Tunnel shield interval boulder prediction and forecast method, medium and equipment

Abstract

The invention discloses a tunnel shield interval boulder prediction method, medium and equipment, and the method comprises the steps: S1, obtaining the high-density electrical method apparent resistivity data of a detection region, and carrying out the inversion to obtain an apparent resistivity two-dimensional profile; s2, integrating the two-dimensional profile into a three-dimensional space, and constructing a continuous three-dimensional resistivity data volume; s3, extracting a threshold value abnormal region according to a preset threshold value A, and determining a boulder suspicious region A; s4, background signal propagation characteristics of the boulder-free area are measured through ultrasonic waves, a threshold value B is set, and if the background signal propagation characteristics exceed the threshold value B in the actual measurement process, the boulder-free area is marked as a boulder suspicious area B; and S5, obtaining an intersection of the abnormal coordinates of the boulder suspicious area A and the boulder suspicious area B, generating a closed three-dimensional boulder suspicious area, and outputting a result in a three-dimensional visualization manner. According to the method, the problems of high false anomaly rate, insufficient spatial information, strong subjective dependence and the like of a traditional single geophysical prospecting method are systematically solved, and the accuracy, the reliability and the engineering applicability of boulder detection are remarkably improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of geological exploration, in particular to a tunnel shield section boulder prediction method, medium and equipment. BACKGROUND

[0002] Boulders are common adverse geological bodies in geological exploration and geotechnical engineering, usually referring to high-strength hard rock bodies occurring in soft soil layers or weathered strata, which can easily cause risks such as abnormal wear of shield cutters and pile deviation in urban subway tunneling, pile foundation construction, etc. Therefore, accurate detection of the spatial distribution of boulders is crucial to engineering safety.

[0003] Existing boulder detection techniques mainly rely on single geophysical methods, such as high-density resistivity method, geological radar or cross-hole CT detection, etc., but these methods have obvious limitations in practical application. The Chinese invention patent with application number 202010547826.5 discloses a subway shield section boulder detection resistivity data fusion three-dimensional imaging method, which carries out geophysical prospecting in the subway shield section, extracts the resistivity data at the same position of the cross-hole resistivity CT and high-density electrical method after inversion of the geophysical prospecting original data, and then uses principal component analysis method to fuse the data at the same position of the two, and converts the two-dimensional coordinates into three-dimensional coordinates through three-dimensional coordinate conversion method after data fusion, so as to better describe the distribution range of boulders in space.

[0004] However, in the above method, the following shortcomings still exist when cross-hole CT and high-density electrical method are fused:

[0005] 1. Relies on intensive drilling, with high cost. Cross-hole CT requires multiple rows of drill holes in the detection area, which has large engineering quantity, high construction cost, and is also limited by site conditions.

[0006] 2. Data fusion relies on principal component analysis, which may lose details. The above scheme fuses the cross-hole CT and high-density electrical method data by principal component analysis, but the principal component analysis aims to maximize variance, which may weaken local abnormal features such as small-size boulders.

[0007] 3. Resolution is limited by drill hole spacing. The resolution of cross-hole CT in the area between drill holes is low, especially near the drill holes, which is prone to imaging blur.

[0008] 4. Weak anti-interference ability. Cross-hole CT and high-density electrical method both rely on resistivity difference, which is easily disturbed by water content, lithology change, etc.

[0009] 5. Three-dimensional modeling relies on interpolation, with limited accuracy. Two-dimensional profiles need to be generated into three-dimensional models by Kriging interpolation, but the sparse cross-hole CT data may cause interpolation errors. SUMMARY

[0010] The tunnel shield interval boulder prediction method, medium and equipment provided by the application have strong anti-interference capability, accurate and reliable detection, and low cost, and can at least solve one of the above technical problems.

