Tunnel Dynamic Design Method Based on the Deformation of Advanced Support

Abstract

The present invention discloses a tunnel dynamic design method based on the deformation of advanced support, which relates to the technical field of engineering data processing. A pre-trained particle swarm optimization algorithm is used to adjust the current support scheme; monitoring points are arranged during the construction process and monitoring data is collected in real time. An alarm value is constructed from the collected monitoring data. After determining the warning level based on the alarm value and the set alarm threshold, corresponding emergency response measures are taken; the loosening zone is dynamically adjusted in combination with the real-time monitoring data and continuously updated according to the construction process and monitoring data; the range of the loosening zone monitored in real time is compared with the initial design value to generate a deviation coefficient and determine whether it is necessary to adjust the support strength, including increasing support measures or dynamically optimizing the support parameters through a multi-objective optimization algorithm. By dynamically adjusting the support parameters, the deformation of the surrounding rock is effectively controlled, the risks caused by insufficient support are avoided, and the construction process is made more flexible and controllable.

Description

Technical Field

[0001] The present invention relates to the technical field of engineering data processing, and specifically to a tunnel dynamic design method based on the deformation of advanced support. Background Art

[0002] With the advancement of transportation infrastructure construction in western China, tunnel projects, especially those passing through soft surrounding rock, are increasing. Due to factors such as poor geological conditions, low strength of the surrounding rock, and untimely support in soft surrounding rock tunnels, they often face safety risks such as large deformations and collapses, seriously affecting the construction progress, quality, and surrounding environment. During tunnel construction, the deformation of the surrounding rock is one of the important factors affecting construction safety and economy. Although the existing New Austrian Tunneling Method has put forward the principles of "less disturbance, early support, frequent measurement, and tight closure", the surrounding rock monitoring mainly focuses on the settlement of the crown and the peripheral displacement in the excavated areas, ignoring the monitoring of the deformation of the advanced core soil in the surrounding rock in front of the heading face.

[0003] The construction of tunnel projects usually involves complex problems of surrounding rock and support design. During tunnel excavation, the stability of the surrounding rock directly affects the safety and construction progress of the project. The loosening zone of the surrounding rock (i.e., the area where the surrounding rock is damaged or deformed) is a key factor affecting tunnel safety and support design. To ensure the smooth progress of tunnel construction, engineers need to adjust the support plan according to the dynamic changes of the surrounding rock to deal with possible problems such as surrounding rock failure, displacement, and deformation. Traditional support design is usually based on empirical formulas or single numerical simulations, which are difficult to comprehensively and accurately reflect the actual situation of the surrounding rock. Therefore, combining various detection means and advanced numerical simulation techniques to achieve more accurate evaluation of the loosening zone and optimization of support design has become an urgent technical challenge in tunnel engineering.

[0004] In the Chinese invention patent with the authorization announcement number CN114329701B, a support design method for large-deformation tunnels with a buffer layer is provided. Considering the yielding pressure, yielding amount, and energy absorption characteristics, it proposes a specific structural scheme for the buffer layer support of large-deformation tunnels, providing accurate and effective data support for the support design of the buffer layer of deformed tunnels. The method includes: obtaining the ultimate bearing capacity of the secondary lining structure corresponding to the target buffer layer support of the large-deformation tunnel; screening out the second candidate filling material whose yielding stage termination stress is less than the ultimate bearing capacity of the secondary lining structure; screening out the target candidate filling material with the maximum sum of the energy absorption in the elastic stage and the energy absorption in the yielding stage as the filling material for the target buffer layer support of the large-deformation tunnel; obtaining the required yielding deformation amount of the target buffer layer support of the large-deformation tunnel; and determining the thickness of the target buffer layer support of the large-deformation tunnel according to the required yielding deformation amount and the yielding stage termination strain of the target candidate filling material.

[0005] The existing tunnel excavation support design methods have significant limitations, mainly reflected in two aspects. First, the traditional loose circle estimation method relies on empirical formulas, which can provide preliminary design references but are difficult to accurately consider the dynamic changes of surrounding rocks during actual construction, resulting in insufficient accuracy of the support plan. Second, the existing support design adjustment methods mainly rely on manual judgment and manual optimization, with low efficiency and lack of a real-time feedback mechanism, and cannot adjust the support design in a timely manner according to the construction progress.

[0006] Therefore, the present invention provides a tunnel dynamic design method based on the deformation of advanced support. Summary of the Invention

[0007] (I) Technical problems to be solved

[0008] Aiming at the deficiencies of the existing technology, the present invention provides a tunnel dynamic design method based on the deformation of advanced support. By using a pre-trained particle swarm optimization algorithm to adjust the current support plan; during the construction process, monitoring points are arranged and monitoring data is collected in real time, a warning value is constructed from the collected monitoring data, and after determining the warning level based on the warning value and the set warning threshold, corresponding emergency response measures are taken; the loose circle is dynamically adjusted in combination with the real-time monitoring data and continuously updated according to the construction process and monitoring data; the range of the loose circle monitored in real time is compared with the initial design value, a deviation coefficient is generated and it is judged whether the support strength needs to be adjusted, including increasing support measures or dynamically optimizing support parameters through a multi-objective optimization algorithm. By dynamically adjusting the support parameters, the deformation of the surrounding rock can be effectively controlled, the risks caused by insufficient support can be avoided, and the construction process can be made more flexible and controllable. A dynamic loose circle evaluation method based on multiple monitoring technologies and three-dimensional numerical simulation, combined with a particle swarm optimization algorithm to optimize the support plan, so as to realize the real-time matching of the dynamic changes of the surrounding rock and the support design, and optimize the safety and economy of the support.

