An evaluation method and system for groundwater flow field disturbance caused by underground structures

Abstract

The application discloses a kind of underground water flow field disturbance evaluation methods and systems caused by underground structure, belong to hydrogeological numerical simulation technical field.The method includes: constructing the numerical benchmark model of groundwater under natural conditions;Define the parameter object of underground structure, describe its geometric size, spatial position, physical property and development condition by parameterization way;Based on the spatial relationship between the parameter object and the discretization grid, automatically identify the affected grid element set, and update the element attribute or boundary condition according to the preset equivalent rule to generate the scene model;On the basis of flow field calculation, particle tracking analysis is performed;By comparing the scene model with the benchmark model, the disturbance degree is quantitatively characterized by using the head change and the retention effect index obtained by particle tracking.The application introduces the seepage path lengthening and the migration time increment as evaluation index, which can comprehensively evaluate the flow field structure reconstruction and environmental risk caused by underground structure.

Description

Technical Field

[0001] This invention belongs to the field of hydrogeological numerical simulation and underground space engineering technology, specifically relating to a method and system for assessing groundwater flow field disturbances caused by underground structures. Background Technology

[0002] With the acceleration of urbanization, underground space has been widely developed and utilized, with numerous underground structures such as subway tunnels, underground stations, underground commercial facilities, and integrated utility tunnels embedded in aquifer systems. These underground structures are typically impermeable or poorly permeable in terms of engineering structure. Their construction and long-term existence will change the original seepage channels and hydrodynamic conditions of groundwater, thereby disturbing the regional groundwater flow field to a certain extent, causing changes in groundwater level, alteration of flow field structure, and potential water environment effects (such as pollutant retention).

[0003] To address the impact of underground structures on groundwater systems, existing technologies primarily employ numerical simulation methods (such as the finite difference method and the finite element method) to analyze groundwater level changes and flow field responses. These methods are typically based on groundwater flow control equations, combined with the hydrogeological conditions of the study area. By simulating the low-permeability or impermeable characteristics of underground structures, they assess the scope and degree of impact of underground structure construction on the groundwater system.

[0004] However, existing technologies still have the following shortcomings in practical applications:

[0005] (1) Low efficiency of multi-scenario simulation. Existing groundwater numerical simulation methods mostly take a single project or a small number of working conditions as the research object. The spatial form, size and burial depth of underground structures usually need to be adjusted manually one by one. It is difficult to realize the rapid construction and batch simulation of multiple types of underground space development scenarios under the same hydrogeological conditions, which limits the ability to conduct systematic comparative analysis of different underground space development schemes.

[0006] (2) The indicators for characterizing groundwater flow field disturbance are too simplistic. When assessing the impact of underground structures, existing technologies usually use changes in groundwater head or water level as the main evaluation indicators. They do not pay enough attention to the characteristics of groundwater flow structure reconstruction, such as deflection of groundwater flow lines, flow around the flow path and changes in seepage path caused by underground structures. Therefore, it is difficult to fully characterize the groundwater flow field disturbance mechanism caused by underground structures.

[0007] (3) The groundwater retention effect is difficult to analyze quantitatively. In existing technologies, the impact of underground structures on the time scale of groundwater flow is often not fully considered. There is a lack of systematic analysis methods for the changes in the length of groundwater flow path and migration time, making it difficult to reveal the impact of changes in groundwater retention time and potential environmental risks caused by underground structures.

[0008] (4) The spatial representation capability of simulation results is limited. Existing technologies mostly present simulation results in the form of two-dimensional planes or partial cross-sections, which makes it difficult to intuitively reflect the three-dimensional spatial relationship between underground structures, aquifer structures and groundwater flow fields, which is not conducive to understanding and application in engineering planning and decision-making processes.

[0009] Therefore, there is an urgent need to propose a groundwater flow field disturbance assessment method and system that can achieve rapid multi-scenario modeling and batch evaluation of underground structures under unified hydrogeological conditions, comprehensively characterize the changes in groundwater head and the reconstructed characteristics of flow structure, and quantitatively analyze the groundwater flow path and residence time, so as to overcome the above-mentioned shortcomings of existing technologies. Summary of the Invention

[0010] Purpose of the invention: The purpose of this invention is to address the shortcomings of existing technologies by providing a method and system for assessing groundwater flow field disturbances caused by underground structures, in order to solve the problems of low efficiency in multi-scenario simulation, limited disturbance characterization indicators, and lack of quantitative assessment methods for groundwater retention effects in existing technologies.

[0011] Technical solution: The method for assessing groundwater flow field disturbance caused by underground structures according to the present invention includes the following steps:

[0012] S1: Construct a numerical benchmark model of groundwater in the study area under natural conditions. The benchmark model includes a discretized grid and corresponding hydrogeological parameters.

[0013] S2: Define underground structure parameter objects The parameter object The geometric dimensions, spatial location, physical properties, and development condition parameters of underground structures are characterized by parametric methods.

[0014] S3: Based on the parameter object The spatial correspondence between the discretized grid and the grid cells is used to identify the set of grid cells affected by underground structures. The set of mesh cells is updated according to a preset equivalence rule. Based on the unit attributes or boundary conditions, generate a groundwater flow field model under the development scenario of underground structures;

[0015] When the parameter object When the geometric dimensions change and exceed the coverage of the current model or fail to meet the preset accuracy requirements, the number of new grid rows and columns required is calculated based on the difference in dimensions before and after the change and the grid resolution. The grid adaptive adjustment and consistency verification are performed, including synchronously updating the model active element array, the top and bottom plate elevation array and the initial head array.

