Active and passive source combined geological detection method and system for shield tunnel

Abstract

An active and passive source combined geological detection method for a shield tunnel. The method comprises: acquiring an active-source seismic-wave reflected signal and a passive-source acoustic-wave reflected signal; on the basis of the active-source seismic-wave reflected signal, obtaining an active-source geological detection imaging result by using a longitudinal and transverse wave combined imaging principle; on the basis of the passive-source acoustic-wave reflected signal, obtaining a passive-source geological detection imaging result by using a frequency dispersion extraction-transverse wave velocity inversion method that fuses spatial autocorrelation and a half-wavelength model; and by using the active-source geological detection imaging result as a main part and the passive-source geological detection imaging result as an auxiliary part, and in view of an adaptive adjustment coefficient therebetween, obtaining an adverse geological risk level of a region to be detected.

Description

A combined active and passive source geological exploration method and system for shield tunnels

[0001] Cross-reference to related applications

[0002] This invention claims priority to Chinese Patent Application No. 202411470515.8, filed on October 21, 2024, entitled "A Method and System for Combined Active and Passive Source Geological Exploration of Shield Tunnels", the entire contents of which are incorporated herein by reference and constitute a part of this invention for all purposes. Technical Field

[0003] This invention relates to the field of geological exploration technology, and in particular to a method and system for combined active and passive source geological exploration of shield tunnels. Background Technology

[0004] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0005] With the widespread use of tunnel boring machines (TBMs) in tunnel construction, the prevention and control of disasters during TBM tunnel construction has received increasing attention, especially in urban rail transit construction, such as subways. These projects face adverse geological conditions including undulating bedrock surfaces, karst formations, isolated boulders, and uneven rock textures, posing risks such as sudden water inrushes, ground instability, machine damage, and surface subsidence. These risks can range from affecting construction progress to causing major engineering accidents, sometimes resulting in significant economic losses and casualties. Therefore, identifying adverse geological conditions ahead of the TBM tunnel is crucial for effectively mitigating geological hazards and ensuring the safe construction of TBM tunnels.

[0006] As tunnel depth increases, terrain complexity grows, and surface exploration technology becomes limited, the geological problems encountered during tunnel construction become increasingly complex, and safety hazards become more varied and diverse. Traditional detection methods that rely solely on artificial instantaneous seismic sources or environmental noise sources are unable to balance detection depth and resolution, thus affecting the accuracy of geological exploration. Summary of the Invention

[0007] To address the aforementioned issues, this invention proposes a combined active and passive source geological exploration method and system for shield tunnels. It introduces high-energy, wide-bandwidth shield tunneling vibration noise as a passive detection source, using active source geological exploration imaging results as the primary source and passive source geological exploration imaging results as a secondary source, thereby improving the detection depth and resolution and providing support for accurate geological imaging.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] In a first aspect, the present invention provides a method for combined active and passive source geological exploration of shield tunnels, comprising:

[0010] The active source seismic wave reflection signal and the passive source acoustic wave reflection signal are acquired; wherein, the active source seismic wave reflection signal is the seismic wave signal excited by the excitation device mounted on the tunnel boring machine after the shield body contacts the surrounding rock; the passive source acoustic wave reflection signal is the acoustic wave signal generated by the shield cutterhead during the tunneling process;

[0011] Based on the reflection signals of active source seismic waves, the active source geological exploration imaging results are obtained by using the principle of combined P-wave and S-wave imaging.

[0012] Based on the passive source acoustic wave reflection signal, the dispersion extraction-transverse wave velocity inversion method that integrates spatial autocorrelation and half-wavelength model is used to obtain the passive source geological exploration imaging results.

[0013] The adverse geological risk level of the area to be measured is obtained by using active source geological exploration imaging results as the main method and passive source geological exploration imaging results as a supplement, and combining the adaptive adjustment coefficient between the two.

[0014] As an alternative implementation method, the process of obtaining active source geological exploration imaging results includes:

[0015] After wideband and wide-view velocity filtering by FK transform, fine-parameter re-filtering is performed by linear Radon transform to extract complex wavefield reflected waves.

