Weathered tuff contains silt tunnel large deformation analysis control method and system

Abstract

The application discloses a weathered tuff silty soil tunnel large deformation analysis control method and system, and the method comprises the following steps: constructing a basic finite element model; obtaining the volume of the plastic zone after excavation as a basic volume and a reference volume; selecting the parameters of each advanced support according to the basic volume and the reference volume, and simulating the excavation of the basic finite element model by using at least two advanced supports with the selected parameters to obtain the volume of the plastic zone after excavation as a check volume; when the difference between the check volume and a preset expected volume is less than a preset value, the currently selected advanced support and the parameters of the advanced support are used as the advanced support scheme for construction. The application can effectively select the parameters of the advanced support means, especially for the advanced support means with two or more parameter combinations, and has good adaptability; and the scientificity of the construction parameter selection of the weathered tuff silty soil tunnel is greatly improved, and the safety of the tunnel construction is improved.

Description

Technical Field

[0001] This invention relates to the field of intelligent analysis technology, specifically to a method and system for analyzing and controlling large deformations in tunnels made of weathered tuff containing silt. Background Technology

[0002] Research on large deformation tunnels in tuff, as well as their construction methods and parameters, remains insufficient. This is likely because the engineering mechanical properties of tuff are significantly affected by the degree of weathering. Typically, tunnels crossing unweathered tuff strata do not experience large deformations, but rather when crossing weathered tuff strata. Unweathered or weakly weathered tuff has high strength, resulting in strong self-stabilizing ability of the surrounding rock after tunnel excavation, and no large deformations were observed in the on-site construction sections. However, strongly weathered tuff has low strength, sometimes even making sampling difficult, and is classified as extremely soft rock. After tunnel excavation, its self-stabilizing ability is poor, leading to large deformations in the on-site construction sections.

[0003] For tuff tunnels with large deformation, it is necessary to reinforce the surrounding rock through advanced support methods in order to improve construction safety. However, there are many types of advanced support methods, and it is difficult to choose the corresponding parameters. Therefore, how to select the parameters of advanced support methods has become a problem. Summary of the Invention

[0004] In order to at least overcome the above-mentioned deficiencies in the prior art, the purpose of this application is to provide a method and system for analyzing and controlling large deformations in tunnels made of weathered tuff containing silt.

[0005] In a first aspect, embodiments of this application provide a method for analyzing and controlling large deformations in tunnels made of weathered tuff containing silt, including: Obtain the surrounding rock parameters of the target tunnel, and construct the basic finite element model of the target tunnel based on the surrounding rock parameters; The foundation finite element model was used to simulate the excavation of the foundation using basic support, and the volume of the plastic zone after excavation was obtained as the foundation volume. Excavation simulations were performed on the finite element model of the foundation with the same foundation support using multiple sets of different parameter conditions for advanced support, and the volume of the plastic zone after excavation corresponding to different advanced support under different parameter conditions was obtained as a reference volume. Based on the foundation volume and the reference volume, select the parameters for each type of advanced support, and use at least two advanced supports with the selected parameters to perform excavation simulation on the foundation finite element model to obtain the volume of the plastic zone after excavation as the verification volume. When the difference between the verified volume and the preset expected volume is less than the preset value, the currently selected advanced support and the parameters of the advanced support are used as the advanced support scheme for construction.

[0006] In one possible implementation, obtaining the reference volume includes: Pre-support methods include small-diameter pipe support and medium-diameter pipe roof support. Multiple working conditions are constructed by using the longitudinal spacing and circumferential spacing of the advanced small pipe support as variables, and the basic finite element model is excavated and simulated using advanced small pipe support under different working conditions to obtain multiple first reference volumes corresponding to different working conditions. Multiple working conditions are constructed by using the circumferential spacing of the central pipe roof support as a variable, and the excavation simulation of the basic finite element model is carried out through the central pipe roof support under different working conditions to obtain multiple second reference volumes corresponding to different working conditions. The first reference volume and the second reference volume are used as the reference volume.

[0007] In one possible implementation, selecting the parameters for each type of advanced support based on the base volume and the reference volume includes: The ratio of the base volume to the expected volume is calculated as the base ratio, and the ratio of the base volume to the reference volume for each parameter condition of each type of advanced support is calculated as the reference ratio. The basic ratio is allocated to each of the advanced supports to form a selected ratio, and the parameter condition corresponding to the reference ratio that is closest to the selected ratio is selected as the selected working condition. The parameters corresponding to the selected working condition are used as the parameters for each type of advanced support.