[0009] (II) Technical solutions

[0010] To achieve the above objectives, the present invention is realized through the following technical solutions: A tunnel dynamic design method based on the deformation of advanced support, including using a variety of detection methods to collect geological detection data of the surrounding rock, initially estimating the range of the loose circle in combination with empirical formulas, analyzing the deformation of the surrounding rock during the excavation process through three-dimensional numerical simulation, and outputting a two-dimensional cross-sectional view or a three-dimensional spatial distribution map of the initial surrounding rock loose circle;

[0011] After matching the corresponding support plan according to the estimated range of the loose circle, using a pre-trained particle swarm optimization algorithm to adjust the current support plan with the surrounding rock displacement control value as the optimization constraint condition and construction safety and economy as the optimization objectives;

[0012] During the construction process, monitoring points are arranged and monitoring data is collected in real time, and a warning value V is constructed from the collected monitoring datafinal , according to the warning value V final After determining the warning level based on the set warning threshold, corresponding emergency response measures are taken;

[0013] The loose circle is dynamically adjusted in combination with real-time monitoring data. Based on the adjusted loose circle range, the inversion model is used to calculate the dynamic loose circle distribution of the surrounding rock, and the two-dimensional profile distribution map or three-dimensional model of the loose circle is drawn and continuously updated according to the construction process and monitoring data;

[0014] Compare the range of the loose circle monitored in real time with the initial design value to generate the deviation coefficient D total And judge whether it is necessary to adjust the support strength, including increasing support measures or dynamically optimizing support parameters through a multi-objective optimization algorithm.

[0015] Furthermore, use ground penetrating radar to detect and identify the fracture concentration area through the reflected signal, measure the rock mass mechanical parameters of the rock mass through the core samples obtained by drilling, and collect the distribution data of joints and fractures through borehole imaging technology;

[0016] Detect the changes in the surrounding rock and geological structure in front of the tunnel and collect seismic detection data; after converging the groundwater distribution data, generate a three-dimensional geological structure map of the surrounding rock through seismic imaging methods from the geological detection data.

[0017] Furthermore, according to the characteristics of different surrounding rock types, use empirical formulas to estimate and obtain the initial surrounding rock loose circle; input the rock mass mechanical parameters of the surrounding rock, and after setting the boundary conditions in advance, use a three-dimensional numerical model to simulate the excavation process of the tunnel section, and obtain the corresponding simulated excavation data after applying the influence of the initial support.

[0018] Furthermore, extract the main stress distribution map and plastic zone range data of the surrounding rock, compare the results of the empirical formula and the output of the numerical simulation, and if the existing deviation is greater than expected, iteratively optimize the estimation results of the loose circle;

[0019] Match the layout parameters of the support according to the estimated initial loose circle depth and distribution range, fuse the loose circle distribution with the support layout parameters, and mark the coverage range and key parameters of the support design.

[0020] Furthermore, at the beginning of construction, arrange monitoring points according to the tunnel section size, determined construction method and geological conditions, and periodically collect monitoring data by the monitoring equipment array, and record the time, location and initial state of the deformation data, including,

[0021] The point displacement of the tunnel surrounding rock and support, the deformation data of the entire tunnel section, the internal strain change data and local strain data of bolts, steel frames and shotcrete, and the ground settlement data.

[0022] Further, after collecting and analyzing monitoring data, including surrounding rock displacement, support deformation, and surface settlement data, the warning value V is generated according to the following method final :

[0023]

[0024] In the formula: W h is the horizontal displacement weight matrix, U is the displacement vector, W s is the support deformation rate weight matrix, is the support deformation rate vector, W d is the settlement rate weight matrix, is the surface settlement rate vector; σ(R(t)) is the surrounding rock stress tensor, representing the stress state of the surrounding rock at different times t, σ(R(t)) is the surrounding rock stress tensor, representing the stress state of the surrounding rock at different times t, is the stress divergence.

[0025] Further, if the obtained warning value V final is lower than the first warning threshold, no additional treatment is required; if the obtained warning value V final is between the first and second warning thresholds, the monitoring intensity and support strength are enhanced; if the obtained warning value V final is higher than the second warning threshold, excavation is stopped and additional support measures are added.

[0026] Further, combining real-time monitoring data, including support displacement data, support strain data, and settlement data; according to the increment of real-time monitoring data, the adjusted empirical formula is used to update the range of the loosening zone;

[0027] Taking the adjusted dynamic loosening zone range as the initial condition of the inversion model, combining the surrounding rock classification, rock mass mechanical parameters, and monitoring data of the construction stage to adjust the relevant parameters in the inversion model; based on the loosening zone distribution model obtained by stress inversion, the calculation results are corrected through real-time data to obtain the dynamic depth and expansion range of the surrounding rock loosening zone.

[0028] Further, on the basis of obtaining the initial surrounding rock loosening zone, after obtaining the actual depth, distribution range, and expansion rate of the current surrounding rock loosening zone, the deviation coefficient D is generated total , the method is as follows:

[0029]

[0030] In the formula: R current (t,x,y) represents the real-time loosening zone depth at time t and position (x,y), R initial(x, y) is the depth of the initial design loosening zone, dV is the spatial volume element, representing the volume integral of the entire construction area; dt is the time integral element, representing the time span of the construction progress.