[0016] Given the true superposition velocity, the average amplitude energy and average amplitude are maximized, and the three-dimensional spatial wave velocity is analyzed through the average amplitude energy and average amplitude.

[0017] The Kirchhoff depth migration method is used for detection and imaging processing, which involves determining the seismic wave propagation distance based on the surrounding rock wave velocity and the seismic wave propagation time for a fixed source excitation point and signal receiving point.

[0018] As an alternative implementation method, the process of obtaining passive source geological exploration imaging results includes:

[0019] A time-division Fourier transform is performed on the passive source acoustic wave reflection signal to construct a spatial autocorrelation equation, thereby constructing a dispersion curve model.

[0020] A half-wavelength model is derived from the half-wave field theory to solve for the transverse wave velocity.

[0021] Using a detection spatial range and grid subdivision method, and assuming that each grid node is a reflection point, the travel time under the propagation path is obtained based on the positional relationship between the source point, receiver point, and emission point and the given surrounding rock wave velocity. The corresponding instantaneous amplitude value is obtained according to the travel time of the source point and receiver point. The instantaneous amplitudes at the same grid node are superimposed. If the reflection point is the actual interface location, the amplitude will have a maximum value.

[0022] As an alternative implementation, a three-component geophone is installed on the shield of the tunnel boring machine to collect the reflected signals of active source seismic waves. The three-component geophone is connected to the active source demodulator via a wired connection to send the reflected signals of active source seismic waves to the demodulator, and the relevant results are uploaded to the cloud for joint calculation via a data network connection.

[0023] As an alternative implementation, passive source sensors are linearly deployed along the tunnel boring direction to collect passive source acoustic wave reflection signals. The passive source sensors are connected to a passive source demodulator via a wired connection to send the passive source acoustic wave reflection signals to the demodulator, and the relevant results are uploaded to the cloud for joint calculation via a data network connection.

[0024] Secondly, the present invention provides a combined active and passive source geological exploration system for shield tunnels, comprising:

[0025] The acquisition module is configured to acquire active source seismic wave reflection signals and passive source acoustic wave reflection signals; wherein, the active source seismic wave reflection signal is the seismic wave signal excited by the excitation device mounted on the tunnel boring machine after the shield body contacts the surrounding rock; the passive source acoustic wave reflection signal is the acoustic wave signal generated by the shield cutterhead during the tunneling process;

[0026] The active source detection module is configured to obtain active source geological detection imaging results based on the active source seismic wave reflection signal and the P-wave and S-wave combined imaging principle.

[0027] The passive source detection module is configured to obtain passive source geological detection imaging results based on the passive source acoustic wave reflection signal by using a dispersion extraction-transverse wave velocity inversion method that integrates spatial autocorrelation and half-wavelength model.

[0028] The joint detection module is configured to primarily use active source geological detection imaging results, supplemented by passive source geological detection imaging results, and combine the adaptive adjustment coefficients between the two to obtain the adverse geological risk level of the area to be measured.

[0029] Thirdly, the present invention provides a shield tunnel active and passive source combined geological exploration system, comprising: an excitation device and a three-component geophone mounted on the shield machine, a passive source sensor deployed along the shield tunneling direction, an active source demodulator wired to the three-component geophone, a passive source demodulator wired to the passive source sensor, and an active and passive source combined computing cloud connected to the active source demodulator and the passive source demodulator via a data network.

[0030] The three-component geophone is used to collect the seismic wave signal generated after the excitation device strikes the shield and contacts the surrounding rock, and sends it to the active source demodulator.

[0031] The passive source sensor is used to collect the acoustic signals generated by the shield cutterhead during the tunneling process and send them to the passive source demodulator.

[0032] The active source demodulator is used to obtain active source detection results based on the seismic wave signal using the method described in the first aspect;

[0033] The passive source is used to obtain the passive source detection result based on the acoustic wave signal using the method described in the first aspect;

[0034] The cloud-based active and passive source joint computing system obtains the adverse geological risk level of the area to be tested by using the method described in the first aspect, based on the detection results of the active and passive sources.

[0035] Fourthly, the present invention provides an electronic device including a memory and a processor, and computer instructions stored in the memory and running on the processor, wherein the computer instructions, when executed by the processor, perform the method described in the first aspect.

