOBAS Pipes DN 1535 were used to realize this trunk interceptor sewer: It discharges into a pump station, which conveys the wastewater to the water reclamation facility.
The presence of industrial sites posed challenges to the local engineering company DLZ: Throughout the project area, there was potential for contaminated soil and water. “This was one of the reasons we chose to specify trenchless installation techniques for the major part of the project,” Debarati Bardhan, public works project manager with DLZ explained. The pipe could be jacked below the potentially contaminated soil. Other reasons included the depth of over 12 m, interferences with subsurface utility networks, and issues related to easement acquisition – various open surface and subsurface ease-ments, both permanent and temporary, were necessary for the construction of the new line. By placing the jacking pits outside the possible contamination zones, the construction works were greatly facilitated. Trenchless simply proved to be the most economic and convenient method of installation in every aspect.
Long Jacking Runs Two pipe materials were specified for the trunk interceptor project: Centrifugally cast, fiberglass reinforced plastics and reinforced concrete pipe with internal PVC lining. The DN 1535 CC-GRP Pipes and GRP Fittings provided by HOBAS Pipe USA convinced the investor. “The initial material cost increase of HOBAS Fittings over a concrete alternative was offset by the decreased labor cost due to the easy connection with the supplied couplings,” stated Jake Keegan, Project Manager with Super Excavators, Inc. The fittings were equipped with appropriate stubs to connect the existing lines to the new DN 1535 line.
Super Excavators, Inc. installed 6.2 km of HOBAS CC-GRP Pipes DN 1535 – 1.9 km by open cut and 4.3 km by micro-tunneling methods. The jacking pipes supplied by HOBAS Pipe USA featured an allowable thrust force of 5295 kN and were delivered in 3 m lengths in order to reduce the size of the thrust pit. The 4.3 km long jacking pipeline was installed in 18 drives, the longest one amounting to 321 m, with an aver-age jacking force of 980 kN. For the longer drives, intermediate jacking stations were installed in order to distribute the thrustforce along the pipe string by dividing it into independent sections. The hydraulic jacks were installed inside a steel casing fabricated with the same outside diameter as the pipe. The remote-controlled tunnel bor-ing machine managed the difficult ground composition of cobbles, boulders, gravels, and sticky clays without problems.
Year of construction
2008
Construction time
1 year
Total length of pipe
6.2 km
(4.3 km jacking)
Pipe specifications
DN 1535, PN 1, SN 10000
(direct-buried pipes),
SN 32000 (jacking pipes)
Installation methods
Jacking, open trench
Client
City of Marysville
Designer
DLZ Corporation
Contractor
Super Excavators, Inc.
Advantages
Short pipe lengths,
easy installation
h PipeLine | Issue 5/2013 | Page 11
Year of constrcution
2012 – 2013
Construction time
9 months
Total length of pipe
1265 m
Diameter
De 1280
Stiffness class
SN 64000
Pressure class
PN 1
Application
Sewer pipeline
Client
City of Brno
Contractors
IMOS Brno a.s., Metro-
stav a.s., OHL ŽS a.s.
Advantages
Leak-tight system, cor-
rosion resistant, long life
span, low pipe weight
Optimal Performance Thanks to HOBASOnce the pipeline was installed, a series of tests was conducted to ensure its proper installation and perfor-mance. The construction management checked the entire pipeline for deflection by means of a proof stick with a length equal to 97 percent of the internal pipe diame-ter. “The tests were conducted in accordance with the latest specifications and all results were found to be acceptable and within the limits specified in the con-tract,” stated Bardhan. When the job was completed, all parties were pleased with the project’s success.
Reliable Wastewater Dis- charge with h Pipes Major investment in sewer system in Brno, CZ
HOBAS GRP Jacking Pipes were also the first choice for interceptor sewer D, which runs along the river Svitava in the Czech city Brno. The pipes’ excellent hydraulic characteristics and the economic and ecologic advantages of trenchless installa-tion, especially as regards the whole product life cycle, convinced the customer. The HOBAS Centrifugal Casting Process makes sure that all pipe characteristics, e.g. stiffness, are perfectly adapted to the planned jacking drives and the related necessary thrust forces. The pipes were jacked at a depth of 7 m and the lon-gest drive with 212 m was realized with a single intermediate jacking station. In order to keep the thrust force as low as possible, the pipes were equipped with injection nozzles and lubricated with bentonite during installation. The 3 m long HOBAS GRP Jacking Pipes De 1280, SN 64000, PN 1 were jacked with an ISEKI jacking machine over a length of 1265 m without problems.
The construction works were completed in March 2013 to the customer’s utmost satisfaction. More than 3400 inhabitants are now served by the new sewer sys-tem and pleased with the reliable discharge of their wastewater.
h Jacking Pipes Prove their Worth in HungaryBudapest and Budaörs Invest in Local Storm- and Wastewater Discharge
On highly frequented roads, at highway crossings, but also in urban areas where under- and overground infrastructure is becoming denser and denser, there is a strong tendency toward trench-less installation of pipes. Also in Hungary HOBAS Jacking Pipes proved to be the best solution in the two following projects.
In Budapest’s 8th area, several collectors were to be installed to transport sewage from the major part of the city to the adjacent treatment plant. The contractor, who is convinced of the unique properties of HOBAS Jacking Pipes from successfully completed projects in the past, opted for HOBAS Pipes De 1720, SN 32000, PN 1. A 33-m-long part was jacked beneath a busy 8-lane road; further 170 meters were installed heading to Rezső Square. Opening a trench for the pipes would have been impossible as the disruptions to traffic and residents due to the lengthy construction time would not have been acceptable.
Inspections of the storm- and wastewater collector in Budaörs in the west of the Hungarian capital Budapest showed that the old concrete sewer called for urgent renewal. Especially heavy rainfalls would overburden the pipe’s capacity. Due to the outstand-ing hydraulic properties and the swift installation, the client opted for HOBAS CC-GRP Jacking Pipes. The pipe coverage near the thrust pit was quite small, around 70 cm. Thanks to trenchless installation, however, traffic disruptions could be completely avoided. Since the route runs beneath the heavily frequented highways M1 and M7, the pipes further scored with their high load capacity. In addition, a PE pipe paralleling the sewer needed to be protected from static and dy-namic loads. For this, the contractor decided to insert the line in a HOBAS Jacking Casing Pipe De 501, SN 320000, PN 1.
The projects were completed to the total satisfaction of everyone involved and now provide for optimal storm- and wastewater discharge in both Hungarian cities.
