TBM Crossing Adverse Geological Surface-Tunnel Combined Operation Method and System

Abstract

This invention provides a method and system for combined surface-tunnel operation of a TBM traversing adverse geological conditions. The method involves: preliminary geological analysis of the target area; prediction of the location and extent of aquifers using a combined ground-cavity prediction method based on the preliminary analysis results; determination of grouting parameters based on the location and extent of the aquifers; surface grouting of the target area based on the grouting parameters; grouting quality testing; and continued TBM excavation after the grouting quality is deemed satisfactory. Finally, chemical grouting is performed on the water-bearing areas excavated by the TBM to seal the outlets, thus completing the treatment of the aquifer. This invention can provide a treatment range and depth for TBMs traversing shallow-buried water-rich tunnels, thereby improving grouting quality.

Description

Technical Field

[0001] This invention belongs to the field of geological exploration technology, specifically relating to a method and system for combined TBM-tunnel operation across adverse geological surfaces. 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] With the increasing number of tunnel construction projects, more and more tunnel boring machines (TBMs) are being used. However, TBM construction is prone to encountering adverse geological conditions and geological disasters such as sudden water and mud inrushes. This is especially true when small-diameter TBMs pass through shallow, water-rich tunnels, where limited detection and mitigation technologies increase the risk of sudden water inrushes. Inaccurate predictions for small-diameter TBMs can lead to catastrophic consequences, such as tunnel structural damage, equipment failure, project delays, and economic losses including casualties.

[0004] To prevent water inrush disasters in tunnels caused by tunnel boring machines (TBMs), advanced prediction techniques are frequently used to detect water-bearing structures ahead of the tunnel. However, due to the complexity of the TBM construction environment and the extremely complex electromagnetic interference, transient electromagnetic and ground-penetrating radar technologies available in drill-and-blast methods cannot be applied to TBM tunnels. Furthermore, the confined working space prevents the use of large grouting equipment within the tunnel. These problems make it difficult to accurately identify water-bearing structures ahead of the tunnel face in small-diameter TBM tunnels, hindering effective advance treatment of these structures. Therefore, how to more accurately obtain the spatial distribution of water-bearing structures ahead of the tunnel face in small-diameter TBM tunnels and how to manage water-bearing bodies are major challenges that need to be addressed. Summary of the Invention

[0005] To address the aforementioned problems, this invention proposes a combined surface-tunnel operation method and system for TBMs traversing adverse geological conditions. This invention can provide a treatment range and depth for TBMs (especially small-diameter TBMs) traversing shallow-buried water-rich tunnels, thereby improving grouting quality.

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

[0007] A method for combined surface-tunnel operation of TBM traversing adverse geological conditions includes the following steps:

[0008] A preliminary geological analysis of the target area was conducted.

[0009] Based on the preliminary analysis results, the target area was predicted using a combined underground cavern prediction method, and the location and extent of the water-bearing body in the target area were determined based on the prediction results.

[0010] Determine the grouting parameters based on the location and extent of the water-bearing body in the target area;

[0011] Based on the grouting parameters, ground grouting is performed on the target area;

[0012] After the grouting quality is tested and found to be qualified, the TBM will continue tunneling.

[0013] Chemical grouting was performed on the water-bearing area after the TBM excavation to seal the water outlet and complete the treatment of the water-bearing structure.

[0014] As an alternative implementation method, the specific process of conducting a preliminary geological analysis of the target area includes conducting a simple geological background survey of the excavation area before tunnel excavation, analyzing the geological conditions of the area, and roughly judging the water content of the area.

[0015] As an alternative implementation method, the specific process of forecasting the target area using the combined ground-cavity forecasting method includes: performing ground resistivity and tunnel resistivity inversion; using the ground resistivity inversion results to determine the resistivity range of the strata in front of the TBM tunnel, which serves as the initial model for tunnel resistivity inversion; and using the tunnel resistivity inversion results, combined with the water conditions inside the tunnel, to determine the resistivity range of the water-bearing structures.

[0016] As an alternative implementation, the process of performing ground resistivity inversion includes acquiring ground ERT data, performing data inversion on the ground ERT data, and obtaining ERT detection results, i.e., the resistivity range of the target area.

[0017] As an alternative implementation, the least squares method is used to invert the tunnel resistivity data. The resistivity values ​​obtained from the ground resistivity inversion are used as inequality constraints and added to the objective function of the resistivity inversion.