[0036] Fifthly, the present invention provides a computer-readable storage medium for storing computer instructions, which, when executed by a processor, perform the method described in the first aspect.

[0037] In a sixth aspect, the present invention provides a computer program product, including a computer program that, when executed by a processor, implements the method described in the first aspect.

[0038] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0039] This invention proposes a combined active and passive source geological exploration method and system for shield tunnels. It introduces the high-energy, wide-bandwidth shield tunneling vibration noise as a passive detection source. The active source geological exploration imaging results are obtained based on the reflection signals of the active source seismic waves, and the passive source geological exploration imaging results are obtained based on the reflection signals of the passive source acoustic waves. The active source geological exploration imaging results are the primary source, and the passive source geological exploration imaging results are the secondary source, which improves the detection depth and resolution of geological prediction and enables rapid and accurate acquisition of adverse geological information ahead of shield tunneling.

[0040] This invention proposes a combined active and passive source geological exploration method and system for shield tunnels. Geological prediction is carried out simultaneously with shield tunneling machine construction, without the need for the shield tunneling machine to stop for coordination, and without specifically occupying shield tunneling working time. This is conducive to making full use of the working efficiency of the shield tunneling machine, has good adaptability to shield tunnel construction, and reduces the impact of factors such as metal in the tunnel on data acquisition.

[0041] Advantages of additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0042] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0043] Figure 1 is a flowchart of the shield tunnel active and passive source combined geological exploration method provided in Embodiment 1 of the present invention;

[0044] Figure 2 is a structural diagram of the shield tunnel active and passive source combined geological exploration method provided in Embodiment 1 of the present invention.

[0045] The components include: 1. Shield body; 2. Three-component geophone; 3. Wired connection; 4. Active source demodulator; 5. Excitation hammer equipment; 6. Shield cutterhead; 7. Ground; 8. Passive source sensor; 9. Passive source demodulator; 10. Data network connection; 11. Active and passive source joint computing cloud. Detailed Implementation

[0046] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0047] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0048] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments of the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. Furthermore, it should be understood that the terms “comprising” and “having”, and any variations thereof, are intended to cover non-exclusive inclusion, for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0049] Where there is no conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0050] Example 1

[0051] As shown in Figure 1, this embodiment provides a method for combined active and passive source geological exploration of shield tunnels, including:

[0052] The active source seismic wave reflection signal and the passive source acoustic wave reflection signal are acquired; wherein, the active source seismic wave reflection signal is the seismic wave signal excited by the excitation device mounted on the tunnel boring machine after the shield body contacts the surrounding rock; the passive source acoustic wave reflection signal is the acoustic wave signal generated by the shield cutterhead during the tunneling process;

[0053] Based on the reflection signals of active source seismic waves, the active source geological exploration imaging results are obtained by using the principle of combined P-wave and S-wave imaging.

[0054] Based on the passive source acoustic wave reflection signal, the dispersion extraction-transverse wave velocity inversion method that integrates spatial autocorrelation and half-wavelength model is used to obtain the passive source geological exploration imaging results.

[0055] The adverse geological risk level of the area to be measured is obtained by using active source geological exploration imaging results as the main method and passive source geological exploration imaging results as a supplement, and combining the adaptive adjustment coefficient between the two.

[0056] In this embodiment, as shown in Figure 2, an active source shield cutterhead 6 is mounted on the shield body 1 of the tunnel boring machine. The excitation hammering equipment 5 strikes the shield body 1 into contact with the surrounding rock to efficiently excite seismic wave signals. A three-component geophone 2 is arranged behind the excitation hammering equipment 5 on the shield body 1 to collect seismic wave signals reflected back from the front reflecting surface. The three-component geophone 2 is connected to the active source demodulator 4 via a wired connection 3 to send the active source seismic wave reflection signal to the active source demodulator 4. Based on the elastic wave reflection method, it inverts and predicts adverse geological conditions such as faults and karst caves. The processing results are transmitted to the active and passive source joint computing cloud 11 via the data network connection 10 for subsequent active and passive source joint prediction.

