System and method for forward-direction cross-hole radar transmission imaging advanced prediction of TBM construction tunnel

Abstract

The invention discloses a system and method for forward-direction cross-hole radar transmission imaging advanced prediction of a TBM construction tunnel. The system comprises a mechanical telescopic precession device installed in a TBM main body and at the back of a TBM cutterhead, and the mechanical telescopic precession device is formed by multi-level telescopic elements. The front end of the mechanical telescopic precession device is connected with a drill bit or the expandable multi-stage series connection radar antenna fixing sleeves by adopting a detachable structure, two drilled holes with the same depth are drilled in surrounding rock in front of the TBM main body under the control of the mechanical telescopic precession device, the sleeves are arranged, and a radar transmitting antenna and a radar receiving antenna are arranged in the two drilled holes respectively; the radar transmitting antenna and a radar receiving antenna are connected with a multichannel radar mainframe and a computer to perform cross-hole radar detection, and accordingly geological conditions in front of a tunneling surface are forecast rapidly and accurately.

Description

technical field [0001] The present invention relates to a cross-hole radar transmission imaging advance forecast system and method, in particular to a TBM construction tunnel forward cross-hole radar transmission imaging advance forecast system and method. Background technique [0002] In tunnel excavation construction, the main methods used are drilling and blasting construction and TBM construction. In recent years, the proportion of full-section tunnel boring machine (abbreviated as TBM) mechanical construction in tunnel construction has been increasing. The full-section tunnel boring machine uses rotary cutters to excavate, and at the same time breaks the surrounding rock in the hole and excavates to form the entire tunnel section. A new type of advanced tunnel construction machinery. Compared with drilling and blasting construction, TBM construction is mainly characterized by high degree of mechanization and fast speed, but poor adaptability to changes in geological co...

AI Technical Summary

Problems solved by technology

Compared with drilling and blasting construction, TBM construction is mainly characterized by high degree of mechanization and fast speed, but poor adaptability to changes in geological conditions. It often results in serious accidents where TBM machinery is stuck, buried or even scrapped. In order to ensure construction safety, TBM construction has stricter and more urgent requirements for geological advance prediction technology than drilling and blasting tunnel construction.

[0003] Due to the complexity and particularity of the TBM construction environment, it is very difficult to implement advanced geological prediction in TBM construction tunnels. The TBM mechanical system is a giant, occupying most of the space behind the tunnel excavation face, and the available detection space is narrow. The electromagnetic environment makes the advanced geological prediction method available in the drill and blast method unable to be used in the TBM environment

[0004] As far as the geological advance prediction technology in TBM construction tunnels is concerned, there are mainly the following two methods: ① One is to use the advanced drilling rig equipped with TBM machinery to perform horizontal drilling. This drilling rig can only reveal the geological conditions around the drilling hole. Geological bodies that do not intersect with the borehole cannot be ascertained, and cannot reflect the geological conditions in the entire range in front of the TBM working face. It is easy to miss bad geology, resulting in false positives, false negatives, and hidden dangers of disasters, and the economic cost and time cost of drilling are relatively high. high

②The other is to use the BEAM (Bore-Tunneling Electrical Ahead Monitoring) system developed in Germany. BEAM is a one-dimensional focused induced polarization method. The disadvantage of the BEAM method is that the installation of test equipment is complicated, the test time is long, and it seriously affects Construction progress; the second is that the BEAM method uses the curve of each measurement result and the tunnel mileage to infer the water content in front of the tunnel face, the detection distance is small, and tomography is not used for detection, so it is impossible to obtain the three-dimensional information of the geological body in front of the TBM face

In addition, judging from the application of the BEAM method in several tunnels in my country, the forecast results are not ideal and have not been popularized, and need to be improved and perfected

[0005] It can be seen that due to the narrow detection space, serious electromagnetic interference, and short available time in TBM construction tunnels, there is currently no very effective and practical advanced geological prediction technology and device.

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