A method and system for determining the range of damage characteristics of surrounding rock of a tunnel

Abstract

This application discloses a method and system for identifying the range of failure characteristics of surrounding rock in tunnels. It accurately identifies the range of various failure characteristics of the surrounding rock, which has significant theoretical and engineering implications for tunnel stability evaluation, support structure design, and construction safety control. The embodiments of this application are based on a quantitative method for identifying the failure characteristics of surrounding rock using plastic strain and volumetric energy dissipation rate. The loosening zone is defined by the Pearson correlation coefficient between plastic shear strain and volumetric strain; the boundary within the undisturbed zone is determined by the near-zero characteristic of the volumetric energy dissipation rate and its correlation coefficient, thereby accurately identifying the excavation influence range. A continuous and quantitative identification system from the loosening zone to the undisturbed zone is constructed, possessing a clear physical basis. It can reveal the spatiotemporal evolution law of the failure zone and provides a reliable basis for anchor bolt design, support optimization, and engineering stability assessment, combining theoretical innovation with engineering practicality.

Description

Technical Field

[0001] This application relates to, but is not limited to, the field of tunnel and underground engineering technology, and particularly to a method and system for determining the range of damage characteristics of surrounding rock in tunnels. Background Technology

[0002] In tunnels and underground engineering, rock excavation is a process of intense unloading, which disrupts the original rock stress balance, induces stress redistribution in the surrounding rock, and forms a secondary stress field centered on the tunnel chamber. This secondary stress field typically manifests as a significant decrease in radial stress, even to zero at the tunnel walls, while circumferential stress increases sharply and concentrates at a certain depth. Under this stress path, when the secondary stress exceeds the yield limit of the surrounding rock, the surrounding rock enters a plastic state and forms a plastic zone.

[0003] From the tunnel wall into the deeper rock mass, the impact of excavation on the surrounding rock decreases from strong to weak, generally passing through four zones in sequence. The loosened zone, located immediately adjacent to the tunnel wall, is most significantly affected by circumferential stress concentration, prone to shear slip or tensile failure, with numerous fissures initiating and connecting, resulting in a noticeably loose rock structure and significantly reduced self-stabilizing capacity. The plastic zone shows irreversible plastic deformation of the rock mass, but the overall structure is not completely broken, retaining some residual strength. The elastic zone exhibits only elastic response, with minimal permanent deformation. The undisturbed zone is almost unaffected by excavation, maintaining its original stress state, with various mechanical properties close to pre-excavation levels.

[0004] In engineering practice, accurately identifying the range of these damage characteristics, especially the boundary between the loosening zone and the plastic zone, as well as the limit boundary of the excavation disturbance range, is of great significance for tunnel stability evaluation, support structure (such as anchor bolts and lining) design, construction safety control, and long-term operational reliability. Summary of the Invention

[0005] This application provides a method and system for determining the range of damage characteristics of surrounding rock in tunnels. This method can continuously and quantitatively determine the range of damage characteristics of surrounding rock, thereby improving the accuracy and engineering applicability of surrounding rock zoning identification.

[0006] This invention provides a method for determining the range of tunnel surrounding rock failure characteristics, including: Multiple sets of mechanical response data distributed along the depth direction of the surrounding rock of the tunnel are obtained. Each set of mechanical response data includes: a first deformation index for characterizing the degree of irreversible deformation of the rock mass volume, a second deformation index for characterizing the degree of irreversible deformation of the rock mass shear, and an energy index for characterizing the degree of energy dissipation due to damage to the surrounding rock. The mechanical response data are obtained from engineering calculations or monitoring and analysis results during the tunnel excavation process. The depth of the plastic zone boundary is determined based on the distribution of the surrounding rock yield state along the depth direction in the mechanical response data. ; Data sequences of the first deformation index, the second deformation index, and the energy index as a function of the surrounding rock depth were established. A moving calculation window was set from the deep part of the surrounding rock toward the tunnel wall. The Pearson correlation coefficient between the index values ​​and the depth within the moving calculation window was calculated to obtain the correlation coefficient-depth curve of the first deformation index, the correlation coefficient-depth curve of the second deformation index, and the correlation coefficient-depth curve of the energy index. The locations of abrupt changes were identified in the correlation coefficient-depth curve of the first deformation index and the correlation coefficient-depth curve of the second deformation index, and the boundary depth of the loosened zone was determined based on the corresponding depths of the two curves. ; Identify abrupt changes in the energy index correlation coefficient-depth curve and determine the corresponding depth as the boundary depth of the excavation disturbance influence range. ; The extent of the plastic zone is determined based on the yielding state of the surrounding rock, and the depth of the loosened zone boundary is also determined. , depth of the plastic zone boundary Boundary of the excavation disturbance impact area If the preset physical constraints are met, output the result of the surrounding rock failure range determination; otherwise, return to step 100 until the preset physical constraints are met.

[0007] In one exemplary instance, the determination of the plastic zone boundary depth is based on the distribution of the surrounding rock yield state along the depth direction in the mechanical response data. ,include: Extract the surrounding rock yield state at each monitoring point along the selected observation path at the selected observation time. The monitoring path is traversed from the tunnel wall into the depth of the surrounding rock. When the depth corresponding to a monitoring point meets the preset yield condition, it is determined to be a plastic zone. The depth corresponding to the outermost edge of all monitoring points in the yield state is determined as the boundary depth of the plastic zone. ; The surrounding rock yield state is used to characterize whether the surrounding rock has entered the stage of irreversible deformation. When the surrounding rock meets the preset yield criterion, the depth position corresponding to the monitoring point is in the yield state of the surrounding rock and is determined to be in the plastic zone. When the preset yield criterion is not met, it is determined to be in the elastic state.

[0008] In one exemplary instance, obtaining the correlation coefficient-depth curve of the first deformation index, the correlation coefficient-depth curve of the second deformation index, and the correlation coefficient-depth curve of the energy index includes: Based on the values ​​of the first deformation index, the second deformation index, and the energy index at the corresponding depth positions of each monitoring point on the monitoring path, they are sorted in descending order of distance from the tunnel wall to construct the first deformation index-depth sequence, the second deformation index-depth sequence, and the energy index-depth sequence, respectively. The moving calculation window is set from the depth of the surrounding rock towards the tunnel wall on the constructed depth sequence. The moving calculation window covers multiple continuous monitoring points and moves towards the tunnel wall point by point along the monitoring path. At each position of the moving calculation window, the Pearson correlation coefficient PCC between the monitoring point depth as the independent variable and the index value corresponding to each monitoring point in the window as the dependent variable is calculated to obtain the first deformation index correlation coefficient-depth curve, the second deformation index correlation coefficient-depth curve and the energy index correlation coefficient-depth curve.

