Three-dimensional analytical comprehensive solutions for acoustic emission/microseismic sources of unknown velocity system
DONG Longjun1，2，LI Xibing1，MA Ju1，TANG Lizhong1
(1. School of Resources and Safety Engineering，Central South University，Changsha，Hunan 410083，China；2. Jiaojia Gold Mine，Shandong Gold Group Co. Ltd.，Laizhou，Shandong 261441，China)
Abstract：The location accuracy of traditional methods based on the time difference is always influenced by the iterative method，the initial value and the pre-measured velocity. Solutions are not unique due to the square root calculations. In order to resolve the above two problems，the nonlinear location equations for the time difference of arrivals were simplified to linear equations and an analytical location method without the square root calculations was developed. A set of analytical solutions for AE / microseismic source location (ASS) were proposed for the unknown velocity systems where N = 6. Only the coordinates of the sensors and P-wave arrival times are required by the ASS method to accurately solve the source location parameters in real-time situations. The log-logistic distribution was used to determine the microseismic source locations. The blasting tests in the Dongguashan mine were used to verify the proposed analytical method for N≥6. Results show that the location accuracy of the proposed analytical solution is higher than the traditional method. The method highlights four outstanding advantages: no iterative solution; no pre-measured velocity; no initially evaluated source coordinates and no square root calculations.
2017, Vol. 36 
