Tunnel water inflow calculation method and system based on geophysical prospecting parameters and near-field dynamics

Abstract

The invention provides a tunnel water inflow calculation method and system based on geophysical prospecting parameters and near-field dynamics, and relates to the field of tunnel engineering and geotechnical engineering.A rock mass area with the water inflow to be calculated serves as a target area, and the calculation steps are as follows: obtaining geophysical prospecting data of the target area in front of a tunnel face; according to geophysical prospecting data, dispersing the target area into a plurality of material points, and constructing a numerical calculation model of the target area in front of the tunnel face; on the basis of the initialized numerical calculation model, excavation disturbance simulation is conducted through a near-field dynamics solid field and fluid field coupling equation till the excavation process is finished; wherein in excavation disturbance simulation, the water inflow of an overflowing section in a target area is calculated in real time through an equivalent node flow method; according to the method, geophysical prospecting multi-source data and the near-field dynamics theory are fused, and high-precision analysis of tunnel water inflow prediction and the fracture evolution process is achieved.

Description

Technical Field

[0001] The present invention relates to the fields of tunnel engineering and geotechnical engineering, and in particular to a method and system for calculating tunnel water inflow based on geophysical parameters and peri-field dynamics. Background Art

[0002] With the rapid growth of infrastructure construction, a large number of tunnel projects need to traverse complex hydrogeological environments such as karst areas and fault zones. These areas are prone to frequent groundwater activity, making sudden water inrush disasters very likely to occur during tunnel construction, severely impacting construction safety and project progress.

[0003] In the field of tunnel engineering, the development of geophysical exploration technology has led to its widespread application in the measurement of geotechnical parameters. However, a single geophysical method often struggles to accurately measure both rock mechanical properties and hydrological permeability characteristics, resulting in insufficient key parameters for water inflow prediction and limited accuracy. Traditional numerical simulation methods, based on the theory of continuum mechanics, have limitations when simulating the initiation and propagation of rock fractures and the evolution of complex seepage channels. They also struggle to effectively address discontinuities, impacting their reliability and accuracy in tunnel water inflow prediction.

[0004] Therefore, the existing methods for calculating tunnel water inflow have problems such as inaccurate rock mass parameter acquisition, difficulty in simulating the dynamic expansion of cracks, and significant boundary effects. Summary of the Invention

[0005] In order to solve the above problems, the present invention proposes a tunnel water inflow calculation method and system based on geophysical parameters and peri-field dynamics. By integrating geophysical multi-source data and peri-field dynamics theory, high-precision prediction of tunnel water inflow and analysis of crack evolution process are achieved.

[0006] According to some embodiments, the present invention adopts the following technical solutions: The tunnel water inflow calculation method based on geophysical parameters and peridynamics takes the rock mass area to be calculated as the target area. The calculation steps are as follows: Obtain geophysical data of the target area in front of the tunnel face; Based on the geophysical data, the target area is discretized into several material points, and a numerical calculation model of the target area in front of the tunnel face is constructed; Based on the initialized numerical calculation model, the excavation disturbance simulation is carried out using the coupling equations of the peridynamic solid field and fluid field until the excavation process is completed. Among them, in the excavation disturbance simulation, the equivalent node flow method is used to calculate the water inflow of the flow section in the target area in real time.

[0007] According to some embodiments, the present invention adopts the following technical solutions: The tunnel water inflow calculation system based on geophysical parameters and peridynamics takes the rock mass area where the water inflow is to be calculated as the target area, including: The acquisition module is configured to: acquire geophysical data of a target area in front of the tunnel face; The construction module is configured to: discretize the target area into a number of material points based on the geophysical exploration data, and construct a numerical calculation model of the target area in front of the tunnel face; The simulation module is configured to: perform excavation disturbance simulation based on the initialized numerical calculation model and using the peridynamic solid field and fluid field coupling equations until the excavation process is completed; Among them, in the excavation disturbance simulation, the equivalent node flow method is used to calculate the water inflow of the flow section in the target area in real time.

[0008] According to some embodiments, the present invention adopts the following technical solutions: A computer program product includes a computer program. When the computer program is executed by a processor, the method for calculating the tunnel water inflow based on geophysical parameters and peri-field dynamics is implemented.

[0009] According to some embodiments, the present invention adopts the following technical solutions: A non-transitory computer-readable storage medium is used to store computer instructions. When the computer instructions are executed by a processor, the method for calculating tunnel water inflow based on geophysical parameters and peri-field dynamics is implemented.

