Grouting method for fault fracture zone tunnel based on numerical simulation

Abstract

The present invention discloses a method for tunnel grouting based on numerical simulation of fault fracture zone, including: obtaining geological data of the tunnel construction section; predicting the geological conditions in front of the tunnel face in the tunnel construction section based on the advanced geological prediction method to obtain the prediction results of the geological conditions in front of the tunnel face; inputting the geological data and the prediction results of the geological conditions in front of the tunnel face into a pre-trained three-dimensional numerical model of the fault fracture zone to obtain the prediction results of the fault fracture zone; determining the tunnel construction grouting scheme based on the fault fracture zone prediction results; and completing the grouting of the tunnel construction section based on the tunnel construction grouting scheme. By accurately predicting the fault fracture zone of the tunnel, the geological conditions and problems that may be encountered during construction can be simulated, which is helpful to formulate a reasonable and effective grouting scheme.

Description

Technical Field

[0001] The invention relates to the field of tunnel construction, in particular to a fault fracture zone tunnel grouting method based on numerical simulation. Background Art

[0002] Some tunnels are located in very complex terrain and geological conditions, with serious adverse geological phenomena, faults, karst, gas, water gushing, high ground stress and other problems are very prominent; some tunnels are located in steep canyons, and the construction conditions are very poor; some tunnels are located in areas with a slope of nine degrees or more, and are adjacent to active fault zones. The geological conditions of the fault fracture zone are complex and changeable, and different regions may have different lithology, lithofacies, structures, stress states, etc., which makes it difficult to accurately identify and describe the characteristics of the fault fracture zone. Due to the difficulty in controlling the fault fracture zone, the grouting progress during the tunnel construction process is relatively slow. If you are not careful, it may lead to a chain reaction, which will have a great impact on the construction progress. In view of this, there is an urgent need for an effective method to formulate a grouting plan through the preparation simulation of the fault fracture zone. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems in the above-mentioned technologies to a certain extent. To this end, the purpose of the present invention is to propose an effective grouting scheme when encountering a fault fracture zone during tunnel construction, and to effectively grout the tunnel grouting process based on the effective grouting scheme to improve the safety of tunnel construction;

[0004] To achieve the above object, an embodiment of the present invention proposes a fault fracture zone tunnel grouting method based on numerical simulation, comprising:

[0005] Obtain geological data of the tunnel construction area;

[0006] Based on the advanced geological prediction method, the geological conditions ahead of the tunnel face in the tunnel construction section are predicted to obtain the geological conditions ahead of the tunnel face prediction results;

[0007] The geological data and the predicted results of the geological conditions in front of the tunnel face are input into the pre-trained three-dimensional numerical model of the fault fracture zone to obtain the prediction results of the fault fracture zone;

[0008] Determine the grouting scheme for tunnel construction based on the prediction results of the fault fracture zone;

[0009] Grouting in the tunnel construction section is completed based on the tunnel construction grouting plan.

[0010] Preferably, the obtaining of geological data of the tunnel construction area includes:

[0011] Conduct a survey outside the tunnel construction site, collect rock samples from the tunnel construction site based on the core drilling method and analyze them to determine the rock type of the tunnel construction site;

[0012] Determine the groundwater development in the tunnel construction area based on borehole testing and hydrogeological surveys;

[0013] Determine the cave information of the tunnel construction area based on on-site investigation and historical documents of the tunnel construction area;

[0014] Obtain the surrounding rock parameters of the tunnel construction section based on the geological radar technology, and determine the surrounding rock grade of the tunnel construction section based on the surrounding rock parameters;

[0015] The geological data of the tunnel construction section shall be determined based on the rock type, groundwater development, cave information and surrounding rock grade of the tunnel construction section.

[0016] Preferably, the method of obtaining surrounding rock parameters of the tunnel construction section based on geological radar technology and determining the surrounding rock grade of the tunnel construction section based on the surrounding rock parameters includes:

[0017] Obtain lithology information, crack density and strength information of surrounding rock in tunnel construction area based on geological radar technology;

[0018] Querying a preset surrounding rock parameter-grade table based on the lithology information, crack density and strength information of the surrounding rock;

[0019] The surrounding rock grade of the tunnel construction section is determined based on the query results.

[0020] Preferably, the method of predicting the geological conditions ahead of the tunnel face in the tunnel construction section based on the advanced geological prediction method to obtain the geological conditions ahead of the tunnel face prediction result includes:

[0021] Based on the advanced geological prediction method, obtain the front profile of the tunnel face and various geological parameters in the tunnel construction section;

[0022] Based on the profile and various geological parameters in front of the tunnel face in the tunnel construction section, the geological radar detection method is used to determine the location and size of the unfavorable geological body in front of the tunnel face in the tunnel construction section;

[0023] The location and size of the unfavorable geological body in front of the tunnel face in the tunnel construction section are used as the prediction result of the geological conditions in front of the tunnel face.

[0024] Preferably, the step of determining the tunnel construction grouting scheme based on the fault fracture zone prediction result includes:

[0025] If the fault fracture zone prediction result is a high risk level, the full-section deep hole pre-grouting scheme is adopted;

[0026] If the fault fracture zone prediction result is a medium risk level, the peripheral deep hole pre-grouting scheme is adopted;

[0027] If the predicted result of the fault fracture zone is a low risk level, the surrounding grouting scheme after excavation is adopted.

[0028] Preferably, the method further comprises: real-time monitoring of the grouting condition of the grouting layer during the grouting process in the tunnel construction section;

[0029] The real-time monitoring of the grouting condition of the grouting layer during the grouting process in the tunnel construction section includes:

[0030] During the grouting process of the tunnel construction section based on the tunnel construction grouting plan, the dynamic concentration of the slurry in the grouting layer is detected, and the CT curve of the dynamic concentration of the slurry in the grouting layer changing with time is recorded;

[0031] Based on the pressure detection device, obtain the pt curve of the pressure change in the grouting hole over time;

[0032] During the grouting process, the grouting condition of the grouting layer is monitored in real time based on the CT curve and the PT curve.

[0033] Preferably, the dynamic concentration of the slurry in the grouting layer is detected, including:

[0034] Obtain the injection status and grouting hole information in the grouting process;

[0035] Determining the dynamic concentration of the slurry in the grouting layer according to the injection state and grouting hole information in the grouting process;

[0036]

[0037] Where T represents the dynamic concentration of the slurry in the grouting layer, T w Indicates the slurry concentration at the initial grouting, P w represents the initial grouting volume, T S Indicates the instantaneous concentration of the grouting liquid in the main grouting hole, P S Indicates the total amount of grouting liquid in the main grouting hole, P Z It represents the instantaneous mean concentration of the grouting liquid in the grouting hole, P y It represents the total amount of grouting liquid in the sub-grouting holes, and x represents the distance from the monitoring point of the sub-grouting holes in the grouting layer to the grouting source.