[0018] As a further implementation, the resistivity range obtained from the ground resistivity inversion is introduced as prior information into the inversion equation, and the objective function for inverting resistivity becomes:

[0019] Φ=(Δd-AΔm) T (Δd-AΔm)+λ(CΔm) T (CΔm)

[0020]

[0021] Where A is the sensitivity matrix, m i Here, C is the model parameter, C is the smoothness matrix, Δd is the residual vector between the observed data and the forward modeling theoretical values, Δm is the model parameter increment vector, and λ is the weighting coefficient.

[0022] As an alternative implementation method, the specific process of determining grouting parameters includes: judging the resistivity range of the water-bearing structure based on the location and range of the water-bearing body in the target area and the water conditions in the tunnel, determining the range of the water-bearing structure, and then determining the range and depth of grouting, and selecting grouting materials and processes.

[0023] As an alternative implementation method, the grouting process combines chemical grouting inside the tunnel with surface grouting to stop water.

[0024] As an alternative implementation method, ground grouting is considered qualified when the water conductivity is less than a set value.

[0025] As an alternative implementation method, the outlet is sealed with chemical grouting, and polyurethane grouting material is selected for chemical grouting.

[0026] A combined surface-tunnel operation system for TBMs traversing adverse geological conditions includes:

[0027] The joint forecasting module is used to forecast the target area based on the geology of the target area using a joint forecasting method for caves, and to determine the location and extent of water-bearing bodies in the target area based on the forecasting results;

[0028] The grouting parameter determination module is used to determine the grouting parameters based on the location and extent of the water-bearing body in the target area.

[0029] The operation module is used to perform ground grouting in the target area according to the grouting parameters; to conduct grouting quality testing, and to continue tunneling after the grouting quality is qualified; and to perform chemical grouting in the water-bearing area after the TBM excavation to seal the water outlet and complete the treatment of the water-bearing structure.

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

[0031] 1. This invention solves the problem of difficulty and inaccuracy in advanced geological forecasting when small-diameter TBMs are constructed through shallow tunnels due to the limited tunnel space. By combining ground ERT and tunnel resistivity prediction, the specific location and range of water-bearing structures can be determined.

[0032] 2. This invention solves the problems of limited space, poor sealing effect, low efficiency and poor safety in water inrush treatment of small-diameter TBM tunnels. It determines the location and depth of treatment to achieve more accurate treatment, avoid material waste and reduce treatment time.

[0033] 3. This invention proposes a surface tunnel treatment method for small-diameter tunnels traversing shallow, water-rich tunnels. Surface grouting is used to seal water within the water-bearing structure range and depth defined by the geological exploration method of the surface tunnel. The tunnel outlet is sealed using chemical grouting. This treatment method more effectively avoids the occurrence of water inrush disasters and ensures the safe construction of small-diameter TBMs.

[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 illustrating the process of this embodiment;

[0037] Figure 2 This is a schematic diagram illustrating an example of tunnel resistivity detection in this embodiment;

[0038] Figure 3 This is a schematic diagram of a ground-based ERT detection example in this embodiment;

[0039] Figure 4 This is a schematic diagram of ground grouting in this embodiment;

[0040] Figure 5 This is a schematic diagram of the chemical grouting hole in this embodiment;

[0041] Figure 6 This is a schematic diagram of the chemical grouting hole in this embodiment.

[0042] Among them, 1. Measuring electrode; 2. Tunnel face; 3. Cable; 4. Power supply electrode; 5. Electrical resistivity instrument; 6. Direction of movement of power supply electrode; 7. Ground; 8. Direction of electrode movement; 9. High-density electrical resistivity instrument; 10. Electrode; 11. Cable; 12. Excavation area; 13. Ground grouting body; 14. Ground; 15. Water-bearing structure; 16. Chemical grouting hole; 17. Fissure-shaped water outlet; 18. Chemical grouting hole; 19. Elliptical water outlet. Detailed Implementation

[0043] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0044] 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.

[0045] 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.

[0046] Where there is no conflict, the embodiments and features described in this application may be combined with each other.

[0047] Example 1

[0048] Methods for joint prediction and treatment of small-diameter TBMs crossing adverse geological surfaces and tunnels, such as Figure 1 As shown, the specific process includes the following:

[0049] (1) The geological background of the study area was investigated, and the location and extent of the water-rich structure in the target area were initially understood.

[0050] (2) A combined ground-cavity prediction method for the target area is used to predict the target area. This method includes ground ERT detection and tunnel resistivity testing.

[0051] (3) First, ground ERT detection is carried out to obtain detection data. In this embodiment, RES2D inversion software is used to perform data inversion and obtain ERT detection results. The ground ERT inversion results determine the resistivity range of the strata in front of the small-diameter TBM tunnel. At the same time, it provides an initial model for tunnel resistivity inversion.