[0010] According to some embodiments, the present invention adopts the following technical solutions: An electronic device comprises: a processor, a memory and a computer program; wherein the processor is connected to the memory, and the computer program is stored in the memory. When the electronic device is running, the processor executes the computer program stored in the memory, so that the electronic device implements the tunnel water inflow calculation method based on geophysical parameters and near-field dynamics.

[0011] Compared with the prior art, the present invention has the following beneficial effects: (1) Through multi-parameter geophysical exploration, the key parameters of the rock mass ahead of the tunnel face are obtained by inversion, which breaks through the limitation of insufficient information of a single geophysical exploration method, significantly improves the accuracy of rock mass mechanics and hydrogeological parameters, and provides a reliable data basis for water inflow prediction.

[0012] (2) The use of the peridynamic theory of non-local action overcomes the problem that the traditional continuous medium model cannot simulate the initiation, expansion and discontinuous deformation of rock cracks. It can truly reflect the dynamic evolution process of the crack channel under excavation disturbance, thereby more accurately characterizing the seepage path and water gushing mechanism.

[0013] (3) Through the bidirectional coupling calculation of solid field and fluid field, combined with the excavation disturbance algorithm of gradual stress release and the equivalent node flow method, dynamic and high-precision prediction of water inflow during tunnel construction is achieved, effectively improving the early warning capability of water inflow disasters under complex geological conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The accompanying drawings, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0015] Figure 1 This is the water inflow calculation framework based on geophysical multi-parameter peridynamics in Example 1.

[0016] Figure 2 Schematic diagram of the peridynamic material point principle of Example 1.

[0017] Figure 3 Schematic diagram of stress release during the excavation disturbance process of Example 1. DETAILED DESCRIPTION

[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0019] It should be noted that the following detailed descriptions are exemplary and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present invention belongs.

[0020] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "comprising" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0021] Peridynamics is a new numerical simulation method based on the principle of nonlocal action. It replaces traditional differential equations with integral equations, avoiding the mathematical singularity caused by stress concentration at the crack tip. It can effectively describe the spontaneous initiation, evolution, and failure process of material cracks. It also has a unified form of fluid field and solid mechanics field, which facilitates coupled calculations. In addition, peridynamics does not require special treatment when dealing with large deformation problems, and can naturally simulate the discontinuous changes of the rock mass during crack expansion. It is particularly suitable for simulating the progressive failure process of the rock mass caused by tunnel excavation unloading and the dynamic evolution mechanism of the seepage channel. Therefore, the peridynamic model combined with multi-parameter geophysical exploration technology can more comprehensively and accurately reveal the evolution law of tunnel water inrush disasters and achieve high-precision and high-efficiency prediction of water inrush volume, which has important theoretical significance and application value for ensuring the safety of tunnel construction.

[0022] The present invention provides a method and system for calculating tunnel water inflow based on geophysical parameters and peri-field dynamics. The method aims to solve the problems of inaccurate rock mass parameter acquisition, difficulty in simulating dynamic expansion of cracks, and significant boundary effects in traditional methods by integrating multi-source geophysical data and peri-field dynamics theory, thereby realizing high-precision prediction of tunnel water inflow and analysis of crack evolution process.

[0023] Example 1 In one embodiment of the present invention, a method for calculating tunnel water inflow based on geophysical parameters and peridynamics is provided. The rock mass area for which water inflow is to be calculated is used as the target area. The calculation steps are as follows: Obtain geophysical data of the target area in front of the tunnel face; Based on the geophysical data, the target area is discretized into several material points, and a numerical calculation model of the target area in front of the tunnel face is constructed; Based on the initialized numerical calculation model, the excavation disturbance simulation is carried out using the coupling equations of the peridynamic solid field and fluid field until the excavation process is completed. Among them, in the excavation disturbance simulation, the equivalent node flow method is used to calculate the water inflow of the flow section in the target area in real time.

[0024] As an embodiment, the tunnel water inflow calculation method based on geophysical parameters and peridynamics of the present invention realizes high-precision analysis of tunnel water inflow prediction and crack evolution process by integrating geophysical multi-source data and peridynamic theory. Figure 1 The specific implementation process is as follows: S1 Geophysical multi-parameter acquisition and discrete modeling; Using TSP (Tunnel Seismic Prediction) method, seismic wave method, hydrological field method and other methods, geophysical data (such as longitudinal wave velocity, shear wave velocity, rock density and water pressure data at discrete measuring points) in front of the tunnel face are obtained, physical parameters (such as density, elastic modulus, Poisson's ratio, initial permeability and initial water pressure properties) are calculated, and a discrete numerical calculation model is established.

