1. TBM TUNNEL BORING MACHINE

2. INTRODUCTION A tunnel is an underground passageway, completely enclosed except for openings for egress, commonly at each end. A tunnel may be for road traffic,,canal,hydroelectric station,sewer etc. The Delaware Aqueduct in New York USA is the longest tunnel, of any type, in the world at 137 km (85 mi) 3. REQUIRMENTS OF TUNNEL IT IS VERY USEFUL WHERE BRIDGE FAIL TO FULFILL REQUIRMENTS LIKE IN SEA ,IN URBAN AREA ,AND IN MOUNTAINS. EFFICIENT COPARED TO BRIDGES. IN WAR TIME IT IS MUCH DIFFICULT TO DESTROY A TUNNEL BUT DESTRUCTION OF BRIDGE IS TOO EASY. LOTS OF LAND AND TIME IS SAVED. 4. TUNNEL BORING MACHINE tunnel boring machine (TBM) is a machine used to excavate tunnels with a circular cross section through a variety of soil and rock strata They can bore through anything from hard rock to sand Tunnel diameters can range from a metre to 19.25metre 5. DRILL AND BLAST 1.Before the advent of tunnel boring machines, drilling and blasting was the only economical way of excavating long tunnels through hard rock, where digging is not possible. 2.Even today, the method is still used in the construction of tunnels But the disadvantage is it disturbance the sorroundings 6. HOW DRILL AND BLAST IS BEING DONE 7. HISTORY The first successful tunnelling shield was developed by Sir Marc Isambard Brunel to excavate the Thames Tunnel in 1825 In the United States, the first boring machine to have been built was used in 1853 during the construction of the Hoosac Tunnel. 8. MAIN PARTS OF TBM 9. WORKING OF TBM A TBM is shaped like a tube. At the front is a rotating disk with cutting teeth that can shear through rock The pulverized rock falls to a conveyor belt that carries it to the back of the TBM Hydraulic feet grip the sides of the tunnel and push the machine forward There is also the ability to insert plates to line the interior of the tunnel 10. How its work 11. ADVANTAGE Higher advance rates Continuous operations Less rock damage Less support requirements Uniform muck characteristics Greater worker safety Potential for remote, automated operation. 12. DISADVANTAGE The major disadvantage is the upfront cost TBMs are expensive to construct, and can be difficult to transport. TBM can not move in backward direction TBMs are expensive to construct, and can be difficult to transport. 13. APPLICATION 1.IN ROAD TRAFFICS 2.IN SEWERS 3.IN MININGS 4.IN RAIL TRAFFICS 5.IN HYDROELECTRIC STATIONS 14. CONCLUSION The main purpose for any organisation is that provide safe environment for worker and TBM is more control and safe than drilling and blasting