[0052] The ERT method combines electrical sounding and electrical profiling. It features a high density of observation points and can detect electrical changes in both horizontal and vertical directions. The detection depth of the ERT method increases with the distance between the power supply and measuring electrodes. As the isolation coefficient gradually increases, the distance between the power supply and measuring electrodes also gradually increases, thus increasing the ability to reflect deep underground media. The electrodes are arranged based on the preliminary location of the aquifer determined by geological analysis.

[0053] (4) Then, tunnel resistivity tests are conducted to obtain detection data. The least squares method is used to invert the tunnel resistivity data. The resistivity values ​​obtained from ground ERT are used as inequality constraints and added to the objective function of resistivity inversion to improve the accuracy of resistivity inversion and obtain more accurate resistivity inversion results.

[0054] Tunnel resistivity detection was conducted, and the resistivity distribution of the target area was obtained by using the ground ERT detection results as inversion constraints.

[0055] (5) Combine the ERT detection results, resistivity inversion results and geological analysis. By combining the tunnel resistivity inversion results with the water conditions in the tunnel, determine the resistivity range of the water-bearing structure, thereby delineating the range of the water-bearing structure, that is, determining the range and depth of the tunnel treatment.

[0056] (6) Determine the grouting parameters, namely the grouting range, grouting depth, grouting material and grouting process, based on the location and range of the water-bearing structure in the target area. That is, water stoppage is achieved by combining chemical grouting inside the tunnel with surface grouting.

[0057] In this embodiment, the drilling equipment used is determined based on the specific depth of the aquifer, and the density of grouting boreholes is selected according to the size of the aquifer. Ground grouting is performed according to the grouting parameters. During ground grouting, the grouting hole area is selected to be approximately 3 meters, and the top of the grouting hole is selected to be approximately 3 meters above the tunnel excavation arch. The curtain is formed through grouting to seal water cracks and prevent sudden water inrush disasters.

[0058] (7) Based on the water-bearing structure area delineated by the geological exploration method of small-diameter ground tunnels, grouting is carried out on the ground using grouting parameters such as the selection of the treatment range and the determination of the treatment depth in front of the tunnel face of small-diameter TBM.

[0059] (8) After the ground grouting is completed, the grouting quality assessment shall be carried out 7 days after the grouting is completed.

[0060] In this embodiment, the number of evaluation holes is no less than 5% of the grouting holes. A water pressure test is used for evaluation. When the water conductivity is less than 10 Lu, the ground grouting is qualified, and the TBM can continue tunneling. If it is greater than 10 Lu, the grouting holes are supplemented with grout before the TBM tunneling continues.

[0061] (9) After the TBM excavation, there were a few water outlets and cracks in the tunnel. The water outlets were sealed with chemical grouting.

[0062] In this embodiment, the chemical grouting material used is polyurethane grouting material, which can quickly cure and seal the water outlet.

[0063] Example 2

[0064] A combined surface-tunnel operation system for TBMs traversing adverse geological conditions includes:

[0065] The joint forecasting module is used to forecast the target area based on the geology of the target area using a joint forecasting method for caves, and to determine the location and extent of water-bearing bodies in the target area based on the forecasting results;

[0066] like Figure 2 , Figure 3 As shown, in this embodiment, the joint forecasting module includes a detection system and an inversion system, both of which include ground components and tunnel components.

[0067] The ground-based detection system includes multiple electrodes 10 arranged sequentially on the ground, which are connected to each other by cables 11. The electrodes 10 are connected to a high-density electrical resistivity tomography (EMT) instrument 9.

[0068] The tunnel detection system includes multiple measuring electrodes 1 installed on the tunnel face 2 and multiple power supply electrodes 4 installed sequentially inside the tunnel. All electrodes are connected to an electrical resistivity instrument 5 via cables 3. The electrodes move inward from the tunnel face.

[0069] The grouting parameter determination module is used to determine the grouting parameters based on the location and extent of the water-bearing body in the target area.

[0070] The operation module is used to perform ground grouting in the target area according to the grouting parameters; to conduct grouting quality testing, and to continue tunneling after the grouting quality is qualified; and to perform chemical grouting in the water-bearing area after the TBM excavation to seal the water outlet and complete the treatment of the water-bearing structure.

[0071] The work module includes the grouting system, such as Figures 4-6 As shown, the grouting system includes multiple ground grouting bodies 13 extending from the ground 14 to the excavation area 12; the grouting area covers the water-bearing structure 15.