[0025] Among them, the specific operation steps of the TSP method and seismic wave method are: Stimulate seismic waves on the tunnel face, receive the reflection and refraction signals of the seismic waves through the arranged detectors, analyze the propagation speed and waveform characteristics of the seismic waves, analyze the arrival time and propagation path of the reflected waves, and calculate the longitudinal wave velocity and shear wave velocity , the Poisson's ratio in front of the face can be obtained and dynamic elastic modulus , which can be expressed as: (1) in, is Poisson's ratio, ρ is rock density, which are obtained through field tests. In addition, dynamic elastic modulus can be obtained by using empirical formulas or experimental data fitting. Obtain static elastic modulus .

[0026] The specific operation steps of the hydrological field are as follows: Multiple measuring points are arranged in front of the tunnel face. Water level gauges or pressure sensors are installed through drilling holes to measure the water pressure value. Based on the measured water pressure value, the discrete water pressure value is interpolated to the entire target area using the interpolation method to form a continuous water pressure field. , and then according to Darcy's law and the seepage control equation, the seepage field model in front of the tunnel face is established. The seepage control equation is: (2) in, The permeability coefficient in front of the tunnel face is calculated, and the objective function is minimized using the least squares method or other optimization algorithms (such as genetic algorithm, particle swarm optimization, etc.) to achieve permeability coefficient inversion.

[0027] Since the permeability coefficient in water-bearing caves or cracks is very large, the permeability coefficient obtained is Classify and determine the critical value by experience or indoor test ,when , the location is marked as a water-bearing cave or fissure area.

[0028] At this point, the geophysical method has been used to obtain the physical parameters in front of the tunnel face and complete the regional division. The regional division here is to divide the target area into water-bearing cave area, fracture area and complete rock area. Only the water-bearing cave or fracture area is specially marked, and the rest is general rock mass without specific marking.

[0029] The discrete modeling is specifically as follows: The rock mass area in front of the tunnel face to be studied for water inflow is discretized into a set of material points in space. It is the mechanical characteristics and parameters of the rock mass, that is, physical parameters, including elastic modulus , Poisson's ratio ,density ρ , permeability coefficient , initial water pressure and other physical parameters , for two-dimensional analysis, construct the physical information set of the research domain : (3) S2 peridynamics solid field and fluid field coupling equation; Figure 2 is the principle diagram of peridynamic material points, such as Figure 2 As shown, Represents a material point The circular neighborhood of for Other interacting material points in the neighborhood, is the neighborhood radius, for The speed at time t, for 、 The relative position vector of is the relative displacement of the material point after the shape changes, based on Figure 2 The peridynamic material point principle in step S1 is used, and the solid field peridynamic control equation and nonlocal force density in step S1 are expressed as follows: (4) (5) in, for exist t The acceleration of time, is the solid density, for The physical strength of is the force density of classical peridynamics, Indicates the interaction point The volume, 、 They are 、 The position after deformation, is the relative displacement of the material point after the shape changes, is the micro potential energy at a point, is the micromodulus of the model, is the elongation of the key.

[0030] Elongation Expressed as: (6) For two-dimensional analysis, the micromodulus According to the elastic modulus and Poisson's ratio Sure: (8) in, is the neighborhood radius, is the thickness. So far, all peridynamic parameters can be calculated from the physical information set in S1. get.

[0031] Furthermore, in the S2 fluid field peridynamics theory, the fractured rock mass is divided into the matrix region and fracture zones , material point and The key between (i.e. the bond connecting two material points) is regarded as a fluid channel. Based on Darcy's law, the matrix area exist t Moment Material Point The fluid flow vector for: (9) in, K r The matrix region The macro permeability, p is the fluid pressure.

[0032] According to the law of mass conservation, the governing equation for peridynamic fluid flow is: (10) in, Q b represents the Biot modulus, μ f is the fluid viscosity, ρ f represents the fluid density, is the source and sink term, The permeability of the matrix can be calculated using the peridynamic permeability coefficient equivalent relationship.

[0033] Assuming that the fluid flow in the fracture zone follows Darcy's law, then: (11) in, c f is the compressibility of the fluid, To calculate the permeability of the fracture, the fracture area Macro penetration K f get.

[0034] For two-dimensional analysis, the fracture permeability coefficient K f As the crack opening w Updated by the cubic law: (12) in, μ f is the fluid viscosity.

[0035] Furthermore, the initial permeability can be calculated based on the physical information set in S1. For the area marked as cave, it is set as empty material point and kept full of water pressure.