[0057] The specific process of active source geological exploration imaging is as follows: During the assembly of tunnel boring machine segments, the segments are hammered by an onboard excitation hammer device, which efficiently excites seismic wave signals and propagates them in all directions in the form of spherical waves. According to the Huygens-Fresnel principle and Fermat's principle, when there is an interface between two different solid media in the propagation path of the sound wave, the wave propagation will undergo refraction, reflection and wave mode conversion. The three-component geophone at the rear receives the elastic waves reflected by the geological surface. After data preprocessing and waveform processing, the complex wave field reflection wave extraction and three-dimensional spatial wave velocity analysis are performed according to the principle of combined longitudinal and transverse wave imaging. Finally, the active source geological exploration imaging results are obtained by using Kirchhoff integral migration imaging.

[0058] The specific inversion process is as follows:

[0059] (1-1) Data preprocessing: to achieve data quality evaluation, bad channel removal, editing and correction, and effective data extraction (depending on the detection distance), so that subsequent signal processing is focused and efficient, and the observation system layout is parameterized.

[0060] (1-2) Seismic data waveform processing: The improved Butterworth bandpass filtering method is used to process the seismic wave reflection signal. Its transfer function expression is shown in Equation (1).

[0061] Among them, H 1P (u, v) refers to the nth-order improved Butterworth low-pass filter with a cutoff frequency of D; D(u, v) is the distance from point (u, v) to the center of the frequency rectangle (M / 2, N / 2); D is the cutoff frequency; n is the improvement order.

[0062] (1-3) Extraction of Reflected Waves from Complex Wavefields: Complex wavefields refer to situations in practical applications where various interferences cause the effective signal in the acquired signal to be masked by various useless signals. Single filtering methods such as FK filtering and τ-p filtering have certain limitations. Wavefield separation and noise reduction are crucial steps in signal processing; therefore, this invention proposes a joint FK and τ-p filtering method. 1) First, wideband and wide-view velocity filtering is achieved through FK transform to eliminate the high-energy downlink waves while filtering out high- and low-frequency noise signals; 2) Second, a refined parameter re-filtering is performed using the linear Radon transform method to truly achieve the extraction and denoising of the effective wavefield.

[0063] (1-4) Three-dimensional spatial wave velocity analysis: The wave number is analyzed by using the diffraction scanning superposition velocity analysis method. The analysis is mainly based on the joint determination of two parameters: average amplitude energy and average amplitude. That is, given the true superposition velocity, the average amplitude energy or amplitude will reach a maximum value.

[0064] The specific process of the diffraction scanning superposition velocity analysis method is as follows:

[0065] Step 1: Determine the velocity scanning range. Based on the first arrival picking and seismic time-base correction processed seismic data, obtain the direct wave velocity, which is used as a reference for the wave velocity scanning range, and combined with engineering geological data and actual geological conditions.

[0066] Step 2: Define the detection space range in front of the shield tunnel excavation face. Generally, the advance detection range is about 30-50m deep, and should also include the space behind the excavation face where the observation system is located (about 20m). This space range is then divided into a fine grid profile. In practice, it has been found that a grid size of about 0.5-2m generally meets the accuracy requirements.

[0067] Step 3: Calculate the seismic travel time parameter table. Based on the given wave velocity range and step size, calculate the seismic travel time corresponding to each time node, that is, the travel time corresponding to the scanning velocity can be obtained for each node:

[0068] In the formula: S1 and S2 are the distances between the node and the seismic source and the sensor, respectively; v0 is the initial velocity; Δv is the velocity step size; t(i) is the travel time used for the current scanning velocity.

[0069] Step 4: Generate the seismic record corresponding to each time node. An amplitude value is assigned to each grid node. However, considering the discreteness of seismic gather records in actual exploration, not every travel time has a corresponding amplitude value. Therefore, the Lagrange interpolation method is used to obtain the amplitude value at that node.

[0070] Step 5: Stack the amplitude values ​​corresponding to each diffraction profile. If the scanning speed equals the stacking speed, similar waveform recording points can be found on different seismic records. After coherent stacking, an amplitude extremum can be obtained. Calculate the amplitude extremum corresponding to each node according to the process to determine the stacking speed parameters.

