Method and system for advanced water exploration using holographic electromagnetic radiation for full-face tunnel boring machine construction

Abstract

The present invention belongs to the technical field of geophysical advance prediction. A method and system for directional holographic induced polarization advance water exploration in full-section tunnel boring machine construction is provided. By obtaining holographic parameters, not only can the relevant information in the induced polarization phenomenon be accurately parameterized, but also can be used to more comprehensively describe the physical characteristics of the rock and soil body; by fully mining and utilizing the rich information in the induced polarization parameters, and combining holographic data with actual rock sampling data, an innovative method is provided for the prediction of the spatial distribution of permeability, and finally the water inflow is predicted based on the results of the permeability prediction; the design is optimized for the specific environmental conditions of the full-section tunnel boring machine, and the power supply electrode and the detection electrode are reasonably mounted on the tunnel boring machine equipment; more reliable geological information support is provided for the construction process of the full-section tunnel boring machine, which can effectively avoid safety accidents caused by sudden water inflow during the construction process.

Description

Technical Field

[0001] The invention relates to the technical field of geophysical advance prediction, and in particular to a method and system for conducting focused holographic induced polarization advance water exploration in full-section tunnel boring machine construction. Background Art

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

[0003] Water inrush disasters are common in tunnel projects, which directly affect the construction progress, cavern stability and personnel safety. Finding out the source of sudden water inrush disasters in front of the tunnel face in advance is the key and inevitable requirement for achieving active disaster prevention.

[0004] The induced polarization method is an electrical detection technology that is based on the accumulation and release of electric charge in the formation. By applying current to the ground and observing the residual potential in the formation after the power is turned off, the electrical difference of the formation is inferred, thereby identifying and locating groundwater bodies. This method is highly sensitive to water bodies and has unique advantages in the detection of water-bearing structures.

[0005] However, the tunnel construction environment of TBM is more complicated than that of traditional drilling and blasting tunnels and ground construction. This is because TBM construction is usually carried out in closed, narrow and deep underground environments, with limited space and complex equipment layout. During the construction process, it faces the influence of many unfavorable factors such as surrounding rock pressure, hydrological environment and operational difficulty. In the actual application of full-section tunnel boring machine tunnel environment, there are still some problems:

[0006] (1) Through the observation data of the entire charge-discharge curve of induced polarization, the zero-frequency resistivity, intrinsic polarization rate, relaxation time and frequency correlation coefficient can be determined by inversion fitting of the Cole-Cole model. However, the four parameters of the Cole-Cole model are only parameterized descriptions of the charge-discharge information, and lack a description of the physical characteristics of the rock mass.

[0007] (2) Tunnels constructed by full-section tunnel boring machines are much more complex than those constructed by drilling and blasting methods or on the ground. First, the tunnel boring machine occupies most of the tunnel space, and the observation space available for advance detection is very limited. Second, the tunnel boring machine has a complex electrical system and metal structure, and electromagnetic interference is extremely serious. The drilling and blasting method and the geophysical detection methods commonly used on the ground cannot be directly applied to tunnels constructed by full-section tunnel boring machines.

[0008] (3) The existing technology for predicting permeability can be roughly divided into two categories: one is to use hydrogeological methods to predict permeability. Since most tunnels are deep tunnels in mountainous canyons, the exploration conditions are extremely incomplete, the information obtained by hydrogeological methods is very limited, and the method is greatly affected by geological structures. The use of this method will introduce large errors. The second is to use the influence of induced polarization parameters on permeability. However, the current technology does not make sufficient use of induced polarization parameters, and the permeability distribution is mostly determined by a single parameter (such as relaxation time). The results are relatively rough and bring large errors. Summary of the invention

[0009] In order to address the shortcomings of the prior art, the present invention provides a method and system for advanced water exploration using directional holographic induced polarization in the construction of a full-section tunnel boring machine. Cole-Cole inversion is performed on the collected data of the entire process to obtain four parameters (zero-frequency resistivity, intrinsic polarizability, relaxation time and frequency correlation coefficient). By introducing normalized polarizability, volumetric water content and cation exchange capacity, more abundant induced polarization holographic data are obtained, and then the permeability is calculated, thereby achieving a more accurate prediction of the amount of water inrush in the tunnel. The present invention can not only quickly and effectively assess the risk of water inrush, but also provide a scientific basis for taking appropriate preventive measures during the construction process, thereby effectively avoiding safety accidents caused by sudden water inrush during the construction process.

