Method and system for detecting high temperature water hazard by tunnel induced electric field and temperature field

Abstract

The application provides a tunnel induced electric field and temperature field combined detection high-temperature water disaster method and system, according to the surface exploration data and the high ground temperature monitoring data in the hole, the hydrogeological and ground temperature field conditions of the target area are preliminarily judged, the position and distribution of the possible water-bearing area are determined by using the induced polarization detection, the drilling is carried out outside the possible water-bearing area, the relevant temperature of each place is obtained, the heat source distribution in front of the tunnel is obtained by inversion, and the temperature field distribution is obtained, the induced polarization detection result and the temperature field distribution result are fused, and the determination result of the high-temperature hot water area is obtained. The application fuses two kinds of data of the temperature field and the induced electric field, describes the same heat disaster water body from multiple angles of heat disaster and water body, solves the problem that a single method detection is easy to be affected by interference and multiple solutions are generated, and realizes effective positioning, identification and capture of the high-temperature water disaster.

Description

Technical Field

[0001] This invention belongs to the field of tunnel geothermal field detection technology, and relates to a method and system for jointly detecting high-temperature water hazards by combining tunnel induced electric field and temperature field. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] As tunnel engineering develops towards ultra-deep and ultra-long tunnels, high-temperature heat hazards have become a crucial issue to consider during construction. High-temperature heat hazards in tunnels mainly consist of high rock temperature and high-temperature hot water. High-temperature hot water poses a significant threat to construction safety, not only reducing work efficiency and increasing the risk of heat-related illnesses, but also potentially causing burns and even death. Therefore, during tunnel construction, employing effective measures to identify the location and scale of high-temperature hot water ahead of the tunnel, understanding its temperature and hazard level, and guiding drainage, grouting, and reinforcement procedures can effectively ensure construction safety.

[0004] Currently, methods for detecting high-temperature hot water generally fall into two categories: geological drilling and geophysical exploration. Geological drilling can only detect the geological conditions around the borehole and the temperature inside the borehole. High-temperature hot water in tunnels exists in various forms, and the geological conditions are complex. Geological drilling alone is insufficient to detect the hidden distribution of high-temperature hot water around the borehole, leading to significant underreporting. Among the physical parameters available for detecting high-temperature water hazards in geophysical exploration, the resistivity of the rock mass is the most sensitive. Therefore, electrical resistivity methods are often used for detecting high-temperature water hazards in tunnels. While electrical resistivity methods can detect water-bearing areas ahead of the tunnel, they cannot quantitatively describe the temperature of the hot water, nor can they qualitatively analyze the hazards of high-temperature hot water, making it difficult to effectively guide construction plans. Summary of the Invention

[0005] To address the aforementioned problems, this invention proposes a method and system for jointly detecting high-temperature water hazards using induced electric field and temperature field data in tunnels. This invention integrates temperature field and induced electric field data to characterize the same water body with high temperature hazards from multiple perspectives, including heat hazards and water bodies. It solves the problem of single-method detection being susceptible to interference and producing multiple solutions, and achieves effective location, identification, and capture of high-temperature water hazards. It can identify water-bearing areas, obtain the temperature of hot water, and determine the degree of hazard from hot water, which facilitates guidance for tunnel construction and support treatment.

[0006] According to some embodiments, the present invention adopts the following technical solution:

[0007] A method for jointly detecting high-temperature water hazards using tunnel induced electric field and temperature field includes the following steps:

[0008] Based on surface exploration data and high geothermal monitoring data inside the cave, the hydrogeological and geothermal field conditions of the target area are preliminarily determined.

[0009] Excited polarization detection was used to determine the location and distribution of potential water-bearing regions;

[0010] Drilling is carried out outside the possible water-bearing area to obtain the relevant temperatures at various locations, and the heat source distribution in front of the tunnel is obtained by inversion, and the temperature field distribution is obtained.

[0011] By integrating the results of induced polarization detection and temperature field distribution, the determination result of the high-temperature hot water region is obtained.

[0012] As an alternative implementation method, the specific process of determining the location and distribution of potential water-bearing regions using excited polarization detection includes:

[0013] Based on the actual geological conditions, several measuring electrodes are set up at the working face to form a measuring electrode system, and a power supply electrode is set up at the working face.

[0014] Multiple power supply electrodes are evenly arranged on the tunnel face outline, and a ring of multiple power supply electrodes is arranged at certain intervals on the tunnel sidewall. Two infinity electrodes are arranged on the rear sidewall of the tunnel.

[0015] During face detection, the power supply electrodes on the face contour and the power supply electrode in the middle of the face are supplied with the same current, while the other measuring electrodes collect data.

