A shield tunnel ground surface settlement deformation prediction method and system

Abstract

The application provides a shield tunnel ground surface settlement deformation prediction method and system, relates to the tunnel construction technical field, and includes the following steps: determining the relaxation effect zone range caused by the shield tail gap based on the shield tail gap geometric parameters; constructing the shield tail gap geometric distribution function, the stress release function and the time effect function based on the construction data, and constructing the relaxation effect zone shrinkage function; calculating the foundation ground surface settlement by using the integral method according to the relaxation effect zone range, the relaxation effect zone shrinkage function and the burial depth influence parameters; calculating the nonlinear correction coefficient, the burial depth influence coefficient and the grouting effect coefficient respectively according to the soil modulus parameters, the burial depth parameters and the grouting parameters; and correcting the foundation ground surface settlement based on the nonlinear correction coefficient, the burial depth influence coefficient and the grouting effect coefficient to obtain the corrected ground surface settlement. The application establishes a ground surface settlement model considering the soil nonlinear characteristics, the stress path effect and the space-time evolution characteristics, and provides a scientific basis for the stratum deformation control of shield construction.

Description

Technical Field

[0001] This invention belongs to the field of tunnel construction technology, specifically relating to a method and system for predicting surface settlement and deformation in shield tunnels. Background Technology

[0002] With the rapid development of urban rail transit construction, shield tunneling has become one of the main construction methods for underground space development. During shield tunneling, after the segments are assembled, the tunnel boring machine continues to advance, creating a certain length of tail gap between the cutterhead and the assembled segments. The existence of this gap causes the surrounding soil to move into the gap, resulting in stress release and relaxation effects, which in turn leads to ground loss and surface settlement deformation. If the settlement deformation exceeds the control standards, it will seriously threaten the safety of surface buildings and underground pipelines.

[0003] Currently, scholars both domestically and internationally have conducted some research on predicting ground settlement caused by tunnel boring machine (TBM) construction. Existing technologies are mainly based on empirical formulas, stochastic medium theory, or numerical simulation methods, considering the influence of factors such as ground loss rate on surface settlement. However, existing technologies have not systematically revealed the mechanical mechanism and deformation law of soil relaxation effect caused by the tail gap between the cutterhead and the tunnel segments during TBM tunneling. There is a lack of analytical methods to quantitatively predict surface settlement deformation caused by the relaxation effect, making it difficult to provide a theoretical basis for the optimization and control of TBM construction parameters and the prediction of surface settlement. Summary of the Invention

[0004] The purpose of this invention is to provide a method and system for predicting surface settlement and deformation in shield tunnels, thereby improving the aforementioned problems. To achieve this objective, the technical solution adopted by this invention is as follows:

[0005] In a first aspect, this application provides a method for predicting surface settlement and deformation in shield tunnels, including:

[0006] Obtain the geometric parameters of the shield tail gap;

[0007] The extent of the relaxation effect zone caused by the shield tail gap is determined based on the geometric parameters of the shield tail gap.

[0008] Based on construction data, construct the shield tail void geometric distribution function, stress release function, and time effect function;

[0009] A contraction function for the relaxation effect zone is constructed based on the geometric distribution function, stress release function, and time effect function.

[0010] Based on the extent of the relaxation effect zone, the contraction function of the relaxation effect zone, and the burial depth influence parameters, the integral method is used to calculate the foundation surface settlement.

[0011] Calculate the nonlinear correction coefficient, burial depth influence coefficient, and grouting effect coefficient based on the soil modulus parameters, burial depth parameters, and grouting parameters, respectively.

[0012] The ground settlement of the foundation is corrected based on the nonlinear correction coefficient, the burial depth influence coefficient, and the grouting effect coefficient, and the corrected ground settlement is obtained.

[0013] Secondly, a surface settlement and deformation prediction system for shield tunnels includes:

[0014] The first module is used to obtain the geometric parameters of the shield tail gap;

[0015] The second module is used to determine the range of the relaxation effect zone caused by the shield tail gap based on the shield tail gap geometry parameters;

[0016] The third module is used to construct the shield tail void geometric distribution function, stress release function, and time effect function based on construction data;

[0017] The fourth module is used to construct the relaxation effect zone contraction function based on the geometric distribution function, stress release function, and time effect function;

[0018] The fifth module is used to calculate the foundation surface settlement using the integral method based on the range of the relaxation effect zone, the contraction function of the relaxation effect zone, and the burial depth influence parameters.

