Tunnel earthquake dual-source low-cost and high-efficiency observation system and high-resolution detection method

Abstract

The invention discloses a tunnel earthquake dual-source low-cost and efficient observation system and a high-resolution detection method, comprising a detector G1 and a detector G2, the detector G1 and the detector G2 are respectively installed in the detector holes on both sides of the tunnel bottom and correspond to each other; N shot points are evenly distributed on the tunnel inner wall on one side of the detector G1 along the length direction of the tunnel, and a blast hole is set at the shot point position close to the face of the tunnel, the N shot point positions are excited by a hammer source, and the blast hole position is excited by an explosive source, forming a unilateral observation system; or 2N shot points are evenly distributed on the tunnel inner wall on both sides of the detector G1 and the detector G2 along the length direction of the tunnel, and two shot point positions close to the face of the tunnel are both set with blast holes, the 2N shot point positions are excited by a hammer source, and the two blast hole positions are excited by an explosive source, forming a symmetrical observation system. The invention can save the cost of tunnel earthquake advance prediction and improve the accuracy of tunnel earthquake detection.

Description

Technical Field

[0001] The present invention relates to the technical field of tunnel earthquake detection and engineering survey, and in particular to a tunnel earthquake dual-source low-cost and high-efficiency observation system and a high-resolution detection method. Background Art

[0002] Advance geological prediction of tunnel earthquakes has become a necessary task for tunnel excavation and construction. Previous cases have shown that it can effectively reduce the risk of tunnel construction (Dickmann and Sander, 1996; Shi et al., 2014). The existing tunnel seismic geological prediction mainly includes 2-D tunnel seismic prediction (TSP) (Lin et al., 2006; Shi et al., 2014), integrated seismic imaging system (Borm et al., 2003), horizontal seismic profiling (HSP) (Inazaki et al., 1999), sonic soft ground probing (Kneib et al., 2000), tunnel seismic tomography (Tunnel seismic tomography) (Zhao et al., 2006), tunnel seismic-while drilling method (Petronio & Poletto 2002) and 3D True Reflection Tomography (True Reflection Tomography-3D TRT) (Shang et al., 2012). Explosives and sledgehammers are commonly used as seismic sources in the above methods. Due to the limitations of the tunnel environment, such as high-gas tunnels, sledgehammers are often used instead of explosives as seismic sources (Bellino et al., 2013). The 3-DTRT method also uses sledgehammers as seismic sources (Shang et al., 2012). The development of tunnel seismic source equipment is also gradually replacing sledgehammers, such as the automatic seismic source (Casey et al., 2002), electromagnetic impact seismic source (Richter et al., 2018), mechanical impact seismic source (Yordkayhun et al., 2012) and hydraulic impact seismic source (Liu et al., 2013).

[0003] When tunnels are excavated, an excavation damage zone is formed, and there is a significant difference in stress between the surrounding rock and the real surrounding rock in this area (Feng et al., 2016). Research on rock mechanics properties shows that the wave velocity and stress of the surrounding rock are closely related (Chai et al., 2019), and are linearly related at low stress (less than or equal to 60MPa) (Ma Chunde et al., 2018). There is a significant difference in the wave velocity between the surrounding rock in the excavation damage zone and the real surrounding rock. The explosive source explodes in a borehole with a depth of 1.5m, which can avoid the influence of the excavation damage zone. The sledgehammer source is excited on the surface of the tunnel wall and will be affected by the excavation damage zone. When explosives are used as the source, 24 boreholes with a depth of about 1.5m need to be drilled, which has high collection cost, long time consumption, and damage to the tunnel wall. When the sledgehammer is used as the source, it is directly excited on the tunnel wall without drilling, with low collection cost and high efficiency. In terms of collection cost and time consumption, compared with explosives, sledgehammers have obvious advantages. When it comes to stimulating energy, the sledgehammer has obvious shortcomings.

