Tunnel deformation prediction analysis platform based on crustal stress measurement

Abstract

The invention relates to the technical field of tunnel deformation, and discloses a tunnel deformation prediction analysis platform based on crustal stress measurement, which comprises a crustal stress measurement module, a crustal stress formation factor determination module, an initial crustal stress field inversion module, a three-dimensional tunnel model construction module and a deformation evolution characteristic analysis module, carrying out ground stress measurement on different drilling measuring points in the drilling area; a three-dimensional geologic model of the drilling area is constructed, and crustal stress forming factors of the drilling area are determined according to actually measured crustal stress parameters; calculating an initial crustal stress field of the three-dimensional geologic model by using a multiple regression equation; constructing a three-dimensional tunnel model of the target tunnel according to the boundary constraint condition, and performing initial ground stress balance calculation on the three-dimensional tunnel model by using the boundary constraint condition; and performing excavation simulation operation on the key section to obtain a model operation result, and analyzing deformation evolution characteristics of the key section according to the simulation operation result. The tunnel deformation prediction accuracy can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of tunnel deformation, and in particular to a tunnel deformation prediction and analysis platform based on ground stress measurement. Background Art

[0002] In recent years, with the substantial improvement of my country's economic strength and the rapid development of tunnel construction equipment technology and construction technology, the construction scale and advancement speed of my country's transportation tunnel projects have ranked first in the world. However, the surrounding rock stability and support structure safety issues of deep soft rock tunnels under complex geology and complex environments will become increasingly prominent. Therefore, it is necessary to predict tunnel deformation to ensure that the tunnel status can be grasped in a timely manner.

[0003] Existing tunnel deformation prediction and analysis technologies simply construct a tunnel model and use it to calculate numerical simulation results to predict tunnel deformation. In practical applications, the model building process requires consideration of the actual mechanical environment and factors that form geostress. Simply calculating a numerical model results in low accuracy in tunnel deformation prediction. Summary of the Invention

[0004] The present invention provides a tunnel deformation prediction and analysis platform based on ground stress measurement, the main purpose of which is to solve the problem of low accuracy in tunnel deformation prediction.

[0005] To achieve the purpose, the present invention provides a tunnel deformation prediction and analysis platform based on ground stress measurement, comprising:

[0006] A ground stress measurement module is used to obtain the drilling area of the target tunnel, measure the ground stress at different drilling points in the drilling area using a preset loop measurement strategy, and obtain measured ground stress parameters;

[0007] a geostress formation factor determination module, configured to construct a three-dimensional geological model of the drilling area based on the regional attributes of the drilling area, and determine the geostress formation factor of the drilling area according to the measured geostress parameters;

[0008] an initial geostress field inversion module, configured to calculate a multiple regression equation between stress values at different borehole measuring points and the measured stress values in the measured geostress parameters based on the geostress formation factors, and to calculate the initial geostress field of the three-dimensional geological model using the multiple regression equation;

[0009] a three-dimensional tunnel model construction module, configured to determine boundary constraints based on the initial geostress field, construct a three-dimensional tunnel model of the target tunnel based on the boundary constraints, and perform initial geostress balance calculation on the three-dimensional tunnel model using the boundary constraints;

[0010] The deformation evolution characteristic analysis module is used to extract the key sections of the three-dimensional tunnel model after calculating the ground stress balance, perform excavation simulation operations on the key sections, obtain model operation results, and analyze the deformation evolution characteristics of the key sections based on the simulation operation results.

[0011] Optionally, when the in-situ stress measurement module measures the in-situ stress at different drilling measurement points in the drilling area using a preset loop measurement strategy to obtain measured in-situ stress parameters, the in-situ stress measurement module is configured to:

[0012] selecting a target loop measurement strategy from the loop measurement strategies according to the area of different drilling measurement points in the drilling area;

[0013] performing plane processing on the drilling area using the target loop measurement strategy to obtain a plane stress model;

[0014] Calculate the stress of the target measuring point in the plane stress model according to the preset elastic mechanics:

[0015]

[0016] Among them, σ r is the radial stress at the target measuring point, σ θ is the tangential stress at the target measuring point, τ rθ is the shear stress of the target measuring point, r is the distance from the target measuring point to the center of the circular hole in the drilling area, σ1 is the first principal stress in the plane stress model, σ2 is the second principal stress in the plane stress model, θ is the angle between the target measuring point and the first principal stress, and α is the plane radius in the plane stress model;

[0017] Performing hydraulic pressure treatment on the drilled area, identifying the crack direction in the drilled area after the hydraulic pressure treatment, and determining the maximum horizontal principal stress direction at different drilled points according to the crack direction;

[0018] The measured ground stress parameters are determined according to the stress and the direction of the maximum horizontal principal stress.

[0019] Optionally, when constructing the three-dimensional geological model of the drilling area based on the regional attributes of the drilling area, the in-situ stress formation factor determination module is configured to:

[0020] determining a terrain surface range according to regional attributes of the drilling area, and constructing a natural terrain surface model of the drilling area according to the terrain surface range;

[0021] Using preset three-dimensional solid units to simulate the internal stratum structure corresponding to the natural terrain surface model, meshing the stratum structure, and applying mechanical property information to the meshed stratum structure;

[0022] A three-dimensional geological model of the drilling area is generated based on the stratigraphic structure with applied mechanical property information.

[0023] Optionally, when determining the geostress formation factor of the drilling area according to the measured geostress parameter, the geostress formation factor determination module is configured to:

[0024] Determining the magnitude and direction of the ground stress in the drilling area according to the measured ground stress parameters;

[0025] determining the extrusion characteristics of the target tunnel using the magnitude information and the direction information;

[0026] Determine the geomechanical characteristics of the target tunnel based on its geological structural characteristics, rock mechanical characteristics, and topographic and geomorphic characteristics, and determine the geological structural movement attributes based on the geomechanical characteristics;

[0027] The factors forming the ground stress are determined according to the compression characteristics and the geological tectonic movement attributes.

[0028] Optionally, when calculating a multiple regression equation between stress values at different borehole measuring points and measured stress values in the measured in-situ stress parameters according to the in-situ stress forming factors, the initial in-situ stress field inversion module is configured to:

[0029] Performing numerical simulation calculations on the borehole measuring points corresponding to each of the factors forming the ground stress, and obtaining stress values of each borehole measuring point under different factors;

[0030] Using the stress value as the independent variable data in the multiple regression equation and using the measured stress value in the measured ground stress parameter as the dependent variable data;

[0031] A multiple regression equation is generated based on the independent variable data and the dependent variable data, wherein the multiple regression equation is:

[0032]

[0033] in, is the measured stress value corresponding to the kth drilling point, L i The multiple regression coefficient corresponding to the i-th factor, is the stress value corresponding to the kth drilling point under the i-th factor, and n is the number of factors.

[0034] Optionally, when calculating the initial geostress field of the three-dimensional geological model using the multiple regression equation, the initial geostress field inversion module is used to:

[0035] The preset least squares method is used to calculate the minimum value of the residual sum of squares function, where the residual sum of squares function is:

[0036]

[0037] Among them, S c is the residual sum of squares, is the observed value of the jth stress component at the kth drilling point, L i The multiple regression coefficient corresponding to the i-th factor, is the stress value of the jth stress component at the kth drilling point under the i-th factor, n is the number of factors, and m is the number of drilling points;

[0038] determining a multiple regression coefficient in the multiple regression equation according to the minimum value;

[0039] Calculating the initial geostress of the three-dimensional geological model according to the multiple regression coefficients;

[0040] The initial geostress field of the three-dimensional geological model is constructed using the initial geostress.