[0031] Furthermore, determine the adjustment measures based on the deviation coefficient: among them, if the obtained deviation coefficient is greater than the design value, the support strength should be increased, such as adding bolts or thickening the shotcrete; if the obtained deviation coefficient is less than the design value, optimize the support layout, reduce costs, and send an optimization instruction to the outside; after receiving the optimization instruction, use the pre-trained multi-objective optimization algorithm to optimize the support specification parameters; output the dynamically adjusted support specification parameters, including bolt layout parameters, shotcrete thickness and strength grade, steel frame spacing and model.

[0032] (III) Beneficial effects

[0033] The present invention provides a tunnel dynamic design method based on the deformation of advanced support, having the following beneficial effects:

[0034] 1. The output two-dimensional cross-sectional view, three-dimensional distribution map, and displacement contour lines of the loosening zone range can provide support for support design and construction process adjustment; according to the distribution of the plastic zone volume and the main stress concentration area, optimize the construction footage and support timing to reduce construction risks.

[0035] 2. By simulating the deformation of the surrounding rock during the excavation process through a three-dimensional numerical model, the expansion range and depth of the loosening zone can be accurately predicted, providing an accurate basis for support design; dynamically simulating the role of the support can help optimize the initial support design to ensure the stability of the surrounding rock during excavation; by comparing the simulation results with the estimated values of the empirical formula, the prediction accuracy of the loosening zone can be verified and the support design can be adjusted in a timely manner.

[0036] 3. According to the horizontal and vertical expansion ranges of different loosening zones, adjust the support parameters, such as bolt length, spacing, shotcrete thickness, etc., to ensure that the support measures are fully matched with the loosening zone. By adjusting the support design, especially increasing the density of the support in the stress concentration area, the safety of the support measures can be effectively enhanced.

[0037] 4. By arranging monitoring points at different positions, the deformation of the surrounding rock and the support structure can be comprehensively monitored, and potential risks can be discovered in advance; by generating a warning value V final from the monitoring data and comparing it with the set warning threshold, abnormal deformation of the surrounding rock can be detected in a timely manner. Through real-time monitoring and rapid emergency response, construction risks can be reduced.

[0038] 5. Dynamically adjust the loose circle range through real-time monitoring data, so that the loose circle can more accurately reflect the surrounding rock deformation during construction. According to the dynamic adjustment of the loose circle, it is possible to evaluate in real time whether the support design is sufficient to cover the loose circle, and the support design can be adjusted in time to avoid the failure of the support system.

[0039] 6. By using the real-time updated loose circle range as the initial condition of the inversion model, the calculation results can be corrected to ensure that the inversion model reflects the true surrounding rock deformation. Through stress inversion calculation, the dynamic loose circle range of the surrounding rock can be accurately predicted, providing more reliable data support for the support design. According to the inversion results, the support design parameters are dynamically adjusted to ensure that the support scheme is completely matched with the loose circle range, improving the support effect.

[0040] 7. By comparing the real-time loose circle with the initial design value, it is possible to judge whether it is necessary to strengthen the support according to the deviation coefficient, adjust the support strength in time, optimize the support design and reduce the construction cost. By dynamically adjusting the support parameters, the deformation of the surrounding rock can be effectively controlled, avoiding the risks caused by insufficient support. Through the optimization algorithm, the support design can be dynamically adjusted according to the real-time data and the construction process, making the construction process more flexible and controllable. Description of the Drawings

[0041] Figure 1 It is a schematic flow chart of the tunnel dynamic design method based on the advanced support deformation of the present invention. Detailed Embodiment

[0042] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0043] Please refer to Figure 1 , the present invention provides a tunnel dynamic design method based on the advanced support deformation,

[0044] Step 1: Use a variety of detection methods to collect the geological detection data of the surrounding rock, initially estimate the range of the loose circle in combination with the empirical formula, and analyze the deformation of the surrounding rock during the excavation process through three-dimensional numerical simulation, and output the two-dimensional cross-sectional view or three-dimensional spatial distribution map of the initial surrounding rock loose circle;

[0045] The content of the above Step 1 includes the following:

[0046] Step 101: Use a ground-penetrating radar to detect and identify the fracture concentration area through the reflection signal;

[0047] Core samples obtained by drilling are used to measure the rock mass mechanical parameters of the rock mass, such as the rock mass strength σc, density ρ, elastic modulus E and other test data. Distribution data of joints and fissures, such as fissure density and azimuth, are collected through borehole imaging technology.

[0048] The propagation characteristics of seismic waves are used to detect changes in the surrounding rock and geological structure in front of the tunnel, and seismic test data such as longitudinal wave velocity, transverse wave velocity, wave velocity ratio, seismic wave amplitude attenuation and seismic reflection coefficient are collected.

[0049] After summarizing the obtained rock mass mechanical parameters, faults, fissures, seismic test data and groundwater distribution data of the rock mass, a geological test data set is generated. Through seismic imaging methods, such as velocity inversion, waveform inversion and full-wavefield modeling, a three-dimensional geological structure diagram of the surrounding rock is generated from the geological test data. At this time, the three-dimensional geological model generated by wave velocity inversion can intuitively display the stratification, faults, fissures and water-bearing areas of the surrounding rock in front of the tunnel.

[0050] It should be noted that the advanced seismic wave method sends seismic waves inside the tunnel by applying artificial seismic sources (such as explosion sources, hammer sources, vibration sources), and the receiver records the propagation time, amplitude and attenuation characteristic data of the seismic waves in the surrounding rock. Among them, the longitudinal wave (P wave): mainly reflects the density and elastic modulus of the rock mass, and is sensitive to the groundwater distribution and weak zones. The transverse wave (S wave): reflects the shear strength of the rock mass and can better identify fault fracture zones and weak surrounding rocks.

