Three-dimensional water body space positioning method based on TSP and transient electromagnetic joint inversion

Abstract

The invention relates to the field of tunnel engineering, in particular to a three-dimensional water body space positioning method based on TSP and transient electromagnetic joint inversion. Comprising the following steps: S1, obtaining TSP seismic wave detection data and transient electromagnetic detection data, and respectively carrying out inversion processing to obtain longitudinal wave speed information and resistivity information reflecting physical characteristics of surrounding rocks; s2, carrying out normalization and spatial registration processing on the longitudinal wave speed information and the resistivity information, carrying out data fusion on the two types of information under a unified spatial coordinate system, and generating a three-dimensional data volume representing surrounding rock water yield distribution characteristics; and S3, determining the space boundary of the water-rich body in the underground set according to the distribution characteristics of the three-dimensional data body, and outputting a three-dimensional water body space positioning result. According to the method, the TSP longitudinal wave speed information and the transient electromagnetic resistivity information are fused under the unified space coordinate system, accurate recognition and three-dimensional positioning of underground water-rich body space distribution are achieved, and therefore the accuracy and reliability of tunnel advanced geological forecast are remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of tunnel engineering, and in particular to a three-dimensional spatial positioning method for water bodies based on TSP and transient electromagnetic joint inversion. Background Technology

[0002] With the development of deep-buried and long tunnel projects, the impact of groundwater on construction safety has become increasingly prominent. When tunnels pass through fault zones, fracture zones, or aquifers, they are highly susceptible to disasters such as water inrush and mudslides, seriously threatening construction safety and schedule control. In order to identify potential water-rich areas in a timely manner ahead of construction, advanced geological prediction technologies are usually used to detect the structure and water content of the surrounding rock ahead of the tunnel face. Among them, widely used geophysical exploration methods include the Transient Seismic Wave (TSP) method, the Transient Electromagnetic Transmission (TEM) method, and the Ground Penetrating Radar (GPR) method.

[0003] In existing technologies, TSP (Transient Electromagnetic Probe) technology, by exciting seismic waves and receiving reflected signals, can reflect the differences in P-wave velocities among different rock strata, thereby identifying fractured zones or water-bearing areas. Transient electromagnetic probing (TEM) technology, based on resistivity differences, infers the electrical distribution of surrounding rock by observing the attenuation characteristics of electromagnetic field signals, making it suitable for identifying areas with strong water-bearing potential. However, the identification accuracy of single geophysical methods is limited. TSP technology is sensitive to fractured structures but struggles to accurately reflect the degree of water abundance; TEM can detect low-resistivity water bodies, but is significantly affected by tunnel steel arches and the conductivity of surrounding rock. The two methods reflect different physical quantities, resulting in spatial biases and multiple interpretations in their detection results, easily leading to misjudgments or omissions of water-bearing body locations.

[0004] Currently, the results of TSP (Transient Electromagnetic Probe) and transient electromagnetic (TEM) technologies are mostly interpreted independently, lacking effective joint inversion and data fusion analysis methods, making it difficult to fully leverage the complementary advantages of the two types of geophysical information. Existing methods for identifying the spatial distribution of underground water-rich bodies are mostly based on empirical judgments at the two-dimensional or local level, failing to accurately reflect the spatial range and degree of water abundance. Therefore, how to jointly invert and fuse TSP seismic wave information and transient electromagnetic information under a unified spatial coordinate system to achieve three-dimensional spatial positioning of underground water bodies ahead of tunnels has become a pressing technical problem to be solved in this field. Summary of the Invention

[0005] This application aims to address at least one of the problems existing in current technologies, namely, low accuracy of tunnel geological prediction, multiple interpretations of single geophysical methods, and inability to accurately identify the spatial distribution of underground water-rich bodies. This application provides a three-dimensional spatial location method for water bodies based on combined TSP and transient electromagnetic inversion. This method can comprehensively analyze seismic wave and electromagnetic information under a unified spatial coordinate system to obtain three-dimensional data results reflecting the water-rich distribution characteristics of the surrounding rock. In this method, the P-wave velocity information obtained from TSP seismic wave inversion and the resistivity information obtained from transient electromagnetic inversion are normalized and spatially registered. Through data fusion calculations, a three-dimensional water-rich data volume is generated, enabling the identification and location of the spatial boundaries of concentrated water-rich bodies. This improves the detection accuracy and spatial resolution of underground water-rich bodies ahead of the tunnel, achieving the technical effect of predicting water hazard risks in advance and guiding construction safety.

[0006] In a first aspect, embodiments of this application provide a three-dimensional spatial positioning method for water bodies based on joint inversion of TSP and transient electromagnetic fields. This method may include: S1. Acquire TSP seismic wave detection data and transient electromagnetic detection data, and perform inversion processing respectively to obtain P-wave velocity information and resistivity information reflecting the physical properties of the surrounding rock; S2. The longitudinal wave velocity information and resistivity information are normalized and spatially registered. The two types of information are fused in a unified spatial coordinate system to generate a three-dimensional data volume characterizing the distribution characteristics of water-bearing properties of the surrounding rock. S3. Determine the spatial boundary of the underground concentrated water-rich body based on the distribution characteristics of the three-dimensional data volume, and output the three-dimensional water body spatial positioning result.