[0008] In one possible implementation, allocating the base ratio to each of the advanced supports to form a selected ratio includes: The selected ratio is obtained by performing an exponential operation based on the base ratio; the exponent of the exponential operation is the reciprocal of the number of types of advanced support.

[0009] In one possible implementation, the foundation support employs at least one of shotcrete, steel arch, and anchor bolts.

[0010] Secondly, embodiments of this application also provide a large deformation analysis and control system for tunnels made of weathered tuff containing silt, including: The modeling unit is configured to acquire the surrounding rock parameters of the target tunnel and construct a basic finite element model of the target tunnel based on the surrounding rock parameters; The basic unit is configured to simulate the excavation of the foundation finite element model using foundation support and obtain the volume of the plastic zone after excavation as the foundation volume. The reference unit is configured to perform excavation simulation on the finite element model of the foundation with the same foundation support using multiple sets of different parameter conditions for different advance support, and obtain the excavated plastic zone volume corresponding to different advance supports under different parameter conditions as the reference volume. The selection unit is configured to select parameters for each type of advanced support based on the foundation volume and the reference volume, and to perform excavation simulation on the foundation finite element model using at least two advanced supports with the selected parameters to obtain the volume of the plastic zone after excavation as the verification volume. The verification unit is configured to use the currently selected advanced support and its parameters as the advanced support scheme for construction when the difference between the verification volume and the preset expected volume is less than a preset value.

[0011] In one possible implementation, the reference unit is further configured as follows: Pre-support methods include small-diameter pipe support and medium-diameter pipe roof support. Multiple working conditions are constructed by using the longitudinal spacing and circumferential spacing of the advanced small pipe support as variables, and the basic finite element model is excavated and simulated using advanced small pipe support under different working conditions to obtain multiple first reference volumes corresponding to different working conditions. Multiple working conditions are constructed by using the circumferential spacing of the central pipe roof support as a variable, and the excavation simulation of the basic finite element model is carried out through the central pipe roof support under different working conditions to obtain multiple second reference volumes corresponding to different working conditions. The first reference volume and the second reference volume are used as the reference volume.

[0012] In one possible implementation, the selection unit is further configured as follows: The ratio of the base volume to the expected volume is calculated as the base ratio, and the ratio of the base volume to the reference volume for each parameter condition of each type of advanced support is calculated as the reference ratio. The basic ratio is allocated to each of the advanced supports to form a selected ratio, and the parameter condition corresponding to the reference ratio that is closest to the selected ratio is selected as the selected working condition. The parameters corresponding to the selected working condition are used as the parameters for each type of advanced support.

[0013] In one possible implementation, the selection unit is further configured as follows: The selected ratio is obtained by performing an exponential operation based on the base ratio; the exponent of the exponential operation is the reciprocal of the number of types of advanced support.

[0014] In one possible implementation, the foundation support employs at least one of shotcrete, steel arch, and anchor bolts.

[0015] Compared with the prior art, the present invention has the following advantages and beneficial effects: The present invention provides a method and system for analyzing and controlling large deformations in tunnels made of weathered tuff containing silt. This method can effectively select relevant parameters for advanced support methods, and has good adaptability, especially for advanced support methods with two or more parameter combinations. It greatly improves the scientific nature of selecting construction parameters for tunnels made of weathered tuff containing silt, thereby improving the safety of tunnel construction. Attached Figure Description

[0016] The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and form part of this application, do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the method steps in an embodiment of this application; Figure 2 This is a schematic diagram of the basic finite element model for an embodiment of this application; Figure 3 This is a schematic diagram of the plastic region in an embodiment of this application. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. It should be understood that the accompanying drawings in this application are for illustrative and descriptive purposes only and are not intended to limit the scope of protection of this application. Furthermore, it should be understood that the schematic drawings are not drawn to scale. The flowcharts used in this application illustrate operations implemented according to some embodiments of this application. It should be understood that the operations in the flowcharts may not be implemented in sequence, and steps without logical contextual relationships may be reversed or implemented simultaneously. In addition, those skilled in the art, guided by the content of this application, may add one or more other operations to the flowcharts, or remove one or more operations from the flowcharts.