[0051] Furthermore, the source position is usually set at the tunnel face or near the tunnel face to ensure that the seismic waves can cover the advanced detection range. The source form is usually an explosion source, a hammer source or a directional vibration source, and a suitable form is selected according to the tunnel depth and rock mass properties.

[0052] An array of receivers is arranged along the tunnel wall to form a linear or planar acquisition layout. According to the tunnel scale and accuracy requirements, the receiver spacing is usually 0.5 - 1 meter. Among them, the number of receivers arranged determines the seismic wave detection accuracy, and the density needs to be increased in the weak surrounding rock area. After the excitation source is triggered, the receiver records the changes in the time, waveform and amplitude of the seismic waves propagating from the source to different parts of the surrounding rock. To ensure the sampling accuracy, the sampling frequency is usually 10 times the main frequency of the seismic wave.

[0053] Step 102: According to the characteristics of different surrounding rock types (such as self-stabilization time, development law of loose circle), an initial surrounding rock loose circle is estimated using empirical formulas (such as empirical formula for loose circle depth). Among them, the empirical formulas include empirical formulas based on surrounding rock coefficients, formulas based on surrounding rock strength and stress, and time models of loose circle depth, etc.

[0054] Empirical formula for self-stabilization time: Where: k is the surrounding rock coefficient, σmax σ is the maximum principal stress of the surrounding rock, and L is the tunnel span; the formula for the depth of the loosened zone: d = k·H; where: d is the depth of the loosened zone (m), H is the tunnel excavation height (m), and k is the surrounding rock coefficient, which depends on the surrounding rock type; the time model of the depth of the loosened zone, the formula: d(t) = d0 + v d ·t; where: d is the initial depth of the loosened zone (m); Ua is the expansion rate of the loosened zone (m / day), and t is the time (day);

[0055] Input the rock mass mechanical parameters of the surrounding rock, including elastic modulus E, Poisson's ratio ν, compressive strength, cohesion c, and internal friction angle φ, etc. After setting the boundary conditions in advance, among them, apply the actual in-situ stress field and tunnel excavation load. The top boundary is a free boundary, and the bottom boundary and side wall boundaries are set with constraint conditions; use a three-dimensional numerical model to simulate the excavation process of the tunnel section. Commonly used software includes FLAC3D, ABAQUS, PLAXIS, etc.; during the excavation process, apply the influence of the initial support (such as shotcrete, bolts, etc.), and obtain the corresponding simulated excavation data;

[0056] The range of the loosened zone estimated by the empirical formula (such as the preliminary expansion range in the horizontal and vertical directions) can be used as the input reference for the three-dimensional numerical model. Set reasonable boundary conditions and preliminary excavation parameters. The results of the empirical formula can also be used to verify the output accuracy of the three-dimensional numerical simulation, providing a basis for the subsequent determination of the loosened zone range.

[0057] Step 103: Simulate the dynamic process of tunnel excavation in the three-dimensional numerical model. In the excavation stage, use the step-by-step loading method, that is, gradually release the in-situ stress of the surrounding rock according to the construction footage, and at the same time dynamically apply the initial support (such as bolts, shotcrete), and consider the influence of the time effect of the initial support on the loosened zone range,

[0058] The input parameters for simulating the excavation include the physical and mechanical properties of the surrounding rock and the distribution of the in-situ stress field, and determine the initial excavation range in combination with the preliminary estimated values of the empirical formula;

[0059] The extracted distribution map of the principal stress of the surrounding rock and the data of the plastic zone range can be used to verify whether the range of the loosened zone estimated by the empirical formula in Step 102 is accurate. Compare the results of the empirical formula and the output of the numerical simulation (such as the horizontal expansion distance, vertical expansion distance, and plastic zone volume). If the existing deviation is greater than the expected value, it is necessary to adjust the parameters of the three-dimensional numerical model (such as the initial stress field, surrounding rock strength index, etc.) and re-simulate to iteratively optimize the estimation results of the loosened zone;

[0060] Extract the principal stress distribution diagram of the surrounding rock in the 3D numerical model and analyze the stress concentration area to obtain the horizontal displacement, vertical displacement, and total displacement field distribution of the surrounding rock; use the Mohr-Coulomb yield criterion to determine whether the surrounding rock has entered the plastic state. If the shear stress τ of the surrounding rock exceeds the shear strength, then this area is regarded as the plastic zone, and the range of the plastic zone is output as a reference for the loosening zone.

[0061] Output the two-dimensional cross-sectional diagram or three-dimensional spatial distribution diagram of the initial surrounding rock loosening zone from the 3D numerical model, and mark the range of the plastic zone, displacement contour lines reflecting the deformation amplitude of the surrounding rock, and the principal stress distribution diagram in the figure; among them, the main parameters of the loosening zone range include the maximum expansion distance dh in the horizontal direction, the maximum expansion distance dv in the vertical direction, and the plastic zone volume Vp.

[0062] When in use, combine the content in steps 101 to 103:

[0063] The output two-dimensional cross-sectional diagram, three-dimensional distribution diagram, and displacement contour lines of the loosening zone range can provide support for the support design and construction process adjustment; for example, according to the maximum horizontal expansion distance and maximum vertical expansion distance of the loosening zone, dynamically adjust the support parameters such as the bolt arrangement spacing and the thickness of shotcrete; according to the distribution of the plastic zone volume and the principal stress concentration area, optimize the construction footage and support timing to reduce construction risks.

[0064] Through the empirical formula combined with the physical and mechanical parameters of the surrounding rock, the preliminary estimated range of the loosening zone can be quickly obtained, which is convenient for the preliminary planning of the support design: taking the result of the empirical formula as the input reference of the 3D numerical model can verify the accuracy of the numerical simulation and adjust the support design according to the actual situation: based on the estimated loosening zone range, the support design can be initially matched with the loosening zone range to ensure the stability of the support system.

