A new location method of microseismic source without pre-measuring speed

摘要

In recent decade, geophysical methods, such as microseismic monitoring, geotomography, and in-seam seismic techniques, have shown an increased significance in rock physical mechanics and mining engineering.Especially the developments of seismic monitoring bring hope to predict the rock burst and seismic hazards, where potential location determination of hypocenter is the key technology.In previous study, the location techniques all need two hypotheses: 1) The propagation speed can be measured accurately;2) Seismic wave propagates in homogeneous, isotropic geological structures.While in practical applications, heterogeneous geological structure makes the medium (what the seismic wave propagation) shows anisotropic feature instead of isotropic.Meanwhile measuring the propagation speed accurately is very difficult.In order to solve these two problems, localization method of microseismic source based on the genetic algorithm without pre-measuring speed is proposed.This method assumes that the seismic wave propagates in the direction of a spindle, and the propagation speed is the fastest along the spindle direction.The equations are established in which the source position, propagation speed and spindle orientation are variables.Finally, the equations were solved through genetic algorithm.The comparison between the predict results by our method and the experimental data measured in DongGua Copper showed that the proposed method can predict the source location more accurately, and with a good prospect.