Pipe Replacement Method without any digging

1. By Farhad Khazaeli
Fall 2014

2. Australasian society for trenchless technology (astt)

3.  Pipe bursting is trenchless methods used to replace existing
pipelines in the same alignment without physically removing
the existing pipeline.
 Pipe bursting was first developed in the United Kingdom in
the late 1970s by D. J. Ryan & Sons
 This method was patented in the United Kingdom in 1981
and in the United States in 1986; but expired in April 2005.
Najafi, 2010

4.  Pipe bursting typically involves insertion of a cone-shaped
bursting head into an existing
 The base of the cone is larger than the inside diameter of the
existing pipe and slightly larger than the outside diameter
 The back end of the bursting head is connected to the new pipe
and the front end is attached to a cable or pulling rod
 The new pipe and bursting head are launched from the insertion
shaft and the cable or pulling rod is pulled from the pulling shaft
Najafi, 2010

5.  Pipe bursting is too widely used to replace deteriorated
pipes with new pipes of the same or larger diameter
 Currently, pipe bursting is used to replace waterlines,
gas lines, and sewer lines throughout the world
Najafi, 2010

6.  pulling cable or rod (static method)
 hydraulic source (hydraulic method)
 air compressor (pneumatic method)
Najafi, 2010

7.  The most common pipe-bursting method is the pneumatic system.
 The bursting tool is a soil displacement hammer driven by
compressed air
 The hammer operated at a rate of 180 to 580 blows per minute.
 It is similar to a pile-driving operation, but in a horizontal
orientation.
Najafi, 2010

8. http://budgetsewer.com/
Movie

9. 1. The head is attached to the new pipe,
2. The winch cable is inserted through the existing pipe and attached to the head
3. The air compressor and the winch are set at constant pressure and tension
values.
4. The process continues with operator supervision until the head reaches the
pulling shaft at which point it is separated from the new pipe and retrieved
Najafi, 2010

10. Najafi, 2010

11. the old pipe is burst in two steps:
1. The bursting head is pulled into the existing pipe with a
winch cable, which is inserted from the reception pit
2. The head is expanded laterally to break that pipe. An axially
mounted hydraulic piston drives the lateral expansion head
This method of pipe bursting is not common
Najafi, 2010

12. Najafi, 2010

13.  The cone transfers the horizontal pulling force into a radial force
 The steel rods, each about 4 ft in length, are inserted into the
existing pipe from the pulling shaft.
 A hydraulic unit in the pulling shaft pulls the rods
 The tensile force of a cable compared to a rod section is limited
Najafi, 2010

14.  A form of static pipe-bursting method
 The method for breaking and replacing cast-iron or ductile iron pipes by
longitudinal slitting.
 A splitting wheel or cutting knives, slit the pipe longitudinally at two
more lines along the side of the pipe
 A new pipe of the same or larger diameter may be drawn behind the
splitting tool
Najafi, 2010

15. http://plasticpipe.org/

16. Australasian society for trenchless technology (astt)

17. This method excavates the existing pipe in very fine particles and
Removes the existing pipe rather than displaces them into the
surrounding ground like:
HDD, MTBM, or HAB methods
Najafi, 2010

18. Pipe removal is further divided into several methods:
1. Pipe reaming and impactor methods
2. Pipe eating
3. Pipe ejection or pipe extraction
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19. • Pipe reaming is a pipe replacement technique that uses an HDD
machine with minor modifications.
• Removal of the existing pipe is accomplished by mixing the
ground material with the drilling fluid and transferring it to an exit
point
Najafi, 2010

20. Najafi, 2010

21. 1. The patented impactor method is a system that combines the
HDD method with pipe bursting
2. The bursting head (impactor) receives air through the HDD drill
rod
3. The drill rod is pushed through existing pipe to the next manhole
or exit pit
Najafi, 2010

22. 4. The impactor device, after it is attached to the drill stem and to
the new pipe, is activated and pulled into the existing pipe
5. The impactor system bursts the existing pipe by combined action
of pulling using the HDD rig and hammering with the impactor
device breaking the existing pipe and replacing it with the new
pipe
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24. This method pushes or jacks a new pipe into the existing deteriorated
Pipe
Pipe extraction can remove existing pipes for disposal and replace
them with new high density polyurethane (HDPE) or polyurethane
(PE) pipes
Najafi, 2010

25. 1. The lead a heavy steel guide pipe which maintains the alignment within
the center of the existing pipe
2. The cracker which fractures the existing pipe
3. The cone expander which radially expands the fractured line into the
surrounding soil
4. The front jack, a hydraulic cylinder, which provides axial thrust to the
penetration/compaction pieces
5. The pipe adapter, which provides mating surfaces, linking the new pipe
to the front jack
Najafi, 2010

26. Najafi, 2010

27. http://www.unitracc.com/

28.  The process can potentially be executed by horizontal auger
boring
 Excavates the existing pipe and surrounding soil by using a
rotating cutting head attached to an auger
 Other potential methods of pipe eating are using a modified
version of the MTBM or using pipe ramming equipment
Najafi, 2010

29. youtub
Movie

30.  High and medium-density polyethylene (HDPE or MDPE)
 The main advantages of PE pipes are
 Continuity
 Flexibility
 Versatility
 Smooth interior surface
 Smooth exterior surface
Najafi, 2010

31.  Pipe bursting is most cost advantageous compared to the lining
techniques when:
 There are few lateral connections to be reconnected within a replacement
section
 The existing pipe is structurally deteriorated
 Additional capacity is needed
Najafi, 2010

32.  Much faster
 More efficient
 Often less expensive than open-cut, especially in sewer
applications due to the large depths
 Specific studies in the United States have shown that pipe
bursting cost savings are as high as 44% , with an average
savings of 25 % , compared to open-cut (Fraser et al., 1992)
Najafi, 2010

33.  Insertion and pulling shafts are required, especially for larger bursts
 Excavation for service lateral connections is required
 Expansive soils may cause difficulties
 A collapsed (existing) pipe segment may require excavation at that point
to allow the insertion of pulling cable or rod and to repair pipe sag
 Point repairs with ductile material can interfere with the bursting and
replacement process
Najafi, 2010