A method for predicting deformation of submarine tunnels under earthquake action

Abstract

The present invention provides a method for predicting deformation of an undersea tunnel under earthquake action, which relates to the technical field of tunnel deformation prediction, and specifically comprises: constructing a fluid-structure-soil coupling model based on a finite element simulation method, simulating the influence of earthquakes on soil and tunnels by applying seismic waves, and recording dynamic parameters of the model; collecting environmental and material parameters of an actual tunnel, and then performing dimensionless processing on the parameters to calculate a first influence index and a second influence index; comprehensively analyzing the above indexes, calculating a comprehensive deformation index, and monitoring the ambient temperature in real time, incorporating a temperature compensation term, and obtaining a corrected tunnel deformation; the present invention can effectively solve the shortcomings of traditional prediction methods in complex earthquake environments by constructing a fluid-structure-soil coupling model, and provide a more accurate deformation prediction; comprehensively analyzing the first influence index and the second influence index can comprehensively reflect the actual deformation of the tunnel under the action of an earthquake.

Description

Technical Field

[0001] The invention relates to the technical field of tunnel deformation prediction, and in particular to a method for predicting deformation of a submarine tunnel under earthquake action. Background Art

[0002] With the acceleration of urbanization, undersea tunnels, as an important part of the transportation network, have gradually become an important channel connecting the two sides of the sea. However, the safety and stability of undersea tunnels are threatened by a variety of natural factors, especially earthquakes. Traditional deformation prediction technologies mainly rely on simplified theoretical models or empirical formulas, which cannot fully consider the complex behavior of undersea tunnels under complex geological conditions and dynamic loading. These methods often ignore the interaction between fluids, soil and tunnel structures, resulting in a significant reduction in the accuracy and reliability of the prediction results. In addition, the existing technology lacks effective comprehensive considerations when dealing with environmental factors such as soil pressure and seawater pressure, and cannot dynamically adapt to changes in actual conditions, which ultimately makes the assessment of tunnel safety present a greater risk.

[0003] Furthermore, in the dynamic analysis process, the existing technology can only perform static evaluation of a specific parameter, but cannot perform a comprehensive dynamic response analysis. This one-sided analysis method not only limits the in-depth understanding of the propagation characteristics of seismic waves and their impact on tunnel structures, but also fails to effectively capture the transient response behavior of tunnels under earthquakes. The lack of in-depth research on the complex coupling relationship between soil and tunnel structure means that traditional prediction methods are often unable to provide accurate deformation predictions when facing actual earthquake events, resulting in the inability to take effective defense measures in a timely manner. In addition, the impact of environmental changes such as temperature and humidity on tunnel structures has been ignored, further reducing the prediction accuracy. Therefore, there is an urgent need for a new and efficient method for predicting deformation of submarine tunnels to improve the accurate prediction of tunnel deformation under earthquakes and ensure its safety and stability.

[0004] The above information disclosed in this Background section is only for enhancement of understanding of the background of the present disclosure and therefore it may contain information that does not constitute the prior art that is already known to one of ordinary skill in the art. Summary of the invention

[0005] The purpose of the present invention is to provide a method for predicting deformation of a submarine tunnel under earthquake action, so as to solve the problems raised in the above-mentioned background technology.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A method for predicting deformation of a submarine tunnel under earthquake action, comprising the following specific steps:

[0008] Step 1: construct a fluid-structure-soil coupling model based on the finite element simulation method to simulate the complex environment under the action of an earthquake; apply seismic waves to the constructed fluid-structure-soil coupling model to simulate the impact of earthquake propagation on the soil and the tunnel, set dynamic analysis parameters in the finite element software, start dynamic analysis, and record the dynamic parameters of the model, which are displacement, strain and acceleration data of the model;

