Tunnel stress calculation method and system

Abstract

The present application relates to the technical field of tunnel ground stress calculation, in particular to a tunnel ground stress calculation method and system, comprising obtaining tunnel axis data, bank slope surface data, bank slope unloading influence zone boundary data, tunnel site area three-dimensional geological model and ground stress measured point data; dividing the ground stress measured point into background stress constraint points and unloading influence correction points; calculating background tectonic ground stress field and unloading influence correction parameters; determining unloading influence axis segment, calculating axis ground stress correction parameters; according to background ground stress data and axis ground stress correction parameters, calculating the tunnel ground stress of the unloading influence axis segment. The present application can reduce the interference of unloading influence measured points on background ground stress field calculation, and improve the accuracy of hard rock mountain tunnel ground stress calculation in deep gorge bank slope.

Description

Technical Field

[0001] This invention relates to the field of tunnel ground stress calculation technology, specifically a tunnel ground stress calculation method and system. Background Technology

[0002] The results of tunnel in-situ stress calculations are crucial for tunnel route layout, surrounding rock stability analysis, and construction risk assessment. Existing methods typically combine measured in-situ stress points, a three-dimensional geological model of the tunnel site, and boundary stress parameter inversion to calculate the in-situ stress distribution at the tunnel site.

[0003] However, for hard rock tunnels located on the slopes of deeply incised canyons, the tunnel axis may be in a transitional zone between the effects of slope unloading and the dominance of deep tectonic stress. Near-slope measurement points, affected by slope unloading, reflect a stress state that differs from the deep background stress state. Existing techniques often use measurement points of different origins as similar constraints in inversion, easily leading to interference from low-stress measurement points during unloading in the background stress field calculation. Furthermore, even when unloading-affected measurement points are identified, there is a lack of a computational mechanism to reasonably transfer local unloading stress deviations to the tunnel axis position, resulting in insufficient accuracy in calculating the stress values ​​and orientations of the unloading-affected axis segment. Summary of the Invention

[0004] The purpose of this invention is to provide a method and system for calculating tunnel geostress, in order to solve the problems in geostress calculation of hard rock tunnels in deep canyon slopes, where the background geostress field is easily affected by unloading and the measuring points are disturbed, and the local unloading stress deviation is difficult to reasonably transmit to the tunnel axis position.

[0005] To achieve the above objectives, on the one hand, the present invention provides a method for calculating tunnel in-situ stress, applicable to hard rock tunnels located within deeply incised canyon slopes, the method comprising: Step S1: Obtain tunnel axis data, bank slope surface data, bank slope unloading influence zone boundary data, three-dimensional geological model of the tunnel site area, and geostress measurement point data; based on the geostress measurement point data and bank slope unloading influence zone boundary data, divide the geostress measurement points into background stress constraint points and unloading influence correction points.

[0006] Step S2: Based on the background stress constraint points, perform boundary stress parameter inversion calculations on the three-dimensional geological model of the tunnel site area to obtain the background tectonic stress field.

[0007] Step S3: Calculate the unloading influence correction parameters based on the measured in-situ stress data of the unloading influence correction points and the background in-situ stress data of the corresponding measuring points in the background tectonic stress field; determine the unloading influence axis segment based on the tunnel axis data and the boundary data of the unloading influence zone on the bank slope; calculate the horizontal burial depth of the unloading influence correction points and the horizontal burial depth distribution of the unloading influence axis segment based on the bank slope surface data; calculate the axis in-situ stress correction parameters of the unloading influence axis segment based on the unloading influence correction parameters, the horizontal burial depth of the unloading influence correction points, and the horizontal burial depth distribution of the unloading influence axis segment.

[0008] Step S4: Calculate the tunnel stress in the unloading-affected axis segment based on the background geostress data and axis stress correction parameters in the background tectonic geostress field.

[0009] Furthermore, the method for dividing the measured ground stress points into background stress constraint points and unloading influence correction points based on the measured ground stress point data and the boundary data of the slope unloading influence zone includes: Ground stress measurement points whose spatial location is outside the spatial limit of the unloading influence zone boundary data in the ground stress measurement data are used as background stress constraint points, and ground stress measurement points whose spatial location is within the spatial limit of the unloading influence zone boundary data in the ground stress measurement data are used as unloading influence candidate points.

[0010] Based on the spatial location of each unloading influence candidate point, the corresponding local slope orientation is extracted from the slope data; the azimuth deflection angle between the measured maximum horizontal principal stress azimuth angle and the corresponding local slope orientation is calculated for each unloading influence candidate point, and the unloading influence candidate points whose azimuth deflection angle meets the preset unloading influence azimuth constraint conditions are used as unloading influence correction points.

[0011] Furthermore, the method for calculating the unloading influence correction parameters based on the measured in-situ stress data of the unloading influence correction point and the background in-situ stress data of the corresponding measuring point spatial location in the background tectonic in-situ stress field includes: Based on the spatial location of the measuring point of the unloading influence correction point, the maximum horizontal principal stress value and the azimuth of the maximum horizontal principal stress in the background are extracted from the background tectonic stress field to obtain the background stress data of the unloading influence correction point; the ratio of the measured maximum horizontal principal stress value of the unloading influence correction point to the maximum horizontal principal stress value in the background stress data of the unloading influence correction point is calculated to obtain the stress value correction coefficient.

[0012] Based on the measured maximum horizontal principal stress azimuth angle at the unloading influence correction point and the background maximum horizontal principal stress azimuth angle in the background geostress data at the unloading influence correction point, the stress azimuth correction angle is calculated; the stress value correction coefficient and the stress azimuth correction angle are determined as the unloading influence correction parameters.

[0013] Furthermore, the method for calculating the stress azimuth correction angle based on the measured maximum horizontal principal stress azimuth angle at the unloading influence correction point and the background maximum horizontal principal stress azimuth angle in the background geostress data at the unloading influence correction point includes: Based on the axial equivalent relationship of the direction of the maximum horizontal principal stress, the measured azimuth angle of the maximum horizontal principal stress and the background azimuth angle of the maximum horizontal principal stress are converted to the preset axial azimuth range to obtain the measured axial azimuth angle and the background axial azimuth angle; the minimum axial angle between the measured axial azimuth angle and the background axial azimuth angle is calculated to obtain the azimuth deflection amplitude.

[0014] The azimuth deflection direction is determined by rotating the background axial azimuth to the minimum axial rotation direction of the measured axial azimuth; the stress azimuth correction angle is generated based on the azimuth deflection amplitude and the azimuth deflection direction.

[0015] Furthermore, the method for calculating the axial stress correction parameters of the unloading influence axis segment based on the unloading influence correction parameters, the horizontal burial depth of the unloading influence correction point, and the horizontal burial depth distribution of the unloading influence axis segment includes: Based on the slope surface data, the boundary data of the slope unloading influence zone, and the horizontal burial depth of the unloading influence correction point, calculate the relative burial depth of the unloading influence corresponding to the unloading influence correction point; based on the slope surface data, the boundary data of the slope unloading influence zone, and the horizontal burial depth distribution of the unloading influence axis segment, calculate the relative burial depth distribution of the unloading influence axis segment.