[0065] By simulating the deformation of the surrounding rock during the excavation process through the 3D numerical model, the expansion range and depth of the loosening zone can be accurately predicted, providing an accurate basis for the support design; dynamically simulating the role of the support (such as bolts, shotcrete, etc.) can help optimize the initial support design to ensure the stability of the surrounding rock during the excavation process; by comparing the simulation results with the estimated values of the empirical formula, the prediction accuracy of the loosening zone can be tested and the support design can be adjusted in time.

[0066] Step 2: After matching the corresponding support plan according to the estimated loosening zone range, use the pre-trained particle swarm optimization algorithm to adjust the current support plan with the displacement control value of the surrounding rock as the optimization constraint condition and the construction safety and economy as the optimization objectives.

[0067] The said step 2 includes the following content:

[0068] Step 201: Match the layout parameters of the support according to the estimated initial loosening circle depth and distribution range, including the length, spacing, and quantity of bolts, the thickness and strength of shotcrete, the type and layout spacing of steel frames, etc. For example, the support design needs to be closely matched with the loosening circle range: the bolt length should be 1.2 - 1.5 times the loosening circle depth, and the bolt spacing is dynamically adjusted according to the uniformity of the loosening circle distribution, and the spacing is reduced in the stress concentration area (such as reduced from 1.5 m to 0.8 m).

[0069] The thickness of the shotcrete is calculated as 10% - 15% of the loosening circle depth, and the support coverage range exceeds the loosening circle expansion range by at least 20% - 30% to improve the support safety; the layout spacing of the steel frames is adjusted in combination with the tunnel section size and the surrounding rock category, and is densified in the area with a larger loosening circle range.

[0070] In the two-dimensional sectional view, integrate the loosening circle distribution (such as stress contour lines, plastic zone range) with the support layout parameters, and mark the coverage range and key parameters of the support design to ensure that the layout ranges of bolts, shotcrete, and steel frames completely cover the loosening circle, and highlight the changes in support parameters in different areas (such as denser support in the stress concentration area).

[0071] Adjust the support parameters such as bolt length, spacing, and shotcrete thickness according to the horizontal and vertical expansion ranges of different loosening circles to ensure that the support measures are completely matched with the loosening circle. By adjusting the support design, especially increasing the density of the support in the stress concentration area, the safety of the support measures can be effectively enhanced; under different surrounding rock conditions, the support parameters can be flexibly adjusted to cope with different deformation and stress states of the surrounding rock.

[0072] Step 202: Combine the tunnel section size, take improving economy and safety as the optimization goal, use the pre-trained particle swarm optimization algorithm to optimize the current support scheme with the loosening circle range parameters as the input and the surrounding rock displacement control value as the optimization constraint condition, and output the optimal combination of support parameters, including bolt spacing, concrete thickness, and steel frame spacing, etc. Among them, the surrounding rock displacement control value usually refers to the maximum allowable values of the horizontal displacement, vertical displacement, and total displacement of the surrounding rock during the tunnel or underground excavation process. The displacement control value is not only related to the direct deformation of the surrounding rock, but also closely related to the bearing capacity of the support system, construction safety, and structural stability.

[0073] When in use, combine the content in Steps 201 and 202:

[0074] The support parameters are automatically adjusted through the particle swarm optimization algorithm, so that the support design can meet the safety requirements and achieve economic optimization. By optimizing the support scheme, the construction cost can be reduced and the construction efficiency can be improved while ensuring safety. The optimization algorithm can be used to reduce manual intervention, realize the intelligence and automation of support design, and improve the design accuracy and execution effect.

[0075] Step 3: Set up monitoring points during the construction process and collect monitoring data in real time, and construct the warning value V based on the collected monitoring data. final , according to the warning value V final After determining the warning level with the set warning threshold, take corresponding emergency response measures;

[0076] The step three includes the following contents:

[0077] Step 301: At the beginning of construction, monitoring points are arranged according to the tunnel section size, the determined construction method and the geological conditions. The monitoring points should cover the front of the tunnel face, the tunnel vault, the side wall and the tunnel periphery. The monitoring equipment array periodically collects monitoring data and records the time, position and initial state of the deformation data, including:

[0078] The point displacement of the tunnel surrounding rock and support is accurately measured using a total station, which is arranged in a stable position outside the tunnel face, and a reflective prism is installed at the monitoring point; a laser scanner is used to obtain deformation data of the entire tunnel section, and optical fiber sensors are used to monitor the internal strain changes of anchor rods, steel frames and shotcrete. The optical fiber sensors are buried in the key stress-bearing parts of the support structure;

[0079] The resistance strain gauge is installed on the steel frame or anchor surface to collect local strain data, and the positioning module is used to monitor the surface settlement in real time over a wide area. The base station and monitoring points are distributed above the construction area and surrounding buildings.