[0009] Step 2: Collecting environmental parameters and material parameters of the actual tunnel, wherein the environmental parameters are soil pressure data and seawater pressure data borne by the tunnel, and the material parameters are strength data and stiffness data of the tunnel; and generating a first impact index based on the dimensionless processed environmental parameters and material parameters, and generating a second impact index based on the dimensionless processed dynamic parameters;

[0010] Step 3: Combine the first influence index and the second influence index, perform correlation analysis, and calculate the comprehensive deformation index; monitor the tunnel ambient temperature in real time, incorporate the temperature compensation item into the comprehensive deformation index, and calculate the corrected deformation of the submarine tunnel;

[0011] Step 4: Regularly compare the model results with the actual monitoring data, perform model calibration, and verify the accuracy of the model.

[0012] Furthermore, the specific logic of constructing the fluid-structure-soil coupling model based on the finite element simulation method is as follows:

[0013] An initial finite element model is established using ABAQUS software through component and assembly modules, and the physical and mechanical properties of the soil and tunnel structure are defined, which are elastic modulus, Poisson's ratio, density and shear strength. The flow characteristics of seawater are defined, which are the viscosity and density of seawater. The geometric model is divided into several small units to form a grid, and three-dimensional hexahedral units are selected to improve the calculation accuracy. The grid is refined around the tunnel to improve the accuracy of the calculation. The boundary conditions between the tunnel and the seawater are set at both ends of the tunnel. By applying seismic waves as dynamic loads, the environmental changes under the action of earthquakes are simulated. The simulation program is run to perform dynamic analysis of the model and obtain the dynamic parameters of the model, which are displacement, stress, strain and acceleration.

[0014] Furthermore, the specific logic of the process of obtaining the model dynamic parameters is as follows:

[0015] During dynamic analysis, the equations of motion are solved by the finite element method:

[0016]

[0017] Among them, N is the mass matrix, describing the mass distribution of the system, u is the displacement vector, representing the displacement of each node in the system, C is the damping matrix, describing the damping characteristics of the system, K is the stiffness matrix, describing the stiffness distribution of the system, and F(t) is the force caused by the seismic wave, expressed as a time-dependent function;

[0018] By solving the above equation, we can obtain the node displacement u(t) at each time step, and by performing time differentiation on the displacement, we can obtain the velocity By differentiating the velocity with respect to time, we can obtain the acceleration ü(t):

[0019]

[0020] Calculate strain data using the stress-strain relationship:

[0021]

[0022] Among them, ∈ is the strain, L represents the original length of the structure, and Δu is the displacement change.

[0023] Furthermore, the process of collecting the environmental parameters and material parameters of the actual tunnel is specifically as follows:

[0024] The strength data is the ratio of the mass of steel bars and the mass of concrete used in the tunnel structure, and the stiffness data includes the average elastic modulus and average Poisson's ratio of the steel and concrete used in the tunnel structure;

[0025] The specific logic for collecting intensity data is:

[0026] The total concrete mass and total steel mass used to construct the tunnel structure are obtained, and the ratio of the steel mass to the concrete mass used in the tunnel structure is generated based on the formula:

[0027]

[0028] Among them, ρ is the strength data of the tunnel, M g is the total steel mass used in the tunnel structure, M h Total concrete mass used for the tunnel structure;

[0029] The specific logic for collecting the stiffness data of the tunnel structure is as follows:

[0030]

[0031] Where σ is the average elastic modulus of the steel and concrete used in the tunnel structure, EM g is the average elastic modulus of the steel type used in the tunnel structure, EM h The average elastic modulus of the concrete type used for the tunnel structure;

[0032]

[0033] Where τ is the average Poisson’s ratio of the steel and concrete used in the tunnel structure, PR g is the average Poisson’s ratio of the steel types used in the tunnel structure, PR h The average Poisson's ratio of the type of concrete used for the tunnel structure;

[0034] Pressure sensors are embedded at equal distances in the soil at the bottom and side walls of the tunnel, and the average soil pressure is calculated:

[0035]

[0036] in, is the average soil pressure, m is the number of soil pressure sensors, P t,j is the reading of the jth sensor;

[0037] Pressure sensors are installed equidistantly on the top and side walls of the tunnel and at different depths underwater, and the seawater pressure is calculated using the weighted average method:

[0038]

[0039] Among them, P w is the seawater pressure, w k is the depth weighting coefficient, P w,k is the reading of the kth sensor, and u is the number of pressure sensors;

[0040] Depth weighting factor w k The method of determining is:

[0041]

[0042] Among them, w k is the depth weighting coefficient, h k is the depth of the kth sensor, i.e., the depth from the sea surface to the kth sensor location, and H is the maximum depth in the measurement area.

[0043] Furthermore, the formula for generating the first impact index is as follows:

[0044]

[0045] Among them, A is the first impact index, is the average soil pressure, P wis the seawater pressure, ρ is the strength data of the tunnel, σ is the average elastic modulus of the steel and concrete used in the tunnel structure, τ is the average Poisson's ratio of the steel and concrete used in the tunnel structure, μ and β are preset proportional coefficients, and μ>γ>0, C1 is the first constant correction index;

[0046] The formula for generating the second impact index is as follows:

[0047]

[0048] Among them, B is the second influence index, u is the displacement data, ∈ is the strain, ü is the acceleration, α is the preset proportional coefficient, and C2 is the second constant correction index.

[0049] Furthermore, the first influence index and the second influence index are integrated, and correlation analysis is performed to calculate the comprehensive deformation index, and the formula based on which is:

[0050] QS=ψ*A+η*B+C3

[0051] Among them, QS is the comprehensive deformation index, A is the first influence index, B is the second influence index, ψ and η are preset proportional coefficients, and ψ>η>0, C3 is the third constant correction coefficient.

[0052] Furthermore, the specific logic for calculating the temperature compensation term is as follows:

[0053] Monitor the tunnel ambient temperature in real time, denoted as T, and calculate the temperature compensation term:

[0054] ΔD temp =α*(TT 0 )*L 0

[0055] Where, ΔD temp is the temperature compensation term, α is the linear expansion coefficient, the specific value depends on the material type, T is the real-time temperature of the tunnel, T 0 is the reference temperature, set according to the specific situation, L 0 is the initial length of the tunnel;

[0056] The temperature compensation term is incorporated into the comprehensive deformation index to calculate the corrected deformation of the submarine tunnel according to the following formula:

[0057]

[0058] Where, ΔD total is the predicted deformation of the submarine tunnel, QS is the comprehensive deformation index, υ is the preset proportional coefficient, ΔD temp is the temperature compensation term, and C4 is the fourth constant correction index.

[0059] Compared with the prior art, the present invention has the following beneficial effects:

[0060] The present invention can effectively solve the shortcomings of traditional prediction methods in complex seismic environments by constructing a fluid-structure-soil coupling model, and provide a more accurate deformation prediction. The comprehensive deformation index calculated by comprehensively analyzing the first influence index and the second influence index can fully reflect the actual deformation of the tunnel under the action of the earthquake. At the same time, the addition of real-time temperature compensation terms makes the prediction results more reliable and more adaptable. Finally, regular model calibration and comparison with actual monitoring data not only verifies the accuracy of the model, but also provides a scientific basis for the safe operation of the submarine tunnel and reduces potential safety risks. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Figure 1 It is a schematic diagram of the overall method flow of the present invention. DETAILED DESCRIPTION

[0062] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments.