[0038] Preferably, the method for obtaining a pre-trained three-dimensional numerical model of a fault fracture zone comprises:

[0039] According to the initial stress field, the connection relationship between nodes and the boundary conditions, a three-dimensional numerical model of the tunnel surrounding rock is established based on the principles of rock mechanics, and the established three-dimensional numerical model of the tunnel surrounding rock is optimized and evaluated. When the evaluation results are qualified, the optimized three-dimensional numerical model of the tunnel surrounding rock is obtained;

[0040] The boundary conditions of the numerical model and the microscopic mechanical parameters of the numerical model are input into the numerical model for numerical simulation to obtain the numerical model of the fault fracture zone of the tunnel, and the numerical model of the fault fracture zone of the tunnel is optimized and evaluated. When the evaluation result is qualified, the optimized numerical model of the fault fracture zone of the tunnel is obtained;

[0041] The three-dimensional numerical model of the fault fracture zone is obtained based on the optimized three-dimensional numerical model of the tunnel surrounding rock and the optimized numerical model of the fault fracture zone of the tunnel.

[0042] Preferably, the three-dimensional numerical model of the tunnel surrounding rock is established based on the initial stress field, the connection relationship between nodes and the boundary conditions based on the principle of rock mechanics, including:

[0043] Get the tunnel sample data set;

[0044] Extract the tunnel geometry and material properties of the surrounding rock mass based on the tunnel sample dataset;

[0045] According to the geometric shape of the tunnel and the material properties of the surrounding rock mass in the tunnel sample data set, the tunnel surrounding rock is divided into grid units based on the finite difference method, nodes are set in each grid unit, and the connection relationship between the nodes is determined;

[0046] According to geological data and rock mechanics test results, the initial stress field of the model is set;

[0047] Define the boundary conditions of the model according to the actual environment and geological conditions of the tunnel;

[0048] According to the initial stress field, the connection relationship between nodes and boundary conditions, a three-dimensional numerical model of the tunnel surrounding rock is established based on the principles of rock mechanics.

[0049] Preferably, the step of inputting the boundary conditions of the numerical model and the microscopic mechanical parameters of the numerical model into the numerical model for numerical simulation to obtain the numerical model of the fault fracture zone of the tunnel includes:

[0050] Obtain a sample data set of the fault fracture zone of the tunnel;

[0051] Based on the sample data set of the fault fracture zone in the tunnel, the size, geometry and particle characteristics of the fractured layer are determined;

[0052] According to the size, geometry and particle characteristics of the fractured layer, a numerical model is established based on the particle discrete element numerical simulation method;

[0053] Define the boundary conditions of the numerical model according to the actual environment and geological conditions of the tunnel fault fracture zone;

[0054] The mesomechanical parameters of the numerical model are determined based on the uniaxial compressive strength, elastic modulus and crack propagation properties of the rock;

[0055] The boundary conditions and micromechanical parameters of the numerical model are input into the numerical model for numerical simulation to obtain the numerical model of the fault fracture zone of the tunnel.

[0056] The beneficial effects of the present invention are as follows: by adopting the advanced geological prediction method, the geological conditions of the tunnel construction area can be predicted in advance, which is helpful to discover potential geological problems such as broken zones and faults, and provide important reference for construction; by inputting geological data and prediction results into the three-dimensional numerical model, accurate fault broken zone prediction can be carried out, and the geological conditions and problems that may be encountered in construction can be simulated, which is helpful to formulate a reasonable and effective grouting plan; based on the fault broken zone prediction results, the grouting plan for tunnel construction can be determined in a targeted manner, and corresponding construction measures can be designed for different geological conditions to improve the grouting effect and construction safety; the grouting plan determined by this method can effectively deal with possible problems such as surrounding rock crushing and mud and water influx, which is helpful to optimize the tunnel construction process and improve construction efficiency; through early prediction and accurate simulation, the formulation of a reasonable grouting plan can reduce the risks and unexpected situations in tunnel construction and ensure the stability and safety of the project.

[0057] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description and the accompanying drawings.

[0058] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0060] Figure 1 is a flow chart of a method for grouting a tunnel in a fault fracture zone based on numerical simulation according to an embodiment of the present invention;

[0061] Figure 2 is a flow chart of obtaining geological data of a tunnel construction section according to one embodiment of the present invention;

[0062] Figure 3 The present invention is a flowchart of obtaining surrounding rock parameters of a tunnel construction section based on geological radar technology and determining the surrounding rock grade of the tunnel construction section based on the surrounding rock parameters according to an embodiment of the present invention. DETAILED DESCRIPTION

[0063] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0064] Example 1

[0065] like Figure 1 As shown, a fault fracture zone tunnel grouting method based on numerical simulation includes:

[0066] S1: Obtain geological data of the tunnel construction area;

[0067] S2: Based on the advanced geological prediction method, the geological conditions ahead of the tunnel face in the tunnel construction section are predicted to obtain the geological conditions ahead of the tunnel face prediction results;

[0068] S3: inputting geological data and geological condition prediction results ahead of the tunnel face into a pre-trained three-dimensional numerical model of the fault fracture zone to obtain the fault fracture zone prediction results;

[0069] S4: Determine the grouting scheme for tunnel construction based on the prediction results of the fault fracture zone;

[0070] S5: Complete grouting in the tunnel construction area based on the tunnel construction grouting plan.

[0071] In this embodiment, the geological data includes data such as rock type, groundwater development status, caves and surrounding rock grades.

[0072] In this embodiment, through advanced geological prediction, the engineering party can understand the geological conditions of the project area in advance, discover potential geological risks in time, provide a scientific basis for engineering design, construction and operation, minimize the risks brought by geological disasters, and ensure the smooth progress of the project.

[0073] In this embodiment, the prediction results include fault fracture zone prediction results of high risk level, medium risk level and low risk level. In this embodiment, the prediction results of the geological conditions in front of the face are geological information in front of the tunnel face, including lithology, structure, cracks, joints, soft soil, landslides and other geological features; using geological radar, seismic exploration, drilling and other technical means to obtain information on underground rock and soil layers; obtaining various geological parameters on the profile in front of the tunnel face, such as the strength of the rock mass, the compressive strength of the rock, the tensile strength, the splitting strength, the stability of the formation and other parameters; measuring the density, length, width and other parameters of the cracks; and sending microwave signals through the geological radar system and recording echo data to obtain underground medium The geological radar data can be processed and interpreted to identify the characteristic reflection signals of different geological bodies; according to the echo characteristics in the geological radar data, it can be judged whether there are unfavorable geological bodies underground, such as faults, landslides, soft strata, rock stratum cavities, etc.; according to the analysis results of the geological radar data, the location of the unfavorable geological body can be determined, and the specific location of the section in front of the face can be accurately located; the size of the unfavorable geological body can be judged by the intensity, depth and shape of the reflected signal, including parameters such as area, thickness and depth.

