A tunnel advanced detection device and detection method based on optical fiber current sensor

Abstract

The invention discloses a bore-tunneling electrical ahead monitoring device based on an optical fiber current sensor, and a detection method thereof. The bore-tunneling electrical ahead monitoring device is composed of a constant current source, a voltmeter, a laser light source, the optical fiber current sensor and an anchor rod. A tunneling part of a tunnel boring machine (TBM) is supplied with a constant current I, a circle of an optical fiber winds around the rear part of a cutterhead and the rear part of a shield, the magnitude of current on each of the cutterhead, the shield and TBM rear guaranteeing equipment can be obtained by using the optical fiber current sensor, and voltage on the shield is measured for calculating apparent resistance of a geologic body, so as to judge water content and rock class of the geologic body. Compared with the traditional bore-tunneling electrical ahead monitoring method, the bore-tunneling electrical ahead monitoring device based on the optical fiber current sensor omits a great deal of pre-insulating operation.

Description

technical field [0001] The invention belongs to the technical field of tunnel engineering geological prospecting applications, and more specifically relates to a tunnel prospecting device based on an optical fiber current sensor and a detecting method thereof. Background technique [0002] In 2002, the German GEO company developed a tunnel ahead detection system (Bore-Tunneling Electrical Ahead Monitoring, BEAM) based on the focused current method. In order to improve the detection accuracy and directionality, a shielding current of the same phase is passed on the shield of the full-face tunnel boring machine (TBM) to make use of the characteristics of same-sex repulsion" Squeeze" the probe current to concentrate it more toward the front of the palm. However, before this method is applied, the cutter head and shield of the TBM need to be insulated. Due to the huge volume, complex structure, and huge force of the shield and cutter head, it is very difficult to insulate, and ...

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Problems solved by technology

However, before this method is applied, the cutter head and shield of the TBM need to be insulated. Due to the huge volume, complex structure, and huge force of the shield and cutter head, it is very difficult to insulate, and the geological conditions during the excavation process Complex and changeable, insulation may fail at any time

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