[0071] (1-5) Detection and Imaging: For a given reflection point, it, along with the source point and the receiver point, forms an ellipse of fixed length r. If the pre-given wave velocity is the actual surrounding rock wave velocity, the corresponding amplitude value during travel is distributed onto the elliptical trajectory. Then, considering factors such as propagation distance, reflection angle, and phase transformation, the amplitude is corrected for tilt, length, and phase. Finally, the amplitude is redistributed onto the ellipse. This is the entire process of Kirchhoff integral migration imaging, and the specific implementation path is as follows:

[0072] The first step is to use the same detection space range and grid partitioning method as the velocity analysis, and assume that each grid node is a reflection point;

[0073] The second step is to obtain the travel time along the propagation path based on the positional relationship between the source point, receiver point, and transmitter point and the given wave velocity in the surrounding rock.

[0074] The third step involves finding the corresponding instantaneous amplitude value based on the travel time between the source and receiver points. The instantaneous amplitudes at the same grid node are then superimposed. If the reflection point is the actual interface location, the amplitude will reach a maximum. Conversely, the superimposed amplitudes will approach zero.

[0075] The fourth step is to connect the extreme values ​​of the amplitude at each point, interpolate and fit to draw an amplitude profile. Based on the geology of the excitation point, the geological changes of the reflection point in front relative to the excitation point can be known. Positive numbers indicate the same geology, while negative numbers indicate a looser geology.

[0076] In this embodiment, as shown in Figure 2, passive source sensors 8 are linearly arranged on the ground 7 along the tunneling direction. During the tunneling process, the cutterhead 7 of the tunnel boring machine generates a large number of broadband acoustic signals and propagates in all directions. The passive source sensors 8 arranged on the ground along the tunneling direction receive the broadband signals reflected back by the tunneling noise as a passive source. The passive source sensors 8 and the passive source demodulator 9 are connected by a wired connection 3 to send the passive source acoustic wave reflection signals to the passive source demodulator 9 for inversion and prediction of adverse geological conditions such as isolated boulders and soft-hard interfaces. The processing results are transmitted to the main and passive source joint computing cloud 11 through the data network connection 10 for subsequent main and passive source joint prediction.

[0077] The specific process of passive source geological exploration imaging is as follows: During shield tunneling, the cutterhead tools generate powerful acoustic signals and propagate in all directions in the form of spherical waves. Based on the seismic wave data received by the passive source sensors, the adverse geological inversion method that integrates spatial autocorrelation and half-wavelength model is adopted to realize passive source geological prediction imaging of shield tunnels.

[0078] The specific process is as follows:

[0079] (2-1) The implementation methods for data preprocessing, waveform processing and other processes are the same as those for the aforementioned active source, and will not be repeated here.

[0080] (2-2) Dispersion curve extraction: Perform time-division Fourier transform on the processed random noise signal to extract data of each frequency. Based on this, calculate the spatial autocorrelation coefficient between sensors. After azimuth averaging, obtain the spatial autocorrelation coefficient under this arrangement. Fit the obtained spatial autocorrelation coefficient with the first-order zero-order Bessel function to obtain the phase velocity at each frequency. The obtained curve is the dispersion curve.

[0081] (2-3) Shear wave velocity inversion: The extracted dispersion curves are subjected to multi-mode surface wave joint inversion based on mode identification to obtain the one-dimensional velocity curves at the measurement points. This part mainly includes two stages: the first stage establishes an initial model and uses the extracted fundamental mode dispersion curves for inversion calculation; the second stage uses the inversion results of the fundamental mode as the updated initial model, and incorporates the dispersion curves of each mode into the inversion process for optimization and fitting.

[0082] (2-4) Inversion imaging: Repeat steps (2) and (3) for each measuring point to obtain the inversion results of all measuring points, and interpolate and fit to draw the shear wave velocity profile, thereby obtaining the geological information within the engineering survey range and realizing the refined exploration of the complex urban environment.

