A method and system for grading the degree of dolomite sandification in tunnel construction

Abstract

The present invention discloses a method and system for grading the degree of sandification of dolomite during tunnel construction, comprising: obtaining the apparent resistivity and first resistivity of a target section; testing the resistivity of a core sample as a second resistivity, and testing the resistivity of a solid-liquid mixture as a third resistivity; calculating first fracture data and second fracture data; the second fracture data being the distribution of non-through fractures in the core sample; and grading the degree of sandification of the dolomite according to the first fracture data and the second fracture data. The present invention provides a method and system for grading the degree of sandification of dolomite during tunnel construction. Through the above-mentioned technical means, the method and system provide quantitative and intuitive data for on-site judgment of the degree of sandification of dolomite, reducing the judgment error caused by subjective judgment of on-site construction personnel, providing a solid and reliable basis for the formulation of subsequent construction plans, effectively improving construction safety, and providing a reference for the subsequent information-based construction of other sandy dolomite tunnels.

Description

Technical Field

[0001] The present invention relates to intelligent construction technology, and in particular to a method and system for grading the degree of dolomite sandification in tunnel construction. Background Art

[0002] The fine- and microcrystalline dolostones of the granular sandy dolomite formation, belonging to the Dengying Formation (Zbd) of the Upper Sinian System, have developed a network of joints and fissures due to tectonic action. The rock mass fragmentation has created favorable channels and spaces for the storage and migration of groundwater. Simultaneously, the filtration of groundwater and the cyclical effects of dolomitization produce unique dissolution phenomena. Under the influence of continuous surface rainfall, the saturated, dissolve-and-fragment rock mass collapses under the action of osmotic pressure, resulting in water and sand inrush.

[0003] Due to the uneven and discrete distribution of fractures, the sandification degree of dolomite used in tunnel construction also varies. Therefore, adjustments to the sandification degree of dolomite are often necessary during tunnel construction to promptly revise construction plans and ensure safety. However, existing dolomite sandification degree grading methods often rely on qualitative observations by on-site personnel, which is highly subjective. This makes it difficult to accurately formulate subsequent construction plans and can easily lead to construction accidents. Summary of the Invention

[0004] In order to at least overcome the above-mentioned deficiencies in the prior art, the purpose of the present application is to provide a method and system for grading the degree of dolomite sandification in tunnel construction.

[0005] In a first aspect, an embodiment of the present application provides a method for grading the degree of dolomite sandification in tunnel construction, comprising:

[0006] Obtaining the apparent resistivity of the target section by a transient electromagnetic method, and calculating the average resistivity of the target drilling area as a first resistivity based on the apparent resistivity;

[0007] Drilling in the target drilling area to obtain a core sample, testing the resistivity of the core sample as a second resistivity, and testing the resistivity of a solid-liquid mixture in a crack of the core sample as a third resistivity;

[0008] Identifying through-fissures according to the appearance characteristics of the core sample, and calculating first fracture data according to the size of the through-fissures;

[0009] Calculating second fracture data based on the first resistivity, the second resistivity, the third resistivity, and the first fracture data; the second fracture data is the distribution of non-through fractures in the core sample;

[0010] The sandification degree of the dolomite is classified according to the first fracture data and the second fracture data.

[0011] When implementing the embodiment of the present application, the apparent resistivity of the section can be measured according to the transient electromagnetic method and converted into the average resistivity of the target drilling area. It should be understood that the target drilling area should be within the target section, and the target drilling area and the subsequently sampled core sample should correspond to each other; for example, the core sample is sampled with a diameter of 60 cm and a length of 20 meters, then the target drilling area should also use the same size for the calculation of the average resistivity.

[0012] In the embodiments of the present application, after core sampling, the resistivity of the core sample can be tested on-site using an instrument. The resistivity of the solid-liquid mixture in the fractures can also be tested for subsequent calculations. During drilling, the solid-liquid mixture in open fractures will flow out of the fractures after sampling, while the solid-liquid mixture in closed fractures will remain in the fractures for a period of time. The solid-liquid mixture is typically a sand-water mixture. Based on the difference between open and closed fractures, the degree of rock fragmentation can be estimated.