[0018] Furthermore, the described embodiments are merely some, not all, of the embodiments of this application. The components of the embodiments of this application described and illustrated herein can typically be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0019] Please refer to the following: Figure 1 This is a flowchart illustrating the method for analyzing and controlling large deformations in a weathered tuff-silt tunnel provided in this embodiment of the invention. Further, the method for analyzing and controlling large deformations in a weathered tuff-silt tunnel may specifically include the contents described in steps S1-S5.

[0020] S1: Obtain the surrounding rock parameters of the target tunnel, and construct the basic finite element model of the target tunnel based on the surrounding rock parameters; S2: The foundation finite element model is used to simulate excavation using basic support, and the volume of the plastic zone after excavation is obtained as the foundation volume; S3: Using multiple sets of different parameter conditions for advanced support, the finite element model of the foundation with the same foundation support is used to perform excavation simulation, and the volume of the plastic zone after excavation corresponding to different advanced support under different parameter conditions is obtained as a reference volume. S4: Select the parameters for each type of advanced support according to the foundation volume and the reference volume, and perform excavation simulation on the foundation finite element model using at least two advanced supports with the selected parameters to obtain the volume of the plastic zone after excavation as the verification volume; S5: When the difference between the verified volume and the preset expected volume is less than the preset value, the currently selected advanced support and the parameters of the advanced support are used as the advanced support scheme selected for construction.

[0021] In implementing this embodiment, it is first necessary to obtain relevant surrounding rock samples by sampling the target tunnel on-site, and then obtain the corresponding parameters of these surrounding rock samples under laboratory conditions, thereby constructing a basic finite element model. This model can be constructed using existing commercial finite element methods such as ANSYS and FLAC3D; this embodiment does not impose any limitations. It should be understood that, for the convenience of subsequent calculations, the basic finite element model should include the foundation support, excavation steps, and various advanced support structures, which can be activated as needed.

[0022] In this embodiment of the application, when using foundation support for excavation simulation, the excavation method needs to be considered. This method should be taken into account during modeling and configured accordingly in the foundation finite element model, such as the three-step method or the two-step method. Foundation support refers to the initial support during tunnel construction, which generally includes shotcrete, steel mesh, anchor bolts, steel arches, etc. After calculation using this scheme, the volume of the plastic zone after excavation can be obtained, which is used to characterize the volume of the plastic zone without advance support. The essence of advance support is to reduce the volume of this plastic zone, thereby achieving surrounding rock stability.

[0023] In this embodiment, for the same basic finite element model, under the condition of construction and loading of foundation support, corresponding advanced support is added for calculation. Each type of advanced support is calculated independently, and different parameters of the advanced support can be selected for each calculation. Multiple reference volumes corresponding to different parameter conditions can be obtained for each type of advanced support through finite element calculation. It should be understood that for single-parameter advanced support, each parameter condition corresponds to one parameter value; for advanced support with at least two parameters, orthogonal parameter combinations are required, with each condition corresponding to one parameter combination.

[0024] In this embodiment, the difference between the base volume and the reference volume allows for the selection of advanced support. It should be understood that an optimization target, the expected volume, needs to be set in advance. This volume characterizes the volume of the plastic zone that ensures safe tunnel construction under the combined action of advanced and base support. When selecting parameters using the base and reference volumes, the ultimate goal is to choose suitable parameters so that the combined effect of at least two types of advanced and base support ultimately brings the plastic zone volume close to the expected volume. After selecting the parameters, a finite element model is used to verify the advanced support corresponding to these parameters, and the safety of the scheme is determined based on the calculated verification volume. In this embodiment, if the difference between the calculated verification volume and the expected volume is less than a preset value, it indicates that the scheme meets the safety requirements of tunnel construction, and the parameters and advanced support scheme corresponding to this scheme can then be applied in construction.

[0025] In one possible implementation, obtaining the reference volume includes: Pre-support methods include small-diameter pipe support and medium-diameter pipe roof support. Multiple working conditions are constructed by using the longitudinal spacing and circumferential spacing of the advanced small pipe support as variables, and the basic finite element model is excavated and simulated using advanced small pipe support under different working conditions to obtain multiple first reference volumes corresponding to different working conditions. Multiple working conditions are constructed by using the circumferential spacing of the central pipe roof support as a variable, and the excavation simulation of the basic finite element model is carried out through the central pipe roof support under different working conditions to obtain multiple second reference volumes corresponding to different working conditions. The first reference volume and the second reference volume are used as the reference volume.