[0016] Based on the distribution of the relative burial depth of the unloading influence on the axis segment and the relative burial depth of the unloading influence corresponding to the unloading influence correction point, the distribution of the migration difference of the correction parameters is calculated; based on the distribution of the migration difference of the correction parameters, the axis correction weight distribution of the unloading influence correction parameters in the unloading influence axis segment is determined.

[0017] The stress value correction coefficient of the axis is obtained by weighted calculation based on the axis correction weight distribution and the stress orientation correction angle in the unloading influence correction parameter; the stress orientation correction angle of the axis is obtained by weighted calculation based on the axis correction weight distribution and the unloading influence correction parameter.

[0018] The axial stress value correction coefficient and the axial stress orientation correction angle are determined as the axial ground stress correction parameters for the unloading-affected axial section.

[0019] Furthermore, the method for calculating the relative burial depth of the unloading influence corresponding to the unloading influence correction point based on the slope surface data, the boundary data of the unloading influence zone of the slope, and the horizontal burial depth of the unloading influence correction point includes: Based on the spatial location of the measuring point of the unloading influence correction point and the slope surface data, determine the horizontal entry direction of the measuring point that passes through the unloading influence correction point and is perpendicular to the local slope surface direction; along the horizontal entry direction of the measuring point, calculate the horizontal distance between the slope surface data and the boundary data of the unloading influence zone of the slope, and obtain the width of the local unloading influence zone corresponding to the unloading influence correction point.

[0020] Calculate the ratio of the horizontal burial depth of the unloading influence correction point to the width of the local unloading influence zone corresponding to the unloading influence correction point, and obtain the relative burial depth of the unloading influence corresponding to the unloading influence correction point.

[0021] Furthermore, the method for calculating the relative burial depth distribution of the unloading influence axis segment based on the slope surface data, the boundary data of the slope unloading influence zone, and the horizontal burial depth distribution of the unloading influence axis segment includes: Based on the spatial location of each axis position in the unloading influence axis segment and the slope surface data, determine the horizontal ingress direction of the axis position that passes through each axis position and is perpendicular to the direction of the corresponding local slope surface; along the horizontal ingress direction of the axis position, calculate the horizontal distance between the slope surface data and the boundary data of the unloading influence zone of the slope, and obtain the width distribution of the local unloading influence zone corresponding to the unloading influence axis segment.

[0022] The ratio of the horizontal burial depth distribution of the unloading influence axis segment to the width distribution of the local unloading influence zone corresponding to the unloading influence axis segment is calculated to obtain the relative burial depth distribution of the unloading influence of the unloading influence axis segment.

[0023] Furthermore, the method for calculating the tunnel in-situ stress of the unloading-affected axis segment based on the background in-situ stress data and axis stress correction parameters in the background tectonic stress field includes: Based on the spatial location of the unloading-affected axis segment, the background maximum horizontal principal stress value and the background maximum horizontal principal stress azimuth angle are extracted from the background tectonic stress field to obtain the background stress data of the unloading-affected axis segment.

[0024] Extract the axis stress value correction coefficient and axis stress azimuth correction angle from the axis stress correction parameters; calculate the product of the background maximum horizontal principal stress value and the axis stress value correction coefficient in the background stress data of the unloading-affected axis segment to obtain the maximum horizontal principal stress value of the unloading-affected axis segment.

[0025] According to the axial stress azimuth correction angle, the azimuth angle of the maximum horizontal principal stress in the background ground stress data of the unloading-affected axis segment is rotated to obtain the azimuth angle of the maximum horizontal principal stress of the unloading-affected axis segment; based on the maximum horizontal principal stress value and the azimuth angle of the maximum horizontal principal stress of the unloading-affected axis segment, the tunnel ground stress of the unloading-affected axis segment is obtained.

[0026] Based on the same inventive concept, this invention also provides a tunnel in-situ stress calculation system, the system comprising: The measuring point splitting module is used to acquire tunnel axis data, bank slope surface data, bank slope unloading influence zone boundary data, three-dimensional geological model of the tunnel site area, and geostress measurement point data. Based on the geostress measurement point data and bank slope unloading influence zone boundary data, the geostress measurement points are divided into background stress constraint points and unloading influence correction points.

[0027] The background inversion module is used to perform boundary stress parameter inversion calculations on the three-dimensional geological model of the tunnel site area based on the background stress constraint points, so as to obtain the background tectonic stress field.

[0028] The unloading migration module is used to calculate the unloading influence correction parameters based on the measured in-situ stress data of the unloading influence correction points and the background in-situ stress data of the corresponding measuring points in the background tectonic in-situ stress field; determine the unloading influence axis segment based on the tunnel axis data and the boundary data of the unloading influence zone on the bank slope; calculate the horizontal burial depth of the unloading influence correction points and the horizontal burial depth distribution of the unloading influence axis segment based on the bank slope surface data; and calculate the axis in-situ stress correction parameters of the unloading influence axis segment based on the unloading influence correction parameters, the horizontal burial depth of the unloading influence correction points, and the horizontal burial depth distribution of the unloading influence axis segment.

[0029] The in-situ stress calculation module is used to calculate the tunnel in-situ stress of the unloading-affected axis segment based on the background in-situ stress data and axis in-situ stress correction parameters in the background tectonic in-situ stress field.

[0030] Compared with the prior art, the beneficial effects of the present invention are: 1. Based on the boundary data of the slope unloading influence zone, the measured ground stress points are divided into background stress constraint points and unloading influence correction points. The background tectonic ground stress field is calculated using the background stress constraint points. Then, the unloading influence correction parameters are extracted based on the unloading influence correction points, and the background ground stress data of the unloading influence axis segment is corrected. This can reduce the interference of unloading influence measurement points on the calculation of the background ground stress field.

[0031] 2. Determine the horizontal ingress direction based on the local slope orientation, calculate the relative burial depth of the unloading influence zone based on the width of the local unloading influence zone, and determine the axis correction weight distribution based on the difference in the relative burial depth of the unloading influence zone. This enables the adaptive migration of the unloading influence correction parameters from discrete measured points to the unloading influence axis segment, which can reduce the impact of the unloading influence zone width variation at different slope locations on parameter transmission. Attached Figure Description

[0032] Figure 1 This is a flowchart of a tunnel ground stress calculation method according to the present invention; Figure 2 This is a block diagram of a tunnel ground stress calculation system according to the present invention. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] Example 1: As Figure 1 As shown, this embodiment provides a method for calculating tunnel in-situ stress, applied to hard rock tunnels located in deeply incised canyon slopes. The method includes: Acquire tunnel axis data, bank slope surface data, bank slope unloading influence zone boundary data, three-dimensional geological model of the tunnel site area, and geostress measurement point data; geostress measurement points whose spatial location is outside the spatial range defined by the bank slope unloading influence zone boundary data are used as background stress constraint points, and geostress measurement points whose spatial location is within the spatial range defined by the bank slope unloading influence zone boundary data are used as unloading influence candidate points.

