A method for supporting scheme decision and optimization of deep super-large span cavern based on critical section

Abstract

The application provides a deep large-span cavern support scheme decision and optimization method based on a critical section, wherein through rock mass mechanical tests and numerical analysis means in actual engineering, a critical span of the deep large-span cavern is quantitatively obtained; the design target span of the current deep large-span cavern is compared with the critical span to obtain a deep large-span cavern overall stability determination result; and based on the deep large-span cavern overall stability result, the deep large-span cavern support scheme is decided and optimized according to different preset rules. Compared with the prior art, the application reduces the subjective experience dependence, ensures that the design result can meet the specification safety requirements in any case, the risk is controllable, and the cost is optimal. The application organically integrates the overall stability analysis and the local stability analysis, the permanent support and the temporary support, and the active support and the passive support in a complete process, and ensures the system and integrity of the design scheme.

Description

Technical Field

[0001] This invention relates to the field of cavern support scheme decision-making and classification technology, and in particular to a method for decision-making and optimization of support schemes for deep, ultra-large span caverns based on critical cross sections. Background Technology

[0002] In existing technologies, the design of deep underground caverns often prioritizes safety as the sole or primary objective, lacking an automated optimization mechanism that embeds economic indicators into the design process. This frequently leads to "overly safe" support schemes, resulting in waste, or requiring numerous repeated calculations to find a better solution. It relies heavily on engineers' experience and analogies or universally applicable clauses recommended by specifications, lacking unified decision-making standards and exhibiting strong reliance on experience. For ultra-large span caverns under specific geological conditions, the lack of a quantitative, scientific, and unified standard to guide the initial selection of support methods easily leads to conservative or insufficient designs. Furthermore, existing processes typically separate overall stability analysis from local stability analysis, resulting in a linear design process lacking systematicity and feedback. For the coordinated application of different levels of support, such as system anchors and prestressed anchor cables, there is a lack of clear activation conditions and switching logic. Therefore, there is an urgent need for a decision-making and classification method for support schemes in deep ultra-large span caverns based on critical sections to address the problems in existing technologies. Summary of the Invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art, and proposes a decision-making and optimization method for support schemes of deep ultra-large span tunnels based on critical cross sections.

[0004] In a first aspect, embodiments of the present invention provide a method for decision-making and optimization of support schemes for deep, ultra-large span tunnels based on critical cross-sections, including:

[0005] Based on the results of rock mechanics tests and numerical analysis in actual engineering, the critical span of deep ultra-large span tunnels is obtained.

[0006] By comparing the current design target span with the critical span of the deep ultra-large span cavern, the overall stability judgment result of the deep ultra-large span cavern is obtained.

[0007] Based on the overall stability results of the deep ultra-large span cavern, the support schemes for the deep ultra-large span cavern are decided and optimized according to different preset rules.

[0008] Furthermore, based on the results of rock mechanics tests and numerical analysis in actual engineering projects, the critical span of deep ultra-large span tunnels was obtained. The specific steps included:

[0009] Determine the rock mass strain softening parameters based on rock mechanics tests in actual engineering projects;

[0010] The constitutive model of the rock mass is further developed based on the aforementioned rock mass strain softening parameters;

[0011] Based on the constitutive model of the rock mass after secondary development, a nonlinear finite element initial model is constructed to solve the critical stability section of the underground cavern.

[0012] The nonlinear finite element initial model is solved to obtain the overall tangential stiffness of the model at each calculation step;

[0013] Based on the overall tangent stiffness, the minimum eigenvalue of the overall tangent stiffness matrix is ​​calculated;

[0014] Based on the minimum eigenvalue, the instability state of deep ultra-large span caverns is determined, and based on the determination of the instability state, the critical stability section and span of the deep ultra-large span caverns are obtained.

[0015] Furthermore, based on the constitutive model of the rock mass after secondary development, a nonlinear finite element initial model for solving the critical stability section of the underground cavern is constructed; the nonlinear finite element model is solved to obtain the overall tangential stiffness under the calculation time step, and the specific steps include:

[0016] Based on the actual excavation conditions of the underground cavern, a finite element model of the underground engineering was constructed, including the cavern geometry, excavation steps, and initial geostress field. The model was meshed using transition mesh technology, and corresponding parameters and boundary conditions were set.

[0017] The global tangent stiffness matrix is ​​obtained directly by a nonlinear finite element solver. When the nonlinear finite element solver cannot directly obtain the global tangent stiffness matrix, the global tangent stiffness matrix under the current state is automatically extracted by a developed script. The plastic area or feature point displacement of the model is monitored in real time. When the plastic area or displacement is greater than a preset threshold, the tangent stiffness matrix for each subsequent calculation step is extracted.

