Hydropower underground engineering support design method and system based on discrete element model

Abstract

The invention discloses a hydroelectric underground engineering support design method and system based on a discrete element model, and relates to the technical field of geotechnical engineering.The method comprises the steps that a three-dimensional chamber excavation model is built according to chamber types and chamber space parameter information in combination with key engineering geological parameters; based on the supporting parameters corresponding to the chamber excavation mode, chamber excavation supporting is dynamically simulated through the discrete element model, and a chamber supporting scheme is generated; and determining a judgment standard taking a plurality of set parameters as evaluation indexes, and constructing a support scheme optimization judgment system to obtain an optimal support scheme. The optimal scheme can be finally screened out, the design efficiency is improved, and the construction cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of geotechnical engineering technology, and in particular to a method and system for support design of underground hydropower projects based on discrete element model. Background Technology

[0002] The tunnel support system mainly consists of two parts: the surrounding rock and the support. The formation of the tunnel support system is achieved through a specific construction process or mechanical control. Therefore, tunnel support design is essentially the design of controlling the changes in the mechanical state of the tunnel. Due to limitations in tunnel support design and the means of obtaining surrounding rock information, tunnel support design has long struggled to achieve ideal design results. Specifically, current commonly used tunnel support design methods typically rely on the single information of surrounding rock grade determination, failing to consider the impact of construction information on the support design, resulting in insufficient precision and targeting of the tunnel support design for construction. While some existing technologies utilize orthogonal experimental design methods to improve efficiency in determining the optimal support scheme, the analysis and optimization of experimental results generally rely on intuitive analysis methods. However, the interactions between factors and the nonlinear influence of factor levels on the experimental results can easily lead to suboptimal support schemes, affecting the actual support effect. Summary of the Invention

[0003] To address the shortcomings of existing technologies, the purpose of this invention is to provide a method and system for the support design of underground hydropower projects based on discrete element models, which can ultimately select the optimal solution, improve design efficiency, and reduce construction costs.

[0004] To achieve the above objectives, the present invention is implemented through the following technical solution: In a first aspect, embodiments of the present invention provide a support design method for underground hydropower engineering based on a discrete element model, comprising: Based on the chamber type and spatial parameters, a three-dimensional chamber excavation model is constructed in conjunction with key engineering geological parameters. Based on the support parameters corresponding to the chamber excavation method, the discrete element model is used to dynamically simulate the chamber excavation support and generate a chamber support scheme. By establishing evaluation criteria with multiple set parameters as evaluation indicators, an evaluation system for optimizing support schemes is constructed to obtain the optimal support scheme.

[0005] As a further implementation, the chamber support scheme includes: The coordinate points for anchor bolt placement are calculated based on the stress distribution of the surrounding rock, and anchor bolts and lining support are added to the three-dimensional chamber excavation model. Based on the anchor bolt support and lining support parameters, the support structure and lining layer are simulated and analyzed using a discrete element model; a chamber support scheme is generated based on the analysis results.

[0006] As a further implementation, the coordinate points of the anchor bolt placement are represented as follows: ; in, θ For the arc angle, R Where is the radius of the chamber. l For the span of the chamber, h This refers to the height of the chamber.

[0007] As a further implementation method, the set parameters include: arch settlement, horizontal displacement, volume of collapsed blocks, number of collapsed blocks, and volume of the plastic zone.

[0008] As a further implementation, the construction of the support scheme optimization evaluation system to obtain the optimal support scheme includes: Range analysis was used to preliminarily analyze the results of the orthogonal experiment, and then matrix analysis was used to determine the optimal combination of factors and levels.

[0009] As a further implementation, the range analysis is as follows: ; in, R j For the worst, Y ij This represents the average value of the test results.

[0010] As a further implementation, the matrix includes an index matrix. M m Factor matrix T m Horizontal matrix S m , ω m Weight matrix and total weight matrix ω ; in, , ; p The number of indicators.

[0011] Secondly, embodiments of the present invention also provide a hydropower underground engineering support design system based on a discrete element model, comprising: The 3D chamber excavation model construction module is configured to: construct a 3D chamber excavation model based on the chamber type, chamber spatial parameter information, and key engineering geological parameters; The chamber support scheme generation module is configured to: dynamically simulate the chamber excavation support using a discrete element model based on the support parameters corresponding to the chamber excavation method, and generate a chamber support scheme. The optimal support scheme determination module is configured to: determine the evaluation criteria based on multiple set parameters as evaluation indicators, construct an evaluation system for support scheme optimization, and obtain the optimal support scheme.

[0012] Thirdly, embodiments of the present invention also provide an electronic device, including a memory and a processor, and computer instructions stored in the memory and running on the processor, wherein the computer instructions, when run by the processor, complete the steps in the aforementioned method for supporting underground hydropower engineering based on a discrete element model.