[0016] Replace the next power supply electrode to provide power, enabling mobile depth sounding;

[0017] The measurement data were preprocessed, and inversion imaging was performed using forward and inverse modeling software. Based on the imaging results, resistivity anomaly regions were analyzed to determine possible water-bearing areas.

[0018] As a further step, the measuring electrodes are arranged in an array and uniformly disposed.

[0019] As a further step, the measuring electrode is a non-polarized electrode, which is set in a downward-sloping borehole on the working face and coupled with salt water to ensure that the electrode is grounded.

[0020] As an alternative implementation, the relevant temperatures at each location include borehole temperature, face rock surface temperature, and sidewall rock surface temperature.

[0021] As a further step, a distributed fiber optic temperature measuring instrument was used to measure the temperature inside the borehole, and an infrared thermometer was used to measure the surface temperature of the tunnel face and the guide wall.

[0022] As an alternative implementation method, the heat source inversion method is a least squares-based heat source inversion method. Combined with the actual geological temperature, inequality constraints are applied, and through continuous iterative inversion, the distribution of high-temperature heat sources is obtained. Through forward modeling, the distribution of the surrounding rock temperature field in front of the tunnel is obtained.

[0023] As an alternative implementation method, the specific process of integrating the induced polarization detection results and the temperature field distribution results is as follows: if the judgment results of the two results are the same, it is determined to be a high-temperature heat source. Through comparative analysis of the heat source and the temperature field, the location of the high-temperature hot water and the level of heat hazard are determined.

[0024] A system for jointly detecting high-temperature water hazards using tunnel induced electric field and temperature field, comprising:

[0025] The preliminary assessment module is used to make a preliminary assessment of the hydrogeological and geothermal field conditions of the target area based on surface exploration data and high geothermal monitoring data inside the cave.

[0026] Excited polarization detection unit is used to determine the location and distribution of possible water-bearing regions using excited polarization detection;

[0027] The temperature field detection unit is used to acquire the temperature inside the borehole outside the possible water-bearing area and the temperature of other areas, invert the heat source distribution in front of the tunnel, and obtain the temperature field distribution.

[0028] The fusion judgment module is used to fuse the excitation polarization detection results and the temperature field distribution results to obtain the judgment result of the high-temperature hot water region.

[0029] As an alternative implementation, it also includes a distributed fiber optic temperature measuring instrument for measuring the temperature inside the borehole, and an infrared thermometer for measuring the surface temperature of the tunnel face and the guide wall.

[0030] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0031] This invention combines the advantages of "temperature field being easy to capture heat source and electric field being sensitive to predict water content" to characterize the same heat-damaged water body from multiple perspectives of "heat hazard" and "water body", thus solving the problem of effectively locating, identifying and capturing high-temperature water hazards.

[0032] This invention overcomes the limitations of a single method. The two methods mutually constrain and verify each other, reducing the ambiguity of a single method and achieving complementary advantages between the two methods to ensure the accuracy of the detection results.

[0033] This invention not only reveals the location and scale of high-temperature water hazards ahead of the tunnel, but also obtains the temperature distribution of the high-temperature hot water, further enhancing the understanding of the hazards of high-temperature hot water. It guides construction personnel to develop effective drainage and grouting reinforcement schemes, effectively ensuring the safety of engineering construction.

[0034] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0035] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0036] Figure 1 This is a flowchart of the operation steps of the detection method of the present invention;

[0037] Figure 2 This is the result of the excited polarization advance detection of the present invention;

[0038] Figure 3 This is a schematic diagram of the borehole temperature measurement setup of the present invention;

[0039] Figure 4 These are the temperature variation curves with depth inside the two boreholes of this invention;

[0040] Figure 5 This is the result of high-temperature heat source detection. Detailed Implementation

[0041] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0042] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0043] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0044] One embodiment of the present invention is a test of combined tunnel induced polarization method and high temperature heat source detection method to detect high temperature hot water in a high geothermal tunnel. The detection method of high temperature hot water is implemented through the following steps:

[0045] Step S1. Construction preparation: Through the analysis of preliminary surface survey data and high geothermal monitoring data inside the tunnel, understand the hydrogeological and geothermal field conditions of the predicted section.

[0046] Surface geological surveys can reveal the geological conditions and rock strata distribution along the tunnel route. Borehole logging can determine the types of thermal hazards (high ground temperature or hot water) that the tunnel may encounter based on the temperature changes with depth within the borehole. Temperature monitoring inside the tunnel can identify temperature variation patterns, whether hot water is exposed, and the type of ground temperature development. Simultaneously, borehole temperature measurement can measure and calculate the thermal conductivity, ground temperature gradient, and heat flux density of the rock, providing prior information for subsequent forward and inverse calculations.