[0035] Based on the spatial location of each unloading influence candidate point, the corresponding local slope orientation is extracted from the slope data; the azimuth deflection angle between the measured maximum horizontal principal stress azimuth angle and the corresponding local slope orientation is calculated for each unloading influence candidate point, and the unloading influence candidate points whose azimuth deflection angle meets the preset unloading influence azimuth constraint conditions are used as unloading influence correction points.

[0036] For example, the tunnel axis data is represented using the tunnel site engineering coordinate system. The X-axis is arranged along the tunnel's forward direction, the Y-axis is arranged along the horizontal incline direction perpendicular to the local slope surface within the tunnel's calculation corridor, and the Z-axis represents the elevation direction. The tunnel axis data consists of three-dimensional axis control points corresponding to station numbers K12+000, K12+200, K12+400, and K12+600, with coordinates of (0m, 520m, 1465m), (200m, 440m, 1462m), (400m, 360m, 1459m), and (600m, 500m, 1457m) respectively. The slope surface data was constructed using a triangular network of UAV laser point clouds and ground measurement points. The boundary data of the slope unloading influence zone was represented by a closed three-dimensional boundary surface determined by engineering geological mapping, borehole unloading fracture exposure, and geophysical interpretation results. Along the X=0m, X=200m, X=400m, and X=600m profiles, the horizontal influence widths corresponding to the slope unloading influence zone boundary data were 430m, 460m, 470m, and 450m, respectively. Continuous boundary surfaces were generated between adjacent profiles using linear interpolation. The three-dimensional geological model of the tunnel site area covered the spatial range of X=0m to 600m, Y=0m to 800m, and Z=1200m to 1700m. The measured ground stress data used were the results of hydraulic fracturing tests, including the spatial location of the measuring points, the measured maximum horizontal principal stress value, and the measured maximum horizontal principal stress azimuth angle.

[0037] The measured ground stress data were set into six sets: P1, P2, P3, P4, P5, and P6. The spatial location of the measuring point P1 was (120m, 520m, 1460m), with a measured maximum horizontal principal stress of 35.2 MPa and a measured maximum horizontal principal stress azimuth of 96°. The spatial location of the measuring point P2 was (480m, 565m, 1455m), with a measured maximum horizontal principal stress of 36.1 MPa and a measured maximum horizontal principal stress azimuth of 93°. The spatial location of the measuring point P3 was (90m, 125m, 1470m), with a measured maximum horizontal principal stress of 20.4 MPa and a measured maximum horizontal principal stress azimuth of 58°. The spatial location of measuring point P4 is (260m, 215m, 1462m), with a measured maximum horizontal principal stress of 24.8MPa and a measured maximum horizontal principal stress azimuth of 63°; the spatial location of measuring point P5 is (430m, 305m, 1458m), with a measured maximum horizontal principal stress of 27.6MPa and a measured maximum horizontal principal stress azimuth of 69°; the spatial location of measuring point P6 is (350m, 185m, 1460m), with a measured maximum horizontal principal stress of 25.1MPa and a measured maximum horizontal principal stress azimuth of 121°.

[0038] Points P1 and P2 are located outside the spatial limit defined by the boundary data of the slope unloading influence zone and are used as background stress constraint points. Points P3, P4, P5, and P6 are located within the spatial limit defined by the boundary data of the slope unloading influence zone and are used as candidate points for unloading influence. The slope triangular facets with the minimum horizontal distance to the candidate points for unloading influence are retrieved from the slope surface data. The orientation of the intersection line between the local tangent plane of the slope triangular facet and the horizontal plane is calculated to obtain the corresponding local slope orientation. In this embodiment, the local slope orientations corresponding to P3, P4, P5, and P6 are all 45°.

[0039] Azimuth deflection angle ;in, This indicates the azimuth angle of the measured maximum horizontal principal stress. Indicates the orientation of a local bank slope. When the angle exceeds 180°, the 180° value is taken first. The preset azimuth constraint condition for unloading influence is set as follows: the azimuth deflection angle is no greater than 30° (determined based on the statistical results of the azimuth deflection angle of the reference measuring points in the unloading fracture development zone of the tunnel site; the maximum azimuth deflection angle of the reference measuring points is 28.6°, rounded up to 30°). The azimuth deflection angle corresponding to P3 is 13°, the azimuth deflection angle corresponding to P4 is 18°, the azimuth deflection angle corresponding to P5 is 24°, and the azimuth deflection angle corresponding to P6 is 76°. Therefore, P3, P4, and P5 satisfy the preset azimuth constraint condition for unloading influence and are used as unloading influence correction points.

[0040] Based on the background stress constraint points, the boundary stress parameters of the three-dimensional geological model of the tunnel site area are inverted to obtain the background tectonic stress field. Based on the spatial location of the measurement points of the unloading influence correction points, the background maximum horizontal principal stress value and the background maximum horizontal principal stress azimuth are extracted from the background tectonic stress field to obtain the background stress data of the unloading influence correction points. The ratio of the measured maximum horizontal principal stress value of the unloading influence correction points to the background maximum horizontal principal stress value in the background stress data of the unloading influence correction points is calculated to obtain the stress value correction coefficient.

[0041] Based on the axial equivalent relationship of the direction of the maximum horizontal principal stress, the measured azimuth angle of the maximum horizontal principal stress and the background azimuth angle of the maximum horizontal principal stress are converted to the preset axial azimuth range to obtain the measured axial azimuth angle and the background axial azimuth angle; the minimum axial angle between the measured axial azimuth angle and the background axial azimuth angle is calculated to obtain the azimuth deflection amplitude.

[0042] The azimuth deflection direction is determined by rotating the background axial azimuth to the minimum axial rotation direction of the measured axial azimuth. The stress azimuth correction angle is then generated based on the azimuth deflection amplitude and direction. The stress value correction coefficient and the stress azimuth correction angle are determined as the unloading influence correction parameters.

[0043] The three-dimensional geological model of the tunnel site area was discretized using a tetrahedral finite element mesh. The rock mass was modeled using a linear elastic constitutive model, with an elastic modulus of 32 GPa, a Poisson's ratio of 0.24, and an average unit weight of 26.5 kN / m³. The slope surface was maintained as a free boundary, vertical displacement was constrained at the bottom of the model, and boundary stress parameters were applied to the side boundaries of the model. Boundary stress parameters were obtained using a boundary stress parameter set. It means that, among them, This represents the horizontal normal boundary stress along the X-axis direction. This represents the horizontal normal boundary stress along the Y-axis. This represents the horizontal shear stress in the XY plane.

