38. Atal Tunnel: Atal Tunnel (also known as Rohtang Tunnel) is a highway tunnel built under the Rohtang Pass in the eastern Pir Panjal range of the Himalayas on the Leh-Manali Highway in Himachal Pradesh. At a length of 9.02 km, it is the longest tunnel above 10,000 feet (3,048 m) in the world and is named after former Prime Minister of India, Atal Bihari Vajpayee. The tunnel reduces the travel time and overall distance between Manali and Keylong on the way to Leh. Moreover, the tunnel bypasses most of the sites that were prone to road blockades, avalanches, and traffic snarls. ATALTE Earth is excavated to make a railway tunnel. The tunnel is a cylinder of radius 7 m and length 450 m. A level surface is laid inside the tunnel to carry the railway lines. Figure given below shows the circular cross-section of the tunnel. The level surface is represented by AB, the centre of the circle is O and ZAOB = 90°. The space below AB is filled with rubble (debris from the demolition buildings). CE A MOO5333 B How much volume of earth is removed to make the tunnel ? If the cost of excavation of 1 cubic meter is Rs 250, what is the total cost of excavation? (iii) A coating is to be done on the surface of inner curved part of tunnel. What is the area of tunnel to be being coated? Costing of coating is Rs 30 per m². What is the total cost of coating? OR (iv) How much volume of debris is required to fill the ground surface of tunnel ? how much volume of earth is removed to make the tunnel.
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