[0018] Calculate the minimum eigenvalue of the tangent stiffness matrix. Determine whether the system is unstable by using the minimum eigenvalue (theoretically λmin≤0, or close to 0). Continuously change the model shape and span proportionally until the maximum span section in the stable state is found, which is the critical stable section and critical span.

[0019] Furthermore, the design target span of the current deep ultra-large span cavern is compared with the critical span to obtain the overall stability judgment result of the deep ultra-large span cavern. The specific steps include: comparing the design target span of the current deep ultra-large span cavern with the critical span; if the design target span of the current deep ultra-large span cavern is not greater than the critical span, the overall stability result of the deep ultra-large span cavern is that the stability is good, and subsequent design only needs to consider the local stability of the cavern; if the design target span of the current deep ultra-large span cavern is greater than the critical span, the overall stability result of the deep ultra-large span cavern is that there is a risk of overall instability, and subsequent design needs to consider the overall stability of the cavern.

[0020] Furthermore, when the overall stability result of the deep ultra-large span cavern is good, local stability control is implemented. The steps for decision-making and optimization of the support scheme for the deep ultra-large span cavern include:

[0021] The local damage of deep, ultra-large span caverns is analyzed and the anchor bolt parameters are designed. The block theory or discrete element method is used to identify and calculate the stability of key blocks on the cavern surface that may be unstable. Based on the calculation results, the anchor bolt parameters of the cavern are designed.

[0022] The total anti-sliding force provided by the anchor bolts is calculated using the anchor bolt parameters of the cavern. The cavern safety factor is then calculated based on the ratio of the total anti-sliding force provided by the anchor bolts to the total sliding force of the key blocks. This safety factor is compared with the minimum design safety factor of the cavern. When the safety factor of the cavern is greater than the minimum design safety factor, it is taken as the total safety factor of the cavern. The cavern support scheme is then decided and optimized based on this safety factor.

[0023] Furthermore, when the overall stability result of the deep ultra-large span cavern indicates a risk of overall instability, overall stability control is implemented. The steps for decision-making and optimization of the support scheme for the deep ultra-large span cavern include:

[0024] Preliminary calculations were performed on the surrounding rock pressure of the tunnel to simulate the overall stress-strain state after the tunnel excavation and to quantify the total surrounding rock pressure acting on the initial support.

[0025] An objective function is established based on the safety parameters and economic considerations of the cavern. The objective function is then solved to obtain the optimal anchor bolt scheme for the cavern.

[0026] Furthermore, an objective function is established based on the cavern's safety parameters and economic considerations. The objective function is then solved to obtain the optimal anchor bolt scheme for the cavern. Specific steps include:

[0027] Parametric modeling is performed to generate multiple design parameter combinations for cavern anchors within the scope of the actual engineering project. The parameter combinations include at least anchor length, spacing, and diameter.

[0028] The constraints are defined as follows: the actual safety factor F_S ≥ the design minimum safety factor F_S_min;

[0029] The actual safety factor F_S is calculated using the following formula:

[0030] F_S = R_total / P_total;

[0031] Where R_total is the total bearing capacity of all anchor bolts, which is obtained by calculation according to the method in the specification, and P_total is the total surrounding rock pressure calculated.

[0032] For parameter combination optimization and decision-making, all parameter combinations are traversed, all schemes that meet the safety constraints are screened out, and the scheme with the lowest total cost is selected as the optimal cavern anchor scheme.

[0033] Furthermore, to obtain the optimal anchor bolt scheme for the cavern, the specific steps also include:

[0034] Determine if an optimal anchor bolt scheme for the cavern exists. If it does, adopt the scheme, and its safety factor F_S is the total safety factor; the design is then complete. If it does not exist, the process enters the active support design phase, which includes the following steps:

[0035] Prestressed anchor cables are used as the main support method. Based on the surrounding rock pressure, the tonnage, length and spacing of the prestressed anchor cables are designed, and they are supplemented with optimized cavern anchors and steel arches to form a composite support system.

[0036] The composite support system is verified by numerical simulation, and its overall safety factor F_S is calculated using numerical simulation. If the safety factor F_S is not less than the design minimum safety factor F_S_min, then the optimal anchor bolt scheme for the cavern is designed.

[0037] Secondly, the present invention also discloses an electronic device, comprising:

[0038] One or more processors;

[0039] Memory, used to store one or more programs;

[0040] When the one or more programs are executed by the one or more processors, the one or more processors implement the support scheme decision and optimization method.

