Geoelectrics-While-Tunneling: Methodology and Performance Aspects

摘要

This paper presents a detailed investigation of electric geophysical techniques that ‘look ahead’rnof the tunnel face during TBM operations for both hard rock and soft ground conditions, called geoelectricswhile-rntunneling. These methods utilize integrated components of the TBM as electrodes and use currentrninjection to ‘illuminate’ the ground ahead of the TBM, identifying changing ground conditions, faults,rngroundwater inflows, boulders, cavities, utilities etc. Classical earth based methodology, called geoelectrics,rnis well established and is briefly presented, where many of its aspects can be translated to geoelectrics-whiletunneling.rnAn overview of geoelectrics-while-tunneling is presented pertaining to its geometry, influences onrnperformance, and its allowable electrical current injection limit, so as to better establish these methods for usernin industry.