Seismic wave continuous detection method and system for double-line TBM construction tunnel

Abstract

The invention relates to the technical field of tunnel engineering and engineering geophysical prospecting, and discloses a seismic wave continuous detection method and system for a double-line TBM construction tunnel, and the method comprises the steps: laying an observation system, and carrying out the data collection through employing a fixed receiving and transmitting distance; data continuous acquisition: performing data acquisition during heading of a previous tunnel, performing continuous data acquisition along with heading of a cutterhead, and continuously acquiring multi-source multi-wave-field data not lower than a set group number in a single test; refracted wave data are processed, and the continuous speed profile of the to-be-excavated area of the following tunnel is obtained according to the obtained speed distribution information; interpreting refracted wave data, and realizing geological interpretation of geophysical prospecting data according to the obtained continuous transverse velocity profile of the to-be-excavated area of the following tunnel in combination with geological information and structural distribution of the excavated hole body section of the preceding tunnel; and seismic multi-wave-field multi-view-field comprehensive detection is carried out to obtain the unfavorable geological distribution condition vertical to the line direction. According to the invention, multi-wave-field, multi-mode and multi-view comprehensive detection of the seismic wave method can be realized.

Description

Technical Field

[0001] The invention relates to the technical field of tunnel engineering and engineering geophysical exploration, and in particular to a method and system for continuous seismic wave detection in a double-line TBM construction tunnel. Background Art

[0002] During tunnel construction, accurate advance geological forecasts of the geological conditions and possible geological disasters ahead of the heading face play a vital role in the normal construction and smooth penetration of the tunnel. The existing advance detection method suitable for TBM construction tunnels is mainly based on the seismic wave reflection method, which has achieved certain results in detecting structures and structures based on physical properties such as density and velocity. However, the seismic wave reflection method is limited by the high-mechanical construction environment of TBM, and its detection efficiency and accuracy still have much room for improvement. Summary of the invention

[0003] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a method for continuous detection of seismic waves in a double-line TBM tunnel construction, comprising the following steps:

[0004] Step 1: Set up the observation system, using 8-channel seismic detection equipment, of which 6 channels are used for data acquisition and 2 channels are used to collect TBM body self-seismic signals; the trigger detector is fixed to the TBM cutterhead to record the self-seismic signals; the receiving detector is arranged in a straight line on the same side wall and coupled with the side wall surrounding rock through hydraulic struts; the offset distance is selected according to the distance between the preceding tunnel and the succeeding tunnel, and the fixed transmitting and receiving distance is used for data acquisition;

[0005] Step 2: Continuous data collection: data collection is performed during the advance tunnel excavation, and continuous data collection is performed as the cutterhead excavates. A single test continuously collects not less than a set number of multi-source multi-wavefield data, wherein the multi-source multi-wavefield data includes a fuselage self-seismic signal, a direct wave signal, a reflected wave signal, and a refracted wave signal;

[0006] Step 3: Processing the refraction wave data: extracting the refraction wave signal from the collected multi-source multi-wavefield data, synthesizing the collected multi-source multi-wavefield data of not less than the set number into single-shot multi-wavefield data, and obtaining the effective refraction wave signal from the single-shot multi-wavefield data, performing inversion, and obtaining the velocity distribution information within the set range of the preceding tunnel and the succeeding tunnel, and obtaining the continuous velocity profile of the to-be-excavated area of ​​the succeeding tunnel according to the obtained velocity distribution information;

[0007] Step 4: Interpretation of refraction wave data: Based on the continuous transverse velocity profile of the area to be excavated in the subsequent tunnel, combined with the geological information and structural distribution of the excavated section of the preceding tunnel, the geological interpretation of the geophysical data is realized;

[0008] Step 5: Comprehensive seismic multi-wave field and multi-view detection is based on the detection results obtained from the previous tunnel side wall detection, and the velocity profile obtained from the lateral detection is used as the initial model. The forward seismic wave reflection method is used for advance detection at the heading of the subsequent tunnel to obtain the distribution of adverse geological conditions perpendicular to the line direction.