[0007] A three-dimensional water body spatial positioning method based on TSP and transient electromagnetic joint inversion according to an embodiment of this application has at least the following beneficial effects: The method of this application first acquires seismic waves and electromagnetic signals using two geophysical methods, TSP and transient electromagnetic methods, respectively, and obtains P-wave velocity and resistivity information through inversion, realizing dual perception of the structural characteristics and water-bearing characteristics of the surrounding rock. Then, by normalizing and spatially registering the two types of information, different physical quantities are fused in a unified coordinate system to construct a three-dimensional data volume reflecting the distribution law of water-bearing properties of the surrounding rock. Subsequently, the spatial boundary of the concentrated water-bearing body is determined according to the distribution characteristics of the three-dimensional data volume, and the three-dimensional water body spatial positioning result is output, realizing accurate identification and visual positioning of the water-bearing area in front of the tunnel face. By jointly analyzing the velocity characteristics obtained from TSP inversion and the resistivity characteristics obtained from transient electromagnetic inversion, the problems of multiple solutions and blurred boundaries of water-rich bodies in single geophysical methods are overcome, and a comprehensive reflection of the spatial distribution of groundwater bodies is achieved. Through data normalization and spatial registration, different geophysical data are spatially consistent, ensuring the reliability and accuracy of the fusion results. By determining the spatial boundaries of the fused three-dimensional data volume, the spatial range and water-rich degree of water-rich bodies can be intuitively presented, thereby significantly improving the spatial resolution and accuracy of tunnel advanced geological prediction, achieving the technical effect of predicting water inrush risks in advance and ensuring the safety of tunnel construction.

[0008] According to some embodiments of this application, the data fusion may include: taking P-wave velocity information and resistivity information as input, establishing a physical model that associates seismic wave parameters and electromagnetic parameters, performing coordinate registration and parameter correspondence processing, and weightedly fusing the two types of information under a unified spatial coordinate system to generate a three-dimensional data volume that reflects the water-bearing distribution characteristics of the surrounding rock.

[0009] According to some embodiments of this application, the data fusion process may further include: taking the surrounding rock grade, lithology, P-wave velocity information and resistivity information as inputs, training the model through a neural network algorithm, calculating the P-wave term weight, resistivity term weight and empirical coefficient, and using the weight parameters to perform weighted processing on the P-wave velocity information and resistivity information to generate a three-dimensional data volume of water-bearing parameters reflecting the water-bearing distribution.

[0010] According to some embodiments of this application, the process of determining the spatial boundary of a concentrated water-rich underground body may include: taking the numerical distribution of a three-dimensional data volume of water-rich parameters as input, performing difference weighting processing based on the maximum and minimum values ​​of the parameter values ​​to determine the boundary conditions of the concentrated water-rich body, and identifying areas where the water-rich parameters are lower than the boundary conditions as concentrated water-rich bodies. According to some embodiments of this application, during tunnel excavation, whenever the tunnel excavation reaches a preset distance, the rock strength is obtained as input, and the boundary of the concentrated water-rich body determined in the previous stage is proportionally corrected to output the dynamically optimized spatial range of the water-rich body.

[0011] According to some embodiments of this application, the three-dimensional water body spatial positioning results are used to guide the design and layout of drainage, support and seepage prevention measures during tunnel excavation.

[0012] Secondly, embodiments of this application provide a three-dimensional water body spatial positioning device based on TSP and transient electromagnetic joint inversion, the device may include: The data acquisition module is used to acquire TSP seismic wave detection data and transient electromagnetic detection data, and perform inversion processing on them respectively to obtain P-wave velocity information and resistivity information reflecting the physical properties of the surrounding rock. The data fusion module is used to normalize and spatially register the P-wave velocity information and resistivity information, and to fuse the P-wave velocity information and resistivity information in a unified spatial coordinate system to generate a three-dimensional data volume characterizing the water-bearing distribution characteristics of the surrounding rock. The spatial positioning module is used to determine the spatial boundary of the underground concentrated water-rich body based on the distribution characteristics of the three-dimensional data volume, and output the three-dimensional water body spatial positioning result.

[0013] The three-dimensional water spatial positioning device based on TSP and transient electromagnetic joint inversion according to the embodiments of this application has at least the following beneficial effects: The three-dimensional water body spatial positioning device based on TSP and transient electromagnetic joint inversion of this application embodiment first acquires TSP seismic wave detection data and transient electromagnetic detection data through the data acquisition module, and obtains P-wave velocity information and resistivity information through inversion processing, ensuring dual perception of surrounding rock structural characteristics and water-bearing characteristics from the source; then, the data fusion module normalizes and spatially registers the two types of information, so that the seismic wave data and electromagnetic data establish a correspondence under a unified coordinate system, and then performs data fusion to generate a three-dimensional data volume reflecting the water-bearing distribution characteristics of the surrounding rock, realizing the comprehensive expression of different physical field data; then, the spatial positioning module determines the spatial boundary of the underground concentrated water-bearing body according to the distribution characteristics of the three-dimensional data volume, and outputs the three-dimensional water body spatial positioning result, realizing accurate identification and spatial visualization of the water-bearing area in front of the tunnel face. The modules are clearly defined in terms of function and data flow, enabling fully automated processing from multi-source geophysical data acquisition to spatial location of water-rich bodies. By completing the joint inversion and fusion analysis of seismic waves and electromagnetic information within the same device, the problems of strong multiple solutions and low spatial matching degree of traditional single geophysical methods are overcome. This significantly improves the accuracy and reliability of water-rich body identification in front of the tunnel, thereby achieving high-resolution positioning of the spatial distribution of groundwater bodies and achieving the technical effect of predicting water hazard risks in advance and ensuring the safety of tunnel construction.