[0013] Fourthly, embodiments of the present invention also provide a computer-readable storage medium for storing computer instructions, which, when executed by a processor, complete the steps in the aforementioned method for designing support for underground hydropower engineering based on a discrete element model.

[0014] The beneficial effects of this invention are as follows: This invention constructs a three-dimensional excavation model of a tunnel by combining spatial parameters and key engineering geological parameters, which can accurately match the complex spatial morphology and geological background of hydropower tunnels. It also uses a discrete element method (DEM) model to simulate the dynamic process of tunnel excavation, providing real-time feedback on the constraint effect of support parameters on discrete rock masses. Furthermore, DEM simulation allows for the pre-simulation of multiple sets of support parameters during the design phase, enabling the selection of a foundation scheme that is "deformation-controllable and stress-safe," reducing rework caused by "unreasonable parameters" during construction. Finally, by constructing an evaluation system, the optimal scheme is selected, improving design efficiency and reducing construction costs. Attached Figure Description

[0015] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0016] Figure 1 This is a flowchart of the design method of the present invention according to one or more embodiments; Figure 2 This is a flowchart illustrating the specific steps of the design method according to one or more embodiments of the present invention; Figure 3 This is a design system block diagram of the present invention according to one or more embodiments. Detailed Implementation

[0017] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0018] Example 1: This embodiment provides a method for designing support systems for underground hydropower projects based on a discrete element model, such as... Figure 1 As shown, it includes the following steps: S1: Construct a three-dimensional excavation model of the chamber based on the chamber type, chamber spatial parameters, and key engineering geological parameters; S2: Based on the support parameters corresponding to the chamber excavation method, the discrete element model is used to dynamically simulate the chamber excavation support and generate the chamber support scheme. S3: Determine the evaluation criteria using multiple set parameters as evaluation indicators, construct an evaluation system for optimizing support schemes, and obtain the optimal support scheme.

[0019] Specifically, in step S1, such as Figure 2 As shown, the chamber type, excavation method, and spatial parameters are first determined. Key engineering geological parameters such as rock mechanical properties, hydrogeological parameters, and rock mass structural features are then assigned based on the actual geological conditions. Using the above data as input data, the number of excavation cycles is dynamically calculated, and the three-dimensional joint network topology of the tunnel face is reconstructed based on the two-dimensional crack identification results to generate a three-dimensional chamber excavation model.

[0020] The types of chambers include circular chambers, horseshoe-shaped chambers, and arched straight-walled chambers; the spatial parameters of the chambers include the chamber span, chamber height, and chamber length; and the excavation methods include the full-section method and the bench method.

[0021] In this embodiment, the three-dimensional chamber excavation model can be constructed using software such as FLAC3D and ANSYS / ABAQUS.

[0022] In step S1, the 3D modeling needs to maintain the stress balance. The initial stress is calculated based on the rock density and tunnel depth. The initial stress in the z-direction is calculated based on the weight of the rock layer, and the stress in the horizontal direction is calculated as λ times the vertical stress. Model top: Z-direction stress: σz1=γ H 1; Tunnel roof: Z-direction ground stress: σz2=γ H 2; Here, γ refers to the natural unit weight of the overburden soil layer above the tunnel, which is used to calculate the vertical stress generated by the self-weight of the soil above the tunnel arch. H 1 refers to the burial depth of the top of the model. H 2 refers to the depth of the tunnel roof. μ Poisson's ratio of the rock strata .

[0023] In step S2, for the three-dimensional chamber excavation model, the chamber excavation method is selected and the support parameters are input through field testing and engineering data; then, the dynamic simulation of chamber excavation and support is carried out based on discrete element analysis software to generate a chamber support scheme.

[0024] Furthermore, based on the three-dimensional chamber excavation model, support parameters are obtained in conjunction with engineering requirements. In this embodiment, algorithms such as neural networks can be used to establish a nonlinear mapping model based on engineering data. By inputting relevant parameters of the three-dimensional chamber excavation model (such as geological conditions, chamber dimensions, etc.) and engineering requirement parameters (such as safety factor, construction period, etc.), the neural network model can quickly predict suitable support parameters, such as support structure type, anchor length, diameter, and spacing, shotcrete thickness and strength grade, steel frame type and spacing, etc.

[0025] The coordinates of the anchor bolt placement are calculated based on the stress distribution of the surrounding rock, and anchor bolts and lining support are added to the three-dimensional chamber excavation model. Based on the anchor bolt support and lining support parameters, the support structure and lining layer are simulated and analyzed using a discrete element model; a chamber support scheme is generated based on the analysis results.