[0009] Furthermore, the method of coupling the detector to the structure includes:

[0010] S11, the trigger detector is fixed near the cutterhead in the shield body. A wide-band low-sensitivity detector is selected to reduce false triggering due to mechanical noise. The trigger detector is mainly used for the collection of excitation and self-seismic signals during TBM excavation and the trigger system of the forecasting equipment. This part of the signal needs to be filtered out from the collected signal during data processing later.

[0011] S12, the receiving detector needs to be fixed on the TBM body and coupled with the surrounding rock by means of a hydraulic strut. The detector is installed on the top of the strut, and the strut is remotely controlled by the host computer. When the test starts, the strut is automatically pushed onto the surrounding rock for data collection. After the data collection is completed, the strut is automatically retracted.

[0012] Furthermore, the selection of the offset distance according to the distance between the preceding tunnel and the succeeding tunnel includes:

[0013] The offset distance is determined by combining the distance between the preceding tunnel and the succeeding tunnel. According to the principle of refraction wave exploration, the detection depth h and the offset distance X1 satisfy the formula:

[0014] X1=2htan(θ c )

[0015] where θ c Critical Angle V1 is the wave velocity of the upper layer, V2 is the wave velocity of the lower layer medium, and the detection depth h = h1 + h2, where h1 represents the distance between the double-line tunnels, and h2 represents the cross-sectional width of the rear tunnel. This is used to calculate the offset distance X1 and the maximum offset distance X2. max Take 5-7 times the detection depth h, that is, 5h=<X max <=7h.

[0016] Furthermore, the specific steps for implementing the coherent stacking of TBM multi-source multi-wavefield data in the step (S3) are:

[0017] S31, signal filtering: The TBM multi-source seismic wave field data is filtered through spectrum analysis, correlation analysis and other processing methods. The frequency band range of effective signals, interference, etc. can be obtained through spectrum analysis. For the TBM rock-breaking source refraction wave, the effective spectrum range is the medium and low frequency band. Through filtering processing, the interference waves of the original seismic record can be effectively removed to highlight the effective signal.

[0018] S32, cross-correlation processing: By introducing the cross-correlation function to measure the similarity between TBM seismic wave data, one set of data f(t) is placed relative to another set of data g(t) in different amounts, and the corresponding values ​​in the two sets are multiplied and the product is obtained to obtain the cross-correlation value h(t):

[0019]

[0020] In the formula is the cross-correlation operator, and * is the convolution operator.

[0021] Furthermore, the seismic multi-wavefield multi-view comprehensive detection is based on the detection results obtained by the previous tunnel side wall detection, and the velocity profile obtained by the lateral detection is used as the initial model. The forward seismic wave reflection method is used for advance detection of the tunnel face to obtain the distribution of adverse geology perpendicular to the line direction, including:

[0022] S51: On-site implementation of seismic refraction wave detection of the side wall of the leading tunnel, and collection of transverse refraction wave data of the tunnel to be excavated; on-site implementation of seismic reflection wave detection of the working face of the trailing tunnel, and collection of longitudinal reflection wave data of the tunnel to be excavated;

[0023] S52, processing the data of the transverse detection refraction wave method to obtain the transverse velocity profile of the tunnel to be excavated, and extracting and digitizing the geometry of the subsequent tunnel section of the velocity profile;

[0024] S53, based on the transverse detection velocity profile, construct the initial velocity model, carry out longitudinal detection (seismic wave reflection method) data processing and inversion work, and obtain the comprehensive interpretation results of the subsequent tunnel

[0025] A system for continuous seismic wave detection in a double-line TBM tunnel construction, using the method for continuous seismic wave detection in a double-line TBM tunnel construction, comprising an 8-channel seismic detection device, a trigger detector, a receiving detector and a host computer module;

[0026] The 8-channel earthquake detection equipment, trigger detector and receiving detector are respectively connected to the host computer module.

