Abstract

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Title:: Infrasound Signal Characteristics of Rock Failure Under Different Stress States

Author(s):: XU Hong; SUN Cong-lu; REN Shi-cong; 1. Chongqing Engineering Research Center of Automatic Monitoring for Geological Hazards, Chongqing Institute of Geology and Mineral Resources, Chongqing 400042, China; 2. Chongqing Key Laboratory of Exogenic Mineralization and Mine Environment, Chongqing Institute of Geology and Mineral Resources, Chongqing 400042, China

Keywords:: rock failure; infrasound signal; time domain waveform; power spectral density function; time-frequency characteristic; compression; shear; tension

Abstract:: The test of rock failure under compression, shear and tension states was conducted in laboratory, and the infrasound signal during the destructive process was collected synchronously by the high sensitive collection system, and then the difference of infrasound signal under different stress states was studied. The results show that the infrasound signal appears mainly in elastic and plastic deformation stages under compression state, the peak frequency of infrasound signal is about 7 Hz, and the amplitude and frequency range keep rising before rock failure; the infrasound signal appears mainly in the stage of shear stress decreasing under shear state, the concentration of signal power is slightly less than that under compression state, and the peak frequency is about 8 Hz; the infrasound signal always associates with the whole loading process under tension state, and there are two bands of peak frequency, the lower band is close to compression test specimen, and the higher band is more than 3 Hz, the initiation and development of cracks are more rapid and orderly, and the frequency of infrasound signal keeps rising with the development of cracks. All the above characteristics provide a basis for the identification of infrasound signal and disaster prediction of rock under different stress states.