[0011] To solve the above technical problems, the application adopts the following technical solutions:

[0012] A tunnel shield interval boulder prediction method comprises the following steps:

[0013] S1, obtaining high-density electrical method apparent resistivity data of a detection area in a tunnel shield interval, and inversely obtaining a two-dimensional profile of apparent resistivity;

[0014] S2, integrating the two-dimensional profile into a three-dimensional space, and constructing a continuous three-dimensional resistivity data body by using an interpolation method;

[0015] S3, extracting a threshold abnormal area according to a preset threshold A, determining a boulder suspicious area A, and extracting coordinates of the boulder suspicious area A;

[0016] S4, measuring background signal propagation characteristics of a boulder-free area by using an ultrasonic wave, setting a threshold B, marking a boulder suspicious area B if the threshold B is exceeded during actual measurement, and determining coordinates of the boulder suspicious area B;

[0017] S5, taking an intersection of abnormal coordinates of the boulder suspicious area A determined by the high-density electrical method and the boulder suspicious area B determined by the ultrasonic wave at the same position, generating a closed three-dimensional boulder suspicious area by using a Kriging interpolation, and outputting a result by three-dimensional visualization.

[0018] Further, in S1, a plurality of high-density electrical method measuring lines are arranged along a central axis of the tunnel shield interval in the detection area to carry out high-density electrical method geophysical prospecting, the plurality of high-density electrical method measuring lines are uniformly spaced and parallel to each other.

[0019] Further, S2 further comprises:

[0020] S2.1, integrating two-dimensional inversion results of the plurality of high-density electrical method measuring lines into a unified three-dimensional space, and setting a fixed coordinate origin in the three-dimensional space;

[0021] S2.2, filling data of a detection area between adjacent high-density electrical method measuring lines based on a Kriging interpolation algorithm, and generating a continuous three-dimensional resistivity data body;

[0022] S2.3, constructing a three-dimensional resistivity model by using three-dimensional visualization software, and generating a three-dimensional data body containing X, Y and Z coordinates and resistivity values.

[0023] Further, in the S3, according to the geological conditions of the detection area, the background resistivity value, i.e. the resistivity range of normal stratum, is analyzed, all the areas with resistivity values higher than a threshold A in the three-dimensional resistivity data body are extracted as abnormal areas, the abnormal areas are three-dimensionally visualized based on three-dimensional visualization software, and the coordinates of the center points and boundaries of the abnormal areas are extracted as the specific positions of the boulder suspicious area A.

[0024] Further, a plurality of drill holes are uniformly arranged along the length direction of the high-density electrical method detection line, and the plurality of drill holes are all opened in the edge or center of the detection area along the vertical direction.

[0025] Further, the S4 further comprises:

[0026] S4.1, each of the plurality of ultrasonic probes is slowly lowered into the corresponding drill hole via the lifting device, and each of the ultrasonic probes comprises a transmitter and a receiver;

[0027] S4.2, the transmitter emits ultrasonic waves in the form of pulses, the receiver records the arrival time and amplitude of the reflected waves, and the suspicious area range of the boulder is preliminarily determined by comparing the threshold B information;

[0028] S4.3, based on the preliminarily determined suspicious area range of the boulder, the position coordinates of the boulder suspicious area B are calculated based on the recorded background signal propagation speed.

[0029] Further, in the S4, the coordinate origin of the output coordinates in the ultrasonic detection operation is the same as the coordinate origin of the output coordinates in the high-density electrical method detection operation.

[0030] Further, in the S5, the intersection of the boulder suspicious area A coordinates and the boulder suspicious area B coordinates is obtained, a three-dimensional coordinate intersection is obtained, a limited number of three-dimensional coordinate points in the three-dimensional coordinate intersection are interpolated into a closed three-dimensional area by using the Kriging interpolation algorithm, a final boulder suspicious area is generated, and a three-dimensional model corresponding to the final boulder suspicious area is drawn by using three-dimensional visualization software.