[0063] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. The words "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0064] Example:

[0065] See also Figure 1 , the present invention provides a technical solution:

[0066] A method for predicting deformation of a submarine tunnel under earthquake action, comprising the following specific steps:

[0067] Step 1: construct a fluid-structure-soil coupling model based on the finite element simulation method to simulate the complex environment under the action of an earthquake; apply seismic waves to the constructed fluid-structure-soil coupling model to simulate the impact of earthquake propagation on the soil and the tunnel, set dynamic analysis parameters in the finite element software, start dynamic analysis, and record the dynamic parameters of the model, which are displacement, strain and acceleration data of the model;

[0068] In this embodiment, the specific logic of constructing the fluid-structure-soil coupling model based on the finite element simulation method is as follows:

[0069] An initial finite element model is established using ABAQUS software through component and assembly modules, and the physical and mechanical properties of the soil and tunnel structure are defined, which are elastic modulus, Poisson's ratio, density and shear strength. The flow characteristics of seawater are defined, which are the viscosity and density of seawater. The geometric model is divided into several small units to form a grid, and three-dimensional hexahedral units are selected to improve the calculation accuracy. The grid is refined around the tunnel to improve the accuracy of the calculation. The boundary conditions between the tunnel and the seawater are set at both ends of the tunnel. By applying seismic waves as dynamic loads, the environmental changes under the action of earthquakes are simulated. The simulation program is run to perform dynamic analysis of the model and obtain the dynamic parameters of the model, which are displacement, stress, strain and acceleration.

[0070] The specific logic of the process of obtaining the model dynamic parameters is as follows:

[0071] During dynamic analysis, the equations of motion are solved by the finite element method:

[0072]

[0073] Among them, N is the mass matrix, describing the mass distribution of the system, u is the displacement vector, representing the displacement of each node in the system, C is the damping matrix, describing the damping characteristics of the system, K is the stiffness matrix, describing the stiffness distribution of the system, and F(t) is the force caused by the seismic wave, expressed as a time-dependent function;

[0074] By solving the above equation, we can obtain the node displacement u(t) at each time step, and by performing time differentiation on the displacement, we can obtain the velocity By differentiating the velocity with respect to time, we can obtain the acceleration ü(t):

[0075]

[0076] Calculate strain data using the stress-strain relationship:

[0077]

[0078] Where ∈ is the strain, L represents the original length of the structure, and Δu is the change in displacement, i.e., the change from the initial length.

[0079] Step 1 can fully simulate the mutual influence between soil and submarine tunnel in complex environment under earthquake by constructing fluid-structure-soil coupling model, taking into account the coupling between fluid and solid. This method can more realistically reflect the behavior of tunnel under dynamic load and provide accurate data basis for subsequent analysis. Compared with the existing technology, this step has higher simulation accuracy and adaptability, and can handle a variety of complex factors, such as soil heterogeneity, seawater pressure and dynamic and static interactions, thereby improving the prediction ability of submarine tunnel deformation under earthquake and reducing the error caused by simplified assumptions. Using step 1, the overall scheme will obtain more realistic dynamic response data, which will improve the reliability of subsequent impact index generation, correlation analysis and deformation calculation. This comprehensive analysis can provide a scientific basis for the design and safety assessment of submarine tunnels, and further enhance the safety and economy of the project.

[0080] Step 2: Collecting environmental parameters and material parameters of the actual tunnel, wherein the environmental parameters are soil pressure data and seawater pressure data borne by the tunnel, and the material parameters are strength data and stiffness data of the tunnel; and generating a first impact index based on the dimensionless processed environmental parameters and material parameters, and generating a second impact index based on the dimensionless processed dynamic parameters;

[0081] In this embodiment, the process of collecting the environmental parameters and material parameters of the actual tunnel is specifically as follows:

[0082] The strength data is the ratio of the mass of steel bars and the mass of concrete used in the tunnel structure, and the stiffness data includes the average elastic modulus and average Poisson's ratio of the steel and concrete used in the tunnel structure;

[0083] The specific logic for collecting intensity data is:

[0084] The total concrete mass and total steel mass used to construct the tunnel structure are obtained, and the ratio of the steel mass to the concrete mass used in the tunnel structure is generated based on the formula:

[0085]

