Intelligent three-dimensional soil pressure feedback system for surrounding rock-support system of shallow-buried super-large-section underground excavation station

Abstract

The invention provides a three-dimensional soil pressure intelligent feedback system for a surrounding rock-support system of a shallow-buried super-large-section underground excavation station, and belongs to the technical field of subway tunnel construction. The intelligent three-dimensional soil pressure feedback system for the surrounding rock-support system of the shallow-buried super-large-section underground excavation station comprises a data acquisition module, an arch effect analysis module, a three-dimensional soil pressure identification module, a feedback control module and an evaluation strategy module. According to the method, a full-chain and closed-loop intelligent response mechanism from arch effect recognition to three-dimensional soil pressure calculation and then to support strategy feedback and risk grading early warning is adopted. According to the system, arch effect coefficients are introduced into vertical, lateral and axial soil pressure calculation formulas, and dynamic correction of supporting stress by the surrounding rock self-stabilization capacity is achieved; on the basis, automatic identification and response grading output of risk points are realized by setting a delta p difference value early warning interval, constructing a pressure overrun trigger logic and combining a support design reference value and a threshold value grade.

Description

Technical Field

[0001] This invention relates to the field of subway tunnel construction technology, and more specifically, to a three-dimensional intelligent earth pressure feedback system for the surrounding rock-support system of shallow-buried ultra-large cross-section underground stations. Background Technology

[0002] Against the backdrop of rapid development of urban underground transportation, shallow-buried ultra-large cross-section tunnel-cut stations are widely used due to their minimal ground disturbance and high space utilization. However, these stations face challenges such as complex surrounding rock structures, intense stress release, and unpredictable deformation during construction, which can easily lead to surrounding rock instability, support failure, or even collapse accidents. Existing earth pressure analysis methods mainly rely on two-dimensional or simplified three-dimensional geostress initial state estimation models, combined with on-site measurement data to perform limited displacement or stress inversion analysis.

[0003] Existing technologies mostly focus on post-construction monitoring and empirical judgment of surrounding rock deformation, lacking a real-time identification mechanism for the dynamic evolution of the arching effect during construction. Especially under complex geological conditions, the surrounding rock often forms uneven stress release and transmission paths in the vertical, lateral, and axial directions, resulting in a significant arching effect, which affects the actual distribution of earth pressure. Traditional methods are difficult to accurately reflect the differences in the spatial mechanical response of surrounding rock in different areas under construction disturbance. Especially in deep foundation pits and large-section tunnels, existing technologies are prone to causing deviations between earth pressure estimation and support response. Summary of the Invention

[0004] To overcome the above deficiencies, the present invention provides a three-dimensional intelligent earth pressure feedback system for the surrounding rock-support system of shallow-buried ultra-large cross-section underground railway stations, which overcomes or at least partially solves the above technical problems.

[0005] This invention is implemented as follows:

[0006] This invention provides a three-dimensional earth pressure intelligent feedback system for the surrounding rock-support system of a shallow-buried ultra-large cross-section tunnel railway station, including a data acquisition module, an arch effect analysis module, a three-dimensional earth pressure identification module, a feedback control module, and an evaluation strategy module;

[0007] The data acquisition module is used to collect basic parameters of the surrounding rock, including: density p, water content ω, porosity n, dynamic modulus Cv, static modulus Ch and formation friction coefficient Ca, and to establish three-dimensional spatial index coordinates (i,j,k) to achieve regional modeling.

[0008] The arching effect analysis module is used to collect the arching effect behavior of the surrounding rock in the vertical, lateral, and axial directions using pressure sensors, and to calculate the vertical arching effect coefficient K. z Lateral arch effect coefficient K x With axial arch effect coefficient K y;

[0009] The three-dimensional earth pressure identification module is used to calibrate the vertical earth pressure, lateral earth pressure and axial earth pressure based on the regional model (i,j,k) established in the data acquisition module, and to perform data calibration based on the regional model (i,j,k).

[0010] The feedback control module is used to process the identified vertical earth pressure P. z Lateral earth pressure P x With axial earth pressure P y Each is compared with the design's basic threshold P. z0 P x0 With P y0 The difference ΔP was obtained by comparison. z ΔP x With ΔP y ;

[0011] The evaluation strategy module is used to set judgment thresholds: a first judgment threshold Z1, a second judgment threshold Z2, and a third judgment threshold Z3, and to combine ΔP z ΔP x With ΔP y Comparisons are made to provide early warnings and response strategies.

[0012] In a preferred embodiment, the data acquisition module includes a parameter acquisition unit, a surrounding rock zoning modeling unit, and a data normalization unit;

[0013] The parameter acquisition unit extracts the density p, water content ω, porosity n, dynamic modulus Cv, static modulus Ch and formation friction coefficient Ca from the surrounding rock through ground radar, laser scanner and core analysis.

[0014] The partitioned modeling unit divides the surrounding rock into regions (i,j,k) for modeling and establishes a coordinate grid.

[0015] The data normalization unit is used to perform dimensionless processing on density p, water content ω, porosity n, dynamic modulus Cv, static modulus Ch, and formation friction coefficient Ca, which facilitates the calculation of the vertical arching effect coefficient K. z Lateral arch effect coefficient K x and the axial arching effect coefficient K y Perform the calculation.

[0016] In a preferred embodiment, the arch effect analysis module includes a vertical arch effect analysis unit, a lateral arch effect analysis unit, and an axial arch effect analysis unit, which respectively extract the evolution trend of the arch structure in each direction and calculate K based on the tension release situation. z K x K y The specific calculation formula is as follows:

[0017]

[0018] Wherein, η1, η2, η3, and η4 represent the degree of influence of different physical properties on the vertical arch effect; p max The maximum value of the surrounding rock density affects the magnitude of earth pressure; the higher the density, the greater the earth pressure. This value is used for normalization. ω max This represents the maximum water content of the surrounding rock, which affects the magnitude of earth pressure. Higher water content results in greater soil fluidity and deformation capacity, and is used for normalization treatment; n max This represents the maximum porosity of the surrounding rock. A higher porosity indicates lower soil density and lower earth pressure, and is used for normalization. (Cv) max The maximum value of the dynamic modulus of the surrounding rock reflects its elastic recovery ability after being subjected to stress. The larger the dynamic modulus, the smaller the deformation of the surrounding rock. It is used for normalization treatment; Ch max The static modulus of the surrounding rock is the maximum value, reflecting its deformation capacity under lateral loads. A larger static modulus indicates smaller rock deformation, and it is used for normalization. Ca max This represents the maximum value of the formation friction coefficient, which affects the magnitude of soil friction. The larger the friction coefficient, the greater the soil friction. It is used for normalization treatment.

[0019] In a preferred embodiment, the three-dimensional earth pressure recognition module includes a vertical earth pressure calculation unit, a lateral earth pressure calculation unit, and an axial earth pressure calculation unit.

