Extraction And Analysis Of Microseismic Weak Signal In Jinchuan Nickel

At present, the issue of mine safety is obvious, strengthening the roadway support and improve safety monitoring system are necessary means to ensure efficient production and personnel safety of life and property.Micro seismic monitoring technology is to extract the information of rock fracture deformation by screening, analyzing and locating the monitored signal and providing scientific support for the design and optimization of supporting scheme.The extraction and analysis of micro seismic signal based on time-frequency analysis is the key point that affects the accuracy of micro seismic monitoring, and is also the key point of this paper.First, this paper systematically introduces the principle of micro seismic monitoring technology and the common methods of time-frequency analysis.The numerical simulation based on MATLAB platform is used to show the advantage of S transform in dealing with non-stationary signals,and the correctness of this method is verified by comparing with Siroseis software developed by CSIRO.Finally, the S-Transform is chosen to analyze the micro seismic signal of mine.Secondly, by using ST to extract the signal characteristics of frequency,energy,duration,the monitored signal can be grouped into six classes,rock fracture signal, knocking signal, blasting signal, electric pulse signal,drilling signal, vehicle signal.The K-means is introduced to improve efficiency and accuracy of mine microseismic signal classification,the results show that the classification accuracy of rock fracture signal,burst signal and knocking signal are 100%, 79.59% and 76.19%.It puts forward a new idea for the automatic identification of mine microseismic signals.Finally, the results of the convergence monitoring and micro seismicmonitoring are analyzed in this peper,both conclusions are shown that the surrounding rock deformation is very intense in the early stage of excavation,and is tended to be stable at about 25 days after excavation.Based on the conclusion,25-30 days after the excavation is suggested as the best time point to do the secondary support,so that can make full use of the bearing capacity of surrounding rock.