[0036] According to Biot theory, the force density after coupling of solid mechanical fields can be expressed as: (13) in, α represents the Biot coefficient, γ represents the fluid pore pressure coefficient, Function to determine the breaking state of the connecting bond: (14) in, s 0 is the critical value of bond breaking, and 0 and 1 represent bond breaking and integrity, respectively.

[0037] Based on the bond fracture state, the damage parameter at the material point x is defined as: (15) when When , it means that all bonds at x are broken and the point is completely destroyed.

[0038] Determine the crack distribution in the target area by the damage parameters, and then directly measure the crack opening based on the crack distribution w , and finally update the fracture permeability coefficient according to formula (12).

[0039] S3 model rock mass excavation disturbance algorithm in front of the tunnel face; In the rock mass excavation disturbance algorithm in front of the model tunnel face, in the unexcavated stage, the rock mass maintains a stable equilibrium state under the ground stress conditions, and then the excavation step is carried out at the tunnel face, causing the surrounding rock to enter the construction disturbance stage.

[0040] In particular, the stress release ratio is set to simulate the stress release process during tunnel excavation. In this process, the interaction force between the material points in the excavation area and the material points outside the excavation area (i.e., the peridynamic nonlocal force) is not directly deleted, such as Figure 3 As shown, the excavation process is divided into multiple stages, and the forces are released gradually, that is, the unbalanced forces are released in stages.

[0041] Furthermore, when all iterative material points are in the non-excavation area, the peridynamic nonlocal interaction force remains unchanged. However, when at least one iterative material point is in the excavation area, the force is Release first Re 1% of the force (i.e., the force becomes the unexcavated state (1- Re 1)%)), after several iterations, it is released in the next stage Re 2% (i.e., it becomes unexcavated state (1- Re 2)%), until the final release of 100% (i.e., becoming 0% of the unexcavated state), the force is set to zero to achieve a complete excavation step simulation. Re 1 and Re 2 is a constant ranging from 0 to 100, which is adjusted according to the specific release rate. Re 1< Re 2. You can also set three-stage or four-stage release according to actual needs. Re 1< Re 2< Re 3< Re 4.

[0042] Furthermore, after excavation is completed, the material points within the excavated area are not deleted; only the interactions between the materials in the areas are changed. The physical information array of the entire material point remains unchanged, eliminating the need for matrix reorganization or re-searching of neighboring material points. The model must be simplified during calculations. When solving deep underground engineering, it is impossible to model all strata from the structure to the surface. To reduce computational costs, only the strata surrounding the structure are modeled, and the remaining strata are simplified to act as boundary conditions around the model.

[0043] S4 numerical solution and water inflow calculation; In the numerical solution and water inflow calculation, an adaptive time step control method that satisfies the Von-Neumann stability condition is adopted. At the same time, to adapt to the stable calculation of quasi-static loading and damage propagation processes, an adaptive dynamic relaxation algorithm consisting of virtual inertia and damping terms is introduced: (16) Where, D is a virtual diagonal density matrix, the vector X and U are the initial position and initial displacement of the discrete points, m is the damping coefficient, is the interacting force vector.

[0044] In addition, the solid field and fluid field control equations (10) and (13) require numerical iteration to solve, obtaining nonlocal forces, displacements, water pressures, and so on. All discrete material points are iteratively calculated within each time step, and a stable solution is finally obtained after multiple time step iterations. The fluid field has a relatively slow velocity and a long time span, while the deformation and destruction process in the solid field has a shorter time span than the seepage process. Therefore, two different time steps are set for the coupled calculation, with the fluid field time step being smaller than the solid field time step.

[0045] Furthermore, the method used to calculate the water inflow is the equivalent node flow method, which expresses the seepage volume on any flow section as the conductivity coefficient Water pressure at material point The algebraic sum of the products of , the calculated accuracy of the seepage flow is of the same order as that of the water pressure solution: (17) in, Indicates that through m The total water inflow of the flow section, mn Indicates the number of material points in the flow section, hm Indicates the number of neighboring material points interacting with the flow section, the conduction coefficient Determined by parameters such as permeability coefficient and unit shape, The water pressure at a material point changes in real time.

[0046] Example 2 In one embodiment of the present invention, a method for calculating tunnel water inflow based on geophysical parameters and peridynamics is provided, taking a deep karst limestone tunnel as an example, including: 1. Project Description 1. Engineering scenarios and raw data collection.

