A method for controlling ground stress during subway expansion and construction

Abstract

The present invention relates to the technical field of subway double-sided expansion technology. A method for controlling ground stress for subway expansion deformation includes the following steps: obtaining geological data of the subway expansion site, and constructing an excavation stress model using the geological data; obtaining a stress change report of the stress release zone under the construction process using the excavation stress model; obtaining ground stress release information based on the stress change report and the characteristic data of the plastic body; obtaining real-time ground stress data of the stress release zone under the construction process and simulated ground stress data corresponding to the excavation stress model, and comparing the real-time ground stress data with the simulated ground stress data to obtain ground stress release correction information. This system deeply integrates high-precision geological data acquisition, dynamic finite element modeling, and intelligent real-time control to construct a closed-loop ground stress control system. It realizes the full-process innovation of accurate prediction-dynamic control-resource optimization, and provides a safe and efficient technical model for subway expansion in densely populated urban areas.

Description

Technical Field

[0001] The present invention relates to the technical field of subway double-sided extension construction, and in particular to a method for controlling ground stress during subway extension construction deformation. Background Art

[0002] With the acceleration of urbanization, demand for subways as efficient urban transportation solutions is increasing. However, during subway tunnel construction, especially in double-sided excavation, ground disturbances caused by excavation and the redistribution of longitudinal geostress can adversely affect subway structures, leading to phenomena such as subway vibration and train jumping, seriously compromising ride comfort and safety.

[0003] Furthermore, long-term geostress can cause permanent deformation of subway structures, threatening passenger safety and increasing maintenance costs. Traditional construction solutions address these issues by reinforcing tunnel linings, optimizing excavation methods, or installing seismic isolation devices. However, these methods often fail to effectively mitigate the impact of geostress on surrounding commercial complexes and may increase project complexity and costs. Summary of the Invention

[0004] The purpose of the present invention is to provide a ground stress control system for subway expansion and construction to solve the problem of the lack of intelligence of the existing financial system in the survey and design industry.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solution: a method for controlling ground stress during subway expansion and construction deformation, comprising the following steps:

[0006] Step 1: Obtain geological data of the subway expansion site and use it to construct an excavation stress model;

[0007] Step 2: Use the excavation stress model to obtain the stress change report of the stress release zone under the construction process;

[0008] Step 3: Obtain ground stress release information based on the stress change report and the characteristic data of the plastic body;

[0009] Step 4: Obtain the real-time ground stress data of the stress release zone under the construction process and the simulated ground stress data corresponding to the excavation stress model, and compare the real-time ground stress data with the simulated ground stress data to obtain ground stress release correction information.

[0010] Furthermore, the acquisition of geological data at the subway expansion site and the construction of an excavation stress model using the geological data include the following steps:

[0011] Step 11: Use the soil layer information and groundwater information obtained from the subway construction site survey as geological data;

[0012] Step 12: Construct an initial stress model using geological data based on finite element analysis;

[0013] Step 13: Set the stress release area in the initial stress model to obtain the excavation stress model;

[0014] in,

[0015] The soil layer information includes soil layer type, soil layer thickness, soil layer distribution and mechanical parameters;

[0016] The mechanical parameters include soil density, soil internal friction angle, and soil cohesion;

[0017] The groundwater information includes groundwater level, groundwater flow data and groundwater pressure;

[0018] The stress release zone is a width band 5-10m away from the subway.

[0019] Furthermore, the excavation stress model is expressed by the formula:

[0020] Express;

[0021] in, is the excavation stress, which represents the stress distribution at a horizontal distance x from the excavation surface at time t; is the excavation depth at time t;

[0022] is the weight of balancing soil layer information in the entire stress model; L is the soil layer action value;

[0023] To balance the weight of groundwater information in the entire stress model; W is the groundwater action value;

[0024] To balance the weight of plastic body stress in the entire stress model; is the plastic body stress, which represents the excavation depth at time t and the stress distribution function of the plastic body at the horizontal distance x;

[0025] Specifically,

[0026] in, is the coefficient of soil type of layer i; n is the number of soil layers; is the thickness of the i-th soil layer; is the soil density of the i-th layer; is the internal friction angle of the i-th layer of soil; is the soil cohesion of the i-th layer;

[0027] ;in, is the groundwater level influence coefficient; is the influence coefficient of groundwater flow direction, is the flow rate, is the flow angle; is the groundwater pressure influence coefficient, and the calculation formula is: , It is the weight of water.

