Research Article

Study on Multiparameter Precursory Information Identification of the Fracture of Yellow Sandstone

Table 4

Comprehensive index warning table.

Numbering of rock samplesAcoustic emission counting (N)b valueBody strain (%)Acoustic emission energyDissipative energy (kJmāˆ—āˆ’3)Average frequency (kHz)Peak frequency (kHz)Sample entropy

sz-1719.320.111.410.17.88.63.42.5
sz-1818.719.610.69.87.79.13.12.7
sz-2019.421.311.311.47.48.43.82.9
sz-2118.922.812.912.17.98.13.23.0