[0026] In implementing this application embodiment, considering the characteristics of tuff tunnels, two options for advance support are selected: advance small pipe support and central pipe roof support. Advance small pipe support has two parameter variables: longitudinal spacing and circumferential spacing; while central pipe roof support has one parameter variable: circumferential spacing. At this time, the two parameter variables of advance small pipe support are orthogonally combined to form multiple working conditions, while the parameter variables of central pipe roof support are linearly and equally spaced to form multiple working conditions; and then the corresponding reference volume is calculated.

[0027] In one possible implementation, selecting the parameters for each type of advanced support based on the base volume and the reference volume includes: The ratio of the base volume to the expected volume is calculated as the base ratio, and the ratio of the base volume to the reference volume for each parameter condition of each type of advanced support is calculated as the reference ratio. The basic ratio is allocated to each of the advanced supports to form a selected ratio, and the parameter condition corresponding to the reference ratio that is closest to the selected ratio is selected as the selected working condition. The parameters corresponding to the selected working condition are used as the parameters for each type of advanced support.

[0028] In one possible implementation, allocating the base ratio to each of the advanced supports to form a selected ratio includes: The selected ratio is obtained by performing an exponential operation based on the base ratio; the exponent of the exponential operation is the reciprocal of the number of types of advanced support.

[0029] In implementing this application, the basic idea is to allocate the basic proportion to each type of advanced support, with each advanced support independently fulfilling its corresponding proportion. It should be understood that although there may be coupling effects between different advanced supports, these effects are generally less pronounced than the advanced supports themselves, and these coupling effects are generally positive combined effects with a positive impact on tunnel construction safety. Based on this idea, this application can allocate the corresponding basic proportions. During allocation, the basic proportions can be divided into multiple parts. The specific division method can be equal distribution or allocation based on the corresponding weights of different advanced supports. This application prefers equal distribution. After equal distribution of the basic proportions, the parameter corresponding to the reference proportion closest to and greater than the selected proportion is selected as the parameter actually used; the final result is the parameter corresponding to each advanced support. For the basic proportion allocation process, the basic proportion needs to be decomposed into multiple product-valued selected proportions. For the equal distribution process, this is equivalent to taking the square root of the basic proportion, with the number of square roots equal to the number of types of advanced supports.

[0030] For example, this application provides a specific implementation method, which is applied to a railway tunnel in western China. The tunnel is 8356.2m long. According to indoor tests, the elastic modulus of the weathered tuff in its natural state is 3.35GPa, the cohesion is 8.36MPa, the internal friction angle is 15.23°, and the Poisson's ratio is 0.30. After soaking in water, the elastic modulus of the weathered tuff is 2.58GPa, the cohesion is 3.55MPa, the internal friction angle is 26.09°, and the Poisson's ratio is 0.31. Numerical calculations were performed on the section from DK181+582 to DK181+666m. The model boundary was set to 3-5 times the tunnel diameter based on Saint-Venant's principle. Considering that tunnel deformation at the junction of different support types during construction might be affected by the support type of the already excavated section, the numerical model was designed with a 72m middle section removed from the beginning and end. Therefore, the model dimensions were determined to be 136m × 97m × 72m. The final finite element model is shown below. Figure 2 Two advanced support methods were selected for the calculations: advanced small-diameter pipe support and central pipe roof support. The two parameter combinations for advanced small-diameter pipe support resulted in 25 working conditions, while the two for central pipe roof support resulted in 8 working conditions. After calculation and analysis of these various working conditions, the final selected parameters for advanced small-diameter pipe support were a longitudinal spacing of 2.4m and a circumferential spacing of 0.4m; the final parameter for central pipe roof support was a circumferential spacing of 0.4m. The results of their independent and combined calculations are shown below. Figure 3 This shows that the volume of the plastic zone after excavation is 1680.61 m³ for tunnels using only pre-excavated small-diameter pipe supports, and 1634.26 m³ for tunnels using only central pipe roof supports. 3 The volume of the plastic zone after excavation for the tunnel supported by small guide pipes and medium-diameter pipe roof was 1431.86 m³. 3 .

[0031] In one possible implementation, the foundation support employs at least one of shotcrete, steel arch, and anchor bolts.

