1. ABHISHEK S. KULKARNI GOV.POLY.,SOLAPUR. CE-5G(R) TUNNEL BORRING MACHINE project guidance: gaikwad sir 2. TUNNELBORRINGMACHINE 3. TUNNEL BORRING MACHINE 4. CONTENTS Introduction Advantagesof TBM MachinePartsof tbm Economicsof Tunnel Typesof TBM MainBeamTBM EarthPressureBalanceTBM 5. INTRODUCTION: TBMexcavatetunnelswithcircular/ throughvarietyof geologicalconditions.Tunnel diametercanrangefrom1-15m. Oneof thefirstTBMbuiltwasusedfortheconstructionof Hoosactunnel-Railroad tunnelintheNorthernBerkshireto wnsofFloridaandNorthA damsConstructedof castiron, it managedto drill10feetbefore breakingdown. BMsarepreferredinurbantunnellingandundergroundminingoverconventional methods. 6. *Tunnel: - *Artificial underground passageto by pass obstacles safely without disturbing the over burden. *Opento sky passage excavatedthrough hugesoil mass of obstacle in required directions to connect two roads or railways. *Over-ground construction to crossover obstacles withoutdisturbing the natural way belowit. 7. ADVANTAGES OF TBM: Reduced disturbance to the surrounding soil Produce a smooth tunnel wall reducing ventilation requirements Reduce cost of lining Improved personnel safety Working speed-6 times greater Hence, wherever speed and safety becomes the main criteria, use of TBM despite its heavy capital cost is preferred. 8. History of Tunnel Constructed Egyptians and Babylonians –4000 years ago length –910 m ; width –3600 mm ; height – 4500mm Channel Tunnel –linking Britain & France – 1994 length –50 km ; undersea component -39 km Consist of 3 parallel bores of 50 km length interconnected every 375 m by cross passages 9. Economics of Tunneling Nature of Soil Requirements of fill Depth of cut > 18m –tunnelling Desirable when 1. Rapid transport facilities 2. Avoids acquisition of land 3. Shortest route connection 4. Permits easy gradient & encourages high speed 5. On strategic routes 10. MACHINE PARTS: A TBM typically consist of Cutter head Shield-metal cylinder serving as temporary support structure while excavation Trailing support mechanisms •Precast concrete segment handling & installing devices •Conveyor belt system for muck removal •Control Cabin •Supply tanks, exhaust fans etc. 11. Classification of Tunnels Based on purpose Conveyance Tunnels Traffic Tunnels Based on type of material met with in construction Tunnels in Hard Rock Tunnels in Soft materials Tunnels in Water Bearing Soils 12. INVESTIGATIONS Investigations prior to planning Investigations made at time of planning Investigations made at time of construction 13. TYPES OF TBM: - Based on no. of shields used:- 1.Main beam TBM 2.Single shield TBM 3.Double shield TBM Based on the face supporting technique used :- 1.Earth pressure balance TBM 2.Bentonite slurry TBM 3.Compressed air TBM 4.Fluid balance TBM 14. Investigations of Prior Planning's Geological Investigations –relation between bed rock and top soil Morphology, Petrology, Stratigraphy Electrical Resistivity Methods – positions of weak zones -faults, folds and shear zones 15. Investigations made at time of planning Drilling holes by percussion, rotary percussion and rotary Rotary or Rotary Percussion methods –loose soils Rotary Drilling –rocky soils Spacing –300-500m ; reduced to 50-100 m in geologically disturbed areas Lateral Spacing –10-15m from C/L of tunnel Depth –20-50 m deeper than proposed invert level of tunnel 16. *MAIN BEAM TBM* 17. *SINGLE SHIELD TBM* 18. *For detailed undisturbed observations, shafts can be excavated *Shafts –vertical or inclined tunnel excavated to reach and to get information for the area surrounding proposed tunnel and tunnel section *Section of 3m x 1.5 m to 3 m X2m *Minimum depth of excavation *Temporary and Permanent Shafts 19. Setting out of Tunnels Setting Out -Making the centre line or alignment of any construction work on ground Setting out centre line of tunnel by 4 stages: Setting out tunnel on ground surface Transfer of Centre line from surface to underground Underground setting out Underground Leveling 20. Settingout tunnel on ground surface *Running an open traverse between two ends of proposed tunnel 21. Underground Levelling Reduced Levels of X & Y are found Plumb bobs are suspended through X and Y to touch marked points X & Y on invert level of tunnel Plumb bob with wire is spread on ground for comparison with steel tape ( say 8 m) From RL of X, subtract 8 m to get RL of point X on invert Taking this level as BM, leveling is performed underground 22. SHAPE OFTUNNELS *Circular Section: *To withstand heavy internal or external radial pressures *Best theoretical section for resisting forces *Greatest C/s Area for least perimeter Sewers and water carrying purposes 23. Tunnel BORRING MACHINE DETAILS 24. *DOUBLE SHIELD TBM* 25. • Grip per Shield TBM used to create an under ground laboratory within Yucca mountain. • Manufacturer-CTS , Kent Washington • Length-140m, • weight-720tons, • diameter-7.62m • Maximum advance rate-5.3m/hr • Power-12 electric motors generating 3800 HP 26. EARTH PRESSURE BALANCE TBM : Suitable for urban tunnelling Designed for soft ground containing water under pressure Controls subsidence of tunnel face by adjusting the pressure inside cutter head chamber so that it get balanced with outside pressure Working area completely sealed against outside fluid pressure High advance rate ,simple muck removal Limited to 6 or 7 m diameter tunnels 27. THANKYOU