[0020] The vertical earth pressure calculation unit is used to calculate the vertical earth pressure P. z The result is obtained through the following formula:

[0021] P z (i,j,k)=γ×H(i,j,k)×(1-K z (i,j,k));

[0022] The lateral earth pressure calculation unit is used to calculate the lateral earth pressure P. x The result is obtained through the following formula:

[0023] P x (i,j,k)=K a ×γ×H(i,j,k)×(1-K x (i,j,k));

[0024] The axial earth pressure calculation unit is used to calculate the axial earth pressure P. y The result is obtained through the following formula:

[0025] P y (i,j,k)=λ×γ×H(i,j,k)×(1-K y(i,j,k));

[0026] Where γ is the unit weight of the surrounding rock, H(i,j,k) is the overburden thickness, λ is the axial adjustment coefficient, and K a This is the lateral pressure coefficient.

[0027] In a preferred embodiment, the feedback control module includes a stress comparison unit and a structural adjustment suggestion generation unit;

[0028] The stress comparison unit is used to analyze the identified vertical earth pressure P. z Lateral earth pressure P x With axial earth pressure P y Each is compared with the design's basic threshold P. z0 P x0 With P y0 By performing comparative calculations, the vertical difference ΔP was obtained. z Lateral difference ΔP x axial difference ΔP y As shown in the following formula:

[0029] ΔP z -P z -P z0 ;

[0030] ΔP x -P x -P x0 ;

[0031] ΔP y -P y -P y0 ;

[0032] The structure adjustment suggestion generation unit is used to output adjustment suggestions for spraying thickness, anchor bolt spacing and lining stiffness.

[0033] In a preferred embodiment, the evaluation strategy module includes a decision mechanism unit and a strategy output unit;

[0034] The determination mechanism unit is used to determine the vertical difference ΔP. z Lateral difference ΔP x axial difference ΔP y The results are compared with the preset first judgment threshold Z1, second judgment threshold Z2, and third judgment threshold Z3, respectively, where the first judgment threshold Z1 is the vertical difference ΔP. z The safety threshold is set at Z1 = 1.5 kPa, and the risk levels are divided as follows:

[0035] When ΔP z When ≤1.5 kPa, the vertical difference ΔP z Located within the safe range, indicating vertical earth pressure Pz The status is acceptable, marked as a green safe zone, and continuous monitoring is maintained without any operation required;

[0036] When 1.5 kPa ≤ ΔP z When ≤2.0 kPa, the vertical difference ΔP z Located in the warning zone, indicating vertical earth pressure P z There is a risk of settlement, and the first level of settlement has been generated, marked as a yellow area;

[0037] When ΔP z When the pressure is greater than 2.0 kPa, the vertical difference ΔP z Located in the danger zone, indicating vertical earth pressure P z There is a risk of settlement, and a second settlement level has been generated, marked as a red zone; the second settlement level is more dangerous than the first settlement level.

[0038] In a preferred embodiment, the second judgment threshold Z2 is the lateral difference ΔP. x The safety threshold, lateral earth pressure P x This will affect the lateral stability of the support structure and should be avoided from exceeding the standard range. A safety threshold of Z2 = 2.0 kPa is set, and the risk level is classified as follows:

[0039] When ΔP x When ≤1.5 kPa, the lateral difference ΔP x This indicates a satisfactory condition, with lateral earth pressure P. x The status is acceptable, marked as a green safe zone, and continuous monitoring is maintained without any operation required;

[0040] When 1.5 kPa ≤ ΔP x When ≤2.0 kPa, the lateral difference ΔP x Located in the middle of the warning area, the lateral earth pressure P x There is a risk of lateral deformation of the support structure, and the first level of support deformation risk is generated, marked as a yellow zone;

[0041] When ΔP x When the pressure is greater than 2.0 kPa, the lateral difference ΔP x Located in the danger zone, indicating lateral earth pressure P x There is a risk of lateral deformation of the support structure, and a support deformation risk level is generated, marked as a red zone; the second support deformation risk level is more dangerous than the first support deformation risk level.

[0042] In a preferred embodiment, the third judgment threshold Z3 is the axial difference ΔP. y The safety threshold, axial difference ΔP yThe axial pressure should be controlled within a suitable range to avoid excessive axial pressure causing local instability of the support structure. A safety threshold of Z3 = 2.5 kPa is set, and the risk level is classified as follows:

[0043] When ΔP y When ≤1.5 kPa, the axial difference ΔP y Located within the safe range, indicating axial earth pressure P y The status is acceptable, marked as a green safe zone, and continuous monitoring is maintained without any operation required;

[0044] When 1.5 kPa ≤ ΔP y When ≤2.0 kPa, the axial difference ΔP y Located in the warning zone, indicating axial earth pressure P y There is a risk of shear cracking, and the first shear cracking risk level is generated, marked as a yellow zone;

[0045] When ΔP y When the pressure is greater than 2.0 kPa, the axial difference ΔP y Located in the danger zone, indicating axial earth pressure P y There is a risk of shear cracking, and a second shear cracking risk level is generated, marked as a red zone. The first shear cracking risk level is more dangerous than the first shear cracking risk level.

[0046] In the above, when the difference in earth pressure in any area exceeds the corresponding threshold, the system will trigger a risk alarm and generate an early warning strategy.

[0047] In a preferred embodiment, the determination mechanism unit can also be used to comprehensively determine the stability of the surrounding rock by combining changes in earth pressure with the actual deformation of the support structure, as follows:

[0048] Safety condition: When the vertical difference ΔP z Lateral difference ΔP x axial difference ΔP y When all three are within the green safety zone, it indicates that the surrounding rock is stable;

[0049] Warning status: When the vertical difference ΔP z Lateral difference ΔP x axial difference ΔP y If any item appears in the yellow zone, the system will output the first alarm warning, indicating that there is a risk of rock collapse in the surrounding rock.

[0050] Critical situation: When the vertical difference ΔP z Lateral difference ΔP x axial difference ΔP yIf any item appears in the red zone, the system will output a second alarm warning, indicating that the stability of the surrounding rock is more serious than in the warning state;

[0051] In the first alarm warning state, the system will generate an adjustment strategy to increase the thickness of the sprayed layer by 23cm in terms of vertical, lateral and axial earth pressure. In the second alarm warning state, the system will generate an adjustment strategy to increase the thickness of the sprayed layer by 53cm in terms of vertical, lateral and axial earth pressure.

[0052] In a preferred embodiment, the strategy output unit is used to automatically trigger different response strategies based on different thresholds:

[0053] Under safe conditions, the change in earth pressure is within a safe range, the surrounding rock is stable, the support structure is normal, and the existing support design and construction plan can be maintained without any adjustments.