[0041] Thirdly, the present invention also discloses a computer-readable medium storing a computer program, characterized in that the computer program, when executed by a processor, implements the steps in the support scheme decision and optimization method.

[0042] The present invention provides a method for decision-making and optimization of support schemes for deep ultra-large span caverns based on critical cross-sections. This method obtains the critical span of the deep ultra-large span cavern through rock mechanics tests and numerical analysis in actual engineering projects. It then compares the current design target span of the deep ultra-large span cavern with the critical span to obtain the overall stability result of the cavern. Based on the overall stability result of the deep ultra-large span cavern, the support schemes for the deep ultra-large span cavern are decided and optimized according to different preset rules.

[0043] This invention, through the analysis of the overall tangential stiffness of elements in nonlinear finite element analysis, determines the critical stability section as a clear quantitative criterion, transforming the originally ambiguous selection of support methods into a clear logical decision-making process. This reduces reliance on subjective experience, making the decision-making process more scientific and transparent. This invention possesses inherent conservatism and redundancy. When the system anchor bolts cannot meet the requirements, a higher-level active support scheme is automatically activated, ensuring that the design results meet safety specifications under any circumstances, and risks are controllable. This invention streamlines and automates the analysis, optimization, and decision-making process. Engineers only need to input parameters to quickly obtain the optimal or safest solution according to the process, avoiding a large amount of repetitive calculations and manual data exchange between different software. This invention organically integrates overall stability analysis with local stability analysis, permanent support with temporary support, and active support with passive support into a complete process, ensuring the systematicity and integrity of the design scheme. Attached Figure Description

[0044] Figure 1 A flowchart illustrating a method for decision-making and optimization of support schemes for deep ultra-large span tunnels based on critical cross sections, provided in an embodiment of the present invention;

[0045] Figure 2 A flowchart illustrating the method for obtaining the critical span of a deep, ultra-large span cavern, provided in an embodiment of the present invention;

[0046] Figure 3 This is a structural block diagram of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0047] To enable those skilled in the art to better understand the technical solutions of the present invention, exemplary embodiments of the present invention are described below in conjunction with the accompanying drawings, including various details of the embodiments of the present invention to aid understanding. These should be considered merely exemplary. Therefore, those skilled in the art should recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of the present invention. Similarly, for clarity and brevity, descriptions of well-known functions and structures are omitted in the following description.

[0048] Where there is no conflict, the various embodiments of the present invention and the features thereof may be combined with each other.

[0049] As used herein, the term “and / or” includes any and all combinations of one or more related enumerated entries.

[0050] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used herein, the singular forms “a” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will also be understood that when the terms “comprising” and / or “made of” are used in this specification, the presence of the stated feature, integral, step, operation, element, and / or component is specified, but the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or groups thereof is not excluded. Terms such as “connected” or “linked” are not limited to physical or mechanical connections but can include electrical connections, whether direct or indirect.

[0051] Unless otherwise specified, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art. It will also be understood that terms such as those defined in commonly used dictionaries should be interpreted as having the meaning consistent with their meaning in the context of the relevant art and the invention, and will not be interpreted as having an idealized or overly formal meaning unless expressly so defined herein.

[0052] In the technical solution of this invention, the collection, storage, use, processing, transmission, provision, and disclosure of user personal information all comply with relevant laws and regulations and do not violate public order and good morals. The use of user data in this technical solution follows relevant national laws and regulations (e.g., the "Information Security Technology - Personal Information Security Specification"). For example: appropriate measures are taken for personal information access control; restrictions are imposed on the display of personal information; the purpose of using personal information does not exceed the scope of direct or reasonable association; and explicit identity targeting is eliminated when using personal information to avoid precisely locating a specific individual.

[0053] To address at least one of the technical problems existing in the aforementioned related technologies, this embodiment provides a method for decision-making and optimization of support schemes for deep ultra-large span tunnels based on critical cross sections.

[0054] This embodiment discloses a method for decision-making and optimization of support schemes for deep, ultra-large span tunnels based on critical sections, such as... Figure 1 ,include:

[0055] S100. Based on the results of rock mechanics tests and numerical analysis in actual engineering projects, the critical span of deep ultra-large span caverns is obtained; specifically, in this embodiment, based on the results of rock mechanics tests and numerical analysis in actual engineering projects, the critical span of deep ultra-large span caverns is obtained, such as... Figure 2The specific steps include:

[0056] S101. Determine the rock mass strain softening parameters based on rock mechanics tests in actual engineering projects; wherein, the specific method for determining the rock mass strain softening parameters based on rock mechanics tests in actual engineering projects includes: obtaining the stress-plastic strain curve in the actual engineering project based on rock mechanics tests, and performing linear, exponential, or piecewise softening fitting on the stress-plastic strain curve to obtain the rock mass strain softening parameter function.

