Research And Implementation Of The Tunnel Water Inrush Advanced Detector Based On The Introduced Polarization Method

As the development of economy, more and more deep seated long tunnels are being constructed, so water inrush and other geological disasters are also increasing during the tunnel construction. These disasters not only delay the schedule, resulting in huge direct and indirect economic losses, but also may cause casualties. Therefore, finding an effective method to predict Karst Geology in front of the tunnel and making the equipment based on this method have become increasingly important.Two-current IP method predicts water bearing structure in front of the tunnel, based on the effect of water bearing structure upon induced polarization. Using this method, we can predict the presence of moisture structure, the location, and even predict the water content. Because of the instrument measurement accuracy and other reasons, this method is mostly limited to theoretical studies before, rarely applied to the actual situation.This paper is aimed to design and implement the tunnel water inrush advanced detector based on this method and to make thorough research and optimization to several key links. First of all, the induced polarization effect and the mechanism of Two-current IP method are introduced to analyze the effectiveness of this detector system theoretically; Second, introduce the design, the structure and their functions of the detector system based on this method, so we can grasp design ideas of the whole system in general; from the two levels of hardware design and software design, make thorough research to acquisition of signal, delivery, access and purification and other key links, and propose optimal design techniques, such as two-stage 50Hz notch filtering, self-adapting gain amplifier, all interrupt delivery mechanism of data stream, access to data file from FAT filesystem in CF card, two-stage zeroing based on PID algorithm, wavelet transform de-noising technique and so on, to improve system stability, accuracy, real-time and use flexibility, satisfying the research and practical requirements; Finally, put the instrumentation based on the design to model test and field test, analyze the measuring result, and then prove the validity of the instrument and the method from practice.