[0027] The beneficial effects of the present invention are as follows: (1) The present invention innovates the observation method of geological detection in TBM tunnel construction. Through the working mode of the cutterhead of the leading tunnel and the receiving working mode of the side wall, it has the following advantages over the prior art: continuous detection is carried out along with the excavation of the leading tunnel, and the detection length is not limited by the excavation of the subsequent tunnel, so that a continuous velocity profile of the subsequent tunnel to be excavated can be formed.

[0028] (2) The present invention increases the breadth and latitude of tunnel advance detection. By introducing the detection method of seismic refraction wave method, the detection target of lateral structure is achieved. Compared with the existing technology, it has the advantages of rich detection information and easy extraction of effective information. It overcomes the problem that the traditional seismic wave method is difficult to detect hidden structures along the tunnel axis.

[0029] (3) The present invention improves the accuracy of geological advance detection in TBM scenarios. By comprehensively interpreting the geological information revealed in the advance tunnel, the detection results of the refraction wave method in the advance tunnel, and the detection results of the seismic reflection wave method in the subsequent tunnel, the present invention realizes a comprehensive detection technology with multiple wave fields, multiple modes, and multiple fields of view. At the same time, through the convenient arrangement system mounted on the TBM body, the impact of the environment on the layout of the observation system is reduced, and the interference and multiple solutions caused by different sources are reduced. The on-site test is fast, simple, and efficient, which improves the accuracy of poor geological detection in the subsequent tunnel. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A schematic diagram of a process for continuous seismic wave detection in a double-line TBM tunnel construction method;

[0031] Figure 2 It is a schematic diagram of the specific structure of the hydraulic support rod system;

[0032] Figure 3 This is a schematic diagram of the source conversion principle;

[0033] Figure 4 Schematic diagram of comprehensive interpretation of lateral detection. DETAILED DESCRIPTION

[0034] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings, but the protection scope of the present invention is not limited to the following.

[0035] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.

[0036] like Figure 1 As shown, a method for continuous seismic wave detection of a double-line TBM tunnel construction includes the following steps:

[0037] Step 1: Set up the observation system, using 8-channel seismic detection equipment, of which 6 channels are used for data acquisition and 2 channels are used to collect TBM body self-seismic signals; the trigger detector is fixed to the TBM cutterhead to record the self-seismic signals; the receiving detector is arranged in a straight line on the same side wall and coupled with the side wall surrounding rock through hydraulic struts; the offset distance is selected according to the distance between the preceding tunnel and the succeeding tunnel, and the fixed transmitting and receiving distance is used for data acquisition;

[0038] Step 2: Continuous data collection: data collection is performed during the advance tunnel excavation, and continuous data collection is performed as the cutterhead excavates. A single test continuously collects not less than a set number of multi-source multi-wavefield data, wherein the multi-source multi-wavefield data includes a fuselage self-seismic signal, a direct wave signal, a reflected wave signal, and a refracted wave signal;

[0039] Step 3: Processing the refraction wave data: extracting the refraction wave signal from the collected multi-source multi-wavefield data, synthesizing the collected multi-source multi-wavefield data of not less than the set number into single-shot multi-wavefield data, and obtaining the effective refraction wave signal from the single-shot multi-wavefield data, performing inversion, and obtaining the velocity distribution information within the set range of the preceding tunnel and the succeeding tunnel, and obtaining the continuous velocity profile of the to-be-excavated area of ​​the succeeding tunnel according to the obtained velocity distribution information;

[0040] Step 4: Interpretation of refraction wave data: Based on the continuous transverse velocity profile of the area to be excavated in the subsequent tunnel, combined with the geological information and structural distribution of the excavated section of the preceding tunnel, the geological interpretation of the geophysical data is realized;

[0041] Step 5: Comprehensive seismic multi-wave field and multi-view detection is based on the detection results obtained from the previous tunnel side wall detection, and the velocity profile obtained from the lateral detection is used as the initial model. The forward seismic wave reflection method is used for advance detection at the heading of the subsequent tunnel to obtain the distribution of adverse geological conditions perpendicular to the line direction.