[0014] According to some embodiments of this application, the data acquisition module may include: The seismic wave inversion unit is used to deploy a seismic wave observation system behind the tunnel face, collect TSP seismic wave detection data, and output P-wave velocity information. The electromagnetic inversion unit is used to deploy an electromagnetic observation system at the tunnel face, collect transient electromagnetic detection data, and output resistivity information.

[0015] According to some embodiments of this application, the data fusion module may include: The registration processing unit is used to normalize and spatially register the longitudinal wave velocity information and resistivity information to establish a correspondence under a unified spatial coordinate system. The fusion calculation unit is used to perform weighted fusion of longitudinal wave velocity information and resistivity information based on the correspondence in a unified coordinate system to generate a three-dimensional data volume characterizing the water-bearing distribution characteristics of the surrounding rock.

[0016] Other features and advantages of this application will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing this application. Attached Figure Description

[0017] Figure 1 This is a schematic diagram illustrating the steps of a three-dimensional water body spatial positioning method based on TSP and transient electromagnetic joint inversion according to Embodiment 1 of this application; Figure 2 This is a three-dimensional distribution diagram of the longitudinal wave velocity of the TSP technology in Embodiment 2 of this application; Figure 3 This is a three-dimensional distribution diagram of resistivity data from transient electromagnetic technology in Embodiment 2 of this application; Figure 4 The three-dimensional spatial distribution map of concentrated water-rich bodies was obtained by calculation in Embodiment 2 of this application; Figure 5 This is a structural block diagram of the three-dimensional water body spatial positioning method based on TSP and transient electromagnetic joint inversion in Embodiment 4 of this application. Detailed Implementation

[0018] The present application will now be described in further detail with reference to experimental examples and specific embodiments. However, this should not be construed as limiting the scope of the subject matter of the present application to the following embodiments. All technologies implemented based on the content of the present application fall within the scope of protection of the present application.

[0019] Unless otherwise specified, the terms "upper," "lower," "left," "right," "center," "inner," "outer," and "side" used in the description of specific embodiments of this application to indicate orientation or positional relationships are based on the orientation or positional relationships shown in the accompanying drawings, or the orientation or positional relationship in which the product / equipment / device is usually placed during use. These terms are merely for the purpose of facilitating the description of the solution in this application or simplifying the description in specific embodiments, so as to enable those skilled in the art to quickly understand the solution, and do not indicate or imply that a particular device / component / element must have a specific orientation, or be constructed and operated in a specific positional relationship. Therefore, they should not be construed as limitations on this application.

[0020] In the description of the embodiments of this application, technical terms such as "first" and "second" only distinguish one entity or operation from another, and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary or secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0021] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0022] Example 1 During the research process, the applicant discovered that when using the single TSP seismic wave method or transient electromagnetic method for advanced detection of the surrounding rock ahead of the tunnel face, accurately determining the spatial range and degree of water-rich bodies requires independent inversion and interpretation of different types of geophysical data, followed by manual comparison and analysis to identify anomalous areas. This process is cumbersome, suffers from poor data correlation, and is heavily influenced by empirical judgment, yielding only local two-dimensional results and failing to achieve precise spatial positioning of water-rich bodies. In solving practical engineering problems, to achieve the technical goal of high-precision identification of water-rich areas ahead of the tunnel, existing technologies cannot simultaneously consider the complementary relationship between seismic wave reflection information and electromagnetic response characteristics, nor can they comprehensively analyze multi-source geophysical data under a unified coordinate system, resulting in multiple interpretations and spatial biases in the detection results.

[0023] Therefore, after in-depth research on this problem, the applicant proposed a three-dimensional spatial positioning method for water bodies based on the joint inversion of TSP and transient electromagnetic resistivity. Addressing the technical problem of insufficient accuracy in identifying water-rich bodies ahead of the tunnel, a unified spatial correspondence between TSP longitudinal wave velocity information and transient electromagnetic resistivity information was established. Normalization, registration, and fusion calculations were then performed to achieve the joint inversion and comprehensive expression of the two types of geophysical data. This yields a three-dimensional data volume reflecting the water-rich distribution characteristics of the surrounding rock, thereby determining the spatial boundaries of concentrated water-rich bodies. This technical solution effectively integrates seismic wave and electromagnetic information, significantly improving the spatial resolution and positioning accuracy of water-rich body detection. This enables three-dimensional visualization and positioning of groundwater bodies ahead of the tunnel face, achieving the technical effect of predicting water hazard risks in advance and ensuring tunnel construction safety.