[0026] Furthermore, the coordinates of the anchor bolt placement points are represented as follows: ; in, θ For the arc angle, R Where is the radius of the chamber. l For the span of the chamber, h This refers to the height of the chamber.

[0027] In discrete element method (DEM) software, excavation can be simulated by progressively removing blocks from the model. After each excavation of a certain distance, the deformation and stress changes of the rock mass can be observed. During the excavation process, anchor bolt support and lining support should be applied in a timely manner.

[0028] The simulation analysis includes rock mass deformation analysis, stress analysis, and failure analysis. The displacement distribution of the rock mass in the model is observed, including the convergence deformation of the rock mass surrounding the chamber and surface subsidence. By analyzing the displacement contour maps, the main areas and magnitude of rock mass deformation are determined, and it is judged whether the rock mass is in a stable state.

[0029] In step S3, such as Figure 2 As shown, orthogonal experiments were conducted to establish a model evaluation standard with arch settlement, horizontal displacement, volume of collapsed blocks, number of collapsed blocks, and volume of plastic zone as evaluation indicators. An intelligent evaluation system for support schemes was constructed, and the optimal support scheme was determined based on the survey data.

[0030] Furthermore, range analysis was used to conduct a preliminary analysis of the obtained data, and then matrix analysis was used to determine the optimal combination of factors and levels. ; ; ; ; ; In the above formula, Yij This represents the average value of the corresponding experimental results. Rj For the worst, Y m is the Y value of the m-th factor. R m represents the range of the m-th factor, and ri represents the proportion of the range of the m-th factor in the sum of the first i ranges. M m is the index matrix of the m-th factor. T m is the factor matrix of the m-th factor, and Sm is the level matrix of the m-th factor. ω m is the weight matrix of the m-th factor. ω The total weight matrix, p The number of indicators.

[0031] Furthermore, the results of the orthogonal experiment were analyzed based on range analysis: the larger the range (R) of a factor, the more significant the influence of that factor on the experimental index; by comparing the R values ​​of each factor, the order of influence can be determined, and the optimal combination of support parameters can be obtained accordingly.

[0032] Based on the experimental analysis results, an index layer matrix M, a factor matrix T, and a level layer matrix S were constructed, and the weight matrix of each index was calculated. ω m and total weight matrix ω Based on this, the importance of factors and levels to the indicators is assessed; then, the optimal influencing factors are identified by the indicator weight matrix, and the optimal combination of levels is derived from the total weight matrix.

[0033] This embodiment constructs a three-dimensional excavation model of the tunnel by combining the spatial parameters of the tunnel and key engineering geological parameters. This model can accurately match the complex spatial morphology and geological background of the hydropower tunnel. The discrete element model is used to simulate the dynamic process of tunnel excavation, which can provide real-time feedback on the constraint effect of support parameters on discrete rock masses. At the same time, the discrete element simulation can be used to pre-run multiple sets of support parameters during the design stage, and select the basic scheme with "controllable deformation and safe stress" to reduce rework caused by "unreasonable parameters" during construction. By constructing an evaluation system, the optimal scheme is finally selected, which can improve design efficiency and reduce construction costs.

[0034] It should be noted that, in the actual construction phase, for the support design method of this embodiment, it is necessary to establish a dynamic monitoring mechanism for tunnel displacement and stress, collect on-site measured data such as surrounding rock deformation and support structure stress in real time, and iteratively revise the design scheme and intelligent optimization evaluation system by integrating monitoring data and theoretical models, thereby improving the engineering applicability of the design scheme and the evaluation system it constructs.

[0035] Example 2: This embodiment provides a support design system for underground hydropower engineering based on the discrete element model, including: The 3D chamber excavation model construction module is configured to: construct a 3D chamber excavation model based on the chamber type, chamber spatial parameter information, and key engineering geological parameters; The chamber support scheme generation module is configured to: dynamically simulate the chamber excavation support using a discrete element model based on the support parameters corresponding to the chamber excavation method, and generate a chamber support scheme. The optimal support scheme determination module is configured to: determine the evaluation criteria based on multiple set parameters as evaluation indicators, construct an evaluation system for support scheme optimization, and obtain the optimal support scheme.

[0036] Furthermore, such as Figure 3 As shown, the 3D tunnel excavation model construction module includes a tunnel type selection module, a tunnel segmentation module, an engineering parameter replication module, and a joint surface information component module. In this embodiment, the 3D tunnel excavation model construction module constructs a numerical model based on the tunnel type and tunnel segmentation parameters. It integrates actual engineering data to numerically assign values ​​to engineering geological parameters and couples the results of 2D fracture identification to establish a 3D joint network topology at the tunnel face, achieving high-precision 3D visualization modeling of underground tunnels.

