A railway double-track tunnel floor rise prediction method, system, terminal and medium

Abstract

The present invention discloses a method, system, terminal, and medium for predicting floor heave of a double-track railway tunnel, relating to the field of tunnel engineering technology. The method solves the current problem of a lack of active prediction of the deformation resistance of the tunnel bottom structure, which often results in low reliability and safety of surrounding rock tunnel construction due to excessive deformation of the bottom structure. The key points of the technical solution are as follows: using engineering parameters to establish a corresponding engineering model, and based on the engineering model, establishing a correlation model; when the stress release rate is released from the initial value of the stress release rate to the maximum value, the floor heave deformation of the inverted arch filling layer of the to-be-built project is calculated based on support parameters; if the floor heave deformation does not meet a threshold, the support parameters are adjusted until the floor heave deformation meets a threshold set. The method achieves the purpose of predicting the deformation resistance of the tunnel bottom structure and adjusting the design parameters of the bottom structure according to the prediction results, thereby reducing the risk of excessive deformation of the bottom structure and improving the reliability and safety of surrounding rock tunnel construction.

Description

Technical Field

[0001] The present invention relates to the technical field of tunnel engineering, and more particularly to a method, system, terminal and medium for predicting floor rise in a double-track railway tunnel. Background Art

[0002] Due to their large spans, double-track railway tunnels usually have relatively flat bottom structures. Under conditions of high ground stress and layered surrounding rock, the bottom structure often experiences bottom heave (upward bulging of the bottom structure), leading to upward displacement of structures such as the invert filling layer and track. When this displacement exceeds the maximum allowable value of the track, it will directly affect the track smoothness, thereby affecting the safety of train operation and forcing the train to slow down or even stop for repairs.

[0003] The primary cause of floor heave in double-track railway tunnels is a mismatch between the post-excavation bottom load and the deformation resistance of the bottom structure. Currently, there are more measures to address large deformations in tunnel bottom structures and passive monitoring and measurement, but there is a lack of research on active prediction methods for the deformation resistance of tunnel bottom structures. This poses significant challenges to the design and reinforcement of tunnel bottom structures, and the reliability and safety of surrounding rock tunnel construction often suffers due to excessive bottom structure deformation. Summary of the Invention

[0004] The purpose of the present invention is to provide a method, system, terminal and medium for predicting floor heave in a double-track railway tunnel. By predicting the deformation resistance of the tunnel bottom structure and adjusting the design parameters of the bottom structure based on the prediction results, the risk of excessive deformation of the bottom structure is reduced, thereby improving the reliability and safety of surrounding rock tunnel construction.

[0005] The above technical objectives of the present invention are achieved through the following technical solutions:

[0006] A method for predicting floor rise in a double-track railway tunnel comprises the following steps:

[0007] S1. Based on the engineering parameters of the project to be built, establish an engineering model corresponding to the project to be built;

[0008] S2. Constructing a correlation model between the stress release rate of the project to be built and the bottom uplift deformation of the project to be built in the engineering model;

[0009] S3. Obtaining the support parameters of the project to be built and the initial value of the stress release rate when the growth rate of the correlation model curve is a critical value;

[0010] S4. When the stress release rate of the project to be built is released from the initial stress release rate to the maximum stress release rate, the bottom uplift deformation of the inverted arch filling layer of the project to be built is calculated based on the support parameters;

[0011] S5. If the bottom bulge deformation does not meet the threshold value, adjust the support parameters and repeat step S4 until the bottom bulge deformation meets the threshold value set, and obtain the adjusted support parameters.

[0012] Furthermore, the engineering parameters include elastic modulus, cohesion, internal friction angle, Poisson's ratio, and ground stress value.

[0013] Furthermore, based on the engineering parameters, using ANSYS Simulation calculation software is used to establish the engineering model.

[0014] Furthermore, the construction process of the association model is specifically as follows:

[0015] Obtaining a release value of a stress release rate of the project to be constructed during a release process when the project to be constructed has no support, and a bottom heave deformation amount of the project to be constructed corresponding to the release value;

[0016] Based on the release value and the deformation of the bottom uplift of the project to be built, construct a corresponding stress release rate and deformation curve of the bottom uplift of the project to be built;

[0017] The curve is fitted with an exponential function to obtain the correlation model.

[0018] Furthermore, the association model is ,in, y is the bottom bulge deformation, x is the stress release rate, a 、 b are the curve fitting parameters of the association model.

[0019] Furthermore, when the second-order derivative of the correlation model is 1, the growth rate of the correlation model curve is a critical value.