[0024] Please refer to Figure 1 , Figure 1 A schematic diagram illustrating the steps of the three-dimensional water body spatial positioning method based on TSP and transient electromagnetic joint inversion provided in this application embodiment. The three-dimensional water body spatial positioning method based on TSP and transient electromagnetic joint inversion may include: S1. Acquire TSP seismic wave detection data and transient electromagnetic detection data, and perform inversion processing respectively to obtain P-wave velocity information and resistivity information reflecting the physical properties of the surrounding rock; S2. The longitudinal wave velocity information and resistivity information are normalized and spatially registered. The two types of information are fused in a unified spatial coordinate system to generate a three-dimensional data volume characterizing the distribution characteristics of water-bearing properties of the surrounding rock. S3. Determine the spatial boundary of the underground concentrated water-rich body based on the distribution characteristics of the three-dimensional data volume, and output the three-dimensional water body spatial positioning result.

[0025] Specifically, in some implementation schemes, this method is used to identify the spatial distribution of underground water-rich bodies ahead of the tunnel face during tunnel construction, thereby improving the accuracy and reliability of advanced geological prediction. The specific steps are as follows: S1. Acquire TSP seismic wave detection data and transient electromagnetic detection data, and perform inversion processing respectively.

[0026] A seismic wave observation system was deployed behind the tunnel face to collect TSP seismic wave data. After inversion processing, P-wave velocity information reflecting the structural characteristics of the surrounding rock was obtained. Simultaneously, a transient electromagnetic observation system was deployed at the tunnel face to collect transient electromagnetic signals, and resistivity information reflecting the electrical characteristics of the surrounding rock was obtained through inversion processing. This step allows for the acquisition of two types of basic geophysical information describing the integrity and water-bearing capacity of the surrounding rock, providing input data for subsequent fusion analysis.

[0027] S2. The longitudinal wave velocity information and resistivity information are normalized and spatially registered. The two types of information are fused in a unified spatial coordinate system to generate a three-dimensional data volume characterizing the water-bearing distribution characteristics of the surrounding rock.

[0028] Specifically, the P-wave velocity and resistivity information are numerically normalized to ensure consistent data scales for different physical quantities. A correspondence between the P-wave velocity and resistivity information is established under the same spatial coordinates, completing spatial registration. Subsequently, using the registered P-wave velocity and resistivity information as input, a weighted fusion operation is performed to generate a water-bearing three-dimensional data volume, which comprehensively reflects the spatial distribution of the surrounding rock's fracturing degree and water-conducting characteristics.

[0029] S3. Determine the spatial boundary of the underground concentrated water-rich body based on the distribution characteristics of the three-dimensional data volume, and output the three-dimensional water body spatial positioning result.

[0030] The numerical distribution of the water-rich 3D data volume is analyzed. Boundary conditions are determined based on the maximum and minimum values ​​of the water-rich parameters in the data volume. Regions with water-rich parameters below these boundary conditions are identified as concentrated water-rich bodies. This step yields the spatial location, extent, and morphological information of the concentrated water-rich bodies in front of the tunnel face, which is then output in a 3D visualization format, providing a basis for decision-making in subsequent construction.

[0031] Furthermore, during tunnel excavation, whenever the tunnel excavation reaches a preset distance, the rock strength at the tunnel face can be measured. This rock strength is then used as input to proportionally correct the boundary of the concentrated water-rich body determined in the previous stage, thereby outputting the dynamically optimized spatial range of the water-rich body and realizing real-time updating of the water-rich body spatial boundary.

[0032] In geophysical exploration, seismic wave fields and electromagnetic fields reflect the elastic and conductive characteristics of a medium, respectively. While these two types of physical quantities exhibit some spatial continuity, they differ significantly in numerical scale and sensitivity. Different inversion algorithms employ different mathematical models and numerical calculation methods, leading to numerical discrepancies between TSP (Transient Electromagnetic Spinning) inversion results and transient electromagnetic inversion results. To ensure spatial consistency between the two types of inversion results, coupling processing of TSP and transient electromagnetic data is necessary. By establishing a correspondence between P-wave velocity and resistivity information within the same spatial coordinate system, a data transfer channel can be constructed between the seismic wave domain and the electromagnetic domain. Within the corresponding regions, information transfer rules and conversion mechanisms are defined, including determining which physical parameters need to be transferred between the two types of data and how to map the changing characteristics of one physical quantity to a recognizable form of another, thereby ensuring spatial and numerical consistency between inversion results from different physical fields.

[0033] During data fusion, multiple iterative calculations can be performed based on the difference between P-wave velocity and resistivity information, ensuring that the fusion result, after convergence, accurately characterizes the water-bearing distribution features of the surrounding rock. After iteration, the spatial boundaries of concentrated water-bearing bodies can be determined based on the fused three-dimensional data volume, generating three-dimensional water body spatial positioning results, thus achieving precise identification of water-bearing areas ahead of the tunnel face.

[0034] The method provided in this embodiment can integrate the longitudinal wave velocity information obtained from TSP inversion and the resistivity information obtained from transient electromagnetic inversion within a unified spatial coordinate system, comprehensively reflecting the structural integrity and water-bearing characteristics of the surrounding rock. Compared with existing technologies, this embodiment can significantly reduce the ambiguity of single geophysical methods, improve the spatial resolution and positioning accuracy of water-bearing body identification, thereby achieving three-dimensional visualization and positioning of groundwater bodies in front of the tunnel, providing a reliable basis for tunnel construction safety.