[0004] The resolution of reflection waves in tunnel seismic data is a key factor affecting the prediction accuracy. The wave field in tunnel seismic data is complex, with direct waves, surface waves, reflection waves, acoustic waves and other interference waves. When processing tunnel seismic data, a series of data processing methods are applied to enhance reflection waves and suppress surface waves (Lu et al., 2020). Due to the limited amount of tunnel seismic data, it is impossible to apply ground seismic data processing methods to improve the resolution of reflection waves. The methods that can be used to enhance the resolution of reflection waves in tunnel seismic data are very limited. The resolution of reflection waves in the original tunnel seismic data will directly affect the data processing results and ultimately affect the prediction accuracy.

[0005] The early tunnel advance prediction did not fully consider the impact of the tunnel excavation damage zone. Explosives are widely used in tunnel earthquake advance prediction. Although the acquisition cost is high, the prediction accuracy is generally recognized. The acquisition cost of sledgehammers is low, but there are still many doubts about the prediction accuracy. Combining the respective advantages of explosive sources and hammer sources in data acquisition and signal resolution, the present invention proposes a tunnel earthquake dual-source low-cost and efficient observation system and high-resolution detection method, aiming to save the cost of tunnel earthquake advance prediction and improve the accuracy of tunnel earthquake detection.

[0006] References

[0007] Bellino,A.,Garibaldi,L.,Godio,A.,2013.An automatic method for dataprocessing of seismic data in tunneling.

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[0010] Stavanger,Norway。

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[0012] Chai,J.F.,Wu,S.C.,Maria,T.B.,2019.Correlation between seismic wavevelocity,rock porosity,and maximumprincipal stress based on the laboratorytest data.Engineering Review,39(1),37-46。

[0013] Dickmann,T.,Sander,B.K.,1996.Drivage concurrent tunnel seismicprediction.Felsbau,14,406-411。

[0014] Feng,X.T.,Zhang,C.Q.,Qiu,S.L.,Zhou,H.,Jiang,Q.,Li,S.J.,2016.Dynamicdesign method for deep hard rocktunnels and its application.Journal of RockMechanics and Geotechnical Engineering,8,443-461。

[0015] Inazaki,T.,Isahai,H.,Kawamura,S.,Kuruhashi,T.,Hayashi,H.,1999.Stepwise application ofhorizontal seismic profiling for tunnelprediction ahead of the face.The LeadingEdge,18,1429-1431。

[0016] Kneib,G.,Kassel,A.&Lorenz,K.,2000.Automatic seismic prediction aheadof the tunnel bore machine.FirstBreak,18,295-302。

[0017] Lin,C.N.,Jiao,Y.Y.,Liu,Q.S.,2006.Site experiment for predictinghazardous geologicalformations ahead of tunnel face.Key EngineeringMaterials,326,461-464。

[0018] Liu,G.,Yu,C.G.,He,B.S.,Dong,Z.X.,2013.Design and experimental studyof mechanical downhole seismicsource.China Petroleum Machinery,41(11),17-20。

[0019] Lu,X.L.,Liao,X.,Wang,Y.,Wang,G.M.,Fu,Z.H.,Tai,H.M.,2020.The tunnelseismic advance predictionmethod with wide illumination and a high signal-to-noise ratio.Geophysical Prospecting,68(8),2444-2458。Petronio,L.&Poletto,F.,2002.Seismic-While-drilling by using tunnelboring-machine noise.Geophysics,67,1798-1809。

[0020] Richter,H.,Hock,S.,et al.,2018.Comparison of pneumatic impact andmagnetostrictive vibrator sources for nearsurface seismic imaging ingeotechnical environments.Journal of Applied Geophysics,159,173-185。

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[0022] Shi,S.S.,Li,S.C.,Li,L.P.,Zhou,Z.Q.,Wang,J.,2014.Advance optimizedclassification andapplication of surrounding rock based on fuzzy analytichierarchy process andTunnel Seismic Prediction.Automation in Construction,37,217-222。

[0023] Yordkayhun, S., Suwan, JN, 2012. A university-developed seismic source for shallow seismic surveys. Journal of Applied Geophysics, 82, 110-118.