[0037] The parameters for dividing the chamber include the starting station number, ending station number, starting station number of the first widened section, spacing limit of the widened section, length of the widened section, and spacing of the widened section.

[0038] The chamber support scheme generation module includes a chamber excavation method selection module and an excavation cycle step calculation module; the optimal support scheme determination module includes a chamber support parameter input module, a support scheme iterative operation module, a support scheme evaluation module, and a support scheme intelligent comparison module.

[0039] The chamber support scheme generation module in this embodiment automatically generates multiple support schemes based on the input support parameter information and the constructed three-dimensional chamber excavation model. It calls numerical analysis software through an integrated interface to perform multiple rounds of iterative calculations on the generated support schemes. At the same time, it uses a five-factor, five-level orthogonal experimental method to construct a comprehensive evaluation system for the support schemes. Finally, through multi-dimensional comparative analysis, the support scheme with the best safety and economy is selected.

[0040] Example 3: This embodiment provides an electronic device, including a memory and a processor, as well as computer instructions stored in the memory and running on the processor. When the processor executes the computer instructions, it completes the steps in the hydropower underground engineering support design method based on the discrete element model described in Embodiment 1.

[0041] Example 4: This embodiment provides a computer-readable storage medium for storing computer instructions. When the computer instructions are executed by a processor, they complete the steps in the hydropower underground engineering support design method based on a discrete element model as described in Embodiment 1.

[0042] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for designing support systems for underground hydropower projects based on a discrete element model, characterized in that, include: Based on the chamber type and spatial parameters, a three-dimensional chamber excavation model is constructed in conjunction with key engineering geological parameters. Based on the support parameters corresponding to the chamber excavation method, the discrete element model is used to dynamically simulate the chamber excavation support and generate a chamber support scheme. By establishing evaluation criteria with multiple set parameters as evaluation indicators, an evaluation system for optimizing support schemes is constructed to obtain the optimal support scheme.

2. The method for designing support for underground hydropower engineering based on a discrete element model according to claim 1, characterized in that, The chamber support scheme includes: The coordinate points for anchor bolt placement are calculated based on the stress distribution of the surrounding rock, and anchor bolts and lining support are added to the three-dimensional chamber excavation model. Based on the anchor bolt support and lining support parameters, the support structure and lining layer are simulated and analyzed using a discrete element model; a chamber support scheme is generated based on the analysis results.

3. The method for designing support for underground hydropower engineering based on a discrete element model according to claim 2, characterized in that, The coordinate points for the anchor bolt placement are represented as follows: ； in, θ For the arc angle, R Where is the radius of the chamber. l For the span of the chamber, h This refers to the height of the chamber.

4. The method for designing support for underground hydropower engineering based on a discrete element model according to claim 1, characterized in that, The set parameters include: crown settlement, horizontal displacement, volume of collapsed blocks, number of collapsed blocks, and volume of the plastic zone.

5. The method for designing support for underground hydropower engineering based on a discrete element model according to claim 1, characterized in that, The optimization evaluation system for constructing support schemes yields the following optimal support schemes: Range analysis was used to preliminarily analyze the results of the orthogonal experiment, and then matrix analysis was used to determine the optimal combination of factors and levels.

6. The method for designing support for underground hydropower engineering based on a discrete element model according to claim 5, characterized in that, The range analysis is as follows: ； in, R j Extremely poor Y ij This represents the average value of the test results.

7. The method for designing support for underground hydropower engineering based on a discrete element model according to claim 5, characterized in that, The matrix includes an index matrix. M m Factor matrix T m Horizontal matrix S m , ω m Weight matrix and total weight matrix ω ; in, , ; p The number of indicators.

8. A support design system for underground hydropower engineering based on discrete element model, characterized in that, include: The 3D chamber excavation model construction module is configured to: construct a 3D chamber excavation model based on the chamber type, chamber spatial parameter information, and key engineering geological parameters; The chamber support scheme generation module is configured to: dynamically simulate the chamber excavation support using a discrete element model based on the support parameters corresponding to the chamber excavation method, and generate a chamber support scheme. The optimal support scheme determination module is configured to: determine the evaluation criteria based on multiple set parameters as evaluation indicators, construct an evaluation system for support scheme optimization, and obtain the optimal support scheme.

9. An electronic device, characterized in that, It includes a memory and a processor, as well as computer instructions stored in the memory and running on the processor. When the processor executes the computer instructions, it completes the steps in the hydropower underground engineering support design method based on the discrete element model as described in any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, Used to store computer instructions, which, when executed by a processor, complete the steps in the hydropower underground engineering support design method based on a discrete element model as described in any one of claims 1-7.

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