Signal Denoising And Pickup Method Based On Microseismic Response Characteristics Of Water Inrush And Engineering Application

China has become the country with the largest scale,quantity and difficulty in traffic tunnel construction in the world.In the process of tunnel construction,it is easy to cause sudden water inrush disaster,which causes heavy casualties,serious economic losses and bad social impact.Therefore,real-time monitoring of tunnels is an important means to reduce sudden water inrush.As a remote real-time monitoring method,microseismic monitoring technology can provide precursor warning information for disasters through the difference of microseismic event responses in the evolution process of sudden water inrush disasters.Therefore,the research on microseismic monitoring technology is of great significance to realize the active prevention and control of sudden water inrush.Based on the characteristics of microseismic response of sudden water inrush disaster,this paper aims at optimizing the technical parameters of optical fiber microseismic monitoring system and realizing accurate and rapid analysis of water inrush microseismic signals.Through literature investigation,theoretical analysis,numerical simulation,indoor test and field test,three aspects of research are carried out:in the aspect of optical fiber microseismic monitoring system for tunnel water inrush disaster,the optimal design parameters of optical fiber microseismic monitoring system for tunnel water inrush disaster are put forward,and applicable microseismic monitoring equipment is developed;In the aspect of water inrush microseismic signal noise reduction,a composite multi-scale permutation entropy and complementary integration empirical mode decomposition method is proposed,which improves the ability of water inrush microseismic signal identification and extraction;In the aspect of picking up water inrush microseismic signals,a method of picking up water inrush microseismic signals by fusion of high-order statistics kurtosis and red pool information criterion is established,which improves the accuracy of picking up water inrush microseismic signals.(1)In view of the technical bottleneck of water inrush microseismic signal monitoring and effective analysis,as well as the equipment limitations of the traditional electrical microseismic monitoring system,such as waterproofness and narrow sensor response frequency band,the microseismic response characteristics of two types of water inrush disasters,i.e.,progressive failure of fractured rock mass and seepage instability of filling medium,were revealed through relevant research at home and abroad.Based on the frequency range of the two types of water inrush disasters,an optical fiber microseismic monitoring system for tunnel water inrush was developed.(2)to solve the problem that effective signals of water inrush microseismic are difficult to separate in strong noise environment,based on the microseismic response characteristics of two types of water inrush disasters,a denoising method of water inrush microseismic signals based on composite multi-scale permutation entropy-complementary integrated empirical mode decomposition is proposed,which improves the recognition ability of water inrush microseismic signals,solves the interference problem of auxiliary white noise and environmental noise on effective signals in CEEMD method,and realizes accurate recognition of effective signals of water inrush disasters.(3)Aiming at the problems of large error and low efficiency in picking up the first arrival of conventional microseismic signals,a fusion time picking method based on kurtosis of high-order statistics and red pool information criterion is proposed.By comparing the results of four methods to the microseismic signals with high and low signal-to-noise ratio,as well as the time-pickup test of explosion vibration with equal channel spacing,it is verified that the K-AIC time-pickup method proposed in this paper has less dependence on the size of sliding time window,stronger anti-noise ability,and better robustness and accuracy.To sum up,through the research and development of optical fiber microseismic monitoring system for tunnel water inrush disaster and the proposed method of noise reduction and pick-up of water inrush microseismic signals,this paper breaks through the monitoring applicability bottleneck of traditional equipment and solves the problem that water inrush signals are difficult to identify effectively and pick up accurately.