[0041] Optionally, when determining boundary constraints according to the initial geostress field, the three-dimensional tunnel model construction module is configured to:

[0042] Extracting the principal stress tensors of the initial geostress field in a preset original coordinate system, and converting the principal stress tensors in the original coordinate system into stress tensors in a model coordinate system;

[0043] determining a maximum principal stress direction according to the stress tensor, and calculating a target stress according to an angle between a tunnel axis of a target tunnel and the maximum principal stress direction;

[0044] The target stress is used as a boundary constraint.

[0045] Optionally, when constructing the three-dimensional tunnel model of the target tunnel according to the boundary constraint condition, the three-dimensional tunnel model construction module is configured to:

[0046] Extracting the tunnel direction and tunnel size of the target tunnel, and constructing a tunnel framework model according to the tunnel direction and the tunnel size;

[0047] Configuring material parameters for the tunnel framework model according to material properties of the target tunnel;

[0048] Performing mixed unit grid division on the tunnel framework model after configuring material parameters, and encrypting the divided grid units toward the center of the tunnel framework model;

[0049] The boundary constraint conditions are applied to the encrypted tunnel framework model to obtain a three-dimensional tunnel model of the target tunnel.

[0050] Optionally, when performing excavation simulation calculation on the key section and obtaining the model calculation result, the deformation evolution characteristic analysis module is used to:

[0051] Determine the excavation method and excavation step length of the key section;

[0052] Performing excavation simulation calculation on the key section according to the excavation method and the excavation step;

[0053] After the excavation simulation is completed, the displacement parameters, stress parameters, and strain parameters corresponding to each excavation step in the key section are calculated;

[0054] A model calculation result is determined according to the displacement parameter, the stress parameter, and the strain parameter.

[0055] Optionally, when analyzing the deformation evolution characteristics of the key section according to the simulation operation results, the deformation evolution characteristic analysis module is configured to:

[0056] generating a displacement change curve, a stress change curve, and a strain change curve of the key section according to the simulation calculation results;

[0057] Determining the displacement change characteristics of the key section according to the displacement change curve, determining the stress change characteristics of the key section according to the stress change curve, and determining the strain change characteristics of the key section according to the strain change curve;

[0058] The deformation evolution characteristics of the key curve are determined according to the displacement change characteristics, the stress change characteristics, and the strain change characteristics.

[0059] The embodiment of the present invention obtains the drilling area of the target tunnel and uses the loop measurement strategy to measure the ground stress at different drilling points, so as to accurately obtain the measured ground stress parameters of the area; constructs a three-dimensional geological model based on the regional attributes of the drilling area, and determines the ground stress formation factors in combination with the measured ground stress parameters, which is conducive to a deep understanding of the ground stress formation mechanism of the geological environment in which the target tunnel is located; calculates the multiple regression equation between the stress values at different drilling points and the measured stress values based on the determined ground stress formation factors, and then uses the equation to calculate the initial ground stress field of the three-dimensional geological model, so that the measured data and the geological model can be used to obtain the ground stress field of the target tunnel. The combination of the three-dimensional model and the geostress model can more accurately invert the initial geostress field of the target area, making the simulation results closer to the actual situation; the boundary constraints are determined according to the initial geostress field, and then a three-dimensional tunnel model of the target tunnel is constructed, and the initial geostress balance calculation is performed to ensure that the tunnel model conforms to the actual geostress distribution in the initial state, providing a stable basic model that conforms to the actual geological conditions for subsequent excavation simulation; after calculating the geostress balance, the key sections of the three-dimensional tunnel model are subjected to excavation simulation operations, and their deformation evolution characteristics are analyzed, which can predict in advance the deformation trend and mechanical behavior of key parts of the tunnel during the excavation process. Therefore, the tunnel deformation prediction and analysis platform and method based on geostress measurement proposed in the present invention can solve the problem of low accuracy in tunnel deformation prediction. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1 This is a functional module diagram of a tunnel deformation prediction and analysis platform based on ground stress measurement provided by one embodiment of the present invention.

[0061] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0062] It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0063] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0064] The terms used in the embodiments of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The singular forms "a," "an," "the," and "the" used in the embodiments of the present invention and the appended claims are also intended to include plural forms, and unless the context clearly indicates otherwise, "a plurality" generally includes at least two.

[0065] As used herein, the words "if" and "if" may be interpreted as "at the time of" or "when" or "in response to determining" or "in response to detecting," depending on the context. Similarly, the phrases "if it is determined" or "if (stated condition or event) is detected" may be interpreted as "when it is determined" or "in response to the determination" or "when detecting (stated condition or event)" or "in response to detecting (stated condition or event)," depending on the context.

[0066] In addition, the step sequence in the following method embodiments is only an example and not a strict limitation.

[0067] In fact, the server-side device deployed by the tunnel deformation prediction and analysis platform based on ground stress measurement may be composed of one or more devices. The above-mentioned tunnel deformation prediction and analysis platform based on ground stress measurement can be implemented as: a business instance, a virtual machine, and a hardware device. For example, the tunnel deformation prediction and analysis platform based on ground stress measurement can be implemented as a business instance deployed on one or more devices in a cloud node. Simply put, the tunnel deformation prediction and analysis platform based on ground stress measurement can be understood as a software deployed on a cloud node, which is used to provide the tunnel deformation prediction and analysis platform based on ground stress measurement to each user terminal. Alternatively, the tunnel deformation prediction and analysis platform based on ground stress measurement can also be implemented as a virtual machine deployed on one or more devices in a cloud node. The virtual machine is installed with application software for managing each user terminal. Alternatively, the tunnel deformation prediction and analysis platform based on ground stress measurement can also be implemented as a server-side composed of many hardware devices of the same or different types, and one or more hardware devices are set up to provide the tunnel deformation prediction and analysis platform based on ground stress measurement to each user terminal.

[0068] In terms of implementation, the tunnel deformation prediction and analysis platform based on geostress measurement and the user end are mutually compatible. Specifically, if the tunnel deformation prediction and analysis platform based on geostress measurement is an application installed on a cloud service platform, the user end serves as a client that establishes a communication connection with the application. Alternatively, if the tunnel deformation prediction and analysis platform based on geostress measurement is implemented as a website, the user end is implemented as a webpage. Alternatively, if the tunnel deformation prediction and analysis platform based on geostress measurement is implemented as a cloud service platform, the user end is implemented as a mini-program within an instant messaging application.

[0069] Reference Figure 1, which is a functional module diagram of a tunnel deformation prediction and analysis platform based on ground stress measurement provided by one embodiment of the present invention.

[0070] The tunnel deformation prediction and analysis platform 100 based on ground stress measurement of the present invention can be set in a cloud server. In terms of implementation, it can be used as one or more service devices, or as an application installed on the cloud (such as a server of a mobile service operator, a server cluster, etc.), or it can also be developed as a website. According to the functions implemented, the tunnel deformation prediction and analysis platform 100 based on ground stress measurement can include a ground stress measurement module 101, a ground stress formation factor determination module 102, an initial ground stress field inversion module 103, a three-dimensional tunnel model construction module 104 and a deformation evolution feature analysis module 105. The module of the present invention can also be called a unit, which refers to a series of computer program segments that can be executed by a device processor and can complete fixed functions, which are stored in the memory of the device.