[0024] Zhao, YG, Jiang, H., Zhao, XP, 2006. Tunnel seismic tomography method for geological prediction and its application. Applied Geophysics, 3(2), 69-74.

[0025] Ma Chunde, Guo Chunzhi, Fu Wei, Zhou Yanan. 2018. Research on the correspondence between rock wave velocity, stress and energy storage during loading and unloading within the elastic range

[0026] Research. Mining and Metallurgical Engineering. Vol. 38, No. 1. Summary of the invention

[0027] In view of at least one defect of the prior art, an object of the present invention is to provide a low-cost and efficient tunnel earthquake dual-source observation system, aiming to save the cost of advance prediction of tunnel earthquakes and improve the accuracy of tunnel earthquake detection.

[0028] In order to achieve the above object, the present invention adopts the following technical solution:

[0029] A low-cost and efficient tunnel earthquake dual-source observation system, the key of which is that it includes a geophone G1 and a geophone G2, the geophone G1 and the geophone G2 are respectively installed in the geophone holes on both sides of the tunnel bottom and correspond to each other; N shot points are evenly distributed on the tunnel inner wall on one side of the geophone G1 along the length direction of the tunnel, and a blast hole is set at the shot point position close to the tunnel face, the N shot point positions are excited by a hammer source, and the blast hole position is excited by an explosive source, forming a unilateral observation system;

[0030] Alternatively, 2N blast points are symmetrically distributed on the inner wall of the tunnel on both sides of the geophone G1 and the geophone G2 along the length direction of the tunnel, and blast holes are set at the two blast point positions close to the heading face. The 2N blast point positions are excited by hammer sources, and the two blast hole positions are excited by explosive sources, forming a symmetrical observation system.

[0031] The depth of the detector hole is 2m; N is 24; the hole spacing of the blast points is 1.5m; the horizontal offset distance between the blast point close to the tunnel bottom and the detector G1 or the detector G2 is 20m; each blast point is excited with a hammer source for more than 5 times; the depth of the blast hole is 1.5m; each blast hole is equipped with one explosive source.

[0032] The present invention proposes an observation system for dual-source joint acquisition combining explosive source and hammer source, including a single-side observation system for dual-source joint acquisition and a symmetrical observation system for dual-source joint acquisition. The joint acquisition method refers to using a low-cost sledgehammer or electromagnetic impact source as an excitation source, using a hammer source to excite at 24 or 48 blast points, and each blast point is excited more than 5 times. The blast point position near the face needs to be drilled with a 1.5m deep blast hole, and each blast hole is respectively equipped with an explosive source for one blast excitation.

[0033] If a single-side observation system is used at the tunnel site, at least 24 hammer source data and 1 explosive source data need to be collected. If a symmetrical observation system is used, at least 48 hammer source data and 2 explosive source data need to be collected. If the site conditions permit, the hammer source data should be repeated as much as possible at the same location to increase the amount of hammer source data.

[0034] The key to the high-resolution detection method of the tunnel earthquake dual-source low-cost and high-efficiency observation system is that: on the basis of dual-source data acquisition, a high-resolution detection method of dual-source data based on correlation calculation is proposed; the number of hammer strikes at the same shot point position is M times, and the recording time length of each hammer strike is t1, t2, ..., t M-1 ,t M The total recording time is The total observed field value at the hammer point x is R(x,T)=[r(x,t1),r(x,t2),....,r(x,t M )], i = 1, 2, ....., M; the seismic record of the explosive source is e(x, t1).

