A method for analyzing dynamic response of prefabricated pipe gallery structure under train operation

Abstract

The application provides a prefabricated pipe gallery structure dynamic response analysis method under train operation, belongs to the field of structure vibration numerical simulation, constructs a prefabricated pipe gallery coupling finite element model under a soft soil foundation, and establishes a bridge pier foundation model in the prefabricated pipe gallery coupling finite element model; the boundary conditions of the prefabricated pipe gallery coupling finite element model are defined; the static analysis and modal analysis of the prefabricated pipe gallery are carried out based on the boundary conditions; a train-ballasted track-bridge dynamic coupling finite element model is established, and the X-direction and Y-direction support reaction time history response signals of the bottom of the bridge pier when the train is running are extracted according to the model; on the basis of the static analysis and modal analysis of the prefabricated pipe gallery, the support reaction time history response signals are input into the bridge pier foundation model, the dynamic response analysis of the prefabricated pipe gallery structure under the soft soil foundation is carried out, and the dynamic response result of the prefabricated pipe gallery structure under the train operation is obtained. The method combines the static analysis and the dynamic response, and completes the dynamic response analysis under the real-time train operation.

Description

Technical Field

[0001] The present invention belongs to the technical field of structural vibration numerical simulation, and in particular relates to a method for analyzing the dynamic response of a prefabricated pipe gallery structure under train operation. Background Art

[0002] Underground utility corridors are tunnel-like structures with high overall rigidity and disaster resistance. The construction of cross-line utility corridor tunnels avoids traffic congestion, environmental pollution, and economic waste associated with subsequent pipeline construction, contributing to the planning and management of new cities and their future sustainable development.

[0003] Under the influence of vehicle loads, pipeline corridors must withstand the vibration loads brought by vehicles, which are also transmitted to the foundation and surrounding soil. Soft soil foundations cause surface settlement, affecting the overall stability of pipeline corridors and tunnels. The impact of train vibration on prefabricated pipeline corridors crossing tracks under soft soil foundations is even more significant. Therefore, it is of great significance to study the failure modes of pipeline corridors crossing tracks under train loads.

[0004] Vehicle loads can cause significant uneven settlement of tunnels on soft soil foundations. Prefabricated tunnels are prone to joint failure at their connections, causing structural cracks and water leakage. Train vibrations negatively impact the surrounding environment, while the complex underground spatial structure further complicates the research task. Existing research primarily uses numerical models to statically analyze tunnel structures under vehicle loads. However, limited research examines the dynamic response of tunnel structures to train vibrations. Furthermore, limitations exist in accurately simulating the train-foundation-tunnel-pipeline relationship, making it difficult to accurately and real-time simulate the dynamic response of tunnels under train operation. Summary of the Invention

[0005] In order to overcome the above-mentioned deficiencies in the prior art, the present invention provides a method for analyzing the dynamic response of a prefabricated pipe gallery structure under train operation.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] A method for analyzing the dynamic response of a prefabricated pipe gallery structure under train operation includes the following steps:

[0008] Constructing a coupled finite element model of a prefabricated pipe gallery under a soft soil foundation, and establishing a pier foundation model at a corresponding position in the coupled finite element model of the prefabricated pipe gallery;

[0009] Defining boundary conditions of the prefabricated pipe gallery coupled finite element model;

[0010] Performing static analysis and modal analysis of the prefabricated pipe gallery based on the boundary conditions;

[0011] A train-ballasted track-bridge dynamic coupling finite element model was established, and the time-history response signals of the X- and Y-direction support reactions at the bottom of the bridge piers during train operation were extracted based on this model.

[0012] Based on the static and modal analysis of the prefabricated pipe gallery, the support reaction time-history response signal is input into the pier foundation model to conduct a dynamic response analysis of the prefabricated pipe gallery structure under soft soil foundation, and the dynamic response results of the prefabricated pipe gallery structure under train operation are obtained.

[0013] Preferably, constructing a coupled finite element model of a prefabricated pipe gallery under a soft soil foundation specifically includes:

[0014] Set contact units between pipe segments of the prefabricated pipe gallery and determine the calculation domain and material parameters of the prefabricated pipe gallery;

[0015] Establishing a prefabricated pipe gallery structure finite element model, a soft soil foundation finite element model, and a pipeline finite element model based on the calculation domain and material parameters;

[0016] A coupled finite element model of the prefabricated pipe gallery under the soft soil foundation is generated according to the finite element model of the prefabricated pipe gallery structure, the finite element model of the soft soil foundation and the finite element model of the pipeline.