[0071] In an embodiment of the present invention, in the tunnel deformation prediction and analysis platform based on ground stress measurement, each of the above modules can be implemented independently and called with other modules. The call here can be understood as a module that can connect to multiple modules of another type and provide corresponding services to the multiple modules connected to it. For example, the sharing evaluation module can call the same information acquisition module to obtain the information collected by the information acquisition module. Based on the above characteristics, in the tunnel deformation prediction and analysis platform based on ground stress measurement provided by an embodiment of the present invention, the scope of application of the tunnel deformation prediction and analysis platform based on ground stress measurement can be adjusted by adding modules and directly calling them without modifying the program code, thereby realizing cluster-type horizontal expansion, so as to achieve the purpose of quickly and flexibly expanding the tunnel deformation prediction and analysis platform based on ground stress measurement. In actual applications, the above modules can be set in the same device or different devices, or they can be set in virtual devices, such as service instances in cloud servers.

[0072] The following describes the various components and specific workflows of the tunnel deformation prediction and analysis platform based on ground stress measurement in conjunction with specific embodiments.

[0073] The in-situ stress measurement module 101 is used to obtain a drilling area of a target tunnel, and perform in-situ stress measurement on different drilling measurement points in the drilling area using a preset loop measurement strategy to obtain measured in-situ stress parameters.

[0074] In an embodiment of the present invention, the drilling area refers to a specific area around the target tunnel or in a related geological body selected for purposes such as ground stress measurement, and positions for drilling are arranged within the area. Geological mapping, geophysical exploration, and other means can be used to conduct a detailed investigation of the geological structure, stratigraphic lithology, etc. of the area where the target tunnel is located to understand the distribution and changes of geological conditions, and preliminarily determine areas where the geological conditions are representative and convenient for drilling construction.

[0075] Furthermore, in order to more comprehensively reflect the distribution of ground stress in the drilling area, reduce measurement errors, and improve the accuracy and reliability of measurement results, it is necessary to obtain ground stress information from multiple angles and positions, so as to more accurately understand the stress state of different positions of the tunnel surrounding rock.

[0076] In an embodiment of the present invention, the loop measurement strategy includes single-loop measurement and dual-loop measurement. The single-loop system is suitable for measuring ground stress in small-diameter and deep boreholes, while the dual-loop system is suitable for measuring ground stress in large-diameter and shallow boreholes. The measured ground stress parameters refer to a set of parameters that can reflect the actual ground stress state in the drilling area, including the radial stress, tangential stress, and shear stress of the target measuring point calculated using elastic mechanics formulas, and the maximum horizontal principal stress direction determined through hydraulic processing.

[0077] In the embodiment of the present invention, when the in-situ stress measurement module 101 measures the in-situ stress at different drilling measurement points in the drilling area using a preset loop measurement strategy to obtain measured in-situ stress parameters, it is configured to:

[0078] selecting a target loop measurement strategy from the loop measurement strategies according to the area of different drilling measurement points in the drilling area;

[0079] performing plane processing on the drilling area using the target loop measurement strategy to obtain a plane stress model;

[0080] Calculate the stress of the target measuring point in the plane stress model according to the preset elastic mechanics:

[0081]

[0082] Among them, σ r is the radial stress at the target measuring point, σ θ is the tangential stress at the target measuring point, τ rθ is the shear stress of the target measuring point, r is the distance from the target measuring point to the center of the circular hole in the drilling area, σ1 is the first principal stress in the plane stress model, σ2 is the second principal stress in the plane stress model, θ is the angle between the target measuring point and the first principal stress, and α is the plane radius in the plane stress model;

[0083] Performing hydraulic pressure treatment on the drilled area, identifying the crack direction in the drilled area after the hydraulic pressure treatment, and determining the maximum horizontal principal stress direction at different drilled points according to the crack direction;

[0084] The measured ground stress parameters are determined according to the stress and the direction of the maximum horizontal principal stress.

[0085] In detail, different drilling area areas require different measurement strategies to ensure the accuracy and effectiveness of the measurement. Larger areas require more complex and comprehensive loops to cover in order to obtain sufficient measurement data; smaller areas can use relatively simple loops to avoid unnecessary waste of measurement points. By considering the area of the area, the measurement process is optimized, and the measurement efficiency and data quality are improved. Therefore, according to the area of the drilling area, the target loop measurement strategy is determined to be single-loop measurement or double-loop measurement, and the actual three-dimensional drilling area is simplified into a plane stress model. The infinite plate with a circular hole (radius α) has principal stresses σ1 and σ2, and the radial stress σ r The first part of the formula reflects the influence of the overall stress level on the radial stress, and the second part reflects the influence of the unevenness of the stress distribution on the radial stress; the tangential stress σ θ The first part before the minus sign represents the contribution of the average stress to the tangential stress, and the second part represents the effect of the stress difference on the tangential stress considering the distance and angle factors; the shear stress τ rθ The distribution of shear stress is described by terms related to distance and angle. The existence of shear stress affects the shear failure and deformation of rocks and is an important parameter for analyzing the mechanical behavior of rocks.

[0086] Specifically, hydraulic fracturing is a commonly used auxiliary method for geostress measurement. By injecting high-pressure liquid into the borehole, cracks are created in the rock surrounding the borehole. The theoretical basis for initial geostress measurement using hydraulic fracturing is elastic mechanics. This involves applying hydraulic pressure to the borehole, causing fractures in the wall. Geostress is then calculated based on parameters such as fracture pressure and instantaneous closure pressure. The selection of the test section must take into account the engineering design location and the integrity of the core rock, ensuring smooth borehole walls and consistent diameters. Before measurement, the drill pipe and fracturing device are leak-tested, numbered, and the instrument calibrated. Downhole measurement equipment is installed, and the numbered drill pipe is lowered to the desired location for the packer. The test section is sealed, and the packer is pressurized to ensure it adheres tightly to the borehole wall. Fracturing is performed, and the fracture pressure is recorded. The pump is shut down, and the instantaneous closure pressure is recorded. The pressure is then released. Each test section undergoes three to five cycles of testing. Finally, the fracture orientation is measured using the impression method to determine the maximum horizontal principal stress orientation. Since fractures tend to extend perpendicular to the direction of minimum principal stress, the maximum horizontal principal stress direction can be inferred by identifying the fracture orientation.

[0087] For example, by measuring the in-situ stress of the preset ZK-MYSSD-2 and ZK-MYSSD-3 boreholes, the principal stress values at different depths, the stress variation trend with depth, the principal stress magnitude relationship, the lateral pressure coefficient, and the maximum horizontal principal stress direction are obtained. For example, the maximum horizontal principal stress value in the measured range of the ZK-MYSSD-2 borehole is 7.67-9.36 MPa, and the minimum horizontal principal stress value is 5.87-8.08 MPa. The stress basically increases with depth, and the magnitude relationship of the three principal stresses is σ H >σ h >σ v , the maximum horizontal principal stress direction is N82°E, where σ H is the maximum horizontal principal stress, σ v is the vertical principal stress, σ h is the minimum horizontal principal stress, that is, when the hole is vertical, the maximum horizontal principal stress and the minimum horizontal principal stress are usually recorded as σ H and σ h , vertical principal stress σ v Equal to the weight of the overlying stratum, σ v =rh, r is the density of the rock; h is the thickness of the overlying rock.

[0088] Furthermore, the regional attributes of the drilling area contain rich geological information, such as rock type, stratigraphic distribution, geological structure, etc. In order to more clearly display the spatial morphology, mutual relationship and change law of the geological body, it is necessary to construct a finite element geological model of the drilling area.

[0089] The geostress formation factor determination module 102 is configured to construct a three-dimensional geological model of the drilling area based on the regional attributes of the drilling area, and determine the geostress formation factors of the drilling area according to the measured geostress parameters.