[0047] A deep karst limestone tunnel, 180 meters deep, has a horseshoe-shaped excavation section with a 12-meter span and a 10-meter height. A 20-meter (vertical) x 30-meter (horizontal) area in front of the tunnel face was designated as the target area for water inflow prediction.

[0048] The TSP303 tunnel earthquake advance prediction system was used on site to collect seismic wave data: a φ38mm, 0.3m deep vertical blasthole was drilled in the center of the tunnel face, and a 10g emulsion explosive source cartridge was loaded into the hole. The detonation voltage was 400V, and the measured main frequency was 400Hz. 24 three-component acceleration-type geophones were arranged 2m outside the tunnel face. The geophone model was 28HzSM-24, with a track spacing of 1m, in an "L"-shaped array. The outer ring of geophones was coupled to the tunnel wall with gypsum to ensure a coupling rate of more than 95%. The sampling rate of the acquisition station was set to 20kHz, the recording length was 512ms, and the triggering method was the blaster circuit trigger. A total of two effective shot sets were recorded on site. The signal-to-noise ratio was higher than 25dB after band-pass filtering (80-800Hz). Clear direct P and S waves and reflected phase axes from the front within the depth range of 5-25m were obtained, providing high-fidelity original data for subsequent wave velocity inversion and rock parameter extraction.

[0049] 2. Wave velocity inversion and dynamic elastic parameter calculation.

[0050] First, the STA / LTA (short time window / long time window) algorithm is used to automatically pick the first arrival of each direct P-wave and S-wave, and manual correction is used to ensure that the arrival time error is less than 1ms. Combined with the minimum travel time inversion, a 1D horizontal layered velocity model is established. After 20 inversion iterations, the convergence is obtained to obtain the average longitudinal wave velocity ahead of the tunnel face. V p =4800m / s, shear wave speed V s =2600m / s. The rock density is obtained from the on-site core sampling test. , substituted into the elastic wave theory formula, the dynamic elastic modulus is calculated to be 43.8GPa, and the Poisson's ratio is 0.25. In order to correlate with the static elastic modulus required for peridynamic calculations, six groups of limestone samples were subjected to triaxial compression tests in the laboratory, and the correlation coefficient The static elastic modulus was obtained to be 29.2 GPa. This value, together with the Poisson's ratio, was substituted into the subsequent discrete model, and the error was less than 5% after cross-validation.

[0051] 3. Permeability coefficient inversion and cave identification.

[0052] A horizontal φ75mm advance borehole was constructed at 5m, 10m, and 15m in front of the tunnel face. A micro piezoresistive water pressure gauge was installed in the hole, and the measured stable water pressure was 0.45MPa, 0.62MPa, and 0.78MPa. Using Darcy's law as a constraint, a genetic algorithm (population 40, crossover probability 0.8, mutation probability 0.1, iteration 100 generations) was used to The inversion is performed within the interval of , and the optimal solution is .when When the unit is marked as a cave / fissure area, the permeability coefficient field file k_field.txt is generated accordingly.

[0053] 4. Discrete modeling script and output format.

[0054] The target area is discretized into a 0.5m×0.5m grid, and the node (i.e. material point) coordinates are generated from 0 to 20m in the vertical direction and 0 to 30m in the horizontal direction. Each node is assigned the following values: density , static elastic modulus 29.2GPa, Poisson's ratio 0.25, permeability coefficient k is read from the field file k_field.txt, determine the initial water pressure, and press Mark the cave. The final output is a CSV format file, which is the physical information set. Each row contains the node number, transverse coordinate, longitudinal coordinate, density, elastic modulus, Poisson's ratio, permeability coefficient, initial water pressure, and cave mark, which can be directly called for subsequent peridynamic solutions.

[0055] Example 3 In one embodiment of the present invention, a method for calculating tunnel water inflow based on geophysical parameters and peridynamics is provided, comprising: 1. Model establishment.

[0056] Following step S1, a two-dimensional plane strain calculation domain was established in front of the tunnel face: 30 m horizontally (along the tunnel axis) and 35 m vertically (perpendicular to the tunnel axis). The model was discretized using a regular grid with a grid spacing of 0.25 m, containing 16,800 material points. The neighborhood radius of each material point was set to 3.015 times the grid spacing to meet peridynamic accuracy requirements. The parameters of all material points were then configured.

[0057] 2. Definition of excavation area.

[0058] The "excavation area" is defined within the range of 1.5m of one cycle advance: starting from the current mileage in the horizontal direction of the tunnel face, a 1.5m wide area is divided in the horizontal direction, and the actual excavation area is divided within the range of 11m of the longitudinal tunnel height.