[0017] Preferably, the establishing of the prefabricated pipe gallery structure finite element model, the soft soil foundation finite element model and the pipeline finite element model specifically includes:

[0018] Utilizing existing support structure design methods, the 3D structure of the prefabricated pipe gallery, soft soil foundation, and pipelines was established using ANSYS finite element analysis software.

[0019] Based on the three-dimensional structure and combined with parametric language, the finite element model of the prefabricated pipeline corridor structure, the finite element model of the soft soil foundation and the finite element model of the pipeline are established.

[0020] Preferably, the finite element model of the prefabricated pipe gallery structure includes the pipe gallery, GIL bracket, GIL pipeline, and raft-CFG pile composite foundation.

[0021] Preferably, the calculation domain, material parameters and boundary conditions are defined in ANSYS finite element analysis software;

[0022] The material parameters include elastic modulus, Poisson's ratio, and density;

[0023] The boundary conditions are: applying full Y-direction constraint to the bottom of the whole model, applying X-direction constraint to the horizontal direction, and applying Z-direction constraint to the vertical direction;

[0024] The calculation domain refers to the foundation depth of the calculation model. When there is no adjacent load influence and the foundation width is 1-30 m, the foundation depth of the model at the midpoint of the foundation is calculated according to formula (1):

[0025] (1)

[0026] Where: b is the width of the foundation, m.

[0027] Preferably, in the finite element model of the prefabricated pipe gallery structure, the soft soil layer, pipe gallery and raft-CFG pile composite foundation are all simulated using Solid 186 units; Beam 188 beam units are used to simulate the GIL bracket and GIL pipeline; contact units are used for the joints between each pipe joint, and the model grid is divided into hexahedral units.

[0028] Preferably, the static analysis and modal analysis of the prefabricated pipe gallery are performed based on the boundary conditions to obtain the first 30 modal frequencies of the prefabricated pipe gallery structure.

[0029] Preferably, there are two pier foundation models, and the step of inputting the support reaction time-history response signal into the pier foundation model to perform a dynamic response analysis of the prefabricated pipeline corridor structure under a soft soil foundation is specifically as follows: the reaction time-history signal is simultaneously applied to the foundation tops of the two pier foundation models to perform a dynamic response analysis of the overall pipeline corridor structure.

[0030] The method for analyzing the dynamic response of a prefabricated pipe gallery structure under train operation provided by the present invention has the following beneficial effects:

[0031] The present invention first constructs a prefabricated pipe gallery coupling finite element model under a soft soil foundation and a train-ballasted track-bridge dynamic coupling finite element model; the static analysis and modal analysis of the prefabricated pipe gallery are performed through the prefabricated pipe gallery coupling finite element model, and at the same time, the X-direction and Y-direction support reaction time-history response signals of the pier bottom during train operation are extracted through the train-ballasted track-bridge dynamic coupling finite element model, which are dynamic signals. Finally, the dynamic response analysis of the prefabricated pipe gallery structure under a soft soil foundation is performed through the support reaction time-history response signal, and the dynamic response analysis under real-time train operation is completed to obtain the internal force deformation characteristics of the prefabricated pipe gallery structure. This method can more accurately and in real time reflect the static and dynamic responses of the pipe gallery tunnel under train operation, thereby better exploring the damage mechanism of underground pipe galleries and transmission lines, and accordingly formulating corresponding measures to improve the vibration resistance of the line and ensure the safe operation of the pipe gallery structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] To more clearly illustrate the embodiments of the present invention and its design, the following briefly introduces the drawings required for this embodiment. The drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be derived from these drawings without inventive effort.

