ABSTRACT

The usage of TBM is growing gradually in South Korea with an increase in tunnel constructions in urban areas. TBM is suitable for tunneling in urban areas, while below the surface of the streets, unexpected anomaly zones exist, such as core stones, weak, mixed, fault and fractured zone, along with numerous obstacles such as water and sewage tunnels, deep foundations, cable tunnels, and metro lines. Therefore, it is important to predict ground conditions ahead of the TBM face for safe and economic tunnel construction. In this study, we developed a method to predict ground conditions ahead of the TBM face using electromagnetic waves. Unknown parameters such as ground conditions (size, state, location of anomaly) can be predicted from multiple measurements via back analyses. The developed method was verified through field tests.