[0035] The three-dimensional water body spatial positioning method based on TSP and transient electromagnetic joint inversion provided in this application can be applied to various underground engineering and geological exploration scenarios, such as railway tunnels, highway tunnels, water conservancy diversion tunnels, mine roadways, and underground energy storage projects. In the above implementation, when exploring the surrounding rock in front of the tunnel face in tunnels or underground spaces, a combination of seismic wave excitation and transient electromagnetic excitation can be used to collect signal data reflecting the rock mass structure and water-conducting characteristics. The observation parameters and survey line layout can be automatically adjusted according to different geological conditions to ensure data coverage and detection accuracy. By normalizing, spatially registering, and weighted fusion of the collected data, comprehensive inversion and three-dimensional modeling of different physical field information can be achieved, thereby accurately determining the spatial distribution range and water-rich intensity of underground water-rich bodies. This method can not only identify potential water hazard areas in advance and guide drainage and support design, but also achieve dynamic monitoring and risk warning of water-rich bodies under complex geological conditions, thereby improving the safety of underground engineering construction and the reliability of detection results.

[0036] Example 2 To further illustrate the technical solution of the present invention, this embodiment describes the specific implementation process of the three-dimensional water body spatial positioning method based on TSP and transient electromagnetic joint inversion in conjunction with actual engineering application scenarios.

[0037] Taking the main tunnel of the first tunnel as an example, this tunnel is a crucial control project of the first railway. The tunnel is approximately 20km long and traverses multiple active faults, exhibiting complex lithology, with joints and fissures in some areas of the surrounding rock and abundant groundwater. To accurately identify the spatial distribution of water-rich areas ahead of the tunnel face, the method of this invention was used for on-site testing.

[0038] S1. Data Acquisition and Inversion A TSP (Transient Seismic Spatial Observation System) was deployed approximately 60 m behind the tunnel face to generate seismic wave signals and collect reflected wave data. The three-dimensional spatial data volume of the P-wave velocity of the surrounding rock ahead of the tunnel face was obtained through inversion calculations. The three-dimensional spatial data volume of the P-wave velocity of the surrounding rock ahead of the tunnel face, obtained through inversion calculations, is as follows: Figure 2 As shown, Figure 2 The TSP inversion results for the first tunnel are used to illustrate the velocity distribution characteristics. Test experiments were conducted at the construction site of the first tunnel, with observations carried out within a range of 0–70 meters in front of the tunnel, and the P-wave velocity V in the test section was measured. P The range is 3210m / s to 4980m / s.

[0039] Simultaneously, a transient electromagnetic observation system was deployed at the tunnel face, with five fan-shaped measuring lines set up: 60° upward tilt, 30° upward tilt, horizontal, 30° downward tilt, and 60° downward tilt, each line spaced 15° apart. A square detection antenna (2 m × 2 m) was used to detect transient electromagnetic response signals at the center of the tunnel face. The resistivity of the surrounding rock ahead of the tunnel face was obtained through inversion calculations. The resistivity of the surrounding rock ahead of the tunnel face was obtained through inversion calculations, as shown below. Figure 3 As shown, Figure 3 Showing TEM inversion results for the same section, and... Figure 2 Pairing creates a contrast. The resistivity is measured. Range: 173Ω∙m~829Ω∙m.

[0040] S2. Neural Network Model Training and Parameter Calculation A historical survey database was established, and different surrounding rock grades, lithologies, minimum P-wave velocities, and minimum resistivity values ​​were used as input samples to train a neural network model. The main parameters output by the model include: P-wave term weights. a Resistivity term weight b and empirical coefficient c Using the data from this probe as input, the parameters are obtained after training with a neural network algorithm: a =1.8, b =1.5, c =0.16. This model can automatically adjust the weight allocation under different lithological conditions to ensure a reasonable balance between the relative contributions of TSP and transient electromagnetic data during fusion.

[0041] In this embodiment, the weight of the longitudinal wave term a Weight of resistivity term b and empirical coefficient c The values ​​are obtained through neural network training, and their physical meanings correspond to the structural integrity, electrical characteristics, and water-rich body size of the surrounding rock, respectively. This parameter combination ( a =1.8, b =1.5,c =0.16) is suitable for surrounding rock conditions with well-developed fault zones, dense fissures, and strong water-bearing properties. Higher values... a and b The higher value enhances the model's sensitivity to low-velocity P-waves and low-resistivity regions, allowing the response characteristics of TSP and transient electromagnetic information to be fully reflected during the fusion process; c The value can expand the threshold range for determining water-rich bodies, and better reflect the continuity and spatial expansion characteristics of large-scale water-rich bodies.

[0042] With this parameter combination, the model has higher detection sensitivity and response amplitude in areas with high water content, which can effectively reduce missed detections and achieve accurate characterization of the range and intensity of water-rich bodies.

[0043] S3. Data Normalization and Fusion Computing For the longitudinal wave velocity V P With resistivity Normalization was performed to eliminate dimensional differences in physical quantities. Data registration and fusion were then carried out under a unified spatial coordinate system to obtain a three-dimensional water-bearing parameter data volume reflecting the water-bearing distribution characteristics of the surrounding rock.

