As the development of industry, economic growth, and expansion of urban scale are accelerated, efforts to utilize tunnels and underground spaces are increasing due to efficient utilization of the land and environmental conservation. Due to urbanization, the increase in the number of vehicles and population has caused serious traffic problems due to lack of public transportation facilities. Therefore, construction of tunnels in urban areas has been steadily increasing as a solution for such traffic problems.

• Transportation of roads, railways and subways
• Water supply and drainage
• Transportation and underground storage of oil

Shield TBM method

In this method, a cylindrical steel excavating machine with a sharp edge(Shield) is press-fitted into the tunnel face, The tunnel is constructed by digging the inside of the cylinder, supporting the excavation equipment to the wall and segments of the tunnel, moving the cylinder forward, and completing the segment lining behind the shield machine.

• Developed by a tunnel method in aquifer ground such as rivers and sea.
• Compared to NATM and Open TBM, excavation and simultaneous lining are installed,
  thus shortening construction period.
• Widely used recently in urban tunnel construction
• High resistance to external stress due to high arch forming effect on circular cross section
• Simple construction management makes quality control easy
• Minimal manpower is used to reduce safety accidents

The need, experience & level of technology for mechanical excavation(Shield TBM)

Compared to the tunneling method focused on the blasting method, the environmental damage such as noise and vibration can be minimized and High-speed construction in long tunnels can greatly reduce construction cost and construction time. and, In particular, mechanical excavation method is needed because it is considered to be the best tunneling method for improvement of environmental performance, stability and economical efficiency in urban areas.