[0010] In order to achieve the above object, the present invention adopts the following technical solution:

[0011] In a first aspect, the present invention provides a method for advanced water exploration using holographic induced polarization in full-face tunnel boring machine construction, comprising the following steps:

[0012] By supplying current into the surrounding rock to establish an electric field, the potential data of the tunnel face changing with time is obtained by utilizing the arrangement of the electrode system.

[0013] After removing interference from the potential data, Cole-Cole inversion is performed. Based on the zero-frequency resistivity, intrinsic polarizability, relaxation time and frequency correlation coefficient obtained by the Cole-Cole inversion, the above information is combined with the pore water conductivity, rock particle density and empirical values ​​obtained through experiments collected on site to obtain normalized polarizability, volumetric water content and cation exchange capacity, so that holographic prediction can be performed to obtain permeability prediction results;

[0014] The water inflow is predicted based on the results of permeability prediction.

[0015] As a further limitation of the first aspect of the present invention, removing interference from the potential data includes:

[0016] A first forward modeling result is obtained by forward modeling a tunnel cavity including a full-face tunnel boring machine, and a second forward modeling result is obtained by forward modeling a tunnel cavity not including a full-face tunnel boring machine. The difference between the first forward modeling result and the second forward modeling result is used as the potential interference, and the potential interference is subtracted from all measured potential data.

[0017] As a further limitation of the first aspect of the present invention, the result of permeability prediction is ,in, is the fitting coefficient, is the cation exchange capacity, is saturation, is the porosity, is the first fitting parameter, is the second fitting parameter; represents the particle density, is the weight coefficient, is the relaxation time.

[0018] As a further limitation of the first aspect of the present invention, Water content by volume Calculated, among which, , , is the normalized polarizability, , is the zero-frequency conductivity, is the liquid conductivity, is the ratio of the apparent mobility of the counterion polarization process to the apparent mobility of the surface conduction process, is the Archie cementation index.

[0019] As a further limitation of the first aspect of the present invention, the normalized polarizability ,include: ,in, M is the intrinsic polarizability; Archie cementation index m is: , , The data of bonding index and relaxation time obtained by sampling, is the proportional coefficient obtained through multiple sampling.

[0020] As a further limitation of the first aspect of the present invention, the cation exchange capacity CEC comprises: , represents the apparent mobility of the counter ion during the polarization process.

[0021] As a further limitation of the first aspect of the present invention, the predicted water inflow Q is: ;in, is the surrounding rock permeability coefficient, is the distance from the initial groundwater level to the tunnel floor, is the radius of the equivalent circle of the tunnel cross section, is the equivalent circle diameter of the tunnel cross section, , is the fluid density, is the dynamic viscosity coefficient, is the gravitational acceleration, and k is the permeability prediction result.

[0022] In a second aspect, the present invention provides a holographic electromagnetism advanced water exploration system for full-face tunnel boring machine construction, comprising:

[0023] The host, the power supply electrode system and the measuring electrode system, the cable connection between the host and the power supply electrode system, and the measuring cable connection between the host and the measuring electrode system;

[0024] The host measures the potential data of each measuring point changing with time through the measuring cable of the measuring electrode system, and predicts the water inflow volume based on the obtained potential data using the full-section tunnel boring machine construction focused holographic induced polarization advance water exploration method described in the first aspect of the present invention.

[0025] As a further limitation of the second aspect of the present invention, the power supply electrode system includes two parts, the first part is a fixed power supply cable arranged on the side wall, and the second part is a movable extension cable, and the fixed power supply cable is in parallel with the fixed power supply cable;

[0026] Two fixed power supply cables on the side walls are used for power supply, including: each fixed power supply cable includes multiple power supply A electrodes and one power supply B electrode, the distance between the multiple power supply A electrodes and the tunnel face gradually increases, when in use, the multiple power supply A electrodes and one power supply B electrode are coupled to the corresponding side walls, and the power supply electrodes at the same distance on both sides are powered at the same time, so as to produce the effect of current converging toward the front of the tunnel face;

[0027] The reserved movable extension cable is used for power supply, including: each side wall contains an extension cable, the extension cable is connected to the power supply A electrode, and when in use, the power supply A electrode of the extension cable is coupled to the calibrated power supply point position on the side wall according to the calibrated power supply point position, the power supply B electrode is grounded or connected to the side wall behind the face, the position of the power supply A electrode is continuously moved and data collection is performed until the measurement of all power supply points is completed.