[0044] Boundary stress parameter set according to 18MPa to 34MPa 24MPa to 42MPa The inversion search interval is established within the range of -8MPa to 8MPa, and the boundary stress parameter set is updated using the simplex optimization algorithm. After each boundary stress parameter set is loaded into the 3D geological model of the tunnel site, the calculated maximum horizontal principal stress value and the calculated maximum horizontal principal stress azimuth angle at the spatial locations of the corresponding measuring points P1 and P2 are extracted. The inversion matching error corresponding to the background stress constraint points is also considered. ;in, Indicates the first The calculated maximum horizontal principal stress value at each background stress constraint point Indicates the first The measured maximum horizontal principal stress value at each background stress constraint point. Indicates the first The minimum axial angle between the calculated maximum horizontal principal stress azimuth angle and the measured maximum horizontal principal stress azimuth angle at each background stress constraint point, converted according to the axial equivalence relationship. 15° is used as the normalization benchmark for the inversion error of the maximum horizontal principal stress azimuth angle at the background stress constraint point, used to convert the azimuth error into a dimensionless term and participate in the inversion matching error calculation. The inversion matching error decreases by less than [a certain value] for three consecutive iterations. Stop iterating when the time comes.

[0045] The boundary stress parameter set with the smallest inversion matching error is , , In the three-dimensional geological model of the tunnel site area after the boundary stress parameter set was applied, the calculated maximum horizontal principal stress at the spatial location of measuring point P1 was 35.0 MPa, and the calculated maximum horizontal principal stress azimuth angle was 95.5°; the calculated maximum horizontal principal stress at the spatial location of measuring point P2 was 36.3 MPa, and the calculated maximum horizontal principal stress azimuth angle was 93.6°. The measured maximum horizontal principal stress at P1 was 35.2 MPa, and the measured maximum horizontal principal stress azimuth angle was 96°; the measured maximum horizontal principal stress at P2 was 36.1 MPa, and the measured maximum horizontal principal stress azimuth angle was 93°. The boundary stress parameter set was used. , , The corresponding calculation results serve as the background tectonic stress field, which includes the stress distribution formed by the combined effects of the rock mass's self-weight stress and boundary stress parameters.

[0046] In the background tectonic stress field, the maximum horizontal principal stress at the measuring point P3 is 31.8 MPa, and the azimuth of the maximum horizontal principal stress is 92°; the maximum horizontal principal stress at the measuring point P4 is 33.0 MPa, and the azimuth of the maximum horizontal principal stress is 94°; the maximum horizontal principal stress at the measuring point P5 is 34.2 MPa, and the azimuth of the maximum horizontal principal stress is 95°. The maximum horizontal principal stress values ​​and azimuths of the maximum horizontal principal stress at P3, P4, and P5 constitute the background stress data at the unloading influence correction points.

[0047] The stress correction factor for P3 is 20.4 / 31.8=0.642, the stress correction factor for P4 is 24.8 / 33.0=0.752, and the stress correction factor for P5 is 27.6 / 34.2=0.807.

[0048] Preset axial orientation range The measured maximum horizontal principal stress azimuth angle of P3 is 58°, which is converted to obtain the measured axial azimuth angle of 58°. The background maximum horizontal principal stress azimuth angle of P3 is 92°, which is converted to obtain the background axial azimuth angle of 92°. The measured axial azimuth angle of P4 is 63°, and the background axial azimuth angle of P4 is 94°. The measured axial azimuth angle of P5 is 69°, and the background axial azimuth angle of P5 is 95°.

[0049] Azimuth deflection amplitude ;in, This indicates the measured axial azimuth angle. This indicates the azimuth angle of the background axis. The azimuth deflection amplitude of P3 is 34°, that of P4 is 31°, and that of P5 is 26°.

[0050] The minimum axial rotation direction from the background axial azimuth angle to the measured axial azimuth angle is recorded as clockwise (negative) and counterclockwise (positive). For P3, the minimum axial rotation direction from a background axial azimuth angle of 92° to a measured axial azimuth angle of 58° is clockwise, and the azimuth deflection direction of P3 is recorded as negative. For P4, the minimum axial rotation direction from a background axial azimuth angle of 94° to a measured axial azimuth angle of 63° is clockwise, and the azimuth deflection direction of P4 is recorded as negative. For P5, the minimum axial rotation direction from a background axial azimuth angle of 95° to a measured axial azimuth angle of 69° is clockwise, and the azimuth deflection direction of P5 is recorded as negative.

[0051] The stress orientation correction angle for P3 is -34°, for P4 it is -31°, and for P5 it is -26°. The stress value correction factor of P3 (0.642) and the stress orientation correction angle of -34° constitute the unloading influence correction parameter for P3; the stress value correction factor of P4 (0.752) and the stress orientation correction angle of -31° constitute the unloading influence correction parameter for P4; and the stress value correction factor of P5 (0.807) and the stress orientation correction angle of -26° constitute the unloading influence correction parameter for P5.

[0052] Based on the tunnel axis data and the boundary data of the unloading influence zone of the bank slope, the unloading influence axis segment is determined; based on the bank slope data, the horizontal burial depth of the unloading influence correction point and the horizontal burial depth distribution of the unloading influence axis segment are calculated.

[0053] The three-dimensional axis control points in the tunnel axis data are connected by lines to form a broken line axis. The outer edge of the horizontal projection of the bank slope data within the tunnel calculation corridor is fitted to the Y=0m baseline. The maximum fitting deviation between the outer edge of the horizontal projection of the bank slope data and the Y=0m baseline is 1.8m, which is lower than the spatial judgment error threshold of 2.0m corresponding to the spacing of the ground stress measurement points. The Y coordinate represents the horizontal distance from the bank slope surface to the interior of the mountain along the horizontal inward direction perpendicular to the local bank slope surface within the tunnel calculation corridor. The horizontal influence widths of the bank slope unloading influence zone boundary data at the X=0m, X=200m, X=400m, and X=600m profiles are 430m, 460m, 470m, and 450m, respectively. The continuous boundary between adjacent profiles is determined by linear interpolation.

[0054] In the section from K12+000 to K12+400, the Y-coordinate corresponding to the tunnel axis position decreases linearly from 520m to 360m, with a change rate of -0.4. In the section from K12+400 to K12+600, the Y-coordinate corresponding to the tunnel axis position increases linearly from 360m to 500m, with a change rate of 0.7. The spatial intersection of the broken-line axis with the boundary data of the slope unloading influence zone is determined. In the section from K12+000 to K12+200, when the Y-coordinate corresponding to the tunnel axis position is equal to the horizontal influence width corresponding to the boundary data of the slope unloading influence zone, an intersection point is formed that enters the spatial range defined by the boundary data of the slope unloading influence zone. The coordinates of the intersection point are (163.6m, 454.5m, 1462.5m). In the section from K12+400 to K12+600, when the Y-coordinate corresponding to the tunnel axis position is equal to the horizontal influence width corresponding to the boundary data of the slope unloading influence zone, an intersection point is formed that is outside the spatial range defined by the boundary data of the slope unloading influence zone. The coordinates of the intersection point are (537.5m, 456.3m, 1457.8m). The tunnel axis between the intersection point coordinates (163.6m, 454.5m, 1462.5m) and the intersection point coordinates (537.5m, 456.3m, 1457.8m) constitutes the unloading influence axis segment.

