pipe jacking
TRANSCRIPT
PIPE JACKING
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Internet DocumentPipe Jacking – Ritchie-Wiki.Available online at http://www.ritchiewiki.com/wiki/index.php/Pipe_Jacking, checked on 2/4/2017.
Internet DocumentPipe Jacking Association Homepage.Available online at http://pipejacking.org/, checked on 2/8/2017.
Internet DocumentWelcome to Civil and Environmental Engineering at the University of Waterloo.Available online at https://uwaterloo.ca/civil-environmental-engineering/, checked on 2/8/2017.
Internet DocumentOngoing & Upcoming Trenchless Projects in India(2016). Available online at http://www.indstt.com/trenchless_projects.html, updated on 12/17/2016, checked on 2/8/2017.
Reference:
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CONTENTS
• Introduction • Brief History• Methodology• Application• Standards• Equipment/Component• Classification• Alternative methods• Pros & Cons
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INTRODUCTION
• Pipe Jacking is the oldest method of trenchless technology.• Pipes are pushed through the ground behind the shield
using powerful jacks.• Simultaneously excavation takes place within the shield.• This process is continued until the pipeline is completed.• The method provides a flexible, structural, watertight,
finished pipeline as the tunnel is excavated.• Thrust wall is provided for the reaction of the jacks.
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Contd.
Figure 1: Pipe jacking process (a) Jacks are pushing pipe(b) Installation of pipeline under a runway.
(a) (b)Source: www.pipejacking.org Source: www.pipejacking.org
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CONTENTS
• Introduction
• Brief History• Methodology• Application• Standards• Equipment/Component• Classification• Alternative methods• Pros & Cons
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BRIEF HISTORY• First mentioned in 1910, USA by Richardson & Mayo.• In 60s, used in UK and APJA(American Pipe Jacking
Association) is formed.• In 70s, process is industrialized in Japan.• In 80s, developed in Europe. (i) 1800mm dia trenchless pipe is laid for 460m in London,1982. (ii) 560m in water bearing sand and gravel, Byles, 1983.
• Komatsu introduced first fully automated machine in 1975 – IRONMOLE
• Today pipe jacking is remotely operated.
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INDIAN HISTORY• First project is of 3.5km in 1998, Mumbai.• In Cuttack 10km is constructed for sewer using
trenchless method.• Other projects of less than 8km is completed in Goa,
Hyderabad, Kolkata, Delhi, Assam etc.• A total of around 100km is build so far using trenchless
methods so far.Ongoing projects-• 55km of interceptor sewer along 3 major drains for
reduction of pollution in Yamuna river at New Delhi.
CONTENTS
• Introduction • Brief History
• Methodology• Application• Standards• Equipment/Component• Classification• Alternative methods• Pros & Cons
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METHODOLOGYPLANNING
PROCEDURE
SPECIFIC FEATURE
PROCESS BASED ON SOIL
PIPE JACKING FORCE
FAILURE
SOLUTION
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PLANING• Understand the site history and potential obstructions.• Look at old aerial photos.• Conduct a geotechnical program.• Locate all existing utilities.• Minimize costs.• Develop the best cross section.• Use the right materials.
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PROCEDURE
• The thrust pit and the reception pit are excavated at the required places.
• Then the thrust wall is set up in the thrust pit according to the requirement.
• In case of mechanized excavations, a very large pit is required.
• But in case of manual excavation, a small pit is enough.• Thrust ring is provided to ensure the even distribution of
stress along the circumference of the pipe.
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Contd.• The number of jacks vary upon the frictional resistance of
the soil, strength of pipes etc.,• The size of the reception pit is to be big enough to receive
the jacking shield.• To maintain the accuracy of alignment a steerable shield is
used during the pipe jacking.• In case of small and short distance excavations, ordinary
survey method is sufficient.• But in case of long excavations, remote sensing and other
techniques can be used.
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Contd.
Figure 2a: Pipe Jacking ArrangementSource: http://www-civ.eng.cam.ac.uk
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Contd.
Figure 2b: Labelled arrangement of pipe jackingSource: www.google.com
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SPECIFIC FEATURES• Simple cyclic procedure.• Utilizes thrust from hydraulic jacks to force the pipe forward• Person have to enter in pipe for excavation.• Excavation can be manual or by machine.• Excavation takes place in front of an articulated shield. > Designed for worker safety. > Shield guided with individually controlled hydraulic jacks.• Practically limited to dia. greater than or equal to 1075mm.• Pipe installation process occurs from entrance and exit
shaft.