[0080] Use a level to accurately monitor ground settlement, with monitoring points arranged along the tunnel axis, usually at intervals of 10-30m;

[0081] Summarize the collected point displacements of tunnel surrounding rock and support, deformation data of the entire section of the tunnel, internal strain change data of anchors, steel frames and shotcrete, local strain data, and surface settlement data;

[0082] By deploying monitoring points at different locations, the deformation of surrounding rock and support structure can be fully monitored, potential risks can be discovered in advance, and precise instruments (such as total stations, laser scanners, fiber optic sensors, etc.) can be used to accurately monitor the deformation of surrounding rock and support structure, providing accurate data support for subsequent decision-making;

[0083] Step 302: After collecting and analyzing monitoring data, including surrounding rock displacement, support deformation and surface settlement data, a warning value V is generated according to the following method:final :

[0084]

[0085] In the formula: W h is the horizontal displacement weight matrix, which represents the importance of the horizontal displacements of different monitoring points in the comprehensive warning value. The elements of the matrix reflect the contributions of each monitoring point to the displacement of the overall system. U is the displacement vector, which represents the horizontal displacement data (such as the displacement of the surrounding rock) of each monitoring point. This data is collected by monitoring equipment (such as total station, laser scanner, etc.) and reflects the deformation of the surrounding rock during the tunnel construction process. W s is the support deformation rate weight matrix, which represents the weight of the support deformation rate in the warning value. Different support structures (such as bolts, steel frames, shotcrete, etc.) have different influence degrees on the deformation rate. The weight matrix is used to weight these rate data. is the support deformation rate vector, which represents the deformation rate of the support structure (such as bolts, steel frames, etc.). It is real-time monitored by deformation sensors, such as fiber optic sensors, strain gauges, etc., and reflects the working state of the support system; W d is the settlement rate weight matrix, which represents the weight of the ground surface settlement rate in the warning value. The settlement rates of different monitoring points may have different influence weights on safety. The weight matrix is used to weight each settlement rate data. is the ground surface settlement rate vector, which represents the rate of ground surface settlement. It is collected by settlement monitoring equipment (such as level, ground surface settlement gauge, etc.) and reflects the ground surface deformation situation during the construction process; σ(R(t)) is the surrounding rock stress tensor, which represents the stress state of the surrounding rock at different times t. The stress tensor takes into account the anisotropy of the surrounding rock and different types of stresses (such as axial stress, shear stress, etc.); σ(R(t)) is the surrounding rock stress tensor, which represents the stress state of the surrounding rock at different times t. The stress tensor takes into account the anisotropy of the surrounding rock and different types of stresses (such as axial stress, shear stress, etc.). is the stress divergence: which represents the spatial variation of the stress in the surrounding rock. The divergence operation reflects the diffusion of the stress in space and is related to the evolution of the surrounding rock loosening zone and the stress transfer during the excavation process;

[0086] According to the historical data and the management expectations of the construction state, the first and second warning thresholds are set in advance, where the second warning threshold is higher than the first warning threshold;

[0087] If the obtained warning value V final is lower than the first warning threshold, no additional treatment is performed;

[0088] If the obtained warning value V final is between the first and second warning thresholds, the monitoring density and the support strength are enhanced;

[0089] If the obtained warning value Vfinal If it is higher than the second warning threshold, immediately stop the excavation and add support measures; then the construction plan can be adjusted, such as shortening the excavation footage, increasing the length or quantity of bolts, thickening the shotcrete, adding small pre - driven pipes, etc.

[0090] During use, combine the content in steps 301 and 302:

[0091] Generate the warning value V through the monitoring data final And compare it with the set warning threshold. It can be detected in time when the surrounding rock deforms abnormally, ensuring construction safety. Through real - time monitoring and rapid emergency response, construction risks can be reduced, and catastrophic accidents can be avoided. By detecting and dealing with deformation problems in advance, accidents caused by excessive deformation during construction can be avoided, ensuring the smooth progress of the construction process.

[0092] Step Four: Dynamically adjust the loosening zone in combination with real - time monitoring data. Based on the adjusted loosening zone range, use the inversion model to calculate the dynamic loosening zone distribution of the surrounding rock, draw the two - dimensional profile distribution diagram or three - dimensional model of the loosening zone, and continuously update according to the construction process and monitoring data;

[0093] The said Step Four includes the following content:

[0094] Step 401: Combine real - time monitoring data, including support displacement data: Monitor the displacement of the support structure (such as bolts, shotcrete, steel frames, etc.) to reflect the deformation degree of the surrounding rock and the support structure; support strain data: Monitor the strain changes of the surrounding rock and the support structure through strain gauges or fiber optic sensors to obtain the stress condition of the surrounding rock; settlement data: Monitor the settlement of the surrounding rock and the tunnel floor to reflect the compaction or loosening of the surrounding rock.

[0095] According to the increments of real - time monitoring data (displacement, strain, settlement, etc.), use the adjusted empirical formula to update the range of the loosening zone; the adjusted depth and expansion range of the loosening zone should reflect the deformation of the surrounding rock and the support during the current construction process. For example, the displacement increment and strain increment can be used to adjust the depth and expansion range of the loosening zone:

[0096] The displacement control formula is as follows: d h (t) = d h0 +k v ·Δu; d v (t) = d v0 +k v ·Δu;

[0097] Where: d h (t), d v (t) are the horizontal and vertical expansion depths of the loosening zone at the current moment respectively; d h0 , d v0is the initial depth of the loosening zone, Δu is the displacement increment monitored in real time, and k T is the relaxation coefficient of the surrounding rock material, which can be calibrated through test data; the strain control formula is as follows:

[0098] d h (t) = d h0 ·(1 + Δε / ε y )

[0099] where: Δε is the monitored strain increment of the surrounding rock, and ε y is the yield strain of the surrounding rock;

[0100] Dynamically adjust the loosening zone range through real-time monitoring data (displacement, strain, etc.) so that the loosening zone can more accurately reflect the deformation of the surrounding rock during construction. According to the dynamic adjustment of the loosening zone, it is possible to evaluate in real time whether the support design is sufficient to cover the loosening zone, so as to adjust the support design in time and avoid the failure of the support system;