[0055] The spatial location of measuring point P3 is (90m, 125m, 1470m), and its horizontal burial depth is 125m; the spatial location of measuring point P4 is (260m, 215m, 1462m), and its horizontal burial depth is 215m; the spatial location of measuring point P5 is (430m, 305m, 1458m), and its horizontal burial depth is 305m. The horizontal burial depth of the unloading-affected axis segment within the X-coordinate range of 163.6m to 400m is... ;in, This represents the X-coordinate of the axis position within the unloading-affected axis segment. The intersection coordinates (163.6m, 454.5m, 1462.5m) correspond to a horizontal burial depth of 454.5m, and the three-dimensional axis control point (400m, 360m, 1459m) corresponds to a horizontal burial depth of 360m. The horizontal burial depth of the unloading-affected axis segment within the X-coordinate range of 400m to 537.5m... The horizontal burial depth corresponding to the three-dimensional axis control points (400m, 360m, 1459m) is 360m, and the horizontal burial depth corresponding to the intersection point coordinates (537.5m, 456.3m, 1457.8m) is 456.3m.

[0056] Based on the spatial location of the measuring point of the unloading influence correction point and the slope surface data, determine the horizontal entry direction of the measuring point that passes through the unloading influence correction point and is perpendicular to the local slope surface direction; along the horizontal entry direction of the measuring point, calculate the horizontal distance between the slope surface data and the boundary data of the unloading influence zone of the slope, and obtain the width of the local unloading influence zone corresponding to the unloading influence correction point.

[0057] Calculate the ratio of the horizontal burial depth of the unloading influence correction point to the width of the local unloading influence zone corresponding to the unloading influence correction point, and obtain the relative burial depth of the unloading influence corresponding to the unloading influence correction point.

[0058] Based on the spatial location of each axis position in the unloading influence axis segment and the slope surface data, determine the horizontal ingress direction of the axis position that passes through each axis position and is perpendicular to the direction of the corresponding local slope surface; along the horizontal ingress direction of the axis position, calculate the horizontal distance between the slope surface data and the boundary data of the unloading influence zone of the slope, and obtain the width distribution of the local unloading influence zone corresponding to the unloading influence axis segment.

[0059] The ratio of the horizontal burial depth distribution of the unloading influence axis segment to the width distribution of the local unloading influence zone corresponding to the unloading influence axis segment is calculated to obtain the relative burial depth distribution of the unloading influence of the unloading influence axis segment.

[0060] Based on the distribution of the relative burial depth of the unloading influence on the axis segment and the relative burial depth of the unloading influence corresponding to the unloading influence correction point, the distribution of the migration difference of the correction parameters is calculated; based on the distribution of the migration difference of the correction parameters, the axis correction weight distribution of the unloading influence correction parameters in the unloading influence axis segment is determined.

[0061] The stress value correction coefficient of the axis is obtained by weighted calculation based on the axis correction weight distribution and the stress orientation correction angle in the unloading influence correction parameter; the stress orientation correction angle of the axis is obtained by weighted calculation based on the axis correction weight distribution and the unloading influence correction parameter.

[0062] The axial stress value correction coefficient and the axial stress orientation correction angle are determined as the axial ground stress correction parameters for the unloading-affected axial section.

[0063] The slope orientation of the local bank slopes corresponding to points P3, P4, and P5 is all 45°. The horizontal entry direction of the measuring points passing through P3, P4, and P5 and perpendicular to the slope orientation is all 135°. The positive direction of the horizontal entry direction of the measuring points is taken as the direction from the bank slope surface towards the interior of the mountain. Along the horizontal entry direction of the measuring point corresponding to P3, the horizontal distance between the bank slope data and the boundary data of the bank slope unloading influence zone is 443.5m, and the width of the local unloading influence zone corresponding to P3 is 443.5m; along the horizontal entry direction of the measuring point corresponding to P4, the horizontal distance between the bank slope data and the boundary data of the bank slope unloading influence zone is 463.0m, and the width of the local unloading influence zone corresponding to P4 is 463.0m; along the horizontal entry direction of the measuring point corresponding to P5, the horizontal distance between the bank slope data and the boundary data of the bank slope unloading influence zone is 467.0m, and the width of the local unloading influence zone corresponding to P5 is 467.0m.

[0064] The unloading effect relative burial depth corresponding to the unloading effect correction point ;in, This indicates the horizontal burial depth of the correction point affected by unloading. This indicates the width of the local unloading influence zone corresponding to the unloading influence correction point. Substituting the values, the relative burial depth of the unloading influence corresponding to P3 is 125 / 443.5=0.282, the relative burial depth of the unloading influence corresponding to P4 is 215 / 463.0=0.464, and the relative burial depth of the unloading influence corresponding to P5 is 305 / 467.0=0.653.

[0065] The unloading-affected axis positions A1, A2, A3, A4, A5, and A6 are respectively taken as X=163.6m, X=200m, X=300m, X=400m, X=500m, and X=537.5m. The local slope orientation corresponding to A1, A2, A3, A4, A5, and A6 is all 45°. The horizontal inward slope direction of the axis positions passing through each axis position and perpendicular to the local slope orientation is all 135°. The positive direction of the horizontal inward slope direction of the axis positions is taken as the direction from the slope surface towards the interior of the mountain.

[0066] Along the horizontal slope direction corresponding to axis A1, the horizontal distance between the slope surface data and the boundary data of the slope unloading influence zone is 454.5m; along the horizontal slope direction corresponding to axis A2, the horizontal distance between the slope surface data and the boundary data of the slope unloading influence zone is 460.0m; along the horizontal slope direction corresponding to axis A3, the horizontal distance between the slope surface data and the boundary data of the slope unloading influence zone is 465.0m; along the horizontal slope direction corresponding to axis A4, the horizontal distance between the slope surface data and the boundary data of the slope unloading influence zone is 470.0m; along the horizontal slope direction corresponding to axis A5, the horizontal distance between the slope surface data and the boundary data of the slope unloading influence zone is 460.0m; along the horizontal slope direction corresponding to axis A6, the horizontal distance between the slope surface data and the boundary data of the slope unloading influence zone is 456.3m. The horizontal spacing between A1, A2, A3, A4, A5, and A6 constitutes the width distribution of the local unloading influence zone corresponding to the unloading influence axis segment.