[0033] Figure 1This is a flow chart of the method for analyzing the dynamic response of a prefabricated pipe gallery structure under train operation provided by the present invention;

[0034] Figure 2 Flowchart of the method for analyzing the dynamic response of a prefabricated pipe gallery structure under train operation provided in Example 1 of the present invention;

[0035] Figure 3 A schematic diagram showing the calculation of foundation width using the analysis method provided in Example 1 of the present invention;

[0036] Figure 4 This is a schematic diagram of the overall model of the pipe gallery of Example 1 of the present invention (excluding the GIL pipe);

[0037] Figure 5 This is a schematic side elevation diagram of the pipe gallery according to Example 1 of the present invention;

[0038] Figure 6 The finite element model of the prefabricated pipe gallery structure of Example 1 of the present invention;

[0039] Figure 7 The boundary conditions of the overall model of Example 1 of the present invention;

[0040] Figure 8 The boundary conditions of the GIL pipeline in Example 1 of the present invention;

[0041] Figure 9 The train-ballasted track-bridge dynamic coupling finite element model of embodiment 1 of the present invention;

[0042] Figure 10 The train-ballasted track-bridge dynamic coupling finite element model considering train operation according to embodiment 1 of the present invention;

[0043] Figure 11 This is a diagram of the overall model deformation of the train-ballasted track-bridge dynamic coupling finite element model according to Example 1 of the present invention;

[0044] Figure 12 This is a deformation diagram of the pipe gallery joint considering train operation in Example 1 of the present invention;

[0045] Figure 13 This is a stress and displacement diagram of the pipe gallery structure considering train operation according to Example 1 of the present invention;

[0046] Figure 14 Horizontal displacement-time curves of points at the mid-span and expansion joint of the cast-in-place pipe section of Example 1 of the present invention;

[0047] Figure 15 This is the vertical displacement-time curve of each corner point at the mid-span and expansion joint of Example 1 of the present invention. DETAILED DESCRIPTION

[0048] In order to enable those skilled in the art to better understand the technical solution of the present invention and to be able to implement it, the present invention is described in detail below with reference to the accompanying drawings and specific embodiments. The following embodiments are only used to more clearly illustrate the technical solution of the present invention and are not intended to limit the scope of protection of the present invention.

[0049] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the technical solutions of the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0050] In addition, the terms "first", "second", etc. are used for descriptive purposes only and are not to be understood as indicating or implying relative importance. In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meaning of the above terms in the present invention can be understood according to the specific circumstances. In the description of the present invention, unless otherwise specified, "plurality" means two or more, which will not be described in detail here.

[0051] The present invention provides a method for analyzing the dynamic response of a prefabricated pipe gallery structure under train operation, specifically Figure 1 As shown, the following steps are included:

[0052] S1. Set contact units between the pipe sections of the prefabricated pipe gallery and determine the calculation domain and material parameters of the prefabricated pipe gallery.

[0053] S2. Based on the calculation domain and material parameters, establish the prefabricated pipe gallery structure finite element model, soft soil foundation finite element model and pipeline finite element model.

[0054] S3. Generate a prefabricated pipe gallery coupled finite element model under the soft soil foundation based on the prefabricated pipe gallery structure finite element model, the soft soil foundation finite element model, and the pipeline finite element model, and establish a pier foundation model at the corresponding position in the prefabricated pipe gallery coupled finite element model.

[0055] S4. Define the boundary conditions of the coupled finite element model of the prefabricated pipeline corridor under soft soil foundation.

[0056] S5. Perform static analysis and modal analysis of the prefabricated pipe gallery based on boundary conditions.

[0057] S6. Establish a train-ballasted track-bridge dynamic coupling finite element model, and extract the time-history response signals of the X-direction and Y-direction support reaction forces at the bottom of the bridge pier when the train is running based on the model.

[0058] S7. Based on the static and modal analysis of the prefabricated pipeline corridor, the support reaction time-history response signal is input into the pier foundation model to conduct a dynamic response analysis of the prefabricated pipeline corridor structure under soft soil foundation. The dynamic response results of the prefabricated pipeline corridor structure under train operation are obtained, and based on this, a vibration damage analysis of the cross-line railway pipeline corridor structure under train load is conducted.

[0059] Specifically, the material parameters include elastic modulus, Poisson's ratio, and density; the boundary conditions are: applying full Y-direction constraints to the bottom of the entire model, applying X-direction constraints in the horizontal direction, and applying Z-direction constraints in the vertical direction.

[0060] The calculation domain in this invention refers to the foundation depth of the calculation model. When there is no adjacent load influence and the foundation width is 1-30 m, the foundation depth of the model at the midpoint of the foundation is calculated according to formula (1):

[0061] (1)

[0062] Where: b is the width of the foundation, m.

[0063] Determine the value of the calculation width (the influence range of the calculation domain cross section) and simplify the finite element model based on the typical section in the project.