[0009] In one exemplary instance, when calculating the correlation coefficient of the first deformation index, the dependent variable is the plastic volumetric strain (PVS); when calculating the correlation coefficient of the second deformation index, the dependent variable is the plastic shear strain (PSS); and when calculating the correlation coefficient of the energy index, the dependent variable is the volumetric energy dissipation rate (VEDR).

[0010] In one exemplary instance, the abrupt change locations are identified in the first deformation index correlation coefficient-depth curve and the second deformation index correlation coefficient-depth curve, respectively, and the loosening zone boundary depth is determined based on their corresponding depths. ,include: The correlation coefficient-depth curve of the first deformation index and the correlation coefficient-depth curve of the second deformation index are traversed and calculated respectively, and the point where the Pearson correlation coefficient changes at the largest rate along the depth direction is determined as the abrupt change position. The mutation depth corresponding to the first deformation index is denoted as The mutation depth corresponding to the second deformation index is denoted as The depth of the loosening zone boundary is determined according to the following formula. : .

[0011] In one exemplary instance, the step of identifying abrupt change locations in the energy index correlation coefficient-depth curve and determining the corresponding depth as the boundary depth of the excavation disturbance influence range is described. ,include: The correlation coefficient-depth curve of the energy index is traversed and calculated to determine the point where the Pearson correlation coefficient changes at the largest rate along the depth direction as the abrupt change location, and the corresponding depth is determined as the boundary depth of the excavation disturbance influence range. .

[0012] In one exemplary instance, the preset physical constraint condition includes: the depth of the loosening zone boundary. Less than the depth of the plastic zone boundary And the depth of the plastic zone boundary Smaller than the boundary of the excavation disturbance influence range : .

[0013] This application also provides a computer-readable storage medium storing computer-executable instructions, which are used to execute the method for determining the range of tunnel surrounding rock damage characteristics described in any of the above embodiments.

[0014] This application embodiment further provides a computer device, including a memory and a processor, wherein the memory stores the following instructions executable by the processor: steps for performing the method for determining the range of tunnel surrounding rock damage characteristics as described in any of the above claims.

[0015] This application embodiment also provides a system for determining the range of damage characteristics of surrounding rock in tunnels, including: an acquisition module, a first determination module, a processing module, a second determination module, a third determination module, and a discrimination module; The acquisition module is used to acquire multiple sets of mechanical response data distributed along the depth direction of the surrounding rock of the tunnel. Each set of mechanical response data includes: a first deformation index for characterizing the degree of irreversible deformation of the rock mass volume, a second deformation index for characterizing the degree of irreversible deformation of the rock mass shear, and an energy index for characterizing the degree of energy dissipation due to damage to the surrounding rock. The mechanical response data are obtained from engineering calculations or monitoring and analysis results during the tunnel excavation process. The first determining module is used to determine the boundary depth of the plastic zone based on the distribution of the yield state of the surrounding rock along the depth direction in the mechanical response data. The processing module is used to establish data sequences of the first deformation index, the second deformation index, and the energy index as the surrounding rock depth changes, and to set a moving calculation window from the deep part of the surrounding rock towards the tunnel wall to calculate the Pearson correlation coefficient between the index value and the depth within the moving calculation window, thereby obtaining the correlation coefficient-depth curve of the first deformation index, the correlation coefficient-depth curve of the second deformation index, and the correlation coefficient-depth curve of the energy index. The second determining module is used to identify abrupt change locations in the first deformation index correlation coefficient-depth curve and the second deformation index correlation coefficient-depth curve, respectively, and determine the boundary depth of the loosened zone based on the corresponding depths of the two curves. ; The third determination module is used to identify abrupt change locations in the energy index correlation coefficient-depth curve and determine the corresponding depth as the boundary depth of the excavation disturbance influence range. ; The discrimination module is used to determine the extent of the plastic zone based on the yielding state of the surrounding rock and to determine the depth of the loosened zone boundary. , depth of the plastic zone boundary Boundary of the excavation disturbance impact area If the preset physical constraints are met, output the result of the surrounding rock failure range determination; otherwise, return to the processing of the acquisition module until the preset physical constraints are met.

[0016] The method for determining the range of tunnel surrounding rock failure characteristics provided in this application accurately identifies the range of each failure characteristic, which has significant theoretical and engineering implications for tunnel stability evaluation, support structure design, and construction safety control. This application's method, based on a quantitative determination of surrounding rock failure characteristics using plastic strain and volumetric energy dissipation rate, defines the loosened zone through the Pearson correlation coefficient between plastic shear strain and volumetric strain; it uses the near-zero characteristic of the volumetric energy dissipation rate and its correlation coefficient to determine the boundary within the undisturbed zone, thereby accurately identifying the excavation influence range. The method for determining the range of tunnel surrounding rock failure characteristics provided in this application constructs a continuous and quantitative determination system from the loosened zone to the undisturbed zone, possessing a clear physical basis. It can reveal the spatiotemporal evolution law of the failure zone and provides a reliable basis for anchor bolt design, support optimization, and engineering stability assessment, combining theoretical innovation with engineering practicality.

[0017] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the description, claims, and drawings. Attached Figure Description

[0018] The accompanying drawings are used to provide a further understanding of the technical solutions of this application and constitute a part of the specification. They are used together with the embodiments of this application to explain the technical solutions of this application and do not constitute a limitation on the technical solutions of this application.

[0019] Figure 1 This is a flowchart of the method for determining the range of tunnel surrounding rock failure characteristics in the embodiments of this application; Figure 2 This is a schematic flowchart of an embodiment of the method for determining the range of tunnel surrounding rock failure characteristics in this application. Figure 3 This is a schematic diagram illustrating the range of surrounding rock damage characteristics induced by tunnel excavation in an embodiment of this application; Figure 4 This is a schematic diagram of the three-dimensional numerical simulation model of the tunnel in the embodiments of this application; Figure 5 This is a schematic diagram of the surrounding rock failure characteristic range discrimination index and curve in the embodiments of this application; Figure 6 This is a schematic diagram illustrating an example of determining the range of loosening zones based on the plastic shear strain index in an embodiment of this application. Figure 7This is a schematic diagram illustrating an example of determining the range of loosening zones based on the plastic volumetric strain index in an embodiment of this application. Figure 8 This is an example schematic diagram illustrating the determination of the boundary of the undisturbed region based on the volumetric energy dissipation rate index in an embodiment of this application; Figure 9 This is a schematic diagram illustrating an example of the distribution of the plastic zone in the surrounding rock after tunnel excavation in an embodiment of this application. Figure 10 This is a schematic diagram of the composition of the system for determining the range of tunnel surrounding rock damage characteristics in this embodiment of the application. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in detail below with reference to the accompanying drawings. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be arbitrarily combined with each other.