[0020] Furthermore, in S5, the support parameter is adjusted to the invert curvature of the support parameter.

[0021] A railway double-track tunnel floor heave prediction system, comprising:

[0022] The first construction module is used to execute S1 to establish an engineering model corresponding to the project to be built based on the engineering parameters of the project to be built;

[0023] The second construction module is used to execute S2 to construct a correlation model between the stress release rate of the project to be built and the bottom uplift deformation of the project to be built in the engineering model;

[0024] An acquisition module, configured to execute S3, to acquire the support parameters of the project to be constructed and an initial value of the stress release rate when the growth rate of the correlation model curve is a critical value;

[0025] a calculation module, configured to execute S4, and calculate, based on the support parameters, a bottom uplift deformation of the inverted arch filling layer of the project to be constructed when the stress release rate of the project to be constructed is released from the initial stress release rate to the maximum stress release rate;

[0026] The identification module is used to execute S5. If the bottom uplift deformation does not meet the threshold value, the support parameters are adjusted and step S4 is repeated until the bottom uplift deformation meets the threshold value group, thereby obtaining the adjusted support parameters.

[0027] An electronic terminal comprises: a memory for storing a computer program; and a processor for executing the computer program stored in the memory, so that the electronic terminal executes the method for predicting floor rise of a double-track railway tunnel.

[0028] A computer-readable storage medium stores a computer program, which, when executed by a processor, implements a method for predicting floor rise in a double-track railway tunnel.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] ① Using the engineering parameters of the project to be built, a corresponding engineering model is established to facilitate the simulation of the relationship between the stress release rate of the project to be built and the deformation of the bottom heave of the project to be built through the engineering model.

[0031] ② Based on the engineering model, a correlation model between the stress release rate of the project to be built and the bottom uplift deformation of the project to be built is established, and the purpose of controlling the construction time of the bottom structure is achieved by determining the critical value of the growth rate of the correlation model curve.

[0032] ③ When the stress release rate of the project to be built is released from the initial stress release rate to the maximum stress release rate, the bottom uplift deformation of the invert arch filling layer of the project to be built is calculated based on the support parameters to achieve the purpose of predicting the deformation resistance of the tunnel bottom structure.

[0033] ④ If the bottom uplift deformation does not meet the threshold, the support parameters are adjusted until the bottom uplift deformation meets the threshold set, and the adjusted support parameters are obtained to achieve the purpose of adjusting the design parameters of the bottom structure according to the prediction results.

[0034] ⑤ Based on the support parameters, the bottom uplift deformation of the inverted arch filling layer of the proposed project is calculated. If the bottom uplift deformation does not meet the threshold, the support parameters are adjusted until the bottom uplift deformation meets the threshold. This achieves the goal of predicting the deformation resistance of the tunnel bottom structure and adjusting the bottom structure design parameters based on the prediction results, thereby reducing the risk of excessive bottom structure deformation and improving the reliability and safety of surrounding rock tunnel construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the drawings:

[0036] Figure 1 1 is a schematic flow chart of a method for predicting floor rise in a double-track railway tunnel according to an embodiment;

[0037] Figure 2 This is a schematic diagram of tunnel dimensions for a specific implementation case in the embodiment;

[0038] Figure 3 A schematic diagram of a tunnel corresponding calculation model for a specific implementation case in the embodiment;

[0039] Figure 4 This is a schematic diagram of the relationship between the stress release rate and the floor heave deformation value when the tunnel is unsupported in a specific implementation case in the embodiment;

[0040] Figure 5 This is a schematic diagram of the calculated deformation cloud diagram when the initial support parameter of the inverted arch curvature is 1 / 12 in a specific implementation case in the embodiment;

[0041] Figure 6 This is a schematic diagram of the calculated deformation cloud diagram when the inverted arch curvature of the initial support parameter is adjusted to 1 / 7.5 for a specific implementation case in the embodiment. DETAILED DESCRIPTION

[0042] 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 examples and drawings. The exemplary embodiments of the present invention and their descriptions are only used to explain the present invention and are not intended to limit the present invention.

[0043] Surrounding rock refers to the rock (soil) within a certain range around the tunnel that affects the stability of the tunnel body.

[0044] Embodiment: A method, system, terminal and medium for predicting floor heave in a double-track railway tunnel.

