doi:10.16186/j.cnki.1673-9787.2019080029

Received:2019/08/09

Revised:2019/09/14

Published:2021/03/15

Study on the time frequency domain signal characteristics and precursor earlywarning of acoustic emission in deep gneiss failure

SHAO Luhang1,2, KANG Zhiqiang1,2, XIN Dongfu1,2, ZHANG Chen1,2, YAO Xulong1,2

1.College of Mining Engineering， North China University of  Science and Technology， Tangshan  063210 ，Hebei， China;2.Hebei Province Key Laboratory of Mining Development and Safety Technigque， Tangshan  063210 ， Hebei， China

Abstract:Aiming at the frequent occurrences of rock sudden disasters in deep mining， the precursor characteristics of rock failure were revealed. The deep gneiss of Jinchang Sheet Metal Mine was taken as the research object， and the uniaxial compression acoustic emission test was used to study the relationship between the gneiss bearing process and the acoustic emission time -frequency domain characteristics， and the precursory characteristics of the acoustic emission and the time-frequency domain parameters before the rock failure and the coupling between above two were explored. The results showed that ： （1 ） Ringing count of acoustic emission time domain parameter showed obvious “ single peak“ type with sudden increase floating characteristic in the yield stage； ringing count rate， cumulative ringing count and energy rate， and accumulated energy presented “high value“ before the rock failure sudden increase phenomenon. （2 ） The main frequency of sound emission in rock failure was divided into five frequency bands. The ratio of low frequency band signal（0 〜40 kHz） increased first， then decreased， then increased and decreased； medium and low frequency band signals （40 〜 80 kHz ） were sporadic distribution and had no obvious features； the IF band signal（ 80 〜130 kHz） had the largest proportion in the whole process of rock failure， and it showed a steady change trend， showing a rapid increase before the rock failure； the middle and high frequency band signals （130 〜160 kHz ） occured only before the rock approached failure； the ratio of the high-band signal （ 160 〜200 kHz ） decreased first and then increased. （3 ） The ringing count before the critical failure， the “ sudden increase“ of the energy rate， and the “rapid increase" and " downward “ characteristics of the high -frequency signals at the same time and the “missing" characteristics of the low-frequency singles could be used as key precursor information for rock failure. Through analyzing the change of time-frequency domain characteristic parameters of acoustic emission， the rock failure precursor information could be judged and identified more accurately， which had important application value for mines development and safety warning of engineering construction.

Key words:gneiss;acoustic emission;time-frequency domain;precursor warning

 深部片麻岩破坏全过程声发射时频域信号特征及前兆预警研究_邵陆航.pdf