[0086] Among them, ρ is the strength data of the tunnel, M g is the total steel mass used in the tunnel structure, M h Total concrete mass used for the tunnel structure;

[0087] The specific logic for collecting the stiffness data of the tunnel structure is as follows:

[0088]

[0089] Where σ is the average elastic modulus of the steel and concrete used in the tunnel structure, EM g is the average elastic modulus of the steel type used in the tunnel structure, EM h The average elastic modulus of the concrete type used for the tunnel structure;

[0090]

[0091] Where τ is the average Poisson’s ratio of the steel and concrete used in the tunnel structure, PR g is the average Poisson’s ratio of the steel types used in the tunnel structure, PR h The average Poisson's ratio of the type of concrete used for the tunnel structure;

[0092] Pressure sensors are embedded at equal distances in the soil at the bottom and side walls of the tunnel, and the average soil pressure is calculated:

[0093]

[0094] in, is the average soil pressure, m is the number of soil pressure sensors, P t,j is the reading of the jth sensor;

[0095] Pressure sensors are installed equidistantly on the top and side walls of the tunnel and at different depths underwater, and the seawater pressure is calculated using the weighted average method:

[0096]

[0097] Among them, P w is the seawater pressure, w k is the depth weighting coefficient, P w,k is the reading of the kth sensor, and u is the number of pressure sensors;

[0098] Depth weighting factor w k The method of determining is:

[0099]

[0100] Among them, w k is the depth weighting coefficient, h k is the depth of the kth sensor, i.e., the depth from the sea surface to the kth sensor location, and H is the maximum depth in the measurement area.

[0101] The formula for generating the first impact index is as follows:

[0102]

[0103] Among them, A is the first impact index, is the average soil pressure, P w is the seawater pressure, ρ is the strength data of the tunnel, σ is the average elastic modulus of the steel and concrete used in the tunnel structure, τ is the average Poisson's ratio of the steel and concrete used in the tunnel structure, μ and γ are preset proportional coefficients, and μ>γ>0. This is because the seawater pressure and soil pressure are the main external loads borne by the tunnel, which have a direct and significant impact on the deformation and stability of the tunnel. Under the action of an earthquake, these pressures will change significantly, thus having a decisive impact on the overall structure of the tunnel. C1 is the first constant correction exponent; when the soil pressure or seawater pressure borne by the tunnel increases, the stress inside the tunnel material will increase, which may cause material fatigue or cracks. As the stress concentrates, higher stress concentration may occur in local areas, thereby increasing the risk of damage. Therefore, when or P w When ρ or σ increases, the first influence index A will decrease; when ρ or σ increases, it means that the stiffness of the tunnel is greater and its structure is stronger, so the first influence index A increases; when τ increases, it means that the Poisson's ratio of the material is larger, which means that it is more likely to deform when subjected to force, so A decreases; that is, ρ, σ and A are positively correlated, P w , τ and A are negatively correlated.

[0104] The formula for generating the second impact index is as follows:

[0105]

[0106] Among them, B is the second influence index, u is the displacement data, ∈ is the strain, ü is the acceleration, α is the preset proportional coefficient, and C2 is the second constant correction index; the increase in displacement means that the tunnel has experienced greater deformation, which may lead to local structural failure or decreased overall stability. Therefore, when u increases, the second influence index B decreases; strain indicates the degree of deformation of the material under the action of external force. With the increase of strain, the tunnel material may enter the plastic deformation stage, causing structural fatigue and damage, affecting its long-term stability and bearing capacity, so when ∈ increases, the second influence index B decreases; acceleration is the instantaneous rate of change under earthquake action, reflecting the response characteristics of the tunnel under dynamic load. Larger acceleration may lead to stronger vibration, thereby exacerbating displacement and strain, so when ü increases, the second influence index B decreases; that is, u, ∈, ü and B are negatively correlated.