[0067] The relative burial depth corresponding to the unloading influence of the centerline position in the unloading influence axis segment ;in, This indicates the horizontal burial depth corresponding to the position of the centerline of the axis segment affected by unloading. This indicates the width of the local unloading influence zone corresponding to the central axis position in the unloading influence axis segment. The relative burial depth of the unloading influence corresponding to A1 is 454.5 / 454.5=1.000, the relative burial depth of the unloading influence corresponding to A2 is 440.0 / 460.0=0.957, the relative burial depth of the unloading influence corresponding to A3 is 400.0 / 465.0=0.860, the relative burial depth of the unloading influence corresponding to A4 is 360.0 / 470.0=0.766, the relative burial depth of the unloading influence corresponding to A5 is 430.0 / 460.0=0.935, and the relative burial depth of the unloading influence corresponding to A6 is 456.3 / 456.3=1.000. A1 and A6 are located on the boundary surface of the unloading influence zone boundary data limited by the spatial range, and their horizontal burial depth is equal to the width of the local unloading influence zone, so the relative burial depth of the unloading influence is naturally calculated as 1.000.

[0068] The unloading affects the position of the center axis relative to the first axis segment. The difference in the migration of correction parameters at each unloading-affected correction point ;in, Indicates the first The unloading influence relative burial depth corresponds to each unloading influence correction point. Taking A4 as an example, the migration difference of the correction parameter of A4 relative to P3, P4 and P5 are |0.766-0.282|=0.484, |0.766-0.464|=0.302 and |0.766-0.653|=0.113, respectively.

[0069] The unloading influence correction parameters are continuously propagated along the relative burial depth difference of the unloading influence. The smaller the migration difference of the correction parameters, the greater the migration weight of the unloading influence correction parameters at the corresponding axis position. The axis position in the unloading influence axis segment corresponds to the first... The axis correction weight of each unloading-affected correction point ;in, This represents the relative burial depth migration attenuation scale; the adjacent differences in relative burial depth corresponding to the unloading influence correction point are 0.182 and 0.189, respectively, with an average value of 0.186. The relative burial depth migration attenuation scale is then rounded up. Set to 0.20. This indicates the proportion of the remaining unloading effect of the axis position relative to the boundary of the unloading influence zone on the slope in the unloading influence axis segment. When the relative burial depth of the unloading influence is 1.000, the axis correction weight is 0. The axis correction weights of A4 corresponding to P3, P4 and P5 are 0.024, 0.059 and 0.151, respectively. The axis correction weights for P3, P4, and P5 are 0.000, 0.000, and 0.000 for A1; 0.004, 0.011, and 0.028 for A2; 0.014, 0.035, and 0.090 for A3; 0.024, 0.059, and 0.151 for A4; 0.007, 0.016, and 0.042 for A5; and 0.000, 0.000, and 0.000 for A6.

[0070] Correction factor for axial stress value corresponding to the axial position in the unloading-affected axial section ;in, Indicates the first The stress value correction coefficients for each unloading influence correction point are as follows: The stress value correction coefficients for P3, P4, and P5 are 0.642, 0.752, and 0.807, respectively. The axial stress value correction coefficients for A1, A2, A3, A4, A5, and A6 are 1.000, 0.990, 0.969, 0.948, 0.985, and 1.000, respectively.

[0071] The axial stress orientation correction angle corresponding to the axial position in the unloading-affected axial segment ;in, Indicates the first The stress orientation correction angles of the unloading-affected correction points are as follows: P3, P4, and P5 have stress orientation correction angles of -34°, -31°, and -26°, respectively. The axial stress orientation correction angles corresponding to A1, A2, A3, A4, A5, and A6 are 0.0°, -1.2°, -3.9°, -6.6°, -1.8°, and 0.0°, respectively.

[0072] The axis stress correction parameters for A1 are: a stress value correction factor of 1.000 and an axis stress orientation correction angle of 0.0°. For A2, the axis stress correction parameters are: a stress value correction factor of 0.990 and an axis stress orientation correction angle of -1.2°. For A3, the axis stress correction parameters are: a stress value correction factor of 0.969 and an axis stress orientation correction angle of -3.9°. For A4, the axis stress correction parameters are: a stress value correction factor of 0.948 and an axis stress orientation correction angle of -6.6°. For A5, the axis stress correction parameters are: a stress value correction factor of 0.985 and an axis stress orientation correction angle of -1.8°. For A6, the axis stress correction parameters are: a stress value correction factor of 1.000 and an axis stress orientation correction angle of 0.0°.

[0073] Based on the spatial location of the unloading-affected axis segment, the background maximum horizontal principal stress value and the background maximum horizontal principal stress azimuth angle are extracted from the background tectonic stress field to obtain the background stress data of the unloading-affected axis segment.

[0074] Extract the axis stress value correction coefficient and axis stress azimuth correction angle from the axis stress correction parameters; calculate the product of the background maximum horizontal principal stress value and the axis stress value correction coefficient in the background stress data of the unloading-affected axis segment to obtain the maximum horizontal principal stress value of the unloading-affected axis segment.

[0075] According to the axial stress azimuth correction angle, the azimuth angle of the maximum horizontal principal stress in the background ground stress data of the unloading-affected axis segment is rotated to obtain the azimuth angle of the maximum horizontal principal stress of the unloading-affected axis segment; based on the maximum horizontal principal stress value and the azimuth angle of the maximum horizontal principal stress of the unloading-affected axis segment, the tunnel ground stress of the unloading-affected axis segment is obtained.

[0076] In the background tectonic stress field, the maximum horizontal principal stress values ​​at spatial locations A1 to A6 are 34.8 MPa, 34.5 MPa, 34.0 MPa, 33.6 MPa, 34.1 MPa, and 34.6 MPa, respectively, and the azimuth angles of the maximum horizontal principal stress at spatial locations A1 to A6 are 94.0°, 94.2°, 94.5°, 94.8°, 95.0°, and 95.1°, respectively. The maximum horizontal principal stress values ​​and azimuth angles at A1, A2, A3, A4, A5, and A6 constitute the background stress data for the unloading influence axis segment.

[0077] The maximum horizontal principal stress value of the unloading-affected axis segment corresponding to the centerline position of the unloading-affected axis segment. ;in, This represents the maximum horizontal principal stress value corresponding to the centerline position of the unloading-affected axis segment. Substituting these values ​​into the calculation, the maximum horizontal principal stress values ​​for the unloading-affected axis segments A1 to A6 are 34.8 MPa, 34.2 MPa, 32.9 MPa, 31.9 MPa, 33.6 MPa, and 34.6 MPa, respectively.

