Application Study Of The Method Of Transient Electromagnetic In Tunnelling Geological Lead Prediction

With the establishment of blueprint what great development of the western China and totally construction of affluent society, the construction of basic projects such as highroad, railway and water conservancy will be strengthened. Our country with a vast territory , complicate topography and physiognomy, it is inevitable that mountains would be crossed by those life spring projects, so tunnel projects will become the most important constituent in those great projects. Security of the constructors and facility would be intimidated and construction process of the tunnel would be infected by these serious geological disasters such as rock burst, sudden gas outburst, sudden rush of groundwater and transfiguration of inner tunnel resulted from complicate geological conditions the in the construction. Therefore, there is significant theoretical and practical sense to predict and detect the detail engineer hydro-geological conditions, prevent occur of geological disasters by the way of developing studying on geological lead prediction of the forward active face in tunnel construction.In the essay,on the basis of analysis of former studies on the study works on the prediction of tunnel geological lead prediction , with the technology of transient electromagnetic to measure the depth of tunnel was firstly used in geological lead prediction of the forward active face. Firstly, the basic principle of transient electromagnetic was introduced; secondly, the planar imaging method and explain method of transient electromagnetic equivalent lead were studied in the essay; Thirdly, the two-layers and three-layers modes were established and simulated researched respectively towards casual geological environmental physical geography mode; Forthly, based on the detailed characteristics of tunnel projects, the key technology and work method of transient electromagnetic in the lead prediction of tunnel forward active face construction were studied in the essay; Finally, three typical tunnels were chosen as examples of problems such as faults and fissures, classification of wallrock,underground rivers and holes. Which indicated that it is feasible to use transient electromagnetic in the geological lead prediction and the result coincided with the practical excavate situation, the average accuracy rate is up to 88.3% and the min resolution rate 1.2%.