A model of electromagnetic emissions from multicracking extension during rock fracture

All theories of electromagnetic emission (EM) related to rock crack were ba sed on the model of the single-crack extension in the past. Experiments ind icted that the simultaneous extension of multi-crack exists during rock cra ck. Thus there is electromagnetic emission not only in single-crack but als o in multi-crack extension in crack of rocks. We propose the model of elect romagnetic emission from multi-crack simultaneous extension based on the ex perimental phenomenon. Using this model, the electromagnetic field of EM ha s been calculated in the simple condition. Our result show that the emissio n and property of EM is different from single crack. Its amplitude is N tim es that of latter and its emission direction is stronger. In comparison wit h the experimental recorded value,we find the maximal value of EM calculate d by the model almost coincide with it.