[0042] The method of coupling the detector to the structure comprises:

[0043] S11, the trigger detector is fixed near the cutterhead in the shield body. A wide-band low-sensitivity detector is selected to reduce false triggering due to mechanical noise. The trigger detector is mainly used for the collection of excitation and self-seismic signals during TBM excavation and the trigger system of the forecasting equipment. This part of the signal needs to be filtered out from the collected signal during data processing later.

[0044] S12, the receiving detector needs to be fixed on the TBM body and coupled with the surrounding rock by means of a hydraulic strut. The detector is installed on the top of the strut, and the strut is remotely controlled by the host computer. When the test starts, the strut is automatically pushed onto the surrounding rock for data collection. After the data collection is completed, the strut is automatically retracted.

[0045] The method of selecting the offset distance according to the distance between the preceding tunnel and the succeeding tunnel includes:

[0046] The offset distance is determined by combining the distance between the preceding tunnel and the succeeding tunnel. According to the principle of refraction wave exploration, the detection depth h and the offset distance X1 satisfy the formula:

[0047] X1=2htan(θ c )

[0048] where θ c Critical Angle V1 is the wave velocity of the upper layer, V2 is the wave velocity of the lower layer medium, and the detection depth h = h1 + h2, where h1 represents the distance between the double-line tunnels, and h2 represents the cross-sectional width of the rear tunnel. This is used to calculate the offset distance X1 and the maximum offset distance X2. max Take 5-7 times the detection depth h, that is, 5h=<X max <=7h.

[0049] The specific steps for implementing the coherent stacking of TBM multi-source multi-wavefield data in the step (S3) are:

[0050] S31, signal filtering: The TBM multi-source seismic wave field data is filtered through spectrum analysis, correlation analysis and other processing methods. The frequency band range of effective signals, interference, etc. can be obtained through spectrum analysis. For the TBM rock-breaking source refraction wave, the effective spectrum range is the medium and low frequency band. Through filtering processing, the interference waves of the original seismic record can be effectively removed to highlight the effective signal.

[0051] S32, cross-correlation processing: By introducing the cross-correlation function to measure the similarity between TBM seismic wave data, one set of data f(t) is placed relative to another set of data g(t) in different amounts, and the corresponding values ​​in the two sets are multiplied and the product is obtained to obtain the cross-correlation value h(t):

[0052]

[0053] In the formula is the cross-correlation operator, and * is the convolution operator.

[0054] The seismic multi-wavefield multi-view comprehensive detection is based on the detection results obtained by the previous tunnel side wall detection, and the velocity profile obtained by the lateral detection is used as the initial model. The forward seismic wave reflection method is used for advance detection of the tunnel face to obtain the distribution of adverse geology perpendicular to the line direction, including:

[0055] S51: On-site implementation of seismic refraction wave detection of the side wall of the leading tunnel, and collection of transverse refraction wave data of the tunnel to be excavated; on-site implementation of seismic reflection wave detection of the working face of the trailing tunnel, and collection of longitudinal reflection wave data of the tunnel to be excavated;

[0056] S52, processing the data of the transverse detection refraction wave method to obtain the transverse velocity profile of the tunnel to be excavated, and extracting and digitizing the geometry of the subsequent tunnel section of the velocity profile;

[0057] S53, based on the transverse detection velocity profile, constructs the initial velocity model, conducts longitudinal detection (seismic wave reflection method) data processing and inversion work, and obtains the comprehensive interpretation results of the subsequent tunnel.

[0058] A system for continuous seismic wave detection in a double-line TBM tunnel construction, using the method for continuous seismic wave detection in a double-line TBM tunnel construction, comprising an 8-channel seismic detection device, a trigger detector, a receiving detector and a host computer module;

[0059] The 8-channel earthquake detection equipment, trigger detector and receiving detector are respectively connected to the host computer module.