[0021] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings, which illustrate embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this application will be thorough and complete.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0023] It is understood that the terms "first" and "second" used in this application are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0024] It is understood that the term "connection" in the following embodiments should be understood as "electrical connection," "communication connection," etc., if the connected circuits, modules, units, etc., have electrical signal or data transmission with each other.

[0025] When used herein, the singular forms of “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising / including” or “having,” etc., specify the presence of the stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. Meanwhile, the term “and / or” as used in this specification includes any and all combinations of the associated listed items.

[0026] The steps illustrated in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases the steps shown or described may be performed in a different order than that presented here.

[0027] In engineering practice, the most commonly used method for determining the extent of loosened zones is borehole acoustic wave velocity testing. This method is based on the correlation between rock mass wave velocity and its integrity and density. By obtaining the spatial distribution of elastic wave velocity in the borehole, areas with significantly reduced wave velocity are interpreted as regions of rock relaxation and fracture development, thereby inverting and delineating the boundary of the loosened zone. However, this type of in-situ testing method is subject to significant construction interference, has a long testing cycle, and is costly. Furthermore, due to the limited number of testing points, the spatial continuity and representativeness of the results are insufficient. In addition, the testing accuracy is easily affected by complex factors such as drilling technology, groundwater conditions, and rock mass anisotropy, limiting the accuracy and stability of the determination results.

[0028] Numerical simulation methods can overcome the aforementioned shortcomings of field testing to some extent; however, a unified and clearly defined physical criterion for determining failure is still lacking. Correlation analyses typically rely on a single mechanical index for judgment, such as determining the extent of the plastic zone by whether the Mohr-Coulomb or Hoek-Brown strength criteria are met, or judging large deformation failure of the surrounding rock by the displacement exceeding an empirical threshold. While these methods can provide a rough estimate of the plastic zone, they struggle to further distinguish between the severely loosened zone, which has essentially lost its self-stabilizing ability, and the plastic zone, which still possesses residual bearing capacity.

[0029] Furthermore, existing criteria for determining the ultimate boundary of the excavation disturbance range, i.e., the inner boundary of the undisturbed zone, often lack clear and unified methods, relying heavily on empirical thresholds. Since these thresholds vary with cavern size, depth, and rock mechanics parameters, their determination is highly subjective and unstable, leading to discrepancies between numerical analysis results and actual engineering conditions. This limits the reliability of support design and engineering optimization.

[0030] Therefore, there is an urgent need for a method with a clear physical basis that can continuously and quantitatively determine the range of surrounding rock damage characteristics in order to improve the accuracy and engineering applicability of surrounding rock zoning identification.

[0031] Therefore, this application provides a method for determining the range of tunnel surrounding rock failure characteristics, combined with... Figure 1 , Figure 2 As shown, it may include: Step 100: Obtain multiple sets of mechanical response data distributed along the depth direction of the surrounding rock of the tunnel. Each set of mechanical response data includes: a first deformation index for characterizing the degree of irreversible deformation of the rock mass volume, a second deformation index for characterizing the degree of irreversible deformation of the rock mass shear, and an energy index for characterizing the degree of energy dissipation due to damage to the surrounding rock. The mechanical response data are obtained from engineering calculations or monitoring and analysis results during the tunnel excavation process.

[0032] In one exemplary instance, the first deformation index may include plastic volumetric strain (PVS); the second deformation index may include plastic shear strain (PSS); and the third deformation index may include volumetric energy dissipation rate (VEDR).

[0033] In one exemplary instance, mechanical response data can be obtained by establishing a three-dimensional time-dependent numerical analysis model of the surrounding rock of a tunnel and simulating the step-by-step excavation process of the tunnel. The mechanical response data in this embodiment comes from a real engineering calculation process and takes into account the changes over time after excavation (creep / relaxation / damage development), reflecting the mechanical response results of the surrounding rock evolving over time after excavation.

[0034] In one embodiment, the three-dimensional time-dependent numerical analysis model can employ a creep constitutive model based on the theory of internal variable thermodynamics to describe the viscoplastic deformation and damage evolution behavior of the surrounding rock during loading and unloading, and to calculate energy dissipation-related parameters accordingly. The three-dimensional time-dependent numerical analysis model not only calculates elastoplasticity but also reflects damage and energy dissipation over time, giving energy indicators physical meaning rather than purely empirical quantities.

[0035] In one embodiment, a monitoring path can be laid out along the normal direction of the tunnel wall from the tunnel wall to the depth of the surrounding rock on the tunnel cross section, and multiple monitoring points can be set on the path to obtain mechanical response data at different depths.

[0036] In one embodiment, obtaining mechanical response data by establishing a three-dimensional time-dependent numerical analysis model of the surrounding rock of the tunnel may include: First, engineering parameters are collected, which may include, but are not limited to, tunnel depth, cross-sectional shape and size, excavation advance and support scheme, as well as geological and mechanical parameters such as rock density, elastic modulus, Poisson's ratio, cohesion, internal friction angle and geostress field. Based on the collected engineering parameters, a three-dimensional numerical simulation model is established. In one embodiment, the boundary of the three-dimensional numerical simulation model is not less than 3-5 times the tunnel diameter from the center of the tunnel to reduce the impact of boundary effects on the calculation results. Subsequently, the area around the tunnel is divided into finer grids, which are gradually thickened towards the depth of the surrounding rock to ensure that stress and strain gradients can be accurately captured; preferably, the calculation results are verified to be insensitive to grid density through grid convergence analysis. Then, a creep constitutive model based on the internal variable thermodynamics theory is used in the three-dimensional numerical simulation model to describe the viscoplastic deformation and damage evolution behavior of the surrounding rock under excavation and unloading conditions, and the volumetric energy dissipation rate is calculated accordingly, so that the energy index has a clear physical meaning. Subsequently, numerical calculations were performed for step-by-step excavation according to the construction sequence. During the calculation process, the surrounding rock was discretized into multiple grid blocks and mechanical solutions were performed. In each calculation step, the PVS, PSS, VEDR and yield state of the surrounding rock at the spatial location of each grid block were obtained. Finally, a monitoring path is laid out along the tunnel wall normal direction from the tunnel wall to the depth of the surrounding rock on the tunnel cross section, and multiple monitoring points are set on the monitoring path to extract mechanical response data at the corresponding depth position of each monitoring point, so as to obtain a continuous distribution of surrounding rock mechanical response data sequence along the depth direction.