[0032] Based on the same inventive concept, embodiments of this application also provide a large deformation analysis and control system for tunnels made of weathered tuff containing silt, including: The modeling unit is configured to acquire the surrounding rock parameters of the target tunnel and construct a basic finite element model of the target tunnel based on the surrounding rock parameters; The basic unit is configured to simulate the excavation of the foundation finite element model using foundation support and obtain the volume of the plastic zone after excavation as the foundation volume. The reference unit is configured to perform excavation simulation on the finite element model of the foundation with the same foundation support using multiple sets of different parameter conditions for different advance support, and obtain the excavated plastic zone volume corresponding to different advance supports under different parameter conditions as the reference volume. The selection unit is configured to select parameters for each type of advanced support based on the foundation volume and the reference volume, and to perform excavation simulation on the foundation finite element model using at least two advanced supports with the selected parameters to obtain the volume of the plastic zone after excavation as the verification volume. The verification unit is configured to use the currently selected advanced support and its parameters as the advanced support scheme for construction when the difference between the verification volume and the preset expected volume is less than a preset value.

[0033] In one possible implementation, the reference unit is further configured as follows: Pre-support methods include small-diameter pipe support and medium-diameter pipe roof support. Multiple working conditions are constructed by using the longitudinal spacing and circumferential spacing of the advanced small pipe support as variables, and the basic finite element model is excavated and simulated using advanced small pipe support under different working conditions to obtain multiple first reference volumes corresponding to different working conditions. Multiple working conditions are constructed by using the circumferential spacing of the central pipe roof support as a variable, and the excavation simulation of the basic finite element model is carried out through the central pipe roof support under different working conditions to obtain multiple second reference volumes corresponding to different working conditions. The first reference volume and the second reference volume are used as the reference volume.

[0034] In one possible implementation, the selection unit is further configured as follows: The ratio of the base volume to the expected volume is calculated as the base ratio, and the ratio of the base volume to the reference volume for each parameter condition of each type of advanced support is calculated as the reference ratio. The basic ratio is allocated to each of the advanced supports to form a selected ratio, and the parameter condition corresponding to the reference ratio that is closest to the selected ratio is selected as the selected working condition. The parameters corresponding to the selected working condition are used as the parameters for each type of advanced support.

[0035] In one possible implementation, the selection unit is further configured as follows: The selected ratio is obtained by performing an exponential operation based on the base ratio; the exponent of the exponential operation is the reciprocal of the number of types of advanced support.

[0036] In one possible implementation, the foundation support employs at least one of shotcrete, steel arch, and anchor bolts.

[0037] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0038] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative. For instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed may be indirect coupling or communication connection through some interfaces, devices or units, or may be electrical, mechanical or other forms of connection.

[0039] The units described as separate components may or may not be physically separate. As will be apparent to those skilled in the art, the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0040] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0041] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or grid device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0042] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for analyzing and controlling large deformations in tunnels made of weathered tuff containing silt, characterized in that, include: Obtain the surrounding rock parameters of the target tunnel, and construct the basic finite element model of the target tunnel based on the surrounding rock parameters; The foundation finite element model was used to simulate the excavation of the foundation using basic support, and the volume of the plastic zone after excavation was obtained as the foundation volume. Excavation simulations were performed on the finite element model of the foundation with the same foundation support using multiple sets of different parameter conditions for advanced support, and the volume of the plastic zone after excavation corresponding to different advanced support under different parameter conditions was obtained as a reference volume. Based on the foundation volume and the reference volume, select the parameters for each type of advanced support, and use at least two advanced supports with the selected parameters to perform excavation simulation on the foundation finite element model to obtain the volume of the plastic zone after excavation as the verification volume. When the difference between the verified volume and the preset expected volume is less than the preset value, the currently selected advanced support and the parameters of the advanced support are used as the advanced support scheme for construction.

2. The method for analyzing and controlling large deformations in tunnels made of weathered tuff containing silt, as described in claim 1, is characterized in that... The acquisition of the reference volume includes: Pre-support methods include small-diameter pipe support and medium-diameter pipe roof support. Multiple working conditions are constructed by using the longitudinal spacing and circumferential spacing of the advanced small pipe support as variables, and the basic finite element model is excavated and simulated using advanced small pipe support under different working conditions to obtain multiple first reference volumes corresponding to different working conditions. Multiple working conditions are constructed by using the circumferential spacing of the central pipe roof support as a variable, and the excavation simulation of the basic finite element model is carried out through the central pipe roof support under different working conditions to obtain multiple second reference volumes corresponding to different working conditions. The first reference volume and the second reference volume are used as the reference volume.