[0083] The geological conditions can be qualitatively interpreted based on the changes in the dispersion curve. At a certain point, the lower phase velocity indicates that the geology is more fragmented and the rock mass is weaker, while the higher phase velocity indicates that the geology is more intact and the rock mass is stronger. A large variation in phase velocity indicates that there may be weak interlayers or isolated boulders at that location.

[0084] In this embodiment, the process of combined active and passive source geological exploration includes: taking the active source geological exploration imaging results as the main method and the passive source geological exploration imaging results as the auxiliary method, combining geological exploration data, comprehensively considering the active and passive source geological exploration results, and finally determining the adverse geological risk level of the area to be tested, thereby improving the exploration depth and resolution and providing support for accurate geological imaging.

[0085] Example 2

[0086] This embodiment provides a combined active and passive source geological exploration system for shield tunnels, including:

[0087] The acquisition module is configured to acquire active source seismic wave reflection signals and passive source acoustic wave reflection signals; wherein, the active source seismic wave reflection signal is the seismic wave signal excited by the excitation device mounted on the tunnel boring machine after the shield body contacts the surrounding rock; the passive source acoustic wave reflection signal is the acoustic wave signal generated by the shield cutterhead during the tunneling process;

[0088] The active source detection module is configured to obtain active source geological detection imaging results based on the active source seismic wave reflection signal and the P-wave and S-wave combined imaging principle.

[0089] The passive source detection module is configured to obtain passive source geological detection imaging results based on the passive source acoustic wave reflection signal by using a dispersion extraction-transverse wave velocity inversion method that integrates spatial autocorrelation and half-wavelength model.

[0090] The joint detection module is configured to primarily use active source geological detection imaging results, supplemented by passive source geological detection imaging results, and combine the adaptive adjustment coefficients between the two to obtain the adverse geological risk level of the area to be measured.

[0091] It should be noted that the above modules correspond to the steps described in Embodiment 1, and the examples and application scenarios implemented by the above modules and the corresponding steps are the same, but are not limited to the content disclosed in Embodiment 1. It should also be noted that the above modules, as part of the system, can be executed in a computer system such as a set of computer-executable instructions.

[0092] In further embodiments, the following is also provided:

[0093] A shield tunnel active and passive source combined geological exploration system includes: an excitation device and a three-component geophone mounted on the shield machine, a passive source sensor deployed along the shield tunneling direction, an active source demodulator wired to the three-component geophone, a passive source demodulator wired to the passive source sensor, and an active and passive source combined computing cloud connected to the active source demodulator and the passive source demodulator via a data network.

[0094] The three-component geophone is used to collect the seismic wave signal generated after the excitation device strikes the shield and contacts the surrounding rock, and sends it to the active source demodulator.

[0095] The passive source sensor is used to collect the acoustic signals generated by the shield cutterhead during the tunneling process and send them to the passive source demodulator.

[0096] The active source demodulator is used to obtain active source detection results based on the seismic wave signal using the method described in Example 1. Specifically, the active source demodulator is used to preliminarily process the seismic wave signal collected by the three-component geophone and upload the processing result to the cloud for joint calculation via a data network connection.

[0097] The passive source is used to obtain the passive source detection result based on the acoustic signal using the method described in Example 1. Specifically, the passive source demodulator is used to preliminarily process the passive source acoustic signal collected by the passive source sensor and upload the processing result to the cloud for joint calculation via a data network connection.

[0098] The active and passive source joint computing cloud obtains the adverse geological risk level of the area to be tested based on the detection results of the active and passive sources, using the method described in Example 1. Specifically, the active and passive source joint computing cloud receives the processing results from the active source demodulator and the passive source demodulator, and combines the adaptive adjustment coefficients of the two to obtain the adverse geological risk level of the area to be tested.

[0099] In further embodiments, the following is also provided:

[0100] An electronic device includes a memory and a processor, as well as computer instructions stored in the memory and running on the processor, wherein the computer instructions, when executed by the processor, perform the method described in Embodiment 1. For brevity, further details are omitted here.

[0101] It should be understood that in this embodiment, the processor can be a central processing unit (CPU), or it can be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or any conventional processor, etc.

[0102] Memory may include read-only memory and random access memory, and provides instructions and data to the processor. A portion of memory may also include non-volatile random access memory. For example, memory may also store information about the device type.