[0072] Multiple chemical grouting holes 16 are arranged around the fissure-shaped outlet 17, and the chemical grouting holes 16 are arranged at intervals. Multiple chemical grouting holes 18 are arranged around the circumference of the elliptical outlet 19, and the chemical grouting holes 18 are arranged at intervals.

[0073] 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 by those skilled in the art without creative effort within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A combined surface-tunnel operation method for TBMs traversing adverse geological conditions, characterized in that, Includes the following steps: A preliminary geological analysis of the target area was conducted. Based on the preliminary analysis results, the target area was predicted using a combined underground cavern prediction method, and the location and extent of the water-bearing body in the target area were determined based on the prediction results. Determine the grouting parameters based on the location and extent of the aquifer in the target area; Based on the grouting parameters, ground grouting is performed on the target area; After the grouting quality is tested and found to be qualified, the TBM will continue tunneling. Chemical grouting was carried out on the water-bearing area after the TBM excavation to seal the water outlet and complete the treatment of the water-bearing structure; The specific process of forecasting the target area using the combined method of ground-cavity prediction includes: performing ground resistivity and tunnel resistivity inversion; using the ground resistivity inversion results to determine the resistivity range of the strata in front of the TBM tunnel, which serves as the initial model for tunnel resistivity inversion; and using the tunnel resistivity inversion results, combined with the water conditions inside the tunnel, to determine the resistivity range of the water-bearing structures.

2. The TBM-tunnel combined operation method for traversing adverse geological surfaces as described in claim 1, characterized in that, The specific process of conducting a preliminary geological analysis of the target area includes conducting a simple geological background survey of the excavation area before tunnel excavation, analyzing the geological conditions of the area, and roughly judging the water content of the area.

3. The TBM-tunnel combined operation method for traversing adverse geological surfaces as described in claim 1, characterized in that, The process of performing ground resistivity inversion includes acquiring ground ERT data, performing data inversion on the ground ERT data, and obtaining the ERT detection result, i.e., the resistivity range of the target area.

4. The TBM-tunnel combined operation method for traversing adverse geological surfaces as described in claim 1, characterized in that, The least squares method is used to invert the tunnel resistivity data. The resistivity values ​​obtained from the ground resistivity inversion are used as inequality constraints and added to the objective function of the resistivity inversion.

5. The TBM-tunnel combined operation method for traversing adverse geological surfaces as described in claim 4, characterized in that, By incorporating the resistivity range obtained from the ground resistivity inversion as prior information into the inversion equation, the objective function for resistivity inversion becomes: Where A is the sensitivity matrix, m i Here, C represents the model parameters, and C is the smoothness matrix. The residual vector between the observed data and the forward modeling theoretical values. λ is the increasing vector of model parameters, and λ is the weight coefficient.

6. The TBM surface-tunnel combined operation method for traversing adverse geological conditions as described in claim 1, characterized in that, The specific process of determining grouting parameters includes: based on the location and range of the water-bearing body in the target area, combined with the water conditions in the tunnel, determining the resistivity range of the water-bearing structure, determining the range of the water-bearing structure, and then determining the range and depth of grouting, and selecting grouting materials and processes; Alternatively, the grouting process may combine chemical grouting inside the tunnel with surface grouting to stop water in the tunnel.

7. The TBM-tunnel combined operation method for traversing adverse geological surfaces as described in claim 1, characterized in that, Ground grouting is considered qualified when the water conductivity is less than the set value.

8. The TBM-tunnel combined operation method for traversing adverse geological surfaces as described in claim 1, characterized in that, The outlet was sealed with chemical grouting, and polyurethane grouting material was selected for the chemical grouting.

9. A TBM-tunnel combined operation system for traversing adverse geological surfaces, characterized in that, include: The joint forecasting module is used to forecast the target area based on the geology of the target area using a joint forecasting method for caves, and to determine the location and extent of water-bearing bodies in the target area based on the forecasting results; The grouting parameter determination module is used to determine the grouting parameters based on the location and extent of the water-bearing body in the target area. The operation module is used to perform ground grouting in the target area according to the grouting parameters; to conduct grouting quality testing, and to continue tunneling after the grouting quality is qualified; and to perform chemical grouting in the water-bearing area after the TBM excavation to seal the water outlet and complete the treatment of the water-bearing structure. The specific process of forecasting the target area using the combined method of ground-cavity prediction includes: performing ground resistivity and tunnel resistivity inversion; using the ground resistivity inversion results to determine the resistivity range of the strata in front of the TBM tunnel, which serves as the initial model for tunnel resistivity inversion; and using the tunnel resistivity inversion results, combined with the water conditions inside the tunnel, to determine the resistivity range of the water-bearing structures.

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