[0045] like Figure 1 As shown, a method for predicting floor rise in a double-track railway tunnel includes the following steps:

[0046] S1. Based on the engineering parameters of the project to be built, establish an engineering model corresponding to the project to be built; the engineering parameters include elastic modulus, cohesion, internal friction angle, Poisson's ratio, and ground stress value; based on the engineering parameters, use ANSYS Simulation calculation software is used to establish the engineering model, specifically:

[0047] By understanding the engineering conditions of the tunnel (project to be built), such as the tunnel cross-section shape and burial depth, and understanding the tunnel geological conditions, we can obtain the surrounding rock elastic modulus required for numerical simulation (building engineering models). E , cohesion c , internal friction angle φ , Poisson's ratio μ , ground stress value and other parameters, using ANSYS Numerical simulation calculation software and finite element software are used to establish a two-dimensional plane model. The model width and height are usually greater than 5 times the tunnel diameter. The tunnel is located in the middle of the model and is surrounded by rock and soil structures. Boundary conditions are applied on all sides of the model, with horizontal constraints on the left and right sides and a fixed constraint on the bottom. Vertical initial ground stress is applied on the top according to the tunnel burial depth. Different parameter values ​​are set for different materials such as surrounding rock and tunnel support structure in the calculation model to obtain a calculation model (engineering model) that conforms to the actual project.

[0048] S2. Construct a correlation model between the stress release rate of the project to be built and the deformation of the bottom heave of the project to be built (the amount of uplift of the tunnel bottom structure) in the engineering model; the construction process of the correlation model is specifically as follows: when the project to be built has no support, the release value of the stress release rate of the project to be built during the release process and the deformation of the bottom heave of the project to be built corresponding to the release value; based on the release value and the deformation of the bottom heave of the project to be built, construct a corresponding curve of the stress release rate of the project to be built and the deformation of the bottom heave of the project to be built; use an exponential function to fit the curve to obtain the correlation model, and the correlation model is ,in, y is the bottom bulge deformation, x is the stress release rate, a 、 b are the parameters of the curve fitting formula, specifically:

[0049] Simulate the stress release rate after tunnel excavation without any support. 0 Release to 100% The tunnel deformation value at that time was obtained, and the stress release rate and tunnel bottom deformation curve were obtained. The exponential function was used to fit the curve to obtain the fitting formula ,in, y is the bottom bulge deformation, x is the stress release rate, a 、 b is the parameter of the curve fitting formula. x Corresponding bottom bulge deformation y After that, the scatter plot is fitted to determine a and b The specific value of is used to obtain the specific fitting formula.

[0050] S3. Obtain the support parameters of the project to be built and the initial value of the stress release rate when the growth rate of the correlation model curve is a critical value; the second-order derivative of the correlation model is 1 When , the growth rate of the correlation model curve is a critical value, specifically:

[0051] By fitting the formula The second-order derivative of determines the inflection point of the growth rate of the curve, and sets the second-order derivative to 1 The curve growth rate at this time is the critical value, and the corresponding stress release rate is obtained. .

[0052] S4. When the stress release rate of the project to be built is released from the initial stress release rate to the maximum stress release rate, the bottom uplift deformation of the inverted arch filling layer of the project to be built is calculated based on the support parameters, specifically:

[0053] The two-step excavation corresponds to the tunnel construction sequence. The existing tunnel structure is divided into two layers: initial support and lining. After the tunnel is excavated, the initial support is first applied. The initial support is usually applied in the form of up and down step excavation. When the initial support is fully closed, the lining structure is applied according to the deformation situation. This embodiment deals with the bottom heave problem that occurs after the lining structure is applied. Therefore, the first step corresponds to the initial support application, and the second step corresponds to the lining application. The initial support parameters designed after the first step of excavation are simulated, and the stress release rate is taken as p , the calculation is completed; the second step is to continue to build the lining, and the stress release rate is from p Release to 100% , calculate the specific value of the bottom heave deformation of the tunnel invert filling layer surface U The bottom heave deformation is extracted from the software based on calculation. The calculation software can extract the deformation value of any position of the tunnel and surrounding rock structure under any stress release rate.