[0016] S4: Numerically solve the groundwater flow field model under the development scenario of the underground structure; when the parameter object When the construction conditions vary over time, define a construction extraction parameter object that includes extraction type, geometric spatial location, affected layer, extraction control parameters, and a time process table. Align its time process with the stress period or calculation period of the model, and map it to the mesh element to generate unsteady source and sink terms / boundary conditions;

[0017] S5: Based on the velocity field data, perform particle tracking analysis to extract information on groundwater streamline path, seepage path length, and migration time.

[0018] S6: Compare the calculation results of the groundwater flow field model under the development scenario of the underground structures with the calculation results of the groundwater numerical benchmark model, and comprehensively utilize the hydraulic head change index and the retention effect index obtained by the particle tracking analysis to quantitatively characterize the degree of disturbance of the underground structures on the groundwater flow field; the retention effect index includes at least the seepage path extension and migration time increment; and based on the parameter object The spatial location is used to delineate key evaluation areas, and the cumulative residence time of particles or the proportion of particles that have not flowed out in the area is calculated to generate statistical assessment results of the retention risk.

[0019] Furthermore, the present invention also provides a system for assessing groundwater flow field disturbances caused by underground structures, comprising:

[0020] The benchmark modeling module is used to construct a numerical benchmark model of groundwater in the study area under natural conditions.

[0021] The parameterized driver module is used to receive parameter objects describing underground structures. and construction extraction parameters ;

[0022] The model mapping and update module is used to automatically identify the affected grid cell set based on the parameter object, perform grid adaptive adjustment and consistency verification, and update cell attributes or boundary conditions according to preset equivalent rules to generate a groundwater flow field model under the development scenario of underground structures.

[0023] The numerical solution and tracking module is used to call the computation engine to solve the flow field and perform particle tracking.

[0024] The comprehensive assessment module is used to compare the calculation results of the groundwater flow field model under the development scenario of underground structures with the groundwater numerical benchmark model, and to calculate the water level disturbance index, flow structure reconstruction index and retention risk statistical assessment results.

[0025] Beneficial effects: Compared with the prior art, the advantages of the present invention are as follows:

[0026] This invention introduces particle tracking analysis in addition to water level change indicators and constructs retention effect indicators such as seepage path extension and migration time increment, thereby enabling quantitative characterization of groundwater migration timescale changes caused by underground structures and providing a basis for analyzing the risk of groundwater retention caused by flow velocity changes.

[0027] Parametric representation of structures (objects) The automatic mesh mapping technology enables the geometric properties of underground structures to automatically correspond to the discrete mesh of the numerical model, thereby realizing the automatic identification of affected units and automatic model updates. This avoids tedious manual mesh modifications, greatly improves the efficiency of scheme comparison, and eliminates topological errors introduced by manual operation.

[0028] This invention can automatically calculate the required number of new grid rows and columns and perform parameter interpolation based on changes in the scale of the structure. This adaptive mechanism provides sufficient model range for large-scale structure simulations and meets the required mesh accuracy for small-scale simulations, achieving a balance between computational cost and accuracy.

[0029] By setting equivalent rules to characterize the function of different types of underground structures, it is possible to simulate the obstruction effect of static impermeable or weakly permeable structures on groundwater flow, and also to characterize dynamic conditions such as construction dewatering and drainage through time-varying source and sink terms, thereby supporting the analysis of groundwater flow field response during engineering construction and operation.

[0030] This invention can output three-dimensional visualized streamline trajectories and disturbance distribution maps, intuitively showing the three-dimensional spatial relationship between underground structures, aquifer structures and flow fields, providing quantitative scientific basis for underground space planning, design optimization and environmental risk management. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the overall process of the method provided in the embodiments of the present invention;

[0032] Figure 2 This is a schematic diagram illustrating the parametric description of underground structures and the automatic identification of the set of influencing elements in an embodiment of the present invention; Detailed Implementation

[0033] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings, but the scope of protection of the present invention is not limited to the embodiments described.

[0034] Example 1: This example provides a method for assessing groundwater flow field disturbances caused by underground structures. This method can be implemented based on a groundwater numerical simulation model and scripted modeling technology. In a preferred embodiment, MODFLOW is used for numerical calculation of the groundwater flow field, FloPy is used for model construction, batch scenario generation, parameter updating, and result analysis, and MODPATH is preferably used for particle tracking analysis and ParaView for spatial display of results. Through these methods, a workflow for assessing disturbances to underground structures in multiple scenarios can be realized. This workflow is used to sequentially implement the following processes under unified hydrogeological conditions: baseline model construction → parameterized object of the structure → automatic identification of the set of influencing grid cells → updating the scene model with preset equivalent rules → batch solution of multiple scenarios → output of disturbance assessment indicators and particle tracking results → comprehensive evaluation and visualization.

[0035] like Figure 1 As shown, the overall process of the method provided in this embodiment is divided into four stages: preprocessing, simulation calculation, evaluation, and output. Specifically, it includes the following detailed steps:

[0036] 1. Input Data and Standardization Stage (Preprocessing)

[0037] Before building the model, data preparation is performed first. This involves acquiring a three-dimensional geological model of the study area, hydrogeological parameter fields (permeability coefficient, specific yield, etc.), boundary conditions, and source-sink term data (such as rainfall infiltration and river boundaries).