[0019] The sixth module is used to calculate the nonlinear correction coefficient, burial depth influence coefficient, and grouting effect coefficient based on the soil modulus parameter, burial depth parameter, and grouting parameter, respectively.

[0020] The seventh module is used to correct the foundation surface settlement based on the nonlinear correction coefficient, the burial depth influence coefficient, and the grouting effect coefficient, so as to obtain the corrected surface settlement.

[0021] The beneficial effects of this invention are as follows:

[0022] Based on the theory of random media and the concept of relaxation effect zone, this invention establishes a surface settlement prediction model for the relaxation effect of shield tail voids, which takes into account the influence of multiple factors. This realizes the leap from qualitative analysis to quantitative prediction. It introduces correction coefficients for soil nonlinearity, burial depth, grouting effect, and time effect, so that the prediction model can adapt to different geological conditions and construction conditions. It has a wide range of applications and strong practicality.

[0023] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing embodiments of the invention. Attached Figure Description

[0024] 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 on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a flowchart illustrating the method for predicting surface settlement and deformation of shield tunnels according to an embodiment of this application.

[0026] Figure 2 This is a structural diagram of the shield tunnel surface settlement and deformation prediction device according to an embodiment of this application.

[0027] Symbol explanation: 800 - Shield tunnel surface settlement and deformation prediction equipment; 801 - Processor; 802 - Memory; 803 - Multimedia component; 804 - I / O interface; 805 - Communication component. Detailed Implementation

[0028] 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, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0029] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0030] Through a combination of theoretical analysis and indoor model tests, it was found that the tail gap between the cutterhead and the tunnel segments during shield tunneling will cause stress release and relaxation effects in the surrounding soil. The mechanical mechanism is as follows: when the tunnel segments detach from the tail, the support of the shield shell on the soil disappears, and the surrounding soil moves into the tail gap under the action of self-weight stress and tectonic stress, resulting in stress release and strain softening, forming a "relaxation effect zone". The relaxation effect has the following characteristics: (1) Along the longitudinal direction of the tunnel, the relaxation effect gradually increases with the distance from the tail, reaches a peak within a certain range behind the tail, and then tends to stabilize; (2) Along the transverse direction of the tunnel, the relaxation effect is most significant above the tunnel arch and gradually weakens to both sides; (3) The relaxation effect has obvious time correlation, and the soil deformation continues to develop with the extension of the exposure time of the tail gap, showing creep characteristics; (4) The intensity of the relaxation effect is closely related to the size of the tail gap, the mechanical properties of the soil, the tunnel burial depth, and other factors. Based on the above deformation characteristics, and taking into account the influence of multiple factors such as shield tail void, soil mechanical properties, tunnel depth, grouting effect, and time effect, this application establishes a prediction model for surface settlement deformation caused by shield tail void relaxation effect.

[0031] Example 1:

[0032] See Figure 1 This application provides a method for predicting surface settlement and deformation of shield tunnels, including steps S100, S200, S300, S400, S500, S600, and S700.

[0033] S100, Obtain the geometric parameters of the shield tail gap;

[0034] The tail clearance consists of three parts: the over-excavation clearance of the tunnel boring machine cutterhead, the tail shell thickness clearance, and the grouting shrinkage clearance behind the wall; therefore, this step includes:

[0035] The cutterhead over-digging clearance is calculated based on the cutterhead diameter and the shield outer diameter.

[0036] g1 = (D c -D b ) / 2;

[0037] Where g1 is the cutterhead over-digging clearance, D c D is the diameter of the cutter head. b The outer diameter of the shield;

[0038] Obtain the shield thickness gap g2; the shield thickness gap is the shield thickness.

[0039] The grout shrinkage gap is calculated based on the grout volume shrinkage rate and the initial grout filling thickness.

[0040] g3 = η × g4;

[0041] Where g3 is the grouting shrinkage gap, η is the grout volume shrinkage rate, and g4 is the initial grouting filling thickness;

[0042] The total tail clearance is calculated based on the cutterhead over-digging clearance, shield shell thickness clearance, and grouting shrinkage clearance.

[0043] g=g 1+ g 2+ g3;

[0044] Where g is the total shield tail clearance, g1 is the cutterhead over-excavation clearance, g2 is the shield shell thickness clearance, and g3 is the grouting shrinkage clearance.

[0045] S200. Determine the range of the relaxation effect zone caused by the shield tail gap based on the geometric parameters of the shield tail gap.

