Assessment of electrical resistivity imaging for pre-tunneling geological characterization - A case study of the Qingdao R3 metro line tunnel

作者：Li, Shucai^*; Xu, Shan; Nie, Lichao; Liu, Bin; Liu, Rentai; Zhang, Qingsong; Zhao, Yan; Liu, Quanwei; Wang, Houtong; Liu, Haidong; Guo, Qin

来源：Journal of Applied Geophysics, 2018, 153: 38-46.

DOI：10.1016/j.jappgeo.2018.03.024

• Tunnel face and borehole electrical resistivity imaging
• Pre-tunneling geological characterization
• Water body detection
• Probe drilling
• Tunnel construction

Water inrush during tunneling is a significant problem in the underground infrastructure construction. Electrical resistivity imaging (ERI) is a technique that can detect and characterize a water body in an open fracture or fault by exploiting the resistivity contrast that exists between the water body and the surrounding materials. ERI is an efficient method for pre-tunneling geological characterization. In this study, a case study is presented in which tunnel-face and borehole ERI (TBERI) is performed by using the probe hole to detect a water body during tunnel construction. The construction site is a metro line site, situated in the city of Qingdao, China.
Unlike the traditional cross-hole observation mode, TBERI only use a single borehole. The installation of injection electrodes inside the probe hole and the installation of measuring electrodes on the tunnel face is proposed as the observation mode. Furthermore, a numerical simulation is carried out before the real field experiment, and the simulation results show that the TBERI is capable of detecting a deeply buried water body. In addition, the water body in the field case is also identified by TBERI. The water body appears as a strongly conductive anomaly relative to the background materials. This study highlights the respective strengths and weaknesses of the TBERI for pre-tunneling geological characterization. This method is a relatively rapid means of investigating the studied area This study clearly demonstrates the suitability of TBERI in a tunneling scenario.

• 出版日期2018-6
• 单位山东大学