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Figure 3: Manual and Machine Excavation
Source: www.civil.uwaterloo.ca
Source: www.civil.uwaterloo.ca
Source: www.civil.uwaterloo.ca
Source: www.civil.uwaterloo.ca
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PROCESS BASED ON SOILUnstable soil• Face excavated simultaneously with the jacking operation.• Minimize over excavation and the risk of face collapse.• After pipe jacked into place hydraulic rams are retracted
and another pipe length is installed.Stable soil• Face excavation may precede the jacking operation.• All spoils removed through the inside of the pipe to the
jacking pit.
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PIPE JACKING FORCE• Force on jacked pipe includes: > Pipe dead weight. > Penetration resistance or face pressure. > Soil-pipe friction.• Other forces like: > Curvature forces. > Soil dead load. > Railway or highway live load.• Jacking force must not exceed allowable pipe
compressive strength .
19Figure 4: Face Resistance
Source: www.youtube.com
20Figure 5: Skin friction and face resistance
Source: www.youtube.com
21Figure 6: Total force is greater than permissible limit
Source: www.youtube.com
22Figure 7: Force distribution with intermediate jack
Intermediate jackSource: www.youtube.com
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FAILURE• Pipe generally fails from the corner first.• Maximum force is acting at the edges due to: > Uneven distribution of jacking force from one pipe to another. > Unavoidable curvature. > Elastic forces from pressure transfer rings at joints.
Figure 8: Failure of pipeSource: www.youtube.comSource: www.youtube.com
24Figure 9: Failure of pipe
Source: www.youtube.com
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POSSIBLE SOLUTIONSolution
Open cut/dig and replace Trenchless
Tunnel & Replace
Jacking Pipe
Tunnel Liner Plate
Slip-lining
Jacking Pipe
Plastic liner
Lining-Rehab
Cured in place
Shotcrete
CONTENTS
• Introduction • Brief History• Methodology
• Application• Standards• Equipment/Component• Classification• Alternative methods• Pros & Cons
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APPLICATION• Larger Diameter Pipe (1050 mm and up).• Lengths can range from 3 to over 200m.• Sewers, and drainage construction.• Gas and water mains.• Oil pipelines.• Industrial pipelines.• Telecommunication.• Pedestrian subways (access tunnels).
CONTENTS
• Introduction • Brief History• Methodology• Application
• Standards• Equipment/Component• Classification• Alternative methods• Pros & Cons
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STANDARDS
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• BS 6164: 2011 – Code of practice for health and safety in tunnelling in the construction industry.
• BS EN 16191 – Tunnelling machinery safety requirements
Table 1: Standards for pipe jackingSource: www.pipejacking.org
CONTENTS
• Introduction • Brief History• Methodology• Application• Standards
• Equipment/Component• Classification• Alternative methods• Pros & Cons
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EQUIPMENT/COMPONENT• Jacking Pit.• Jack.• Pipe.• Thrust Ring.• Thrust wall.• Lubricant.• Intermediate Jack.• Cutting-head.• Pressure Transfer Ring etc.
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JACKING PIT• Jacking pit size is function of Length of pipe segments,
Pipe diameter, Shield dimensions, Thrust wall design, Jack size, Pressure rings and Guide rail systems.
• Pit should be shored using Timber or steel piling.• Placement of concrete slab on the floor is recommended.
(a) (b)
Figure 10: Typical Jacking Pit(a) and (b)
Source: www.civil.uwaterloo.ca Source: www.civil.uwaterloo.ca
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JACK AND PIPE• Number and capacity of jack is a
function of pipe size, length, skin friction, intermediate jacks etc.
It is suggested to provide even number of jacks.
• Pipe should be light weighted, smooth and strong enough to withstand all the forces.
Figure 11a: Jack
Figure 11b: RCP Pipe
Source: www.civil.uwaterloo.ca
Source: www.civil.uwaterloo.ca
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THRUST RING AND THRUST WALL• Thrust ring distributes force
from jack head to pipe edges equally.
A spacer is optional.
• Thrust wall is provided behind the jack to transfer back thrust of jack to earth and preventing jack to sink.
Figure 12a: Thrust Ring
Figure 12b: Thrust Wall
Source: www.google.com
Source: www.google.com
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LUBRICANT AND INTERMEDIATE JACK
• Lubrication is provided at outer edges of pipe using lubricant injection ports at proper interval.