[0046] This step, based on the limit equilibrium theory and the principle of soil arching, determines the extent of the relaxation effect zone caused by the shield tail void:

[0047] S210. Calculate the longitudinal relaxation length based on the tunnel diameter, tunnel depth, and shield tail gap.

[0048] ;

[0049] in, The longitudinal relaxation length, D The diameter of the tunnel. H For tunnel burial depth, For the total shield tail gap, For reference gap, , These are empirical coefficients, with values ​​ranging from 2.5 to 3.5 and from 0.2 to 0.4, respectively.

[0050] S220. Calculate the transverse relaxation width based on the tunnel diameter, tunnel depth, and soil internal friction angle.

[0051] ;

[0052] in, The horizontal relaxation width, The internal friction angle of the soil. D The diameter of the tunnel. H For tunnel burial depth, The porosity influence coefficient is... , The value ranges from 0.5 to 1.0;

[0053] S230. Calculate the vertical relaxation height based on the tunnel diameter, tunnel depth, and soil type.

[0054] ;

[0055] in, The vertical relaxation height, D The diameter of the tunnel. H For tunnel burial depth, The attenuation coefficient; This is a soil type correction factor, with 0.8 to 1.0 for sandy soil and 0.6 to 0.8 for clay.

[0056] S300, construct the shield tail void geometric distribution function, stress release function and time effect function based on construction data;

[0057] S310. Construct the shield tail gap geometric distribution function based on the shield tail gap geometric parameters;

[0058] ;

[0059] in, The shield tail void geometric distribution function, For the total shield tail gap, Over-excavation volume (depending on the geological conditions and the type of tunnel boring machine); The coefficient is non-uniform (0~0.3, depending on the shield attitude). The circumferential angle (0° is the arch). The maximum gap direction angle;

[0060] S320. Based on the shield tail position, construct a piecewise linear spatial distribution function; based on the shield tail exit time, construct a time evolution function.

[0061]

[0062] in, is the spatial distribution function, where s is the longitudinal coordinate (the shield tail position is the origin, and negative values ​​represent the area that has been removed). The initial release potential before the shield tail detaches (0.2~0.4). To ultimately unleash its potential (0.9~1.0); The length of the shield tail influence zone (0.5D~2D); Transition zone length (2D~5D);

[0063] The time evolution function reflects the settlement development over time and can be represented by a hyperbolic model:

[0064] ;

[0065] in, For time evolution function, t For time, a and b are empirical parameters reflecting the settlement rate, which can be determined by fitting indoor test or field monitoring data.

[0066] S330. Multiply the spatial distribution function and the time evolution function to obtain the stress release function;

[0067] ;

[0068] in, For stress relief function, For time evolution function, It is a spatial distribution function;

[0069] S340. Construct a time-effect function reflecting the change of settlement over time using experimental data or field monitoring data;

[0070] The time-effect function constructed in this embodiment is as follows:

[0071]

[0072] in, For time effect function, This is the time of settlement initiation; For the time it takes for the shield tail to pass through the monitoring section; It is a time constant, reflecting the rate of settlement development; The initial settlement coefficient is taken as 0.1-0.3;

[0073] S400, a relaxation effect zone contraction function is constructed based on the geometric distribution function, stress release function, and time effect function:

[0074] ;

[0075] in, The contraction function of the relaxation effect region. For time effect function, For stress relief function, The shield tail void geometry distribution function;

[0076] S500. Based on the range of the relaxation effect zone, the contraction function of the relaxation effect zone, and the burial depth influence parameters, the surface settlement of the foundation is calculated using the integral method.

[0077] ;

[0078] in, Based on surface subsidence; This is the integration region of the relaxation effect. The tangent of the formation fracture angle. Parameters affecting burial depth; The contraction function of the relaxation effect zone; The vertical coordinates of the Earth's surface The horizontal coordinates of the Earth's surface; The tunnel is transverse. For the vertical direction of the tunnel;

[0079] S600. Based on the soil modulus parameters, burial depth parameters, and grouting parameters, calculate the nonlinear correction coefficient, burial depth influence coefficient, and grouting effect coefficient, as detailed below:

[0080] S610. Calculate the nonlinearity correction coefficient of the soil based on the secant modulus and loading / unloading modulus of the soil.

[0081] ;

[0082] in, This is the soil nonlinearity correction factor. Secant modulus of soil; For loading and unloading modulus of soil; It is a non-linear exponent, with a value range of 0.2-0.4.