[0031] A computer readable storage medium stores a computer program, and the computer program is executed by a processor to make the processor execute the steps of the tunnel shield interval boulder prediction and prediction method.

[0032] A computer device comprises a memory and a processor, and the memory stores a computer program, and the computer program is executed by the processor to make the processor execute the steps of the tunnel shield interval boulder prediction and prediction method.

[0033] The beneficial effects of the present application are embodied in:

[0034] The application obtains a three-dimensional space model of boulders in a to-be-detected detection area through multi-source data fusion, three-dimensional modeling and dynamic threshold optimization, can accurately determine the coordinate position of the boulder area, systematically solves the problems of high false anomaly rate, insufficient spatial information and strong subjective dependence of traditional single geophysical prospecting methods, and significantly improves the accuracy, reliability and engineering applicability of boulder detection, thereby providing a more efficient and more accurate geological risk early warning scheme for shield construction. Specifically, the following aspects are also embodied:

[0035] 1. Higher engineering applicability and lower cost

[0036] No need for intensive drilling, suitable for sites with limited construction conditions (such as urban subway), and the ultrasonic equipment is light, only a small amount of drilling or existing drilling is needed for ultrasonic detection, reducing the layout cost, which can be quickly deployed and suitable for large-scale rapid detection.

[0037] 2. Stronger complementarity of multi-source data

[0038] Electrical prospecting can cover a wide range, but is easily disturbed, while ultrasonic prospecting has local high-precision advantages, but the detection range is limited. Therefore, the combination of the two can ensure the detection breadth and improve the positioning accuracy.

[0039] 3. Dynamic threshold optimization reduces subjectivity

[0040] Ultrasonic wave sets threshold value dynamically by measuring the propagation characteristics (such as amplitude and speed) of background signal, avoiding the deviation of artificially set resistivity threshold value, and the result is more objective. The intersection of abnormal coordinates of high-density electrical prospecting and ultrasonic wave is directly taken, and the high-confidence area consistent with both is retained, avoiding the subjectivity of weight distribution.

[0041] 4. Stronger anti-interference ability and higher detection accuracy

[0042] Ultrasonic wave directly identifies hard boulders through wave speed and amplitude threshold value, and clearly identifies the interface of different media (such as the boundary between boulders and surrounding soil) by analyzing the changes of reflected wave and propagation speed, which is less affected by stratum electrical property and has lower false anomaly rate. At the same time, ultrasonic wave can be continuously scanned in the borehole, and the resolution is independent of the detection distance, which can more accurately depict the boulder boundary.

[0043] 5. Real-time and flexibility

[0044] Ultrasonic wave can be detected dynamically with the advancement of shield, and the distribution of boulders is updated in real time, while cross-hole CT needs fixed borehole layout and is difficult to adjust dynamically.

[0045] 6. Three-dimensional visualization is more intuitive

[0046] The closed three-dimensional model is generated by the abnormal coordinate intersection, the single false anomaly of the electrical method or the ultrasonic wave is directly removed, and the model is more reliable. BRIEF DESCRIPTION OF DRAWINGS

[0047] The drawings described herein are used to provide further understanding of the present application, and form a part of the present application. The illustrative embodiments of the present application and their description serve to explain the present application. They do not limit the present application in any form.

[0048] Figure 1 is a whole flowchart of the boulder prediction method of the embodiment of the present application.

[0049] Figure 2 is a schematic diagram of the boulder position in the detection area of the embodiment of the present application.

[0050] Figure 3 is an ultrasonic detection schematic diagram of the embodiment of the present application.

[0051] Figure 4 is a structural block diagram of the computer device of the embodiment of the present application.

[0052] The labels of components in the drawings are as follows: 1, high-density electrical method measuring line; 2, drill hole; 3, ultrasonic probe; 4, boulder; 5, full-face tunnel boring machine (TBM). DETAILED DESCRIPTION

[0053] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all the embodiments. The embodiments in the present application and the features in the embodiments can be combined with each other without conflict. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the present application.