[0078] The azimuth angle of the maximum horizontal principal stress in the unloading-affected axis segment corresponding to the position of the axis in the unloading-affected axis segment. ;in, This represents the azimuth angle of the maximum horizontal principal stress in the background corresponding to the position of the central axis in the unloading-affected axis segment. In this embodiment, azimuth rotation is performed according to the axial stress azimuth correction angle, specifically by adding the azimuth angle of the maximum horizontal principal stress to the axial stress azimuth correction angle. The azimuth rotation result exceeds the preset axial azimuth range. At that time, after taking a 180° template, it was rewritten into the preset axial orientation range. Substituting into the calculation, the maximum horizontal principal stress azimuth angles of the unloading-affected axis segments corresponding to A1 to A6 were found to be 94.0°, 93.0°, 90.6°, 88.2°, 93.2°, and 95.1°, respectively.

[0079] The maximum horizontal principal stress of 34.8 MPa and the maximum horizontal principal stress azimuth of 94.0° in the unloading-affected axis segment corresponding to A1 constitute the tunnel ground stress corresponding to A1; the maximum horizontal principal stress of 34.2 MPa and the maximum horizontal principal stress azimuth of 93.0° in the unloading-affected axis segment corresponding to A2 constitute the tunnel ground stress corresponding to A2; the maximum horizontal principal stress of 32.9 MPa and the maximum horizontal principal stress azimuth of 90.6° in the unloading-affected axis segment corresponding to A3 constitute the tunnel ground stress corresponding to A3. The maximum horizontal principal stress of 31.9 MPa and the maximum horizontal principal stress azimuth angle of 88.2° in the unloading-affected axis segment corresponding to A4 constitute the tunnel ground stress corresponding to A4; the maximum horizontal principal stress of 33.6 MPa and the maximum horizontal principal stress azimuth angle of 93.2° in the unloading-affected axis segment corresponding to A5 constitute the tunnel ground stress corresponding to A5; the maximum horizontal principal stress of 34.6 MPa and the maximum horizontal principal stress azimuth angle of 95.1° in the unloading-affected axis segment corresponding to A6 constitute the tunnel ground stress corresponding to A6.

[0080] Example 2: Based on the same inventive concept, such as Figure 2 As shown, this embodiment also provides a tunnel ground stress calculation system, the system comprising: The measuring point splitting module is used to acquire tunnel axis data, bank slope surface data, bank slope unloading influence zone boundary data, three-dimensional geological model of the tunnel site area, and geostress measurement point data. Based on the geostress measurement point data and bank slope unloading influence zone boundary data, the geostress measurement points are divided into background stress constraint points and unloading influence correction points.

[0081] The background inversion module is used to perform boundary stress parameter inversion calculations on the three-dimensional geological model of the tunnel site area based on the background stress constraint points, so as to obtain the background tectonic stress field.

[0082] The unloading migration module is used to calculate the unloading influence correction parameters based on the measured in-situ stress data of the unloading influence correction points and the background in-situ stress data of the corresponding measuring points in the background tectonic in-situ stress field; determine the unloading influence axis segment based on the tunnel axis data and the boundary data of the unloading influence zone on the bank slope; calculate the horizontal burial depth of the unloading influence correction points and the horizontal burial depth distribution of the unloading influence axis segment based on the bank slope surface data; and calculate the axis in-situ stress correction parameters of the unloading influence axis segment based on the unloading influence correction parameters, the horizontal burial depth of the unloading influence correction points, and the horizontal burial depth distribution of the unloading influence axis segment.

[0083] The in-situ stress calculation module is used to calculate the tunnel in-situ stress of the unloading-affected axis segment based on the background in-situ stress data and axis in-situ stress correction parameters in the background tectonic in-situ stress field.

[0084] It should be noted that the specific methods by which each module performs operations in the system described in the above embodiments have been described in detail in the embodiments related to the method, and will not be elaborated here.

[0085] Finally, it should be noted that although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for calculating tunnel ground stress, characterized in that, The method, applicable to hard rock tunnels located on the slopes of deeply incised canyons, includes: Acquire tunnel axis data, bank slope surface data, bank slope unloading influence zone boundary data, three-dimensional geological model of the tunnel site area, and geostress measurement point data; based on the geostress measurement point data and bank slope unloading influence zone boundary data, divide the geostress measurement points into background stress constraint points and unloading influence correction points; Based on the background stress constraint points, the boundary stress parameters of the three-dimensional geological model of the tunnel site area are inverted to obtain the background tectonic stress field. Based on the measured in-situ stress data of the unloading influence correction point and the background in-situ stress data of the corresponding measuring point in the background tectonic in-situ stress field, calculate the unloading influence correction parameters; based on the tunnel axis data and the boundary data of the unloading influence zone of the bank slope, determine the unloading influence axis segment; based on the bank slope surface data, calculate the horizontal burial depth of the unloading influence correction point and the horizontal burial depth distribution of the unloading influence axis segment; based on the unloading influence correction parameters, the horizontal burial depth of the unloading influence correction point and the horizontal burial depth distribution of the unloading influence axis segment, calculate the axis in-situ stress correction parameters of the unloading influence axis segment. Based on the background geostress data and axis geostress correction parameters of the unloading-affected axis segment in the background tectonic geostress field, the tunnel geostress of the unloading-affected axis segment is calculated.

2. The method for calculating tunnel ground stress according to claim 1, characterized in that, The method for dividing the measured ground stress points into background stress constraint points and unloading influence correction points based on the measured ground stress point data and the boundary data of the slope unloading influence zone includes: Ground stress measurement points whose spatial location is outside the spatial limit of the unloading influence zone boundary data in the ground stress measurement point data are used as background stress constraint points, and ground stress measurement points whose spatial location is within the spatial limit of the unloading influence zone boundary data in the ground stress measurement point data are used as unloading influence candidate points. Based on the spatial location of each unloading influence candidate point, the corresponding local slope orientation is extracted from the slope data; the azimuth deflection angle between the measured maximum horizontal principal stress azimuth angle and the corresponding local slope orientation is calculated for each unloading influence candidate point, and the unloading influence candidate points whose azimuth deflection angle meets the preset unloading influence azimuth constraint conditions are used as unloading influence correction points.

3. The method for calculating tunnel ground stress according to claim 2, characterized in that, The method for calculating the unloading influence correction parameters based on the measured in-situ stress data of the unloading influence correction point and the background in-situ stress data of the corresponding measuring point spatial location in the background tectonic in-situ stress field includes: Based on the spatial location of the measuring point of the unloading influence correction point, the maximum horizontal principal stress value and the azimuth of the maximum horizontal principal stress in the background tectonic stress field are extracted to obtain the background stress data of the unloading influence correction point; the ratio of the measured maximum horizontal principal stress value of the unloading influence correction point to the maximum horizontal principal stress value in the background stress data of the unloading influence correction point is calculated to obtain the stress value correction coefficient. Based on the measured maximum horizontal principal stress azimuth angle at the unloading influence correction point and the background maximum horizontal principal stress azimuth angle in the background geostress data at the unloading influence correction point, the stress azimuth correction angle is calculated; the stress value correction coefficient and the stress azimuth correction angle are determined as the unloading influence correction parameters.