[0054] Based on the first alarm warning, a first strategy is generated, including: setting up temporary support and temporary bracing measures in local areas, specifically reducing the anchor bolt spacing from 1.5m×1.5m to 0.9m×1.0m;

[0055] Based on the second alarm warning, a second strategy is generated, including: immediately activating the emergency reinforcement plan, adding more anchor bolts, suspending construction in the danger zone, initiating evacuation procedures, ensuring the safety of construction personnel, and conducting a detailed stability analysis based on soil pressure changes and surrounding rock deformation data to determine an emergency response plan, specifically reducing the anchor bolt spacing from 0.9m×1.0m to 0.5m×0.8m.

[0056] The three-dimensional earth pressure intelligent feedback system for the surrounding rock-support system of shallow-buried ultra-large cross-section tunnel railway stations provided by this invention has the following beneficial effects:

[0057] 1. This system introduces a surrounding rock modeling method based on a three-dimensional spatial index (i,j,k) and a dimensionless parameter normalization mechanism, achieving high-precision, multi-dimensional, real-time information acquisition of the surrounding rock in the vertical, lateral, and axial directions. It also reflects the heterogeneity of the physical and mechanical characteristics of the surrounding rock in different areas through partitioned modeling. Compared to traditional methods relying solely on single-point monitoring or two-dimensional profile analysis, this system can comprehensively reflect the actual evolution of the strata within a spatial range. Furthermore, in terms of arch effect identification, the system establishes a multi-factor weighted model combining the density, water content, porosity, modulus, and friction parameters of the surrounding rock. This effectively overcomes the technical limitations of existing methods that fail to distinguish the degree of arch effect influence in different directions and cannot dynamically reflect the unloading behavior of the surrounding rock structure in real time. This significantly improves the accuracy and adaptability of arch effect identification, providing scientific and reliable data support for subsequent earth pressure calculations and construction response.

[0058] 2. This system features a complete, closed-loop intelligent response mechanism, from arch effect identification to three-dimensional earth pressure calculation, and then to support strategy feedback and risk classification early warning. By incorporating the arch effect coefficient into the calculation formulas for vertical, lateral, and axial earth pressure, the system achieves dynamic correction of the support stress based on the "self-stabilizing capacity of the surrounding rock." Furthermore, by setting a Δp difference early warning interval and constructing a pressure over-limit trigger logic, combined with support design benchmark values ​​and threshold levels, the system achieves automatic identification of risk points and graded response output. The system not only automatically generates local support control suggestions but also possesses continuous learning and model update capabilities, automatically adjusting parameter correction strategies based on historical errors, significantly improving the stability assessment capability and response speed of the entire tunnel support system in complex geological environments. Attached Figure Description

[0059] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0060] Figure 1 This is a system overall flowchart provided by an embodiment of the present invention. Detailed Implementation

[0061] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0062] Reference Figure 1 The present invention provides a technical solution: a three-dimensional earth pressure intelligent feedback system for the surrounding rock-support system of a shallow buried ultra-large cross-section tunnel station, including a data acquisition module, an arch effect analysis module, a three-dimensional earth pressure identification module, a feedback control module and an evaluation strategy module;

[0063] The data acquisition module is used to collect basic parameters of the surrounding rock, including: density p, water content ω, porosity n, dynamic modulus Cv, static modulus Ch and formation friction coefficient Ca, and to establish three-dimensional spatial index coordinates (i,j,k) to achieve regional modeling.

[0064] The data acquisition module includes a parameter acquisition unit, a surrounding rock zoning modeling unit, and a data normalization unit. The data acquisition module realizes accurate perception and regional modeling of the geological parameters of the surrounding rock in the construction section, providing a real and quantifiable data basis for subsequent three-dimensional earth pressure calculation and arch effect identification.

[0065] The parameter acquisition unit extracts density p, water content ω, porosity n, dynamic modulus Cv, static modulus Ch and formation friction coefficient Ca from the surrounding rock through ground-penetrating radar, laser scanner and core drilling analysis. Ground-penetrating radar, laser scanner and core drilling sampling technology are used to measure the physical properties of the surrounding rock at the construction site. The data are distributed according to the three-dimensional spatial coordinates (i,j,k) to reflect the spatial differences.

[0066] For example, the collected data is:

[0067] Density p = 2.4 g / cm³ 3 ;

[0068] Moisture content ω = 12%;

[0069] Porosity n = 28%;

[0070] Dynamic modulus Cv = 180 MPa;

[0071] Static modulus Ch = 95 MPa;

[0072] The formation friction coefficient Ca = 0.36;

[0073] All parameters were obtained by setting up monitoring points on site at different spatial coordinates (i,j,k) to ensure that the data is representative of the region.

[0074] The partitioned modeling unit divides the surrounding rock into regional modeling areas (i,j,k), establishes a coordinate grid, and calculates and calibrates the density p, water content ω, porosity n, dynamic modulus Cv, static modulus Ch, and formation friction coefficient Ca data collected in the regional modeling (i,j,k) to ensure the subsequent application of the vertical arching effect coefficient K. z Lateral arch effect coefficient K x and the axial arching effect coefficient K y To ensure the accuracy of the calculations, the tunnel space is divided into multiple three-dimensional volume units, and a unique index is established for each unit (i,j,k) to guarantee the location accuracy, continuity, and precision of subsequent calculations.

[0075] The partition modeling unit divides the tunnel structure into three-dimensional spatial cells along the longitudinal (i), transverse (j), and vertical (k) directions. Each cell represents a volume micro-region, which is the basic spatial unit for collecting parameters and subsequent calculations. For example, (3,2,5) represents the spatial unit in the 3rd segment longitudinally, the 2nd column transversely, and the 5th layer vertically.

[0076] The data normalization unit is used to perform dimensionless processing on density p, water content ω, porosity n, dynamic modulus Cv, static modulus Ch, and formation friction coefficient Ca, which facilitates the calculation of the vertical arching effect coefficient K. z Lateral arch effect coefficient K x and the axial arching effect coefficient K y The calculation is performed, and the differences in dimensions and orders of magnitude between parameters are eliminated by the maximum value normalization method. The input is standardized to provide a unified input scale for subsequent arch effect calculations, thereby improving the stability and generalization of the calculation.

