TRENCHLESS TECHNOLOGY

Prepared By:

MD AMANULLAH

ROLL NO: 11EDGCE027

EIGHT SEMESTER

DEEPSHIKHA KALA

SANSTHAN GROUP

OF INSTITUTIONS

RAJASTHAN TECHNICAL

UNIVERSITY KOTA

DEEPSHIKHA KALA SANSTHAN

GROUP OF INSTITUTIONS

CONSTRUCTION TECHNIQUES

Guide By:

PROF. JAMBU JAIN (HOD)ASSISTANT PROFESSOR

CIVIL ENGINEERING DEPARTMENT

DKSGI COLLEGE

JAIPUR

CONTENTS

What Is Trenchless Technology?

History

Need Of Trenchless ?

Trenchless methods

New installation

Rehabilitation and Renovation

Techniques of Trenchless Technology

Trenchless Technology In India

Advantages

Disadvantages

Conclusion

References 2

What is Trenchless?

A family of methods, materials, and equipment capable of being

used for the installation of new or replacement or rehabilitation of

existing underground infrastructure with minimal disruption to

surface traffic, business, and other activities.

Trenchless technology is basically making tunnel below the

surface and installing service lines like gas pipes or

telecommunication cables without disruption to flow and

minimum damage to the environment.

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History

Trenchless technology has been around for many decades

Auger or Jack and Bore in use for 40-50 years

Impact moles were populars for street crossings and to go under

rock gardens

Horizontal Directional Drilling (HDD) started to gain popularity

in late 80`s

Address at 1991 ‘ NO DIG’

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Need Of Trenchless ?

Minimal disturbance to traffic

Year around construction

Improved safety

Reduced landscape damage

Minimal disturbance to local business

Improved construction productivity

Can access otherwise inaccessible areas

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The disadvantages and difficulties encountered in conventional

trenching methods have resulted in thinking of the need for

trenchless technology.

The advantages of the trenchless technology are also responsible

for the need of this technology to be adopted in mainly urban

areas

New installationRehabilitation and

Renovation

TRENCHLESS METHODS

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TWO TYPES OF TRENCHLESS TECHNOLOGY

METHODS

New installation

Methods for the installation of a new pipeline or duct, including

dealing with service connections are :

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Augur boring

Impact moling

Micro tunneling

Horizontal Directional Drilling

AUGUR BORING

To excavate the soil, which is

transported by augur flights

operating in a casing the drive

pit.

Range 100 to 1000 mm diaUsed

for installation of steel pipes

and casings, especially under

railways & road embankments

Very economical

It reduces damage to pavements

and disruption to traffic, hence

reduces social costs associated

with pipeline installations

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IMPACT MOLING

Impact moling is a technique in which a percussive mole (soil

displacement hammer) is launched from an excavation to displace

the soil and form a bore.

This method is restricted to relatively small diameter lines in

compressible soil conditions.

The method which forms the bore hole by compressing the earth

that immediately surrounds the compacting device.

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MICROTUNNELING

The micro tunneling boring machine is remote controlled, a laser

guided system is employed, a jacking system is used to thrust, and

continuous pressure is provided to the face of the excavation to

balance groundwater and earth pressures.

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Used to describe remotely

controlled mechanical tunneling

systems.

Used extensively for sewage

work where surface disruption

has to be minimized

Noise levels and traffic

disruptions are minimized

HORIZONTAL DIRECTIONAL DRILLING (HDD)

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Used for installing pressure pipes under major obstacles such as airport runways, rivers, railway tracks and roads.

These are nowadays widely used for installing pressure pipes under major obstacles such a motor way intersections, large rivers and airports runways.

The first stage consists of drilling a small diameter pilot hole along the desired centre line of a proposed line.

In the second stage, the pilot hole is enlarged to the desired diameter to accommodate the utility line and to pull the utility line through the enlarged hole.

As the pilot hole is being drilled, bentonite-drilling mud is pumped down the center of the drill rods. The drill head consists of either a jetting head or drill bit.

Before the start of back reaming the pipeline has to be positioned on rollers in line with the hole to minimize any axial load on the line

Rehabilitation and Renovation

Methods including are:

i. Pipe bursting

ii. Pipe eating

iii. Relining the existing pipes

iv. Localized repair

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PIPE BURSTING

In this method an existing

pipe can be replaced with a

pipeline of the same or

larger dimension without

opening up the ground.

It used where the load on

the system is more than the

existing pipe can handle and

replacement is required.

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PIPE EATING Pipe eating is an online micro tunneled replacement technique.

The existing defective pipeline is crushed and removed through

the new pipeline.

Based on micro tunneling.

Defective pipe excavated together with surrounding ground.

Consists of micro tunneling shield.

Shield has larger diameter than existing pipe.

Pipe fragment can be removed by 2 methods

1.Vacuum excavation

2.Slurry pumping

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Relining the Existing Pipes

This method require access, usually by manholes, at both end

of the pipes.

Pipe is relined at the places where the joints have moved or

sections are missing ,but the passage should be available.

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Localized Repairs

Local defects may be found in pipes are due to cracking

or joint failures.

Chemical grouting with urethane and similar materials

are used in sewer rehabilitation.

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Techniques of Trenchless Technology

A. Augur boring

B. Moling

C. Ramming

D. Directional drilling

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AUGUR BORING

Auger boring is a technique for forming a horizontal bore hole

through the ground, from a drive shaft to a reception shaft, by

means of a rotating cutting head.

The cutting head is attached to the leading end of an auger string.

Spoil is transported back to the drive shaft by the rotation of

helical-wound auger flights within the steel casing pipe. Vertical

control, using a water level, is typical.