[0028] in, is the stress response coefficient of the plastic body; is the excavation depth at time t and the stress distribution function at the horizontal distance x; is the influence function of the stress release zone, indicating whether the horizontal distance x from the excavation surface is in the stress release zone at time t; specifically,

[0029] , where k1, k2 and k3 are adjustment coefficients, representing the effects of excavation depth, excavation speed and horizontal distance on stress distribution respectively; H is the total excavation depth; is the excavation speed; x s is the centerline position of the stress relief zone; q is the width of the stress relief zone;

[0030] like , otherwise 0.

[0031] Furthermore, the method of obtaining a stress change report of a stress release zone during a construction process using an excavation stress model includes the following steps:

[0032] Step 21: Simulate different time points of the construction process in the excavation stress model to obtain construction stress distribution information at different time points in the stress release zone;

[0033] Step 22: Fitting the construction stress distribution information at different time points to obtain a fitting stress report of the stress release area;

[0034] Step 23: Determine whether there is a stress value exceeding the control threshold in the fitting stress report. If so, optimize the construction plan; otherwise, use the fitting stress report as a stress change report.

[0035] Furthermore, the layout position of the plastic body is the area where the ground uplift amount in the stress release area is greater than the uplift threshold in the construction stress distribution information. , k is the elastic coefficient of the stress release zone, is the stress value difference between two construction times at a certain point.

[0036] Furthermore, the fitting of the construction stress distribution information at different time points to obtain the fitting stress report of the stress release zone includes the following steps:

[0037] Step 221: extracting construction stress distribution data at multiple discrete time points in the construction process and verifying its integrity;

[0038] Step 222: Based on the nonlinear characteristics of the time interval and stress distribution, a cubic spline interpolation method is selected, whose interpolation function satisfies the second-order continuous and differentiable boundary conditions, to establish a time-stress distribution model;

[0039] Step 223: interpolating and generating a stress distribution curve of a continuous time series according to the time-stress distribution model, and extracting the interpolated stress value at each horizontal distance in the stress release area;

[0040] Step 224: constructing a dynamic stress cloud map of the stress release area based on the interpolated stress value, and marking the maximum stress value and its corresponding position and time node;

[0041] Step 225: Compare the dynamic stress cloud map with the simulated ground stress data of the excavation stress model to generate a fitting stress report including a stress deviation analysis;

[0042] Step 226: If the deviation between the interpolated stress value and the simulated in-situ stress data exceeds a preset tolerance threshold, reselect the interpolation method or adjust the interpolation parameters and repeat steps 223 to 225 until the deviation meets the preset tolerance threshold.

[0043] Furthermore, the obtaining of ground stress release information based on the stress change report and the characteristic data of the plastic body includes the following steps:

[0044] Step 31: Obtain the continuous stress distribution data of the stress release zone from the stress change report, and calculate the release strength of all plastic bodies at each time node;

[0045] Step 32: Determine whether the release strength of the plastic body obtained in step 31 will cause a bulge in the stress release area. If so, compensate for the release strength of the plastic body adjacent to the bulge and execute step 32 again. Otherwise, execute step 33.

[0046] Step 33: Fit the release strength of the same plastic body at all time points, and use the fitted release strength and the layout position of the plastic body as the ground stress release information.

[0047] The beneficial effects of this invention are as follows: This system deeply integrates high-precision geological data acquisition, dynamic finite element modeling, and intelligent real-time control to construct a closed-loop geostress control system. This system achieves a comprehensive process innovation from precise prediction to dynamic control to resource optimization, providing a safe and efficient technical model for subway expansion in densely populated urban areas.

[0048] By introducing deformable materials near subway tunnels, the longitudinal ground stress caused by excavation is effectively absorbed and released, greatly reducing the external force on the subway structure, thereby significantly reducing the risk of subway deformation and improving riding comfort and safety.

[0049] Compared with traditional reinforcement measures, the present invention provides a more flexible and economical solution, reduces unnecessary construction steps and material usage, shortens construction period and reduces overall cost.