[0077] The data normalization unit performs dimensionless standardization on the raw collected values. The normalization calculation formula is as follows:

[0078] X = X(i,j,k) / X max ;

[0079] Where X is the original parameter, X max The maximum reference value for the construction area is set as follows:

[0080] density p max =2.6g / cm 3 ;

[0081] Moisture content ω max =20%;

[0082] Porosity n max =35%;

[0083] Dynamic modulus Cv max =200MPa;

[0084] static modulus Ch max =120MPa;

[0085] Formation friction coefficient Ca max =0.40;

[0086] The normalization results (i=3, j=2, k=5) are shown in Table 1 below:

[0087] Parameter (x) Original value Maximum value Normalized value density p 2.4 2.6 0.9231 Moisture content ω 12 20 0.60 Porosity n 28 35 0.80 Dynamic modulus Cv 180 200 0.90 static modulus Ch 95 120 0.7917 Formation friction coefficient Ca 0.36 0.4 0.90

[0088] Table 1

[0089] The arching effect analysis module is used to collect the arching effect behavior of the surrounding rock in the vertical, lateral, and axial directions using pressure sensors, and to calculate the vertical arching effect coefficient K. z Lateral arch effect coefficient K x With axial arch effect coefficient K yBased on normalized parameters, the vertical, lateral, and axial arch effect coefficients are calculated to achieve quantitative identification of the main and passive bearing paths of the surrounding rock.

[0090] The arch effect analysis module includes a vertical arch effect analysis unit, a lateral arch effect analysis unit, and an axial arch effect analysis unit. These units extract the evolution trend of the arch structure in each direction and calculate K based on the tension release situation. z K x K y The specific calculation formula is as follows:

[0091]

[0092] Wherein, η1, η2, η3, and η4 represent the degree of influence of different physical properties on the vertical arch effect; p max The maximum value of the surrounding rock density affects the magnitude of earth pressure; the higher the density, the greater the earth pressure. This value is used for normalization. ω max This represents the maximum water content of the surrounding rock, which affects the magnitude of earth pressure. Higher water content results in greater soil fluidity and deformation capacity, and is used for normalization treatment; n max This represents the maximum porosity of the surrounding rock. A higher porosity indicates lower soil density and lower earth pressure, and is used for normalization. (Cv) max The maximum value of the dynamic modulus of the surrounding rock reflects its elastic recovery ability after being subjected to stress. The larger the dynamic modulus, the smaller the deformation of the surrounding rock. It is used for normalization treatment; Ch max The static modulus of the surrounding rock is the maximum value, reflecting its deformation capacity under lateral loads. A larger static modulus indicates smaller rock deformation, and it is used for normalization. Ca max This represents the maximum value of the formation friction coefficient, which affects the magnitude of soil friction. The larger the friction coefficient, the greater the soil friction. It is used for normalization treatment.

[0093] In the above, if we set η1 = η2 = η3 = η4 = 0.25, then:

[0094] Vertical arch effect coefficient K z for:

[0095] Lateral arch effect coefficient K x for:

[0096] Axial arch effect coefficient K y for:

[0097] The three-dimensional earth pressure identification module is used to identify the vertical earth pressure, lateral earth pressure, and axial earth pressure based on the regional model (i,j,k) established in the data acquisition module.

[0098] The three-dimensional earth pressure recognition module includes a vertical earth pressure calculation unit, a lateral earth pressure calculation unit, and an axial earth pressure calculation unit.

[0099] The vertical earth pressure calculation unit is used to calculate the vertical earth pressure P. z The result is obtained through the following formula:

[0100] P z (i,j,k)=γ×H(i,j,k)×(1-K z (i,j,k));

[0101] The lateral earth pressure calculation unit is used to calculate the lateral earth pressure P. x The result is obtained through the following formula:

[0102] P x (i,j,k)=K a ×γ×H(i,j,k)×(1-K x (i,j,k));

[0103] The axial earth pressure calculation unit is used to calculate the axial earth pressure P. y The result is obtained through the following formula:

[0104] P y (i,j,k)=λ×γ×H(i,j,k)×(1-K y (i,j,k));

[0105] Where γ is the unit weight of the surrounding rock, λ is the axial adjustment coefficient, and K a Here, (i,j,k) represents the lateral pressure coefficient. 'i' represents the first spatial dimension index, i.e., the longitudinal position in the horizontal direction; 'j' represents the second spatial dimension index, i.e., the lateral position in the horizontal direction, used in conjunction with 'i' to represent the spatial distribution of the soil; and 'k' represents the third spatial dimension index, usually understood as the vertical position, i.e., the vertical distribution of the soil and the characteristics of the topsoil thickness. Therefore, (i,j,k) collectively represents a three-dimensional coordinate point in the soil space. The corresponding vertical earth pressure, lateral earth pressure, and axial earth pressure will be affected by physical parameters such as the topsoil thickness and soil pressure coefficient at position (i,j,k). Specifically: H(i,j,k): represents the topsoil thickness at this point, which varies with position; K... z (i,j,k),K x (i,j,k) and K y(i,j,k) represent the soil pressure coefficients in the vertical, lateral, and axial directions, respectively, and vary depending on the spatial location.

[0106] Based on the above data, let γ = 18 kN / m 3 Given a local soil thickness H(i,j,k) = 10m and λ = 0.7, then:

[0107] Vertical earth pressure P z =P z (i,j,k)=γ×H(i,j,k)×(1-K z (i,j,k))=18×10×(1-0.8308)=30.46kPa;

[0108] Lateral earth pressure P x =P x (i,j,k)=K a ×γ×H(i,j,k)×(1-K x (i,j,k))0.5×18×10×(1-0.8537)=13.57kPa;

[0109] Axial earth pressure P y =P y (i,j,k)=λ×γ×H(i,j,k)×(1-K y (i,j,k))==0.7×18×10×(1-0.8308)=21.32kPa;

[0110] The feedback control module is used to process the identified vertical earth pressure P. z Lateral earth pressure P x With axial earth pressure P y Each is compared with the design's basic threshold P. z0 P x0 With P y0 The difference ΔP was obtained by comparison. z ΔP x With ΔP y ;

[0111] The feedback control module includes a stress comparison unit;

[0112] The stress comparison unit is used to analyze the identified vertical earth pressure P. z Lateral earth pressure P x With axial earth pressure P y Each is compared with the design's basic threshold P. z0 P x0 With P y0 By performing comparative calculations, the vertical difference ΔP was obtained. z Lateral difference ΔP xaxial difference ΔP y As shown in the following formula:

[0113] ΔP z -P z -P z0 ;

[0114] ΔP x -P x -P x0 ;

[0115] ΔP y -P y -P y0 ;

[0116] Let P be the above. z0 =28.0 kPa, P x0 =12.5kPa, P y0 =20.0 kPa, then the difference is;

[0117] ΔP z =30.46 - 28.0 = 2.46 kPa;

[0118] The second settlement level is generated, representing the vertical difference ΔP. z There is a risk of subsidence; this area is marked in red.

[0119] ΔP x =13.57-12.5=1.07kPa;

[0120] Acceptable status; indicates lateral difference ΔP x The status is acceptable, marked as a green safe zone, and continuous monitoring is maintained without any operation required.

[0121] ΔP y =21.32-20.0=1.32kPa;

[0122] Then the axial difference ΔP y Located within the safe range, indicating the axial difference ΔP y The status is acceptable, marked as a green safe zone, and continuous monitoring is maintained without any operation required;

[0123] After generating the difference, this system can then use ΔP z ΔP x With ΔP y and set threshold P z0 P x0 With P y0 The comparisons are performed, and the results are output through the subsequent evaluation strategy unit.