[0103] A computer-readable storage medium for storing computer instructions, which, when executed by a processor, perform the method described in Embodiment 1.

[0104] The method in Example 1 can be directly implemented by a hardware processor, or implemented by a combination of hardware and software modules within the processor. The software modules can reside in readily available storage media in the field, such as random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, or registers. This storage medium is located in memory, and the processor reads information from the memory and, in conjunction with its hardware, completes the steps of the above method. To avoid repetition, a detailed description is not provided here.

[0105] A computer program product includes a computer program that, when executed by a processor, implements the method described in Embodiment 1.

[0106] The present invention also provides at least one computer program product tangibly stored on a non-transitory computer-readable storage medium. The computer program product includes computer-executable instructions, such as instructions included in program modules, which execute in a device on a target real or virtual processor to perform the processes / methods described above. Typically, program modules include routines, programs, libraries, objects, classes, components, data structures, etc., that perform specific tasks or implement specific abstract data types. In various embodiments, the functionality of program modules can be combined or divided among program modules as needed. The machine-executable instructions for the program modules can execute within a local or distributed device. In a distributed device, the program modules can reside in both local and remote storage media.

[0107] The computer program code used to implement the methods of the present invention may be written in one or more programming languages. This computer program code may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, such that when executed by the computer or other programmable data processing device, the program code causes the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The program code may be executed entirely on a computer, partially on a computer, as a stand-alone software package, partially on a computer and partially on a remote computer, or entirely on a remote computer or server.

[0108] In the context of this invention, computer program code or related data may be carried by any suitable carrier to enable a device, apparatus, or processor to perform the various processes and operations described above. Examples of carriers include signals, computer-readable media, and so on. Examples of signals may include electrical, optical, radio, sound, or other forms of propagation signals, such as carrier waves, infrared signals, etc.

[0109] Those skilled in the art will recognize that the units and algorithm steps described in conjunction with the embodiments herein can be implemented in electronic hardware or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0110] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A method for combined active and passive source geological exploration of shield tunnels, characterized in that, include: The active source seismic wave reflection signal and the passive source acoustic wave reflection signal are obtained; wherein, the active source seismic wave reflection signal is the seismic wave signal excited by the excitation device mounted on the tunnel boring machine after the shield body contacts the surrounding rock, and the passive source acoustic wave reflection signal is the acoustic wave signal generated by the shield cutterhead during the tunneling process. Based on the reflection signals of active source seismic waves, the active source geological exploration imaging results are obtained by using the principle of combined P-wave and S-wave imaging. Based on the passive source acoustic wave reflection signal, a dispersion extraction-transverse wave velocity inversion method integrating spatial autocorrelation and half-wavelength model is used to obtain the passive source geological exploration imaging results. The process includes: A time-division Fourier transform is performed on the passive source acoustic wave reflection signal to construct a spatial autocorrelation equation, thereby constructing a dispersion curve model. A half-wavelength model is derived from the half-wave field theory to solve for the transverse wave velocity. Using a detection spatial range and grid partitioning method, and assuming that each grid node is a reflection point, the travel time under the propagation path is obtained based on the positional relationship between the source point, receiver point, and emission point and the given surrounding rock wave velocity. The corresponding instantaneous amplitude value is obtained according to the travel time of the source point and receiver point. The instantaneous amplitudes at the same grid node are superimposed. If the reflection point is the actual interface location, the amplitude will have a maximum value. The adverse geological risk level of the area to be measured is obtained by using active source geological exploration imaging results as the main method and passive source geological exploration imaging results as a supplement, and combining the adaptive adjustment coefficient between the two.

2. The method for combined active and passive source geological exploration of shield tunnels as described in claim 1, characterized in that, The process of obtaining active source geological exploration imaging results includes: After wideband and wide-view velocity filtering by FK transform, fine-parameter re-filtering is performed by linear Radon transform to extract complex wavefield reflected waves. Given the true superposition velocity, the average amplitude energy and average amplitude are maximized, and the three-dimensional spatial wave velocity is analyzed through the average amplitude energy and average amplitude. The Kirchhoff depth migration method is used for detection and imaging processing, which involves determining the seismic wave propagation distance based on the surrounding rock wave velocity and the seismic wave propagation time for a fixed source excitation point and signal receiving point.