[0037] Step 100 systematically collected and organized basic data for the tunnel engineering, mainly including two aspects: First, the tunnel's structural design parameters, such as its burial depth, cross-sectional shape (e.g., circular, archway-shaped, etc.), and geometric dimensions, as well as the proposed excavation advance and support scheme; Second, detailed geological exploration and rock mechanics test results, covering the lithological distribution of the strata in the project area, the occurrence and mechanical properties of key geological structures (e.g., faults, joints, and fissures), measured data or reliable inversion results of the geostress field, and physical and mechanical parameters of the rock mass and structural surfaces (e.g., density, elastic modulus, Poisson's ratio, cohesion, internal friction angle, etc.). Based on this complete collection of engineering data, a three-dimensional numerical simulation model of the tunnel was established. The geometric dimensions of the three-dimensional numerical simulation model are large enough (e.g., the distance from the boundary to the center of the tunnel is not less than 3-5 times the tunnel diameter), eliminating boundary effects and ensuring that excavation disturbances can fully develop within the model without being restricted by the boundary. Meanwhile, given that the stress redistribution, plastic zone, and loosening zone development of the surrounding rock are highly concentrated around the cavern, targeted mesh refinement was implemented in this area, a key measure to ensure computational accuracy. The peri-cavity mesh maintained a high density, with the mesh size gradually increasing from the cave wall into the deeper rock mass. This allowed for the accurate capture of the stress and strain fields with drastic gradient changes around the cavern, and also enabled the dense deployment of numerical monitoring points along specific paths (such as radial paths). This enabled the extraction of physical quantities such as PVS, PSS, and VEDR with high spatial resolution, providing detailed and continuous data support for subsequent accurate boundary determination based on statistical methods.

[0038] Step 101: Determine the boundary depth of the plastic zone based on the distribution of the surrounding rock yield state along the depth direction in the mechanical response data. .

[0039] In one exemplary instance, step 101 may include: At the selected observation time, the yield state of the surrounding rock at each monitoring point along the monitoring path is extracted. The monitoring path is then traversed from the tunnel wall towards the depth of the surrounding rock. When the depth corresponding to a monitoring point meets the preset yield condition, it is determined to be a plastic zone. The depth corresponding to the outermost position of all monitoring points in the yield state (i.e., the depth corresponding to the last position in the yield state of the surrounding rock along the monitoring path from the tunnel wall towards the depth of the surrounding rock) is determined as the boundary depth of the plastic zone. Depth of the plastic zone boundary Used as a reference standard for subsequent judgment of reasonableness.

[0040] In one embodiment, the yield state of the surrounding rock is used to characterize whether the surrounding rock has entered the stage of irreversible deformation. When the surrounding rock meets the preset yield criterion, the depth location corresponding to the monitoring point is in the yield state of the surrounding rock and is determined to be in the plastic zone; when the preset yield criterion is not met, it is determined to be in the elastic state.

[0041] In one exemplary instance, the yield state of the surrounding rock can be directly obtained from the calculation results of the step-by-step excavation numerical calculation. In one embodiment, the yield state of the surrounding rock can be given by the determination results that satisfy, but are not limited to, the Mohr-Coulomb strength criterion, the Hoek-Brown strength criterion, or other rock mass strength criteria.

[0042] In one embodiment, the observation time is a preset time point after the excavation is completed, such as 24 hours after the excavation; in other embodiments, the observation time may also be the time when the tunnel support is completed or when the deformation of the surrounding rock tends to stabilize.

[0043] In one embodiment, the plastic zone boundary depth obtained through step 101 It serves as the spatial boundary for the surrounding rock to enter the irreversible plastic deformation zone, and as a physical reference benchmark for subsequent determination of the loosened zone boundary and the disturbance range boundary.

[0044] Step 102: Establish data sequences of the first deformation index, the second deformation index, and the energy index as a function of the surrounding rock depth, and set a moving calculation window from the deep part of the surrounding rock towards the tunnel wall. Calculate the Pearson correlation coefficient between the index values ​​and the depth within the moving calculation window to obtain the correlation coefficient-depth curve of the first deformation index, the correlation coefficient-depth curve of the second deformation index, and the correlation coefficient-depth curve of the energy index.

[0045] In one exemplary instance, step 102 may include: Based on the values ​​of the first deformation index, the second deformation index, and the energy index at the corresponding depth positions of each monitoring point on the monitoring path, they are sorted in descending order of distance from the tunnel wall, and the first deformation index-depth sequence, the second deformation index-depth sequence, and the energy index-depth sequence are constructed respectively. A moving calculation window is set from the deep part of the surrounding rock towards the tunnel wall on the constructed depth sequence. The moving calculation window covers multiple continuous monitoring points and moves towards the tunnel wall point by point along the monitoring path. At each position of the moving calculation window, the Pearson correlation coefficient (PCC) between the monitoring point depth as the independent variable and the index value corresponding to each monitoring point in the window as the dependent variable is calculated, so as to obtain the correlation coefficient-depth curve of the first deformation index, the correlation coefficient-depth curve of the second deformation index, and the correlation coefficient-depth curve of the energy index.

[0046] In one embodiment, the dependent variable is PVS when calculating the correlation coefficient of the first deformation index, PSS when calculating the correlation coefficient of the second deformation index, and VEDR when calculating the correlation coefficient of the energy index. The Pearson correlation coefficient is a well-known statistic used to characterize the linear correlation between index values ​​and depth.

[0047] In deep surrounding rock undisturbed by excavation, the indicators change relatively smoothly with depth, showing an approximately linear relationship with depth, and the Pearson correlation coefficient is close to 1. When the moving window enters the area affected by excavation, due to plastic deformation or damage evolution of the surrounding rock, the indicators change nonlinearly with depth, and the Pearson correlation coefficient decreases significantly.