[0013] In the embodiment of the present application, it is necessary to identify the through-fissures, and the identification can be based on manual identification and measurement, or the image recognition of the fissures can be performed by on-site image acquisition. The embodiment of the present application does not impose any restrictions on this. Through the above-mentioned collected relevant data, the data of the closed fissures, that is, the second fissure data, can be calculated, so as to perform the classification of the degree of sandification of the dolomite. The embodiment of the present application provides quantitative and intuitive data for on-site judgment of the degree of sandification of dolomite through the above-mentioned technical means, reduces the judgment error caused by the subjective judgment of on-site construction personnel, provides a solid and reliable basis for the formulation of subsequent construction plans, effectively improves construction safety, and provides a reference for the subsequent information construction of other sandy dolomite tunnels.

[0014] In a possible implementation, calculating the second fracture data according to the first resistivity, the second resistivity, the third resistivity, and the first fracture data includes:

[0015] Inputting the first resistivity and the third resistivity into a preset Archie model to generate a first formula; the water saturation and porosity in the first formula are first unknowns;

[0016] Inputting the second resistivity and the third resistivity into a preset Archie model to generate a second formula; the water saturation and porosity in the second formula are second unknowns;

[0017] Establishing an association relationship between a first unknown number and a second unknown number through the first crack data;

[0018] The first formula, the second formula and the association relationship are combined to calculate the second unknown, and the second crack data is calculated based on the second unknown.

[0019] In one possible implementation, the Archie model is a correspondence between rock resistivity, porosity, resistivity of a solid-liquid mixture in pores, and water saturation;

[0020] Inputting the first resistivity and the third resistivity into a preset Archie model to generate a first formula includes:

[0021] Taking the first resistivity as the rock resistivity and the third resistivity as the resistivity of the solid-liquid mixture in the pores into the Archie model;

[0022] Inputting the second resistivity and the third resistivity into a preset Archie model to generate a second formula includes:

[0023] The second resistivity is taken as the rock resistivity, and the third resistivity is taken as the resistivity of the solid-liquid mixture in the pores and brought into the Archie model.

[0024] In a possible implementation, establishing an association relationship between a first unknown and a second unknown using the first fracture data includes:

[0025] Setting the porosity of the first unknown and the second unknown to be the same as a first association relationship;

[0026] The first fracture data is combined with the water saturation as the discharged water volume data and the change of the water saturation in the second unknown is calculated to form a second correlation relationship;

[0027] The first association relationship and the second association relationship are regarded as the association relationship between the first unknown number and the second unknown number.

[0028] In a possible implementation, identifying through-fractures according to the appearance characteristics of the core sample and calculating first fracture data according to the size of the through-fractures includes:

[0029] Acquiring side images of the core sample in multiple directions under sufficient lighting conditions;

[0030] splicing the side images into a side expanded image of the core sample;

[0031] Through cracks are identified from the side expanded image, and an average value of crack widths of the same through crack is calculated as the first crack data.

[0032] In a second aspect, an embodiment of the present application provides a dolomite sandification degree grading system for tunnel construction, comprising:

[0033] a transient electromagnetic instrument configured to obtain the apparent resistivity of a target section by a transient electromagnetic method;

[0034] a first calculation unit configured to calculate an average resistivity of a target drilling area as a first resistivity based on the apparent resistivity;

[0035] a drilling unit configured to drill in the target drilling area to obtain a core sample;

[0036] a testing unit configured to measure the resistivity of the core sample as a second resistivity and to measure the resistivity of a solid-liquid mixture in fractures of the core sample as a third resistivity;

[0037] an identification unit configured to identify through-going fractures based on appearance characteristics of the core sample;

[0038] a second calculation unit configured to calculate first crack data according to the size of the through crack;

[0039] a third calculation unit configured to calculate second fracture data based on the first resistivity, the second resistivity, the third resistivity, and the first fracture data; the second fracture data is a distribution of non-through fractures in the core sample;

[0040] The classification unit is configured to classify the degree of sandification of the dolomite according to the first fracture data and the second fracture data.