[0057] S102. The rock mass constitutive model is further developed based on the rock mass strain softening parameters; wherein, the secondary development of the rock mass constitutive model based on the rock mass strain softening parameters includes: using the rock mass constitutive model built into the user material subroutine module in the finite element solver, the constitutive model is further developed, and the rock mass strain softening parameters are imported into the constitutive model to obtain a rock mass constitutive model that conforms to the actual engineering situation.

[0058] S103. Based on the constitutive model of the rock mass after secondary development, a nonlinear finite element initial model for solving the critical stability section of the underground cavern is constructed; specifically, the nonlinear finite element initial calculation model for the critical stability section of the underground cavern is constructed based on the constitutive model of the rock mass after secondary development, including the following methods:

[0059] Based on the actual excavation conditions of the underground cavern, a finite element model of the underground engineering was constructed, including the cavern geometry, excavation steps, and initial geostress field. The model was meshed using transition mesh technology, and corresponding parameters and boundary conditions were set.

[0060] S104. Solve the nonlinear finite element initial model to obtain the overall tangent stiffness of the model at each calculation step; wherein, the method for solving the nonlinear finite element model to obtain the overall tangent stiffness of the model at each calculation step includes: directly obtaining the overall tangent stiffness matrix through the nonlinear finite element solver; when the nonlinear finite element solver cannot directly obtain the overall tangent stiffness matrix, automatically extracting the overall tangent stiffness matrix under the current state through a developed script; monitoring the plastic zone area or feature point displacement of the model in real time; and when the plastic zone area or displacement is greater than a preset threshold, extracting the tangent stiffness matrix for each subsequent calculation step.

[0061] S105. Based on the overall tangent stiffness, calculate the minimum eigenvalue of the overall tangent stiffness matrix; the specific method for calculating the minimum eigenvalue of the overall tangent stiffness matrix based on the overall tangent stiffness includes: calling the eigenvalue calculation solver to solve for the eigenvalue of the overall tangent stiffness matrix at each iteration step, and sorting all the eigenvalues ​​from smallest to largest to obtain the minimum eigenvalue.

[0062] S106. Based on the minimum eigenvalue, the instability state of deep ultra-large span caverns is determined. Based on the determination of the instability state, the critical stability section and span of the deep ultra-large span cavern are obtained. The specific method for determining the critical stability section of underground caverns based on the minimum eigenvalue includes:

[0063] The minimum eigenvalue is compared with the value 0. When the minimum eigenvalue is greater than or equal to 0, the cavern at that time step is in a stable state. The minimum eigenvalue at the next time step is calculated. If the minimum eigenvalue after traversing the overall tangent stiffness matrix of all calculation time steps is greater than or equal to 0, it indicates that the initial cavern shape is in a self-stable state. At this time, it is necessary to adjust the initial nonlinear finite element calculation model of the critical stability section of the underground cavern (the model shape and span can be changed proportionally, or the step size of the span can be set), and repeat the above steps until the minimum eigenvalue is less than 0. When the minimum eigenvalue is less than 0, the cavern at that time step is unstable, and the corresponding cavern cross-sectional state is marked as the critical cross-sectional state, and the corresponding span is the critical stability span.

[0064] S200. Compare the current design target span of the deep ultra-large span cavern with the critical span to obtain the overall stability result of the deep ultra-large span cavern; in this embodiment, the specific steps for comparing the current design target span of the deep ultra-large span cavern with the critical span to obtain the overall stability result of the deep ultra-large span cavern include:

[0065] By comparing the current design target span of the deep ultra-large span cavern with the critical span, if the current design target span of the deep ultra-large span cavern is not greater than the critical span, the overall stability result of the deep ultra-large span cavern is that the stability is good, and subsequent design only needs to consider the local stability of the cavern; if the current design target span of the deep ultra-large span cavern is greater than the critical span, the overall stability result of the deep ultra-large span cavern is that there is a risk of overall instability, and subsequent design needs to consider the overall stability of the cavern.

[0066] For example, suppose the critical span of a deep, ultra-large span cavern is 30 meters, calculated based on rock mechanics parameters. Now, consider two different design target span scenarios: When the design target span is 25 meters, the design target span (25 meters) is not greater than the critical span (30 meters), i.e., 25 ≤ 30. According to the rule, since the design target span is not greater than the critical span, the overall stability of the cavern is judged to be relatively good, and it enters the local stability design stage. When the design target span is 40 meters, the design target span (40 meters) is greater than the critical span (30 meters), i.e., 40 > 30. According to the rule, since the design target span is greater than the critical span, the overall stability of the cavern is judged to have a risk of overall instability, and it enters the overall stability design stage.