[0074] In this embodiment, the tunnel construction grouting scheme includes a full-section deep hole pre-grouting scheme, a peripheral deep hole pre-grouting scheme, and a peripheral grouting scheme after excavation.

[0075] The beneficial effects of the above technical scheme are as follows: by adopting the advanced geological prediction method, the geological conditions of the tunnel construction area can be predicted in advance, which is helpful to discover potential geological problems such as broken zones and faults, and provide important reference for construction; by inputting geological data and prediction results into the three-dimensional numerical model, accurate fault broken zone prediction can be carried out, and the geological conditions and problems that may be encountered during construction can be simulated, which is helpful to formulate a reasonable and effective grouting plan; based on the fault broken zone prediction results, the grouting plan for tunnel construction can be determined in a targeted manner, and corresponding construction measures can be designed for different geological conditions to improve the grouting effect and construction safety; the grouting plan determined by this method can effectively deal with possible problems such as surrounding rock crushing and mud and water influx, which is helpful to optimize the tunnel construction process and improve construction efficiency; through early prediction and accurate simulation, the formulation of a reasonable grouting plan can reduce risks and unexpected situations in tunnel construction and ensure the stability and safety of the project.

[0076] Example 2

[0077] like Figure 2 As shown, the step of obtaining geological data of the tunnel construction area includes:

[0078] S11: Conduct a survey on the outside of the tunnel construction site, collect rock samples from the tunnel construction site based on the core drilling method and analyze them to determine the rock type of the tunnel construction site;

[0079] S12: Determine the groundwater development in the tunnel construction area based on borehole detection and hydrogeological survey;

[0080] S13: Determine the karst cave information of the tunnel construction area based on the on-site investigation and historical documents of the tunnel construction area;

[0081] S14: Obtain surrounding rock parameters of the tunnel construction section based on geological radar technology, and determine the surrounding rock grade of the tunnel construction section based on the surrounding rock parameters;

[0082] S15: Determine the geological data of the tunnel construction area based on the rock type, groundwater development, cave information and surrounding rock grade of the tunnel construction area.

[0083] In this embodiment, a suitable location is selected in the tunnel construction area, and a core drill is used to perform drilling operations. The core is continuously cored underground by rotating the drill bit to obtain a core sample; during the drilling and coring process, the core samples obtained will be taken out and recorded, and usually the location, depth and other information will be marked to ensure the accuracy and reliability of the sampling; the obtained core samples need to be properly preserved and clearly marked for subsequent analysis and testing. The core samples are sent to the laboratory for physical property testing, chemical composition analysis, rock thin section observation and other analytical methods to determine the composition, structure, properties and other information of the rock; through the analysis results of the core samples, combined with geological survey data and other relevant information, the rock type of the tunnel construction area, such as granite, sandstone, shale, etc., as well as its characteristics and engineering properties, is determined.

[0084] In this embodiment, a suitable location is selected in the tunnel construction area for drilling. It is usually necessary to consider factors such as geological conditions, groundwater level, and the surrounding environment of the building to select the drilling point. Use a drilling rig to perform drilling operations, record data such as geological conditions and water levels at various depths; analyze the rock and soil samples obtained through drilling, including stratum structure, water content, permeability, etc., to determine the development of groundwater. Conduct geological surveys on the tunnel construction area, including investigations on geological structures, groundwater levels, surrounding water systems, etc. Monitor information such as groundwater levels, groundwater flow directions, and water quality to provide data support for groundwater development. Combined with geological structures and hydrogeological data, analyze the source, recharge path, and discharge path of groundwater to determine the development of groundwater. Through drilling detection and hydrogeological survey data analysis, combined with geological survey data, determine the groundwater level, water quality, hydrogeological characteristics, etc. of the tunnel construction area. According to the development of groundwater, formulate corresponding groundwater treatment plans and tunnel support measures to ensure the safe progress of tunnel construction.

[0085] The beneficial effects of the above technical scheme are: the data obtained through core drilling, hydrogeological survey and other means can help determine the geological characteristics of the tunnel construction area, such as the rock type and groundwater development, and provide an important basis for subsequent engineering design and construction. Based on the historical literature and on-site survey of the tunnel construction area, combined with geological data, possible problems such as karst caves, faults, and deformations can be discovered, so that timely measures can be taken to reduce risks. The surrounding rock parameters are obtained using geological radar technology, and combined with other geological data, the surrounding rock grade of the tunnel construction area is determined to provide a basis for support design and engineering construction; on the basis of a comprehensive understanding of the geological conditions of the tunnel construction area, reasonable engineering plans and support measures can be formulated based on geological data to ensure the safety and smooth progress of tunnel construction.

[0086] Example 3

[0087] like Figure 3 As shown, the method of obtaining surrounding rock parameters of the tunnel construction section based on the geological radar technology and determining the surrounding rock grade of the tunnel construction section based on the surrounding rock parameters includes:

[0088] S141: Obtaining lithology information, crack density and strength information of surrounding rock in tunnel construction area based on geological radar technology;

[0089] S142: querying a preset surrounding rock parameter-grade table based on the lithology information, fracture density and strength information of the surrounding rock;

[0090] S143: Determine the surrounding rock grade of the tunnel construction area based on the query result.

[0091] In this embodiment, geological radar technology is a non-invasive geophysical survey technology that can be used to obtain underground structural information, including lithology information, crack density and strength information of surrounding rocks; geological radar technology can detect different dielectric constants of surrounding rocks, thereby distinguishing different lithologies, such as sandstone, shale, granite, etc.; different lithologies show different characteristics on geological radar images, and the lithology can be identified by analyzing radar reflection waveforms and wave velocity information; cracks are usually manifested as changes or anomalies in reflection waveforms in geological radar images, and the location and density of cracks can be detected and recorded by geological radar technology; crack density information is of great significance to surrounding rock stability assessment and support design; surrounding rock strength information is usually related to factors such as lithology and crack density, and geological radar technology can infer the strength of surrounding rocks through characteristics such as the amplitude and attenuation of reflection waveforms; strength information plays a guiding role in the selection and design of support measures, and can help accurately assess the bearing capacity of surrounding rocks.

[0092] In this embodiment, the surrounding rock parameter-grade table is a surrounding rock grade parameter table formulated based on actual engineering requirements before the construction process.

