AUTOMATIC DETECTION OF FRONT ABNORMAL MATTER IN TUNNEL CONSTRUCTION METHOD

摘要

PURPOSE:To automatically detect abnormal matter by modeling the waveform of the receiving signal of estimable abnormal matter using a sonic wave to perform the pattern matching with the waveform of an actual receiving signal. CONSTITUTION:One transmitter and a plurality of receivers 14 are attached to the cutter surface of a tunnel excavator 12 and, at each time when the excavator 12 advances over a proper distance, the excavation distance is observed to obtain distance data in relation to front abnormal matter corresponding to the number of times of observation. A contrete distance is calculated by multiplying the half of the time from the transmission of a sonic wave to the reception of the reflected wave from the abnormal matter by the sonic wave in soil. Then, the modeling of the reflected wave from the abnormal matter is performed. A transmitter is a converter converting an electric signal to a sound pressure signal and the receivers are converters converting the sound pressure signal to the electric signal and both of them have ultrasonic vibrators and the input and output relation of them is expressed by a secondary attenuation vibration model. This modeled receiving waveform and an actually measured receiving waveform are subjected to pattern matching to detect the abnormal matter.