[0060] Specifically, a method and system for continuous detection of seismic waves in a double-line TBM tunnel construction includes the following steps:

[0061] (S1) Observation system layout: The observation system layout method of cutting head excitation and side wall reception in the leading tunnel is adopted. The whole forecasting system is mounted on the TBM and uses 8-channel seismic detection equipment, 6 channels of which are used for receiving data collection, and 2 channels are used for triggering and TBM body self-seismic signal collection. The trigger detector is fixed to the cutterhead and is used for signal triggering and recording excitation and self-seismic signals. The receiving detector is arranged in a straight line on the side wall (near the side of the subsequent tunnel) on the same side, and is coupled with the surrounding rock of the side wall through hydraulic struts. The appropriate offset distance is selected according to the distance between the leading tunnel and the subsequent tunnel. The observation system parameters remain unchanged during the test. A fixed transmitting and receiving distance is used to detect the geological information of a fixed mileage section of the subsequent tunnel.

[0062] (S2) Continuous data acquisition: The software and hardware systems are controlled in real time by the host computer. Field testing is carried out when the leading tunnel is excavated normally. Fixed observation system parameters are used to continuously collect data as the cutterhead of the leading tunnel is excavated to achieve the goal of continuous detection of the subsequent tunnel. Since the seismic wave field excited by the rock breaking of the TBM is a multi-source multi-wave field seismic signal, multiple sets of data need to be collected continuously during field data collection. A single test continuously collects no less than 50 sets of data. The collected data includes wave field signals such as the body self-seismic signal, direct wave signal, reflected wave signal, and refracted wave signal.

[0063] (S3) Refraction wave data processing: It is necessary to extract the refraction wave signal from the collected multi-source multi-wave field data. To address the problem of multi-source seismic wave fields, the 50 sets of collected original data are synthesized into single-shot multi-channel data by using the coherent stacking of multi-source data and the refraction wave field picking technology. The effective refraction wave signal is picked up in the single-shot record, and the picked up refraction wave signal is inverted and calculated to obtain the velocity distribution information within a certain range of the leading tunnel and the succeeding tunnel. Through the continuous testing method of excavation and exploration, the continuous velocity profile of the area to be excavated in the succeeding tunnel is obtained.

[0064] (S4) Refraction wave data interpretation: Through the continuous detection working mode of the cutterhead vibration receiving side wall of the leading tunnel, the result is the continuous transverse velocity profile of the area to be excavated in the subsequent tunnel, which mainly reflects the structural distribution of the subsequent tunnel along the route direction (longitudinal direction). Combined with the geological information and structural distribution of the excavated section of the leading tunnel, the geological interpretation of the geophysical data is realized.

[0065] (S5) Comprehensive seismic detection with multiple wave fields and multiple fields of view: Based on the detection results obtained from the preceding tunnel side wall detection (lateral detection), the velocity profile obtained from the lateral detection is used as the initial model. The forward seismic wave reflection method is used to detect the tunnel face in advance (longitudinal detection) to obtain the distribution of unfavorable geology perpendicular to the line direction (lateral direction). Through the technical means of comprehensive detection of seismic refraction waves, seismic reflection waves, side walls and tunnel faces, a comprehensive seismic detection technology with multiple wave fields, multiple modes and multiple fields of view is realized to improve the accuracy of unfavorable geology detection.

[0066] The specific method of coupling the detector to the structure in step S1 is:

[0067] (S11) The trigger detector is fixed near the cutterhead in the shield body. A wide-band low-sensitivity detector is selected to reduce false triggering due to mechanical noise. The trigger detector is mainly used for the collection of excitation and self-seismic signals during TBM excavation and the trigger system of the forecasting equipment. This part of the signal needs to be filtered out from the collected signal during data processing in the later stage.