[0093] The beneficial effects of the above technical scheme are: the surrounding rock information obtained by geological radar technology, including lithology, crack density and strength information, can comprehensively evaluate the stability of the surrounding rock. Combined with the surrounding rock parameter-grade table, the different grades of surrounding rock can be quantitatively divided, providing an important basis for subsequent support design and construction; after determining the surrounding rock grade of the tunnel construction section, corresponding support design schemes and construction measures can be formulated for different surrounding rock grades. For high-grade surrounding rock areas, it may be necessary to strengthen support, while low-grade surrounding rock areas can take lighter support measures, which will help improve the efficiency of engineering construction and ensure construction safety; by determining the surrounding rock grade, the risk of geological disasters that may occur during construction can be effectively controlled and reduced. At the same time, adopting refined support design for areas with different surrounding rock grades will help control construction costs and avoid unnecessary waste of resources; determining the surrounding rock grade can effectively predict the nature and behavior of the surrounding rock, guide the subsequent engineering design and construction process, help improve the quality and safety of tunnel engineering, and reduce the occurrence of construction accidents.

[0094] Example 4

[0095] The method of advanced geological prediction is used to predict the geological conditions ahead of the tunnel face in the tunnel construction section, and the prediction results of the geological conditions ahead of the tunnel face are obtained, including:

[0096] Based on the advanced geological prediction method, obtain the front profile of the tunnel face and various geological parameters in the tunnel construction section;

[0097] Based on the profile and various geological parameters in front of the tunnel face in the tunnel construction section, the geological radar detection method is used to determine the location and size of the unfavorable geological body in front of the tunnel face in the tunnel construction section;

[0098] The location and size of the unfavorable geological body in front of the tunnel face in the tunnel construction section are used as the prediction result of the geological conditions in front of the tunnel face.

[0099] In this embodiment, an on-site geological survey is conducted to obtain geological information in front of the tunnel face, including geological characteristics such as lithology, structure, cracks, joints, soft soil, and landslides; geological radar, seismic exploration, drilling and other technical means are used to obtain information on underground rock and soil layers; various geological parameters on the profile in front of the tunnel face are obtained, such as the strength of the rock mass, the compressive strength, tensile strength, splitting strength of the rock, the stability of the stratum and other parameters; and the density, length, width and other parameters of the cracks are measured.

[0100] In this embodiment, microwave signals are sent through the geological radar system and echo data are recorded to obtain characteristic information of underground media, including interfaces, cracks, and voids of different media; the collected geological radar data are processed and interpreted to identify characteristic reflection signals of different geological bodies; based on the echo characteristics in the geological radar data, it is determined whether there are unfavorable geological bodies underground, such as faults, landslides, soft strata, rock stratum voids, etc.; based on the geological radar data analysis results, the location of the unfavorable geological body is determined, and the specific location of the section in front of the face is accurately located; the size of the unfavorable geological body, including parameters such as area, thickness, and depth, is determined by the intensity, depth, and morphology of the reflected signal.

[0101] In this embodiment, the geological condition prediction result ahead of the tunnel face is the geological characteristics and geological parameters ahead of the tunnel face in the tunnel construction section, and whether there are adverse geological bodies underground, such as faults, landslides, soft strata, rock cavities, etc.

[0102] The beneficial effects of the above technical scheme are: predicting and analyzing the geological conditions in front of the tunnel face can help accurately locate possible unfavorable geological bodies and reduce construction risks caused by geological disasters, rock fractures and other problems; by obtaining the geological profile and various geological parameters in front of the tunnel face in advance, the construction party can formulate a more accurate construction plan based on actual conditions and improve construction efficiency; using geological radar technology to determine the location and scale of unfavorable geological bodies can avoid construction pauses and delays caused by the accidental discovery of unfavorable geological bodies during construction; through geological prediction and detection, the geological conditions of the tunnel construction area can be understood more accurately, which is conducive to formulating reasonable support design and construction technology, and ensuring the quality and stability of the tunnel project.

[0103] Example 5

[0104] The method of determining the tunnel construction grouting scheme based on the fault fracture zone prediction result includes:

[0105] If the fault fracture zone prediction result is a high risk level, the full-section deep hole pre-grouting scheme is adopted;

[0106] If the fault fracture zone prediction result is a medium risk level, the peripheral deep hole pre-grouting scheme is adopted;

[0107] If the predicted result of the fault fracture zone is a low risk level, the surrounding grouting scheme after excavation is adopted.

[0108] In this embodiment, the full-section deep hole pre-grouting scheme includes sampling and analysis of the front of the palm face before implementing the full-section deep hole pre-grouting scheme, and selecting 3 to 5 locations for drilling. According to the results of advanced geological prediction, the distance between the two holes should not be greater than 3m, and the hole diameter should be selected as 110mm, and then the obtained samples are analyzed. The selected drilling holes should ensure water seepage at more than 3 locations as much as possible, and the water output of each hole should be guaranteed to be within 2m 3 / h or more, the total water output is guaranteed to be 20m 3 / h or more.

[0109] When implementing the full-section deep hole pre-grouting scheme, first reinforce the front geology (within 6m of the excavation contour line). Grouting excavation is carried out in units of 40m. The excavation process can be divided into 4 sections for construction. Specifically, the design length of section 1 is 13m, the design length of section 2 is 6m, the design length of section 3 is 9m, and the design length of section 4 is 12m. In actual construction, grouting of each section should be carried out at the same time as excavation. For sections with an unexcavated length of not less than 5m, such as stop grouting sections, they should be reserved before the new grouting section to prevent grouting leakage. The grouting holes on the face are arranged in an umbrella shape, and the holes are arranged in a ring shape from the center to the outside, and the overall shape is plum blossom-shaped; the grouting holes in the face are arranged in a circular shape from the middle to the outside. The rock mass adopts a combination of long holes and short holes for full and comprehensive grouting.

[0110] The grouting material uses cement-water glass double slurry, and different slurry concentrations are used according to the properties and structural conditions of the rock mass. When grouting the grouting material, first the outer ring, then the inner ring, grouting is carried out step by step; the holes arranged in the same circle are grouting in an interval jump manner, first up and then down; if water seepage occurs, the slurry should be filled in the waterless area first, and then the slurry should be filled in the water. This method can fully complete the grouting work.

[0111] In this embodiment, the peripheral deep hole pre-grouting scheme includes a water-rich fault fracture zone and a structural fracture zone, which are relatively thin, and the water-rich section can be penetrated by a single grouting method. Although a large amount of water may be generated, the surrounding rock is relatively stable in areas with general fault conditions such as fault fracture zones and contact zones of different lithologies. The grouting material used in the peripheral deep hole pre-grouting scheme in the second phase is cement-water glass double slurry. The steps before the implementation of the peripheral deep hole pre-grouting scheme and the specific implementation steps of grouting are the same as those of the full-section deep hole pre-grouting scheme.