[0038] Spatial data from different sources are unified to the same projected coordinate system and a unified spatial reference datum. To address the inconsistency between the 3D geological model and the numerical model's mesh stratigraphy, stratigraphic alignment and meshing are performed to map the stratigraphic lithological structure to the model mesh, forming a structured input dataset.

[0039] 2. Pre-processing stage (S1-S2)

[0040] S1: Constructing a numerical benchmark model for groundwater

[0041] The study area's topographic conditions, stratigraphic structure, hydrogeological parameters (permeability coefficient, water storage rate, etc.), boundary conditions, and observational data were obtained. A conceptual model of regional groundwater flow was established using groundwater numerical simulation software, and spatial discretization (grid generation) was performed to construct a groundwater numerical benchmark model under natural conditions. This benchmark model was used to simulate the natural groundwater flow field under conditions without the influence of underground structures, serving as a reference model for subsequent scenario model comparison and analysis.

[0042] In this step, an initial model of the natural working conditions unaffected by underground structures is established.

[0043] Conceptual model numericalization: Transform the hydrogeological conceptual model into a numerical discrete model, defining the rows, columns, number of layers, and size of the grid.

[0044] Parameter assignment and boundary setting: Assign the standardized hydrogeological parameters to the corresponding grid cells, and set the model boundaries (such as constant head boundary, flow boundary) and source and sink terms.

[0045] Model identification and verification: The baseline model is calibrated and verified using historical water level and flow data to improve the reliability of the baseline model in representing the characteristics of groundwater flow field under natural conditions and to provide a reference benchmark for subsequent scenario comparison.

[0046] S2: Parametric Definition of Structures

[0047] Unlike traditional methods that directly modify attributes of individual grid cells, this embodiment uses a parametric input method to define underground structure parameter objects. Taking a regular rectangular structure as an example, the parameter object... The following parameter elements may be included:

[0048] (1) Geometric parameters: Structure type (rectangular / cylindrical / polygonal / linear tunnel section), length, width, and height;

[0049] (2) Spatial location parameters: center coordinates azimuth angle Burial depth or top / bottom plate elevation;

[0050] (3) Physical property parameters: equivalent permeability, barrier properties, water conductivity and drainage capacity parameters of underground structures;

[0051] (4) Development conditions parameters: development method, development stratum and construction operation conditions, wherein the development method includes excavation and replacement, water-stop curtain, drainage gallery, high water-conductivity belt, construction dewatering or pumping, etc., and the development stratum includes specified strata or specified depth range.

[0052] 3. Simulation Calculation Stage (S3-S4)

[0053] S3: Automatic Mapping and Equivalent Rule Update

[0054] like Figure 2 As shown, this step automatically converts the "parameter object" into the "numerical model input," specifically including:

[0055] (1) Mesh adaptive adjustment

[0056] When changes in structure scale lead to expansion of the model domain or changes in local accuracy requirements, a discrete update strategy is preferred. For example, when the structure length is adjusted from L1 to L2 (e.g., 200 m → 300 m) and the model domain needs to be expanded, the new column is automatically calculated:

[0057]

[0058] in, For grid column width, This indicates rounding up to the nearest integer.

[0059] Based on the calculated number of new rows and columns, the discrete parameters of the model are updated, and the parameter fields of the new regions are interpolated or assigned values ​​by region. At the same time, the active unit array (e.g., IBOUND), the initial head array, the boundary condition corresponding array, and the source-sink term position mapping relationship are updated simultaneously to ensure the consistency between the model structure and physical quantities.

[0060] (1) Update the model discretization parameters

[0061] Update discrete parameters based on the number of newly added rows and columns, preferably including:

[0062] Update grid dimensions: For example: (or );

[0063] Update grid size array: Expand (or The array can be filled with the original grid size or the preset size in the newly added area;

[0064] Update model space extent: Synchronously update the model space extent according to the expansion direction. (For example: synchronously update the model origin and circumference extent);

[0065] Update top / bottom interface arrays: Expand the array dimensions of top and bottom to match the updated ones. , , Consistent.

[0066] (2) Expansion and assignment of new regional parameter fields

[0067] right , , Spatial fields such as initial head and partition coding are assigned values ​​to newly added regions using partition inheritance, spatial interpolation, or boundary extension methods to ensure that the dimensions of each parameter field array are consistent with the updated ones. Totally consistent.

[0068] (3) Synchronously update the mapping of active units, initial head and boundary source and sink terms.

[0069] To ensure physical consistency, the system synchronously performs the following updates on newly added grid regions:

[0070] Update the active unit array: Newly added regions can be set as active or inactive units depending on whether they belong to the aquifer distribution range; if the newly added region contains uncalcifiable areas (such as missing strata outside the domain), it is set as an inactive unit; existing inactive areas remain unchanged, and the deactivation or blocking settings of the structures affecting the units are still effective after the update.

[0071] Initial head update: The initial head for new areas can be generated by interpolation / extrapolation of the reference head field, or according to rules such as boundary head / topographical water level; ensuring that the initial head array is consistent with... , , Match and set inactive units to invalid values ​​or fill them as required by the model.

