A variety of methods and machinery used in drilling tunnel

Tunnelis a horizontal or almosthorizontal underground corridor that From both sides or one side is connected with the open air. The world's oldest known tunnel is in Mesopotamia which dates back to about 4000 years ago. Tunnels made in recent years are classified into three general categories tunnels, transportation, industrial and mining. Type of ground, dimensions tunnel and environmental features are important factors in the design and selection of drilling tunnels. Tunnel digging carried out with hand tools or machines mechanized and in different ways. In mechanized tunnel drilling used a variety of machines such as jumbo drills, boom type machines and tunnel boring machines .In this paper presented a revision in relation to number of tunnel drilling methods in different fields and machines used in each of these methods. © 2017Journals-Researchers. All rights reserved.