[0048] Step 102 transforms the original index distribution into correlation change characteristics, providing a criterion basis for the subsequent identification of loosening zone boundaries and disturbance range boundaries.

[0049] Step 103: Identify abrupt change locations in the first deformation index correlation coefficient-depth curve and the second deformation index correlation coefficient-depth curve, and determine the boundary depth of the loosened zone based on their corresponding depths. .

[0050] In one exemplary instance, step 103 may include: The correlation coefficient-depth curve of the first deformation index and the correlation coefficient-depth curve of the second deformation index are traversed and calculated respectively. The point where the Pearson correlation coefficient changes at the largest rate along the depth direction is determined as the abrupt change position.

[0051] In one embodiment, the mutation location can be determined by calculating the difference in Pearson correlation coefficients between adjacent depth points. When the Pearson correlation coefficient shows a significant decrease and the decrease is a local maximum, the corresponding depth point is determined to be the mutation depth.

[0052] In one embodiment, the mutation depth corresponding to the first deformation index is denoted as... The mutation depth corresponding to the second deformation index is denoted as The depth of the loosened zone boundary is determined according to the following formula (1). : (1) In one embodiment, the first deformation index reflects the volume expansion failure characteristics of the surrounding rock, and the second deformation index reflects the shear slip failure characteristics of the surrounding rock. When the surrounding rock enters a loose and fractured state, the correlation between the two indices changes significantly. In this embodiment, the boundary of the loosened zone is determined by combining the abrupt change depth of the two indices, which reduces the randomness of single index determination and improves the stability of boundary identification.

[0053] Step 103 transforms the correlation change characteristics into the spatial location of the surrounding rock structural state transition, thereby obtaining the depth of the loosened zone boundary. .

[0054] Step 104: Identify abrupt change locations in the energy index correlation coefficient-depth curve and determine the corresponding depth as the boundary depth of the excavation disturbance influence range. .

[0055] In one exemplary instance, step 104 may include: The correlation coefficient-depth curve of the energy index was traversed and calculated to determine the point where the Pearson correlation coefficient changed at the maximum rate along the depth direction as the abrupt change location, and the corresponding depth was determined as the boundary depth of the excavation disturbance influence range. .

[0056] In one embodiment, the energy index is VEDR. When the surrounding rock is in an area undisturbed by excavation, the energy dissipation tends to be stable, and its Pearson correlation coefficient remains close to 1. When entering an area affected by excavation, the energy dissipation changes significantly, and the Pearson correlation coefficient decreases significantly, thus corresponding to the boundary of excavation disturbance.

[0057] Step 105: Determine the extent of the plastic zone based on the yielding state of the surrounding rock, and determine the depth of the loosened zone boundary. , depth of the plastic zone boundary Boundary of the excavation disturbance impact area If the preset physical constraints are met, output the result of the surrounding rock failure range determination; otherwise, return to step 100 until the preset physical constraints are met.

[0058] In one exemplary instance, the preset physical constraint condition may include: the loosening zone boundary depth. Less than the boundary depth of the plastic zone And the depth of the plastic zone boundary Less than the boundary of the excavation disturbance area ,Right now .

[0059] The method for determining the range of tunnel surrounding rock failure characteristics provided in this application accurately identifies the range of each failure characteristic, which has significant theoretical and engineering implications for tunnel stability evaluation, support structure design, and construction safety control. This application's method, based on a quantitative determination of surrounding rock failure characteristics using plastic strain and volumetric energy dissipation rate, defines the loosened zone through the Pearson correlation coefficient between plastic shear strain and volumetric strain; it uses the near-zero characteristic of the volumetric energy dissipation rate and its correlation coefficient to determine the boundary within the undisturbed zone, thereby accurately identifying the excavation influence range. The method for determining the range of tunnel surrounding rock failure characteristics provided in this application constructs a continuous and quantitative determination system from the loosened zone to the undisturbed zone, possessing a clear physical basis. It can reveal the spatiotemporal evolution law of the failure zone and provides a reliable basis for anchor bolt design, support optimization, and engineering stability assessment, combining theoretical innovation with engineering practicality.

[0060] This application also provides a computer-readable storage medium storing computer-executable instructions, which are used to execute the method for determining the range of tunnel surrounding rock damage characteristics as described in any of the above claims.

[0061] This application further provides a computer device, including a memory and a processor, wherein the memory stores the following instructions executable by the processor: steps for performing the method for determining the range of tunnel surrounding rock damage characteristics as described in any of the preceding claims.

[0062] The method for determining the range of tunnel surrounding rock failure characteristics provided in this application is a quantitative method based on a combination of plastic volumetric strain, plastic shear strain, and volumetric energy dissipation rate. It establishes a physically meaningful, spatially continuous, and logically self-consistent zoning system for surrounding rock failure characteristics, achieving complete identification from the loosened zone, plastic zone, to the undisturbed zone. Compared with traditional methods relying on a single strength criterion or empirical displacement threshold, this application not only determines whether the surrounding rock has entered a plastic state but also further distinguishes between the loosened zone, which has undergone structural relaxation and significant strength degradation, and the plastic zone, which still maintains residual bearing capacity. Simultaneously, it clearly defines the limit boundary of the excavation disturbance effect, thereby constructing a complete spatial sequence of surrounding rock failure and providing a systematic and quantitative analytical framework for surrounding rock stability evaluation.

[0063] In one embodiment, the present application significantly improves the accuracy and objectivity of determining the extent of surrounding rock failure. By performing statistical correlation analysis on the numerical simulation results, the traditional discrimination method relying on empirical thresholds or subjective observation curves is transformed into an objective identification process based on the changing characteristics of the Pearson correlation coefficient. The dual criteria of plastic volumetric strain and plastic shear strain characterize the rock mass degradation process from two mechanical dimensions: volume expansion and shear slip. Meanwhile, the judgment method based on the near-stability characteristics of volumetric energy dissipation rate identifies the propagation range of excavation disturbance from the perspective of energy evolution, giving the discrimination criteria strong physical connotation and engineering repeatability.

[0064] In one embodiment, this application further reveals the intrinsic relationship between excavation disturbance and energy dissipation in the surrounding rock, and reflects the spatiotemporal evolution of the damaged area. By employing a creep constitutive model based on internal variable thermodynamics theory for three-dimensional time-dependent numerical simulation, it achieves dynamic tracking of the strain and energy dissipation distribution of the surrounding rock over time after excavation, quantitatively describing the process of disturbance propagation from the cavern to the deeper rock mass and the differences in energy absorption and dissipation mechanisms in different regions, providing a theoretical basis for long-term stability analysis of the surrounding rock and optimization of support timing.