[0044] Water-rich parameters The calculation relationship is as follows:

[0045] in, Represents the normalized longitudinal wave velocity. Represents normalized resistivity. a represents the weight of the longitudinal wave term, b represents the weight of the resistivity term; the coefficient 100 is the proportional adjustment coefficient, used to unify the dimensions and scale.

[0046] The calculated three-dimensional data volume of water-bearing parameters is used to comprehensively reflect the degree of fracturing and water-bearing capacity of the surrounding rock in different spatial units.

[0047] S4. Determination of water-rich body boundaries Based on the distribution results of the three-dimensional data volume of water-rich parameters, the maximum value in the data volume is extracted. and minimum value The boundary value of the concentrated water-rich body is calculated using the empirical coefficient c. .

[0048] When the water-bearing parameter of a spatial unit in a three-dimensional data volume Less than this boundary value At that time, the area was determined to be a concentrated water-rich body.

[0049] Based on the distribution results of the three-dimensional data volume of water-rich parameters, the spatial boundary of the concentrated water-rich body is determined, and the three-dimensional spatial distribution results of the concentrated water-rich body are obtained, such as... Figure 4As shown, Figure 4 This demonstrates the final three-dimensional spatial result of the water-rich body obtained after joint inversion and boundary calculation. In this embodiment, the calculated... =397, indicating that there is a concentrated water-rich body in the upper right of the section about 30 to 60 meters ahead of the tunnel, with an abnormal volume of about 1080 m³.

[0050] S5. Dynamic Optimization and Result Verification During tunnel excavation, the rock strength at the tunnel face was measured every 10 meters of tunnel advance. and compared it with the previously measured rock strength. The boundary values ​​of the water-rich body are dynamically adjusted through comparison.

[0051] The corrected relationship is as follows:

[0052] in, This represents the boundary value of the water-rich body after the i-th correction. This represents the boundary value of the previous stage. , This indicates the current rock strength compared to the previous stage.

[0053] Continuous monitoring revealed that the rock strength R fluctuated between 18.2 MPa and 15.5 MPa, with the boundary value showing a gradual increasing trend, indicating that the water-rich area was dynamically optimized. Drilling and drainage measures were implemented approximately 60 meters ahead of the tunnel face, with a total drainage volume of approximately 820 cubic meters, verifying that the water-rich area identified by the method of this invention matched the actual water-rich location.

[0054] Through the specific calculation process provided in this embodiment, the present invention achieves joint inversion and fusion processing of TSP and transient electromagnetic data. P-wave velocity information reflects the integrity of the rock mass structure, while resistivity information characterizes water-bearing properties; fusion of these two data yields a more accurate spatial distribution of water-bearing capacity. Introducing a neural network algorithm to determine weighting coefficients and empirical parameters reduces reliance on manual experience and improves the method's adaptability to different geological conditions. Through boundary value calculation and dynamic correction mechanisms, the spatial range of water-bearing bodies can be updated in real time with the excavation progress, significantly improving the accuracy and real-time performance of tunnel advanced geological prediction.

[0055] In summary, this embodiment verifies the reliability and operability of the method in complex geological environments, and can provide a scientific basis for tunnel construction safety and waterproof design.

[0056] Example 3 To verify the adaptability of the method of the present invention under different geological conditions, this embodiment takes the second tunnel exit section as an example to illustrate the application of the three-dimensional water body spatial positioning method based on TSP and transient electromagnetic joint inversion. The area where the tunnel is located is mainly granite, with a surrounding rock grade of III, relatively well-developed joints and fissures, and relatively weak groundwater but with certain water conductivity.

[0057] S1. Data Acquisition and Inversion A TSP (Transient Seismic Surface Precipitation) observation system was deployed approximately 60 meters behind the second tunnel face to generate seismic wave signals and collect reflection data. The three-dimensional spatial distribution of the P-wave velocity was obtained through inversion processing. The P-wave velocity range in the test section was 4328 m / s to 5216 m / s.

[0058] Simultaneously, a transient electromagnetic observation system was deployed at the working face, with five fan-shaped measuring lines set up: 60° upward tilt, 30° upward tilt, horizontal, 30° downward tilt, and 60° downward tilt. Each measuring line contained nine measuring points, with adjacent measuring points at approximately 15° angles. A square detection antenna (2 meters on each side) was used for signal acquisition, and the three-dimensional spatial distribution information of the surrounding rock resistivity was obtained through inversion processing. The resistivity range of the test section was 311 Ω∙m to 1058 Ω∙m.

[0059] S2. Parameter Calculation and Neural Network Training Based on the existing detection database, the surrounding rock grade, lithology, minimum P-wave velocity, and minimum resistivity are used as input samples. A neural network algorithm is then used for training to obtain the weighted coefficients and empirical coefficients for this detection. a =1.8, b =1.3, c =0.08. This training model achieves the function of automatically optimizing weight allocation under different geological conditions, enabling the data fusion process to adaptively adjust the contribution ratio of physical parameters.

[0060] In this embodiment, the weight of the longitudinal wave term a Weight of resistivity term b and empirical coefficient c The value of is also obtained through a neural network algorithm, and its numerical combination ( a =1.8, b =1.3, c =0.08) is more suitable for geological conditions where the rock mass is relatively intact, the degree of fracture development is low, and the water-rich body is relatively small. In this case, the lower... b The value reduces the influence of resistivity on the model output, allowing P-wave velocity to dominate the fused results, thus highlighting the response to changes in the surrounding rock structure; at the same time, c The lower value narrows the scope of water-rich body identification, enabling the model to more accurately identify local, small-scale water-rich bodies.