[0124] The evaluation strategy module includes a decision mechanism unit and a strategy output unit;

[0125] The determination mechanism unit is used to determine the vertical difference ΔP. z Lateral difference ΔP x axial difference ΔP y The results are compared with the preset first judgment threshold Z1, second judgment threshold Z2, and third judgment threshold Z3, respectively, where the first judgment threshold Z1 is the vertical difference ΔP. z The safety threshold is set at Z1 = 1.5 kPa, and the risk levels are divided as follows:

[0126] When ΔP z When ≤1.5 kPa, the vertical difference ΔP z Located within the safe range, indicating vertical earth pressure P z The status is acceptable, marked as a green safe zone, and continuous monitoring is maintained without any operation required;

[0127] When 1.5 kPa ≤ ΔP z When ≤2.0 kPa, the vertical difference ΔP z Located in the warning zone, indicating vertical earth pressure P z There is a risk of settlement, and the first level of settlement has been generated, marked as a yellow area;

[0128] When ΔP z When the pressure is greater than 2.0 kPa, the vertical difference ΔP z Located in the danger zone, indicating vertical earth pressure P z There is a risk of settlement, and a second settlement level has been generated, marked as a red zone; the second settlement level is more dangerous than the first settlement level.

[0129] In the above, the green safety zone represents the area where the vertical earth pressure is within a safe range. Within this zone, the earth pressure value is less than or equal to 1.5 kPa, indicating that the vertical pressure on the soil is relatively light, the burden on the support structure is small, and the soil and support structure are in a relatively safe state under this pressure. Good stability can be maintained during the construction and operation of the project. The soil is stable within this zone and is not prone to excessive settlement or damage to the support structure. Construction personnel can continue to work normally without taking special measures immediately. During the construction process, earth pressure control is one of the key factors to ensure structural safety. The green safety zone not only means that the earth pressure is within a safe range, but also indicates that the coordination between the support structure and the surrounding rock is good during the project construction process, and there are no abnormal situations of excessive or insufficient pressure. Within this zone, the deformation and settlement of the support structure are small, and the construction team can complete the task relatively easily. In addition, the green safety zone is also the ideal state of the project in multiple construction stages.

[0130] The yellow warning zone indicates that the soil pressure is approaching the safety threshold and has entered a warning state. Vertical soil pressure values ​​are between 1.5 kPa and 2.0 kPa, meaning the soil's bearing pressure is close to or slightly exceeds the design safety value. The support structure faces a certain pressure burden, which may lead to slight deformation or settlement of the surrounding rock or support structure. Construction units need to pay close attention to changes in soil pressure, take necessary monitoring measures, and prepare early warning responses to prevent further increases in soil pressure. The yellow warning zone indicates a high level of vertical soil pressure, indicating a warning state. Although the soil pressure value in this zone has not reached the danger threshold, its gradually increasing trend reminds engineers that they may face greater risks. The soil pressure in this zone is usually not caused by sudden problems triggered by geological disasters, but rather by pressure accumulation due to improper operation or design problems during construction. In this zone, the support structure usually exhibits minor displacement or deformation, but this may not have a serious impact on structural stability. To prevent the soil pressure from continuing to rise, the construction team should strengthen monitoring, especially paying close attention to the soil, surrounding rock, and support structure.

[0131] The red danger zone indicates that the vertical earth pressure has exceeded the design safety threshold, entering a dangerous state. This means that the soil is under extremely high pressure, and the support structure and surrounding rock are facing enormous pressure loads, significantly increasing the risk of collapse, deformation, or failure. At this time, construction personnel must immediately take emergency measures to ensure personnel safety and project stability. In the red danger zone, the earth pressure significantly exceeds the design value, which may cause serious safety hazards. The support structure may undergo extreme deformation, leading to loss of structural function, and in severe cases, even collapse or landslide. At this time, the stability of the surrounding rock is seriously threatened, which may lead to large-scale soil deformation or fracture. Within this zone, the construction team must immediately stop construction and carry out emergency response, taking strong support measures to reduce the risk of accidents.

[0132] The second judgment threshold Z2 is the lateral difference ΔP x The safety threshold, lateral difference ΔP x This will affect the lateral stability of the support structure and should be avoided from exceeding the standard range. A safety threshold of Z2 = 2.0 kPa is set, and the risk level is classified as follows:

[0133] When ΔP x When ≤1.5 kPa, the lateral difference ΔP x Located within the safe range, indicating lateral earth pressure P x The status is acceptable, marked as a green safe zone, and continuous monitoring is maintained without any operation required;

[0134] When 1.5 kPa ≤ ΔP x When ≤2.0 kPa, the lateral difference ΔP x Located in the warning zone, indicating lateral earth pressure Px There is a risk of lateral deformation of the support structure, and the first level of support deformation risk is generated, marked as a yellow zone;

[0135] When ΔP x When the pressure is greater than 2.0 kPa, the lateral difference ΔP x Located in the danger zone, indicating lateral earth pressure P x There is a risk of lateral deformation of the support structure, and a support deformation risk level is generated, marked as a red zone; the second support deformation risk level is more dangerous than the first support deformation risk level.

[0136] The green safety zone indicates that the lateral earth pressure is within the design standard safety range. Within this zone, the lateral earth pressure value of the soil does not exceed 2.0 kPa, the lateral stability of the support structure is relatively strong, and the pressure borne by the soil has little impact on the support structure. At this time, the design and construction of the support structure can meet the requirements of the earth pressure, the project is in a stable state, the deformation of the soil and the support structure is within a controllable range, and there are no obvious safety hazards. The green safety zone indicates that the maximum lateral earth pressure that the support structure can withstand has not been reached, and the stress state of the structure remains within the predetermined design range. Within this zone, the lateral deformation of the support structure is relatively small, the stability of the structure is good, and it can effectively prevent uneven settlement or excessive deformation of the soil. The green zone is the ideal state of the support structure design and also the normal operating state in the implementation of the project. Within this zone, the support structure will not be affected by excessive lateral pressure, so the construction party can proceed with the next step of the work with peace of mind.

[0137] The yellow warning zone indicates that the lateral earth pressure has approached or slightly exceeded the safety threshold. The lateral pressure of the soil on the support structure has begun to increase, and the stability of the support structure faces certain challenges. At this time, the deformation and displacement of the support structure are still within a controllable range, but continuing to exceed this zone may cause structural instability and other potential risks. Therefore, within the yellow warning zone, the construction and operation parties should strengthen monitoring and take certain preventive measures to avoid further increase in earth pressure. In the yellow warning zone, the earth pressure has approached the design safety threshold, and the stress state of the support structure has begun to enter the warning state. Although the current earth pressure has not yet reached a dangerous level, if measures are not taken in time, the earth pressure may continue to increase, causing uneven deformation or damage to the support structure. At this time, the lateral stability of the support structure is threatened to a certain extent, which may lead to slight settlement or deformation of the foundation pit slope, tunnel wall or other underground structures. The project party needs to closely monitor the changes in earth pressure in this zone and take effective monitoring and reinforcement measures to avoid further increase in risk.