[0065] At the engineering application level, the discrimination results of the embodiments of this application can directly serve the optimization of support design. By accurately determining the depth of the loosening zone, the length of the anchor bolt can be reasonably determined to ensure that the anchoring section crosses the unstable area and enters the stable rock mass; by determining the boundary of the undisturbed zone, the influence range of the support structure can be assessed and the support parameters can be reasonably arranged, thereby realizing the transformation from experience-based design to quantitative design, which improves economy while ensuring engineering safety.

[0066] Furthermore, this application provides a closed-loop discrimination process with a logical consistency verification mechanism. By introducing the physical constraint relationship DL < DP < DU, the rationality of the discrimination results is verified, ensuring that the partitioning results maintain consistency in mechanical mechanism, thereby enhancing the applicability and robustness of the method in this application under complex geological conditions.

[0067] It should be noted that, theoretically, while using displacement or stress indices as a criterion is feasible—for example, analyzing the location of peak circumferential stress, abrupt changes in radial displacement gradient, or the extent of stress concentration zones to infer the failure area of ​​the surrounding rock—this has a certain theoretical basis within the framework of elastoplastic mechanics. However, such methods often struggle to distinguish the essential difference between rock mass undergoing only plastic yielding and rock mass undergoing structural relaxation and fracturing. Stress and displacement indices typically only reflect macroscopic mechanical responses and cannot directly characterize the internal structural degradation and energy dissipation mechanisms of the rock mass. More importantly, judgment methods based on displacement or stress thresholds usually rely on empirical parameters, such as displacement limits or stress concentration factors. These thresholds vary significantly with tunnel depth, size, surrounding rock strength, and geostress conditions, lacking a unified physical standard, leading to highly subjective and poorly repeatable judgment results. In contrast, the embodiments of this application introduce dual indices of plastic strain and energy dissipation rate, and employ statistical correlation to identify critical positions, establishing the judgment criteria based on physical evolution mechanisms, thus possessing better universality and stability.

[0068] Figure 3 This is a schematic diagram illustrating the range of surrounding rock damage characteristics induced by tunnel excavation in an embodiment of this application. Figure 3 This diagram illustrates the radial damage zoning structure of the surrounding rock after tunnel excavation, extending from the tunnel wall into the depths. Figure 3 As shown, the tunnel center is the cavity region with a radius of R; surrounding the cavity from the inside out are, in order, the loosened zone, the plastic zone, the elastic zone, and the undisturbed zone. The loosened zone is located near the tunnel wall, where the rock mass structure is clearly loose and fractured; its boundary depth is denoted as... The outer edge depth of the loosened zone within the plastic region is denoted as . The elastic zone is located outside the plastic zone, where the rock mass only undergoes an elastic response; the outermost zone is the undisturbed zone, and its inner boundary depth is denoted as... . Figure 3 The dashed circles represent the spatial boundaries of different zones, and the arrows indicate the direction of stress redistribution caused by excavation. This figure visually illustrates the three key boundaries to be identified in the embodiments of this application: loosening zone boundaries. Plastic zone boundary and the boundary of the excavation disturbance area .

[0069] Figure 4 This is a schematic diagram of the three-dimensional numerical simulation model of the tunnel in the embodiments of this application. Figure 4 A schematic diagram of a three-dimensional numerical simulation model for obtaining surrounding rock mechanical response data is shown, such as... Figure 4 As shown, the model is a cubic region with a tunnel structure in the middle. The distance between the model boundary and the center of the tunnel is no less than 3-5 times the tunnel diameter, so as to reduce the impact of boundary effects on the calculation results. Figure 4The left half of the diagram is a schematic diagram of the overall 3D model, showing the model's spatial dimensions (e.g., 100 m × 100 m × 100 m) and coordinate system orientation; Figure 4 The right half of the diagram is a schematic diagram of the densification of the grid around the cave. It can be seen that the grid is obviously densified near the cave wall and gradually becomes thicker towards the depth of the surrounding rock. Figure 4 This application demonstrates that the embodiments of this application use a spatially discretized three-dimensional time-dependent numerical simulation model to perform refined mechanical calculations on the surrounding rock, providing a data foundation for the subsequent extraction of indicators such as PVS, PSS, VEDR, and yield state.

[0070] Figure 5 This is a schematic diagram of the discrimination index and curve for the range of surrounding rock failure characteristics in the embodiments of this application. Figure 5 The diagram shows the schematic curves of three discriminant indices changing with depth and their corresponding Pearson correlation coefficients. Figure 5 The trends of PSS, PVS, and VEDR with depth, as well as the corresponding correlation coefficient changes, are presented from top to bottom. It can be seen that in the undisturbed area, the indicators change gradually and have an approximately linear relationship with depth, with a correlation coefficient close to 1; when entering the area affected by excavation, the indicators change non-linearly with depth, the correlation coefficient decreases significantly, and abrupt changes occur on the curve. Figure 5 The boundary of the loosening zone is marked. and the boundary of the undisturbed zone The corresponding position reflects the principle of this invention based on the identification boundary of correlation mutation.

[0071] Figure 6 This is a schematic diagram illustrating an example of determining the range of the loosening zone based on the plastic shear strain index in an embodiment of this application. Figure 6 The curves showing the variation of PSS and its corresponding Pearson correlation coefficient (PCC) with depth in the actual numerical calculation results are shown. Figure 6 In the graph, the horizontal axis represents the depth from the cave wall, the left vertical axis represents the PSS value, and the right vertical axis represents the PCC value. It can be seen that as depth increases, the PSS gradually decreases, while the PCC shows a significant jump at a certain depth, which corresponds to the depth of the loosened zone boundary. (Approximately 3.4 m in this example). This figure validates the effectiveness of identifying loose zone boundaries by analyzing PSS-related mutations.

[0072] Figure 7 This is a schematic diagram illustrating an example of determining the range of loosening zones based on the plastic volumetric strain index in this application. Figure 7 Numerical examples of PVS and its PCC variation with depth are shown. PVS gradually decreases with increasing depth, and the PCC curve changes significantly when the calculation window covers the loosening zone, corresponding to a depth of approximately 3.56 m. Figure 7As can be seen, the PVS index can also be used to identify the boundary of the loose zone. Combined with... Figure 6 Based on the PSS identification results, this embodiment of the application determines the final loosening zone boundary by averaging the two mutation depths. This improves the stability and accuracy of identification.