[0112] In this embodiment, the post-excavation perimeter grouting scheme includes an effective grouting range of the post-excavation perimeter grouting scheme of about 3.5m outside the tunnel excavation contour line, and the grouting is carried out with a specification of The small conduit is used as a grouting pipe, which also plays a role in reinforcing the surrounding rock. The length of each conduit is 3.0m. The spacing between the two conduits is 100cm when laying. The plum blossom layout is also adopted. Cement-water glass double liquid slurry for treating leakage and achieving water blocking and pure cement slurry mainly for reinforcing the surrounding rock and structures are prepared separately. The grouting sequence of each grouting section is to grout from both sides first, and then grout once in the middle. Generally, one hole is grouted at a time. In the case of poor drilling conditions, advance grouting is carried out in two stages.

[0113] The beneficial effects of the above technical scheme are: adopting different levels of grouting schemes for different risk levels of fault fracture zones can more effectively manage and control the geological risks that may be faced during tunnel construction; by adopting corresponding grouting schemes for fault fracture zones with high, medium and low risk levels, the adverse effects that may be brought by the fault fracture zones can be reduced and the smooth progress of construction can be ensured; adopting a full-section deep hole pre-grouting scheme for high-risk fault fracture zones can effectively improve the stability of the surrounding rock and reduce the construction safety hazards caused by faults; adopting peripheral deep holes or peripheral grouting after excavation for medium and low risk fault fracture zones can ensure safety during construction and prevent problems such as landslides and collapses.

[0114] Example 6

[0115] It also includes real-time monitoring of the grouting conditions of the grouting layer during the grouting process in the tunnel construction section;

[0116] The real-time monitoring of the grouting condition of the grouting layer during the grouting process in the tunnel construction section includes:

[0117] During the grouting process of the tunnel construction section based on the tunnel construction grouting plan, the dynamic concentration of the slurry in the grouting layer is detected, and the CT curve of the dynamic concentration of the slurry in the grouting layer changing with time is recorded;

[0118] Based on the pressure detection device, obtain the pt curve of the pressure change in the grouting hole over time;

[0119] During the grouting process, the grouting condition of the grouting layer is monitored in real time based on the CT curve and the PT curve.

[0120] In this embodiment, since the geological conditions of the tunnel construction area may be different during the grouting process, some areas may require thicker slurry for grouting to improve the support effect, while some places may require more diluted slurry to adapt to specific geological environments. Adjusting the concentration of the slurry can affect the diffusion and filling effect of the grouting liquid in the surrounding rock. By adjusting the concentration of the slurry, the permeability, viscosity and hardening time of the grouting liquid can be controlled to achieve the best grouting effect; in the actual construction process, the construction environment may change, for example, changes in factors such as temperature and humidity may affect the properties of the slurry. By adjusting the concentration of the slurry, it is possible to adapt to changes in the construction environment and ensure a stable grouting effect.

[0121] The beneficial effects of the above technical scheme are: by real-time monitoring of the dynamic concentration of the slurry in the grouting layer and the pressure in the grouting hole, the situation in the grouting process can be timely understood, potential problems can be discovered in time and adjustments can be made; drawing CT curves and PT curves is helpful to intuitively reflect the grouting effect and changes in the construction process, providing timely feedback information for construction personnel, which is conducive to adjusting construction parameters and decisions; by monitoring the dynamic concentration of the slurry in the grouting layer and the pressure in the grouting hole, the real-time situation in the construction process can be grasped, helping construction personnel to optimize the grouting process and improve the grouting quality; based on the analysis of CT curves and PT curves, the grouting effect can be evaluated, the construction parameters can be adjusted in time, the uniformity and integrity of the grouting can be improved, and the tunnel support effect can be guaranteed.

[0122] Example 7

[0123] The method of detecting the dynamic concentration of the slurry in the grouting layer comprises:

[0124] Obtain the injection status and grouting hole information in the grouting process;

[0125] Determining the dynamic concentration of the slurry in the grouting layer according to the injection state and grouting hole information in the grouting process;

[0126]

[0127] Where T represents the dynamic concentration of the slurry in the grouting layer, T w Indicates the slurry concentration at the initial grouting, P w represents the initial grouting volume, T S Indicates the instantaneous concentration of the grouting liquid in the main grouting hole, P S Indicates the total amount of grouting liquid in the main grouting hole, P Z It represents the instantaneous mean concentration of the grouting liquid in the grouting hole, P y It represents the total amount of grouting liquid in the sub-grouting holes, and x represents the distance from the monitoring point of the sub-grouting holes in the grouting layer to the grouting source.

[0128] In this embodiment, according to the actual situation of the tunnel construction section, the grouting holes are divided into main grouting holes and sub-grouting holes according to the important relationship of the position; for example, in the full-section deep hole pre-grouting scheme, the grouting holes on the face are arranged in an umbrella shape, and the holes are arranged in a ring shape from the center to the outside. The overall shape is plum blossom-shaped, the central hole is the main grouting hole, and the other grouting holes arranged in a ring shape from the center to the outside are sub-grouting holes. The main grouting hole has a strong grouting capacity and can achieve the grouting effect of the entire grouting layer. The sub-grouting holes are located around the main grouting hole, which can supplement the deficiency of the main grouting hole, ensure that the grouting liquid fully fills the cracks and voids in the tunnel surrounding rock, and improve the grouting effect.

[0129] In this embodiment, the dynamic concentration of the slurry in the grouting layer is detected after a period of time from the start of grouting. When the detection starts, the grouting liquid concentration at this time is set as the slurry concentration at the initial grouting; the grouting volume before the start of the detection is set as the initial grouting volume.

[0130] In this embodiment, when it is determined that the dynamic concentration of the slurry in the grouting layer is greater than or equal to the first preset concentration threshold and less than the second preset concentration threshold, and at the same time the pressure value is greater than or equal to the first preset pressure threshold and less than the second preset pressure threshold, grouting in the tunnel construction section is completed; the second preset concentration threshold is greater than the first preset concentration threshold; the second preset pressure threshold is greater than the first preset pressure threshold.

[0131] The beneficial effects of the above technical solution are: by monitoring and calculating the dynamic concentration of the slurry in the grouting layer, it can help construction personnel understand the grouting quality in real time, ensure the stability and uniformity of the grouting process, and improve the grouting effect; according to the changing trend of the dynamic concentration, deviations and problems can be discovered in time, and construction parameters such as the grouting volume and grouting speed can be quickly adjusted to ensure the accuracy and effectiveness of grouting and improve construction efficiency; through the monitoring and analysis of the dynamic concentration, it can help engineers understand the situation inside the grouting layer, determine the grouting volume distribution according to the changes in the slurry concentration in different areas, optimize the grouting layer structure, and improve the support effect.