[0035] The key to the high-resolution detection method of the tunnel earthquake dual-source low-cost and high-efficiency observation system is that the time window length is set to t, the number of iterations in the correlation calculation is M times, and the specific calculation formula is:

[0036]

[0037] Where, l=1,2,.....,M, s=t×l,(t+1)×l,.....,(2t-1)×l,2×t×l; ψ a (x, t) is the function obtained by multiplying the observation record R(x, s) at the hammer point x by e(x, s), iterating M times and normalizing it.

[0038] Significant effect: The present invention provides a tunnel earthquake dual-source low-cost and high-efficiency observation system and a high-resolution detection method, which saves the cost of advance prediction of tunnel earthquakes and improves the accuracy of tunnel earthquake detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a single-side observation system for dual-source tunnel earthquakes;

[0040] Figure 2 It is a symmetrical observation system for dual-source tunnel earthquakes;

[0041] Figure 3 .(a) is a photo of the sledgehammer source data collection; (b) is a photo of the explosive source data recording;

[0042] Figure 4 is the original seismic record of the Y component: (a) uses explosives as the earthquake source; (b) to (f) use sledgehammers as the earthquake sources; symbol D represents direct wave, S represents surface wave, and A represents acoustic wave;

[0043] Figure 5 It is the spectrum analysis result from 0ms to 60ms;

[0044] Figure 6 .(a) to (e) are the processing results of sledgehammer source data;

[0045] Figure 7 .(a) Explosive source; (b) Cross-correlation of 5-shot records from sledgehammer source; (c) Cross-correlation of the 24th track from the explosive source with the record from the sledgehammer source;

[0046] Figure 8 Migration profile: (a) explosive source; (b) hammer source; (c) hammer source cross-correlation; (d) explosive source constrained hammer source cross-correlation;

[0047] Fig. 9 Excavation photos: (a) shale layer at a distance of 135m; (b) cave at a distance of 165m. DETAILED DESCRIPTION

[0048] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0049] like Figure 1-Figure 9 As shown, the present invention relates to a tunnel earthquake dual-source low-cost and efficient observation system and a high-resolution detection method, which mainly include: 1) design of a dual-source low-cost and efficient observation system; 2) a high-resolution processing method for dual-source seismic data.

[0050] The present invention provides a low-cost and efficient observation system and high-resolution detection method for tunnel earthquakes with dual seismic sources. The main advantages are as follows: 1) Compared with the existing tunnel earthquake observation system, the dual seismic source observation system only needs 4 drilling holes, directly saving the construction cost of ￥4400, and the data acquisition time is increased from 3 hours to 1 hour; 2) A data processing method based on correlation calculation is proposed, which uses a small amount of high-frequency explosive source signals as constraints to improve the resolution of a large number of low-frequency hammer source signals, suppresses surface wave interference, highlights the real reflected waves, and improves the accuracy of tunnel earthquake detection; 3) The influence of the first arrival picking error on the detection accuracy during the processing of hammer source data is eliminated, and the accuracy of tunnel earthquake detection is improved.

[0051] The present invention provides a tunnel earthquake dual-source low-cost and high-efficiency observation system and a high-resolution detection method, which mainly include:

[0052] (1) A dual-source low-cost and high-efficiency observation system was proposed. Combining the advantages of low acquisition cost and high efficiency of hammer source data acquisition by drilling holes randomly on the tunnel wall, a joint observation system combining explosive source and hammer source was designed. The invented observation system only requires 4 drilling holes, directly saving construction costs of ￥4400, and the data acquisition time is increased from 3 hours to 1 hour.

[0053] The dual-source low-cost and high-efficiency observation system is within the scope of patent protection.

[0054] (2) A high-resolution processing method for dual-source seismic data is proposed. In the seismic data collected by the proposed dual-source low-cost and efficient observation system, the reflection wave signal-to-noise ratio of the explosive source data is high, the surface wave interference is small but the number is small, and the reflection wave signal-to-noise ratio of the hammer source data is low, the surface wave interference is strong but the number is large. The proposed high-resolution data processing method uses a small amount of high-cost and high-frequency explosive source data to improve a large amount of low-cost and low-frequency hammer source data through relevant calculation constraints, and combines the respective advantages of dual-source data to achieve high-resolution tunnel seismic detection imaging.