[0028] As a further limitation of the second aspect of the present invention, the measuring electrodes of the measuring electrode system are located on the cutter head, a plurality of measuring electrode arrangement holes are opened in the center block of the cutter head, the connecting wires of the measuring electrodes are gathered into a multi-core cable, and gathered into a quick wiring socket at the center of the cutter head, and the measuring cable is manually connected to the quick wiring socket during measurement, and the other end of the measuring cable is connected to the host;

[0029] All hydraulic cylinders of the cutter disc are arranged in parallel and controlled by a group of solenoid valve blocks. The oil circuits of all cylinders of the cutter disc are aggregated to the central diverter valve block. A hydraulic quick connector needs to be installed on the total oil circuit. When performing induced polarization detection, the oil circuit at the hydraulic valve block is connected to the central diverter valve block of the cutter disc through a quick connector.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] 1. The present invention expands the original four parameters of the Cole-Cole model and adds three new parameters, so that the model can be expanded into holographic data. Through this expansion, the holographic data can not only accurately parameterize the relevant information in the induced polarization phenomenon, but also be used to more comprehensively describe the physical characteristics of the rock and soil. This improvement enhances the model's ability to describe the properties of the rock and soil, and is particularly important in the understanding and application of the induced polarization process. Through the addition of new parameters, the holographic data provides richer details and higher accuracy for the characterization of the complex electrical structure of the rock and soil, thereby helping to improve the accuracy of exploration and analysis.

[0032] 2. The present invention optimizes the design for the specific environmental conditions of TBM, and rationally mounts the measuring electrodes of the measuring electrode system on the TBM equipment, so that in the complex TBM working environment, the data collection process can be faster, more efficient, and easier to operate. This design not only greatly improves the operational flexibility in narrow spaces, but also reduces the extra workload and time when arranging electrodes, ensuring the stability of power supply and signal detection, thereby providing more reliable geological information support for the TBM construction process, and laying a solid technical foundation for safe and efficient tunneling operations.

[0033] 3. The present invention obtains holographic parameters, fully explores and utilizes the rich information in the induced polarization parameters, and combines holographic data with actual rock sampling data to provide an innovative method for predicting the spatial distribution of permeability. Through holographic data, the electrical characteristics of the rock mass can be analyzed from multiple angles, thereby constructing a more accurate permeability distribution model. Compared with the traditional single data source, the holographic parameters used in the present invention can provide a more comprehensive and detailed description of the physical properties of the rock mass, thereby significantly improving the accuracy and reliability of the prediction. Based on the permeability distribution prediction, the present invention further determines the amount of water gushing that may be generated in tunnel excavation or underground engineering.

[0034] Advantages of additional aspects of the present invention will be given in part in the following description, and in part will become obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0036] Figure 1 A schematic diagram of the composition of the power supply electrode system provided by the present invention;

[0037] Figure 2 A schematic diagram of the process of the method for advanced water exploration using holographic induced polarization for full-face tunnel boring machine construction provided by the present invention;

[0038] Figure 3 This is a three-dimensional permeability distribution diagram provided by the present invention. DETAILED DESCRIPTION

[0039] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0040] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0041] This implementation method proposes a method for advanced water exploration using directional holographic induced polarization for full-section tunnel boring machine construction, which is based on a system for advanced water exploration using directional holographic induced polarization for full-section tunnel boring machine construction, including a main unit, a power supply electrode system and a measuring electrode system.

[0042] The host is used for current emission and data collection. The host is connected to the power supply cable of the power supply electrode system, and the current is emitted through the power supply cable by the internal current emission device; the host is connected to the measurement cable of the measurement electrode system to measure the potential information of each measurement point changing with time, thereby completing data collection.

[0043] like Figure 1 As shown, the power supply electrode system can be divided into two parts: one part is a fixed power supply cable arranged on the side wall, and the other part is a movable extension cable. The two parts of the cable are in parallel, and a suitable power supply electrode arrangement scheme can be selected according to needs.