[0050] Combining modern sensing technology and data analysis, the present invention realizes real-time monitoring and automatic regulation of ground stress, making the entire system more intelligent, able to quickly respond to environmental changes, and ensuring the long-term effectiveness of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 Flowchart of the ground stress regulation method for deformation control in subway expansion. DETAILED DESCRIPTION

[0052] The following will be combined with the accompanying drawings to clarify the technical solutions in the embodiments of the present invention; although it is clear that the embodiments described are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0053] In Example 1, a section expansion project on Tianjin Metro Line 6 was constructed. This project required the construction of a commercial complex on both sides of the existing subway line. The construction area faced complex geological conditions, including soft clay layers, sand layers, and areas with high groundwater levels. To ensure construction safety and prevent damage to surrounding buildings from ground subsidence or uplift, this system was used to dynamically control ground stress.

[0054] like Figure 1 As shown, a method for controlling ground stress during subway expansion and construction deformation includes the following steps:

[0055] Step 1: Obtain geological data for the subway expansion site and use it to construct an excavation stress model. The geological data is provided by the surveying and mapping agency. Before using it to construct the excavation stress model, data cleaning is required to ensure model accuracy. Based on this geological data, finite element analysis software is used to simulate the stress distribution at different excavation stages. This process not only considers the effects of static loads but also provides an accurate distribution map of the geostress field, helping to identify potential risk areas and providing a scientific basis for subsequent construction planning, reducing blindness.

[0056] Step 2: Use the excavation stress model to obtain a stress change report for the stress release zone during the construction process. After completing the excavation stress model, further simulation of the specific construction process is required, such as segmented excavation and support structure installation. After each process is completed, a corresponding stress change report is generated. These reports typically include information such as trend graphs of stress changes over time and maximum and minimum stress values ​​at key points. In this way, changes in ground stress during construction can be intuitively observed, providing feedback on changes in ground stress during construction and facilitating timely adjustments to construction strategies.

[0057] Step 3: Obtain geostress release information based on the stress change report and plastomer characteristic data. Plastomers refer to hydraulic expansion devices, such as bladder grouting devices. Combined with the data from the stress change report, the stress release of each plastomer over the entire construction cycle is calculated to assess the overall geostress release status. Plastomers enhance the geostress release mechanism's ability to mitigate heave risks, ensuring effective management and control of geostress during construction.

[0058] Step 4: Obtain real-time geostress data for the stress release zone during the construction process and simulated geostress data corresponding to the excavation stress model. Compare the real-time and simulated geostress data to obtain geostress release correction information. A sensor network is deployed at the construction site to continuously monitor changes in geostress. These sensors provide a continuous data stream for subsequent analysis. Real-time geostress data is compared with previous simulation results to identify discrepancies and adjust model parameters accordingly to improve prediction accuracy. This creates a closed-loop feedback mechanism between theoretical predictions and actual observations, enhancing model accuracy. This allows the engineering team to detect deviations immediately and respond quickly, ensuring construction safety and efficiency.

[0059] In summary, this system deeply integrates high-precision geological data acquisition, dynamic finite element modeling, and intelligent real-time control to build a closed-loop geostress control system. This system revolutionizes the entire process from precise prediction to dynamic control to resource optimization, providing a safe and efficient technical model for subway expansion in densely populated urban areas.

[0060] Obtaining geological data for the subway expansion site and using it to construct an excavation stress model involves the following steps:

[0061] Step 11: Soil and groundwater information obtained from surveys of subway construction sites was used as geological data. Soil information includes soil type, thickness, distribution, and mechanical parameters; mechanical parameters include soil density, internal friction angle, and cohesion; and groundwater information includes groundwater level, groundwater flow data, and groundwater pressure. Tianjin is located in the alluvial belt of the North China Plain. Its geology is primarily characterized by interbedded layers of soft clay and fine silt, with a prominent high groundwater level and highly permeable sand layers. Groundwater information primarily influences the model's effects on pore water pressure dominating effective stress, permeability-induced sand liquefaction risk, salinization affecting soil mechanical parameters, and dynamic water level fluctuations triggering model iterations. During construction, due to neglecting the coupling effect between groundwater flow direction and sand permeability, the initial model predicted a settlement of 1.2 mm, while the measured value reached 2.0 mm. After supplementing with groundwater data, the revised model's secondary prediction was 1.9 mm, with an error of only 5%.

[0062] Step 12: Construct an initial stress model using geological data based on finite element analysis;

[0063] Step 13: Set the stress release area in the initial stress model to obtain the excavation stress model;

[0064] Among them, the stress release zone is a width band of 5-10m away from the subway.