[0061] This parameter combination improves the stability and anti-interference capability of the data fusion process, and can maintain high positioning accuracy and result consistency in environments with low water content or low electromagnetic interference.

[0062] S3. Data Fusion and Calculation of Water-Rich Parameters The longitudinal wave velocity information retrieved from TSP and the resistivity information retrieved from transient electromagnetic inversion are normalized and spatially registered respectively, and then weighted and fused in a unified spatial coordinate system.

[0063] Water-rich parameters The calculation relationship is as follows:

[0064] The three-dimensional data volume of water-rich parameters obtained through fusion calculation can comprehensively reflect the structural integrity and water-rich characteristics of the surrounding rock, providing a basis for subsequent boundary identification.

[0065] S4. Determination of water-rich body boundaries Calculate the boundary value of concentrated water-rich bodies =341. Regions with water-rich parameters below this boundary value are identified as concentrated water-rich bodies.

[0066] The results showed that there was a concentrated water-rich body in the middle left direction of the section about 25 to 35 meters in front of the tunnel, with an abnormal volume of about 102 cubic meters.

[0067] S5. Dynamic Optimization and Result Update During tunnel excavation, the rock strength at the tunnel face was measured to vary between 80.6 MPa and 90.2 MPa every 10 meters of excavation. After correction and calculation, the boundary value of the water-rich body changed little, indicating that the water-rich range in this section was relatively stable.

[0068] Through application verification in this embodiment, the proposed method can achieve joint inversion and fusion analysis of TSP and transient electromagnetic data under different surrounding rock conditions. In the geological environment of the second tunnel, the variation characteristics of P-wave velocity and resistivity are clear, and the fused three-dimensional water-rich parameter data volume accurately reflects the water-rich distribution of the surrounding rock. After boundary calculation and dynamic correction, the identified concentrated water-rich areas are basically consistent with the seepage locations during the actual excavation process, verifying the accuracy and applicability of the method. Compared with traditional single geophysical exploration methods, this method has significant improvements in water-rich body identification accuracy, spatial matching degree, and automation level, effectively reducing human interpretation errors and improving the reliability and practicality of tunnel advanced geological prediction.

[0069] Example 4 This embodiment provides a three-dimensional water body spatial positioning device based on TSP and transient electromagnetic joint inversion, used to achieve spatial identification and positioning of water-rich bodies in front of the tunnel face. This device can automatically complete the acquisition, fusion, and three-dimensional positioning analysis of TSP and transient electromagnetic data during tunnel construction or underground exploration.

[0070] like Figure 5 As shown, the device may include: a data acquisition module, a data fusion module, and a spatial positioning module.

[0071] The data acquisition module is used to acquire TSP seismic wave detection data and transient electromagnetic detection data, and then perform inversion processing on them to obtain P-wave velocity and resistivity information reflecting the physical properties of the surrounding rock. This module can characterize the structural integrity and water conductivity of the surrounding rock, providing input data for subsequent fusion calculations.

[0072] The data fusion module is used to normalize and spatially register P-wave velocity and resistivity information. It fuses these two types of information within a unified spatial coordinate system to generate a three-dimensional data volume characterizing the water-bearing properties of the surrounding rock. This module comprehensively reflects the spatial distribution patterns of different physical field parameters, constructing a three-dimensional model that reflects the strength of water-bearing properties.

[0073] The spatial positioning module is used to determine the spatial boundaries of concentrated underground water-rich bodies based on the distribution characteristics of the 3D data volume, and outputs the 3D spatial positioning results of the water bodies. This module can visualize the calculation results to guide construction units in taking appropriate drainage and support measures in front of the tunnel face.

[0074] In one specific implementation, the data acquisition module may include: The seismic wave inversion unit is used to deploy a seismic wave observation system behind the tunnel face, collect TSP seismic wave detection data, and output P-wave velocity information through an inversion algorithm. The electromagnetic inversion unit is used to deploy an electromagnetic observation system at the tunnel face, collect transient electromagnetic detection data, and output resistivity information through an inversion algorithm.

[0075] Through the collaborative work of the aforementioned seismic wave inversion unit and electromagnetic inversion unit, the synchronous acquisition and inversion of seismic wave field and electromagnetic field data can be achieved, laying the foundation for subsequent multi-source data fusion.

[0076] In another implementation, the data fusion module may further include: The registration processing unit is used to normalize and spatially register the longitudinal wave velocity information and resistivity information in order to establish the correspondence between the two types of data under a unified spatial coordinate system. The fusion calculation unit is used to perform weighted fusion of longitudinal wave velocity information and resistivity information based on the correspondence in a unified coordinate system to generate a three-dimensional data volume characterizing the water-bearing distribution characteristics of the surrounding rock.

[0077] Through the collaboration of the above units, the dimensional unification, spatial coordinate alignment and numerical fusion of different physical quantities can be achieved, enabling the device to output accurate and reliable three-dimensional distribution results of water-rich properties.