[0064] The present invention establishes a prefabricated pipe gallery structure finite element model of the pipe gallery, GIL structure, GIL support, and raft-CFG pile composite foundation through finite element software ANSYS and APDL parameterized language.

[0065] Specifically, static analysis and modal analysis of the prefabricated pipeline corridor under soft soil foundation were carried out by coupling the finite element model of the prefabricated pipeline corridor, and the first 30 modal frequencies of the prefabricated pipeline corridor structure were obtained.

[0066] In S7, a pier foundation model is established at the corresponding position in the overall finite element model of the corridor structure, and the reaction time history signal is applied to the top of the two pier foundations at the same time to perform a dynamic response analysis of the overall corridor structure.

[0067] Example 1

[0068] This embodiment uses the method provided by the present invention to verify the vibration characteristics of the tunnel structure under the action of train loads.

[0069] Taking an actual cross-line pipeline corridor tunnel project as an example, a refined finite element model of the GIL pipeline corridor tunnel structure in silt and silt soil environments was established. The X-direction and Y-direction support reaction time-history response signals of the bridge pier bottom during train operation were extracted from the train-ballasted track-bridge dynamic coupling finite element model. An overall finite element model of the pipeline corridor structure with pier foundations was established, and the reaction time-history signals were simultaneously applied to the tops of the two pier foundations to conduct a dynamic response analysis of the overall pipeline corridor structure. Figure 2 As shown, the specific steps include:

[0070] Step 1: Determine the calculation domain and parameter values ​​of the finite element model of the prefabricated pipe gallery structure.

[0071] (1) Calculation of foundation depth. According to Article 2.3.8 of the Code for Design of Building Foundations (GB 50007-2011), when there is no adjacent load influence and the foundation width is 1-30 m, the foundation deformation calculation depth at the midpoint of the foundation can be calculated using a simplified formula.

[0072]

[0073] Where: b is the width of the foundation (m), the present invention z n Take 25 m.

[0074] (2) Calculation width (influence range of calculation domain cross section) value. The calculation width of the finite element model is the influence range of the calculation domain cross section. The value is generally calculated using the following method: Figure 3 Where: B is the width of the foundation (m); f Height of clay layer (m): in this invention, the width of each side of bored pile is 30 m.

[0075] (3) Model simplification, that is, simplification of the actual project. The simplified model is 40.22 m long along the length of the tunnel. For the convenience of calculation and comparative analysis, the length of all model pipelines is 40.22 m. According to the principle of equal moment of inertia in material mechanics, the bored piles are equivalently replaced by rectangular reinforced concrete slabs with a width of 0.790 m and a height of 22.95 m. Combined with the maintenance section of the power tunnel foundation pit, the bored piles are connected to the top and bottom plates of the tunnel through plain concrete strips. For safety reasons, the 850 mm diameter cement-soil mixing pile water-stop curtains on both sides of the bored piles are not considered in the model. The total height of the concrete cushion layer at the bottom of the tunnel and the full-floor reinforced foundation is 15.2 m, and the bottom of the foundation is located on the top surface of the strongly weathered rock. The thickness of the strongly weathered rock is 9.8 m. The width of the soil on both sides of the bored piles is 30 m, and the different soil layers outside the piles are layered according to the thickness of the maintenance section of the foundation pit according to different material properties. The simplified model of the pipe corridor includes 18 prefabricated pipe sections and 1 cast-in-place pipe section. The cast-in-place pipe section including the expansion joint is 4.11m long, the prefabricated pipe section is 2.00m long, and the joint width between the expansion joint and the prefabricated pipe section is 0.03m. The cast-in-place pipe section and the two prefabricated pipe sections are located on both sides of the middle span of the entire model, which is the most unfavorable arrangement. The GIL pipe has a total of 6 supports, and the pipeline span includes the commonly used span and the maximum span in the project. The stress performance analysis is carried out while ensuring that the pipeline length direction is not affected by the calculation domain. The schematic diagram of the overall model of the pipe corridor and the schematic diagram of the side elevation of the pipe corridor are shown as follows: Figure 4 、 Figure 5 shown.