[0090] In the embodiment of the present invention, the three-dimensional geological model refers to a model constructed by computer technology that intuitively displays the morphology, structure, distribution and related physical and mechanical properties of a geological body in a three-dimensional space.

[0091] In an embodiment of the present invention, when constructing a three-dimensional geological model of the drilling area based on the regional attributes of the drilling area, the in-situ stress formation factor determination module 102 is configured to:

[0092] determining a terrain surface range according to regional attributes of the drilling area, and constructing a natural terrain surface model of the drilling area according to the terrain surface range;

[0093] Using preset three-dimensional solid units to simulate the internal stratum structure corresponding to the natural terrain surface model, meshing the stratum structure, and applying mechanical property information to the meshed stratum structure;

[0094] A three-dimensional geological model of the drilling area is generated based on the stratigraphic structure with applied mechanical property information.

[0095] Specifically, the regional attributes of the borehole area contain information about the terrain. This information can be used to determine the extent of the terrain surface, thereby clarifying the modeling boundaries and the general outline of the terrain. A natural terrain surface model is then constructed based on the determined scope. The natural terrain surface model is a preliminary simulation of the surface morphology of the borehole area. It depicts the undulations of the terrain and provides a basic surface framework for the subsequent construction of a complete three-dimensional geological model. The stratigraphic structure within the natural terrain surface model is then simulated using pre-set three-dimensional solid units. Three-dimensional solid units are basic units used for numerical simulation. They can be combined and arranged according to the actual conditions of the strata to accurately describe the distribution and morphology of different strata. This allows the underground stratigraphic structure to be presented in three dimensions, including the thickness of the different strata, the number of layers, and the relationships between them.

[0096] Specifically, the stratum structure is meshed and the continuous stratum structure is discretized into a finite number of units and nodes. Through meshing, numerical calculation and analysis can be performed more conveniently, because various physical quantities and boundary conditions can be defined on each unit and node, and mechanical property information is applied to the meshed stratum structure, including parameters such as the elastic modulus, Poisson's ratio, density, and strength of the rock, which determines the deformation, stress distribution, and destruction behavior of the stratum when subjected to external forces (such as ground stress, stress changes caused by tunnel excavation, etc.). In this way, the terrain surface model, the simulated and meshed stratum structure, and the applied mechanical property information are integrated to generate a three-dimensional geological model of the drilling area.

[0097] For example, the calculation range is determined according to the actual situation of Maoyu Mountain Tunnel, which is 7000m×1000m along the x-axis and y-axis, and from 100m below the design elevation of the tunnel axis to the natural terrain surface along the z-axis. The three-dimensional solid element solid45 is used to simulate the stratum, and the grid shape is selected according to the stratum conditions. The rock material mechanics calculation parameters are selected based on geological survey data and relevant specifications.

[0098] Furthermore, in order to intuitively analyze the impact mechanism of these structures on the ground stress in the drilling area through a three-dimensional geological model, it is necessary to more accurately determine the factors that form the ground stress. Based on the engineering geological survey report, a three-dimensional geological model of the calculation area was established using the finite element software ANSYS; based on the test results of the hydraulic fracturing method and combined with geomechanical analysis, the main factors affecting the formation of the initial ground stress field were determined.

[0099] In the embodiment of the present invention, the initial geostress field is mainly composed of the self-weight stress field and the tectonic stress field. Under normal circumstances, the following six geostress formation factors are used as basic factors to simulate the self-weight and tectonic force of the rock formation: self-weight stress state, east-west horizontal uniform compression tectonic movement, north-south horizontal uniform compression tectonic movement, uniform shear deformation tectonic movement in the horizontal plane, vertical uniform shear deformation tectonic movement in the east-west vertical plane, and vertical uniform shear deformation tectonic movement in the north-south vertical plane.

[0100] In an embodiment of the present invention, when determining the geostress formation factor of the drilling area according to the measured geostress parameters, the geostress formation factor determination module 102 is configured to:

[0101] Determining the magnitude and direction of the ground stress in the drilling area according to the measured ground stress parameters;

[0102] determining the extrusion characteristics of the target tunnel using the magnitude information and the direction information;

[0103] Determine the geomechanical characteristics of the target tunnel based on its geological structural characteristics, rock mechanical characteristics, and topographic and geomorphic characteristics, and determine the geological structural movement attributes based on the geomechanical characteristics;

[0104] The factors forming the ground stress are determined according to the compression characteristics and the geological tectonic movement attributes.

[0105] Specifically, the measured geostress parameters contain various detailed information about the geostress in the drilling area, thereby extracting the magnitude information (i.e., the size of the geostress) and direction information (the direction of action of the geostress). The obtained geostress magnitude information and direction information are used to analyze the extrusion conditions experienced by the target tunnel. For example, by judging the size and action mode of the geostress in different directions, it is determined whether the tunnel is subjected to obvious extrusion, as well as the main direction and intensity of the extrusion.

[0106] Specifically, by comprehensively considering the geological structural characteristics of the target tunnel (such as the distribution of folds and faults in the strata), the rock mechanical characteristics (such as the strength and elasticity of the rock), and the topographic and geomorphological characteristics (such as the undulations of the terrain and the direction of the mountains), we can fully understand the geomechanical environment in which the target tunnel is located. Based on these geomechanical characteristics, we can infer the properties of the geological tectonic movement, such as the type of geological tectonic movement (compression, tension, shear, etc.), the direction of movement, and the relative intensity. In addition, we can determine the factors that form ground stress by combining the compression characteristics of the target tunnel and the properties of the geological tectonic movement.

[0107] For example, given that there is no shear stress in the vertical plane in the measured ground stress results of the Maoyu Mountain Tunnel hydraulic fracturing method, only the following four basic factors are selected as basic factors to simulate the action of rock strata's own weight and tectonic force: self-weight stress state, compression tectonic movement along the x-axis, compression tectonic movement along the y-axis, and shear tectonic movement in the horizontal plane.

[0108] Furthermore, the factors that form geostress are complex and diverse. In order to make the stress field obtained by geological model inversion reasonable and credible, it is necessary to explain that the factors that form geostress under consideration can better explain the changes in the measured stress values.

[0109] The initial geostress field inversion module 103 is used to calculate a multiple regression equation between the stress values at different borehole measuring points and the measured stress values in the measured geostress parameters based on the geostress formation factors, and use the multiple regression equation to calculate the initial geostress field of the three-dimensional geological model.

[0110] In an embodiment of the present invention, the multiple regression equation is a statistical model used to describe the linear relationship between a dependent variable and multiple independent variables. By establishing a linear equation, the influence of multiple independent variables is combined to predict or explain the change of the dependent variable, that is, the change pattern of the measured stress value (dependent variable) in the measured ground stress parameter is explained by multiple ground stress forming factors (independent variables).

[0111] In the embodiment of the present invention, when calculating the multiple regression equation between the stress values at different borehole measuring points and the measured stress values in the measured in-situ stress parameters according to the in-situ stress formation factors, the initial in-situ stress field inversion module 103 is configured to:

[0112] Performing numerical simulation calculations on the borehole measuring points corresponding to each of the factors forming the ground stress, and obtaining stress values of each borehole measuring point under different factors;

[0113] Using the stress value as the independent variable data in the multiple regression equation and using the measured stress value in the measured ground stress parameter as the dependent variable data;

[0114] A multiple regression equation is generated based on the independent variable data and the dependent variable data, wherein the multiple regression equation is:

[0115]

[0116] in, is the measured stress value corresponding to the kth drilling point, L i The multiple regression coefficient corresponding to the i-th factor, is the stress value corresponding to the kth drilling point under the i-th factor, and n is the number of factors.