[0072] Boundary conditions and source / sink term remapping: The system saves the geometric objects (river lines / surfaces, supply polygons, well points / drainage ranges, etc.) or raster representations of the boundaries and sources / sinks. After the mesh is updated, it recalculates the set of net cells and writes it to the corresponding package file: Surface supply: The intersection of the supply region polygons with the mesh is calculated to generate a new supply array; River / lake boundaries: The boundary cell indices are redefined based on the intersection of the boundary lines with the mesh, while maintaining the boundary water level and water conduction parameters unchanged or extending according to preset rules; Wells and drainage: The well locations or drainage ranges are relocated to new locations. It also removes or moves entries that fall into inactive cells to the nearest active cell.

[0073] (4) Consistency check (to ensure correct updates)

[0074] After the mesh update is completed, the system preferentially performs a consistency check to ensure that the model structure and physical quantities are consistent:

[0075] Dimensional consistency: Check the dimensions of all arrays (top / botm, active cell array, parameter field array, boundary array) and... , , Consistent;

[0076] Index validity: Check that all boundary, well, and drainage entries fall within the valid range and that the corresponding cells are active cells;

[0077] Topology consistency: Check that the set of elements affected by the structure Ω(S) remains correctly located after the update and is consistent with the equivalent rules used;

[0078] Mass conservation check: Compare the overall water balance or boundary flux magnitude of the baseline scenario before and after the update. If an abnormal change occurs, an alarm will be triggered and a list of problematic units will be output.

[0079] The above process is based on the updated version. / To ensure consistency in the equivalent settings of the model structure, parameter fields, boundary sources and sinks, and structures after mesh expansion, the mapping relationship between array dimensions and indices is reconstructed synchronously. When only local refinement is required, nested sub-models or local mesh refinement strategies are preferred implementation methods.

[0080] (2) Identification of Influencing Units

[0081] Based on structure parameter objects The spatial coordinate and model discrete mesh indexing system automatically identifies the sets of mesh elements that overlap or intersect with the structure entity in space. In a preferred embodiment, one or a combination of the following criteria can be used to determine the influencing element. Element center point criterion: If the element center point falls within the structure volume (or planar projection and vertical range), it is determined to be an influencing element; Voxel intersection criterion: If the grid element voxel intersects with the structure volume in space, the element is determined to be an influencing element.

[0082] When the structure has a non-zero orientation angle ( When the tunnel is a linear tunnel section, coordinate rotation transformation and segmented mapping along the path are used to support the automatic identification of rotating bodies and linear structures.

[0083] (3) Application of equivalence rules

[0084] System reads parameter object The physical properties and development method parameters are used to call preset equivalent rules to identify the set of units. Update the attributes of the boundary and related boundaries:

[0085] The equivalent rule for complete isolation: applies to the main body of a station, solid foundation pits, and other underground structures that can be approximated as completely blocking groundwater flow. For such structures, The corresponding cells within the MODFLOW array are marked as inactive cells or set as cells of a specified type, so that they no longer participate in groundwater flow calculations, and the relevant hydraulic parameters can be updated synchronously to maintain physical consistency. In a preferred embodiment, the IBOUND value of the corresponding cell can be set to 0 in MODFLOW.

[0086] Equivalent rule for weakly permeable barriers: Applicable to diaphragm walls, cutoff walls, and other underground structures with barrier functions. For these structures, parameter reduction or interface barrier methods are used: The permeability coefficient within the region is reduced to a preset ratio ( Alternatively, a horizontal flow barrier (HFB) can be automatically set at the unit interface to simulate the thin-walled water-blocking effect by defining the interface resistance factor.

[0087] Water-conducting-drainage equivalent rule: Applicable to drainage galleries, high water-conductivity zones, and other underground structures with water-conducting or drainage functions. For such structures, the permeability coefficient of the corresponding unit within Ω(S) can be increased, for example, by setting: in Internal Furthermore, drainage boundaries can be superimposed to characterize its drainage capacity and runoff process. In a preferred embodiment, this can be implemented using a DRN package or a GHB package.

[0088] Time-varying pumping equivalent rules: Applicable to time-varying operating conditions such as construction dewatering systems, well group pumping systems, and dynamic drainage systems during operation. For these types of operating conditions, source and sink inputs corresponding to well groups or drainage units can be automatically generated, and flow rate or control water level changes with time or operating conditions can be supported to simulate the impact of dynamic pumping on the groundwater flow field. In a preferred embodiment, this can be implemented through the WEL package or the DRN package.

[0089] The construction dewatering or pumping system is preferably input as a parameterized object 𝐷. This parameterized object includes at least: pumping / drainage type (well group pumping or drainage unit), spatial location (well coordinates or drainage range), operational stratum or top and bottom elevations of the screen section, pumping / drainage control parameters (well flow rate or drainage control water level), and time process (construction start and end times and segmented work condition tables). The system automatically maps the spatial elements of 𝐷 to the model mesh, obtaining the corresponding set of mesh element indices. The well group pumping system automatically locates the corresponding well location and formation. The drainage unit obtains multiple [units] by intersecting the drainage range with the grid. .