[0055] The high-resolution processing method of dual-source seismic data falls within the scope of patent protection.

[0056] 1. Design of dual-source low-cost and high-efficiency observation system

[0057] The present invention proposes an observation system for dual-source joint acquisition, which combines explosive source and hammer source. Figure 1 The figure shows a single-side observation system with dual-source joint acquisition. Figure 2The figure shows a symmetrical observation system with dual-source joint acquisition. G1 and G2 are detectors with a hole depth of 2m. The single-side observation system has 24 shot points, and the symmetrical observation system has 48 shot points. The shot point hole spacing is 1.5m, and the horizontal offset distance between the shot point near the bottom of the tunnel and the detector is 20m. The joint acquisition method refers to using a low-cost sledgehammer or electromagnetic impact source as the excitation source, using a hammer source to excite at 24 shot points or 48 shot points, and each shot point is excited more than 5 times. The shot point position close to the tunnel face needs to be drilled with a 1.5m deep blast hole, and each blast hole is loaded with an explosive source for one shot excitation.

[0058] If the tunnel site adopts Figure 1 The single-side observation system shown in the figure needs to collect at least 24 hammer source data and 1 explosive source data. Figure 2 The symmetrical observation system shown in the figure needs to collect at least 48 hammer source data and 2 explosive source data. If the site conditions permit, the hammer source data can be repeated as much as possible at the same location to increase the amount of hammer source data.

[0059] The symmetrical observation system has more shot points and higher detection accuracy, but it is time-consuming and costly. Users can use a unilateral observation system or a symmetrical observation system according to their needs.

[0060] 2. High-resolution processing method of dual-source seismic data

[0061] The present invention proposes a dual-source data processing method based on correlation calculation. The number of hammer strikes at the same shot point is M, and the recording time length of each hammer strike is t1, t2, ..., t M-1 ,t M The total recording time is The total observed field value at the hammer point x is R(x,T)=[r(x,t1),r(x,t2),....,r(x,t M )], i = 1, 2, ....., M. The seismic record of the explosive source of the blast hole is e(x, t1).

[0062] If the set time window length is t, the number of iterations in the correlation calculation is M times, and the specific calculation formula is:

[0063]

[0064] Among them, l=1,2,...,M, s=t*l, (t+1)*l,..., (2t-1)*l, 2*t*l. ψ a (x, t) is the function obtained by multiplying the observation record R(x, s) at the hammer point x by e(x, s), iterating M times and normalizing it.

[0065] When there is no earthquake record e(x,s) of an explosive source at the hammer point x, it can be replaced by a hammer source.

[0066] Engineering Application

[0067] 1. Tunnel seismic data acquisition

[0068] The experimental area is located in a water diversion tunnel in Chongqing. The surrounding rock of the tunnel is mainly composed of the Tongzi and Honghuayuan formations of the Lower Ordovician. 1t+h ), the lithology is limestone, dolomite, biogenic limestone intercalated with shale, and the rock formation dip is 285°∠70°. According to the surrounding rock grade classification, it belongs to Class III. Tunnel fissure water is developed in the excavated area. According to the designed dual-source observation system ( Figure 1 ) Arrange the source points and receiver points. 24 source points and 2 receiver points. The TETSP-2 tunnel earthquake advance detection system is used to collect three parts of seismic data. The data sampling interval is 41.7μs, and the number of sampling points per channel is 8,192. The numerical simulation results prove the influence of the receiver hole depth on the wave field, so a fixed receiver hole depth is used in the tunnel field experiment. The receiver hole depth is 2.0m. The blast hole depth is 1.5m. The blast point spacing is 1.5m, and the offset distance is 20m. The source is 30g of explosives and a 24-pound sledgehammer. When the explosives are the source, the explosives are placed inside the blast hole. When the sledgehammer is the source, the tunnel wall surface is directly hammered at the blast hole position, and each point is hammered 5 times. Figure 3 In the figure, (a) is the sledgehammer source hammering the tunnel wall; (b) is the on-site waveform record collected by the explosive source.