[0044] Solution 1: Two fixed power supply cables on the side wall are used for power supply. This solution can achieve all measurements at one time, and the measurement is relatively convenient and fast. Each fixed power supply cable includes 15 power supply A electrodes and 1 power supply B electrode. The distance between the 15 power supply A electrodes and the face gradually increases, so that the induced polarization information at different distances in front of the face can be obtained. When in use, the 15 power supply A electrodes and the 1 power supply B electrode are coupled to the corresponding side wall, and the power supply electrodes at the same distance on both sides are powered at the same time.

[0045] Solution 2: Use a reserved movable extension cable for power supply. This solution allows the power supply point to be freely determined, and the measurement is relatively flexible. Its power supply B electrode is the same as the power supply B electrode in Solution 1, and is grounded or connected to the side wall at a long distance behind the face. The side walls on both sides each contain an extension cable, which is connected to the power supply A electrode. When using it, first use a tape measure or other tool to measure and calibrate the position of each power supply point, and couple the power supply A electrode of the extension cable to the calibrated power supply point position on the side wall. Keep moving the power supply point position and collect data until all power supply points are measured.

[0046] The measuring electrodes of the measuring electrode system are located on the cutter disc. 14 holes are opened in the center block of the cutter disc. The connecting wires of each electrode are gathered into a multi-core cable and gathered into the quick wiring socket at the center of the cutter disc. When measuring, the main detection cable is manually connected to the quick wiring socket, and the other end of the main detection cable is connected to the main cabinet in the main control room.

[0047] In this implementation, all hydraulic cylinders of the cutter disc are arranged in parallel and controlled by a group of solenoid valve blocks. The oil circuits of all cylinders of the cutter disc are aggregated to the central diverter valve block. A hydraulic quick connector needs to be installed on the total oil circuit. When performing induced polarization detection, the oil circuit at the hydraulic valve block is manually connected to the central diverter valve block of the cutter disc through a quick connector.

[0048] The running electrode method, specifically, takes the fixed cable power supply method as an example: the two cables on the left and right side walls are powered separately, first, the two groups of electrodes A1 and B, A1' and B' are powered at the same time, and the face measurement electrodes measure the potential information changing with time; then the two groups of electrodes A2 and B, A2' and B' are powered at the same time, and the data collection process is repeated; and so on, until 15 groups of electrodes are powered separately and the data collection work is completed.

[0049] Similarly, the power supply method using an extension cable is similar to the above-mentioned running electrode method. It is only necessary to move the power supply A electrode to the corresponding power supply point position in turn and collect data.

[0050] More specifically, Figure 1 In the figure, the five electrodes A1, A2, A3, A4 and A5 are connected to the junction box A through a five-core cable after passing through the junction box J1, the five electrodes A6, A7, A8, A9 and A10 are connected to the junction box A through a five-core cable after passing through the junction box J2, the five electrodes A11, A12, A13, A14 and A15 are connected to the junction box A through a five-core cable after passing through the junction box J3, the junction box A is connected to the exciting polarization host through the 15-core A cable passing through the wallboard, the single-core B cable is connected to the exciting polarization host after passing through the wallboard, the junction box A is connected to the aviation plug through the single-core cable, and the aviation plug is connected to the extension cable (realized by a 180-meter single-core cable reel);

[0051] The five electrodes A1', A2', A3', A4' and A5' are connected to the junction box A' through a five-core cable after passing through the junction box J4, the five electrodes A6', A7', A8', A9' and A10' are connected to the junction box A' through a five-core cable after passing through the junction box J5, the five electrodes A11', A12', A13', A14' and A15' are connected to the junction box A' through a five-core cable after passing through the junction box J6, the junction box A is connected to the exciting polarization host through the 15-core A' cable passing through the wall panel, the single-core B' cable is connected to the exciting polarization host after passing through the wall panel, the junction box A' is connected to the aviation plug through the single-core cable, and the aviation plug is connected to the extension cable (realized by a 180-meter single-core cable reel).

[0052] The proposed method for full-face tunnel boring machine construction with directional holographic induced polarization advance water exploration includes five processes: data acquisition, data interference removal, holographic parameter acquisition (realized by Cole-Cole inversion), permeability distribution prediction and water inflow prediction (realized by combining the values ​​determined in the previous test and the data collected on site for actual application). Figure 2 As shown, including:

[0053] (1) Using the above-mentioned electrode layout and running electrode method to obtain potential information that changes with time, specifically, including:

[0054] Select a fixed power supply cable or a movable extension cable for power supply as needed, and couple the power supply electrode with the tunnel surrounding rock; connect the measuring electrode cable and the oil circuit that controls the extension and retraction of the measuring electrode; turn on the host, set the power supply and receiving parameters, measure the ground resistance and complete the zeroing operation; transmit the current signal, collect the potential information of the measuring electrode over time, and complete the data acquisition operation.

