Construction of Seoul Subway System and Tunnelling Under Han River

摘要

The city of Seoul has been expanding its subway system for the past 25 years which has become a 280km long network consisting of 8 lines carrying more than five million passengers per day. The city is completing the remainder of Line 6,7, and 8 this year and is planning a new 38km long Line 9. Various methods have been used for the construction of these subway lines, and for the crossing of Han river in subway Line 5, twin single track tunnels werebored under the river using the New Austrian Tunnelling Method(NATM). Brief construction history of Seoul subway system is described, and the design and construction of under-river tunnels of subway Line 5 is discussed including the emergency flood gates.