[0054] S5. If the floor uplift deformation does not meet the threshold, adjust the support parameters and repeat step S4 until the floor uplift deformation meets the threshold set, obtaining the adjusted support parameters; adjust the support parameters to the invert curvature of the support parameters, specifically:

[0055] Comparison of the bottom uplift deformation of the tunnel invert filling layer U With control value U0 (threshold), when the surface bottom deformation U ≤Control value U0 When the support parameter verification is passed; when the surface bottom deformation U >Control value U0When the support parameter verification fails, the parameters need to be adjusted and step S4 calculations need to be repeated until the support parameter verification passes and the final support parameters are obtained. During tunnel excavation, the surrounding rock will continuously release stress. Stress release is a time process, and tunnel construction is also related to time. Usually, when the rock mass is excavated, initial support is applied. At this time, the surrounding rock stress is continuously released. The initial support bears the load of the surrounding rock mass and continuously deforms. When the stress is released to a certain extent, the lining structure is applied. At this time, the surrounding rock stress is still being released. The initial support and lining jointly provide support force, and both will also have a certain deformation. When to apply the lining structure depends on factors such as the bearing capacity of the initial support, the construction space conditions, and the impact of stress release on the safety of the lining structure after the lining structure is applied. Therefore, it is necessary to fit the stress release curve and obtain the critical value of the curve growth rate as the application time. According to the verification results, the support parameters are adjusted to obtain appropriate parameters.

[0056] Specific implementation cases:

[0057] The speed of a tunnel is 300km Double-track tunnel, tunnel depth 200m , geological survey results show that the surrounding rock density 2100kg / m ³ , elastic modulus E=1.5GPa , cohesion c=200kPa , friction angle φ=25 °, Poisson's ratio μ=0.32 , lateral pressure coefficient K=1.5 , equivalent uniformly distributed stress at the top P=1.49MPa , span D=14.9m Specific tunnel dimensions are as follows: Figure 2 As shown, the corresponding calculation model is as follows Figure 3 As shown in the figure. Boundary conditions: horizontal constraints are applied on the left and right sides of the model, fixed constraints are applied on the bottom of the model, and vertical initial stress is applied on the upper surface of the model to replace the omitted upper rock mass to simulate high stress. The initial support of the tunnel is simulated by solid elements, and the preliminary design parameters are initial support 25cm thick C30 Shotcrete, the invert curvature is 1 / 12, and the lining is 40cm thick C35 Concrete, filling layer is C25 Concrete.

[0058] According to geological survey data and specifications, the relevant calculation parameters are shown in Table 1:

[0059]

[0060] Table 1

[0061] The calculation results without support are shown in Table 2:

[0062]

[0063] Table 2

[0064] The relationship between the stress release rate and the bottom heave deformation value without support is calculated as follows: Figure 4 As shown, the exponential function is used to fit the curve to obtain the fitting formula , determine the inflection point of the curve growth rate by the second-order derivative of the fitting formula, and set the second-order derivative to 1 The curve growth rate at this time is the critical value, and the corresponding stress release rate is obtained. .

[0065] Re-simulate the excavation, and apply the designed initial support parameters after the first step of excavation. 25cm thick C30 Sprayed concrete, the inverted arch curvature is 1 / 12, the stress release rate p=79.02 ( % ), the calculation is completed; the second step is to continue to build the lining, 40cm thick C35 Concrete, filling layer is C25 Concrete, stress release rate from p Release to 100% , calculate the bottom uplift deformation of the tunnel invert filling layer surface U=3.3mm , the calculated deformation cloud is as follows Figure 5 shown.

[0066] based on" 250~350km / h The permissible deviation management value of the static geometric dimensions of the track is stipulated in the "Control Value of the Filling Layer of the Tunnel Invert" U0 Select the value for regular track maintenance 60% , which is 2.4mm .

[0067] Comparison of the bottom uplift deformation of the tunnel invert filling layer U With control value U0 The relationship between the surface bottom deformation and U >Control value U0 , the support parameter verification fails and the parameters need to be adjusted and recalculated.

[0068] The adjusted parameters are the initial support 25cm thick C30 Shotcrete, the invert curvature is 1 / 7.5, and the lining is 40cm thick C35 Concrete, filling layer is C25 Concrete. Calculate the bottom heave deformation of the tunnel invert filling layer surface U=1.5mm <Control value U0=2.4mm , the support parameter verification is passed, and the calculated deformation cloud diagram is as follows Figure 6 shown.

[0069] This embodiment also provides a railway double-track tunnel floor uplift prediction system, comprising: a first construction module, configured to execute S1, to establish an engineering model corresponding to the project to be constructed based on the engineering parameters of the project to be constructed; a second construction module, configured to execute S2, to construct a correlation model between the stress release rate of the project to be constructed and the floor uplift deformation of the project to be constructed in the engineering model; an acquisition module, configured to execute S3, to obtain the support parameters of the project to be constructed and the initial value of the stress release rate when the growth rate of the correlation model curve is a critical value; a calculation module, configured to execute S4, to calculate the floor uplift deformation of the inverted arch filling layer of the project to be constructed based on the support parameters when the stress release rate of the project to be constructed is released from the initial value of the stress release rate to the maximum value of the stress release rate; and an identification module, configured to execute S5, to adjust the support parameters if the floor uplift deformation does not meet the threshold value, and to repeat step S4 until the floor uplift deformation meets the threshold value group, thereby obtaining the adjusted support parameters.