[0055] (2) The responses of the tunnel model with and without a tunnel boring machine are forward calculated, and the interference data generated by the tunnel boring machine is obtained by taking the difference between the two responses. In actual application, the interference data is subtracted from the measured data to obtain the interference-free data.

[0056] The forward modeling of the tunnel cavity containing the TBM is performed and the resulting response is recorded as , which means that when the i-th power supply electrode is powered, the j The potential information at the measuring electrodes is used to perform forward modeling on the tunnel cavity without the TBM machine and the resulting response is recorded as , which means that without TBM, i The potential information at the jth measuring electrode when the jth power supply electrode is powered. It means that when the i-th power supply electrode supplies power, the potential interference caused by the TBM at the j-th measuring electrode is all measured potential data. use Correction, complete the correction of TBM interference.

[0057] (3) In this implementation, Cole-Cole inversion is performed on the collected data of the entire process to obtain four parameters. On this basis, three parameters of the Stern layer model (normalized polarizability, volumetric water content, and cation exchange capacity) are introduced to expand the previous four parameters to seven parameters. On this basis, permeability distribution prediction is performed, providing a feasible way for water volume detection during tunnel construction.

[0058] The original inversion process can be briefly described as follows: the tunnel space model is modeled and the finite element method is used to perform forward simulation to obtain theoretical data. The vector difference between the actual measured data and the theoretical data is used to construct the inversion objective function to obtain the updated value of each parameter, and the clustering algorithm is added to iteratively update the required parameter values.

[0059] The original four parameter inversion adopts the inversion process integrating the clustering algorithm, and its inversion equation is:

[0060] (1);

[0061] In the formula, is the data fitting term, are the balance factors of each parameter, are the model fitting terms of zero-frequency resistivity, intrinsic polarizability, relaxation time and frequency correlation coefficient, respectively. are logarithmic boundary constraints for two model parameters respectively; the last term is the clustering constraint, where C is the number of clusters, H is the total number of grids after the model is discretized, For the j The model parameters of the grid belong to k The membership degree of a cluster, q is the fuzzy coefficient, usually set to 2. For the j The model parameter vector of the grid and Respectively k The inverted cluster center vectors and the reference cluster center vectors of the clusters.

[0062] The above inversion equation is differentiated for the four parameters respectively to obtain the incremental information of the four parameters. The four parameters are continuously updated iteratively until the error reaches the allowable value. It is considered that the parameter value is close to the true value at this time.

[0063] The present invention introduces three new parameters (normalized polarizability, volumetric water content and cation exchange capacity) of the Stern layer model to characterize the physical properties of the rock and soil mass.

[0064] The following equivalent relationship can be obtained from the Stern layer model:

[0065] (2);

[0066] (3);

[0067] (4);

[0068] in, represents the low-frequency conductivity, represents the high frequency conductivity, Indicates the moisture content, represents the particle density, represents the apparent mobility of the counter ion surface conduction process, represents the apparent mobility of the counterion during polarization, represents the cation exchange capacity, is the Archie cementation index.

[0069] There are two ways to determine the normalized polarizability:

[0070] Method 1: , represents the high frequency conductivity, Represents low-frequency conductivity. By measuring the conductivity at high and low frequencies, the normalized polarizability can also be solved. The normalized polarizability represents the difference between the high-frequency and low-frequency conductivity.

[0071] Method 2: ,in represents the low-frequency conductivity, represents the polarizability, which can be determined from the apparent conductivity and apparent polarizability obtained by general inversion.

[0072] By formula as well as , we can get the volume moisture content calculation formula:

[0073] (5);

[0074] in, is the liquid conductivity, It is the ratio of the apparent mobility of the counterion polarization process to the apparent mobility of the surface conduction process. For the same ion type, it is generally considered to be a constant value.

[0075] Cation exchange capacity:

[0076] (6);

[0077] in, is the Archie bonding index, which is determined by the relaxation time in the present invention. m value, represents the particle density, represents the apparent mobility of the counter ion during the polarization process.

[0078] The above three parameters together with the original four parameters constitute the holographic data. Figure 1 The specific process of obtaining holographic data and the relationship diagram of various parameters are given.

