Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.



Published on


Published in: Engineering


  2. 2. 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
  3. 3. 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. 3
  4. 4. 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’ 4
  5. 5. 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 5
  6. 6. 6  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
  7. 7. New installation Rehabilitation and Renovation TRENCHLESS METHODS 7 TWO TYPES OF TRENCHLESS TECHNOLOGY METHODS
  8. 8. New installation Methods for the installation of a new pipeline or duct, including dealing with service connections are : 8 Augur boring Impact moling Micro tunneling Horizontal Directional Drilling
  9. 9. 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 9
  10. 10. 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. 10
  11. 11. 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. 11  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
  13. 13. 13  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
  14. 14. Rehabilitation and Renovation Methods including are: i. Pipe bursting ii. Pipe eating iii. Relining the existing pipes iv. Localized repair 14
  15. 15. 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. 15
  16. 16. 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 16
  17. 17. 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. 17
  18. 18. 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. 18
  19. 19. Techniques of Trenchless Technology A. Augur boring B. Moling C. Ramming D. Directional drilling 19
  20. 20. 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. 20
  21. 21. 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. 21
  22. 22. 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. 22
  23. 23. 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. 23
  24. 24. 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 24
  25. 25. 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 25
  26. 26. 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. 26
  27. 27. 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 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
  28. 28. 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. 28
  29. 29. 29 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.
  30. 30. 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
  31. 31. 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. 31
  32. 32. Bibliography        www.Trechlessonline.Com  32
  33. 33. 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, Mc Graw-Hill Professional Publications.  Steven R Kramer, William Jesse McDonald,James C Thomson,An intoduction to trenchless technology. 33
  34. 34. THANK YOU 34