岩石の一軸圧縮破壊の過程における微震音の発生特性

抄録

Rocks in instability under stress are prone to produce micro-seismic noise, and it is considered that that has something to do with destruction of rocks.
In order to find a suitable method for foreseeing roof falls in tunnel construction works or slope failures in excavation works by detection of the micro-seismic noise, the necessary studies of fundamental facts are being made in the laboratory.
The present paper describes the results obtained from the experiments of the micro-seismic noise during destruction of rock samples under the laboratory condition.
The main results are summarized as follows.
The relationship between the occurrence of micro-seismic noise and the load depends on the properties of the rock. The frequency distribution of number of the micro-seismic noise with respect to the energy possesses a statistical regularity, and it is expressed by the following equation:
n(e)=k·e^-m
where e is the energy of the micro-seismic noise, n(e) is the number of the micro-seismic noise having energy e, and k and m are constants.
In the above equation, the value of m has relation to the modulus of elasticity of the rock and depends on the deformation condition during the process of destruction.
It is suggested that the value of m is an important index for predicting rock failures.