[0073] Figure 8 This is a schematic diagram illustrating an example of determining the boundary of the undisturbed region based on the volumetric energy dissipation rate index in an embodiment of this application. Figure 8 Example curves showing the variation of VEDR and its PCC with depth are presented. It can be seen that VEDR is relatively high near the tunnel wall and gradually approaches zero with increasing depth. When the calculation window is moved into the undisturbed zone, the PCC curve rises rapidly and then stabilizes. The abrupt change corresponds to a depth of approximately 4.45 m, which is identified as the boundary of the excavation disturbance influence range. . Figure 8 This embodies the principle of identifying the boundary within the undisturbed region from the perspective of energy dissipation.

[0074] Figure 9 This is a schematic diagram illustrating an example of the distribution of the plastic zone in the surrounding rock after tunnel excavation, as described in this application. Figure 9 The spatial distribution of the plastic zone in the surrounding rock after tunnel excavation, obtained from numerical simulation calculations, is shown, for example... Figure 9 The medium-dark shaded area represents the plastic zone in the yielding state, and its outer edge corresponds to the depth of the plastic zone boundary. (Approximately 3.60 m in this example). The plastic zone completely encloses the loosened zone and lies at the boundary of the undisturbed zone. Within, satisfy < < The physical constraints. Figure 9 This verifies the rationality and consistency of the spatial distribution of the partitioning results in the embodiments of this application.

[0075] Figure 10 This is a schematic diagram of the composition structure of the system for determining the range of tunnel surrounding rock failure characteristics in this application embodiment, as shown below. Figure 10 As shown, it includes at least: an acquisition module, a first determination module, a processing module, a second determination module, a third determination module, and a discrimination module; The acquisition module is used to acquire multiple sets of mechanical response data distributed along the depth direction of the surrounding rock of the tunnel. Each set of mechanical response data includes: a first deformation index for characterizing the degree of irreversible deformation of the rock mass volume, a second deformation index for characterizing the degree of irreversible deformation of the rock mass shear, and an energy index for characterizing the degree of energy dissipation due to damage to the surrounding rock. The mechanical response data are obtained from engineering calculations or monitoring and analysis results during the tunnel excavation process. The first determining module is used to determine the boundary depth of the plastic zone based on the distribution of the yield state of the surrounding rock along the depth direction in the mechanical response data. The processing module is used to establish data sequences of the first deformation index, the second deformation index, and the energy index as the surrounding rock depth changes, and to set a moving calculation window from the deep part of the surrounding rock towards the tunnel wall to calculate the Pearson correlation coefficient between the index value and the depth within the moving calculation window, thereby obtaining the correlation coefficient-depth curve of the first deformation index, the correlation coefficient-depth curve of the second deformation index, and the correlation coefficient-depth curve of the energy index. The second determining module is used to identify abrupt change locations in the first deformation index correlation coefficient-depth curve and the second deformation index correlation coefficient-depth curve, respectively, and determine the boundary depth of the loosened zone based on the corresponding depths of the two curves. ; The third determination module is used to identify abrupt change locations in the energy index correlation coefficient-depth curve and determine the corresponding depth as the boundary depth of the excavation disturbance influence range. ; The discrimination module is used to determine the extent of the plastic zone based on the yielding state of the surrounding rock and to determine the depth of the loosened zone boundary. , depth of the plastic zone boundary Boundary of the excavation disturbance impact area If the preset physical constraints are met, output the result of the surrounding rock failure range determination; otherwise, return to the processing of the acquisition module until the preset physical constraints are met.

[0076] The tunnel surrounding rock failure characteristic range identification system provided in this application accurately identifies the range of various failure characteristics of the surrounding rock, which has important theoretical and engineering significance for tunnel stability evaluation, support structure design, and construction safety control. This application's embodiment uses a quantitative discrimination method for surrounding rock failure characteristics based on plastic strain and volumetric energy dissipation rate. It defines the loosened zone using the Pearson correlation coefficient between plastic shear strain and volumetric strain; and uses the near-zero characteristic of volumetric energy dissipation rate and its correlation coefficient to determine the boundary within the undisturbed zone, thereby accurately identifying the excavation influence range. The tunnel surrounding rock failure characteristic range discrimination method provided in this application constructs a continuous and quantitative discrimination system from the loosened zone to the undisturbed zone, possessing a clear physical basis. It can reveal the spatiotemporal evolution law of the failure zone and provides a reliable basis for anchor bolt design, support optimization, and engineering stability assessment, combining theoretical innovation with engineering practicality.

[0077] Although the embodiments disclosed in this application are as described above, the content described is merely for the purpose of understanding this application and is not intended to limit this application. Any person skilled in the art to which this application pertains may make any modifications and changes in the form and details of the implementation without departing from the spirit and scope disclosed in this application; however, the scope of patent protection of this application shall still be determined by the scope defined in the appended claims.

Claims

1. A method for discriminating a range of tunnel surrounding rock failure characteristics, characterized by, include: Multiple sets of mechanical response data distributed along the depth direction of the surrounding rock of the tunnel are obtained. Each set of mechanical response data includes: a first deformation index for characterizing the degree of irreversible deformation of the rock mass volume, a second deformation index for characterizing the degree of irreversible deformation of the rock mass shear, and an energy index for characterizing the degree of energy dissipation due to damage to the surrounding rock. The mechanical response data are obtained from engineering calculations or monitoring and analysis results during the tunnel excavation process. Determining the plastic zone boundary depth according to the distribution of the surrounding rock yielding state along the depth direction in the mechanical response data ; Data sequences of the first deformation index, the second deformation index, and the energy index as a function of the surrounding rock depth were established. A moving calculation window was set from the deep part of the surrounding rock toward the tunnel wall. The Pearson correlation coefficient between the index values ​​and the depth within the moving calculation window was calculated to obtain the correlation coefficient-depth curve of the first deformation index, the correlation coefficient-depth curve of the second deformation index, and the correlation coefficient-depth curve of the energy index. The abrupt change positions are identified in the first deformation index correlation coefficient-depth curve and the second deformation index correlation coefficient-depth curve respectively, and the loose circle boundary depth is determined according to the corresponding depths of the two ; Identify the mutation position in the energy index correlation coefficient-depth curve, and determine the corresponding depth as the boundary depth of the excavation disturbance influence range ; Determine the plastic zone range based on the yield state of the surrounding rock, and determine the boundary depth of the loose circle , the boundary depth of the plastic zone and the boundary of the excavation disturbance influence range whether the preset physical constraint condition is met, if met, output the surrounding rock damage range determination result; if not met, return to step 100 until the preset physical constraint condition is met.