[0076] Step 2: Construct the finite element model of the prefabricated pipe gallery structure. Based on the data obtained from literature, materials and engineering construction drawings, the numerical model of the pipe gallery, GIL structure, GIL support, and raft-CFG pile composite foundation is established through the finite element software ANSYS and APDL parametric language. The silt formation, pipe gallery and raft-CFG pile composite foundation are simulated using Solid 186 units (high-order 3D 20-node solid structural units that support plasticity, hyperelasticity, creep, stress strengthening, large deformation and large strain capacity); Beam 188 beam units are used to simulate the GIL support and GIL pipeline; contact units are used for the joints between each pipe joint. In order to facilitate modeling and force analysis, the model grid is divided into hexahedral units. On the basis of meeting and complying with the actual engineering requirements, the calculation accuracy and calculation amount are considered, and the model is adjusted to make the calculation results converge. The overall finite element model of the prefabricated pipe gallery structure is as follows: Figure 6 As shown in the figure, (a) is the overall solid model, (b) is the mesh division of the overall solid model, (c) is the model of a single corridor, (d) is the mesh division of a single corridor, (e) is the overall model of the corridor, (f) is the overall mesh division of the corridor, (g) is the contact unit between corridors, (h) is the mesh division of the corridor and GIL pipe, (i) is the mesh division of the GIL pipe and bracket, and (j) is the mesh division of the GIL pipe bracket.

[0077] Step three: Determine the specific material parameters for the finite element model of the prefabricated pipe gallery structure. C40 was selected for the pipe gallery. C40 has rapid coagulation and hardening, high early strength, high hydration heat, and good frost resistance. GIL pipes offer high transmission capacity, low loss, high safety, and environmental friendliness. GIL's appearance and application environment are more similar to oil and gas pipelines. However, GIL's coaxial cylindrical structure, consisting of an inner conductor, support insulators, and outer casing, gives it a unique vibration response. Specific material parameters are shown in Table 1.

[0078] Table 1 Finite element model material parameters

[0079]

[0080] Step 4: Determine the boundary conditions of the finite element model of the prefabricated pipe gallery structure. Apply full Y-axis constraints to the bottom of the overall model, apply X-axis constraints to the horizontal direction, and apply Z-axis constraints to the vertical direction. Taking full load as an example, the overall model constraints are as follows: Figure 7 As shown in the figure, the GIL pipe cantilever bracket is fully constrained at the node where it is connected to the pipe gallery wall as a fixed support. In the cast-in-place pipe gallery section, the GIL pipe support is allowed to move vertically (in the Y direction). In the other prefabricated pipe sections, the GIL pipe support is allowed to move in one direction in addition to vertical deformation, that is, the GIL pipe can deform in the longitudinal direction (in the Z direction). The GIL pipe constraint is as follows: Figure 8 shown.

[0081] Step 5: Extract the signal of the train-ballasted track-bridge dynamic coupling finite element model. Establish the train-ballasted track-bridge dynamic coupling finite element model (such as Figure 9 As shown in Figure 3, the time-history response signals of the X-direction and Y-direction support reaction forces at the bottom of the pier are extracted when the train is running.

[0082] Step 6: Static and modal analysis: Perform static and modal analysis of the prefabricated pipe gallery based on the boundary conditions.

[0083] Step 7: Dynamic response analysis. Establish a pier foundation model (such as Figure 10 As shown in Figure 1, (a) is the finite element meshing diagram, and (b) is the finite element meshing diagram (partial). The bottom of the pier foundation falls to the top of the strongly weathered rock layer. The reaction force time history signal is applied to the top of the two pier foundations at the same time to analyze the dynamic response of the overall structure of the pipeline corridor, as shown in Figure 1. Figure 11-Figure 15 shown.

[0084] in, Figure 11Figures 1 and 2 show the deformation of the overall model, with (a) showing the X-direction displacement of the overall structure, and (b) showing the Y-direction displacement of the overall structure. As can be seen, the surrounding soil deforms primarily in the Y-direction, with a maximum value of 3.34 mm observed due to boundary conditions on both sides. Settlement has occurred at the pier foundations, with a maximum value of 3.43 mm. Slight deformation has occurred in the X-direction, concentrated at the piers.

[0085] Figure 12 In the tunnel joint deformation diagrams for train operation, (a) shows the X-axis displacement of the tunnel joint, and (b) shows the Y-axis displacement of the tunnel joint. The diagrams show that the horizontal and vertical deformation trends at the joints are generally consistent with those of the corresponding tunnel segments. The tops of the walls on both sides of the corresponding tunnel segments experience significant horizontal displacement in both positive and negative directions, and the tunnel exhibits slight distortion. The tunnel floor, especially the cantilever floor, has experienced settlement, and the intermediate corridor walls at the cast-in-place tunnel segments and boundary tunnel segments have shown an upward arching trend.