[0117] In detail, numerical simulation calculations are performed on the borehole measuring points corresponding to each of the factors forming the in-situ stress, and the stress value of each borehole measuring point under different factors is obtained. That is, by the numerical simulation method, based on the known factors forming the in-situ stress (such as the self-weight stress state, tectonic movements in various directions, etc.), for each borehole measuring point, the stress value borne by the measuring point under the action of each factor alone is calculated, thereby quantifying the influence of each factor on the stress of the borehole measuring point, providing data support for the subsequent establishment of a multiple regression equation, and based on the mathematical method of multiple regression, the regression calculation value of the initial in-situ stress is converted into the stress value of the borehole measuring point. Defined as the dependent variable, the numerical simulation results are etc. are defined as independent variables.

[0118] Specifically, a multiple regression equation is generated based on the independent variable data and the dependent variable data, and the multiple regression coefficient L i Indicates the effect of the i-th factor on the measured stress value The degree and direction of the influence of the independent variable data and dependent variable data The regression analysis shows that after considering the comprehensive effect of all n factors forming the ground stress, how to use their respective influence degrees L i To predict or explain measured stress values Then, a regression equation is constructed between the calculated stress value and the measured stress value at the ground stress measuring point under the unknown factors; the optimal solution of the coefficient of each unknown factor in the multivariate regression equation is obtained according to the principle of least squares method, and the initial ground stress field is obtained.

[0119] In the embodiment of the present invention, the initial geostress field refers to the spatial distribution of the stress state existing inside the rock mass in the three-dimensional geological model before being affected by subsequent engineering disturbances or other external factors, and describes the stress magnitude and direction at each position of the geological body in the initial state.

[0120] In the embodiment of the present invention, when calculating the initial geostress field of the three-dimensional geological model using the multiple regression equation, the initial geostress field inversion module 103 is used to:

[0121] The preset least squares method is used to calculate the minimum value of the residual sum of squares function, where the residual sum of squares function is:

[0122]

[0123] Among them, S c is the residual sum of squares, is the observed value of the jth stress component at the kth drilling point, L i The multiple regression coefficient corresponding to the i-th factor, is the stress value of the jth stress component at the kth drilling point under the i-th factor, n is the number of factors, and m is the number of drilling points;

[0124] determining a multiple regression coefficient in the multiple regression equation according to the minimum value;

[0125] Calculating the initial geostress of the three-dimensional geological model according to the multiple regression coefficients;

[0126] The initial geostress field of the three-dimensional geological model is constructed using the initial geostress.

[0127] In detail, the least squares method is a mathematical optimization technique that finds the best function matching the data by minimizing the sum of squared errors. i The value of S c Reach the minimum, so as to find the multiple regression coefficient that best fits the observed data. When the residual square sum function S c When it reaches the minimum value, the corresponding L i The value is the multiple regression coefficient to be solved, and n undetermined multiple regression coefficients L={L1,L2,…,L n}, and then substituted into the multiple regression equation, the regressed initial geostress of any point in the calculation area can be obtained, which can more accurately reflect the stress conditions of each point in the three-dimensional geological model, thereby obtaining the initial geostress of the three-dimensional geological model and expanding the discrete stress values to the space of the entire three-dimensional geological model to form a continuous stress field. The stress field describes the stress magnitude and direction of each position of the geological body in the initial state.

[0128] Specifically, four basic factors, namely, the self-weight stress state, the compression tectonic movement along the x-axis, the compression tectonic movement along the y-axis, and the shear tectonic movement in the horizontal plane, were selected as factors to simulate the self-weight and tectonic force of the rock strata, and corresponding boundary conditions were applied. A regression equation was established based on the multivariate regression mathematical method. The sum of squared residuals was minimized by the least squares method, and the regression coefficient was obtained to obtain the regression equation of the initial geostress field. By comparing the measured geostress values with the inversion regression calculated values, the error was basically controlled within 20%, indicating that the stress field obtained by inversion is reasonable and credible.

[0129] For example, numerical simulation was used to calculate the distribution of the geostress field under four different working conditions, and the stress cloud map under each working condition was extracted. The regression calculation value of the geostress at each borehole measuring point was obtained and converted into the principal stress value. The measured values of the geostress at the 100m, 200m, and 300m measuring points of two hydraulic fracturing boreholes were compared with the results of the inversion regression calculation values. It can be seen that the regression calculation value of the initial geostress is relatively close to the measured value, and the error is basically controlled within 20%. The change trends and overall laws of the two are the same, which shows that the stress field of the Maoyu Mountain Tunnel project area obtained by three-dimensional inversion regression is reasonable and credible.

[0130] Furthermore, based on the in-situ stress measurement, the in-situ stress inversion analysis was carried out, and the principal stress value showed a H >σ h >σ v According to the law, the maximum horizontal principal stress at the tunnel axis position is mostly between 16 and 20 MPa. The difference between the maximum horizontal principal stress and the minimum horizontal principal stress is large. There is a large shear stress in the tunnel plane, and the damage of the surrounding rock is usually caused by shear failure, which must be given sufficient attention.

[0131] Furthermore, the initial geostress field obtained based on the inversion can be used to analyze the changes in tunnel surrounding rock load and the excavation convergence deformation law.

[0132] The three-dimensional tunnel model construction module 104 is used to determine boundary constraints based on the initial geostress field, construct a three-dimensional tunnel model of the target tunnel based on the boundary constraints, and perform initial geostress balance calculation on the three-dimensional tunnel model using the boundary constraints.

[0133] In an embodiment of the present invention, the boundary constraint condition refers to a restriction imposed on the boundary of an object or system and is used to determine a unique solution to a problem. In a three-dimensional geological model, the boundary constraint condition is crucial for simulating the mechanical behavior of the geological body. Using the target stress as the boundary constraint condition means that when performing numerical simulation or other analysis on the three-dimensional geological model, the boundary of the model will be affected by this target stress.

[0134] In an embodiment of the present invention, when determining boundary constraints based on the initial geostress field, the three-dimensional tunnel model construction module 104 is configured to:

[0135] Extracting the principal stress tensors of the initial geostress field in a preset original coordinate system, and converting the principal stress tensors in the original coordinate system into stress tensors in a model coordinate system;

[0136] determining a maximum principal stress direction according to the stress tensor, and calculating a target stress according to an angle between a tunnel axis of a target tunnel and the maximum principal stress direction;

[0137] The target stress is used as a boundary constraint.

[0138] Specifically, stress is a second-order tensor that can be represented by a 3×3 matrix in three-dimensional space. The principal stress tensor refers to the diagonalized form of the stress tensor in a certain coordinate system. The elements on the diagonal are the principal stresses, representing the maximum and minimum normal stresses in a specific direction. For the initial geostress field, extracting the principal stress tensor in the preset original coordinate system is to determine the main characteristics of the geostress in that coordinate system, including the magnitude and direction of the principal stresses. Since the actual three-dimensional geological model may use a model coordinate system different from the original coordinate system, in order to accurately describe the geostress in the model, the principal stress tensor in the original coordinate system needs to be converted into the stress tensor in the model coordinate system.