[0083] S620. Calculate the burial depth influence coefficient based on the tunnel diameter and tunnel burial depth;

[0084] ;

[0085] in, The burial depth influence coefficient is... D The diameter of the tunnel. H For tunnel burial depth, This is an empirical coefficient, with a value range of 0.3-0.5.

[0086] S630. Creep tests were conducted on soil samples to determine the time required to achieve 90% final settlement. ;

[0087] S640. Calculate the time effect coefficient based on the time it takes to reach 90% of the final settlement.

[0088] ;

[0089] in, This is the time effect coefficient. The creep index is... To achieve 90% final settlement time; This refers to the time after grouting;

[0090] S650. Calculate the grouting effect coefficient based on grouting pressure, vertical self-weight stress, and initial setting time of the grout.

[0091] ;

[0092] in, This is the grouting effect coefficient; This refers to the grouting pressure; The stress is the vertical self-weight stress; This refers to the time after grouting; This refers to the initial setting time of the grout. This is the grouting efficiency coefficient;

[0093] S700, based on the nonlinear correction coefficient, burial depth influence coefficient, and grouting effect coefficient, corrects the foundation surface settlement to obtain the corrected surface settlement.

[0094] ;

[0095] in, Corrected surface subsidence This is the soil nonlinearity correction factor. The burial depth influence coefficient is... This is the time effect coefficient. This is the grouting effect coefficient; Based on surface subsidence; For the total shield tail gap; D The diameter of the tunnel; This refers to the time after grouting; , To comprehensively correct the parameters, they can be determined through inversion using on-site monitoring data.

[0096] Example 2:

[0097] A surface settlement and deformation prediction system for shield tunnels includes:

[0098] The first module is used to obtain the geometric parameters of the shield tail gap;

[0099] The second module is used to determine the range of the relaxation effect zone caused by the shield tail gap based on the shield tail gap geometry parameters;

[0100] The third module is used to construct the shield tail void geometric distribution function, stress release function, and time effect function based on construction data;

[0101] The fourth module is used to construct the relaxation effect zone contraction function based on the geometric distribution function, stress release function, and time effect function;

[0102] The fifth module is used to calculate the foundation surface settlement using the integral method based on the range of the relaxation effect zone, the contraction function of the relaxation effect zone, and the burial depth influence parameters.

[0103] The sixth module is used to calculate the nonlinear correction coefficient, burial depth influence coefficient, and grouting effect coefficient based on the soil modulus parameter, burial depth parameter, and grouting parameter, respectively.

[0104] The seventh module is used to correct the foundation surface settlement based on the nonlinear correction coefficient, the burial depth influence coefficient, and the grouting effect coefficient, so as to obtain the corrected surface settlement.

[0105] As an optional implementation, the second module includes:

[0106] The first unit is used to calculate the longitudinal relaxation length based on the tunnel diameter, tunnel depth and shield tail gap;

[0107] The second unit is used to calculate the lateral relaxation width based on the tunnel diameter, tunnel depth and soil internal friction angle.

[0108] The third unit is used to calculate the vertical relaxation height based on the tunnel diameter, tunnel depth, and soil type.

[0109] As an optional implementation, the third module includes:

[0110] The fourth unit is used to construct the shield tail gap geometric distribution function based on the shield tail gap geometric parameters;

[0111] The fifth unit is used to construct a piecewise linear spatial distribution function based on the shield tail position and a time evolution function based on the shield tail exit time.

[0112] The sixth unit is used to multiply the spatial distribution function and the time evolution function to obtain the stress release function;

[0113] Unit 7 is used to construct a time-effect function that reflects the change of settlement over time using experimental data or field monitoring data.

[0114] As an optional implementation, the sixth module includes:

[0115] The eighth unit is used to calculate the nonlinearity correction coefficient of the soil based on the secant modulus and loading / unloading modulus of the soil.

[0116] Unit 9 is used to calculate the burial depth influence coefficient based on the tunnel diameter and tunnel burial depth;

[0117] Unit 10 is used to conduct creep tests on soil samples to determine the time required to reach 90% final settlement.

[0118] Unit 11 is used to calculate the time effect coefficient based on the time to reach 90% final settlement;

[0119] Unit 12 is used to calculate the grouting effect coefficient based on grouting pressure, vertical self-weight stress, and initial setting time of the grout.