[0047] Step S2. The resistivity distribution ahead of the tunnel is detected using the tunnel-induced polarization method to locate areas of abnormal resistivity and identify potential hot water channels or hot water areas. The instruments used in this embodiment can all be existing technologies. The specific steps are as follows:

[0048] S21. To study the resistivity distribution ahead of the tunnel and locate the high-temperature hot water, three horizontal survey lines, designated as survey lines I, II, and III, were laid out on the tunnel face. Eight electrodes were placed along each survey line, with a spacing of 0.5 m between the electrodes. A power supply electrode was also placed on the tunnel face. During electrode placement, a 5 cm downward-sloping borehole was first drilled on the tunnel face, and a non-polarized electrode was installed. Salt water was injected into the borehole to ensure good coupling between the non-polarized electrode and the surrounding rock. After ensuring good contact between the electrode and the surrounding rock, a wire was connected to the non-polarized electrode, and the electrode was then connected to a cable.

[0049] S22. Four power supply electrodes are evenly distributed on the tunnel face outline. Four power supply electrodes (power supply electrode A) are arranged in a ring at regular intervals on the tunnel sidewall. Two infinity electrodes (measuring electrode N and power supply electrode B) are arranged on the rear sidewall of the tunnel. During face probing, the four power supply electrodes on the face outline and the power supply electrode in the middle of the face are supplied with the same polarity current, while the remaining measuring electrodes collect data. After data collection, the next ring of power supply electrodes is replaced to provide power, achieving mobile depth sounding. The first ring of power supply electrodes is 4m apart from the face, and subsequent rings are spaced 4m apart, for a total of 8 rings.

[0050] S23. Collect data according to the test requirements, import the data into the computer, perform data preprocessing, remove bad points with negative resistivity or abrupt changes, and finally achieve inversion imaging to obtain the resistivity distribution in front of the tunnel, as shown below. Figure 2 As shown. Based on the inversion imaging results, the resistivity anomaly regions in the image are analyzed to preliminarily identify possible hydrothermal areas. Figure 2 It can be seen that there is a low-resistivity area 20-28m ahead of the tunnel, with a resistivity value of less than 595Ω·m.

[0051] Step S3. Based on the resistivity distribution obtained from the induced polarization detection, the location and region of high-temperature hot water are preliminarily inferred. Boreholes are then selected at locations outside the aquifer, and borehole temperature measurements are subsequently conducted. The specific operational steps are as follows:

[0052] S31. Drilling Arrangement: On the left and right sides of the working face, near the sidewalls, drilling rigs are used to drill holes. The borehole diameter and drilling tool specifications are guaranteed to meet the specifications after drilling (error within 1%). The drilling depth reaches 30m. The boreholes reveal no water inside, meeting the requirement of waterless temperature measurement inside the borehole.

[0053] S32. Temperature Measurement Deployment: Distributed temperature measurement optical fibers are deployed into the borehole, then sealed and coupled with cement mortar. The optical fibers are then connected to the temperature measurement host. After a period of time to allow the temperature inside the borehole to equalize with the surrounding rock temperature, borehole temperature data collection is commenced. Figure 3 As shown.

[0054] Step S4. While measuring the borehole temperature, use an infrared thermometer to scan and measure the surface temperature of the left and right sidewalls of the tunnel and the rock face.

[0055] Step S5. After the temperature data is collected, import the data into the computer and analyze the temperature data. Figure 4 The temperature variation curves of the two boreholes with depth reveal the temperature changes ahead of the tunnel. The temperature increases with depth, indicating a closer proximity to high-temperature hot water. Subsequently, the collected borehole temperatures and rock wall surface temperatures are inverted. After heat source inversion imaging, the distribution of high-temperature heat sources is obtained. Through forward modeling, the distribution of the surrounding rock temperature field ahead of the tunnel is obtained, as shown below. Figure 5 As shown in the figure, there is a high-temperature zone 18-30m ahead of the tunnel, with the highest temperature reaching 85℃.

[0056] The heat source distribution is obtained by inversion and then converted into a temperature field distribution. Generally speaking, the temperature field distribution is more familiar and intuitive. It can be seen that the forward modeling of the heat source distribution to obtain the temperature distribution is a forward modeling process, while the inversion modeling of some temperature data to obtain the heat source distribution is an inversion process. Finally, the temperature field distribution is obtained. Of course, the heat source distribution and the temperature field distribution can also be compared and analyzed.

[0057] Step S6. After combined detection using the methods of induced polarization and high-temperature heat source detection, the final conclusion is as follows:

[0058] (1) The results of tunnel induced polarization and high-temperature heat source detection methods both indicate that there is an abnormal area 18-30m in front of the tunnel. The two are very consistent, and it can be inferred that this is a high-temperature hot water area.