[0086] Figure 13 In order to consider the stress and displacement diagram of the tunnel structure when the train is running, Figure 13 (a) is the principal stress diagram (I) of the tunnel corridor structure, (b) is the principal stress diagram (II) of the tunnel corridor structure, (c) is the X-direction stress diagram of the tunnel corridor structure, (d) is the Y-direction stress diagram of the tunnel corridor structure, (e) is the X-direction displacement diagram of the tunnel corridor structure, and (f) is the Y-direction displacement diagram of the tunnel corridor structure. As can be seen from the figures, tensile stresses occur at the corners of the roof and outer corridor walls, the corners between the outer corridor walls and the bottom slab, and the connection between the GIL pipe supports and the tunnel corridor. Stress concentration is most significant at the corners between the cast-in-place pipe sections and the tunnel corridor bottom slabs at both ends. The middle corridor wall, outer walls, and bottom slab are primarily compressive, with maximum tensile and compressive stresses not exceeding the standard tensile and compressive strength values ​​for C40 concrete. The tunnel corridor undergoes slight deformation in both the X and Y directions, with horizontal X-direction displacement concentrated at the corners of the tunnel corridor roof. The most significant changes occur at the corners of the precast tunnel corridors at the ends, with the maximum relative deformation on both sides being 0.009 mm. The primary deformation in the Y direction was settlement, with the maximum settlement occurring at the cantilevered floor. A slight upward arching trend was observed in the middle of the cast-in-place pipe segment top slab, the intermediate gallery wall, and the corresponding floor slab. The corridor structure shifted vertically by approximately 0.012 mm. Deformation in both the X and Y directions was within the design allowable range.

[0087] Figure 14 These are the horizontal displacement-time curves of the mid-span and expansion joint points of the cast-in-place pipe section, where (a) is the horizontal displacement-time curve of the mid-span A of the cast-in-place pipe section and point A' at the expansion joint, (b) is the horizontal displacement-time curve of the mid-span B of the cast-in-place pipe section and point B' at the expansion joint, (c) is the horizontal displacement-time curve of the mid-span C of the cast-in-place pipe section and point C' at the expansion joint, and (d) is the horizontal displacement-time curve of the mid-span D of the cast-in-place pipe section and point D' at the expansion joint.

[0088] Figure 15The vertical displacement-time curves of the corner points at the mid-span and expansion joints are shown in Figure 2. Among them, (a) is the vertical displacement-time curve of the mid-span A of the cast-in-place pipe section and the point A' at the expansion joint, (b) is the vertical displacement-time curve of the mid-span B of the cast-in-place pipe section and the point B' at the expansion joint, (c) is the vertical displacement-time curve of the mid-span C of the cast-in-place pipe section and the point C' at the expansion joint, and (d) is the vertical displacement-time curve of the mid-span D of the cast-in-place pipe section and the point D' at the expansion joint. Figure 14 and Figure 15 Comparing the X- and Y-axis displacement time histories of various nodes at the tunnel corners under train operation reveals that the horizontal displacement changes at the nodes at the midspan of the cast-in-place tunnel sections and the expansion joints are essentially the same, with slight differences at the apex and bottom nodes of the outer wall, with the most significant change at the expansion joints. The vertical displacement at the four corners of the expansion joints is significantly greater than that at the midspan of the cast-in-place tunnel sections. This indicates that train operation significantly influences deformation at the expansion joints, with both horizontal and vertical displacements exceeding those at the cast-in-place tunnel sections.

[0089] This embodiment establishes a detailed finite element model of a soft soil foundation, a prefabricated pipe gallery, and pipelines, analyzes the static and dynamic responses of the prefabricated pipe gallery under real-time train operation, and analyzes the differences in dynamic responses between pipe segments through the contact setting between the pipe galleries.

[0090] The above-described embodiments are only preferred specific implementation methods of the present invention, and the protection scope of the present invention is not limited thereto. Any simple changes or equivalent replacements of the technical solutions that can be obviously obtained by any technician familiar with the field within the technical scope disclosed in the present invention fall within the protection scope of the present invention.