[0065] The excavation stress model achieves refined prediction and control of ground stress in subway expansion projects under complex geological conditions through multi-factor coupling, dynamic weight allocation, and precise spatial positioning. Its core advantages are reflected in the following aspects:

[0066] The cut stress model is given by the formula: Express;

[0067] in, is the excavation stress, which represents the stress distribution at a horizontal distance x from the excavation surface at time t; is the excavation depth at time t;

[0068] is the weight of balancing soil layer information in the entire stress model; L is the soil layer action value;

[0069] To balance the weight of groundwater information in the entire stress model; W is the groundwater action value;

[0070] To balance the weight of plastic body stress in the entire stress model; is the plastic body stress, which represents the excavation depth at time t and the stress distribution function of the plastic body at the horizontal distance x;

[0071] Specifically,

[0072] ;in, is the coefficient of soil type of layer i; n is the number of soil layers; is the thickness of the i-th soil layer; is the soil density of the i-th layer; is the internal friction angle of the i-th layer of soil; is the soil cohesion of the i-th layer; the model automatically allocates attention according to the geological conditions, such as paying more attention to soil parameters in soft soil layers and paying more attention to groundwater impact in sand layers.

[0073] ;in, is the groundwater level influence coefficient; is the influence coefficient of groundwater flow direction, is the flow rate, is the flow angle; is the groundwater pressure influence coefficient, and the calculation formula is: , It is the weight of water.

[0074] ,in, is the stress response coefficient of the plastic body; is the excavation depth at time t and the stress distribution function at the horizontal distance x; is the influence function of the stress release zone, indicating whether the point at a horizontal distance x from the excavation surface is located in the stress release zone at time t;

[0075] Specifically, , where k1, k2 and k3 are adjustment coefficients, representing the effects of excavation depth, excavation speed and horizontal distance on stress distribution respectively; H is the total excavation depth; is the excavation speed; x s is the centerline position of the stress relief zone; q is the width of the stress relief zone; if , otherwise 0.

[0076] The following steps are used to obtain a stress change report for the stress relief zone during construction using the excavation stress model:

[0077] Step 21: Simulate different time points of the construction process in the excavation stress model to obtain the construction stress distribution information at different time points in the stress release zone. The collection frequency is related to the construction progress. For example, if the construction stress distribution information is collected every 6 hours, the profit data at several discrete time points can be obtained.

[0078] Step 22: Fit the construction stress distribution information at different time points to generate a fitted stress report for the stress release zone. Stress data at discrete time points is fitted into a continuous curve to generate an "excavation stress-time curve," which displays the stress trend over time. Key data is summarized, including the maximum stress value at each time point, its corresponding location, and the percentage deviation from the threshold. The stress change report includes a time-dependent excavation stress change graph (with time on the horizontal axis and stress value on the vertical axis, with the threshold line marked) and a table of key data (time, maximum stress, distance from the excavation face, and whether the threshold was exceeded).

[0079] Step 23: Determine whether any stress values ​​in the fitted stress report exceed the control threshold. If so, optimize the construction plan; otherwise, use the fitted stress report as a stress change report. For example, the control threshold for soft clay layers is 120 kPa, and for sand layers, 150 kPa. During rainy season, the control threshold should be reduced by 10% to provide a safety margin. If stress exceeds the limit in a particular area, immediately reduce the excavation speed to minimize transient disturbances. Increase support density (e.g., increase anchor bolt spacing from 20 m to 10 m) or upgrade the support type in stress-concentrated areas. Construction plan parameters include excavation depth, width, speed, and construction sequence.

[0080] The layout position of the plastic body is the area where the ground uplift in the stress release area is greater than the uplift threshold in the construction stress distribution information. , k is the elastic coefficient of the stress release zone (the stress release zone may be composed of soft soil layers, sand layers, etc., and its elastic coefficient is a composite value, the specific value is provided by the surveying and mapping party), is the stress difference between two construction times at a certain point. The uplift threshold refers to the maximum allowable uplift in the Technical Specifications for Urban Subway Construction, i.e. .

[0081] The size and distribution of the plastic body depend on the amount of ground uplift. Taking the selection of the bladder grouting device for the plastic body as an example, first outline the range where the ground uplift exceeds the threshold, and then evenly arrange the bladder grouting device and cover the ground uplift area. The layout depth should be no less than 1.5 times the expected excavation depth.

[0082] Fitting the construction stress distribution information at different time points to obtain a fitting stress report for the stress release area includes the following steps:

[0083] Step 221: Extract construction stress distribution data at multiple discrete time points during the construction process and verify its integrity. Extract stress data at multiple discrete time points and check data integrity, such as filling in missing values ​​and removing outliers.