3. The method for analyzing and controlling large deformations in tunnels made of weathered tuff containing silt, as described in claim 1, is characterized in that... The parameters for each type of advanced support are selected based on the base volume and the reference volume, including: The ratio of the base volume to the expected volume is calculated as the base ratio, and the ratio of the base volume to the reference volume for each parameter condition of each type of advanced support is calculated as the reference ratio. The basic ratio is allocated to each of the advanced supports to form a selected ratio, and the parameter condition corresponding to the reference ratio that is closest to the selected ratio is selected as the selected working condition. The parameters corresponding to the selected working condition are used as the parameters for each type of advanced support.

4. The method for analyzing and controlling large deformations in tunnels made of weathered tuff containing silt, as described in claim 3, is characterized in that... The allocation of the base ratio to each of the advanced support structures to form a selected ratio includes: The selected ratio is obtained by performing an exponential operation based on the base ratio; the exponent of the exponential operation is the reciprocal of the number of types of advanced support.

5. The method for analyzing and controlling large deformations in tunnels made of weathered tuff containing silt, as described in claim 1, is characterized in that... The foundation support uses at least one of shotcrete, steel arch frame and anchor bolts.

6. A large deformation analysis and control system for tunnels made of weathered tuff containing silt, characterized in that, include: The modeling unit is configured to acquire the surrounding rock parameters of the target tunnel and construct a basic finite element model of the target tunnel based on the surrounding rock parameters; The basic unit is configured to simulate the excavation of the foundation finite element model using foundation support and obtain the volume of the plastic zone after excavation as the foundation volume. The reference unit is configured to perform excavation simulation on the finite element model of the foundation with the same foundation support using multiple sets of different parameter conditions for different advance support, and obtain the excavated plastic zone volume corresponding to different advance supports under different parameter conditions as the reference volume. The selection unit is configured to select parameters for each type of advanced support based on the foundation volume and the reference volume, and to perform excavation simulation on the foundation finite element model using at least two advanced supports with the selected parameters to obtain the volume of the plastic zone after excavation as the verification volume. The verification unit is configured to use the currently selected advanced support and its parameters as the advanced support scheme for construction when the difference between the verification volume and the preset expected volume is less than a preset value.

7. The large deformation analysis and control system for weathered tuff-silt-bearing tunnels according to claim 6, characterized in that, The reference unit is also configured to: Pre-support methods include small-diameter pipe support and medium-diameter pipe roof support. Multiple working conditions are constructed by using the longitudinal spacing and circumferential spacing of the advanced small pipe support as variables, and the basic finite element model is excavated and simulated using advanced small pipe support under different working conditions to obtain multiple first reference volumes corresponding to different working conditions. Multiple working conditions are constructed by using the circumferential spacing of the central pipe roof support as a variable, and the excavation simulation of the basic finite element model is carried out through the central pipe roof support under different working conditions to obtain multiple second reference volumes corresponding to different working conditions. The first reference volume and the second reference volume are used as the reference volume.

8. The large deformation analysis and control system for weathered tuff-silt-bearing tunnels according to claim 6, characterized in that, The selection unit is further configured to: The ratio of the base volume to the expected volume is calculated as the base ratio, and the ratio of the base volume to the reference volume for each parameter condition of each type of advanced support is calculated as the reference ratio. The basic ratio is allocated to each of the advanced supports to form a selected ratio, and the parameter condition corresponding to the reference ratio that is closest to the selected ratio is selected as the selected working condition. The parameters corresponding to the selected working condition are used as the parameters for each type of advanced support.

9. The large deformation analysis and control system for weathered tuff-silt-bearing tunnels according to claim 8, characterized in that, The selection unit is further configured to: The selected ratio is obtained by performing an exponential operation based on the base ratio; the exponent of the exponential operation is the reciprocal of the number of types of advanced support.

10. The large deformation analysis and control system for weathered tuff-silt-bearing tunnels according to claim 6, characterized in that, The foundation support uses at least one of shotcrete, steel arch frame and anchor bolts.

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