[0139] Specifically, after obtaining the stress tensor in the model coordinate system, the direction of the maximum principal stress can be determined by analyzing the eigenvalues and eigenvectors of the stress tensor. The direction of the maximum principal stress is a key direction in the in-situ stress that affects the mechanical behavior of the rock mass, and determines the main deformation and failure trends that may occur in the rock mass when subjected to stress. The tunnel axis of the target tunnel is known. By calculating the angle between the tunnel axis and the direction of the maximum principal stress, the effect of the in-situ stress on the tunnel can be further analyzed, that is, boundary shift constraints are imposed on the three-dimensional model, and the initial stress is set according to the measured value of the in-situ stress. The principal stress tensor in the original coordinate system is converted into the stress tensor in the model coordinate system through the tensor conversion formula, and the stress on the model is calculated according to the angle between the tunnel axis and the direction of the maximum principal stress and substituted into the simulation as the boundary condition.

[0140] Furthermore, the target tunnel is located in a complex geological environment and is subject to the in-situ stresses of the surrounding rock mass. Boundary constraints can apply target stresses, determined based on the initial in-situ stress field, to the boundaries of the 3D tunnel model. This simulates the external forces experienced by the tunnel under actual geological conditions, enabling the model to more accurately reflect the tunnel's true stress state.

[0141] In the embodiment of the present invention, the three-dimensional tunnel model refers to a digital model in three-dimensional space constructed by computer finite element modeling technology, taking into account factors such as the tunnel's geometric shape, material properties, geological environment, and stress boundaries.

[0142] In an embodiment of the present invention, when constructing the three-dimensional tunnel model of the target tunnel according to the boundary constraint conditions, the three-dimensional tunnel model construction module 104 is configured to:

[0143] Extracting the tunnel direction and tunnel size of the target tunnel, and constructing a tunnel framework model according to the tunnel direction and the tunnel size;

[0144] Configuring material parameters for the tunnel framework model according to material properties of the target tunnel;

[0145] Performing mixed unit grid division on the tunnel framework model after configuring material parameters, and encrypting the divided grid units toward the center of the tunnel framework model;

[0146] The boundary constraint conditions are applied to the encrypted tunnel framework model to obtain a three-dimensional tunnel model of the target tunnel.

[0147] Specifically, the tunnel's orientation determines its spatial direction. For example, with the Y-axis as the tunnel's orientation, the tunnel face advances in the negative direction of the Y-axis. Tunnel dimensions include key parameters such as the tunnel's length, width, and height, clarifying the tunnel's geometric shape. Based on the acquired tunnel orientation and dimensions, a preliminary tunnel framework model is created in modeling software (such as MIDAS) to outline the tunnel's basic contours and spatial position. The target tunnel involves a variety of materials, such as surrounding rock materials (rocks of different grades) and support structure materials (anchors, shotcrete, steel arches, etc.). Each material has unique physical and mechanical properties, such as elastic modulus, Poisson's ratio, density, and strength. Based on geological survey reports and relevant design data, the specific properties of the materials of each part of the tunnel are determined, and these material parameters are accurately configured to the corresponding parts of the tunnel framework model, so that the model more realistically reflects the mechanical behavior of different materials under stress.

[0148] Specifically, a hybrid meshing method is used to mesh the tunnel framework model after configuring material parameters, and the mesh elements are then intensified toward the center of the tunnel framework model. The hybrid meshing method combines hexahedral and tetrahedral elements. Hexahedral elements have higher computational accuracy and are suitable for areas with regular shapes, while tetrahedral elements have better adaptability and can handle complex geometric shapes. By rationally combining these two elements, the model's adaptability to complex tunnel geometries can be improved while ensuring computational accuracy. Furthermore, the mesh elements are intensified toward the center of the tunnel framework model because the central area of the tunnel (such as the tunnel lining structure and the contact area between the surrounding rock and the support) experiences more dramatic stress and deformation changes when subjected to stress. Intensified meshing can more accurately capture these changes, improving the accuracy of the simulation results. Boundary constraints are accurately applied to the intensified tunnel framework model, enabling the model to simulate the stress conditions of the tunnel in an actual geological environment. After applying the boundary constraints, the model fully considers the tunnel's geometry, material properties, meshing, and actual stress boundaries, forming a three-dimensional tunnel model that accurately reflects the mechanical behavior of the target tunnel under actual working conditions.

[0149] For example, the MIDAS software was used to establish a tunnel model, with the Y-axis as the tunnel direction and the heading face advanced along the negative direction of the Y-axis. The model size was determined according to the Saint-Venant principle, and the grade IV and grade V surrounding rock sections of the Maoyu Mountain Tunnel were selected for simulation. Each layer of surrounding rock was regarded as a homogeneous material, and the grid was divided using hexahedron + tetrahedron mixed units and densified toward the center of the tunnel. The anchor rods were simulated using built-in anchor rod units, and the steel arch frame was simulated as a whole with the shotcrete using the equivalent modulus method. Three representative sections were selected, and the corresponding material parameters were selected according to the surrounding rock conditions and lining schemes of different sections.

[0150] In the embodiment of the present invention, when using MIDAS software to simulate tunnel excavation and support, in order to more realistically restore the distribution of ground stress in the actual engineering stratum and the state of stress redistribution after excavation disturbance, it is necessary to first perform an initial ground stress balance calculation after the model is established; after the calculation is completed, the displacement and velocity are reset to zero, and then the tunnel excavation simulation operation is performed.

[0151] Specifically, when constructing a three-dimensional tunnel model, after the model is established, its internal stress state may not match the actual initial geostress field. The initial geostress equilibrium calculation uses numerical calculation methods to allow the model's internal stress state to reach a relatively stable and balanced state before disturbances such as tunnel excavation are carried out, simulating the stress distribution of the actual geological body in its initial state. During the initial geostress equilibrium calculation, the elements in the model may produce certain displacements and velocities due to stress adjustments. However, these displacements and velocities are generated in the process of the model reaching the initial geostress equilibrium state, and are not caused by actual engineering activities such as tunnel excavation. Therefore, after the initial geostress equilibrium calculation is completed, the displacements and velocities of each element in the model need to be set to zero to eliminate these false displacements and velocities generated during the equilibrium calculation process, allowing the model to return to a true initial state and prepare for subsequent simulations of actual working conditions such as tunnel excavation, thereby truly reflecting the impact of engineering activities such as tunnel excavation on the model.

[0152] Furthermore, after completing the establishment of the 3D tunnel model and the initial geostress balance calculation (the initial geostress balance calculation is to ensure that the internal stress state of the model is consistent with the actual initial geostress field before it is disturbed by tunnel excavation), the model is in a relatively stable initial state. Since the entire tunnel model may contain long tunnel sections and complex geological conditions, in order to more specifically analyze key issues such as the mechanical response and stability of the tunnel, it is necessary to select representative parts, namely key sections, from the entire 3D tunnel model.

[0153] The deformation evolution characteristic analysis module 105 is used to extract the key sections of the three-dimensional tunnel model after calculating the ground stress balance, perform excavation simulation operations on the key sections, obtain model operation results, and analyze the deformation evolution characteristics of the key sections based on the simulation operation results.

[0154] In an embodiment of the present invention, the key sections include the vault, left and right arch haunches, left and right arch feet, and arch bottom of the tunnel. By extracting the key sections, we can focus on conducting in-depth analysis and research on these key areas, simulate the tunnel excavation process in the key sections, analyze the deformation and stress distribution of the surrounding rock, and evaluate the effectiveness of the support structure.

[0155] Furthermore, excavation simulation calculations are performed on key sections to analyze the stress state and deformation trend after excavation, thereby obtaining accurate excavation simulation calculation results.

[0156] In the embodiment of the present invention, the model calculation result refers to specific data on displacement parameters, stress parameters and strain parameters obtained by performing excavation simulation calculations on key sections.