[0107] Step 3: Combine the first influence index and the second influence index, perform correlation analysis, and calculate the comprehensive deformation index; monitor the tunnel ambient temperature in real time, incorporate the temperature compensation item into the comprehensive deformation index, and calculate the corrected deformation of the submarine tunnel;

[0108] In this embodiment, the first influence index and the second influence index are integrated to perform correlation analysis to calculate the comprehensive deformation index, and the formula used is:

[0109] QS=ψ*A+η*B+C3

[0110] Among them, QS is the comprehensive deformation index, A is the first influence index, B is the second influence index, ψ and η are preset proportional coefficients, and ψ>η>0, because environmental parameters and material parameters directly affect the bearing capacity and stability of the tunnel. These parameters determine the external loads borne by the tunnel under the action of earthquakes and directly affect its deformation and failure mode; C3 is the third constant correction coefficient. When A or B increases, QS increases accordingly, which means that A, B and QS are positively correlated.

[0111] The specific logic for calculating the temperature compensation term is as follows:

[0112] Monitor the tunnel ambient temperature in real time, denoted as T, and calculate the temperature compensation term:

[0113] ΔD temp =α*(TT 0 )*L 0

[0114] Where, ΔD temp is the temperature compensation term, α is the linear expansion coefficient, the specific value depends on the material type, T is the real-time temperature of the tunnel, T 0 is the reference temperature, which can be set according to the specific situation. For example, the value can be 25℃, L 0 is the initial length of the tunnel;

[0115] The temperature compensation term is incorporated into the comprehensive deformation index to calculate the corrected deformation of the submarine tunnel according to the following formula:

[0116]

[0117] Where, ΔD total is the predicted deformation of the submarine tunnel, QS is the comprehensive deformation index, υ is the preset proportional coefficient, ΔD temp is the temperature compensation term, and C4 is the fourth constant correction index.

[0118] Step 3 combines the first influence index and the second influence index to conduct correlation analysis, which can effectively integrate environmental parameters and dynamic response data to obtain a comprehensive deformation index. This method provides a comprehensive perspective, making it possible to accurately predict tunnel deformation in a complex environment. By introducing a temperature compensation item for real-time monitoring, the accuracy of the prediction can be further improved to ensure effectiveness under variable conditions. Compared with the prior art, step 3 not only improves the accuracy of deformation prediction, but also enhances the adaptability of the model and can better cope with changes in actual working conditions. Existing methods often analyze each parameter separately, while the ability to comprehensively analyze different influencing factors can effectively reduce prediction errors, improve safety and reliability, and thus have higher practical value in engineering applications. In this patent solution, the use of step 3 can add an important layer of safety to the overall solution.

[0119] Step 4: Regularly compare the model results with the actual monitoring data, perform model calibration, and verify the accuracy of the model.

[0120] In this embodiment, the model is corrected and verified by regularly comparing the model results with the actual monitoring data. This feedback mechanism ensures the accuracy and reliability of the model, making the prediction results more valuable for practical applications. At the same time, it can timely identify the gap between the model and the actual situation, and promote the continuous optimization of the model to adapt to the changing environmental conditions. Compared with the prior art, the advantage of step 4 is that a dynamic correction mechanism is introduced, so that the prediction model is not just a static calculation tool, but an intelligent system that can self-optimize and adjust.

[0121] The specific values ​​of α, γ, μ, η and ψ in the formula are generally determined by technical personnel in this field according to actual conditions. The technical personnel in this field collect multiple groups of sample data, and set corresponding preset proportional coefficients for each group of sample data. The preset proportional coefficients and the collected sample data are substituted into the formula. Through repeated experiments and parameter adjustments, the accuracy of the model output and the rationality of the results are observed, and these factor coefficients are gradually adjusted. The performance and effect of the model under different parameter settings are compared to find the optimal coefficient combination. The calculated factor coefficients are screened and averaged to obtain the values ​​of α, γ, μ, η and ψ.