[0084] Step 222: Based on the nonlinear characteristics of the time interval and stress distribution, a cubic spline interpolation method is selected, whose interpolation function satisfies the boundary condition of second-order continuous differentiability, to establish a time-stress distribution model. Based on the nonlinear characteristics of the data (such as sudden or gradual stress rise), a cubic spline interpolation method is selected and a piecewise polynomial function is constructed to ensure that the curve is smooth at the nodes.

[0085] Step 223: Based on the time-stress distribution model, interpolation is performed to generate a stress distribution curve of a continuous time series, and interpolation stress values ​​at each horizontal distance in the stress release area are extracted.

[0086] Step 224: Construct a dynamic stress cloud map of the stress release zone based on the interpolated stress values, and annotate the maximum stress value and its corresponding location and time node. Map the interpolated stress values ​​to a spatiotemporal distribution cloud map, use a color gradient to represent the stress magnitude, and annotate the maximum value and its spatiotemporal coordinates.

[0087] Step 225: Compare the dynamic stress cloud map with the simulated ground stress data of the excavation stress model to generate a fitting stress report including stress deviation analysis.

[0088] Step 226: If the deviation between the interpolated stress value and the simulated ground stress data exceeds a preset tolerance threshold (e.g., >5%), reselect the interpolation method or adjust the interpolation parameters and repeat steps 223 to 225 until the deviation meets the preset tolerance threshold.

[0089] Obtaining ground stress release information based on the stress change report and the characteristic data of the plastic body includes the following steps:

[0090] Step 31: Obtain the continuous stress distribution data of the stress release zone from the stress change report, and calculate the release strength of all plastic bodies at each time node;

[0091] Step 32: Determine whether the release strength of the plastic body obtained in step 31 will cause a bulge in the stress release area. If so, compensate for the release strength of the plastic body adjacent to the bulge and execute step 32 again. Otherwise, execute step 33.

[0092] Step 33: Fit the release strength of the same plastic body at all time points, and use the fitted release strength and the layout position of the plastic body as the ground stress release information.

[0093] Example 2, based on the in-situ stress control method for subway expansion deformation control provided in Example 1, provides a construction method for an in-situ stress control system. A bladder-type stress compensation and release device is deployed based on the selected plastic body placement location in the in-situ stress control system. Specifically, this involves drilling the bladder bag, lowering it, pre-reserving grouting, installing a drainage pipe, and grouting filling. After the compensation and release device is installed, stress release or compensation is performed based on the in-situ stress release information to adjust the deformation of structures such as subways. After completion, the bladder hole is solidified.

[0094] The above description is only a preferred specific implementation method of the present application and does not limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A method for controlling ground stress during subway expansion and construction, characterized in that: The following steps are involved: Step 1: Obtain geological data of the subway expansion site and use it to construct an excavation stress model; Step 2: Use the excavation stress model to obtain the stress change report of the stress release zone under the construction process; Step 3: Obtain ground stress release information based on the stress change report and the characteristic data of the plastic body; Step 4: Obtain the real-time in-situ stress data of the stress release zone during the construction process and the simulated in-situ stress data corresponding to the excavation stress model, and compare the real-time in-situ stress data with the simulated in-situ stress data to obtain in-situ stress release correction information; The acquisition of geological data at the subway construction site and the construction of an excavation stress model using the geological data include the following steps: Step 11: Use the soil layer information and groundwater information obtained from the subway construction site survey as geological data; Step 12: Construct an initial stress model using geological data based on finite element analysis; Step 13: Set the stress release area in the initial stress model to obtain the excavation stress model; in, The soil layer information includes soil layer type, soil layer thickness, soil layer distribution and mechanical parameters; The mechanical parameters include soil density, soil internal friction angle, and soil cohesion; The groundwater information includes groundwater level, groundwater flow data and groundwater pressure; The stress relief zone is a width band 5-10m away from the subway; The excavation stress model is expressed as follows: S(x,D t )=α×L+β×W+γ×S p (x,D t )Express; Among them, S(x, D t ) is the excavation stress, which represents the stress distribution at a horizontal distance x from the excavation surface at time t; D t is the excavation depth at time t; α is the weight of the equilibrium soil layer information in the entire stress model; L is the soil layer action value; β is the weight of the balanced groundwater information in the entire stress model; W is the groundwater action value; γ is the weight of the balanced plastic body stress in the entire stress model; S p (x,D t ) is the plastic body stress, indicating the excavation depth D at time t t and the stress distribution function of the plastic body at the horizontal distance x; Among them, T i is the coefficient of the soil type of the i-th layer; n is the number of soil layers; H i is the thickness of the i-th soil layer; ρ i is the soil density of the i-th layer; φ i is the internal friction angle of the i-th layer of soil; c i is the soil cohesion of the i-th layer; W=G w ×Vcosθ+F g Among them, G w is the influence coefficient of groundwater level; Vcosθ is the influence coefficient of groundwater flow direction, V is the flow velocity, θ is the flow angle; F g is the groundwater pressure influence coefficient, and the calculation formula is: F g =γ w ×|G w ∣, γ w It is the weight of water; S p (x,D t )=η×σ(D t , x)×I(x, D t ); where η is the stress response coefficient of the plastic body; σ(D t , x) is the excavation depth D at time t t and the stress distribution function at the horizontal distance x; I(x, D t ) is the influence function of the stress release zone, indicating whether the point at a horizontal distance x from the excavation surface is located in the stress release zone at time t; σ(D t , x)=k1×(D t / H)+k2×(dD t / dt)+k3×(xx s ) / q, where k1, k2 and k3 is the adjustment coefficient, which represents the influence of excavation depth, excavation speed and horizontal distance on stress distribution; H is the total excavation depth; dD t / dt is the excavation speed; x s is the centerline position of the stress relief zone; q is the width of the stress relief zone; If ∣xx s ∣≤q / 2, then I(x, D t )=1, otherwise it is 0.