[0101] Step 402: Take the dynamically adjusted loosening zone range (such as the horizontally extended depth and vertical depth updated in real time) in Step 401 as the initial condition of the inversion model, and adjust the relevant parameters in the inversion model in combination with the surrounding rock classification, rock mass mechanical parameters, and monitoring data during the construction stage (such as support displacement, surrounding rock deformation, etc.);

[0102] Based on the loosening zone distribution model obtained by stress inversion, correct the calculation results through real-time data to obtain the dynamic depth and expansion range of the surrounding rock loosening zone. Use the inversion results to draw a two-dimensional profile distribution map or three-dimensional model of the loosening zone, and continuously update according to the construction process and monitoring data to display the expansion range and change trend of the loosening zone;

[0103] After outputting the loosening zone distribution map, verify the inversion results through the following methods:

[0104] Compare with monitoring data: Compare the inversion results (such as the plastic zone range, principal stress distribution) with the monitored displacement field and strain field distributions to verify whether the inversion results are reasonable;

[0105] Compare with numerical simulation results: Compare the inversion results with the simulation results of a three-dimensional numerical model (such as FLAC3D, ABAQUS) for calibration to ensure model consistency;

[0106] Feedback to the support design: Dynamically optimize the support parameters (such as increasing the bolt length, adjusting the shotcrete thickness, etc.) according to the change trend of the loosening zone range (such as expansion rate, range increment).

[0107] When in use, combine the content in Steps 401 and 402:

[0108] By taking the range of the loosening zone with real-time updates as the initial condition of the inversion model, the calculation results can be corrected to ensure that the inversion model reflects the actual surrounding rock deformation. Through stress inversion calculation, the dynamic loosening zone range of the surrounding rock can be accurately predicted, providing more reliable data support for the support design. According to the inversion results, the support design parameters can be dynamically adjusted to ensure that the support plan is fully matched with the loosening zone range, improving the support effect.

[0109] Step Five: Compare the range of the loosening zone monitored in real time with the initial design value to generate a deviation coefficient D total And determine whether it is necessary to adjust the support strength, including adding support measures or dynamically optimizing the support parameters through a multi-objective optimization algorithm;

[0110] The above Step Five includes the following contents:

[0111] Step 501: Compare the real-time loosening zone range with the initial design value. Among them, on the basis of obtaining the initial surrounding rock loosening zone, after obtaining the actual depth, distribution range and expansion rate of the current surrounding rock loosening zone, generate the deviation coefficient D total , the method is as follows:

[0112]

[0113] In the formula: R current (t, x, y) represents the real-time loosening zone depth at time t and position (x, y), and R initial (x, y) is the depth of the initial design loosening zone, usually a spatial field, representing the loosening zone range during design; dV is the spatial volume element, representing the volume integral of the entire construction area; dt is the time integral element, representing the time span of the construction progress;

[0114] Determine the adjustment measures based on the deviation coefficient: Among them, if the obtained deviation coefficient is greater than the design value, the support strength should be increased, such as adding bolts or thickening the shotcrete; if the obtained deviation coefficient is less than the design value, optimize the support layout to reduce costs, and at this time, send an optimization instruction to the outside;

[0115] Step 502: After receiving the optimization instruction, take improving safety and economy as the optimization goals, and use a pre-trained multi-objective optimization algorithm to optimize the support specification parameters; output the dynamically adjusted support specification parameters, including bolt arrangement parameters (length, spacing, quantity, etc.), shotcrete thickness and strength grade, steel frame spacing and model;

[0116] When in use, combine the contents in Steps 501 and 502:

[0117] By comparing the real-time loosening zone with the initial design value, it is possible to judge whether it is necessary to strengthen the support according to the deviation coefficient, and timely adjust the support strength, which can ensure construction safety. If the deviation coefficient Dtotal Less than expected, the support design can be optimized to reduce unnecessary support materials, thereby reducing construction costs;

[0118] Through the multi-objective optimization algorithm, safety and economy can be considered simultaneously. Under the premise of ensuring construction safety, the support parameters can be optimized to improve project efficiency. By dynamically adjusting the support parameters, the deformation of the surrounding rock can be effectively controlled, and the risks caused by insufficient support can be avoided. Through the optimization algorithm, the support design can be dynamically adjusted according to real-time data and the construction process, making the construction process more flexible and controllable.

[0119] Those of ordinary skill in the art can realize that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed in hardware or software depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of this application.

[0120] Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working processes of the systems, devices, and units described above can refer to the corresponding processes in the foregoing method embodiments and will not be repeated here.

[0121] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units is only for some logical function divisions. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed couplings or direct couplings or communication connections to each other can be through some interfaces. The indirect couplings or communication connections of the devices or units can be in electrical, mechanical, or other forms.

[0122] The units described as separate components may or may not be physically separated. The components displayed as units may or may not be physical units, that is, they can be located in one place or distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0123] As described above, it is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present application can easily think of changes or substitutions, which should all be covered within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims described above.

