Trenchless Technology

TRENCHLESS TECHNOLOGY

GUIDED BY PRESENTED BY Ms. PRAJEESHA.M.P DEEPAK.CLecturer. Semester 7,CivilDepartment of Civil Engineering. Roll No:58

CONTENTS

• INTRODUCTION• TRENCHLESS CONSTRUCTION METHODS• TRENCHLESS RENEWAL METHODS• TRENCHLESS TECHNOLOGY IN INDIA• ADVANTAGES OF TT OVER TRADITIONAL

OPEN CUT TRENCHES• CONCLUSION

INTRODUCTION

• TT techniques include methods of pipeline & utility installations with minimum amount of surface excavation

• TT techniques are mainly divided into two main areas: TRENCHLESS CONSTRUCTION METHODS(TCM) and TRENCHLESS RENEWAL METHODS(TRM)

• TCM includes all methods for new utility & pipeline installations

Continuation. . . .

• TRM includes all methods of renewing, rehabilitating, or renovating an existing old or host pipeline or utility system

• Trenchless construction and renewal project is site specific & successful completion of it is dependent on factors such as accuracy, maximum installation length, diameter range, & type of application

CONSTRENCHLESS TRUCTION METHODS

• Divided into two major categories: - HORIZONTAL EARTH BORING - PIPE JACKING / UTILITY TUNNELING

HORIZONTAL EARTH BORING

• It includes - Auger Boring - Moling - Pipe Ramming - Water Jetting - Microtunneling

AUGER BORING

• Used 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

Fig.1: AUGER BORING MACHINE

MOLING

• Used for laying water pipes • During moling process, a pneumatically

driven machine known as a mole forces its way through the soil along the desired path of the pipe

• Mole is a steel cylinder about 60cm long and 6cm in diameter, works as a pneumatic cylinder with pulsed compressed air causing the head of the mole to repeatedly hammer against the soil in front of the mole

Fig.2: MOLE

PIPE RAMMING

• Used for installation of steel pipes and casings over distances usually upto 30m long and upto 1.5m in dia

• It is also used for shallow installations under railway lines and roads

• It can be applied for horizontal as well as vertical installations

• Method is pneumatic

WATER JETTING

• Method is simple • It uses high speed jet of water to liquefy

and remove soil• Special nozzle is attached to the end of a

solid rod & extended into the bore hole• Disadvantages:- - poor control of overcut - disposal of large quantities of water and muck - possibility of ground settlement

MICROTUNNELING

• Used to construct small tunnels for laying gravity pipe lines

• Microtunnel boring machines are operated remotely

• Operator controls the machine from a control room on the surface of ground

• Most machines also have video cameras set up to give more information

PIPE JACKING

Jacking Procedure:

Fig.4: STEPS IN PIPE JACKING

TRENCHLESS RENEWAL METHODS

• TRM can be categorized into the following types:

- Coatings - Sliplining - Pipe Bursting - Cured-in-place pipe - Grout

COATINGS

• To repair cracks in the original pipe, or to protect it from corrosive wastewaters or mechanical abrasion

• Coating is applied to the interior of the deteriorated pipe manually

• Coatings are applied by spray, brush, trowel, or roller

• Must be applied to clean, dry surface• Advantage is that no extra work or

equipment is necessary

SLIPLINING

• A flexible pipe of slightly smaller dia is slid through an existing pipe

• Used to repair leaks or restore structural stability to an existing pipeline

• Completed by installing a small carrier pipe into a large host pipe grouting the annular space between the two pipes

• Materials used are high density polyethylene, fibre reinforced plastic, polyvinyl chloride

PIPE BURSTING

Fig.5: PIPE REPLACEMENT BY PIPE BURSTING

CURED-IN-PLACE PIPE

• CIPP is typically a flexible tube constructed of non woven polyester felt material impregnated with a resin that hardens after installation

• Water pressure is produced with a stand pipe

A resin saturated, coated filled tube is inverted(left) or pulled (right) into a damaged pipe

Next, hot water or steam is used to cure the resin & form a tight-fitting, jointless & corrosion-resistant replacement pipe Fig.7: CIPP process

GROUT

• Grout is actually a variety of materials used to fill voids, stabilize soil, hold bricks in place, coat cement, & prevent infiltration

• A typical grouting application in new construction is to seal the joints between segmented concrete pipe

• It seal off ground water infiltration in nonpressure pipelines

TRENCHLESS TECHNOLOGY IN INDIA

• Need for adoption of trenchless technology in India

• Trenchless market

DISADVANTAGES OF TRADITIONAL OPEN TRENCH METHOD

• It involves excavation, pipe removal, pipe replacement, backfilling, and site restoration

• Pumping may be required in areas with a high water table

• Using open trench methods to install or repair underground utilities will invariably cause disruption to normal activities

• Traffic may be blocked, surface operations may be interrupted, & an open trench itself presents a danger

BENEFITS OF TRENCHLESS TECHNOLOGY

• 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

CONCLUSION

• Most recent developments in TT is the use of robotics

• Robots are able to enter hazardous environments

• TT robots are able to provide users with digital data

REFERENCES

1. Mohammad Najafi, Sanjiv Gokhale, Trenchless Technology, Mc Graw-Hill Professional Publications.2. Steven R Kramer, William Jesse McDonald, James C Thomson,An intoduction to trenchless technology3. Steve Orchad “Directional Drilling And Assoctated Technolagies” No-Dig International Journal, November 20084. Public Works Technical Bulletin 420-49-10, 28 February 1999.5. Brij D.K.Gunjal, 1996, “Trenchless Technology in India”:366-368.6. www.Trechlessonline.Com7. www.tttechnologies.com

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