Journal of the Korean Society of Mineral and Energy Resources Engineers ISSN:2288-0291(Print) 2288-2790(Online) 한국자원공학회지

This cable tunnel project between Shihung and Doksan, which consists of 2,703m length of tunnel including 3 shafts (ø15m/1shaft, and ø6.8m/2shafts) based on the KEPCO\'s long term construction-plan to enlarge the transmission capacity in Gumcheon-Ku, Seoul. Through this project, it is possible to increase the capacity of electric-power supply against the increment of power demand in this area and available to solve the habitual overload of electrical power supply. New tunnel could allow to install the 3 power supply lines of 154kV, 4 to 12 power distribution lines of 22.9kV, and 1 bundle of communication set to fulfil the purpose of this project. Most of the mother rocks along the project alignment are composed of gneiss and schist, and the weathering conditions of this area slightly reduced depending on the depth of rocks, but certain unforeseen faults are expected in some areas by the results of geotechnical investigations. Therefore, Shielded TBM was selected to excavate such a poor and discontinued rock conditions in the urban area to avoid the claims of the local residents in the construction lot, and increase the efficiency of construction management, safety, and minimize the construction periods.