[0054] It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, motion condition, etc. between the components in a certain specific posture (as shown in the drawings), and if the specific posture changes, the directional indications will also change accordingly. In addition, the meaning of "and / or" appearing throughout the text includes three parallel schemes. For example, "A and / or B" includes A scheme, or B scheme, or A and B scheme. In addition, "multiple" means more than two. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the realization of ordinary technical personnel in the art, and when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist and is not within the protection scope required by the present application.

[0055] Referring to Figures 1-2 The embodiments of the present application provide a tunnel shield section boulder prediction method, comprising the following steps:

[0056] S1, obtaining high-density electrical method apparent resistivity data of a detection area in a tunnel shield section, and inversely obtaining a two-dimensional profile of apparent resistivity;

[0057] S2, integrating the two-dimensional profile into a three-dimensional space, and constructing a continuous three-dimensional resistivity data body by using an interpolation method;

[0058] S3, extracting a threshold abnormal area according to a preset threshold A, determining a boulder suspicious area A, and extracting coordinates of the boulder suspicious area A;

[0059] S4, measuring the background signal propagation characteristics of a boulder-free area by using an ultrasonic wave and setting a threshold B, marking a boulder suspicious area B if the threshold B is exceeded during the actual measurement, and determining the coordinates of the boulder suspicious area B;

[0060] S5, taking the intersection of the abnormal coordinates of the boulder suspicious area A determined by the high-density electrical method and the boulder suspicious area B determined by the ultrasonic wave at the same position, generating a closed three-dimensional boulder suspicious area by using a Kriging interpolation, and outputting the result through three-dimensional visualization.

[0061] The Chinese patent "Metro shield section boulder detection resistivity data fusion three-dimensional imaging method" with the application number 202010547826.5 is more suitable for large-scale and deep resistivity structure detection, and its main shortcomings are strong dependence on drilling, limited data fusion algorithm, high cost, and weak anti-interference ability. The method of the present application has advantages in precision, cost, and real-time performance by combining the high resolution, interface recognition, dynamic threshold, and low false anomaly rate of the ultrasonic wave with the large-scale detection capability of the high-density electrical method, and is more suitable for precise early warning of boulders in complex strata. In this way, the combination of ultrasonic wave and geophysical prospecting method further improves the accuracy and reliability of the detection operation.

[0062] Referring to Figure 2 In the embodiment, the S1, along the tunnel shield section axis in the detection area, a plurality of high-density electrical method measuring lines 1 are arranged to carry out high-density electrical method geophysical prospecting. The plurality of high-density electrical method measuring lines 1 are uniformly spaced and parallel to each other.

[0063] Referring to Figures 1-2 In the embodiment, the S2 further comprises:

[0064] S2.1, the two-dimensional inversion results of the plurality of high-density electrical method measuring lines 1 are integrated into a unified three-dimensional space, and a fixed coordinate origin is set in the three-dimensional space;

[0065] S2.2, based on the Kriging interpolation algorithm, the data of the detection area between adjacent high-density electrical method measuring lines 1 is filled to generate a continuous three-dimensional resistivity data body;

[0066] S2.3, a three-dimensional resistivity model is constructed by using three-dimensional visualization software to generate a three-dimensional data body containing X, Y and Z coordinates and resistivity values.

[0067] The apparent resistivity data of each high-density electrical method measuring line 1 is collected, and the data of each high-density electrical method measuring line 1 is two-dimensionally inverted to obtain a two-dimensional distribution profile of underground resistivity.

[0068] The two-dimensional inversion results of the plurality of high-density electrical method measuring lines 1 are integrated into a unified three-dimensional space, and each two-dimensional profile of each measuring line can be regarded as a slice in the three-dimensional space. The two-dimensional inversion result of each measuring line is a two-dimensional profile, which shows the resistivity distribution along the measuring line direction and the depth direction. Therefore, the two-dimensional profiles of the plurality of measuring lines can be combined to construct a three-dimensional space model.