2. The discrimination method according to claim 1, wherein, The depth of the plastic zone boundary is determined based on the distribution of the surrounding rock yield state along the depth direction in the mechanical response data. ,include: Extract the surrounding rock yield state at each monitoring point along the selected observation path at the selected observation time. The monitoring path is traversed from the tunnel wall into the depth of the surrounding rock. When the depth corresponding to a monitoring point meets the preset yield condition, it is determined to be a plastic zone. The depth corresponding to the outermost position of all monitoring points in the yield state is determined as the boundary depth of the plastic zone. ; The surrounding rock yield state is used to characterize whether the surrounding rock has entered the stage of irreversible deformation. When the surrounding rock meets the preset yield criterion, the depth position of the monitoring point is in the surrounding rock yield state and is determined to be in the plastic zone. When the preset yield criterion is not met, it is determined to be in the elastic state.

3. The discrimination method according to claim 1, wherein, The process of obtaining the correlation coefficient-depth curve of the first deformation index, the correlation coefficient-depth curve of the second deformation index, and the correlation coefficient-depth curve of the energy index includes: Based on the values ​​of the first deformation index, the second deformation index, and the energy index at the corresponding depth positions of each monitoring point on the monitoring path, they are sorted in descending order of distance from the tunnel wall to construct the first deformation index-depth sequence, the second deformation index-depth sequence, and the energy index-depth sequence, respectively. The moving calculation window is set from the depth of the surrounding rock towards the tunnel wall on the constructed depth sequence. The moving calculation window covers multiple continuous monitoring points and moves towards the tunnel wall point by point along the monitoring path. At each position of the moving calculation window, the Pearson correlation coefficient PCC between the monitoring point depth as the independent variable and the index value corresponding to each monitoring point in the window as the dependent variable is calculated to obtain the first deformation index correlation coefficient-depth curve, the second deformation index correlation coefficient-depth curve and the energy index correlation coefficient-depth curve.

4. The discrimination method according to claim 3, wherein, When calculating the correlation coefficient of the first deformation index, the dependent variable is the plastic volumetric strain (PVS); when calculating the correlation coefficient of the second deformation index, the dependent variable is the plastic shear strain (PSS); and when calculating the correlation coefficient of the energy index, the dependent variable is the volumetric energy dissipation rate (VEDR).

5. The discrimination method according to claim 1, wherein, The locations of abrupt changes are identified in the first deformation index correlation coefficient-depth curve and the second deformation index correlation coefficient-depth curve, respectively, and the boundary depth of the loosening zone is determined based on the corresponding depths of the two curves. ,include: The correlation coefficient-depth curve of the first deformation index and the correlation coefficient-depth curve of the second deformation index are traversed and calculated respectively, and the point where the Pearson correlation coefficient changes at the largest rate along the depth direction is determined as the abrupt change position. The mutation depth corresponding to the first deformation index is denoted as The mutation depth corresponding to the second deformation index is denoted as The depth of the loosening zone boundary is determined according to the following formula. : .

6. The discrimination method according to claim 1, wherein, The process involves identifying abrupt change locations in the energy index correlation coefficient-depth curve and determining the corresponding depth as the boundary depth of the excavation disturbance influence range. ,include: The correlation coefficient-depth curve of the energy index is traversed and calculated to determine the point where the Pearson correlation coefficient changes at the largest rate along the depth direction as the abrupt change location, and the corresponding depth is determined as the boundary depth of the excavation disturbance influence range. .

7. The discrimination method according to claim 1, wherein, The preset physical constraints include: the depth of the loosening zone boundary. Less than the depth of the plastic zone boundary And the depth of the plastic zone boundary Smaller than the boundary of the excavation disturbance influence range : .

8. A computer-readable storage medium storing computer-executable instructions, said computer-executable instructions being used to execute the method for determining the range of tunnel surrounding rock damage characteristics as described in any one of claims 1-7.

9. A computer device comprising a memory and a processor, wherein, The memory stores the following instructions that can be executed by the processor: steps for performing the method for determining the range of tunnel surrounding rock damage characteristics as described in any one of claims 1-7.

10. A system for determining the range of damage characteristics of surrounding rock in tunnels, characterized in that, include: The module includes an acquisition module, a first determination module, a processing module, a second determination module, a third determination module, and a discrimination module. The acquisition module is used to acquire multiple sets of mechanical response data distributed along the depth direction of the surrounding rock of the tunnel. Each set of mechanical response data includes: a first deformation index for characterizing the degree of irreversible deformation of the rock mass volume, a second deformation index for characterizing the degree of irreversible deformation of the rock mass shear, and an energy index for characterizing the degree of energy dissipation due to damage to the surrounding rock. The mechanical response data are obtained from engineering calculations or monitoring and analysis results during the tunnel excavation process. The first determining module is used to determine the boundary depth of the plastic zone based on the distribution of the yield state of the surrounding rock along the depth direction in the mechanical response data. The processing module is used to establish data sequences of the first deformation index, the second deformation index, and the energy index as the surrounding rock depth changes, and to set a moving calculation window from the deep part of the surrounding rock towards the tunnel wall to calculate the Pearson correlation coefficient between the index value and the depth within the moving calculation window, thereby obtaining the correlation coefficient-depth curve of the first deformation index, the correlation coefficient-depth curve of the second deformation index, and the correlation coefficient-depth curve of the energy index. The second determining module is used to identify abrupt change locations in the first deformation index correlation coefficient-depth curve and the second deformation index correlation coefficient-depth curve, respectively, and determine the boundary depth of the loosened zone based on the corresponding depths of the two curves. ; The third determination module is used to identify abrupt change locations in the energy index correlation coefficient-depth curve and determine the corresponding depth as the boundary depth of the excavation disturbance influence range. ; The discrimination module is used to determine the extent of the plastic zone based on the yielding state of the surrounding rock and to determine the depth of the loosened zone boundary. , depth of the plastic zone boundary Boundary of the excavation disturbance impact area If the preset physical constraints are met, output the result of the surrounding rock failure range determination; otherwise, return to the processing of the acquisition module until the preset physical constraints are met.

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