APPLICATIONS OF THE TRANSIENT ELECTROMAGNETIC METHOD IN UNFAVORABLE GEOLOGICAL BODIES WITH WATER OR MUD DETECTION

摘要

Experience shows that unfavorable geological bodies containing water or mud in front of the tunnel working face play a great role in the runnel construction. The transient electromagnetic method (TEM) is sensitive to the low resistive bodies. Usually, the unfavorable geological bodies can be considered as a low resistivity interbed as conducting the geological forecast. On the basis of the whole space theory, this paper intends to use the TEM equivalent conductance plane method on the detection of the low resistivity interbed in front of the tunnel working face. This will be done by combining the apparent longitudinal conductance and its differential imaging,. Some characteristics and laws of the detection are concluded through the computation and the analysis, which can be used to guide the actual TEM tunnel geological forecast and improve the precision and accuracy of TEM detection.