[0068] (S12) The receiving detector needs to be fixed on the TBM body and coupled with the surrounding rock by means of hydraulic struts. The detector is installed on the top of the struts, which are remotely controlled by the host computer. When the test starts, the struts are automatically pushed onto the surrounding rock for data collection. After the data collection is completed, the struts are automatically retracted. The specific structure of the hydraulic strut system is as follows: Figure 2 As shown:

[0069] In practice, the hydraulic strut system includes a base device 1, which is fixed on the TBM body. The top of the base device 1 is connected to the hydraulic strut 2, and the segments of the hydraulic strut 2 are connected by an associative device 3. The tail section hydraulic strut 3 and the transverse strut 5 are connected by a corner device 3. The transverse strut 5 is externally connected to a rotating motor 6, and the rotating motor 6 is externally connected to a rotating flying disc 7. The rotating motor 6 provides power, and the flying disc 7 is driven to rotate through a bearing 8. The rotating flying disc 7 is externally connected to two sets of miniature hydraulic struts 9 and 10, including a coupled drilling operation system and a detector placement system. The drilling operation system includes a hydraulic strut mother rod 9 and a sub-rod 11, and the sub-rod 11 is externally connected to a drilling rig 13 and a drill bit 14; the detector placement system includes a hydraulic strut mother rod 10 and a sub-rod 12, and the sub-rod 12 is externally connected to a mechanical claw drive system 15, and the drive system 15 is externally connected to a set of mechanical claws 16, and the detector 17 is automatically installed and disassembled through the mechanical claws 16.

[0070] The specific method for selecting the offset distance of the receiving detector in step S1 is: the offset distance is determined by combining the distance between the preceding tunnel and the succeeding tunnel. According to the principle of refraction wave exploration, the detection depth h and the offset distance X1 satisfy the formula: X1 = 2htan(θ c ), where θ c Critical Angle V1 is the wave velocity of the upper layer, V2 is the wave velocity of the lower layer medium, and the detection depth h = h1 + h2, where h1 represents the distance between the double-line tunnels, and h2 represents the cross-sectional width of the rear tunnel. This is used to calculate the offset distance X1 and the maximum offset distance X2. max Take 5-7 times the detection depth h, that is, 5h=<X max <=7h. The receiving channel spacing is not less than 5.0 meters. During the test, the observation system parameters are fixed, and a fixed receiving and transmitting distance is adopted. The detection depth is also fixed. The forecast system can detect the geological information of the fixed mileage section of the subsequent tunnel.

[0071] The specific steps for implementing the coherent stacking of TBM multi-source multi-wavefield data in step S3 are:

[0072] (S31) Signal filtering: The TBM multi-source seismic wave field data is filtered through spectrum analysis, correlation analysis and other processing methods. The frequency band range of effective signals, interference, etc. can be obtained through spectrum analysis. The effective spectrum range of the refraction wave of the TBM rock-breaking source is the medium and low frequency band. The interference wave of the original seismic record can be effectively removed through filtering processing, highlighting the effective signal.

[0073] (S32) Cross-correlation processing: By introducing a cross-correlation function to measure the similarity between TBM seismic wave data, one set of data f(t) is placed relative to another set of data g(t) by different amounts, and the corresponding values ​​in the two sets are multiplied and the product is obtained to obtain the cross-correlation value h(t):

[0074]

[0075] In the formula is the cross-correlation operator, and * is the convolution operator. An important property of the cross-correlation operation is that it can shorten the propagation time or propagation path as shown in the figure; Figure 3 In this example, it can be seen that after the cross-correlation operation, the source position has been reconverted to the position of the detector near the source.

[0076] (S33) Coherent stacking of multi-channel data: The multi-source data coherent stacking processing method is used for the multi-channel seismic data after cross-correlation processing, and the coherent stacking calculation is performed on the 50 collected original data, so as to further remove random interference factors, strengthen the effective wave field signal, and synthesize the 50 multi-source multi-wave field data into single-shot multi-wave field data.

[0077] The specific method for realizing the geological interpretation of longitudinal detection in step S4 is as follows: due to the working mode of receiving the side wall of the leading tunnel, the structural surface of the detection results is mainly distributed along the axis of the tunnel: the velocity profile of the whole section from the side wall of the leading tunnel to the body of the following tunnel is realized, so as to realize the longitudinal detection of the unfavorable geology of the tunnel to be excavated; when interpreting the results, the prior geological information of the leading tunnel: the outcrop of the surrounding rock of the side wall, lithology, occurrence, existing structure and other information are combined with the results of the longitudinal geophysical detection to carry out a comprehensive interpretation, so as to improve the reliability of the interpretation results, such as Figure 4 shown.