[0079] The Cole-Cole inversion of the actual collected data after interference removal can obtain four parameters: , among which, among which, represents the relaxation time, Represents frequency correlation coefficient, zero frequency resistivity Zero frequency conductivity They are reciprocal to each other and can be considered as a parameter.

[0080] Obtaining: Using the zero-frequency resistivity obtained by inversion Intrinsic polarizability , enter the following formula to calculate:

[0081] (7);

[0082] Acquisition: Additional measurement or consultation is required based on the above The value of .

[0083] (8);

[0084] in, , is the liquid conductivity, which needs to be obtained through field experiments. It is the ratio of the apparent mobility of the counterion polarization process to the apparent mobility of the surface conduction process. For the same ion type, it is generally considered to be a certain value and can be obtained by consulting literature.

[0085] is the Archie cementation index. The conventional method generally adopts a fixed value obtained from experience. m Affected greatly by the rock formation, it is impossible to determine its existence using the original method m In the case of a value, only an approximate value can be given based on experience. And all positions in the region use a fixed value, the calculation process is not precise enough, so the original method has a great impact on the accuracy. This implementation method improves it:

[0086] (9);

[0087] , The data of bonding index and relaxation time obtained by sampling, is the proportionality coefficient obtained through multiple sampling. The above formula can be considered as the bonding index m with respect to the relaxation time A function of the holographic parameters The bonding index of each grid can be determined. By using the above formula, the correlation between the bonding index and the relaxation time in the actual environment can be obtained. Using this relationship, combined with the above-obtained holographic parameters , the cementation index can be obtained m Compared with the fixed m value, which can provide more accurate prediction values.

[0088] Acquisition: Take the rock and soil on site and measure its particle density. represents the apparent mobility of the counterion during polarization. In the above solution The value has been obtained by consulting the data and calculated using formula (6).

[0089] It should be noted that all grids in the finite element method modeling process contain a set of holographic data parameter values, so the holographic data can be imaged, which makes it possible to make fuller use of the induced polarization parameters.

[0090] (4) For areas with drastic changes in lithology, since lithology will affect the relationship between relaxation time and cementation index, the corrected cementation index m may have errors, which may cause a significant change in the permeability value, resulting in a large error in the result. In view of this, this implementation method proposes the following permeability calculation method:

[0091] (10);

[0092] in, is a fitting coefficient, which can be obtained by the fitting formula , where is the formation factor, Q is the volume charge density, is saturation, is the porosity, c For The fitting coefficient of the same level can be empirically taken as ; Using the relation Determine the porosity, is the first fitting parameter, is the second fitting parameter, Represents relaxation time.

[0093] To improve accuracy, this implementation adopts a weighted form. The second weighted term is used to represent the influence of relaxation time. A larger proportion of the permeability distribution is determined by the distribution of relaxation time, which reduces the error of the permeability prediction value caused by the drastic change of physical parameters. In actual application, if the lithology changes little, As large as possible (not exceeding 1). If the lithology interface is complex, it is advisable to As small as possible (not less than 0), in other cases, select appropriate parameters based on actual conditions.

[0094] like Figure 3 As shown (showing X, Y, and Z axes, with units in meters), a three-dimensional distribution diagram of permeability in the area is given, and a high permeability area is found within the range of 10m-20m.

[0095] (5) Based on the above holographic parameters and permeability, the water inflow Q is calculated by supplementing the on-site head test and other experiments:

[0096] (11);

[0097] Calculate and obtain water inflow information, where is the maximum water inflow per unit length of the tunnel, is the surrounding rock permeability coefficient, is the distance from the initial groundwater level to the tunnel floor, is the radius of the equivalent circle of the tunnel cross section, is the equivalent circle diameter of the tunnel cross section;

[0098] The formula for converting permeability to permeability coefficient is:

[0099] (12);

[0100] In the formula, is the fluid density, is the dynamic viscosity coefficient, is the acceleration due to gravity.