[0041] In a possible implementation, the third computing unit is further configured to:

[0042] Inputting the first resistivity and the third resistivity into a preset Archie model to generate a first formula; the water saturation and porosity in the first formula are first unknowns;

[0043] Inputting the second resistivity and the third resistivity into a preset Archie model to generate a second formula; the water saturation and porosity in the second formula are second unknowns;

[0044] Establishing an association relationship between a first unknown number and a second unknown number through the first crack data;

[0045] The first formula, the second formula and the association relationship are combined to calculate the second unknown, and the second crack data is calculated based on the second unknown.

[0046] In one possible implementation, the Archie model is a correspondence between rock resistivity, porosity, resistivity of a solid-liquid mixture in pores, and water saturation;

[0047] The third computing unit is further configured to

[0048] Taking the first resistivity as the rock resistivity and the third resistivity as the resistivity of the solid-liquid mixture in the pores into the Archie model;

[0049] The second resistivity is taken as the rock resistivity, and the third resistivity is taken as the resistivity of the solid-liquid mixture in the pores and brought into the Archie model.

[0050] In a possible implementation, the third computing unit is further configured to:

[0051] Setting the porosity of the first unknown and the second unknown to be the same as a first association relationship;

[0052] The first fracture data is combined with the water saturation as the discharged water volume data and the change of the water saturation in the second unknown is calculated to form a second correlation relationship;

[0053] The first association relationship and the second association relationship are regarded as the association relationship between the first unknown number and the second unknown number.

[0054] In a possible implementation, the identification unit is further configured to:

[0055] Acquiring side images of the core sample in multiple directions under sufficient lighting conditions;

[0056] splicing the side images into a side expanded image of the core sample;

[0057] Through cracks are identified from the side expanded image, and an average value of crack widths of the same through crack is calculated as the first crack data.

[0058] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0059] The present invention provides a method and system for grading the degree of dolomite sandification during tunnel construction. Through the above-mentioned technical means, the system provides quantitative and intuitive data for on-site judgment of the degree of dolomite sandification, reduces the judgment error caused by the subjective judgment of on-site construction personnel, provides a solid and reliable basis for the formulation of subsequent construction plans, effectively improves construction safety, and provides a reference for the subsequent information-based construction of other sandy dolomite tunnels. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the drawings:

[0061] Figure 1This is a schematic diagram of the method steps of an embodiment of the present application. DETAILED DESCRIPTION

[0062] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. It should be understood that the drawings in the present application only serve the purpose of illustration and description and are not used to limit the scope of protection of the present application. In addition, it should be understood that the schematic drawings are not drawn to scale. The flowcharts used in this application illustrate the operations implemented according to some embodiments of the embodiments of the present application. It should be understood that the operations of the flowcharts can be implemented out of sequence, and steps without logical context can be reversed or implemented simultaneously. In addition, those skilled in the art, under the guidance of the contents of this application, can add one or more other operations to the flowchart, or remove one or more operations from the flowchart.

[0063] In addition, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. The components of the embodiments of the present application generally described and shown in the drawings here can be arranged and designed in various configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed application, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present application.

[0064] Please refer to Figure 1 , which is a flow chart of a method for grading the degree of sandification of dolomite in tunnel construction provided by an embodiment of the present invention. The method for grading the degree of sandification of dolomite in tunnel construction may specifically include the contents described in the following steps S1 to S5.