[0138] The red danger zone indicates that the lateral earth pressure has exceeded the design safety threshold and entered an extremely dangerous state. At this time, the lateral pressure exerted by the soil poses a serious threat to the lateral stability of the support structure. The support structure may experience extreme deformation, damage, or collapse. If the lateral earth pressure enters the red danger zone during construction, construction must be stopped immediately, emergency reinforcement measures must be taken, and the overall safety of the project must be assessed. In the red danger zone, the earth pressure value exceeds the design bearing limit, and the support structure may face extreme lateral deformation or even structural damage. The risk in this zone is extremely high, and any improper operation may lead to severe soil deformation or collapse of the support structure. Construction and operation units must pay close attention to this situation and immediately take emergency measures such as reinforcing the support structure and adjusting the construction plan to prevent further damage caused by earth pressure.

[0139] The third judgment threshold Z3 is the axial difference ΔP. y Safety threshold, axial difference ΔP y The axial pressure should be controlled within a suitable range to avoid local instability of the support structure caused by excessive axial pressure. A safety threshold of Z3 = 2.5 kPa is set, and the risk level is classified as follows:

[0140] When ΔP y When ≤1.5 kPa, the axial difference ΔP y Located within the safe range, indicating axial earth pressure P y The status is acceptable, marked as a green safe zone, and continuous monitoring is maintained without any operation required;

[0141] When 1.5 kPa ≤ ΔP y When ≤2.0 kPa, the axial difference ΔP y Located in the warning zone, indicating axial earth pressure P y There is a risk of shear cracking, and the first shear cracking risk level is generated, marked as a yellow zone;

[0142] When ΔP y When the pressure is greater than 2.0 kPa, the axial difference ΔP y Located in the danger zone, indicating axial earth pressure P y There is a risk of shear cracking, and a second shear cracking risk level is generated, marked as a red zone. The first shear cracking risk level is more dangerous than the first shear cracking risk level.

[0143] The green safety zone indicates that the axial earth pressure is within the design safety threshold and is within a normal and safe range. At this time, the impact of the axial pressure applied by the soil on the support structure is controllable. The support structure remains within the design range and will not cause local instability, settlement or structural damage due to excessive axial earth pressure. The earth pressure level in this zone will not threaten the stability of the project. The interaction between the soil and the support structure is in a state of equilibrium. Within the green safety zone, the support structure can withstand the axial pressure applied by the soil, and the earth pressure is within the predetermined safety range. At this time, the structural design goal is achieved, and the deformation, settlement and stability of the support structure are all in a safe state.

[0144] The yellow warning zone indicates that the axial earth pressure has approached the safety threshold and exceeded the green safety zone, but has not yet reached the red danger zone. At this time, the support structure may be subjected to large axial pressure. If no effective measures are taken, the pressure exerted by the soil may further increase, leading to structural instability. Although the impact of the axial pressure exerted by the soil on the structure is still within a controllable range within the yellow warning zone, if it continues to increase, it may threaten the stability of the support structure. In the yellow warning zone, although the axial pressure exerted by the soil has not yet reached the danger level, it has approached or exceeded the design limit of the support structure. If it continues to increase, it may cause local deformation or instability of the structure. At this time, the support structure should strengthen the monitoring and management of the axial pressure of the soil to avoid the soil pressure from continuing to increase.

[0145] The red danger zone indicates that the axial earth pressure has exceeded the design safety threshold, entering an extremely dangerous state. Within this zone, the axial pressure on the support structure far exceeds its design capacity, and the stability and safety of the structure are seriously threatened. The support structure may experience local instability, excessive settlement, deformation, or damage, which could lead to engineering accidents in severe cases. At this time, the construction and operation units must take emergency measures to alleviate the earth pressure and prevent catastrophic accidents. Within the red danger zone, the stability and safety of the support structure are extremely fragile. Excessive axial earth pressure may cause damage to the support structure, which may experience local deformation or damage, or even lead to the instability of the entire structure. The construction or operation parties should immediately take emergency reinforcement and repair measures to prevent larger-scale damage.

[0146] In the above, when the difference in earth pressure in any area exceeds the corresponding threshold, the system will trigger a risk alarm and generate an early warning strategy.

[0147] The determination mechanism unit can also be used to comprehensively judge the stability of the surrounding rock by combining the changes in earth pressure with the actual deformation of the support structure, as follows:

[0148] Safety condition: When the vertical difference ΔP z Lateral difference ΔPx axial difference ΔP y When all three are within the green safety zone, it indicates that the surrounding rock is stable;

[0149] Warning status: When the vertical difference ΔP z Lateral difference ΔP x axial difference ΔP y If any item appears in the yellow zone, the system will output the first alarm warning, indicating that there is a risk of rock collapse in the surrounding rock.

[0150] Critical situation: When the vertical difference ΔP z Lateral difference ΔP x axial difference ΔP y If any item appears in the red zone, the system will output a second alarm warning, indicating that the stability of the surrounding rock is more serious than in the warning state;

[0151] In the first alarm warning state, the system will generate an adjustment strategy to increase the thickness of the sprayed layer by 23cm in terms of vertical, lateral and axial earth pressure. In the second alarm warning state, the system will generate an adjustment strategy to increase the thickness of the sprayed layer by 53cm in terms of vertical, lateral and axial earth pressure.

[0152] The strategy output unit is used to automatically trigger different response strategies based on different thresholds:

[0153] Under safe conditions, the change in earth pressure is within a safe range, the surrounding rock is stable, the support structure is normal, and the existing support design and construction plan can be maintained without any adjustments.

[0154] Based on the first alarm warning, a first strategy is generated, including: setting up temporary support and temporary bracing measures in local areas, specifically reducing the anchor bolt spacing from 1.5m×1.5m to 0.9m×1.0m;

[0155] Based on the second alarm warning, a second strategy is generated, including: immediately activating the emergency reinforcement plan, adding more anchor bolts, suspending construction in the danger zone, initiating evacuation procedures, ensuring the safety of construction personnel, and conducting a detailed stability analysis based on soil pressure changes and surrounding rock deformation data to determine an emergency response plan, specifically reducing the anchor bolt spacing from 0.9m×1.0m to 0.5m×0.8m.