[0067] S300. Based on the overall stability results of the deep ultra-large span cavern, the support scheme of the deep ultra-large span cavern is decided and optimized according to different preset rules.

[0068] Specifically, when the overall stability result of the deep ultra-large span cavern is good, the steps for decision-making and optimization of the support scheme for the deep ultra-large span cavern include:

[0069] S301a. Analysis of localized failure in deep, ultra-large span tunnels and design of anchor bolt parameters are conducted. Block theory or discrete element method is used to identify and calculate the stability of key blocks on the tunnel surface that may become unstable. Based on the calculation results, the anchor bolt parameters for the tunnel are designed. Specifically, the load mainly consists of pressure from locally loosened blocks. Block theory (such as the Keyblock method) or discrete element method (such as UDEC / 3DEC) is used to identify and calculate the stability of key blocks on the tunnel surface that may become unstable. Based on the analysis results, the parameters of the system anchor bolts (length L, spacing S, diameter D, etc.) are designed to provide sufficient support force to prevent the key blocks from slipping.

[0070] S302a. The total anti-slip force provided by the anchor bolts is calculated using the anchor bolt parameters of the cavern. The cavern safety factor is calculated based on the ratio of the total anti-slip force provided by the anchor bolts to the total sliding force of the critical block. This safety factor is compared with the minimum design safety factor of the cavern. When the cavern safety factor is greater than the minimum design safety factor, it is taken as the total safety factor of the cavern. The cavern support scheme is then decided and optimized based on this safety factor. Specifically, in this method, the system anchor bolts are the final support scheme. Its safety factor (F_S) is obtained by calculating the ratio of the total anti-slip force provided by the anchor bolts to the total sliding force of the critical block. If F_S ≥ the design requirement value F_S_min (the minimum design safety factor is determined based on the cavern surrounding rock grade and safety level, and can be obtained according to industry standards), then the design is complete, and this safety factor is the total safety factor of the cavern.

[0071] In some preferred embodiments, when the overall stability result of a deep, ultra-large span cavern indicates a risk of overall instability, the steps for decision-making and optimization of the support scheme for the deep, ultra-large span cavern include:

[0072] S301b. Perform preliminary calculations on the surrounding rock pressure of the tunnel, simulate the overall stress-strain state after the tunnel excavation, and quantify the total surrounding rock pressure acting on the initial support.

[0073] S302b. Establish an objective function based on the cavern safety parameters and economic considerations, solve the objective function, and obtain the optimal anchor bolt scheme for the cavern. Specifically, establishing the objective function based on the cavern safety parameters and economic considerations, and solving the objective function to obtain the optimal anchor bolt scheme for the cavern includes the following steps:

[0074] Parametric modeling is performed to generate multiple design parameter combinations for cavern anchors within the scope of the actual engineering project. The parameter combinations include at least anchor length, spacing, and diameter.

[0075] The constraints are defined as follows: the actual safety factor F_S ≥ the design minimum safety factor F_S_min;

[0076] The actual safety factor F_S is calculated using the following formula:

[0077] F_S = R_total / P_total;

[0078] Where R_total is the total bearing capacity of all anchor bolts, which is obtained by calculation according to the method in the specification, and P_total is the total surrounding rock pressure calculated.

[0079] For parameter combination optimization and decision-making, all parameter combinations are traversed, all schemes that meet the safety constraints are screened out, and the scheme with the lowest total cost is selected as the optimal cavern anchor scheme.

[0080] In some preferred embodiments, obtaining the optimal anchor bolt scheme for the cavern includes the following steps:

[0081] S303b. Determine if an optimal cavern anchor bolt scheme exists. If it does, adopt the scheme, and its safety factor F_S is the total safety factor; the design is complete. If it does not exist, meaning that none of the system anchor bolt schemes can satisfy F_S_min, the process enters the active support design phase, the specific steps of which include:

[0082] S304b. Prestressed anchor cables are used as the main support method. Based on the surrounding rock pressure, the tonnage, length and spacing of the prestressed anchor cables are designed, and they are supplemented with optimized cavern anchors and steel arches to form a composite support system.

[0083] S305b. Perform numerical simulation verification on the composite support system and calculate its overall safety factor F_S using numerical simulation; if the safety factor F_S is not less than the design minimum safety factor F_S_min, then the optimal anchor bolt scheme design for the cavern is completed.