[0065] S1: Obtaining the apparent resistivity of the target section by a transient electromagnetic method, and calculating the average resistivity of the target drilling area as a first resistivity based on the apparent resistivity;

[0066] S2: Drilling in the target drilling area to obtain a core sample, and testing the resistivity of the core sample as a second resistivity, and testing the resistivity of the solid-liquid mixture in the cracks of the core sample as a third resistivity;

[0067] S3: Identifying through-fissures according to the appearance characteristics of the core sample, and calculating first fracture data according to the size of the through-fissures;

[0068] S4: calculating second fracture data based on the first resistivity, the second resistivity, the third resistivity, and the first fracture data; the second fracture data is the distribution of non-through fractures in the core sample;

[0069] S5: Classifying the degree of sandification of dolomite according to the first fracture data and the second fracture data.

[0070] When implementing the embodiment of the present application, the apparent resistivity of the section can be measured according to the transient electromagnetic method and converted into the average resistivity of the target drilling area. It should be understood that the target drilling area should be within the target section, and the target drilling area and the subsequently sampled core sample should correspond to each other; for example, the core sample is sampled with a diameter of 60 cm and a length of 20 meters, then the target drilling area should also use the same size for the calculation of the average resistivity.

[0071] In the embodiments of the present application, after core sampling, the resistivity of the core sample can be tested on-site using an instrument. The resistivity of the solid-liquid mixture in the fractures can also be tested for subsequent calculations. During drilling, the solid-liquid mixture in open fractures will flow out of the fractures after sampling, while the solid-liquid mixture in closed fractures will remain in the fractures for a period of time. The solid-liquid mixture is typically a sand-water mixture. Based on the difference between open and closed fractures, the degree of rock fragmentation can be estimated.

[0072] In the embodiment of the present application, it is necessary to identify the through-fissures, and the identification can be based on manual identification and measurement, or the image recognition of the fissures can be performed by on-site image acquisition. The embodiment of the present application does not impose any restrictions on this. Through the above-mentioned collected relevant data, the data of the closed fissures, that is, the second fissure data, can be calculated, so as to perform the classification of the degree of sandification of the dolomite. The embodiment of the present application provides quantitative and intuitive data for on-site judgment of the degree of sandification of dolomite through the above-mentioned technical means, reduces the judgment error caused by the subjective judgment of on-site construction personnel, provides a solid and reliable basis for the formulation of subsequent construction plans, effectively improves construction safety, and provides a reference for the subsequent information construction of other sandy dolomite tunnels.

[0073] In a possible implementation, calculating the second fracture data according to the first resistivity, the second resistivity, the third resistivity, and the first fracture data includes:

[0074] Inputting the first resistivity and the third resistivity into a preset Archie model to generate a first formula; the water saturation and porosity in the first formula are first unknowns;

[0075] Inputting the second resistivity and the third resistivity into a preset Archie model to generate a second formula; the water saturation and porosity in the second formula are second unknowns;

[0076] Establishing an association relationship between a first unknown number and a second unknown number through the first crack data;

[0077] The first formula, the second formula and the association relationship are combined to calculate the second unknown, and the second crack data is calculated based on the second unknown.

[0078] When the embodiments of the present application are implemented, the Archie model is an empirical model in the prior art for characterizing the correspondence between parameters such as rock resistivity and porosity, in which some fixed parameters, such as cementation coefficient and proportionality coefficient, can be obtained by pre-measurement. The specific content of the Archie model is not elaborated in detail in the embodiments of the present application. In the use of the Archie model, the inventors found that when calculating the porosity in the Archie model, it is necessary to clarify the water saturation. However, for sandy dolomite, it is difficult to obtain accurate water saturation because the solid-liquid mixture in the cracks will flow out of the cracks during drilling. Based on the above reasons, the embodiments of the present application circumvent this problem by using the Archie model twice.

[0079] In the embodiment of the present application, the first formula generated by the first resistivity and the second resistivity contains two unknowns: water saturation and porosity. Similarly, the second formula also contains two unknowns: water saturation and porosity. For the same target drilling area, the porosity should be the same. Therefore, the relationship between the water saturation in the second formula and the first formula can be calculated using the first fracture data to form a correlation relationship, and the above formula and correlation relationship can be combined to finally complete the calculation. In the embodiment of the present application, the second fracture data can be calculated based on the second unknown by calculating the entire porosity, and then combining the first fracture data to calculate the second fracture data.