[0059] All material points within the rectangular range are marked as "excavated area points", and the remaining material points are "unexcavated area points". After the marking process is completed, a Boolean array flag(i) is formed, flag(i) = 1 indicates an excavated point, and flag(i) = 0 indicates an unexcavated point. This array remains unchanged in all subsequent sub-steps and is not modified with stress release.

[0060] 3. Gradual stress release plan.

[0061] This embodiment adopts four-stage stress release, and the release ratio is determined based on experience: , , , .

[0062] When all material points are in the “unexcavated region”, the peridynamic nonlocal interaction force remains unchanged. However, when at least one of the iterative material points is in the “excavated region”, the nonlocal force density is negatively correlated due to the empty excavation boundary. Perform step-by-step reduction, reduction factor β The value selection rules are as follows: Stage I: β =0.85, Stage II: β =0.60, Stage III: β =0.25, Stage IV: β =0, the force density is set to zero in stage IV to achieve a complete excavation step simulation.

[0063] Each stage is further divided into three computational iteration sub-steps, with a total of 12 sub-steps to complete 1.5 m of excavation to ensure a smooth transition.

[0064] 4. Excavation array iteration scheme.

[0065] After the "excavation area point" is completed, the material points in the actual corresponding area are not deleted. Only the force density effect between the materials in the area is changed. The physical information array of the overall material points remains unchanged, and there is no need for matrix reorganization and re-retrieval of neighboring material points.

[0066] Example 4 In one embodiment of the present invention, a method for calculating tunnel water inflow based on geophysical parameters and peridynamics is provided, comprising: 1. In step S1, TSP advance detection and borehole water pressure testing were used on site to obtain the longitudinal wave velocity, shear wave velocity, rock density and water pressure data at discrete measuring points within 30 m in front of the tunnel face.

[0067] Based on this data, the Poisson's ratio, elastic modulus, and permeability coefficient were calculated at each location, and the water-bearing fractured areas were labeled "high permeability zones." Subsequently, this section of rock mass was discretized into a set of material points with a side length of 0.2 m. Each point carries five properties: density, elastic modulus, Poisson's ratio, initial permeability coefficient, and initial water pressure, thus completing the discrete modeling.

[0068] After modeling, the model parameters are initialized, mainly including: initializing all calculation parameters according to the geophysical data and model construction, including: the number of material points, neighborhood radius, neighborhood of each material point, boundary conditions, material point coordinates, etc.; at the same time, setting and initializing the non-local forces between material points, elongation between bonds, etc., to lay the foundation for the subsequent coupling calculation of fluid field and solid field; in addition, calculating and initializing the permeability coefficient, conductivity coefficient, etc. of the rock mass.

[0069] 2. Enter step S2, the program automatically establishes a neighborhood list for each material point, and establishes the coupling equations of the solid field and fluid field based on the peridynamics theory.

[0070] In the solid field, rock damage is judged by the elongation and fracture of bonds; in the fluid field, bonds that have not yet broken are regarded as seepage channels through which water can pass.

[0071] In the initial state, all bonds are unbroken, and the macroscopic permeability of the fracture zone is converted into a fracture aperture function by the cubic law, while the permeability of the matrix zone is adopted from the field inversion.

[0072] Fluid-solid coupling is achieved through the Biot coefficient: when the bonds at a certain point gradually break, its equivalent permeability increases accordingly, and the water pressure gradient further drives the seepage, which in turn reduces the effective stress of the rock mass, promotes the breaking of more bonds, and forms a bidirectional coupling.

[0073] 3. Step S3 simulates the excavation disturbance of the tunnel face.

[0074] Here, a 2-meter excavation is divided into four stress-releasing stages: 10% stress release in the first stage, 30% in the second, 60% in the third, and complete release in the fourth. Each stage reduces the interaction forces between material points within the excavation area and their neighbors without deleting any material points. This avoids the need for matrix reorganization in traditional finite element methods while also simulating the loosening of the surrounding rock and the opening of cracks caused by the gradual exposure of the excavation face to the open air.

[0075] 4. After the stress is released, the process proceeds to step S4 to calculate the water inflow.

[0076] At this point, the program sets a vertical flow section on the tunnel face, containing multiple material points. For each point, the current water pressure is read, and the conductivity at that point is calculated based on the cell shape and real-time permeability. The conductivity at each point is then multiplied by the corresponding water pressure, and the algebraic sum of these products across all points in the section is calculated to yield the instantaneous water inflow through the section at that moment.

