Prediction of tunneling hazardous geological zones using the active seismic approach

Abstract

This paper presents a seismic method and a newly developed device to predict the hazardous geological zones ahead of a tunnel face. The equipment used to predict hazardous geological zones consists of three components: the seismic source, the acquisition unit, and the data processing unit. The following features enable this device to be a valuable tool in predicting hazardous geological zones: the precise trigger time detection; the application of semi‐liquid couplant, which improves geophone coupling with the surrounding rock; the filtering of the prominent tunnel acoustic wave interference; and a software package of information on hazardous geological zones. Through extensive detection exercises of hazardous geological zones in the excavations of nearly 100 tunnel projects in China, it has been demonstrated that this device can satisfactorily predict hazardous geological zones, such as faults, water‐bearing zones, karst caverns, etc., within 150 m in front of the tunnel faces.

Locating scatterers while drilling using seismic noise due to tunnel boring machine

“…This method was further developed and commercialized into Tunnel Seismic Prediction TSP 202 system (Dickmann and Sander 1996;Sattel et al, 1996). This method was followed by other seismic-based methods such as True Reflection Underground Seismic Technique (TRUST) (Benecke et al, 2008), the Tunnel Seismic Tomography (TST) (Zhao et al, 2006), and the Tunnel Geological Prediction (TGP) (Jiao et al, 2015). Another technique is the Sonic Softground Probing (SSP), which is a seismic-while-drilling (SWD) method where sources and receivers are located on the cutting wheel of the TBM (Kneib et al, 2000).…”