[0080] In one possible implementation, the Archie model is a correspondence between rock resistivity, porosity, resistivity of a solid-liquid mixture in pores, and water saturation;

[0081] Inputting the first resistivity and the third resistivity into a preset Archie model to generate a first formula includes:

[0082] Taking the first resistivity as the rock resistivity and the third resistivity as the resistivity of the solid-liquid mixture in the pores into the Archie model;

[0083] Inputting the second resistivity and the third resistivity into a preset Archie model to generate a second formula includes:

[0084] The second resistivity is taken as the rock resistivity, and the third resistivity is taken as the resistivity of the solid-liquid mixture in the pores and brought into the Archie model.

[0085] In a possible implementation, establishing an association relationship between a first unknown and a second unknown using the first fracture data includes:

[0086] Setting the porosity of the first unknown and the second unknown to be the same as a first association relationship;

[0087] The first fracture data is combined with the water saturation as the discharged water volume data and the change of the water saturation in the second unknown is calculated to form a second correlation relationship;

[0088] The first association relationship and the second association relationship are regarded as the association relationship between the first unknown number and the second unknown number.

[0089] When implementing the embodiment of the present application, it is necessary to first determine that the porosity in the first unknown and the second unknown is the same, and then calculate the amount of water discharged in the first fracture data through the first fracture data and the water saturation. It should be understood that the water saturation here is the water saturation in the first unknown, and it is an unknown; the water saturation in the second unknown can be calculated based on the calculated discharged water volume, and the calculation result is to form a functional relationship between the water saturation in the second unknown and the water saturation in the first unknown, and then the porosity is calculated in conjunction with the above-mentioned first formula, second formula and first correlation relationship.

[0090] In a possible implementation, identifying through-fractures according to the appearance characteristics of the core sample and calculating first fracture data according to the size of the through-fractures includes:

[0091] Acquiring side images of the core sample in multiple directions under sufficient lighting conditions;

[0092] splicing the side images into a side expanded image of the core sample;

[0093] Through cracks are identified from the side expanded image, and an average value of crack widths of the same through crack is calculated as the first crack data.

[0094] When implementing the embodiment of the present application, in order to improve the level of intelligence on site, image recognition methods can be used to identify through cracks. Under sufficient lighting conditions, after the side expanded image is grayscaled, the grayscale value of the crack will be significantly higher than that of other areas. Then, edge detection technology is combined to identify through cracks, and the width is calculated to complete the data calculation.

[0095] Based on the same inventive concept, a dolomite sandification degree grading system for tunnel construction is also provided, comprising:

[0096] a transient electromagnetic instrument configured to obtain the apparent resistivity of a target section by a transient electromagnetic method;

[0097] a first calculation unit configured to calculate an average resistivity of a target drilling area as a first resistivity based on the apparent resistivity;

[0098] a drilling unit configured to drill in the target drilling area to obtain a core sample;

[0099] a testing unit configured to measure the resistivity of the core sample as a second resistivity and to measure the resistivity of a solid-liquid mixture in fractures of the core sample as a third resistivity;

[0100] an identification unit configured to identify through-going fractures based on appearance characteristics of the core sample;

[0101] a second calculation unit configured to calculate first crack data according to the size of the through crack;

[0102] a third calculation unit configured to calculate second fracture data based on the first resistivity, the second resistivity, the third resistivity, and the first fracture data; the second fracture data is a distribution of non-through fractures in the core sample;

[0103] The classification unit is configured to classify the degree of sandification of the dolomite according to the first fracture data and the second fracture data.