[0132] Example 8

[0133] The method for obtaining a pre-trained three-dimensional numerical model of a fault fracture zone comprises:

[0134] According to the initial stress field, the connection relationship between nodes and the boundary conditions, a three-dimensional numerical model of the tunnel surrounding rock is established based on the principles of rock mechanics, and the established three-dimensional numerical model of the tunnel surrounding rock is optimized and evaluated. When the evaluation results are qualified, the optimized three-dimensional numerical model of the tunnel surrounding rock is obtained;

[0135] The boundary conditions of the numerical model and the microscopic mechanical parameters of the numerical model are input into the numerical model for numerical simulation to obtain the numerical model of the fault fracture zone of the tunnel, and the numerical model of the fault fracture zone of the tunnel is optimized and evaluated. When the evaluation result is qualified, the optimized numerical model of the fault fracture zone of the tunnel is obtained;

[0136] The three-dimensional numerical model of the fault fracture zone is obtained based on the optimized three-dimensional numerical model of the tunnel surrounding rock and the optimized numerical model of the fault fracture zone of the tunnel.

[0137] The working principle of the above technical solution is: first, according to the initial stress field, the connection relationship between the nodes and the set boundary conditions, a three-dimensional numerical model of the tunnel surrounding rock is established based on the principle of rock mechanics. In the process of establishment, factors such as the physical properties, mechanical parameters and geological structure of the rock need to be considered, and modeling is carried out through numerical simulation software; the established three-dimensional numerical model of the tunnel surrounding rock is optimized and evaluated to check the stability, accuracy and rationality of the model. If the evaluation result is qualified, it means that the surrounding rock model can be used for subsequent simulation analysis; the boundary conditions and micromechanical parameters of the numerical model are input into the numerical model, and the fault fracture zone is numerically simulated to obtain the numerical model of the tunnel fault fracture zone. The obtained numerical model of the tunnel fault fracture zone is optimized and evaluated, and the stability, strain distribution, fracture condition, etc. of the model are analyzed, and the accuracy of the simulation results is verified. If the evaluation result is qualified, it means that the fault fracture zone model can be used for subsequent analysis and optimization. Based on the optimized three-dimensional numerical model of the tunnel surrounding rock and the numerical model of the fault fracture zone, the two are integrated to obtain the final three-dimensional numerical model of the fault fracture zone. This model can comprehensively consider the interaction between surrounding rock and fault fracture zone, and provide comprehensive numerical analysis and simulation support for fault fracture zone problems during tunnel construction.

[0138] The beneficial effects of the above technical solution are: by establishing and optimizing the three-dimensional numerical model, the conditions of the tunnel surrounding rock and fault fracture zone can be simulated more accurately, providing engineers with more reliable data support; through numerical simulation, the performance of different design schemes in terms of surrounding rock and fault fracture zone can be evaluated, thereby optimizing the grouting scheme of the tunnel project.

[0139] Example 9

[0140] The three-dimensional numerical model of the tunnel surrounding rock is established based on the initial stress field, the connection relationship between nodes and the boundary conditions based on the principles of rock mechanics, including:

[0141] Get the tunnel sample data set;

[0142] Extract the tunnel geometry and material properties of the surrounding rock mass based on the tunnel sample dataset;

[0143] According to the geometric shape of the tunnel and the material properties of the surrounding rock mass in the tunnel sample data set, the tunnel surrounding rock is divided into grid units based on the finite difference method, nodes are set in each grid unit, and the connection relationship between the nodes is determined;

[0144] According to geological data and rock mechanics test results, the initial stress field of the model is set;

[0145] Define the boundary conditions of the model according to the actual environment and geological conditions of the tunnel;

[0146] According to the initial stress field, the connection relationship between nodes and boundary conditions, a three-dimensional numerical model of the tunnel surrounding rock is established based on the principles of rock mechanics.

[0147] In this embodiment, it is first necessary to collect a tunnel sample data set, including the geometric shape information of the tunnel (such as length, width, height, etc.) and the actual material property information of the surrounding rock mass (such as rock type, density, strength parameters, etc.); the collected data is preprocessed, including data cleaning, removal of outliers, data format conversion, etc., to ensure the accuracy and completeness of the data; by analyzing and processing the geometric parameters in the data set, the geometric shape information of the tunnel can be extracted, such as the shape and size of the tunnel cross section, the curve of the tunnel longitudinal section, etc.; based on the rock mass information in the sample data set, the material property information of the surrounding rock mass can be extracted through data processing and analysis technology, such as the type of rock (granite, limestone, etc.), density, elastic modulus, compressive strength, tensile strength and other parameters.

[0148] In this embodiment, grid units are divided in the surrounding rock area according to the geometric shape information of the tunnel. The shape and size of the grid unit can be determined according to the actual situation, and the grid is usually divided in an orthogonal or non-orthogonal manner; a node is set in each grid unit, and the node is usually located at the intersection of the grid, representing a discrete point of the surrounding rock. When setting the node, it is necessary to consider the location and density of the node to ensure an effective discrete representation of the surrounding rock; determining the connection relationship between the nodes is the key to the finite difference method. In general, adjacent nodes are connected by springs or rods to establish a connection relationship, which represents the deformation and stress transfer relationship of the surrounding rock; the nodes and the connection relationship are combined into a node-unit model, in which the nodes represent discrete points of the surrounding rock and the units represent the connection relationship between the nodes. In each grid unit, different types of units (such as spring units and rod units) can be used to describe the mechanical properties of the surrounding rock.

[0149] In this embodiment, the geological structure, stratum occurrence, rock formation inclination and rock formation thickness are determined based on geological exploration data to establish a true and reliable initial model; the magnitude and direction of the underground stress field are determined based on the results of geological structure and rock stress analysis. Generally, the greater the depth of the rock formation, the greater the vertical component of the ground stress; according to the actual situation, the determined ground stress direction and magnitude are used as the initial stress field setting of the model. The initial ground stress field may include vertical stress and horizontal stress, and may also consider the surface loading and underground stress changes caused by excavation. Considering the influence of factors such as geological structure and stratum inclination on the underground stress field, the initial stress field of the model is appropriately adjusted.