[0090] The system aligns the segmented working condition table with the model stress period or calculation period, and determines the corresponding pumping flow rate or drainage control water level for each stress period or calculation period, forming an input data set organized by time period. When using the WEL package, for... The internal unit writes the pumping traffic for the corresponding time period; when using DRN packets, for The internal unit writes drainage control water level and water conduction capacity parameters. The water conduction capacity parameters can be preset from drainage structure design parameters, calculated from empirical coefficients and unit contact area or equivalent length, or input as a calibrable parameter. When the well screen section spans multiple layers, the pumping flow rate can be allocated according to the effective thickness or permeability weight of the screen section in each layer. During automatic generation, consistency verification is preferably performed, including: writing source and sink items only to active units, merging or deduplicating duplicate entries, and handling conflicts with structure barrier settings according to preset priority rules. In a preferred embodiment, the priority rules may include: priority for inactive units (inactive units are not written to source and sink); interface barriers can coexist with source and sink; when a source and sink unit falls into an inactive unit, it is removed or moved to the nearest active unit, thereby achieving automatic writing and updating of the construction dewatering or pumping system in multi-scenario batch simulations.

[0091] S4: Numerical Simulation of Groundwater Flow Field

[0092] Under a unified hydrogeological benchmark, different sets of structural parameters are considered. Batch numerical solutions are performed, where each parameter object corresponds to different structure layouts, scales, burial depths, orientations, or action modes, thereby obtaining groundwater head distribution and seepage field data under various scenarios.

[0093] S5: Groundwater Flow Path and Retention Time Analysis

[0094] Based on flow field calculations, a particle tracking model is preferably used for analysis; in a preferred embodiment, MODPATH can be used. Tracer particles are released in both the baseline model and the scenario model, and trajectory information of the particles as they pass through preset regions, preset cross-sections, or reach termination boundaries is extracted. Relevant path and time indices are then calculated. The streamline path characterizes the spatial trajectory of the particles; the migration time characterizes the time it takes for a particle to move from its release point to the termination boundary, preset cross-section, or when the termination condition is met.

[0095] Based on particle tracking results, information such as groundwater streamline paths, seepage path lengths, and migration times can be extracted. This information can then be used to analyze streamline deflection, bypass phenomena, and seepage path elongation characteristics caused by underground structures. Furthermore, statistical analysis of the migration time distribution can be performed to characterize changes in groundwater migration timescales and retention effects.

[0096] (1) Calculation of streamline path based on groundwater flow field results

[0097] The water head is obtained from the calculation of the groundwater flow field. ;

[0098] By Darcy's Law: = ;

[0099] Particle tracking preferably uses the pore water surface velocity as the motion velocity, which can be expressed as:

[0100] in, Effective porosity.

[0101] (2) Expression for streamline path:

[0102]

[0103] in, Indicates the location where the particle was released. This indicates the particle release time. The streamline path can be obtained by iteratively advancing according to a preset step size and satisfying the termination condition. .

[0104] The following metrics are calculated based on the trajectory point sequence:

[0105] Streamline path: the spatial trajectory of a particle or its discrete point sequence ;

[0106] Seepage path length: trajectory arc length, preferably calculated using discrete accumulation.

[0107]

[0108] in, The discrete point index of the trajectory. Decrease the total number of discrete points on the particle's trajectory by 1.

[0109] (3) Expression for migration time

[0110] The migration time is the time difference between release and reaching the termination boundary (or meeting the termination condition):

[0111]

[0112] in, For the moment of release, This is the termination time.

[0113] Through the natural and constructed scenarios and Perform difference or ratio comparisons, and for multi-particle... By conducting statistical summaries (mean, median, quantiles, etc.), the streamline deflection, flow around, seepage path extension, and migration time distribution changes caused by underground structures can be quantitatively characterized, thus using the migration time statistics as an evaluation quantity or equivalent indicator of changes in groundwater retention effect.

[0114] S6: Particle Tracking and Comprehensive Evaluation

[0115] The scenario model results are compared and analyzed with the baseline model results, and the following perturbation evaluation indicators are output:

[0116] (1) Water level disturbance index: head difference field Statistical indicators such as maximum drawdown, radius of influence, and area of ​​equal drawdown;

[0117] (2) Flux or discharge changes: changes in river exchange volume, changes in boundary inflow and outflow, and changes in flux at the preset profile;

[0118] (3) Flow structure reconstruction and retention effect index: The streamline path, seepage path length and migration time are obtained by particle tracking, and the streamline deflection, flow around the flow, path extension and migration time variation characteristics are analyzed accordingly.

[0119] In the comprehensive evaluation phase, based on the particle tracking results obtained from S5, the differences in particle trajectories between the natural baseline scenario and the underground structure scenario can be compared and analyzed, thereby quantitatively characterizing streamline deflection, flow around phenomena, seepage path extension, and migration time variation.

[0120] Consistent particle release settings are used in both the natural baseline scenario and the structure scenario, including release location or cross-section, particle number and distribution, release time, and termination boundary (or termination condition). Forward tracking is performed on the same set of release points. Preferably, a correspondence is established using the same release point number. Based on this, the path length and migration time are calculated for each particle, and the differences and ratios are compared with the corresponding results in the baseline scenario to obtain the path extension, migration time increment, and their relative rate of change. The path length is obtained by accumulating the distances between adjacent trajectory points in the particle trajectory output, and the migration time is obtained from the time difference between the particle release time and the time it reaches the termination boundary (or meets the termination condition).

[0121] Statistical summaries of all particle results (such as mean, median, quantiles, and extreme values) are generated to form quantitative results of changes in migration time distribution and path length distribution. Evaluation areas can be set up in the vicinity of the structure to count the cumulative residence time of particles in the area or the proportion of particles that do not reach the termination boundary within a limited time, so as to quantify the spatial range and intensity of retention enhancement and flow around effect.