• Intermediate jack is provided in between the entry and exit shaft. Number of intermediate jack depend on pipe length and jack capacity.
IJ must match pipe diameter.
Figure 13a: Lubricant injection port
Figure 13b: Intermediate JackSource: www.civil.uwaterloo.ca
Source: www.civil.uwaterloo.ca
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CUTTING-HEAD AND PRESSURE TRANSFER RING
• Cutting-head or cutter is located at the front of pipe line. It cuts down the soil ahead using mechanical motion into smaller fragments.
• Pressure transfer ring is used in between of two pipe at joints, it distribute the pressure to succeeding pipe equally. It is made either of cork or synthetic material.
Figure 14b: Pressure Transfer Ring
Figure 14a: Cutter-head
Source: www.youtube.com
Source: www.google.com
CONTENTS
• Introduction • Brief History• Methodology• Application• Standards• Equipment/Component
• Classification• Alternative methods• Pros & Cons
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CLASSIFICATION
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Pipe
Jack
ing
can
be c
lass
ified
on
the
basis
of: Pipe Material
Cutter-head
Excavation Technique
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(a) Reinforced Concrete (b) Vitrified Clay (c) Ductile Iron
(d) Fibreglass (e) Steel (f) Composite
Figure 15: Classification on basis of pipe material(a)-(f)
Source: www.civil.uwaterloo.caSource: www.civil.uwaterloo.ca
Source: www.google.comSource: www.google.comSource: www.hobas.com
Source: www.google.com
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(d) Backacters
(a) Open Face Cutter Booms
(e) Pressurized Slurry
(b) Tunnel Boring Machine (c) Earth Pressure Balance
Figure 16: Classification on basis of Cutter-head(a)-(e)
Source: http://rightofway.transportation.org Source: http://rightofway.transportation.org Source: http://rightofway.transportation.org
Source: http://rightofway.transportation.org Source: http://rightofway.transportation.org
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(a) Manual Excavation (b) Machine Excavation
(c) Conveyer belt Excavation (d) Slurry Excavation
Figure 17: Classification on basis of excavation technique(a)-(d)
Source: www.civil.uwaterloo.caSource: www.civil.uwaterloo.ca
Source: www.google.comSource: www.google.com
CONTENTS
• Introduction • Brief History• Methodology• Application• Standards• Equipment/Component• Classification
• Alternative methods• Pros & Cons
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ALTERNATIVE METHODS
Trenchless Piping
Non-steering Methods
Steering Methods
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• Moling/Piercing• Pipe Ramming• Auger Boring• Pipe Jacking
• Micro-tunneling• Horizontal
directional drilling
Generic Size and Length• Method Size(inch) Length(ft)
Moling 2” - 12” 150’Ramming 8” - 72” 300’Auger Bore 8” - 60” 250’Pilot Tube 6” - 42” 300’ Pipe Jacking >42” 1,000’Micro-tunneling 12” - 42” 1,500’HDD 2” - 48” 6,500’Tunneling >60” Any length
Table 2: Compatibility of different methods 41
Source: www.pipejacking.org
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(a) Auger Boring (b) Pilot Tube (c) Horizontal Direction Drilling
(d) Micro-tunneling (e) Pipe Ramming
Figure 18: Alternative methods(a)-(e)
Source: http://rightofway.transportation.org Source: http://rightofway.transportation.org Source: http://rightofway.transportation.org
Source: http://rightofway.transportation.org Source: http://rightofway.transportation.org
CONTENTS
• Introduction • Brief History• Methodology• Application• Standards• Equipment/Component• Classification• Alternative methods
• Pros & Cons46
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ADVANTAGE• It avoids the excavation of trenches.• Quick set-up, timely finish of projects.• Good quality control and good grade of pipe used.• Can be remotely operated.• Versatile in various ground conditions.• Cost efficient for large length pipe.• Small surface settlements.• Reduces disruption to existing services.• Environment friendly.• Less spoil.
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DISADVANTAGE• Costly for small lengths.• Skilled personal is required.• Dewatering of tunnel path is usually required.• Not feasible for nature of soil changes drastically.• Hard rock/Bed rock or very big boulders should not be
present in the path line.
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CLOSING THOUGHTS• Methods still evolving.• Many hybrid methods emerging.• Will never replace traditional open-cut methods;
however, they complement each other.New idea• To identify potential obstructions we can install a
GPR(Ground Penetrating Radar) at cutting head.