[0077] Since peridynamics allows permeability to be updated in real time with the fracture aperture, as the excavation step progresses, the permeability of the fracture zone gradually increases, the water pressure difference remains unchanged or even decreases slightly, while the water inflow continues to increase, reflecting the process of "fracture opening - intensified seepage - more fractures opening".

[0078] Example 5 In one embodiment of the present invention, a method for calculating tunnel water inflow based on geophysical parameters and peridynamics is provided, comprising: A1 Geophysical Multi-Parameter Acquisition A2 solves the region construction; A3 calculates and initializes parameters; A4 excavation disturbance simulation; A5 result analysis.

[0079] Furthermore, the A1 geophysical multi-parameter acquisition process primarily involves using geophysical techniques to collect multi-source physical parameters ahead of the tunnel face. This involves exciting seismic waves on the face and deploying geophones to receive reflected and refracted signals. By analyzing the arrival time and propagation path of the reflected waves, the longitudinal and shear wave velocities are calculated, further enabling the Poisson's ratio and dynamic elastic modulus of the rock mass to be determined. Combined with hydrological field measurements, water pressure distribution and permeability parameters are obtained, and areas such as water-bearing caves are marked to construct a physical information set for the study domain.

[0080] Furthermore, the A2 solution region construction primarily involves constructing a numerical model of the area ahead of the tunnel face based on geophysical data. This model includes special areas such as the tunnel excavation area, surrounding rock mass, and karst caves. These areas are discretized to determine the physical properties of each material point, such as elastic modulus, Poisson's ratio, density, permeability, and initial water pressure. Appropriate boundary conditions are also set to ensure that the model boundaries match the actual project and prepare for subsequent fluid-structure interaction analysis.

[0081] Furthermore, the A3 calculation parameter initialization process primarily involves initializing all calculation parameters based on geophysical data and model construction. This includes the number of material points, neighborhood radius, each point's neighborhood, boundary conditions, and material point coordinates. Furthermore, the nonlocal forces between material points and the elongation between bonds are set and initialized, laying the foundation for subsequent coupled calculations of the fluid and solid fields. Furthermore, the rock mass's computational permeability and conductivity are calculated and initialized.

[0082] Furthermore, the A4 excavation disturbance simulation primarily involves setting initial ground stress and water pressure conditions to a stable equilibrium state, dividing the excavation process into multiple stages, and gradually releasing the forces proportionally. During the solid field iteration time step, nonlocal forces, accelerations, displacements, and stresses are calculated. If the elongation exceeds the set critical failure elongation, the bonded nonlocal forces between material points disappear, and the damage parameters and permeability coefficient are updated. The fluid field then updates the water pressure distribution of the rock mass based on the changed permeability coefficient, and uses the equivalent node flow method to calculate the water inflow at the tunnel face until the excavation process is complete.

[0083] Furthermore, the main contents of A5 result analysis are: outputting the simulation results of tunnel face excavation disturbance, visualizing and analyzing the tunnel face water inrush process and water pressure distribution.

[0084] Example 6 In one embodiment of the present invention, a system for calculating tunnel water inflow based on geophysical parameters and peridynamics is provided, wherein the rock mass area for which water inflow is to be calculated is used as a target area, and the system includes: The acquisition module is configured to: acquire geophysical data of a target area in front of the tunnel face; The construction module is configured to: discretize the target area into a number of material points based on the geophysical exploration data, and construct a numerical calculation model of the target area in front of the tunnel face; The simulation module is configured to: perform excavation disturbance simulation based on the initialized numerical calculation model and using the peridynamic solid field and fluid field coupling equations until the excavation process is completed; The calculation module is configured to calculate the water inflow of the flow section in the target area by using the equivalent node flow method after the simulation is completed.

[0085] Example 7 In one embodiment of the present invention, a computer program product is provided, comprising a computer program, which, when executed by a processor, implements the method for calculating tunnel water inflow based on geophysical parameters and peri-field dynamics.

[0086] Example 8 In one embodiment of the present invention, a non-transitory computer-readable storage medium is provided, which is used to store computer instructions. When the computer instructions are executed by a processor, the method for calculating tunnel water inflow based on geophysical parameters and near-field dynamics is implemented.

[0087] Example 9 In one embodiment of the present invention, an electronic device is provided, comprising: a processor, a memory, and a computer program; wherein the processor is connected to the memory, and the computer program is stored in the memory. When the electronic device is running, the processor executes the computer program stored in the memory, so that the electronic device executes the method for calculating tunnel water inflow based on geophysical parameters and near-field dynamics.