[0150] In this embodiment, the boundary position of the model is determined according to the actual situation of the tunnel in the sample data, that is, the position in the model where the boundary conditions need to be applied. The boundary position usually includes the excavation boundary of the tunnel, the surrounding of the support structure and the edge of the simulation area; considering the support structure, geological structure and other conditions around the tunnel, determine the displacement, stress or other boundary conditions that need to be set to ensure that the simulation results are more in line with the actual situation; for fixed boundary structures or strata, displacement boundary conditions can be set to limit the displacement of the corresponding position. For example, the surface may be fixed or restricted by a certain support structure, and the corresponding displacement boundary conditions need to be set; if it is necessary to consider the external load effect, such as surface load, surrounding rock stress, etc., it is necessary to apply loads or loading conditions at the corresponding positions to simulate the stress conditions in the actual environment; in the process of simulating tunnel excavation, it is necessary to consider the corresponding excavation influence, and the interaction boundary conditions between the excavation surface and the surrounding surrounding rock can be applied to consider the deformation and stress changes of the surrounding rock caused by excavation.

[0151] The beneficial effects of the above technical solution are: by obtaining a detailed data set of tunnel samples, including geometric shapes and rock mass property information, it can ensure that the model is established based on real data, thereby improving the accuracy and reliability of the simulation; the numerical model established based on the geometric shapes and rock mass property information extracted from the tunnel sample data and combined with the finite difference method can better reflect the actual situation of the tunnel surrounding rock and improve the authenticity and effectiveness of the model; by dividing the surrounding rock into grid units and setting nodes through the finite difference method, and determining the connection relationship between the nodes, it can more accurately simulate the stress distribution and deformation of the surrounding rock. Setting the initial stress field of the model according to geological data and rock mechanics test results can ensure that the impact of initial stress on the behavior of the surrounding rock is taken into account in the simulation, thereby improving the authenticity and reliability of the model; defining the boundary conditions of the model according to the actual environment and geological conditions of the tunnel can make the simulation closer to the actual situation and provide more accurate results for predicting the stress and deformation of the surrounding rock.

[0152] Example 10

[0153] The boundary conditions of the numerical model and the microscopic mechanical parameters of the numerical model are input into the numerical model for numerical simulation to obtain the numerical model of the fault fracture zone of the tunnel, including:

[0154] Obtain a sample data set of the fault fracture zone of the tunnel;

[0155] Based on the sample data set of the fault fracture zone in the tunnel, the size, geometry and particle characteristics of the fractured layer are determined;

[0156] According to the size, geometry and particle characteristics of the fractured layer, a numerical model is established based on the particle discrete element numerical simulation method;

[0157] Define the boundary conditions of the numerical model according to the actual environment and geological conditions of the tunnel fault fracture zone;

[0158] The mesomechanical parameters of the numerical model are determined based on the uniaxial compressive strength, elastic modulus and crack propagation properties of the rock;

[0159] The boundary conditions and micromechanical parameters of the numerical model are input into the numerical model for numerical simulation to obtain the numerical model of the fault fracture zone of the tunnel.

[0160] In this embodiment, a rock thin section test is performed on the rock sample, and the particle structure, mineral composition and crushing characteristics of the rock are observed through a microscope to understand the particle characteristics and crushing state of the rock; in the collected rock samples, a representative fractured zone is found, and the size and shape are measured and recorded through measuring tools (such as a microscope, digital image processing software, etc.), including parameters such as length, width, and thickness. With the help of a particle analysis instrument, a particle analysis is performed on the rock sample to obtain data such as particle size distribution and particle shape, and further understand the characteristics of the particles in the fractured zone.

[0161] In this embodiment, according to the principle of the particle discrete element numerical simulation method, the particles of the fractured layer are regarded as discrete units, and the interaction forces between the particles are considered in the simulation. A numerical model is established according to the characteristics of the particles and the interaction rules; according to the actual characteristics of the particles, including parameters such as particle size, shape, friction coefficient, etc., the particle parameters required in the numerical simulation are set. A simulation area representing the fractured layer is established in the numerical simulation software, and the size, shape and boundary conditions of the simulation area are set according to the actual situation. The particles are initialized into the simulation area according to the size, shape and distribution of the actual situation, and the initial position and speed of each particle are determined. According to the forces between the particles, including spring force, friction force, etc., the interaction rules between the particles in the simulation are defined. Run the particle discrete element numerical simulation to simulate the deformation, movement and interaction process of the particles in the fractured layer, observe the simulation results and analyze the mutual influence between the particles.

[0162] In this embodiment, the initial position, velocity and other states of each particle at the beginning of the simulation are defined. These initial conditions should reflect the initial state of the actual fault fracture zone; the boundary processing method of the model is determined according to the actual situation, such as fixed boundary, free boundary, etc. For the simulation of the fault fracture zone of the tunnel, the constraints of the tunnel surrounding rock and other conditions are usually considered. Considering the external load conditions, such as the effects of surface loads, earthquakes, etc. on the fault fracture zone, the corresponding loading conditions are set according to the actual situation. Determine the approximate conditions that need to be applied in the model, such as the constraints of the surrounding rock, the influence of groundwater, etc., to ensure the accuracy of the simulation results. Define the processing methods of the spring force and friction between the particles to simulate the interaction between the particles in actual situations; set the simulation time step and the overall simulation time to ensure the stability and accuracy of the simulation.

[0163] In this embodiment, the uniaxial compressive strength is the ability of rock to resist compressive loads. According to the uniaxial compressive strength of rock, the failure criterion and strength parameters between particles can be determined. Commonly used models include Mohr-Coulomb model, Drucker-Prager model, etc. These models need to rely on uniaxial compressive strength as basic parameters; elastic modulus reflects the deformation performance of rock under external loading force. The spring stiffness coefficient between particles can be determined according to the elastic modulus to simulate the elastic deformation behavior of rock. Cracks play an important role in the rock destruction process, and the expansion properties of cracks can be described by parameters such as initial crack shape and expansion rate. In numerical simulation, cracks can be considered as interfaces or additional particles in the simulation for modeling, and the crack expansion properties can be used to simulate the destruction process of rock. According to the uniaxial compressive strength, elastic modulus and crack expansion properties of rock, the interaction law between particles, such as spring stiffness coefficient, friction coefficient, failure criterion, etc., can be determined to simulate the destruction and deformation process of rock.

[0164] The beneficial effect of the above technical solution is that by obtaining a sample data set of the fault crushing zone of the tunnel and determining the boundary conditions and micromechanical parameters according to the actual situation, the established numerical model can more realistically reflect the characteristics and behavior of the fault crushing zone of the tunnel, and provide more accurate simulation results. Numerical simulation can present the complex behavior of the fault crushing zone of the tunnel in a visual form, helping engineers and researchers to more intuitively understand the evolution process and characteristics of the fault crushing zone of the tunnel. Based on the results of numerical simulation, the problems that may be encountered during the design and construction of the tunnel can be predicted and evaluated, so as to optimize the design scheme, reduce risks, and ensure the safety and reliability of the project. Through numerical simulation, the behavior of the fault crushing zone of the tunnel can be analyzed from all aspects, providing guidance for engineering construction, optimizing the construction scheme, and avoiding unexpected situations.