[0156] Specifically, the working process or principle of the three-dimensional earth pressure intelligent feedback system for the surrounding rock-support system of the shallow-buried ultra-large cross-section tunnel station is as follows: First, the parameter acquisition unit acquires key physical and mechanical parameters of the surrounding rock in real time through high-precision ground-penetrating radar, laser scanning equipment, and core sample collection devices deployed at different locations in the station's surrounding rock. These parameters mainly include: density p, water content ω, porosity n, dynamic modulus Cv, static modulus Ch, and stratum friction coefficient Ca. To ensure the representativeness and accuracy of the data, the acquisition of each parameter is based on the spatial zoning principle of tunnel engineering. Three-dimensional spatial index coordinates (i,j,k) are used to locate each measurement unit to ensure that the data covers the entire surrounding rock area. Then, the surrounding rock zoning modeling unit divides the entire station's surrounding rock into multiple spatial cells according to the tunnel's longitudinal excavation direction (i), cross-sectional direction (j), and vertical burial depth (k). Each cell corresponds to a set of parameter acquisition points, enabling the spatial modeling to have high-resolution physical continuity and mechanical response consistency. This 3D indexing system not only supports region-by-region calculation and analysis, but also provides a positioning framework for multi-source data fusion and visualization rendering. Subsequently, the data normalization unit performs dimensionless processing on the collected parameters. Since different physical quantities have different dimensions and orders of magnitude, in order to eliminate the bias they bring to the calculation model, the system uses the maximum value normalization method to map various data into intervals, ensuring the accuracy of subsequent calculations of the triaxial arch effect coefficient.

[0157] The vertical arch effect calculation unit, based on the gravity effect of the overburden load, assesses whether an effective stress-sharing structure is formed at the top of the surrounding rock under the conditions of the surrounding rock's self-weight and construction disturbance. When the vertical arch effect is strong, it means that part of the overburden load travels downstream through both sides of the arch, thereby reducing the direct bearing pressure on the top plate. The lateral arch effect calculation unit focuses on whether the surrounding rock on both sides of the tunnel produces a lateral stress arc-shaped transmission phenomenon in the presence of the initial support. Especially under conditions of joint development or uneven ground stress, there may be different reaction force absorption and shear structure stability paths on the left and right sides of the surrounding rock. The axial arch effect calculation unit is used to determine the release and redistribution of stress in the surrounding rock along the longitudinal direction of tunnel advancement (i.e., the construction step direction). Especially during segmented excavation and multi-step excavation, there is a phenomenon of mutual unloading and alternating tension and compression between axial surrounding rocks. The three-dimensional earth pressure intelligent feedback system for the surrounding rock-support system of shallow buried ultra-large cross-section tunnel stations provided by this invention aims to build an engineering intelligent perception and feedback platform with arch effect identification as the core, earth pressure dynamic evolution as the main line, and risk zoning control as the goal.

[0158] It should be noted that all calculation formulas in this application employ, but are not limited to, regression analysis from machine learning algorithms to deeply analyze the collected parameters and identify their natural trends and interrelationships. Specialized software, such as Python's Scikit-learn library or the R language, is used to automatically generate mathematical models that match the data. Then, cross-validation and other methods are used to objectively evaluate the model performance, and continuous feedback and optimization are combined to ensure that the created formulas truly reflect the inherent laws of the data, thereby guaranteeing their validity and accuracy, and ensuring that the calculation process conforms to the constraints of natural laws, rather than being based on artificially set rules.

[0159] The technical solution of this invention, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as a computer floppy disk, read-only memory (ROM), random access memory (RAM), flash memory, hard disk, or optical disk, etc., including several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods of the various embodiments of this invention.

[0160] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device.

[0161] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

[0162] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A three-dimensional intelligent earth pressure feedback system for the surrounding rock-support system of a shallow-buried, ultra-large cross-section tunnel railway station, characterized in that: It includes a data acquisition module, an arch effect analysis module, a three-dimensional earth pressure identification module, a feedback control module, and an evaluation strategy module; The data acquisition module is used to collect basic parameters of the surrounding rock, including: density p, water content ω, porosity n, dynamic modulus Cv, static modulus Ch and formation friction coefficient Ca, and to establish three-dimensional spatial index coordinates (i,j,k) to realize regional modeling, and to calibrate the data of the regional model (i,j,k). The arching effect analysis module is used to collect the arching effect behavior of the surrounding rock in the vertical, lateral, and axial directions using pressure sensors, and to calculate the vertical arching effect coefficient K. z Lateral arch effect coefficient K x With axial arch effect coefficient K y ; The three-dimensional earth pressure identification module is used to identify the vertical earth pressure, lateral earth pressure, and axial earth pressure based on the regional model (i,j,k) established in the data acquisition module. The feedback control module is used to process the identified vertical earth pressure P. z Lateral earth pressure P x With axial earth pressure P y Each is compared with the design's basic threshold P. z0 P x0 With P y0 The difference ΔP was obtained by comparison. z ΔP x With ΔP y ; The evaluation strategy module is used to set judgment thresholds: a first judgment threshold Z1, a second judgment threshold Z2, and a third judgment threshold Z3, and to combine ΔP z ΔP x With ΔP y Comparisons are made to provide early warnings and response strategies.

2. The three-dimensional earth pressure intelligent feedback system for the surrounding rock-support system of a shallow-buried, ultra-large cross-section tunnel railway station as described in claim 1, is characterized in that... The data acquisition module includes a parameter acquisition unit, a surrounding rock zoning modeling unit, and a data normalization unit. The parameter acquisition unit extracts the density p, water content ω, porosity n, dynamic modulus Cv, static modulus Ch and formation friction coefficient Ca from the surrounding rock through ground radar, laser scanner and core analysis. The partitioned modeling unit divides the surrounding rock into regions (i,j,k) for modeling and establishes a coordinate grid. The data normalization unit is used to perform dimensionless processing on density p, water content ω, porosity n, dynamic modulus Cv, static modulus Ch, and formation friction coefficient Ca, which facilitates the calculation of the vertical arching effect coefficient K. z Lateral arch effect coefficient K x and the axial arching effect coefficient K y Perform the calculation.

3. The three-dimensional earth pressure intelligent feedback system for the surrounding rock-support system of a shallow-buried, ultra-large cross-section tunnel railway station as described in claim 2, is characterized in that... The arch effect analysis module includes a vertical arch effect analysis unit, a lateral arch effect analysis unit, and an axial arch effect analysis unit. These units extract the evolution trend of the arch structure in each direction and calculate K based on the tension release situation. z K x K y .

4. The three-dimensional earth pressure intelligent feedback system for the surrounding rock-support system of a shallow-buried, ultra-large cross-section tunnel railway station according to claim 3, is characterized in that, The three-dimensional earth pressure recognition module includes a vertical earth pressure calculation unit, a lateral earth pressure calculation unit, and an axial earth pressure calculation unit. The vertical earth pressure calculation unit is used to calculate the vertical earth pressure P. z ; The lateral earth pressure calculation unit is used to calculate the lateral earth pressure P. x ; The axial earth pressure calculation unit is used to calculate the axial earth pressure P. y .