[0078] The specific steps for implementing the seismic multi-wavefield multi-view comprehensive detection technology in step S5 are:

[0079] (S51) conducting on-site detection of the side wall of the first tunnel using the seismic refraction wave method, collecting transverse refraction wave data of the tunnel to be excavated, conducting on-site detection of the working face of the second tunnel using the seismic reflection wave method, collecting longitudinal reflection wave data of the tunnel to be excavated;

[0080] (S52) processing the data of the transverse detection refraction wave method to obtain the transverse velocity profile of the tunnel to be excavated, and extracting and digitizing the geometry of the subsequent tunnel section of the velocity profile;

[0081] (S53) Based on the transverse detection velocity profile, an initial velocity model is constructed, and longitudinal detection (seismic wave reflection method) data processing and inversion work are carried out to obtain a comprehensive interpretation result of the subsequent tunnel. The comprehensive result integrates the information of the seismic wave reflection method and the refraction wave method. Through the comprehensive detection technology of multi-wave field (reflection wave and refraction wave), multi-mode (prior geological information, prior structure, geophysical exploration results), and multi-field of view (preliminary tunnel side wall and subsequent tunnel face), the accuracy of adverse geological detection in the subsequent tunnel is improved.

[0082] The above is only a preferred embodiment of the present invention. It should be understood that the present invention is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the concept described herein through the above teachings or the technology or knowledge of the relevant field. The changes and modifications made by those skilled in the art shall not deviate from the spirit and scope of the present invention, and shall be within the scope of protection of the claims attached to the present invention.

Claims

1. A method for continuous detection of seismic waves in a double-line TBM tunnel construction, characterized in that: The steps include: Step 1: Set up the observation system, using 8-channel seismic detection equipment, of which 6 channels are used for data acquisition and 2 channels are used to collect TBM body self-seismic signals; the trigger detector is fixed to the TBM cutterhead to record the self-seismic signals; the receiving detector is arranged in a straight line on the same side wall and coupled with the side wall surrounding rock through hydraulic struts; the offset distance is selected according to the distance between the preceding tunnel and the succeeding tunnel, and the fixed transmitting and receiving distance is used for data acquisition; Step 2: Continuous data collection: data collection is performed during the advance tunnel excavation, and continuous data collection is performed as the cutterhead excavates. A single test continuously collects not less than a set number of multi-source multi-wavefield data, wherein the multi-source multi-wavefield data includes a fuselage self-seismic signal, a direct wave signal, a reflected wave signal, and a refracted wave signal; Step 3: Processing the refraction wave data: extracting the refraction wave signal from the collected multi-source multi-wavefield data, synthesizing the collected multi-source multi-wavefield data of not less than the set number into single-shot multi-wavefield data, and obtaining the effective refraction wave signal from the single-shot multi-wavefield data, performing inversion, and obtaining the velocity distribution information within the set range of the preceding tunnel and the succeeding tunnel, and obtaining the continuous velocity profile of the to-be-excavated area of ​​the succeeding tunnel according to the obtained velocity distribution information; Step 4: Interpretation of refraction wave data: Based on the continuous transverse velocity profile of the area to be excavated in the subsequent tunnel, combined with the geological information and structural distribution of the excavated section of the preceding tunnel, the geological interpretation of the geophysical data is realized; Step 5: Comprehensive seismic multi-wave field and multi-view detection is based on the detection results obtained from the previous tunnel side wall detection, and the velocity profile obtained from the lateral detection is used as the initial model. The forward seismic wave reflection method is used for advance detection at the heading of the subsequent tunnel to obtain the distribution of adverse geological conditions perpendicular to the line direction.