[0165] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A method for grouting a fault fracture zone tunnel based on numerical simulation, characterized in that: include: Obtain geological data of the tunnel construction area; Based on the advanced geological prediction method, the geological conditions ahead of the tunnel face in the tunnel construction section are predicted to obtain the geological conditions ahead of the tunnel face prediction results; The geological data and the predicted results of the geological conditions in front of the tunnel face are input into the pre-trained three-dimensional numerical model of the fault fracture zone to obtain the prediction results of the fault fracture zone; Determine the grouting scheme for tunnel construction based on the prediction results of the fault fracture zone; Complete grouting in the tunnel construction area based on the tunnel construction grouting plan; The step of obtaining geological data of the tunnel construction area includes: Conduct a survey outside the tunnel construction site, collect rock samples from the tunnel construction site based on the core drilling method and analyze them to determine the rock type of the tunnel construction site; Determine the groundwater development in the tunnel construction area based on borehole testing and hydrogeological surveys; Based on the on-site investigation and historical documents of the tunnel construction area, determine the karst cave information of the tunnel construction area; Obtain surrounding rock parameters of the tunnel construction area based on geological radar technology, and determine the surrounding rock grade of the tunnel construction area based on the surrounding rock parameters; Determine the geological data of the tunnel construction area based on the rock type, groundwater development, cave information and surrounding rock grade of the tunnel construction area; The method of obtaining surrounding rock parameters of the tunnel construction section based on the geological radar technology and determining the surrounding rock grade of the tunnel construction section based on the surrounding rock parameters includes: Obtain lithology information, crack density and strength information of surrounding rock in tunnel construction area based on geological radar technology; Querying a preset surrounding rock parameter-grade table based on the lithology information, crack density and strength information of the surrounding rock; Determine the surrounding rock grade of the tunnel construction area based on the query results; The method of advanced geological prediction is used to predict the geological conditions ahead of the tunnel face in the tunnel construction section, and the prediction results of the geological conditions ahead of the tunnel face are obtained, including: Based on the advanced geological prediction method, obtain the front profile of the tunnel face and various geological parameters in the tunnel construction section; Based on the profile and various geological parameters in front of the tunnel face in the tunnel construction section, the geological radar detection method is used to determine the location and size of the unfavorable geological body in front of the tunnel face in the tunnel construction section; The location and size of the unfavorable geological body in front of the tunnel face in the tunnel construction section are used as the prediction result of the geological conditions in front of the tunnel face.

2. The method for grouting a tunnel in a fault fracture zone based on numerical simulation according to claim 1, characterized in that: The method of determining the tunnel construction grouting scheme based on the fault fracture zone prediction result includes: If the fault fracture zone prediction result is a high risk level, the full-section deep hole pre-grouting scheme is adopted; If the fault fracture zone prediction result is a medium risk level, the peripheral deep hole pre-grouting scheme is adopted; If the predicted result of the fault fracture zone is a low risk level, the surrounding grouting scheme after excavation is adopted.

3. The method for grouting a tunnel in a fault fracture zone based on numerical simulation according to claim 1, characterized in that: It also includes real-time monitoring of the grouting conditions of the grouting layer during the grouting process in the tunnel construction section; The real-time monitoring of the grouting condition of the grouting layer during the grouting process in the tunnel construction section includes: During the grouting process of the tunnel construction section based on the tunnel construction grouting plan, the dynamic concentration of the slurry in the grouting layer is detected, and the CT curve of the dynamic concentration of the slurry in the grouting layer changing with time is recorded; Based on the pressure detection device, obtain the pt curve of the pressure change in the grouting hole over time; During the grouting process, the grouting condition of the grouting layer is monitored in real time based on the CT curve and the PT curve.

4. The method for grouting a tunnel in a fault fracture zone based on numerical simulation according to claim 1, characterized in that: The method for obtaining a pre-trained three-dimensional numerical model of a fault fracture zone comprises: According to the initial stress field, the connection relationship between nodes and the boundary conditions, a three-dimensional numerical model of the tunnel surrounding rock is established based on the principles of rock mechanics, and the established three-dimensional numerical model of the tunnel surrounding rock is optimized and evaluated. When the evaluation results are qualified, the optimized three-dimensional numerical model of the tunnel surrounding rock is obtained; The boundary conditions of the numerical model and the microscopic mechanical parameters of the numerical model are input into the numerical model for numerical simulation to obtain the numerical model of the fault fracture zone of the tunnel, and the numerical model of the fault fracture zone of the tunnel is optimized and evaluated. When the evaluation result is qualified, the optimized numerical model of the fault fracture zone of the tunnel is obtained; The three-dimensional numerical model of the fault fracture zone is obtained based on the optimized three-dimensional numerical model of the tunnel surrounding rock and the optimized numerical model of the fault fracture zone of the tunnel.

5. The method for grouting a tunnel in a fault fracture zone based on numerical simulation according to claim 4, characterized in that: The three-dimensional numerical model of the tunnel surrounding rock is established based on the initial stress field, the connection relationship between nodes and the boundary conditions based on the principles of rock mechanics, including: Get the tunnel sample data set; Extract the tunnel geometry and material properties of the surrounding rock mass based on the tunnel sample dataset; According to the geometric shape of the tunnel and the material properties of the surrounding rock mass in the tunnel sample data set, the tunnel surrounding rock is divided into grid units based on the finite difference method, nodes are set in each grid unit, and the connection relationship between the nodes is determined; According to geological data and rock mechanics test results, the initial stress field of the model is set; Define the boundary conditions of the model according to the actual environment and geological conditions of the tunnel; According to the initial stress field, the connection relationship between nodes and boundary conditions, a three-dimensional numerical model of the tunnel surrounding rock is established based on the principles of rock mechanics.

6. The method for grouting a tunnel in a fault fracture zone based on numerical simulation according to claim 4, characterized in that: The boundary conditions of the numerical model and the microscopic mechanical parameters of the numerical model are input into the numerical model for numerical simulation to obtain the numerical model of the fault fracture zone of the tunnel, including: Obtain a sample data set of the fault fracture zone of the tunnel; Based on the sample data set of the fault fracture zone in the tunnel, the size, geometry and particle characteristics of the fractured layer are determined; According to the size, geometry and particle characteristics of the fractured layer, a numerical model is established based on the particle discrete element numerical simulation method; Define the boundary conditions of the numerical model according to the actual environment and geological conditions of the tunnel fault fracture zone; The micromechanical parameters of the numerical model are determined based on the uniaxial compressive strength, elastic modulus and crack propagation properties of the rock; The boundary conditions and micromechanical parameters of the numerical model are input into the numerical model for numerical simulation to obtain the numerical model of the fault fracture zone of the tunnel.

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