[0059] (2) The temperature of the hot water area is as high as 85℃. Combined with its water-rich nature, it poses a great threat to the tunnel. The comprehensive detection results play an important role in guiding the drainage and discharge of hot water, grouting reinforcement and construction optimization.

[0060] The parameters in the above embodiments can be adjusted according to specific circumstances.

[0061] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0062] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A method for jointly detecting high-temperature water hazards using tunnel induced electric field and temperature field, characterized in that, Includes the following steps: Based on surface exploration data and high geothermal monitoring data inside the cave, the hydrogeological and geothermal field conditions of the target area are preliminarily determined. Excited polarization detection was used to determine the location and distribution of potential water-bearing regions; The specific process of determining the location and distribution of potential water-bearing regions using induced polarization detection includes: Based on the actual geological conditions, several measuring electrodes are set up at the working face to form a measuring electrode system, and a power supply electrode is set up at the working face. Multiple power supply electrodes are evenly arranged on the tunnel face outline, and a ring of multiple power supply electrodes is arranged at certain intervals on the tunnel sidewall. Two infinity electrodes are arranged on the rear sidewall of the tunnel. During face detection, the power supply electrodes on the face contour and the power supply electrode in the middle of the face are supplied with the same current, while the other measuring electrodes collect data. Replace the next power supply electrode to provide power, enabling mobile depth sounding; The measurement data is preprocessed, and inversion imaging is performed using forward and inversion software. Based on the imaging results, resistivity anomaly regions are analyzed to determine possible water-bearing regions. Drilling is carried out outside the possible water-bearing area to obtain the relevant temperatures at various locations, and the heat source distribution in front of the tunnel is obtained by inversion, and the temperature field distribution is obtained. Among them, the heat source inversion method is a least squares-based heat source inversion method. Combined with the actual geological temperature, inequality constraints are applied, and through continuous iterative inversion, the distribution of high-temperature heat sources is obtained. Through forward modeling, the distribution of the surrounding rock temperature field in front of the tunnel is obtained. By integrating the results of induced polarization detection and temperature field distribution, the determination result of the high-temperature hot water region is obtained.

2. The method for jointly detecting high-temperature water hazards using tunnel induced electric field and temperature field as described in claim 1, characterized in that, The measuring electrodes are arranged in an array and uniformly disposed.

3. A method for jointly detecting high-temperature water hazards using tunnel induced electric field and temperature field as described in claim 1 or 2, characterized in that, The measuring electrode is a non-polarized electrode, which is set in a downward-sloping borehole on the working face and is grounded by salt water coupling.

4. The method for jointly detecting high-temperature water hazards using tunnel induced electric field and temperature field as described in claim 1, characterized in that, The relevant temperatures at each location include the borehole temperature, the surface temperature of the face rock wall, and the sidewall rock wall temperature.

5. The method for jointly detecting high-temperature water hazards using tunnel induced electric field and temperature field as described in claim 4, characterized in that, Distributed fiber optic temperature measuring instruments were used to measure the temperature inside the borehole, and infrared thermometers were used to measure the surface temperature of the tunnel face and the guide wall.

6. The method for jointly detecting high-temperature water hazards using tunnel induced electric field and temperature field as described in claim 1, characterized in that, The specific process of integrating the results of induced polarization detection and the results of temperature field distribution is as follows: if the judgment results of the two results are the same, it is determined to be a high-temperature heat source. Through comparative analysis of the heat source and the temperature field, the location of the high-temperature hot water and the level of heat hazard are determined.

7. A system for jointly detecting high-temperature water hazards using a tunnel induced electric field and temperature field method as described in any one of claims 1-6, characterized in that, include: The preliminary assessment module is used to make a preliminary assessment of the hydrogeological and geothermal field conditions of the target area based on surface exploration data and high geothermal monitoring data inside the cave. Excited polarization detection unit is used to determine the location and distribution of possible water-bearing regions using excited polarization detection; The temperature field detection unit is used to acquire the temperature inside the borehole outside the possible water-bearing area and the temperature of other areas, invert the heat source distribution in front of the tunnel, and obtain the temperature field distribution. The fusion judgment module is used to fuse the excitation polarization detection results and the temperature field distribution results to obtain the judgment result of the high-temperature hot water region.

8. The system for jointly detecting high-temperature water hazards using tunnel induced electric field and temperature field as described in claim 7, characterized in that, It also includes distributed fiber optic temperature measuring instruments for measuring the temperature inside the borehole, and infrared thermometers for measuring the surface temperature of the tunnel face and the guide wall.

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