[0078] The device provided in this embodiment can be connected to a computer processing terminal or a programmable control unit to realize automatic data acquisition, fusion calculation, and three-dimensional display functions. Through modular design, the device can operate independently in an experimental environment or be integrated into a tunnel advanced geological prediction system for real-time monitoring and analysis of the spatial distribution of water-rich bodies ahead, thereby significantly improving the safety and predictive capabilities of underground engineering.

[0079] It should be understood that the positioning of each module of the three-dimensional water spatial positioning device based on TSP and transient electromagnetic joint inversion provided in the above embodiments is only illustrated by the division of each functional module in the above description. In practical applications, the above functions can be assigned to different functional modules as needed. That is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0080] The functional modules in the above embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. Furthermore, the specific names of the functional units and modules are only for easy differentiation and are not intended to limit the scope of protection of the embodiments of this application.

[0081] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects.

[0082] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0083] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A three-dimensional water body spatial positioning method based on TSP and transient electromagnetic joint inversion, characterized in that, The method comprises the following steps: S1. Obtain TSP seismic wave detection data and transient electromagnetic detection data, and perform inversion processing respectively to obtain P-wave velocity information and resistivity information reflecting the physical properties of surrounding rock; S2. Normalize and spatially register the P-wave velocity information and resistivity information, and perform data fusion of the two types of information in a unified spatial coordinate system to generate a three-dimensional data volume representing the distribution characteristics of water enrichment of surrounding rock; S3. Determine the spatial boundary of the underground concentrated water enrichment body according to the distribution characteristics of the three-dimensional data volume, and output the three-dimensional water body spatial positioning result.

2. The method of claim 1, wherein, The TSP seismic wave detection data is obtained by a seismic wave observation system arranged behind the tunnel face, and the P-wave velocity information obtained by inversion calculation is taken as the output; the transient electromagnetic detection data is obtained by an electromagnetic observation system arranged at the tunnel face, and the resistivity information obtained by inversion calculation is taken as the output.

3. The method of claim 1, wherein, The data fusion comprises: taking the P-wave velocity information and the resistivity information as inputs, establishing a physical model associating seismic wave parameters and electromagnetic parameters, performing coordinate registration and parameter correspondence association processing, and performing weighted fusion of the two types of information in a unified spatial coordinate to generate a three-dimensional data volume representing the distribution characteristics of water enrichment of surrounding rock.

4. The method of claim 1, wherein, In the data fusion process, further comprising: taking the surrounding rock grade, lithology, P-wave velocity information and resistivity information as inputs, performing model training by a neural network algorithm, calculating P-wave term weight, resistivity term weight and empirical coefficient, and performing weighted processing on the P-wave velocity information and the resistivity information by using the weight parameters to generate a water enrichment parameter three-dimensional data volume reflecting the distribution of water enrichment.

5. The method of claim 1, wherein, The process of determining the spatial boundary of the underground concentrated water enrichment body comprises: taking the numerical distribution of the water enrichment parameter three-dimensional data volume as input, performing difference weighting processing based on the maximum value and the minimum value of the parameter value to determine the boundary condition of the concentrated water enrichment body, and determining the region with water enrichment parameter lower than the boundary condition as the concentrated water enrichment body.

6. The method of claim 1, wherein, In the tunneling process, whenever the tunnel excavation reaches a preset distance, the rock strength is taken as input to proportionally correct the boundary of the concentrated water enrichment body determined in the previous stage to output the water enrichment body spatial range after dynamic optimization.

7. The method of claim 1, wherein, The three-dimensional water body spatial positioning result is used to guide the design and arrangement of measures including water drainage, support and seepage prevention in the tunneling process.

8. A three-dimensional water body spatial positioning device based on TSP and transient electromagnetic joint inversion, characterized in that, The method comprises the following steps: The data acquisition module is configured to obtain TSP seismic wave detection data and transient electromagnetic detection data, and perform inversion processing respectively to obtain P-wave velocity information and resistivity information reflecting the physical properties of surrounding rock; The data fusion module is configured to normalize and spatially register the P-wave velocity information and resistivity information, and perform data fusion of the P-wave velocity information and the resistivity information in a unified spatial coordinate system to generate a three-dimensional data volume representing the distribution characteristics of water enrichment of surrounding rock; The spatial positioning module is configured to determine the spatial boundary of the underground concentrated water enrichment body according to the distribution characteristics of the three-dimensional data volume, and output the three-dimensional water body spatial positioning result.

9. The apparatus of claim 8, wherein, The data acquisition module comprises: The seismic wave inversion unit is configured to arrange a seismic wave observation system behind the tunnel face, collect TSP seismic wave detection data, and output P-wave velocity information; An electromagnetic inversion unit is arranged to set up an electromagnetic observation system at a tunnel face, collect transient electromagnetic detection data and output resistivity information.

10. The apparatus of claim 8, wherein, The data fusion module comprises: A registration processing unit is configured to normalize and spatially register the P-wave velocity information and the resistivity information to establish a correspondence relationship under a unified spatial coordinate system; A fusion calculation unit is configured to perform weighted fusion of the P-wave velocity information and the resistivity information based on the correspondence relationship under the unified coordinate system to generate a three-dimensional data volume representing the water enrichment distribution characteristics of the surrounding rock.

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