[0122] In addition, the size of the preset factor coefficient is to quantify each parameter to obtain a specific value. In order to facilitate subsequent comparison, the size of the coefficient depends on the amount of sample data and the preset proportional coefficient initially set by technical personnel in this field for each set of sample data. It is not unique as long as it does not affect the proportional relationship between the parameter and the quantized value.

[0123] The above formulas are all dimensionless and numerical calculations. The formula is a formula for the most recent real situation obtained by collecting a large amount of data and performing software simulation. The preset parameters in the formula are set by technicians in this field according to actual conditions.

[0124] The above embodiments may be implemented in whole or in part by software, hardware, firmware or any other combination thereof. When implemented by software, the above embodiments may be implemented in whole or in part in the form of a computer program product. Those skilled in the art may appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein may be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed by hardware or software methods depends on the specific application and design constraints of the technical solution.

[0125] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, and may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0126] The above description is only a specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application.

Claims

1. A method for predicting deformation of a submarine tunnel under earthquake action, characterized in that: The specific steps include: Step 1: construct a fluid-structure-soil coupling model based on the finite element simulation method to simulate the complex environment under the action of an earthquake; apply seismic waves to the constructed fluid-structure-soil coupling model to simulate the impact of earthquake propagation on the soil and the tunnel, set dynamic analysis parameters in the finite element software, start dynamic analysis, and record the dynamic parameters of the model, which are displacement, strain and acceleration data of the model; Step 2: Collecting environmental parameters and material parameters of the actual tunnel, wherein the environmental parameters are soil pressure data and seawater pressure data borne by the tunnel, and the material parameters are strength data and stiffness data of the tunnel; and generating a first impact index based on the dimensionless processed environmental parameters and material parameters, and generating a second impact index based on the dimensionless processed dynamic parameters; Step 3: Combine the first influence index and the second influence index, perform correlation analysis, and calculate the comprehensive deformation index; monitor the tunnel ambient temperature in real time, incorporate the temperature compensation item into the comprehensive deformation index, and calculate the corrected deformation of the submarine tunnel; Step 4: Regularly compare the model results with the actual monitoring data, perform model calibration, and verify the accuracy of the model; The formula for generating the first impact index is as follows: Among them, A is the first impact index, is the average soil pressure, P w is the seawater pressure, ρ is the strength data of the tunnel, σ is the average elastic modulus of the steel and concrete used in the tunnel structure, τ is the average Poisson's ratio of the steel and concrete used in the tunnel structure, μ and γ are preset proportional coefficients, and μ>γ>0, C1 is the first constant correction index; The formula for generating the second impact index is as follows: Wherein, B is the second influence index, u is the displacement data, ∈ is the strain, ü is the acceleration, α is the preset proportional coefficient, and C2 is the second constant correction index; The first influence index and the second influence index are combined to perform correlation analysis to calculate the comprehensive deformation index, and the formula is: QS=ψ*A+η*B+C3 Wherein, QS is the comprehensive deformation index, A is the first influence index, B is the second influence index, ψ and η are preset proportional coefficients, and ψ>η>0, and C3 is the third constant correction coefficient; The specific logic for calculating the temperature compensation term is as follows: Monitor the tunnel ambient temperature in real time, denoted as T, and calculate the temperature compensation term: ΔD temp =α*(T-T0)*L0 Where, ΔD temp is the temperature compensation term, α is the linear expansion coefficient, the specific value depends on the material type, T is the real-time temperature of the tunnel, T0 is the reference temperature, which is set according to the specific situation, and L0 is the initial length of the tunnel; The temperature compensation term is incorporated into the comprehensive deformation index to calculate the corrected deformation of the submarine tunnel according to the following formula: Where, ΔD total is the predicted deformation of the submarine tunnel, QS is the comprehensive deformation index, υ is the preset proportional coefficient, ΔD temp is the temperature compensation term, and C4 is the fourth constant correction index.

