Tunnel Drill Jambo Active Source Seismic Wave Field Characteristics And Effective Wave Identification Method And Application

The extremely complex and harsh construction environment of the Sichuan-Tibet railway tunnel makes the construction risk very high.Under the circumstances,the traditional manpower-based construction method will cause the construction progress to be slow,the efficiency to be reduced,and even impossible to construct.Therefore,the Sichuan-Tibet Railway drilling and blasting tunnel will use drill jambo to construction on a large scale.Based on this background,research on an advanced geological prediction method that can match the efficiency of mechanized construction is of great significance to promote the construction of the Sichuan-Tibet Railway with"high starting point,high standard,and high quality".A new tunnel seismic advanced geological prediction technology using drilling jumbo bit to excite the seismic source was put forward in this paper.Compared with the traditional technology,this new technology can achieve synchronization during the drilling process of drill jambo,greatly reducing the impact of the advanced geological prediction method on the tunnel construction period,increasing the construction efficiency,reducing the manpower input on the Sichuan-Tibet railway,and improving the tunnel construction safety.At present,the seismic while drilling technology as the basis for the research of this method are relatively mature for cone bit in the drilling field.However,the seismic wave field of rock-breaking seismic source of drill jambo is more complicated,and it has the characteristics of complex source excitation methods and mixing of multi-source wave fields.There is no precedent for the application of seismic while drilling technology to drill jambo.Therefore,it is urgent to carry out research on the characteristics of seismic wave field and effective signal identification of rock-breaking seismic sources.Based on the actual projects of the Xingshan Tunnel of the Zhengwan High-speed Railway and the Xiwuling Tunnel of the Changjing-Huangzhou High-speed Railway,this paper has carried out systematic research on the characteristics of rock-breaking seismic source seismic wave field and effective signal identification by theoretical research,field test,numerical simulation,engineering application and other research methods.The main research work and results are as follows:(1)Reveals the characteristics of the seismic wave field and the propagation law of the rock-breaking source of drill jambo.In this paper,a large amount of rock-breaking source data is collected on site,and the rock-breaking seismic signal characteristics are studied;The source signal function is simulated,and the forward simulation of drill jambo’s single-arm and three-arm rock-breaking source is carried out.The research has obtained the characteristics and propagation laws of the seismic wave field of the single-arm and the three-arm rock-breaking source in the typical unfavorable geological body model.It provides a theoretical direction and data basis for the subsequent study of seismic record reconstruction and the separation method of mixed rock-breaking source seismic data.(2)Formed a set of seismic record reconstruction methods suitable for drill jambo.Aiming at the problem of seismic wave field aliasing caused by continuous impact and rotary cutting of the drilling jumbo bit and seismic records cannot identify effective signals after cross-correlation,the research focused on the research on the extraction of the single impact signal of the drilling jumbo bit and the reconstruction of seismic records.The paper took the seismic source generated by the single-arm drilling of drilling jumbo as the research object.A data processing method based on least-squares deconvolution for extracting a single pulse signal of the drill bit from the continuous pilot signal is proposed,and filter out periodic interference components,And through the cross-correlation of the seismic data after deconvolution,the reconstructed seismic record similar to that under pulsed source excitation is obtained.The research has realized the identification of the effective signal of drilling jumbo’s single-arm rock-breaking source seismic record.(3)Established seismic data separation method combining ICA and cross-correlation for mixed rock breaking source of drilling jumbo.According to the independent characteristics of the three-arm rock-breaking seismic sources,a mixed seismic source model of drilling jumbo is constructed,and the independent component analysis method is introduced;Aiming at the problem of the distortion of the ICA separation result of the mixed source signal with the low signal-to-noise ratio,a separation scheme of wavelet threshold de-noising first,and ICA separation second is established;After the cross-correlation processing of the separated signal and the mixed seismic record,the single-arm rock-breaking source seismic record is obtained.Combined with the single-arm seismic record reconstruction method,The research has realized the separation and reconstruction of the seismic record of drilling jumbo mixed rock-breaking source.The research results have been applied in the actual project of the Xiwuling Tunnel of the Changjing-Huangzhou High-speed Railway.The prediction results are basically consistent with the actual excavation,which verifies the effectiveness of the prediction method.