[0104] In a possible implementation, the third computing unit is further configured to:

[0105] Inputting the first resistivity and the third resistivity into a preset Archie model to generate a first formula; the water saturation and porosity in the first formula are first unknowns;

[0106] Inputting the second resistivity and the third resistivity into a preset Archie model to generate a second formula; the water saturation and porosity in the second formula are second unknowns;

[0107] Establishing an association relationship between a first unknown number and a second unknown number through the first crack data;

[0108] The first formula, the second formula and the association relationship are combined to calculate the second unknown, and the second crack data is calculated based on the second unknown.

[0109] In one possible implementation, the Archie model is a correspondence between rock resistivity, porosity, resistivity of a solid-liquid mixture in pores, and water saturation;

[0110] The third computing unit is further configured to

[0111] Taking the first resistivity as the rock resistivity and the third resistivity as the resistivity of the solid-liquid mixture in the pores into the Archie model;

[0112] The second resistivity is taken as the rock resistivity, and the third resistivity is taken as the resistivity of the solid-liquid mixture in the pores and brought into the Archie model.

[0113] In a possible implementation, the third computing unit is further configured to:

[0114] Setting the porosity of the first unknown and the second unknown to be the same as a first association relationship;

[0115] The first fracture data is combined with the water saturation as the discharged water volume data and the change of the water saturation in the second unknown is calculated to form a second correlation relationship;

[0116] The first association relationship and the second association relationship are regarded as the association relationship between the first unknown number and the second unknown number.

[0117] In a possible implementation, the identification unit is further configured to:

[0118] Acquiring side images of the core sample in multiple directions under sufficient lighting conditions;

[0119] splicing the side images into a side expanded image of the core sample;

[0120] Through cracks are identified from the side expanded image, and an average value of crack widths of the same through crack is calculated as the first crack data.

[0121] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the above description has generally described the composition and steps of each example according to function. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0122] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, or can be electrical, mechanical or other forms of connection.

[0123] The units described as separate components may or may not be physically separated. As units, it is obvious that a person of ordinary skill in the art can realize that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in terms of function in the above description. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0124] In addition, the functional units in the various embodiments of the present invention may be integrated into a single processing unit, each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0125] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, server, or grid device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: various media that can store program code, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0126] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for grading the degree of sandification of dolomite in tunnel construction, characterized in that: include: Obtaining the apparent resistivity of the target section by a transient electromagnetic method, and calculating the average resistivity of the target drilling area as a first resistivity based on the apparent resistivity; Drilling in the target drilling area to obtain a core sample, testing the resistivity of the core sample as a second resistivity, and testing the resistivity of a solid-liquid mixture in a crack of the core sample as a third resistivity; Identifying through-fissures according to the appearance characteristics of the core sample, and calculating first fracture data according to the size of the through-fissures; Calculating second fracture data based on the first resistivity, the second resistivity, the third resistivity, and the first fracture data; the second fracture data is the distribution of non-through fractures in the core sample; The sandification degree of the dolomite is classified according to the first fracture data and the second fracture data.

2. A method for grading the degree of sandification of dolomite in tunnel construction according to claim 1, characterized in that: Calculating second crack data according to the first resistivity, the second resistivity, the third resistivity, and the first crack data includes: Inputting the first resistivity and the third resistivity into a preset Archie model to generate a first formula; the water saturation and porosity in the first formula are first unknowns; Inputting the second resistivity and the third resistivity into a preset Archie model to generate a second formula; the water saturation and porosity in the second formula are second unknowns; Establishing an association relationship between a first unknown number and a second unknown number through the first crack data; The first formula, the second formula and the association relationship are combined to calculate the second unknown, and the second crack data is calculated based on the second unknown.

3. A method for grading the degree of sandification of dolomite in tunnel construction according to claim 2, characterized in that: The Archie model is the correspondence between rock resistivity, porosity, resistivity of solid-liquid mixture in pores and water saturation; Inputting the first resistivity and the third resistivity into a preset Archie model to generate a first formula includes: Taking the first resistivity as the rock resistivity and the third resistivity as the resistivity of the solid-liquid mixture in the pores into the Archie model; Inputting the second resistivity and the third resistivity into a preset Archie model to generate a second formula includes: The second resistivity is taken as the rock resistivity, and the third resistivity is taken as the resistivity of the solid-liquid mixture in the pores and brought into the Archie model.