[0122] By changing the equivalent width, burial depth, orientation, and barrier strength parameters of the structure, sensitivity analysis or statistical comparison can be carried out to identify the key structure parameters that control the changes in disturbance intensity and residence time.

[0123] Specifically, under the premise of keeping the unified hydrogeological conditions and boundary source-sink terms unchanged, the equivalent width W, burial depth z, strike θ and barrier strength parameter α are selected as the parameters to be analyzed, and the feasible value range and dispersion level of each parameter are set (e.g., low / medium / high three levels or disturbance according to a preset ratio).

[0124] In a preferred embodiment, sensitivity analysis is performed using a single-factor perturbation approach: all other parameters are fixed as baseline values, and only one parameter is changed to generate corresponding parameter scenario groups. For each scenario, the identification of influencing unit sets, updating of equivalent rules, generation of scenario models, and numerical solution are automatically performed. For each scenario, perturbation intensity indicators (e.g., maximum head change, exceeding threshold influence range, boundary flux change, etc.) and migration time indicators (e.g., mean, median, quantile changes in migration time, changes in the proportion of particles not reaching the termination boundary within a limited time, changes in cumulative residence time within the evaluation area, etc.) are output and compared with the baseline scenario results. Finally, the influence of parameters is preferably quantified and ranked using methods such as normalized change amplitude, range comparison, or correlation analysis, thereby identifying key structural parameters and their sensitive ranges that significantly contribute to perturbation intensity and migration time changes, providing a basis for scheme comparison and parameter control.

[0125] Taking a rectangular structure as an example, the equivalent width W, burial depth z, orientation θ, and barrier strength parameter α are selected as sensitivity analysis parameters. First, a baseline scenario is established. The baseline results (perturbation intensity index and migration time statistics) were obtained by solving the problem. Then, while keeping other parameters constant, parameter scenario groups were constructed using a single-factor perturbation method:

[0126] Width group: This yields three scenarios;

[0127] Burial depth group: This yields three scenarios;

[0128] Heading Group: This yields four scenarios;

[0129] Barrier strength group: This yields three scenarios.

[0130] Automatically execute the "influence unit set" for each scenario. The process involves "identification → equivalent rule update → scene model generation → numerical solution → particle tracking," outputting disturbance intensity indices (e.g., maximum head change, over-threshold influence area, boundary flux change) and migration time indices (e.g., median migration time increment, quantile change, proportion of particles not reaching the termination boundary within a specified time). Finally, the magnitude of change of each indices relative to the baseline scenario is used as a sensitivity measure. Calculate the normalized sensitivity or range of "indicator change range - parameter change range" separately, and sort them by sensitivity. The parameters with the highest sensitivity are identified as key structural parameters that control the change in disturbance intensity and migration time. At the same time, the sensitive range can be identified based on the inflection point or threshold of the indicator as the parameter changes.

[0131] (4) Risk zoning and comparative evaluation: Based on preset evaluation thresholds, such as allowable depth thresholds, sensitive area constraints, or migration time increment thresholds, the degree of groundwater flow field disturbance can be graded (e.g., slight, moderate, severe). Combined with sensitivity analysis, key structural parameters that control flow field disturbance can be identified, such as whether key permeable layers are blocked, the magnitude of the barrier strength and the hydraulic cut-off effect and retention enhancement effect caused by it, thereby providing a basis for underground space engineering planning and scheme selection.

[0132] 5. Results Output and Publication Stage

[0133] Comparison charts, profiles, and statistical tables: Automatically generate contour maps of water level differences, flow velocity vector profiles, and statistical tables of evaluation indicators.

[0134] 3D visualization files: The output results of various scenarios (such as head, velocity, flow rate and particle trajectory data) are processed and converted into formats such as VTK, VTU, and CSV, and then imported into visualization software to construct 3D visualization scenes; the spatial relationship between underground structures, aquifer structures and groundwater flow fields is displayed through rotation, slicing, profile and isosurface methods.

[0135] Decision support documentation: Automatically summarizes key indicators and generates scenario simulation reports, which include key charts and comparative conclusions of indicator summaries.

[0136] Example 2: This example provides a system for assessing groundwater flow field disturbances caused by underground structures. The system may include a memory, a processor, and a computer program stored in the memory. When executed by the processor, the computer program performs logical operations on the following functional modules:

[0137] Data Management Module: Imports 3D geological models, hydrogeological parameter fields, and observation data; performs coordinate unification, layer alignment, and discrete grid processing to provide a unified spatial reference for subsequent simulations.

[0138] Benchmark Modeling Module: Establishes a benchmark numerical model under natural conditions, configures the initial flow field and boundary conditions, and (optionally) completes the calibration and verification of the benchmark model based on observation data.

[0139] Scenario parameterization module: Provides an interactive interface to receive structure parameter objects. (Including geometric dimensions, spatial location, physical properties and development conditions, etc.), and automatically generate a variety of underground space development scenario combinations in combination with preset rules.

[0140] Mesh mapping module: Performs spatial coordinate transformation on structures and automatically identifies the set of mesh cells affected by the structures. It also establishes a spatial index. When changes in the size or location of structures cause insufficient accuracy of the original mesh or limitations in the model range, it automatically calculates the required row and column expansion or densification parameters, and performs parameter field interpolation and assignment on the newly added areas to ensure the physical consistency of the model discretization.