[0069] Therefore, the Kriging interpolation algorithm is used to fill the data of the area between the plurality of measuring lines to generate a continuous three-dimensional resistivity data body, and the Res3Dinv three-dimensional visualization software is used to construct a three-dimensional resistivity model to generate a three-dimensional data body containing X, Y, Z coordinates and resistivity values.

[0070] Referring to Figures 1-2 In the embodiment, the S3, according to the geological conditions of the detection area, the background resistivity value, i.e. the resistivity range of normal stratum, is analyzed, all areas with resistivity values higher than the threshold value A in the three-dimensional resistivity data body are extracted as abnormal areas, and the three-dimensional visualization of the abnormal areas is carried out based on the three-dimensional visualization software. The coordinates of the center point and the boundary of the abnormal area are extracted as the specific position of the suspected rock area A.

[0071] The boulder 4 is usually represented as a high resistivity anomaly, so in the three-dimensional resistivity data body, the area with resistivity values higher than threshold A is extracted as an anomaly area. The anomaly area is visualized by using Res3Dinv three-dimensional visualization software, which can intuitively show the spatial distribution. According to the spatial distribution of the anomaly area, the resistivity isosurface is generated, the area higher than the threshold A is marked as the boulder suspicious area A, and the center point and boundary coordinates (X, Y, Z) of the anomaly area are extracted from the three-dimensional resistivity model as the specific coordinate position of the boulder suspicious area A.

[0072] Referring to Figure 2 In the embodiment, a plurality of drill holes 2 are uniformly and spacedly arranged along the length direction of the high-density electrical method measuring line 1, and the plurality of drill holes 2 are all opened in the edge or center of the detection area along the vertical direction.

[0073] Referring to Figures 2-3 In the embodiment, the S4 further comprises:

[0074] S4.1, slowly lower a plurality of ultrasonic probes 3 into each corresponding drill hole 2 through the lifting device, each ultrasonic probe 3 comprising a transmitter and a receiver;

[0075] S4.2, the transmitter emits ultrasonic waves in the form of pulses, and the receiver records the arrival time and amplitude of the reflected waves, and preliminarily determines the suspicious area range of the boulder 4 by comparing the threshold B information;

[0076] S4.3, on the basis of the preliminarily determined suspicious area range of the boulder 4, the position coordinates of the boulder suspicious area B are calculated by the recorded background signal propagation speed.

[0077] In the detection area, a multi-channel high-frequency transducer is selected, a metal reflector plate is placed in a homogeneous soil layer (such as a boulder-free area) at a known depth, the round-trip time of the ultrasonic wave is measured, and the propagation information of the ultrasonic wave in the boulder-free area soil is obtained. The amplitude and propagation speed of the background signal are recorded, the mean value μ and the standard deviation σ of the background signal are counted, the threshold formula is set, the threshold B = μ + 2σ, and the signals exceeding the threshold B are marked as the boulder suspicious area B.

[0078] Referring to Figures 2-3 In the embodiment, in the S4, the coordinate origin of the output coordinates of the ultrasonic detection operation is the same as the coordinate origin of the output coordinates of the high-density electrical method detection operation.

[0079] Referring to Figure 1 and Figure 3In the embodiment, the S5 is to take intersection of the coordinates of the suspected boulder area A and the coordinates of the suspected boulder area B, obtain three-dimensional coordinate intersection, interpolate the limited three-dimensional coordinate points in the three-dimensional coordinate intersection into a closed three-dimensional area by using the Kriging interpolation algorithm, generate a final suspected boulder area, and draw a three-dimensional model corresponding to the final suspected boulder area by using three-dimensional visualization software.

[0080] It should be noted that the three-dimensional visualization software used in the present application can be Res3Dinv, and the specific software category is not specially limited, and any mature three-dimensional visualization software can be used.

