Abstract:

In view of the geological background of the tunnel face of an expressway near waterrich fault F4-3, in order to find out the situation of groundwater development in front of the tunnel face, transient electromagnetic method is used to carry out advanced geological prediction. Through multiline and multiazimuth detection methods and comprehensive analysis of the detection results of various position line, the development section and spatial distribution of groundwater in front of the tunnel face are predicted. The prediction results show that: 1) groundwater development in YK90+755~+811 section; 2) the waterrich position of YK90+755~+811 section is mainly located on the left and right sides of the excavation direction. At last, through the verification of advanced drilling, the location of the waterrich area of the transient electromagnetic detection is basically identical with the water outlet of advanced horizontal drilling, and the development stage of groundwater can be predicted accurately. The actual waterrich condition after excavation is basically consistent with the waterrich section of transient electromagnetic prediction and the spatial distribution of groundwater, and good prediction results are obtained.

Key words: highway tunnel, transient electromagnetic method, advanced geological prediction, waterrich section, spatial distribution of groundwater, multiazimuth detection