[0084] The method for decision-making and optimization of support schemes for deep ultra-large span caverns based on critical cross-sections provided in this embodiment quantitatively obtains the critical span of deep ultra-large span caverns by means of rock mechanics tests and numerical analysis in actual engineering; compares the current design target span of the deep ultra-large span cavern with the critical span to obtain the overall stability judgment result of the deep ultra-large span cavern; based on the overall stability result of the deep ultra-large span cavern, the support schemes for the deep ultra-large span caverns are decided and optimized according to different preset rules.

[0085] This embodiment uses the analysis of the overall tangential stiffness of the elements in nonlinear finite element analysis to determine the critical stability section—a clear quantitative criterion. This transforms the originally ambiguous selection of support methods into a clear logical decision-making process, reducing reliance on subjective experience and making the decision-making process more scientific and transparent. This invention possesses inherent conservatism and redundancy. When the system anchor bolts cannot meet the requirements, a higher-level active support scheme will be automatically activated, ensuring that the design results meet safety specifications under any circumstances and that risks are controllable. This invention streamlines and automates the analysis, optimization, and decision-making process. Engineers only need to input parameters to quickly obtain the optimal or safest solution according to the process, avoiding a large number of repeated calculations and manual data exchange between different software. This invention organically integrates overall stability analysis with local stability analysis, permanent support with temporary support, and active support with passive support into a complete process, ensuring the systematicity and integrity of the design scheme.

[0086] Based on the same inventive concept, embodiments of the present invention also provide an electronic device. Figure 3 This is a structural block diagram of an electronic device provided in an embodiment of the present invention. Figure 3 As shown, an embodiment of the present invention provides an electronic device including: one or more processors 101, a memory 102, and one or more I / O interfaces 103. The memory 102 stores one or more programs, which, when executed by the one or more processors, enable the one or more processors to implement any of the support scheme decision and optimization methods described in the above embodiments; the one or more I / O interfaces 103 are connected between the processor and the memory, configured to enable information interaction between the processor and the memory.

[0087] The processor 101 is a device with data processing capabilities, including but not limited to a central processing unit (CPU); the memory 102 is a device with data storage capabilities, including but not limited to random access memory (RAM, more specifically SDRAM, DDR, etc.), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), and flash memory (FLASH); the I / O interface (read / write interface) 103 is connected between the processor 101 and the memory 102, and can realize information interaction between the processor 101 and the memory 102, including but not limited to a data bus (Bus).

[0088] In some embodiments, the processor 101, memory 102, and I / O interface 103 are interconnected via bus 104, and thus connected to other components of the computing device.

[0089] In some embodiments, the one or more processors 101 include a field-programmable gate array.

[0090] This invention also provides a computer-readable medium. The computer-readable medium stores a computer program, which, when executed by a processor, implements the steps of any of the support scheme decision and optimization methods described in the above embodiments. The computer-readable storage medium may be volatile or non-volatile.

[0091] This invention also provides a computer program product, including computer-readable code, or a non-volatile computer-readable storage medium carrying computer-readable code. When the computer-readable code is run in the processor of an electronic device, the processor in the electronic device executes the above-described support scheme decision and optimization method.

[0092] Those skilled in the art will understand that all or some of the steps, systems, and apparatuses disclosed above, and their functional modules / units, can be implemented as software, firmware, hardware, or suitable combinations thereof. In hardware implementations, the division between functional modules / units mentioned above does not necessarily correspond to the division of physical components; for example, a physical component may have multiple functions, or a function or step may be performed collaboratively by several physical components. Some or all physical components may be implemented as software executed by a processor, such as a central processing unit, digital signal processor, or microprocessor, or as hardware, or as an integrated circuit, such as an application-specific integrated circuit (ASIC). Such software can be distributed on a computer-readable storage medium, which may include computer storage media (or non-transitory media) and communication media (or transient media).

[0093] As is known to those skilled in the art, the term computer storage medium includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information, such as computer-readable program instructions, data structures, program modules, or other data. Computer storage media includes, but is not limited to, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM), static random access memory (SRAM), flash memory or other memory technologies, portable compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical disc storage, magnetic cartridges, magnetic tape, disk storage or other magnetic storage devices, or any other medium that can be used to store desired information and is accessible to a computer. Furthermore, it is known to those skilled in the art that communication media typically contain computer-readable program instructions, data structures, program modules, or other data in modulated data signals such as carrier waves or other transmission mechanisms, and may include any information delivery medium.