[0157] In the embodiment of the present invention, when performing excavation simulation calculation on the key section and obtaining the model calculation result, the deformation evolution characteristic analysis module 105 is used to:

[0158] Determine the excavation method and excavation step length of the key section;

[0159] Performing excavation simulation calculation on the key section according to the excavation method and the excavation step;

[0160] After the excavation simulation is completed, the displacement parameters, stress parameters, and strain parameters corresponding to each excavation step in the key section are calculated;

[0161] A model calculation result is determined according to the displacement parameter, the stress parameter, and the strain parameter.

[0162] In detail, there are many excavation methods in tunnel engineering, such as full-section excavation method, step method (including two-step method, three-step method, etc.), circular excavation with reserved core soil method, CD method (center wall method), CRD method (cross center wall method), etc. Different excavation methods are suitable for different geological conditions and tunnel section sizes. To determine the excavation method for key sections, it is necessary to comprehensively consider factors such as the surrounding rock properties of the area (such as rock hardness and integrity, etc.), the burial depth of the tunnel, and the groundwater conditions. For example, for key sections with good surrounding rock stability, full-section excavation method may be used to improve construction efficiency; for sections with relatively weak surrounding rock, CRD method and other methods that emphasize step-by-step excavation and timely support may be used to control surrounding rock deformation; and excavation step Length refers to the advancing distance of each tunnel excavation. After determining the excavation method and excavation step of the key section, the excavation simulation of the key section is carried out using numerical simulation software (such as finite element software MIDAS, ANSYS, etc.). According to the selected excavation method, the tunnel excavation process is decomposed into multiple steps, and each step is advanced according to the excavation step. During the simulation process, the software will calculate the mechanical response of the surrounding rock and support structure after each excavation step based on pre-set material properties (such as elastic modulus and Poisson's ratio of the surrounding rock and support structure), boundary conditions (such as ground stress boundary, displacement boundary, etc.) and stress release caused by excavation, and simulate the deformation of the surrounding rock, stress redistribution and the stress condition of the support structure during tunnel excavation.

[0163] Specifically, the displacement parameters corresponding to each excavation step in the key section are calculated, including the displacement of the surrounding rock and support structure in all directions. The displacement parameters reflect the deformation of the surrounding rock and support structure after tunnel excavation; the stress distribution in the surrounding rock and support structure under each excavation step is determined, including normal stress and shear stress. The stress parameters can help understand the areas of stress concentration after tunnel excavation and the stress magnitude borne by the support structure; the strain parameters corresponding to each excavation step in the key section are calculated. The strain reflects the degree of deformation of the material.

[0164] Furthermore, typical sections were selected from various calculation models, and the simulation calculation results of each key point of the section (including the arch crown, left and right arch haunches, left and right arch feet, and arch base) were extracted to analyze the time-varying laws and evolution characteristics of the vertical displacement, horizontal displacement, principal stress of the surrounding rock along the tunnel, and the principal stress of the support structure as the excavation steps progressed.

[0165] In the embodiment of the present invention, the deformation evolution characteristics refer to a comprehensive description of the deformation development laws and characteristics of the key section from the initial state to the completion of excavation, taking into account the changes in displacement, stress and strain during the excavation process.

[0166] In the embodiment of the present invention, when analyzing the deformation evolution characteristics of the key section according to the simulation operation results, the deformation evolution characteristic analysis module 105 is configured to:

[0167] generating a displacement change curve, a stress change curve, and a strain change curve of the key section according to the simulation calculation results;

[0168] Determining the displacement change characteristics of the key section according to the displacement change curve, determining the stress change characteristics of the key section according to the stress change curve, and determining the strain change characteristics of the key section according to the strain change curve;

[0169] The deformation evolution characteristics of the key curve are determined according to the displacement change characteristics, the stress change characteristics, and the strain change characteristics.

[0170] In detail, the excavation step or time is used as the horizontal coordinate, and the specific values of displacement, stress and strain are used as the vertical coordinates. The data points are connected to obtain the corresponding change curves. For example, the displacement change curve can intuitively show how the displacement of different positions in the key section (such as the vault, side wall, etc.) changes as the excavation process progresses; the stress change curve can show the increase and decrease trend of stress during the excavation process and the stage of stress concentration; the strain change curve can reflect the degree of material deformation as the excavation progresses.

[0171] Specifically, observe the displacement change curve and analyze its slope, inflection point, maximum value and other characteristics. For example, the slope of the curve can reflect the rate of displacement growth. If the slope is large, it means that the displacement growth is fast, which may mean that the surrounding rock deformation is more severe. The inflection point may indicate that some special circumstances have occurred during the excavation process, such as encountering different geological conditions or nodes where support measures come into play. The maximum value can clearly identify the maximum displacement reached by the key section during the entire excavation process, which is very important for judging whether the tunnel will become unstable due to excessive displacement. From the stress change curve, identify whether the stress change trend is gradually increasing, decreasing or fluctuating, as well as the location and degree of stress concentration. If the stress is concentrated in certain parts, If the stress increases rapidly and exceeds the bearing capacity of the surrounding rock or support structure, it may cause damage; the stress fluctuation may be related to factors such as the excavation method and changes in geological conditions, so that the stress redistribution law during tunnel excavation can be determined, providing a basis for evaluating the stress state of the support structure; analyze the strain change curve to identify the development trend and variation range of the strain. The magnitude of the strain directly reflects the degree of deformation of the material. If the strain exceeds the limit strain of the material, the material may be damaged. At the same time, by observing the shape of the strain change curve, it can be judged whether the surrounding rock and support structure are in the elastic deformation stage or have entered the plastic deformation stage, and then the stability and safety of the tunnel can be evaluated.

[0172] For example, typical sections were selected from various calculation models, and simulation results for key points such as the arch crown, arch waist, arch foot, and arch base were extracted. The time-course variation and evolution characteristics of the vertical displacement, horizontal displacement, principal stress, and principal stress of the surrounding rock and support structure along the tunnel were analyzed as the excavation progressed. For example, in Section 1, the surrounding rock deformation caused by tunnel excavation was mainly characterized by arch crown settlement and arch base uplift. Affected by the lithology, the displacement value of the F5 fracture zone was significantly greater than that of the Tb slate joint-dense zone. The horizontal displacement of the surrounding rock was concentrated at the arch waists on both sides, showing an asymmetric distribution. The surrounding rock stress was affected by structural fractures and showed a significant asymmetric distribution. The maximum principal stress in most areas of the rock around the tunnel was mainly negative and compressive, but tensile principal stress failure zones appeared around the structural fractures and at the arch base along the tunnel.

[0173] The functional modules in various embodiments of the present invention may be integrated into a single processing unit, each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or hardware plus software functional modules.

[0174] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention.

[0175] Therefore, no matter from which point of view, the embodiments should be regarded as illustrative and non-restrictive, and the scope of the present invention is not limited only according to the above description, and it is intended that all changes within the meaning and scope of equivalent elements falling within the scope of protection are included in the present invention.

[0176] Furthermore, it is clear that the word "comprising" does not exclude other units or steps, and the singular does not exclude the plural. Multiple units or platforms recited in a platform claim may also be implemented by a single unit or platform through software or hardware. Terms such as "first" and "second" are used to indicate names and do not imply any particular order.