[0081] The embodiment of the present application further provides a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to make the processor execute the steps of the tunnel shield interval boulder prediction method.

[0082] Referring to Figure 4 The embodiment of the present application further provides a computer device, which comprises a memory and a processor, and the memory stores a computer program, and the computer program is executed by the processor to make the processor execute the steps of the tunnel shield interval boulder prediction method.

[0083] The embodiment of the present application further provides a computer program product comprising instructions which, when executed on a computer, cause the computer to perform the steps of the tunnel shield interval boulder prediction method.

[0084] It can be understood that the system, device and storage medium provided by the embodiment of the present application correspond to the method provided by the embodiment of the present application, and the explanation, examples and beneficial effects of the related content can refer to the corresponding part in the tunnel shield interval boulder prediction method.

[0085] It should be understood that all or part of the steps in the embodiments of the present application can be implemented by software, hardware, firmware or any combination thereof. When implemented by hardware, all or part of the steps can be implemented in the form of a purchase standard component or a modification component. When implemented by software, all or part of the steps can be implemented in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of the present application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions can be transmitted from one website, computer, server or data center to another website, computer, server or data center through wired (such as coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (such as infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium accessible by a computer or a data storage device such as a server, data center, etc. integrated with one or more available media. The available media can be a magnetic medium (for example, a floppy disk, a hard disk, a magnetic tape), an optical medium (for example, a DVD), or a semiconductor medium (for example, a solid state disk (SSD)) and the like.

[0086] In summary, to solve the problem of weak anti-interference ability and low precision in the prior art, the present application provides a tunnel shield interval boulder prediction method. First, high-density electrical prospecting work is carried out in the detection area to be detected to obtain high-density electrical resistivity data of the detection area, and the two-dimensional profile of the apparent resistivity is obtained by inversion. Then, the two-dimensional profile is integrated into a three-dimensional space, and an interpolation method is used to construct a continuous three-dimensional resistivity data body. A threshold value is set to extract the threshold abnormal area, determine the boulder suspicious area A and extract the coordinates. Then, the background signal propagation characteristics of the boulder-free area are measured by ultrasonic wave, and a threshold value is set. When the measured value exceeds the threshold value, it is marked as a boulder suspicious area B and the coordinates are determined. Then, the intersection of the abnormal coordinates of the boulder suspicious area A and the boulder suspicious area B is obtained, and a closed three-dimensional boulder suspicious area is generated by Kriging interpolation. Finally, the results are output through three-dimensional visualization. In this way, the limitations of the results under a single detection method are avoided, accurate position coordinates are obtained, and the visibility is improved.

[0087] It should be understood that the examples and embodiments described herein are only for illustration and are not intended to limit the present application. Those skilled in the art can make various modifications or changes based on it, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method for predicting and forecasting isolated boulders in tunnel shield sections, characterized in that, Includes the following steps: S1. Obtain high-density electrical resistivity data of the detection area within the tunnel shield section, and invert to obtain a two-dimensional resistivity profile. S2. Integrate the two-dimensional profile into three-dimensional space and use interpolation to construct a continuous three-dimensional resistivity data volume. S3. Extract the threshold anomaly area based on the preset threshold A, determine the suspicious area A of the isolated rock, and extract the coordinates of the suspicious area A of the isolated rock; S4. Use ultrasonic waves to measure the background signal propagation characteristics of areas without isolated rocks and set a threshold B. If the signal exceeds the threshold B during the actual measurement, it is marked as a suspected isolated rock area B. Determine the coordinates of the suspected isolated rock area B. S5. Take the intersection of the anomaly coordinates of the suspected isolated rock area A determined by high-density electrical resistivity tomography and the suspected isolated rock area B determined by ultrasonic wave at the same location, generate a closed three-dimensional suspected isolated rock area using Kriging interpolation, and output the results through three-dimensional visualization.