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Advantages

The major advantage is that the casing is installed at the same

time as the borehole excavation takes place.

This method can be used wide variety of soil types.

Disadvantages

This method requires different size cutting heads and augur sizes

or each casing diameter, which increases the investment in

equipment.

The investment in bore, pit construction, and the initial setup is

also required.

In case of soils containing large boulders, this method cannot be

used advantageously.

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MOLING

Instead pits are excavated at intervals for the mole to be placed.

The mole is then entered into the earth on the horizontal face at

the bottom of the pit. Destination pits of similar proportions are

also dug.

The mole displaces the soil creating a bore for the new services

to then be pulled through.

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Advantages It is a rapid, economic, and effective method of installing small

diameter lines.

Any type of utility line can be installed using this method.

The stability of the soil around the borehole is increased due to

compaction.

The investment in equipment is minimum.

Disadvantages

Compaction method are limited in their length by reliability because

basic systems are unintelligent, unguided tools that tend to bury

themselves, surface in the middle road or damage exiting utility lines.

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RAMMING

Ramming creates very little displacement in the surrounding

ground.

The pipe is rammed through the soil by using a device attached

to the end of wide to drive the pipe through the soil.

This method is economical for small dia pipelines.

This method is not suitable where there are solid rock formations

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DIRECTIONAL DRILLING (DD)

Directional Drilling makes the impossible possible.

Generally, it is preferred for long line drilling.

Involves steer able for both small and large diameter lines. The major advantage of directional drilling is the speed of installation combined with minimum environmental impact. The disadvantage of directional drilling is that the equipment is of high cost

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Advantages

The major advantage is the speed of installation combined with

the minimum environmental and social impact.

Long and complicated crossings can be accomplished with a

great degree of accuracy.

Sufficient depth can be accomplished to avoid other utilities.

Disadvantages

Special equipment and very high degree of operation skill is

required.

As the cost of equipment and the operation are high, bore length

should be sufficient in order for it to be economical.

Mainly steel pipe is being installed by this method.

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TRENCHLESS TECHNOLOGY IN INDIA

Brihan Mumbai Municipal Corporation for the construction of 3m dia. Tunnel by micro tunneling.

MTNL in Delhi, kolkata installing large telephone cables by T.T.in Delhi 185 k.m line is made by this.

Pipe line laying below river bed is impossible by open trench method, pipe line laying below Hoogly river by this technique is sufficient to say its importance

In Varanasi(u.p) an urgent repair for brick sewers is successfully done by this

In kolkata 700m length and .762 dia. Iron pipe was repaired which started leakage.

Laying of 18’ dia. Pipe of HBJ across yamuna river is accomplished by this technique

1719m gas pipeline was laid 35m below gautam-godavari river in 1994

3 underground crossing of 24’ dia. And 350 long pipes were completed by Indian

Oil Corporation for panipat refinery.27

Advantages Of Trenchless It reduces damages of valuable surface.

It reduces the danger of improperly compacted excavations.

It saves resources.

It is accident free.

It avoids traffic jam.

It makes the use of the line (track) of the old pipe possible.

It saves underground space (pipe busting).

It reduces the impact on the environment.

It provides the hassle-free road surface.

It is possible to lay service lines across railway track, narrow lanes etc. When open trenching is impossible.

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Presence of a canal, pond, river etc. across the root poses no problems to the trench less technology systems.Without disturbing the traffic and life on the surface, the lines can be laid below ground in a much shorter time by using this technology.For replacement, repair and rehabilitation of old water and sewer lines in cities, it is very helpful to use trench less technology without disturbing the normal life on the surface.

Disadvantage of Trenchless As the open trench is going to create obstruction roads, busy areas,

diversions have to be provided before start of any digging work.

As the obstruction is created, the traffic has to be rerouted causing

traffic jams.

Many a time, while cutting deep trenches in congested areas

appear in the adjacent buildings.

While cutting open trenches, trees, shrubs, gardens etc. may have

to be destroyed damaging the environment.

Excavation is not necessary between access points.

Require less space underground, minimizing chances of interfering with existing utilities or abandoned pipes are generally quiet and nondisruptive.

Require less exposed working area & therefore are safer for both workers & the community 30

CONCLUSION

Cost effective

Low labor requirements

Little site restoration required

Environmental friendly

Reduce environment Construction hazards

Reduce noise and air quality impacts

Reduce traffic congestion

Trenchless technology is the new way forward.

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Bibliography

www.groundforce.uk.com/Trenchless+Technology

www.istt.com/guidelines/pipe-jacking-microtunneling

www.trenchlesssolutions.co.uk/services/impact-moling

www.molingsolutions.co.uk/

www.tedberrycompany.com

www.tritonpipelining.com

www.Trechlessonline.Com

www.tttechnologies.com

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Refrences Jagadish Chandra, “Trenchless Technology in India: Need of the

Neww Millennium.” Civil Engineering and Construction Review October 2000- page 48

Maninder Singh, “Techniques of Trenchless Technology In Use In India.” Civil Engineering and Construction Review October 200-page 43

Dr.Neeraja Lugani Sethi, “Pre- Requisites for Trenchless Technology.” Civil Engineering and Construction Review October 2000- page 21

Sarkar A.K, “Trenchless Technology and INDSTT In India.” Civil Engineering and Construction Review October 2000- page 13

Mohammad Najafi, Sanjiv Gokhale, Trenchless Technology, McGraw-Hill Professional Publications.

Steven R Kramer, William Jesse McDonald,James C Thomson,Anintoduction to trenchless technology.

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THANK YOU

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