[0088] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowcharts and / or block diagrams, as well as combinations of processes and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowcharts and / or block diagrams. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0089] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 The steps for the function specified in one or more boxes.

[0090] Although the above describes the specific embodiments of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without any creative work are still within the scope of protection of the present invention.

Claims

1. A method for calculating tunnel water inflow based on geophysical parameters and peridynamics, characterized by: The rock mass area to be calculated for water inflow is taken as the target area, and the calculation steps are as follows: Obtain geophysical data of the target area in front of the tunnel face; Based on the geophysical data, the target area is discretized into several material points, and a numerical calculation model of the target area in front of the tunnel face is constructed; Based on the initialized numerical calculation model, the excavation disturbance simulation is carried out using the coupling equations of the peridynamic solid field and fluid field until the excavation process is completed. Among them, in the excavation disturbance simulation, the equivalent node flow method is used to calculate the water inflow of the flow section in the target area in real time.

2. The method for calculating tunnel water inflow based on geophysical parameters and peridynamics according to claim 1, characterized in that: The geophysical data are data on longitudinal wave velocity, transverse wave velocity, rock density and water pressure at discrete measuring points within a preset range in front of the tunnel face collected through geophysical technology.

3. The method for calculating tunnel water inflow based on geophysical parameters and peridynamics according to claim 1, characterized in that: The numerical calculation model for the target area in front of the tunnel face is constructed by discretizing the target area into a set of material points in space. Each material point carries density, elastic modulus, Poisson's ratio, initial permeability coefficient and initial water pressure properties, forming a physical information set of the target area.

4. The method for calculating tunnel water inflow based on geophysical parameters and peridynamics according to claim 1, characterized in that: The initialization includes the number of material points, neighborhood radius, neighborhood of each material point, boundary conditions, material point coordinates; non-local forces between material points, elongation between bonds; and calculated permeability and conductivity of the rock mass.

5. The method for calculating tunnel water inflow based on geophysical parameters and peridynamics according to claim 1, characterized in that: The coupling equation of the solid field and fluid field in peridynamics is based on peridynamic theory. When the bonds gradually break, their equivalent permeability increases accordingly. The water pressure gradient further drives the seepage, which in turn reduces the effective stress of the rock mass, promotes the breaking of more bonds, forms a bidirectional coupling, and thus establishes the coupling equation of the solid field and fluid field.

6. The method for calculating tunnel water inflow based on geophysical parameters and peridynamics according to claim 1, characterized in that: The excavation disturbance simulation divides the excavation process into multiple stress release stages, reduces the non-local force density in steps, and realizes the gradual release of stress.

7. The method for calculating tunnel water inflow based on geophysical parameters and peridynamics according to claim 1, characterized in that: The equivalent node flow method is used to calculate the water inflow of the flow section in the target area in real time, including: The flow section contains a total of multiple material points. For each point, its current water pressure is first read, and then the conductivity of the material point is calculated based on the unit shape and real-time permeability; then, the conductivity of each point is multiplied by the corresponding water pressure, and the algebraic sum of the products of all points in the section is calculated to obtain the instantaneous water inflow through the section at the current moment.

8. The tunnel water inflow calculation system based on geophysical parameters and peri-field dynamics is characterized by: The rock mass area to be calculated for water inflow is taken as the target area, and the calculation steps are as follows: The acquisition module is configured to: acquire geophysical data of a target area in front of the tunnel face; The construction module is configured to: discretize the target area into a number of material points based on the geophysical exploration data, and construct a numerical calculation model of the target area in front of the tunnel face; The simulation module is configured to: perform excavation disturbance simulation based on the initialized numerical calculation model and using the peridynamic solid field and fluid field coupling equations until the excavation process is completed; Among them, in the excavation disturbance simulation, the equivalent node flow method is used to calculate the water inflow of the flow section in the target area in real time.

9. A non-transitory computer-readable storage medium, characterized in that The non-transitory computer-readable storage medium is used to store computer instructions. When the computer instructions are executed by the processor, the method for calculating tunnel water inflow based on geophysical parameters and peri-field dynamics as described in any one of claims 1 to 7 is implemented.

10. An electronic device, characterized in that: include: A processor, a memory and a computer program; wherein the processor is connected to the memory, the computer program is stored in the memory, and when the electronic device is running, the processor executes the computer program stored in the memory to enable the electronic device to implement the tunnel water inflow calculation method based on geophysical parameters and near-field dynamics as described in any one of claims 1 to 7.

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