[0070] This embodiment also provides an electronic terminal, comprising: a memory, the memory being used to store a computer program; and a processor, the processor being used to execute the computer program stored in the memory, so that the electronic terminal executes the method for predicting floor rise in a double-track railway tunnel.

[0071] This embodiment also provides a computer-readable storage medium, on which a computer program is stored. When the program is executed by a processor, the method for predicting floor rise of a double-track railway tunnel is implemented.

[0072] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for predicting floor rise in a double-track railway tunnel, characterized in that: The following steps are involved: S1. Based on the engineering parameters of the project to be constructed, a two-dimensional plane model is created, with the tunnel located in the center of the two-dimensional plane model, surrounded by the rock and soil structure. Boundary conditions are applied on all sides, with horizontal constraints on the left and right sides and a fixed constraint at the bottom, to obtain an engineering model corresponding to the project to be constructed; S2. Constructing a correlation model between the stress release rate of the project to be built and the deformation of the bottom uplift of the project to be built in the engineering model, including: Obtaining a release value of a stress release rate of the project to be constructed during a release process when the project to be constructed has no support, and a bottom heave deformation amount of the project to be constructed corresponding to the release value; Based on the release value and the deformation of the bottom heave of the project to be built, constructing a corresponding stress release rate and deformation curve of the bottom heave of the project to be built; Fitting the curve using an exponential function to obtain the correlation model; When the second-order derivative of the correlation model is 1, the growth rate of the correlation model curve is a critical value; S3. Obtaining the initial value of the stress release rate when the support parameters of the project to be built and the curve growth rate of the correlation model are critical; S4. When the stress release rate of the project to be built is released from the initial stress release rate to the maximum stress release rate, the bottom uplift deformation of the inverted arch filling layer of the project to be built is calculated based on the support parameters; S5. If the bottom bulge deformation does not meet the threshold value, adjust the support parameters and repeat step S4 until the bottom bulge deformation meets the threshold value set, and obtain the adjusted support parameters.

2. The method for predicting floor rise in a double-track railway tunnel according to claim 1, characterized in that: The engineering parameters include elastic modulus, cohesion, internal friction angle, Poisson's ratio, and ground stress value.

3. The method for predicting floor rise in a double-track railway tunnel according to claim 1, wherein: Based on the engineering parameters, using ANSYS Simulation calculation software is used to establish the engineering model.

4. The method for predicting floor rise in a double-track railway tunnel according to claim 1, wherein: The association model is ,in, y is the bottom bulge deformation, x is the stress release rate, a 、 b are the curve fitting parameters of the association model.

5. The method for predicting floor rise in a double-track railway tunnel according to claim 1, characterized in that: In S5, the support parameter is adjusted to the invert curvature of the support parameter.

6. A railway double-track tunnel floor rise prediction system, characterized in that: The system is used to execute the railway double-track tunnel floor rise prediction method according to any one of claims 1 to 5, and the system comprises: The first construction module is used to execute S1 to establish an engineering model corresponding to the project to be built based on the engineering parameters of the project to be built; The second construction module is used to execute S2 to construct a correlation model between the stress release rate of the project to be built and the bottom uplift deformation of the project to be built in the engineering model; An acquisition module, configured to execute S3, to acquire the support parameters of the project to be constructed and an initial value of the stress release rate when the growth rate of the correlation model curve is a critical value; a calculation module, configured to execute S4, and calculate, based on the support parameters, a bottom uplift deformation of the inverted arch filling layer of the project to be constructed when the stress release rate of the project to be constructed is released from the initial stress release rate to the maximum stress release rate; The identification module is used to execute S5. If the bottom uplift deformation does not meet the threshold value, the support parameters are adjusted and step S4 is repeated until the bottom uplift deformation meets the threshold value group, thereby obtaining the adjusted support parameters.

7. An electronic terminal, characterized in that: include: a memory for storing a computer program; A processor is used to execute the computer program stored in the memory so that the electronic terminal executes the railway double-track tunnel floor rise prediction method according to any one of claims 1 to 5.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, a method for predicting floor rise of a double-track railway tunnel according to any one of claims 1 to 5 is implemented.

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