[0101] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for advanced water exploration using holographic induced polarization in full-face tunnel boring machine construction, characterized in that: The process includes: Obtain the potential data of the side walls on both sides corresponding to the tunnel face that change with time; After removing interference from the potential data, Cole-Cole inversion is performed, and based on the zero-frequency resistivity, intrinsic polarizability, relaxation time and frequency correlation coefficient obtained by the Cole-Cole inversion, a holographic prediction is performed in combination with normalized polarizability, volumetric water content and cation exchange capacity to obtain a permeability prediction result; Predict water inflow based on permeability prediction results; The permeability prediction results are ,in, is the fitting coefficient, is the cation exchange capacity, is saturation, is the porosity, is the first fitting parameter, is the second fitting parameter; represents the particle density, is the weight coefficient, is the relaxation time; Saturation Water content by volume Calculated, among which, , , is the normalized polarizability, , is the zero-frequency conductivity, is the liquid conductivity, is the ratio of the apparent mobility of the counterion polarization process to the apparent mobility of the surface conduction process, is the Archie cementation index; Normalized polarizability ,include: ,in, M is the intrinsic polarizability; Archie cementation index m is: , , The data of bonding index and relaxation time obtained by sampling, is the proportional coefficient obtained through multiple sampling; Cation exchange capacity CEC, including: , represents the apparent mobility of the counter ion during the polarization process; The predicted water inflow Q is: ; in, is the surrounding rock permeability coefficient, is the distance from the initial groundwater level to the tunnel floor, is the radius of the equivalent circle of the tunnel cross section, is the equivalent circle diameter of the tunnel cross section, , is the fluid density, is the dynamic viscosity coefficient, is the gravitational acceleration, and k is the permeability prediction result.

2. The method for advanced water exploration using holographic induced polarization in full-face tunnel boring machine construction as claimed in claim 1, characterized in that: Removing interference from the potential data includes: A first forward modeling result is obtained by forward modeling a tunnel cavity including a full-face tunnel boring machine, and a second forward modeling result is obtained by forward modeling a tunnel cavity not including a full-face tunnel boring machine. The difference between the first forward modeling result and the second forward modeling result is used as the potential interference, and the potential interference is subtracted from all measured potential data.

3. A holographic electromagnetism advanced water exploration system for full-section tunnel boring machine construction, characterized in that: include: The host, the power supply electrode system and the measuring electrode system, the cable connection between the host and the power supply electrode system, and the measuring cable connection between the host and the measuring electrode system; The host measures the potential data of each measuring point changing with time through the measuring cable of the measuring electrode system, and predicts the water inflow volume by using the method of directional holographic induced polarization advance water exploration for full-section tunnel boring machine construction as described in claim 1 or 2 based on the obtained potential data.

4. The full-face tunnel boring machine construction focused holographic IP advance water exploration system as claimed in claim 3, characterized in that: The power supply electrode system includes two parts, the first part is a fixed power supply cable arranged on the side wall, and the second part is a movable extension cable, and the fixed power supply cable is in parallel with the fixed power supply cable; Two fixed power supply cables on the side walls are used for power supply, including: each fixed power supply cable includes multiple power supply A electrodes and one power supply B electrode, the distance between the multiple power supply A electrodes and the tunnel face gradually increases, and when in use, the multiple power supply A electrodes and one power supply B electrode are coupled to the corresponding side walls, and the power supply electrodes at the same distance on both sides are powered at the same time; The reserved movable extension cable is used for power supply, including: each side wall contains an extension cable, the extension cable is connected to the power supply A electrode, and when in use, the power supply A electrode of the extension cable is coupled to the calibrated power supply point position on the side wall according to the calibrated power supply point position, the power supply B electrode is grounded or connected to the side wall behind the face, the position of the power supply A electrode is continuously moved and data collection is performed until the measurement of all power supply points is completed.

5. The full-face tunnel boring machine construction focused holographic induced polarization advanced water exploration system as claimed in claim 4, characterized in that: The measuring electrodes of the measuring electrode system are located on the cutter head. A plurality of measuring electrode arrangement holes are opened in the center block of the cutter head. The connecting wires of the measuring electrodes are gathered into a multi-core cable and gathered into the quick wiring socket at the center of the cutter head. When measuring, the measuring cable is manually connected to the quick wiring socket, and the other end of the measuring cable is connected to the host. All hydraulic cylinders of the cutter disc are arranged in parallel and controlled by a group of solenoid valve blocks. The oil circuits of all cylinders of the cutter disc are aggregated to the central diverter valve block. A hydraulic quick connector needs to be installed on the total oil circuit. When performing induced polarization detection, the oil circuit at the hydraulic valve block is connected to the central diverter valve block of the cutter disc through a quick connector.

Images