Research On The Method Of Microseismic Source Location Based On High-dimensional Search Algorithm

Microseismic monitoring technology refers to a kind of real-time monitoring technology that uses the microseismic signal generated by rock mass to study the situation of rock mass fracture and evaluate the safety and stability of rock engineering when rock mass breaks.This technology has been widely used in various geotechnical engineering.The location of microseismic source is the core and foundation of microseismic monitoring technology.In this paper,the processing of microseismic signal and the location of microseismic source are studied.The three-dimensional model of microseismic environment is established by COMSOL multiphysics software,and the simulation is carried out.The influence of excitation conditions and sensor layout on the location is analyzed.The k-nearest-neighbor high-dimensional search algorithm is applied to the location of microseismic events.The specific research is as follows:(1)The occurrence principle,characteristics and basic parameters of microseisms are described.According to the characteristics of microseismic signal,the processing of microseismic signal is discussed.The time acquisition is carried out by STA / LTA,the noise reduction filter is carried out based on the variational mode decomposition and independent component analysis,and the feature extraction and dimension reduction method are carried out by T through the principal component analysis logarithm data when studying the high-dimensional microseismic data.(2)The three-dimensional model of microseismic environment is established by the finite element software COMSOL multiphysics.The excitation signal is applied to simulate the occurrence of microseisms.The acceleration signal is detected by the probe to simulate the wave signal reception.The influence of excitation change and sensor layout on microseismic positioning is analyzed.The results show that the waveform received by the sensor is directly proportional to the magnitude of the excitation.The increase of the amplitude of the excitation will cause the amplitude of the waveform to increase,but will not affect the shape of the waveform.The layout of sensors has a great impact on the accuracy of microseismic location.The closer to the center of the sensor network,the more accurate the microseismic event location will be.Through comparison,it is found that Newton iterative method is more susceptible to the impact of sensor layout than high-dimensional search algorithm.(3)In this paper,the classical positioning methods,Newton iterative positioning method and simplex positioning method,which are widely used in the field of microseismic research at present,are discussed.Therefore,using a high-dimensional search algorithm,through the establishment of a database,search in the database to get the positioning results,to avoid the problem of inaccurate positioning caused by the complexity of the wave velocity model.(4)The experiment platform is built,the cement block is used as the sample,the micro seismic waveform is collected by the way of percussion,and the location is carried out by the experimental data,which verifies the feasibility and superiority of the high-dimensional search algorithm.(5)The high-dimensional search algorithm is used to verify the location of the actual data of a coal mine in Inner Mongolia.The results show that the method has high positioning accuracy,and can meet the requirements of microseismic positioning in accuracy and efficiency.