2. A method for continuous detection of seismic waves in a double-line TBM tunnel construction according to claim 1, characterized in that , the method of coupling the detector to the structure includes: S11, the trigger detector is fixed near the cutterhead in the shield body. A wide-band low-sensitivity detector is selected to reduce false triggering due to mechanical noise. The trigger detector is mainly used for the collection of excitation and self-seismic signals during TBM excavation and the trigger system of the forecasting equipment. This part of the signal needs to be filtered out from the collected signal during data processing later. S12, the receiving detector needs to be fixed on the TBM body and coupled with the surrounding rock by means of a hydraulic strut. The detector is installed on the top of the strut, and the strut is remotely controlled by the host computer. When the test starts, the strut is automatically pushed onto the surrounding rock for data collection. After the data collection is completed, the strut is automatically retracted.

3. A method for continuous detection of seismic waves in a double-line TBM tunnel construction according to claim 1, characterized in that , the said selecting the offset distance according to the distance between the preceding tunnel and the succeeding tunnel includes: The offset distance is determined by combining the distance between the preceding tunnel and the succeeding tunnel. According to the principle of refraction wave exploration, the detection depth h and the offset distance X1 satisfy the formula: X1=2htan(θ c ) where θ c Critical Angle V1 is the wave velocity of the upper layer, V2 is the wave velocity of the lower layer medium, and the detection depth h = h1 + h2, where h1 represents the distance between the double-line tunnels, and h2 represents the cross-sectional width of the rear tunnel. This is used to calculate the offset distance X1 and the maximum offset distance X2. max Take 5-7 times the detection depth h, that is, 5h=<X max <=7h.

4. A method for continuous detection of seismic waves in a double-line TBM tunnel construction according to claim 1, characterized in that The specific steps for implementing the coherent superposition of multi-source multi-wavefield data are as follows: S31, signal filtering: The TBM multi-source seismic wave field data is filtered through spectrum analysis, correlation analysis and other processing methods. The frequency band range of effective signals, interference, etc. can be obtained through spectrum analysis. For the TBM rock-breaking source refraction wave, the effective spectrum range is the medium and low frequency band. Through filtering processing, the interference waves of the original seismic record can be effectively removed to highlight the effective signal. S32, cross-correlation processing: By introducing the cross-correlation function to measure the similarity between TBM seismic wave data, one set of data f(t) is placed relative to another set of data g(t) in different amounts, and the corresponding values ​​in the two sets are multiplied and the product is obtained to obtain the cross-correlation value h(t): In the formula is the cross-correlation operator, and * is the convolution operator.

5. A method for continuous detection of seismic waves in a double-line TBM tunnel construction according to claim 1, characterized in that The seismic multi-wave field multi-view comprehensive detection is based on the detection results obtained by the previous tunnel side wall detection, and the velocity profile obtained by the lateral detection is used as the initial model. The forward seismic wave reflection method is used for advance detection of the tunnel face to obtain the distribution of adverse geology perpendicular to the line direction, including: S51: On-site implementation of seismic refraction wave detection of the side wall of the leading tunnel, and collection of transverse refraction wave data of the tunnel to be excavated; on-site implementation of seismic reflection wave detection of the working face of the trailing tunnel, and collection of longitudinal reflection wave data of the tunnel to be excavated; S52, processing the data of the transverse detection refraction wave method to obtain the transverse velocity profile of the tunnel to be excavated, and extracting and digitizing the geometry of the subsequent tunnel section of the velocity profile; S53, based on the transverse detection velocity profile, constructs the initial velocity model, performs longitudinal detection (seismic wave reflection method) data processing and inversion work, and obtains the comprehensive interpretation results of the subsequent tunnel.

6. A continuous seismic wave detection system for double-line TBM tunnel construction, characterized in that: A method for continuous seismic wave detection in a double-line TBM tunnel construction as described in any one of claims 1 to 5, comprising an 8-channel seismic detection device, a trigger detector, a receiving detector and a host computer module; The 8-channel earthquake detection equipment, trigger detector and receiving detector are respectively connected to the host computer module.

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