5. The three-dimensional earth pressure intelligent feedback system for the surrounding rock-support system of a shallow-buried, ultra-large cross-section tunnel railway station according to claim 4, is characterized in that, The feedback control module includes a stress comparison unit; The stress comparison unit is used to analyze the identified vertical earth pressure P. z Lateral earth pressure P x With axial earth pressure P y Each is compared with the design's basic threshold P. z0 P x0 With P y0 By performing comparative calculations, the vertical difference ΔP was obtained. z Lateral difference ΔP x axial difference ΔP y .

6. The three-dimensional earth pressure intelligent feedback system for the surrounding rock-support system of a shallow-buried, ultra-large cross-section tunnel railway station according to claim 5, is characterized in that, The evaluation strategy module includes a decision mechanism unit and a strategy output unit; The determination mechanism unit is used to determine the vertical difference ΔP. z Lateral difference ΔP x axial difference ΔP y The results are compared with the preset first judgment threshold Z1, second judgment threshold Z2, and third judgment threshold Z3, respectively, where the first judgment threshold Z1 is the vertical difference ΔP. z The safety threshold is set at Z1 = 1.5 kPa, and the risk levels are divided as follows: When ΔP z When ≤1.5 kPa, the vertical difference ΔP z Located within the safe range, indicating vertical earth pressure P z The status is acceptable, marked as a green safe zone, and continuous monitoring is maintained without any operation required; When 1.5 kPa ≤ ΔP z When ≤2.0 kPa, the vertical difference ΔP z Located in the warning zone, indicating vertical earth pressure P z There is a risk of settlement, and the first level of settlement has been generated, marked as a yellow area; When ΔP z When the pressure is greater than 2.0 kPa, the vertical difference ΔP z Located in the danger zone, indicating vertical earth pressure P z There is a risk of settlement, and a second settlement level has been generated, marked as a red zone; the second settlement level is more dangerous than the first settlement level.

7. The three-dimensional earth pressure intelligent feedback system for the surrounding rock-support system of a shallow-buried, ultra-large cross-section tunnel railway station according to claim 6, is characterized in that, The second judgment threshold Z2 is the lateral difference ΔP x The safety threshold, lateral difference ΔP x This will affect the lateral stability of the support structure and should be avoided from exceeding the standard range. A safety threshold of Z2 = 2.0 kPa is set, and the risk level is classified as follows: When ΔP x When ≤1.5 kPa, the lateral difference ΔP x Located within the safe range, indicating lateral earth pressure P x The status is acceptable, marked as a green safe zone, and continuous monitoring is maintained without any operation required; When 1.5 kPa ≤ ΔP x When ≤2.0 kPa, the lateral difference ΔP x Located in the warning zone, indicating lateral earth pressure P x There is a risk of lateral deformation of the support structure, and the first level of support deformation risk is generated, marked as a yellow zone; When ΔP x When the pressure is greater than 2.0 kPa, the lateral difference ΔP x Located in the danger zone, indicating lateral earth pressure P x There is a risk of lateral deformation of the support structure, and a support deformation risk level is generated, marked as a red zone; The second support deformation risk level is more dangerous than the first support deformation risk level.

8. The three-dimensional earth pressure intelligent feedback system for the surrounding rock-support system of a shallow-buried, ultra-large cross-section tunnel railway station according to claim 7, is characterized in that, The third judgment threshold Z3 is the axial difference ΔP. y Safety threshold, axial difference ΔP y The axial pressure should be controlled within a suitable range to avoid local instability of the support structure caused by excessive axial pressure. A safety threshold of Z3 = 2.5 kPa is set, and the risk level is classified as follows: When ΔP y When ≤1.5 kPa, the axial difference ΔP y Located within the safe range, indicating axial earth pressure P y The status is acceptable, marked as a green safe zone, and continuous monitoring is maintained without any operation required; When 1.5 kPa ≤ ΔP y When ≤2.0 kPa, the axial difference ΔP y Located in the warning zone, indicating axial earth pressure P y There is a risk of shear cracking, and the first shear cracking risk level is generated, marked as a yellow zone; When ΔP y When the pressure is greater than 2.0 kPa, the axial difference ΔP y Located in the danger zone, indicating axial earth pressure P y There is a risk of shear cracking, and a second shear cracking risk level is generated, marked as a red zone. The first shear cracking risk level is more dangerous than the first shear cracking risk level. In the above, when the difference in earth pressure in any area exceeds the corresponding threshold, the system will trigger a risk alarm and generate an early warning strategy.

9. The three-dimensional earth pressure intelligent feedback system for the surrounding rock-support system of a shallow-buried, ultra-large cross-section tunnel railway station according to claim 8, is characterized in that, The determination mechanism unit can also be used to comprehensively judge the stability of the surrounding rock by combining the changes in earth pressure with the actual deformation of the support structure, as follows: Safety condition: When the vertical difference ΔP z Lateral difference ΔP x axial difference ΔP y When all three are within the green safety zone, it indicates that the surrounding rock is stable; Warning status: When the vertical difference ΔP z Lateral difference ΔP x axial difference ΔP y If any item appears in the yellow zone, the system will output the first alarm warning, indicating that there is a risk of rock collapse in the surrounding rock. Critical situation: When the vertical difference ΔP z Lateral difference ΔP x axial difference ΔP y If any item appears in the red zone, the system will output a second alarm warning, indicating that the stability of the surrounding rock is more serious than in the warning state; In the first alarm warning state, the system will generate an adjustment strategy to increase the thickness of the sprayed layer by 23cm in terms of vertical, lateral and axial earth pressure. In the second alarm warning state, the system will generate an adjustment strategy to increase the thickness of the sprayed layer by 53cm in terms of vertical, lateral and axial earth pressure.

10. The three-dimensional earth pressure intelligent feedback system for the surrounding rock-support system of a shallow-buried, ultra-large cross-section tunnel railway station according to claim 9, is characterized in that, The strategy output unit is used to automatically trigger different response strategies based on different thresholds: Under safe conditions, the change in earth pressure is within a safe range, the surrounding rock is stable, the support structure is normal, and the existing support design and construction plan can be maintained without any adjustments. Based on the first alarm warning, a first strategy is generated, including: setting up temporary support and temporary bracing measures in local areas, specifically reducing the anchor bolt spacing from 1.5m×1.5m to 0.9m×1.0m; Based on the second alarm warning, a second strategy is generated, including: immediately activating the emergency reinforcement plan, adding more anchor bolts, suspending construction in the danger zone, initiating evacuation procedures, ensuring the safety of construction personnel, and conducting a detailed stability analysis based on soil pressure changes and surrounding rock deformation data to determine an emergency response plan, specifically reducing the anchor bolt spacing from 0.9m×1.0m to 0.5m×0.8m.

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