Claims

1. A tunnel dynamic design method based on the deformation of advanced support, characterized in that: including Collecting geological detection data of surrounding rock using multiple detection methods, preliminarily estimating the range of the loosening zone, analyzing the deformation of the surrounding rock during the excavation process through three-dimensional numerical simulation, and outputting a two-dimensional cross-sectional diagram or three-dimensional spatial distribution map of the initial surrounding rock loosening zone; After matching the corresponding support scheme according to the estimated range of the loosening zone, using the displacement control value of the surrounding rock as the optimization constraint condition and construction safety and economy as the optimization objectives, adjusting the current support scheme using a pre-trained particle swarm optimization algorithm; During the construction process, monitoring points are arranged and monitoring data is collected in real time, and warning values are constructed from the collected monitoring data , and after determining the early warning level based on the warning value and the set warning threshold, corresponding emergency response measures are taken; Dynamically adjusting the loosening zone in combination with real-time monitoring data, based on the adjusted range of the loosening zone, predicting the dynamic range of the loosening zone of the surrounding rock using an inversion model, drawing a two-dimensional profile distribution map or three-dimensional model of the loosening zone, and continuously updating according to the construction process and monitoring data; Compare the loosening zone range predicted by the inversion model with the initial design value to generate a deviation coefficient And determine whether it is necessary to adjust the support strength, including increasing support measures or dynamically optimizing support parameters through a multi-objective optimization algorithm; After collecting and analyzing monitoring data, including surrounding rock displacement, support deformation, and ground settlement data, warning values are generated according to the following methods : ； In the formula: is the horizontal displacement weight matrix, is the displacement vector, is the support deformation rate weight matrix, is the support deformation rate vector, is the settlement rate weight matrix, is the ground surface settlement rate vector; is the surrounding rock stress tensor, representing the stress state of the surrounding rock at different times ; is the surrounding rock stress tensor, representing the stress state of the surrounding rock at different times ; is the stress divergence.

2. The tunnel dynamic design method based on the deformation of advanced support according to claim 1, characterized in that: Using ground penetrating radar to detect and identify the fracture concentration area through reflection signals, measuring the rock mass mechanical parameters of the rock mass through the core samples obtained by drilling, and collecting the distribution data of joints and fractures through borehole imaging technology; Detecting the changes in the surrounding rock and geological structure in front of the tunnel, and collecting seismic detection data; after converging the groundwater distribution data, generating a three-dimensional geological structure map of the surrounding rock from the geological detection data through seismic imaging method.

3. The tunnel dynamic design method based on the deformation of advanced support according to claim 2, characterized in that: According to the characteristics of different surrounding rock types, using empirical formulas to estimate and obtain the initial surrounding rock loosening zone; inputting the rock mass mechanical parameters of the surrounding rock, after setting the boundary conditions in advance, using a three-dimensional numerical model to simulate the excavation process of the tunnel section, and obtaining the corresponding simulated excavation data after applying the influence of the initial support, wherein the empirical formulas include empirical formulas based on the surrounding rock coefficient, formulas based on the surrounding rock strength and stress, and time models of the loosening zone depth.

4. The tunnel dynamic design method based on the deformation of advanced support according to claim 3, characterized in that: Extracting the main stress distribution map and plastic zone range data of the surrounding rock, comparing the results of estimating the initial surrounding rock loosening zone obtained by empirical formulas with the output of numerical simulation, and if the deviation exists and is greater than expected, iteratively optimizing the estimation results of the loosening zone; Matching the layout parameters of the support according to the estimated initial loosening zone depth and distribution range, integrating the loosening zone distribution with the support layout parameters, and marking the coverage range and key parameters of the support design.

5. The tunnel dynamic design method based on the deformation of advanced support according to claim 4, characterized in that: At the beginning of construction, arranging monitoring points according to the tunnel section size, determined construction method and geological conditions, periodically collecting monitoring data by the monitoring equipment array, and recording the time, location and initial state of the deformation data, including Point displacement of tunnel surrounding rock and support, deformation data of the whole tunnel section, internal strain change data and local strain data of bolts, steel frames and shotcrete, and ground settlement data.

6. The tunnel dynamic design method based on the deformation of advanced support according to claim 5, characterized in that: If the obtained warning value is lower than the first warning threshold, no additional treatment is required; if the obtained warning value is between the first and second warning thresholds, enhance the monitoring density and support strength; if the obtained warning value is higher than the second warning threshold, stop the excavation and add support measures.

7. The tunnel dynamic design method based on the deformation of advanced support according to claim 6, characterized in that: Combined with real-time monitoring data, including support displacement data, support strain data, and settlement data; according to the increment of the real-time monitoring data, use the adjusted empirical formula to update the range of the loosened zone; Use the adjusted dynamic loosened zone range as the initial condition of the inversion model, and combine the surrounding rock classification, rock mass mechanical parameters, and monitoring data at the construction stage to adjust the relevant parameters in the inversion model; Based on the loosened zone distribution model obtained by stress inversion, correct the calculation results through real-time data to obtain the dynamic depth and expansion range of the surrounding rock loosened zone.

8. The tunnel dynamic design method based on the deformation of advanced support according to claim 7, wherein: On the basis of obtaining the initial surrounding rock loosening zone, a deviation coefficient is generated after obtaining the actual depth, distribution range and expansion rate of the current surrounding rock loosening zone, and the method is as follows: , as follows: ； In the formula: represents the depth of the real-time loosening zone at the moment and the position is the depth of the initially designed loosening zone; is the spatial volume element, representing the volume integral of the entire construction area; is the time integral element, representing the time span of the construction progress.

9. The tunnel dynamic design method based on the deformation of advanced support according to claim 8, wherein: Determine the adjustment measures based on the deviation coefficient: among them, if the obtained deviation coefficient is greater than the design value, increase the support strength, add bolts, and thicken the shotcrete; if the obtained deviation coefficient is less than the design value, optimize the support layout, reduce costs, and send an optimization instruction to the outside; after receiving the optimization instruction, use the pre-trained multi-objective optimization algorithm to optimize the support specification parameters; output the dynamically adjusted support specification parameters, including bolt layout parameters, shotcrete thickness and strength grade, steel frame spacing and model.

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