[0141] Package update module: Based on preset equivalence rules, automatically update the core input package of the numerical model (including but not limited to the active cell array, permeability parameter array, interface barrier input, and source-sink term data), and automatically perform logical checks during the writing process (e.g., ensuring that the pumping well is not located in a dead cell closed by the stop curtain, and ensuring that the boundary conditions are compatible with the new mesh topology) to prevent model running errors.

[0142] The solution scheduling module parses the scenario combination queue, calls the numerical module for batch solutions, and supports multi-threaded or multi-process parallel management to improve computational efficiency.

[0143] Indicator evaluation module: Based on the calculation of water head and flow field, it integrates particle tracking algorithm to calculate key elements such as groundwater streamline trajectory, seepage path length and migration time.

[0144] Visualization and Reporting Module: Automatically extracts the head disturbance field, calculates evaluation indicators such as streamline deflection and residence time increment; evaluates the disturbance level by region based on preset thresholds, and identifies key structural parameters that control the disturbance intensity; exports simulation results to a common format (such as VTK / CSV), generates a 3D visualization scene containing structural entities and flow field response, and automatically compiles a scenario analysis report containing statistical charts and comparative conclusions.

[0145] Those skilled in the art will understand that all or part of the steps in the methods of the above embodiments can be implemented by computer program instructions to related hardware. The computer program can be stored in a computer-readable storage medium and, when executed, implements all or part of the processes in the methods of the above embodiments.

[0146] As described above, although the invention has been shown and described with reference to specific preferred embodiments, it should not be construed as limiting the invention itself. Various changes in form and detail may be made without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. A method for assessing groundwater flow field disturbances caused by underground structures, characterized in that, Includes the following steps: A numerical benchmark model of groundwater in the study area under natural conditions is constructed. The benchmark model includes a discretized grid and corresponding hydrogeological parameters. Define underground structure parameter objects The parameter object The geometric dimensions, spatial location, physical properties, and development condition parameters of underground structures are characterized by parametric methods. Based on the parameter object The spatial correspondence between the discretized grid and the grid cells is used to identify the set of grid cells affected by underground structures. The set of mesh cells is updated according to a preset equivalence rule. Based on the unit attributes or boundary conditions, generate a groundwater flow field model under the development scenario of underground structures; Numerical solutions were performed on the groundwater numerical benchmark model and the groundwater flow field model under the underground structure development scenario to obtain the corresponding groundwater head distribution and velocity field data. Based on the velocity field data, particle tracking analysis is performed to extract groundwater streamline path, seepage path length, and migration time information. The particle tracking analysis includes: The water head is obtained from the calculation of the groundwater flow field. According to Darcy's Law: ; Particle tracking uses the pore water surface velocity as the motion velocity, which is expressed as: ,in, Effective porosity; The expression for the streamline path is: ,in, Indicates the location where the particle was released. The streamline path is obtained by iteratively advancing at a preset step size and satisfying a termination condition, representing the particle release time. ; The seepage path length is the arc length of the trajectory, calculated using discrete accumulation: ,in, The discrete point index of the trajectory. Subtract 1 from the total number of discrete points on the particle's trajectory; The migration time information is the time difference from release to reaching the termination boundary or meeting the termination condition: ,in, For the moment of release, The termination time; The calculation results of the groundwater flow field model under the development scenario of the underground structure are compared with the calculation results of the groundwater numerical benchmark model to calculate the groundwater flow field disturbance assessment index, so as to quantitatively characterize the degree of groundwater flow field disturbance caused by the underground structure; wherein, the groundwater flow field disturbance assessment index includes at least the water level disturbance index and the retention effect index, and the retention effect index includes at least the seepage path extension and the migration time increment.

2. The method for assessing groundwater flow field disturbance caused by underground structures according to claim 1, characterized in that, The mesh cell set is updated according to a preset equivalent rule. The element properties or boundary conditions include: When the parameter object When including construction conditions that vary over time, define the construction extraction parameter object. The construction extraction parameter object It includes the extraction type, geometric spatial location, affected layer, extraction control parameters, and time process table; According to the construction extraction parameter object Perform mesh mapping at the spatial location to obtain the corresponding mesh cell index; Align the time process table with the stress period or calculation period of the numerical model, and within each stress period or calculation period, write source / sink terms / boundary conditions to the corresponding grid cell index according to the extraction control parameters to simulate the unsteady flow changes during construction precipitation or drainage.

3. The method for assessing groundwater flow field disturbance caused by underground structures according to claim 1, characterized in that, The method also includes a mesh adaptive adjustment step based on changes in structure scale: When the parameter object When the geometric dimensions change and cause the model to exceed the coverage of the current model or fail to meet the preset accuracy requirements, the number of new grid rows and columns required is calculated based on the difference in dimensions before and after the change and the grid resolution. The discrete parameters of the model are reconstructed based on the newly added number of grid rows and columns, and the hydrogeological parameters of the newly added area are interpolated and assigned, while the active unit array, top and bottom plate elevation array and initial hydraulic head array of the model are updated simultaneously. After the grid update is complete, a consistency check is performed, which includes at least checking the matching of all parameter array dimensions and the topological validity of the building-affected cell index.

4. The method for assessing groundwater flow field disturbance caused by underground structures according to claim 1, characterized in that, The parameter object The parameters included must include at least: structure type, length, width, height, center coordinates, orientation angle, burial depth or top and bottom plate elevation.