2. The method for predicting deformation of a submarine tunnel under earthquake action according to claim 1, characterized in that: The specific logic of constructing the fluid-structure-soil coupling model based on the finite element simulation method is as follows: An initial finite element model is established using ABAQUS software through component and assembly modules, and the physical and mechanical properties of the soil and tunnel structure are defined, which are elastic modulus, Poisson's ratio, density and shear strength. The flow characteristics of seawater are defined, which are the viscosity and density of seawater. The geometric model is divided into several small units to form a grid, and three-dimensional hexahedral units are selected to improve the calculation accuracy. The grid is refined around the tunnel to improve the accuracy of the calculation. The boundary conditions between the tunnel and the seawater are set at both ends of the tunnel. By applying seismic waves as dynamic loads, the environmental changes under the action of earthquakes are simulated. The simulation program is run to perform dynamic analysis of the model and obtain the dynamic parameters of the model, which are displacement, stress, strain and acceleration.

3. The method for predicting deformation of a submarine tunnel under earthquake action according to claim 2, characterized in that: The specific logic of the process of obtaining the model dynamic parameters is as follows: During dynamic analysis, the equations of motion are solved by the finite element method: Among them, N is the mass matrix, describing the mass distribution of the system, u is the displacement vector, representing the displacement of each node in the system, C is the damping matrix, describing the damping characteristics of the system, K is the stiffness matrix, describing the stiffness distribution of the system, and F(t) is the force caused by the seismic wave, expressed as a time-dependent function; By solving the above equation, we can obtain the node displacement u(t) at each time step, and by performing time differentiation on the displacement, we can obtain the velocity By differentiating the velocity with respect to time, we can obtain the acceleration Calculate strain data using the stress-strain relationship: Among them, ∈ is the strain, L represents the original length of the structure, and Δu is the displacement change.

4. The method for predicting deformation of a submarine tunnel under earthquake action according to claim 1, characterized in that: The process of collecting the environmental parameters and material parameters of the actual tunnel is specifically as follows: The strength data is the ratio of the mass of steel bars and the mass of concrete used in the tunnel structure, and the stiffness data includes the average elastic modulus and average Poisson's ratio of the steel and concrete used in the tunnel structure; The specific logic for collecting intensity data is: The total concrete mass and total steel mass used to construct the tunnel structure are obtained, and the ratio of the steel mass to the concrete mass used in the tunnel structure is generated based on the formula: Among them, ρ is the strength data of the tunnel, M g is the total steel mass used in the tunnel structure, M h Total concrete mass used for the tunnel structure; The specific logic for collecting the stiffness data of the tunnel structure is as follows: Where σ is the average elastic modulus of the steel and concrete used in the tunnel structure, EM g is the average elastic modulus of the steel type used in the tunnel structure, EM h The average elastic modulus of the concrete type used for the tunnel structure; Where τ is the average Poisson’s ratio of the steel and concrete used in the tunnel structure, PR g is the average Poisson’s ratio of the steel types used in the tunnel structure, PR h The average Poisson's ratio of the type of concrete used for the tunnel structure; Pressure sensors are embedded at equal distances in the soil at the bottom and side walls of the tunnel, and the average soil pressure is calculated: in, is the average soil pressure, m is the number of soil pressure sensors, P t,j is the reading of the jth sensor; Pressure sensors are installed equidistantly on the top and side walls of the tunnel and at different depths underwater, and the seawater pressure is calculated using the weighted average method: Among them, P w is the seawater pressure, w k is the depth weighting coefficient, P w,k is the reading of the kth sensor, and u is the number of pressure sensors; Depth weighting factor w k The method of determining is: Among them, w k is the depth weighting coefficient, h k is the depth of the kth sensor, i.e., the depth from the sea surface to the kth sensor location, and H is the maximum depth in the measurement area.

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