4. A method for grading the degree of sandification of dolomite in tunnel construction according to claim 3, characterized in that: Establishing an association relationship between a first unknown and a second unknown using the first fracture data includes: Setting the porosity of the first unknown and the second unknown to be the same as a first association relationship; The first fracture data is combined with the water saturation as the discharged water volume data and the change of the water saturation in the second unknown is calculated to form a second correlation relationship; The first association relationship and the second association relationship are regarded as the association relationship between the first unknown number and the second unknown number.

5. The method for grading the degree of sandification of dolomite in tunnel construction according to claim 1, characterized in that: Identifying through-fissures according to the appearance characteristics of the core sample and calculating first fissure data according to the size of the through-fissures includes: Acquiring side images of the core sample in multiple directions under sufficient lighting conditions; splicing the side images into a side expanded image of the core sample; Through cracks are identified from the side expanded image, and an average value of crack widths of the same through crack is calculated as the first crack data.

6. A tunnel construction dolomite sandification degree grading system based on the method according to any one of claims 1 to 5, characterized in that: include: a transient electromagnetic instrument configured to obtain the apparent resistivity of a target section by a transient electromagnetic method; a first calculation unit configured to calculate an average resistivity of a target drilling area as a first resistivity based on the apparent resistivity; a drilling unit configured to drill in the target drilling area to obtain a core sample; a testing unit configured to measure the resistivity of the core sample as a second resistivity and to measure the resistivity of a solid-liquid mixture in fractures of the core sample as a third resistivity; an identification unit configured to identify through-going fractures based on appearance characteristics of the core sample; a second calculation unit configured to calculate first crack data according to the size of the through crack; a third calculation unit configured to calculate second fracture data based on the first resistivity, the second resistivity, the third resistivity, and the first fracture data; the second fracture data is a distribution of non-through fractures in the core sample; The classification unit is configured to classify the degree of sandification of the dolomite according to the first fracture data and the second fracture data.

7. A tunnel construction dolomite sandification degree grading system according to claim 6, characterized in that: The third computing unit is further configured to: Inputting the first resistivity and the third resistivity into a preset Archie model to generate a first formula; the water saturation and porosity in the first formula are first unknowns; Inputting the second resistivity and the third resistivity into a preset Archie model to generate a second formula; The water saturation and porosity in the second formula are the second unknowns; Establishing an association relationship between a first unknown number and a second unknown number through the first crack data; The first formula, the second formula and the association relationship are combined to calculate the second unknown, and the second crack data is calculated based on the second unknown.

8. A tunnel construction dolomite sandification degree grading system according to claim 7, characterized in that: The Archie model is the correspondence between rock resistivity, porosity, resistivity of solid-liquid mixture in pores and water saturation; The third computing unit is further configured to Taking the first resistivity as the rock resistivity and the third resistivity as the resistivity of the solid-liquid mixture in the pores into the Archie model; The second resistivity is taken as the rock resistivity, and the third resistivity is taken as the resistivity of the solid-liquid mixture in the pores and brought into the Archie model.

9. A tunnel construction dolomite sandification degree grading system according to claim 8, characterized in that: The third computing unit is further configured to: Setting the porosity of the first unknown and the second unknown to be the same as a first association relationship; The first fracture data is combined with the water saturation as the discharged water volume data and the change of the water saturation in the second unknown is calculated to form a second correlation relationship; The first association relationship and the second association relationship are regarded as the association relationship between the first unknown number and the second unknown number.

10. A tunnel construction dolomite sandification degree grading system according to claim 6, characterized in that: The identification unit is further configured to: Acquiring side images of the core sample in multiple directions under sufficient lighting conditions; splicing the side images into a side expanded image of the core sample; Through cracks are identified from the side expanded image, and an average value of crack widths of the same through crack is calculated as the first crack data.

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