[0069] 2. Data processing

[0070] like Figure 4 The original Y component data collected when the dynamite and sledgehammer are the earthquake sources. The symbol D is the direct wave, S is the surface wave, and A is the sound wave. In the data of the dynamite source, the direct wave (D) and the sound wave (A) are more obvious, and the surface wave interference is small. In the data of the sledgehammer source, the direct wave energy is low, the sound wave is almost submerged by the noise (A), and the surface wave interference is large. In the red box B area at the same position, the data of the dynamite source has less noise interference and a high signal-to-noise ratio ( Figure 4 (a)), while the data from the sledgehammer source has large noise interference and low signal-to-noise ratio ( Figure 4 ((b)-(f)). The statistical results of the signal-to-noise ratio in the time segment from 30ms to 60ms are shown in Table 1. The signal-to-noise ratio of the data from the explosive source is three to five times that of the sledgehammer source. The spectrum analysis results from 0ms to 60ms show that ( Figure 5 ), the data spectrum of the explosive source is between 1Hz and 1000Hz, and the data spectrum of the sledgehammer source is between 1Hz and 700Hz. In the later data processing, the spectrum analysis results are used as the parameters of the bandpass filter.

[0071] Table 1. Signal-to-noise ratio statistics of the Y component raw data.

[0072]

[0073] The above invention content is currently mainly used in the field of tunnel earthquake advance prediction.

[0074] right Figure 4 The seismic records from (b) to (f) are processed by a series of data processing methods such as channel equalization, automatic gain control, bandpass filtering, FK filtering, polarization filtering and predictive deconvolution to obtain the following: Figure 6 The seismic record shown. Waveforms with continuous events and strong energy are considered to be reflection waves from the leading direction. Figure 6 It is difficult to identify the reflected phase axis from the leading direction, and R1 and R2 are considered to be the most continuous reflected waves.

[0075] Figure 7 (a) Yes Figure 6 The data processing result of (a) shows that the reflected wave with strong energy and continuity can be picked up. R1, R2 and R3 indicate the reflected wave in the leading direction. Figure 7 (b) is to use Figure 6 (a) to (e) Waveform records obtained by cross-correlation calculation. Figure 7 (c) Figure 6 The 24th signal in (a) is a virtual source record. Figure 6 (a) to (e) Waveform records obtained by cross-correlation calculation. Figure 7 In (b), the continuity of R1, R2 and R3 is low, and the energy difference between adjacent traces is relatively large. Figure 7 In (c), the continuity of R1, R2 and R3 is good, and the waveform consistency is good.