4. The method for calculating tunnel ground stress according to claim 3, characterized in that, The method for calculating the stress azimuth correction angle based on the measured maximum horizontal principal stress azimuth angle at the unloading influence correction point and the background maximum horizontal principal stress azimuth angle in the background geostress data at the unloading influence correction point includes: Based on the axial equivalent relationship of the direction of the maximum horizontal principal stress, the measured azimuth angle of the maximum horizontal principal stress and the background azimuth angle of the maximum horizontal principal stress are converted to the preset axial azimuth range to obtain the measured axial azimuth angle and the background axial azimuth angle; the minimum axial angle between the measured axial azimuth angle and the background axial azimuth angle is calculated to obtain the azimuth deflection amplitude. The azimuth deflection direction is determined by rotating the background axial azimuth to the minimum axial rotation direction of the measured axial azimuth; the stress azimuth correction angle is generated based on the azimuth deflection amplitude and the azimuth deflection direction.

5. The method for calculating tunnel ground stress according to claim 4, characterized in that, The method for calculating the axial stress correction parameters of the unloading influence axis segment based on the unloading influence correction parameters, the horizontal burial depth of the unloading influence correction point, and the horizontal burial depth distribution of the unloading influence axis segment includes: Based on the slope surface data, the boundary data of the slope unloading influence zone, and the horizontal burial depth of the unloading influence correction point, calculate the relative burial depth of the unloading influence corresponding to the unloading influence correction point; based on the slope surface data, the boundary data of the slope unloading influence zone, and the horizontal burial depth distribution of the unloading influence axis segment, calculate the relative burial depth distribution of the unloading influence axis segment. Based on the distribution of the relative burial depth of the unloading influence on the axis segment affected by unloading and the relative burial depth of the unloading influence corresponding to the unloading influence correction point, the distribution of the migration difference of the correction parameters is calculated; based on the distribution of the migration difference of the correction parameters, the axis correction weight distribution of the unloading influence correction parameters in the unloading influence axis segment is determined. The stress value correction coefficient of the axis is obtained by weighting the stress value correction coefficient in the axis correction weight distribution and the stress orientation correction angle in the unloading influence correction parameter; the stress orientation correction angle of the axis is obtained by weighting the stress value correction coefficient in the axis correction weight distribution and the unloading influence correction parameter. The axial stress value correction coefficient and the axial stress orientation correction angle are determined as the axial ground stress correction parameters for the unloading-affected axial section.

6. The method for calculating tunnel ground stress according to claim 5, characterized in that, The method for calculating the relative burial depth of the unloading influence corresponding to the unloading influence correction point based on the slope surface data, the boundary data of the unloading influence zone of the slope, and the horizontal burial depth of the unloading influence correction point includes: Based on the spatial location of the measuring point of the unloading influence correction point and the slope data of the bank slope, determine the horizontal entry direction of the measuring point that passes through the unloading influence correction point and is perpendicular to the local slope direction; along the horizontal entry direction of the measuring point, calculate the horizontal distance between the slope data of the bank slope and the boundary data of the unloading influence zone of the bank slope, and obtain the width of the local unloading influence zone corresponding to the unloading influence correction point. Calculate the ratio of the horizontal burial depth of the unloading influence correction point to the width of the local unloading influence zone corresponding to the unloading influence correction point, and obtain the relative burial depth of the unloading influence corresponding to the unloading influence correction point.

7. The method for calculating tunnel ground stress according to claim 5, characterized in that, The method for calculating the relative burial depth distribution of the unloading influence axis segment based on the slope surface data, the boundary data of the unloading influence zone of the slope, and the horizontal burial depth distribution of the unloading influence axis segment includes: Based on the spatial location of each axis position in the unloading influence axis segment and the slope surface data, determine the horizontal ingress direction of the axis position that passes through each axis position and is perpendicular to the direction of the corresponding local slope surface; along the horizontal ingress direction of the axis position, calculate the horizontal distance between the slope surface data and the boundary data of the unloading influence zone of the slope, and obtain the width distribution of the local unloading influence zone corresponding to the unloading influence axis segment. The ratio of the horizontal burial depth distribution of the unloading influence axis segment to the width distribution of the local unloading influence zone corresponding to the unloading influence axis segment is calculated to obtain the relative burial depth distribution of the unloading influence of the unloading influence axis segment.

8. The method for calculating tunnel ground stress according to claim 7, characterized in that, The method for calculating the tunnel stress in the unloading-affected axis segment based on the background geostress data and axis stress correction parameters in the background tectonic geostress field includes: Based on the spatial location of the unloading-affected axis segment, the background maximum horizontal principal stress value and the background maximum horizontal principal stress azimuth angle are extracted from the background tectonic stress field to obtain the background stress data of the unloading-affected axis segment. Extract the axis stress value correction coefficient and axis stress azimuth correction angle from the axis stress correction parameters; calculate the product of the background maximum horizontal principal stress value and the axis stress value correction coefficient in the background stress data of the unloading affected axis segment to obtain the maximum horizontal principal stress value of the unloading affected axis segment; According to the axial stress azimuth correction angle, the azimuth angle of the maximum horizontal principal stress in the background ground stress data of the unloading-affected axis segment is rotated to obtain the azimuth angle of the maximum horizontal principal stress of the unloading-affected axis segment; based on the maximum horizontal principal stress value and the azimuth angle of the maximum horizontal principal stress of the unloading-affected axis segment, the tunnel ground stress of the unloading-affected axis segment is obtained.

9. A tunnel ground stress calculation system, characterized in that, The system is used to perform the method according to any one of claims 1 to 8, the system comprising: The measuring point splitting module is used to acquire tunnel axis data, bank slope data, bank slope unloading influence zone boundary data, three-dimensional geological model of the tunnel site area, and geostress measurement point data; based on the geostress measurement point data and bank slope unloading influence zone boundary data, the geostress measurement points are divided into background stress constraint points and unloading influence correction points; The background inversion module is used to perform boundary stress parameter inversion calculations on the three-dimensional geological model of the tunnel site area based on the background stress constraint points, so as to obtain the background tectonic stress field. The unloading migration module is used to calculate the unloading influence correction parameters based on the measured in-situ stress data of the unloading influence correction points and the background in-situ stress data of the corresponding measuring points in the background tectonic in-situ stress field; determine the unloading influence axis segment based on the tunnel axis data and the boundary data of the unloading influence zone on the bank slope; calculate the horizontal burial depth of the unloading influence correction points and the horizontal burial depth distribution of the unloading influence axis segment based on the bank slope surface data; and calculate the axis in-situ stress correction parameters of the unloading influence axis segment based on the unloading influence correction parameters, the horizontal burial depth of the unloading influence correction points, and the horizontal burial depth distribution of the unloading influence axis segment. The in-situ stress calculation module is used to calculate the tunnel in-situ stress of the unloading-affected axis segment based on the background in-situ stress data and axis in-situ stress correction parameters in the background tectonic in-situ stress field.

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