2. A method for controlling ground stress during subway expansion and construction deformation according to claim 1, characterized in that: The method of obtaining a stress change report of a stress release zone during a construction process by using an excavation stress model comprises the following steps: Step 21: Simulate different time points of the construction process in the excavation stress model to obtain construction stress distribution information at different time points in the stress release zone; Step 22: Fitting the construction stress distribution information at different time points to obtain a fitting stress report of the stress release area; Step 23: Determine whether there is a stress value exceeding the control threshold in the fitting stress report. If so, optimize the construction plan; otherwise, use the fitting stress report as a stress change report.

3. A method for controlling ground stress during subway expansion and construction deformation according to claim 2, characterized in that: The layout position of the plastic body is the area in the construction stress distribution information where the ground uplift in the stress release area is greater than the uplift threshold, and the ground uplift U=k×ΔS, k is the elastic coefficient of the stress release area, and ΔS is the stress value difference between two construction times at a certain point.

4. A method for controlling ground stress during subway expansion and construction deformation according to claim 3, characterized in that: The fitting stress report of the stress release zone obtained by fitting the construction stress distribution information at different time points includes the following steps: Step 221: extracting construction stress distribution data at multiple discrete time points in the construction process and verifying its integrity; Step 222: Based on the nonlinear characteristics of the time interval and stress distribution, a cubic spline interpolation method is selected, whose interpolation function satisfies the second-order continuous and differentiable boundary conditions, to establish a time-stress distribution model; Step 223: interpolating and generating a stress distribution curve of a continuous time series according to the time-stress distribution model, and extracting the interpolated stress value at each horizontal distance in the stress release area; Step 224: constructing a dynamic stress cloud map of the stress release area based on the interpolated stress value, and marking the maximum stress value and its corresponding position and time node; Step 225: Compare the dynamic stress cloud map with the simulated ground stress data of the excavation stress model to generate a fitting stress report including a stress deviation analysis; Step 226: If the deviation between the interpolated stress value and the simulated in-situ stress data exceeds a preset tolerance threshold, reselect the interpolation method or adjust the interpolation parameters and repeat steps 223 to 225 until the deviation meets the preset tolerance threshold.

5. The method for controlling ground stress during subway expansion and construction deformation according to claim 4 is characterized in that: The method of obtaining ground stress release information based on the stress change report and the characteristic data of the plastic body comprises the following steps: Step 31: Obtain the continuous stress distribution data of the stress release zone from the stress change report, and calculate the release strength of all plastic bodies at each time node; Step 32: Determine whether the release strength of the plastic body obtained in step 31 will cause a bulge in the stress release area. If so, compensate for the release strength of the plastic body adjacent to the bulge and execute step 32 again. Otherwise, execute step 33. Step 33: Fit the release strength of the same plastic body at all time points, and use the fitted release strength and the layout position of the plastic body as the ground stress release information.

Images