3. The method for combined active and passive source geological exploration of shield tunnels as described in claim 1, characterized in that, Three-component geophones are installed on the shield of the tunnel boring machine to collect active source seismic wave reflection signals. The three-component geophones are connected to the active source demodulator via wired connection to send the active source seismic wave reflection signals to the demodulator, and the relevant results are uploaded to the cloud for joint calculation via data network connection.

4. The method for combined active and passive source geological exploration of shield tunnels as described in claim 1, characterized in that, Passive source sensors are linearly deployed along the tunnel boring machine's direction to collect passive source acoustic wave reflection signals. The passive source sensors are connected to a passive source demodulator via a wired connection to send the passive source acoustic wave reflection signals to the demodulator, and the relevant results are uploaded to the cloud for joint calculation via a data network connection.

5. A combined active and passive source geological exploration system for shield tunnels, characterized in that, include: The acquisition module is configured to acquire active source seismic wave reflection signals and passive source acoustic wave reflection signals; wherein, the active source seismic wave reflection signal is the seismic wave signal excited by the excitation device mounted on the tunnel boring machine after the shield body contacts the surrounding rock; the passive source acoustic wave reflection signal is the acoustic wave signal generated by the shield cutterhead during the tunneling process; The active source detection module is configured to obtain active source geological detection imaging results based on the active source seismic wave reflection signal and the P-wave and S-wave combined imaging principle. The passive source detection module is configured to obtain passive source geological imaging results based on the acoustic wave reflection signals from the passive source using a dispersion extraction-transverse wave velocity inversion method that integrates spatial autocorrelation and a half-wavelength model. The process includes: A time-division Fourier transform is performed on the passive source acoustic wave reflection signal to construct a spatial autocorrelation equation, thereby constructing a dispersion curve model. A half-wavelength model is derived from the half-wave field theory to solve for the transverse wave velocity. Using a detection spatial range and grid partitioning method, and assuming that each grid node is a reflection point, the travel time under the propagation path is obtained based on the positional relationship between the source point, receiver point, and emission point and the given surrounding rock wave velocity. The corresponding instantaneous amplitude value is obtained according to the travel time of the source point and receiver point. The instantaneous amplitudes at the same grid node are superimposed. If the reflection point is the actual interface location, the amplitude will have a maximum value. The joint detection module is configured to primarily use active source geological detection imaging results, supplemented by passive source geological detection imaging results, and combine the adaptive adjustment coefficients between the two to obtain the adverse geological risk level of the area to be measured.

6. A combined active and passive source geological exploration system for shield tunnels, characterized in that, include: The excitation device and three-component geophone mounted on the tunnel boring machine, the passive source sensor deployed along the tunnel boring direction, the active source demodulator connected to the three-component geophone by wire, the passive source demodulator connected to the passive source sensor by wire, and the active and passive source joint computing cloud connected to the active source demodulator and the passive source demodulator by data network. The three-component geophone is used to collect the seismic wave signal generated after the excitation device strikes the shield and contacts the surrounding rock, and sends it to the active source demodulator. The passive source sensor is used to collect the acoustic signals generated by the shield cutterhead during the tunneling process and send them to the passive source demodulator. The active source demodulator is used to obtain active source detection results based on the seismic wave signal using the method described in claim 1; The passive source described herein is used to obtain the passive source detection result based on the acoustic wave signal using the method described in claim 1. The cloud-based joint computing platform for active and passive sources uses the method described in claim 1 to obtain the adverse geological risk level of the area to be tested based on the detection results of the active and passive sources.

7. An electronic device, characterized in that, It includes a memory and a processor, as well as computer instructions stored in the memory and running on the processor, which, when executed by the processor, perform the method of claim 1.

8. A computer-readable storage medium, characterized in that, Used to store computer instructions, which, when executed by a processor, perform the method described in claim 1.

9. A computer program product, characterized in that, It includes a computer program that, when executed by a processor, implements the method of claim 1.

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