[0120] Example 3:

[0121] Corresponding to the above method embodiments, this embodiment also provides a shield tunnel surface settlement deformation prediction device. The shield tunnel surface settlement deformation prediction device described below can be referred to in correspondence with the shield tunnel surface settlement deformation prediction method described above.

[0122] Figure 2 This is a block diagram illustrating a shield tunnel surface settlement and deformation prediction device 800 according to an exemplary embodiment. Figure 2 As shown, the shield tunnel surface settlement deformation prediction device 800 includes a processor 801 and a memory 802. The shield tunnel surface settlement deformation prediction device 800 may also include one or more of the following: a multimedia component 803, an input / output (I / O) interface 804, and a communication component 805. The processor 801 controls the overall operation of the shield tunnel surface settlement deformation prediction device 800 to complete all or part of the steps in the aforementioned shield tunnel surface settlement deformation prediction method. The memory 802 stores various types of data to support the operation of the shield tunnel surface settlement deformation prediction device 800. This data may include, for example, commands for any application or method operating on the shield tunnel surface settlement deformation prediction device 800, and application-related data such as contact data, sent and received messages, images, audio, video, etc. The memory 802 can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, magnetic disk or optical disk.

[0123] Multimedia component 803 may include a screen and an audio component. The screen may be, for example, a touchscreen, and the audio component is used to output and / or input audio signals. For example, the audio component may include a microphone for receiving external audio signals.

[0124] The received audio signals can be further stored in memory 802 or transmitted via communication component 805. The audio component also includes at least one speaker for outputting audio signals. I / O interface 804 provides an interface between processor 801 and other interface modules, such as a keyboard, mouse, buttons, etc. These buttons can be virtual or physical. Communication component 805 is used for wired or wireless communication between the shield tunnel surface settlement deformation prediction device 800 and other devices. Wireless communication, such as Wi-Fi, Bluetooth, Near Field Communication (NFC), 2G, 3G, or 4G, or a combination thereof, is used. Therefore, the corresponding communication component 805 may include a Wi-Fi module, a Bluetooth module, or an NFC module.

[0125] Example 4:

[0126] Corresponding to the above embodiment of the method for predicting surface settlement and deformation of shield tunnels, this embodiment also provides a readable storage medium. The readable storage medium described below can be referred to in correspondence with the above-described method for predicting surface settlement and deformation of shield tunnels.

[0127] A readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the above-described method for predicting surface settlement and deformation in shield tunnels.

[0128] Specifically, the readable storage medium can be a USB flash drive, external hard drive, read-only memory (ROM), random access memory (RAM), magnetic disk, or optical disk, or any other readable storage medium capable of storing program code.

[0129] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0130] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for predicting surface settlement and deformation in shield tunnels, characterized in that, include: Obtain the geometric parameters of the shield tail gap; The extent of the relaxation effect zone caused by the shield tail gap is determined based on the geometric parameters of the shield tail gap. Based on construction data, construct the shield tail void geometric distribution function, stress release function, and time effect function; A contraction function for the relaxation effect zone is constructed based on the geometric distribution function, stress release function, and time effect function. Based on the extent of the relaxation effect zone, the contraction function of the relaxation effect zone, and the burial depth influence parameters, the integral method is used to calculate the foundation surface settlement. Calculate the nonlinear correction coefficient, burial depth influence coefficient, and grouting effect coefficient based on the soil modulus parameters, burial depth parameters, and grouting parameters, respectively. The ground settlement of the foundation is corrected based on the nonlinear correction coefficient, the burial depth influence coefficient, and the grouting effect coefficient, and the corrected ground settlement is obtained.

2. The method for predicting surface settlement and deformation of a shield tunnel according to claim 1, characterized in that, The extent of the relaxation effect zone caused by the shield tail gap is determined based on the shield tail gap geometry parameters, including: The longitudinal relaxation length is calculated based on the tunnel diameter, tunnel depth, and shield tail gap. The transverse relaxation width is calculated based on the tunnel diameter, tunnel depth, and soil internal friction angle. The vertical relaxation height is calculated based on the tunnel diameter, tunnel depth, and soil type.

3. The method for predicting surface settlement and deformation of a shield tunnel according to claim 1, characterized in that, The construction of the shield tail void geometric distribution function, stress release function, and time effect function based on construction data includes: Construct the shield tail gap geometric distribution function based on the shield tail gap geometric parameters; Based on the shield tail position, a piecewise linear spatial distribution function is constructed; based on the shield tail exit time, a time evolution function is constructed. Multiplying the spatial distribution function and the time evolution function yields the stress release function; A time-effect function reflecting the change of settlement over time is constructed using experimental data or field monitoring data.