5. The method for assessing groundwater flow field disturbance caused by underground structures according to claim 4, characterized in that, The set of grid cells identified as being affected by underground structures. Includes the following steps: When the parameter object When there is a non-zero orientation angle or a non-orthogonal geometry, perform coordinate rotation transformation or piecewise mapping along the center path to project the geometry of the structure into the discretized mesh; By employing the element center point criterion or voxel intersection criterion, a mapping relationship from the geometric space of the structure to the grid element index is constructed, thereby determining the set of grid elements affected by the underground structure. .

6. The method for assessing groundwater flow field disturbance caused by underground structures according to claim 1, characterized in that, The equivalent rule also includes performing at least one of the following operations: When the physical property of the parameter object S is an impermeable structure, the mesh cell set... The cells in the text are marked as inactive cells; When the physical property is a weakly permeable curtain, the mesh cell set is... The unit permeability coefficient is reduced to a preset barrier coefficient, or a horizontal flow barrier boundary is set at the interface of the grid unit set. When the parameter object When the grid cell set includes construction drainage or high water conductivity channels, The source-sink term boundary conditions are superimposed or the permeability coefficient of the corresponding cell is increased; when the superimposed source-sink term / boundary condition falls into an inactive cell, a removal operation is performed or it is moved to the nearest active cell.

7. The method for assessing groundwater flow field disturbance caused by underground structures according to claim 1, characterized in that, The method further includes a multi-scenario batch simulation step, which includes: Under a unified hydrogeological benchmark, a parameter set containing parameter objects of multiple different underground structures is constructed. Each parameter object corresponds to different structural layouts, scales, burial depths, orientations, or barrier strength parameters. The system automatically loops through the steps of mesh mapping, model updating, numerical solution, and index extraction, generating and solving the corresponding set of scenario models in batches. Output the groundwater flow field disturbance assessment results of each scenario model relative to the benchmark model for scheme comparison.

8. The method for assessing groundwater flow field disturbance caused by underground structures according to claim 7, characterized in that, The method also includes a sensitivity analysis step: The equivalent width, burial depth, orientation, and barrier strength parameters of the structure are selected as the parameters to be analyzed, and parameter scenario groups are constructed by single-factor perturbation or multi-factor combined perturbation. The changes in evaluation indices for each parameter scenario group relative to the baseline model are calculated and normalized and sorted to identify key structural parameters that control the intensity of flow field disturbances and migration time.

9. The method for assessing groundwater flow field disturbance caused by underground structures according to claim 1, characterized in that, The groundwater flow field disturbance assessment indicators include: Water level disturbance indicators, including head difference field, maximum drawdown and radius of influence; The flow structure reconstruction index includes streamline deflection, flow path elongation rate, and residence time increment; wherein, the residence time increment is obtained by comparing the difference in migration time of the same particle when passing through a preset region, preset cross section, or reaching the model boundary in the baseline model and the scene model. The method also includes a stay risk statistical assessment step: based on the parameter object The spatial location is used to delineate key evaluation areas affected by the structure in the scene model; the particle tracking results are statistically analyzed to calculate the cumulative residence time of particles in the key evaluation area, or to calculate the proportion of particles that fail to flow out of the key evaluation area or fail to reach the model boundary within a preset time limit; the spatial range and intensity of the groundwater retention effect caused by the underground structure are quantitatively characterized by the cumulative residence time or particle proportion.

10. A system for assessing groundwater flow field disturbances caused by underground structures, characterized in that, include: The benchmark modeling module is used to construct a numerical benchmark model of groundwater in the study area under natural conditions. The benchmark model includes a discretized grid and hydrogeological parameters. The parameterized driver module is used to receive parameter objects describing underground structures. The parameter object Includes the geometric dimensions, spatial location, physical properties, and development condition parameters of the structure; The model mapping and update module is used to map and update the parameters based on the parameter object. Automatically identify the affected set of grid cells And update the cell attributes or boundary conditions in the set of grid cells Ω(S) according to the preset equivalent rules to generate a groundwater flow field model under the development scenario of underground structures. The numerical solution and tracing module is used to solve the groundwater numerical benchmark model and the groundwater flow field model under the underground structure development scenario, respectively, to obtain head distribution and velocity field data. Based on this, particle tracing analysis is performed to extract streamline path, seepage path length, and migration time information. Specifically, the groundwater flow field calculation yields the head... According to Darcy's Law: Particle tracking uses the pore water surface velocity as the motion velocity, which is expressed as: ,in, The effective porosity; the expression for the streamline path is: ,in, Indicates the location where the particle was released. The streamline path is obtained by iteratively advancing at a preset step size and satisfying a termination condition, representing the particle release time. ; Calculate the seepage path length based on the trajectory point sequence: ,in, The discrete point index of the trajectory. The total number of discrete points on the particle trajectory is reduced by 1; the migration time is the time difference from release to reaching the termination boundary or satisfying the termination condition. ,in, For the moment of release, The termination time; The comprehensive evaluation module compares the calculation results of the scenario model with those of the benchmark model, calculating water level disturbance indices including the head difference field and maximum drawdown, as well as flow structure reconstruction indices including streamline deflection, flow path elongation, and residence time increment; and based on the parameter objects... The spatial location is used to delineate key evaluation areas, and the cumulative residence time of particles or the proportion of particles that have not flowed out in the area is calculated to generate statistical assessment results of the retention risk.

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