34 meters for frontal detection.

By adopting some technology of advanced detection,adding temporary invert,sleeve valve pipe and lock foot bolts,the construction of the tunnel is completed safely and successfully.

Sector detection technology was used to enhance the explanation accuracy of mine transient electromagnetic method in advanced detection instead of conventional survey.

The results show that advanced detection apparatus DTC-150 can detect geologic formation in front of the mine excavation 100 m away,and can more accurately detect faults,rock fissures,rock broken cinctures and water-rich situation,and the collection velocity can be used to classify the wall rock.

The portable mine detector,which is used to make advance detection of the front small structure of the mining faces by utilizing the diffracted wave,has become an effective auxiliary tool for the forecasting in the tunnelling.

The advantages of Rayleigh wave for water-bearing fault belt pre-detection in the process of tunnel construction by analyzing an example are introduced on the basis of expounding Rayleigh wave detection basic theory,and a kind of simple,efficient new technique for pre-detecting water-bearing fault belt in the process of tunnel construction is displayed.

With the increasing of tunnel engineering in our country, they become into deeper, bigger, longer, the engineering geological and hydrological geology problem being more complex, the theory study and practice on the ahead detecting and predicting are becoming more significant.