[0094] The computer-readable program instructions described herein can be downloaded from computer-readable storage media to various computing / processing devices, or downloaded via a network, such as the Internet, local area network, wide area network, and / or wireless network, to an external computer or external storage device. The network may include copper transmission cables, fiber optic transmission, wireless transmission, routers, firewalls, switches, gateway computers, and / or edge servers. A network adapter card or network interface in each computing / processing device receives the computer-readable program instructions from the network and forwards them to the computer-readable storage media in the respective computing / processing device.

[0095] The computer program instructions used to perform the operations of this invention may be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, state setting data, or source code or object code written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Smalltalk, C++, etc., and conventional procedural programming languages ​​such as the "C" language or similar programming languages. The computer-readable program instructions may be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving a remote computer, the remote computer may be connected to the user's computer via any type of network—including a local area network (LAN) or a wide area network (WAN)—or may be connected to an external computer (e.g., via the Internet using an Internet service provider). In some embodiments, electronic circuitry, such as programmable logic circuitry, field-programmable gate arrays (FPGAs), or programmable logic arrays (PLAs), is personalized by utilizing state information from the computer-readable program instructions. This electronic circuitry can execute the computer-readable program instructions to implement various aspects of the invention.

[0096] The computer program product described herein can be implemented specifically through hardware, software, or a combination thereof. In one alternative embodiment, the computer program product is specifically embodied in a computer storage medium; in another alternative embodiment, the computer program product is specifically embodied in a software product, such as a software development kit (SDK), etc.

[0097] Various aspects of the present invention are described herein with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It should be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer-readable program instructions.

[0098] These computer-readable program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus to produce a machine such that, when executed by the processor of the computer or other programmable data processing apparatus, they create means for implementing the functions / actions specified in one or more blocks of the flowchart and / or block diagram. These computer-readable program instructions can also be stored in a computer-readable storage medium that causes a computer, programmable data processing apparatus, and / or other device to operate in a particular manner; thus, the computer-readable medium storing the instructions comprises an article of manufacture that includes instructions for implementing aspects of the functions / actions specified in one or more blocks of the flowchart and / or block diagram.

[0099] Computer-readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device to cause a series of operational steps to be performed on the computer, other programmable data processing apparatus, or other device to produce a computer-implemented process, thereby causing the instructions executed on the computer, other programmable data processing apparatus, or other device to perform the functions / actions specified in one or more boxes of a flowchart and / or block diagram.

[0100] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of an instruction, which contains one or more executable instructions for implementing a specified logical function. In some alternative implementations, the functions marked in the blocks may occur in a different order than those shown in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, may be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions.

[0101] Example embodiments have been disclosed herein, and while specific terminology has been used, it is for illustrative purposes only and should be construed as such, and is not intended to be limiting. In some instances, it will be apparent to those skilled in the art that features, characteristics, and / or elements described in conjunction with particular embodiments may be used alone, or in combination with features, characteristics, and / or elements described in conjunction with other embodiments, unless otherwise expressly indicated. Therefore, those skilled in the art will understand that various changes in form and detail may be made without departing from the scope of the invention as set forth in the appended claims.