Claims

1. A method for analyzing the dynamic response of a prefabricated pipe gallery structure under train operation, characterized in that: The following steps are involved: Constructing a coupled finite element model of a prefabricated pipe gallery under a soft soil foundation, and establishing a pier foundation model at a corresponding position in the coupled finite element model of the prefabricated pipe gallery; Defining boundary conditions of the prefabricated pipe gallery coupled finite element model; Performing static analysis and modal analysis of the prefabricated pipe gallery based on the boundary conditions; A train-ballasted track-bridge dynamic coupling finite element model was established, and the time-history response signals of the X- and Y-direction support reactions at the bottom of the bridge piers during train operation were extracted based on this model. Based on the static and modal analysis of the prefabricated pipe gallery, the support reaction time-history response signal is input into the pier foundation model to conduct a dynamic response analysis of the prefabricated pipe gallery structure under soft soil foundation, and the dynamic response results of the prefabricated pipe gallery structure under train operation are obtained.

2. The method for analyzing the dynamic response of a prefabricated pipe gallery structure under train operation according to claim 1 is characterized in that: The construction of the coupled finite element model of the prefabricated pipe gallery under the soft soil foundation specifically includes: Set contact units between pipe segments of the prefabricated pipe gallery and determine the calculation domain and material parameters of the prefabricated pipe gallery; Establishing a prefabricated pipe gallery structure finite element model, a soft soil foundation finite element model, and a pipeline finite element model based on the calculation domain and material parameters; A coupled finite element model of the prefabricated pipe gallery under the soft soil foundation is generated according to the finite element model of the prefabricated pipe gallery structure, the finite element model of the soft soil foundation and the finite element model of the pipeline.

3. The method for analyzing the dynamic response of a prefabricated pipe gallery structure under train operation according to claim 2 is characterized in that: The establishment of the prefabricated pipe gallery structure finite element model, the soft soil foundation finite element model and the pipeline finite element model specifically includes: Utilizing existing support structure design methods, the 3D structure of the prefabricated pipe gallery, soft soil foundation, and pipelines was established using ANSYS finite element analysis software. Based on the three-dimensional structure and combined with parametric language, the finite element model of the prefabricated pipeline corridor structure, the finite element model of the soft soil foundation and the finite element model of the pipeline are established.

4. The method for analyzing the dynamic response of a prefabricated pipe gallery structure under train operation according to claim 3 is characterized in that: The finite element model of the prefabricated pipe gallery structure includes a pipe gallery, a GIL bracket, a GIL pipeline, and a raft-CFG pile composite foundation.

5. The method for analyzing the dynamic response of a prefabricated pipe gallery structure under train operation according to claim 3 is characterized in that: Defining the calculation domain, material parameters and boundary conditions in ANSYS finite element analysis software; The material parameters include elastic modulus, Poisson's ratio, and density; The boundary conditions are: applying full Y-direction constraint to the bottom of the whole model, applying X-direction constraint to the horizontal direction, and applying Z-direction constraint to the vertical direction; The calculation domain refers to the foundation depth of the calculation model. When there is no adjacent load influence and the foundation width is 1-30m, the foundation depth of the model at the midpoint of the foundation is calculated according to formula (1): With n =b(2.5-0.4lnb) (1) Where: b is the width of the foundation, m.

6. The method for analyzing the dynamic response of a prefabricated pipe gallery structure under train operation according to claim 4 is characterized in that: In the finite element model of the prefabricated pipe gallery structure, the soft soil layer, pipe gallery, and raft-CFG pile composite foundation are all simulated using Solid 186 elements; Beam 188 beam elements are used to simulate the GIL bracket and GIL pipeline; contact elements are used for the joints between each pipe joint, and the model mesh is divided into hexahedral elements.

7. The method for analyzing the dynamic response of a prefabricated pipe gallery structure under train operation according to claim 1 is characterized in that: The static analysis and modal analysis of the prefabricated pipe gallery are performed based on the boundary conditions to obtain the first 30 modal frequencies of the prefabricated pipe gallery structure.

8. The method for analyzing the dynamic response of a prefabricated pipe gallery structure under train operation according to claim 1 is characterized in that: There are two pier foundation models, and the process of inputting the support reaction time-history response signal into the pier foundation model to perform a dynamic response analysis of the prefabricated pipeline corridor structure under a soft soil foundation is specifically as follows: the reaction time-history signal is simultaneously applied to the foundation tops of the two pier foundation models to perform a dynamic response analysis of the overall pipeline corridor structure.

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