[0177] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A tunnel deformation prediction and analysis platform based on ground stress measurement, characterized by: The platform includes: A ground stress measurement module is used to obtain the drilling area of the target tunnel, measure the ground stress at different drilling points in the drilling area using a preset loop measurement strategy, and obtain measured ground stress parameters; a geostress formation factor determination module, configured to construct a three-dimensional geological model of the drilling area based on the regional attributes of the drilling area, and determine the geostress formation factor of the drilling area according to the measured geostress parameters; an initial geostress field inversion module, configured to calculate a multiple regression equation between stress values at different borehole measuring points and the measured stress values in the measured geostress parameters based on the geostress formation factors, and to calculate the initial geostress field of the three-dimensional geological model using the multiple regression equation; a three-dimensional tunnel model construction module, configured to determine boundary constraints based on the initial geostress field, construct a three-dimensional tunnel model of the target tunnel based on the boundary constraints, and perform initial geostress balance calculation on the three-dimensional tunnel model using the boundary constraints; The deformation evolution characteristic analysis module is used to extract the key sections of the three-dimensional tunnel model after calculating the ground stress balance, perform excavation simulation operations on the key sections, obtain model operation results, and analyze the deformation evolution characteristics of the key sections based on the simulation operation results.

2. The tunnel deformation prediction and analysis platform based on ground stress measurement according to claim 1, characterized in that: When the in-situ stress measurement module measures the in-situ stress at different drilling measurement points in the drilling area using a preset loop measurement strategy to obtain measured in-situ stress parameters, the module is used to: selecting a target loop measurement strategy from the loop measurement strategies according to the area of different drilling measurement points in the drilling area; performing plane processing on the drilling area using the target loop measurement strategy to obtain a plane stress model; Calculate the stress of the target measuring point in the plane stress model according to the preset elastic mechanics: Among them, σ r is the radial stress at the target measuring point, σ θ is the tangential stress at the target measuring point, τ rθ is the shear stress of the target measuring point, r is the distance from the target measuring point to the center of the circular hole in the drilling area, σ1 is the first principal stress in the plane stress model, σ2 is the second principal stress in the plane stress model, θ is the angle between the target measuring point and the first principal stress, and α is the plane radius in the plane stress model; Performing hydraulic pressure treatment on the drilled area, identifying the crack direction in the drilled area after the hydraulic pressure treatment, and determining the maximum horizontal principal stress direction at different drilled points according to the crack direction; The measured ground stress parameters are determined according to the stress and the direction of the maximum horizontal principal stress.

3. The tunnel deformation prediction and analysis platform based on ground stress measurement according to claim 1, characterized in that: The module for determining the geostress formation factors is used, when constructing a three-dimensional geological model of the drilling area based on the regional attributes of the drilling area, to: determining a terrain surface range according to regional attributes of the drilling area, and constructing a natural terrain surface model of the drilling area according to the terrain surface range; Using preset three-dimensional solid units to simulate the internal stratum structure corresponding to the natural terrain surface model, meshing the stratum structure, and applying mechanical property information to the meshed stratum structure; A three-dimensional geological model of the drilling area is generated based on the stratigraphic structure with applied mechanical property information.

4. The tunnel deformation prediction and analysis platform based on ground stress measurement according to claim 1, characterized in that: When determining the geostress formation factor of the drilling area according to the measured geostress parameter, the geostress formation factor determination module is used to: Determining the magnitude and direction of the ground stress in the drilling area according to the measured ground stress parameters; determining the extrusion characteristics of the target tunnel using the magnitude information and the direction information; Determine the geomechanical characteristics of the target tunnel based on its geological structural characteristics, rock mechanical characteristics, and topographic and geomorphic characteristics, and determine the geological structural movement attributes based on the geomechanical characteristics; The factors forming the ground stress are determined according to the compression characteristics and the geological tectonic movement attributes.

5. The tunnel deformation prediction and analysis platform based on ground stress measurement according to claim 1, characterized in that: The initial geostress field inversion module is used to calculate the multiple regression equation between the stress values at different borehole measuring points and the measured stress values in the measured geostress parameters according to the geostress formation factors: Performing numerical simulation calculations on the borehole measuring points corresponding to each of the factors forming the ground stress, and obtaining stress values of each borehole measuring point under different factors; Using the stress value as the independent variable data in the multiple regression equation and using the measured stress value in the measured ground stress parameter as the dependent variable data; A multiple regression equation is generated based on the independent variable data and the dependent variable data, wherein the multiple regression equation is: in, is the measured stress value corresponding to the kth drilling point, L i The multiple regression coefficient corresponding to the i-th factor, is the stress value corresponding to the kth drilling point under the i-th factor, and n is the number of factors.

6. The tunnel deformation prediction and analysis platform based on ground stress measurement according to claim 1, characterized in that: When calculating the initial geostress field of the three-dimensional geological model using the multiple regression equation, the initial geostress field inversion module is used to: The preset least squares method is used to calculate the minimum value of the residual sum of squares function, where the residual sum of squares function is: Among them, S c is the residual sum of squares, is the observed value of the jth stress component at the kth drilling point, L i The multiple regression coefficient corresponding to the i-th factor, is the stress value of the jth stress component at the kth drilling point under the i-th factor, n is the number of factors, and m is the number of drilling points; determining a multiple regression coefficient in the multiple regression equation according to the minimum value; Calculating the initial geostress of the three-dimensional geological model according to the multiple regression coefficients; The initial geostress field of the three-dimensional geological model is constructed using the initial geostress.

7. The tunnel deformation prediction and analysis platform based on ground stress measurement according to claim 1, characterized in that: When determining boundary constraints based on the initial geostress field, the three-dimensional tunnel model construction module is used to: Extracting the principal stress tensors of the initial geostress field in a preset original coordinate system, and converting the principal stress tensors in the original coordinate system into stress tensors in a model coordinate system; determining a maximum principal stress direction according to the stress tensor, and calculating a target stress according to an angle between a tunnel axis of a target tunnel and the maximum principal stress direction; The target stress is used as a boundary constraint.

8. The tunnel deformation prediction and analysis platform based on ground stress measurement according to claim 1, characterized in that: When constructing the three-dimensional tunnel model of the target tunnel according to the boundary constraint conditions, the three-dimensional tunnel model construction module is used to: Extracting the tunnel direction and tunnel size of the target tunnel, and constructing a tunnel framework model according to the tunnel direction and the tunnel size; Configuring material parameters for the tunnel framework model according to material properties of the target tunnel; Performing mixed unit grid division on the tunnel framework model after configuring material parameters, and encrypting the divided grid units toward the center of the tunnel framework model; The boundary constraint conditions are applied to the encrypted tunnel framework model to obtain a three-dimensional tunnel model of the target tunnel.

9. The tunnel deformation prediction and analysis platform based on ground stress measurement according to claim 1, characterized in that: When performing excavation simulation calculation on the key section and obtaining the model calculation results, the deformation evolution characteristic analysis module is used to: Determine the excavation method and excavation step length of the key section; Performing excavation simulation calculation on the key section according to the excavation method and the excavation step; After the excavation simulation is completed, the displacement parameters, stress parameters, and strain parameters corresponding to each excavation step in the key section are calculated; A model calculation result is determined according to the displacement parameter, the stress parameter, and the strain parameter.

10. The tunnel deformation prediction and analysis platform based on ground stress measurement according to claim 1, characterized in that: When analyzing the deformation evolution characteristics of the key section according to the simulation operation results, the deformation evolution characteristic analysis module is used to: generating a displacement change curve, a stress change curve, and a strain change curve of the key section according to the simulation calculation results; Determining the displacement change characteristics of the key section according to the displacement change curve, determining the stress change characteristics of the key section according to the stress change curve, and determining the strain change characteristics of the key section according to the strain change curve; The deformation evolution characteristics of the key curve are determined according to the displacement change characteristics, the stress change characteristics, and the strain change characteristics.

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