[0076] 3. Migration imaging

[0077] from Figure 4 In (a), the first arrival travel time of the direct wave is picked up, and the slope of the direct wave is calculated by the least square curve fitting method as the true velocity of the surrounding rock. The estimated surrounding rock wave velocity is 6006m / s. The equal travel time surface migration algorithm is used to achieve the following Figure 8 The offset imaging section shown. Symbol I1 is the anomaly from mileage 82m to 100m, I2 is the anomaly from mileage 130m to 142m, I3 is the anomaly from mileage 160m to 172m. I4 is the anomaly from mileage 113m to 128m. I5 is the anomaly from mileage 95m to 111m, and I6 is the anomaly from mileage 145m to 156m. Figure 8 (a) is to use Figure 7 (a) The calculated migration profile shows three abnormal segments from I1 to I3. Figure 8 (b) is to use Figure 7(a) The calculated migration profile shows four abnormal segments from I1 to I4. Figure 8 (c) is the use of Figure 7 (b) The calculated offset profile shows four abnormal segments: I5, I2, I6 and I3. Figure 8 (d) is to use Figure 7 (c) The calculated offset profile shows three abnormal sections: I1, I2 and I3. Compared with other profiles, Figure 8 There are the most abnormal body interfaces in (b) and (c), and it is the most difficult to identify the real abnormal body interface. After the reflected wave R1 is implemented with offset imaging, the abnormal body I1 is obtained. Figure 8 (d) Figure 8 The energy of the anomaly I1 in (a) is higher mainly because Figure 7 (a) There are strong energy surface waves in R1 that have not been processed cleanly. After cross-correlation calculation, Figure 8 (c) R1 energy is relatively balanced, and the strong energy surface wave is suppressed. The explosive excitation energy is strong, and when the prediction distance exceeds 80m, there is still a strong energy abnormal body interface ( Figure 8 (a), I3). However, the energy of the hammer source is limited. When the prediction distance exceeds 80m, the energy of the abnormal body interface is low ( Figure 8 (d), I3).

[0078] Later excavation results showed that soft shale interlayers appeared in the abnormal body I2, such as Fig. 9 (a), while small caves and fracture zones appear in the anomaly I3, such as Fig. 9 (b) The excavation results are closest to the prediction conclusions obtained by the method proposed in this paper.

[0079] Finally, it should be noted that the above examples are only specific implementation examples of the present invention. Of course, those skilled in the art can make changes and modifications to the present invention. If these modifications and variations fall within the scope of the claims of the present invention and their equivalent technologies, they should be considered to be within the scope of protection of the present invention.

Claims

1. A high-resolution detection method for a tunnel earthquake dual-source low-cost and high-efficiency observation system, used for the tunnel earthquake dual-source low-cost and high-efficiency observation system, comprising a geophone G1 and a geophone G2, the geophone G1 and the geophone G2 are respectively installed in the geophone holes on both sides of the tunnel bottom and correspond to each other; N shot points are evenly distributed on the tunnel inner wall on one side of the geophone G1 along the length direction of the tunnel, and a blast hole is set at the shot point position close to the tunnel face, the N shot point positions are excited by a hammer source, and the blast hole position is excited by an explosive source, forming a unilateral observation system; or 2N shot points are symmetrically distributed on the tunnel inner wall on both sides of the geophone G1 and the geophone G2 along the length direction of the tunnel, and two shot point positions close to the tunnel face are both set with blast holes, the 2N shot point positions are excited by a hammer source, and the two blast hole positions are excited by an explosive source, forming a symmetrical observation system; Features: On the basis of dual-source data acquisition, a high-resolution detection method of dual-source data based on correlation calculation is proposed; In the seismic data collected by the proposed dual-source low-cost and high-efficiency observation system, the reflected wave signal-to-noise ratio of the explosive source data is high, the surface wave interference is small but the number is small, and the reflected wave signal-to-noise ratio of the hammer source data is low, the surface wave interference is strong but the number is large; the proposed high-resolution data processing method is to use a small amount of high-cost and high-frequency explosive source data to improve a large amount of low-cost and low-frequency hammer source data through relevant calculation constraints, and combine the respective advantages of the dual-source data to achieve high-resolution tunnel seismic detection imaging; The number of hammer strikes at the same blast point is M, and the recording time length of each hammer strike is t1, t2, ..., t M-1 ,t M The total recording time is The total observed field value at the hammer point x is R(x,T)=[r(x,t1),r(x,t2),....,r(x,t M )], i = 1, 2, ....., M; the earthquake record of the explosive source is e (x, t1); The set time window length is t, the number of iterations in the relevant calculation is M times, and the specific calculation formula is: Where, l=1,2,.....,M, s=t×l,(t+1)×l,.....,(2t-1)×l,2×t×l; ψ a (x, t) is the function obtained by multiplying the observation record R(x, s) at the hammer point x by e(x, s), iterating M times and normalizing it.

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