2. The method for predicting and forecasting isolated boulders in tunnel shield sections as described in claim 1, characterized in that, In S1, multiple high-density electrical resistivity tomography lines (1) are laid out in the detection area along the central axis of the tunnel shield section to carry out high-density electrical resistivity tomography operations. The multiple high-density electrical resistivity tomography lines (1) are evenly spaced and parallel to each other.

3. The method for predicting and forecasting isolated boulders in tunnel shield sections as described in claim 2, characterized in that, S2 further includes: S2.1 Integrate the two-dimensional inversion results of multiple high-density electrical resistivity tomography lines (1) into a unified three-dimensional space, and set a fixed coordinate origin in the three-dimensional space; S2.

2. Based on the Kriging interpolation algorithm, the detection area between adjacent high-density electrical resistivity survey lines (1) is filled with data to generate a continuous three-dimensional resistivity data volume. S2.3 Utilize 3D visualization software to construct a 3D resistivity model and generate a 3D data volume containing X, Y, and Z coordinates and resistivity values.

4. The method for predicting and forecasting isolated boulders in tunnel shield sections as described in claim 1, characterized in that, In step S3, based on the geological conditions of the detection area, the background resistivity value is analyzed, that is, the resistivity range of the normal strata. All areas with resistivity values ​​higher than the threshold A are extracted from the three-dimensional resistivity data volume as abnormal areas. The abnormal areas are visualized in three dimensions using three-dimensional visualization software. Then, the coordinates of the center point and boundary of the abnormal area are extracted as the specific location of the suspected isolated rock area A.

5. The method for predicting and forecasting isolated boulders in tunnel shield sections as described in claim 1, characterized in that, Multiple boreholes (2) are evenly spaced along the length of the high-density electrical resistivity tomography line (1), and the multiple boreholes (2) are all opened vertically at the edge or center of the detection area.

6. The method for predicting and forecasting isolated boulders in tunnel shield sections as described in claim 5, characterized in that, S4 further includes: S4.

1. Multiple ultrasonic probes (3) are slowly lowered into the corresponding drill holes (2) via a lifting device. Each ultrasonic probe (3) includes a transmitter and a receiver. S4.2 The transmitter emits ultrasonic waves in the form of pulses, and the receiver records the arrival time and amplitude of the reflected waves. By comparing the threshold B information, the suspicious area range of the boulder (4) is initially determined. S4.

3. Based on the preliminarily determined suspicious area of ​​the isolated rock (4), the location coordinates of the suspicious area B of the isolated rock are calculated by the recorded background signal propagation speed.

7. The method for predicting and forecasting isolated boulders in tunnel shield sections as described in claim 6, characterized in that, In S4, the origin of the output coordinates under ultrasonic detection is the same as the origin of the output coordinates under high-density electrical resistivity tomography (EDT) detection.

8. The method for predicting and forecasting isolated boulders in tunnel shield sections as described in claim 1, characterized in that, In step S5, the intersection of the coordinates of the suspected isolated rock area A and the coordinates of the suspected isolated rock area B is obtained to obtain a three-dimensional coordinate intersection. The Kriging interpolation algorithm is used to interpolate a finite number of three-dimensional coordinate points in the three-dimensional coordinate intersection into a closed three-dimensional region to generate the final suspected isolated rock area. The three-dimensional model corresponding to the final suspected isolated rock area is drawn using three-dimensional visualization software.

9. A computer-readable storage medium, characterized in that, The system contains a computer program that, when executed by a processor, causes the processor to perform the steps of the tunnel shield section boulder prediction and forecasting method as described in any one of claims 1-8.

10. A computer device, characterized in that, It includes a memory and a processor, the memory storing a computer program, which, when executed by the processor, causes the processor to perform the steps of the tunnel shield section boulder prediction and forecasting method as described in any one of claims 1-8.

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