4. The method for predicting surface settlement and deformation of a shield tunnel according to claim 1, characterized in that, The calculation of nonlinear correction coefficients, burial depth influence coefficients, and grouting effect coefficients based on soil modulus parameters, burial depth parameters, and grouting parameters includes: Calculate the nonlinearity correction coefficient of the soil based on the secant modulus and loading / unloading modulus of the soil. Calculate the burial depth influence coefficient based on the tunnel diameter and tunnel burial depth; Creep tests were conducted on soil samples to determine the time required for 90% final settlement. The time effect coefficient is calculated based on the time it takes to reach 90% of the final settlement. The grouting effect coefficient is calculated based on the grouting pressure, vertical self-weight stress, and initial setting time of the grout.

5. The method for predicting surface settlement and deformation of a shield tunnel according to claim 1, characterized in that, Obtain the geometric parameters of the shield tail gap, including: The cutterhead over-digging clearance is calculated based on the cutterhead diameter and the shield outer diameter. Obtain the shield thickness gap; The grout shrinkage gap is calculated based on the grout volume shrinkage rate and the initial grout filling thickness. The total shield thickness was calculated based on the cutterhead over-digging clearance, shield shell thickness clearance, and grouting shrinkage clearance. Tail gap.

6. The method for predicting surface settlement and deformation of a shield tunnel according to claim 1, characterized in that, The method includes: Tunnels can be classified into deep-buried tunnels and shallow-buried tunnels based on their burial depth. Find the initial burial depth influence parameters corresponding to deep-buried tunnels and shallow-buried tunnels; The initial burial depth influence parameters are corrected based on the soil and rock type and tunnel size to obtain the tunnel burial depth influence parameters.

7. A surface settlement and deformation prediction system for shield tunnels, characterized in that, include: The first module is used to obtain the geometric parameters of the shield tail gap; The second module is used to determine the range of the relaxation effect zone caused by the shield tail gap based on the shield tail gap geometry parameters; The third module is used to construct the shield tail void geometric distribution function, stress release function, and time effect function based on construction data; The fourth module is used to construct the relaxation effect zone contraction function based on the geometric distribution function, stress release function, and time effect function; The fifth module is used to calculate the foundation surface settlement using the integral method based on the range of the relaxation effect zone, the contraction function of the relaxation effect zone, and the burial depth influence parameters. The sixth module is used to calculate the nonlinear correction coefficient, burial depth influence coefficient, and grouting effect coefficient based on the soil modulus parameter, burial depth parameter, and grouting parameter, respectively. The seventh module is used to correct the foundation surface settlement based on the nonlinear correction coefficient, the burial depth influence coefficient, and the grouting effect coefficient, so as to obtain the corrected surface settlement.

8. The surface settlement and deformation prediction system for shield tunnels according to claim 7, characterized in that, The second module includes: The first unit is used to calculate the longitudinal relaxation length based on the tunnel diameter, tunnel depth and shield tail gap; The second unit is used to calculate the lateral relaxation width based on the tunnel diameter, tunnel depth and soil internal friction angle. The third unit is used to calculate the vertical relaxation height based on the tunnel diameter, tunnel depth, and soil type.

9. A surface settlement and deformation prediction system for shield tunnels according to claim 7, characterized in that, The third module includes: The fourth unit is used to construct the shield tail gap geometric distribution function based on the shield tail gap geometric parameters; The fifth unit is used to construct a piecewise linear spatial distribution function based on the shield tail position and a time evolution function based on the shield tail exit time. The sixth unit is used to multiply the spatial distribution function and the time evolution function to obtain the stress release function; Unit 7 is used to construct a time-effect function that reflects the change of settlement over time using experimental data or field monitoring data.

10. A surface settlement and deformation prediction system for shield tunnels according to claim 7, characterized in that, The sixth module includes: The eighth unit is used to calculate the nonlinearity correction coefficient of the soil based on the secant modulus and loading / unloading modulus of the soil. Unit 9 is used to calculate the burial depth influence coefficient based on the tunnel diameter and tunnel burial depth; Unit 10 is used to conduct creep tests on soil samples to determine the time required to reach 90% final settlement. Unit 11 is used to calculate the time effect coefficient based on the time to reach 90% final settlement; Unit 12 is used to calculate the grouting effect coefficient based on grouting pressure, vertical self-weight stress, and initial setting time of the grout.

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