Claims

1. A method for decision-making and optimization of support schemes for deep, ultra-large span tunnels based on critical cross-sections, characterized in that, include: Based on the results of rock mechanics tests and numerical analysis in actual engineering, the critical span of deep ultra-large span tunnels is obtained. The specific steps include: Determine the rock mass strain softening parameters based on rock mechanics tests in actual engineering projects; The constitutive model of the rock mass is further developed based on the aforementioned rock mass strain softening parameters; Based on the constitutive model of the rock mass after secondary development, a nonlinear finite element initial model is constructed to solve the critical stability section of the underground cavern. The nonlinear finite element initial model is solved to obtain the overall tangential stiffness of the model at each calculation step; Based on the secondary-developed rock mass constitutive model, a nonlinear finite element initial model for solving the critical stability section of underground caverns is constructed; the nonlinear finite element model is solved to obtain the overall tangential stiffness under the calculation time step. Specific steps include: Based on the actual excavation conditions of the underground cavern, a finite element model of the underground engineering was constructed, including the cavern geometry, excavation steps, and initial geostress field. The model was meshed using transition mesh technology, and corresponding parameters and boundary conditions were set. The global tangent stiffness matrix is ​​obtained directly through a nonlinear finite element solver. When the nonlinear finite element solver cannot directly obtain the global tangent stiffness matrix, the global tangent stiffness matrix under the current state is automatically extracted through a developed script. The plastic zone area or feature point displacement of the model is monitored in real time. When the plastic zone area or displacement is greater than a preset threshold, the tangent stiffness matrix for each subsequent calculation step is extracted. Calculate the minimum eigenvalue of the tangent stiffness matrix, determine whether the system is unstable by the minimum eigenvalue, and continuously change the model shape and span proportionally until the maximum span section in the stable state is found, which is the critical stable section and critical span. Based on the overall tangent stiffness, the minimum eigenvalue of the overall tangent stiffness matrix is ​​calculated; Based on the minimum eigenvalue, the instability state of the deep ultra-large span cavern is determined, and based on the determination of the instability state, the critical stability section and span of the deep ultra-large span cavern are obtained. The overall stability of a deep, ultra-large span cavern is determined by comparing its design target span with its critical span. The specific steps include: comparing the design target span with the critical span; if the current design target span is not greater than the critical span, the overall stability of the deep, ultra-large span cavern is considered good, and subsequent design only needs to consider the local stability of the cavern; if the current design target span is greater than the critical span, the overall stability of the deep, ultra-large span cavern is considered to have a risk of overall instability, and subsequent design needs to consider the overall stability of the cavern. Based on the overall stability results of the deep ultra-large span cavern, the support schemes for the deep ultra-large span cavern are decided and optimized according to different preset rules; when the overall stability result of the deep ultra-large span cavern indicates a risk of overall instability, overall stability control is implemented. The steps for deciding and optimizing the support schemes for the deep ultra-large span cavern include: The pressure of the surrounding rock in the cavern is calculated to simulate the overall stress-strain state after the cavern is excavated, and the total pressure of the surrounding rock acting on the initial support is quantitatively calculated. Based on the safety parameters and economic considerations of the cavern, an objective function is established; the objective function is solved to obtain the optimal anchor bolt scheme for the cavern; the specific steps include: Parametric modeling is performed to generate multiple design parameter combinations for cavern anchors within the scope of the actual engineering project. The parameter combinations include at least the anchor length, spacing, and diameter. The constraints are defined as follows: the actual safety factor F_S ≥ the design minimum safety factor F_S_min; The actual safety factor F_S is calculated using the following formula: F_S = R_total / P_total; Where R_total is the total bearing capacity of all anchor bolts, which is obtained by calculation according to the method in the specification, and P_total is the total surrounding rock pressure calculated. For parameter combination optimization and decision-making, all parameter combinations are traversed, all schemes that meet the safety constraints are screened out, and the scheme with the lowest total cost is selected as the optimal cavern anchor scheme.

2. The method for decision-making and optimization of support schemes for deep ultra-large span tunnels based on critical sections according to claim 1, characterized in that, When the overall stability result of the deep ultra-large span cavern is good, local stability control is implemented. The steps for decision-making and optimization of the support scheme for the deep ultra-large span cavern include: The local damage of deep, ultra-large span caverns is analyzed and the anchor bolt parameters are designed. The block theory or discrete element method is used to identify and calculate the stability of key blocks on the cavern surface that may be unstable. Based on the calculation results, the anchor bolt parameters of the cavern are designed. The total anti-sliding force provided by the anchor bolts is calculated using the anchor bolt parameters of the cavern. The cavern safety factor is then calculated based on the ratio of the total anti-sliding force provided by the anchor bolts to the total sliding force of the key blocks. This cavern safety factor is compared with the minimum design safety factor of the cavern. When the cavern safety factor is greater than the minimum design safety factor, it is taken as the total safety factor of the cavern. The cavern support scheme is then decided and optimized based on the total safety factor.

3. The method for decision-making and optimization of support schemes for deep ultra-large span tunnels based on critical sections according to claim 1, characterized in that, To obtain the optimal anchor bolt scheme for the cavern, the specific steps also include: Determine if an optimal anchor bolt scheme for the cavern exists. If it does, adopt the scheme, and its safety factor F_S is the total safety factor; the design is then complete. If it does not exist, the process enters the active support design phase, which includes the following steps: Prestressed anchor cables are used as the main support method. Based on the surrounding rock pressure, the tonnage, length and spacing of the prestressed anchor cables are designed, and they are supplemented with optimized cavern anchors and steel arches to form a composite support system. The composite support system is verified by numerical simulation, and its overall safety factor F_S is calculated using numerical simulation. If the safety factor F_S is not less than the design minimum safety factor F_S_min, then the optimal anchor bolt scheme for the cavern is designed.

4. An electronic device, characterized in that, include: One or more processors; Memory, used to store one or more programs; When the one or more programs are executed by the one or more processors, the one or more processors implement the method for decision-making and optimization of support schemes for deep ultra-large span tunnels based on critical sections as described in any one of claims 1 to 3.

5. A computer-readable medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps in the method for decision-making and optimization of support schemes for deep ultra-large span tunnels based on critical cross sections as described in any one of claims 1 to 3.

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