A method and apparatus for testing the wear of large-diameter slag in a shield tunnel grout discharge pipeline.

Abstract

The present invention discloses a method and apparatus for testing the wear of large-particle slag in shield tunneling slurry pipes. The method relates to the field of tunnel engineering technology. The method comprises the following steps: using a weighing instrument to measure the initial weight of a cleaned test target; setting the slurry flow rate in the shield tunneling slurry pipe according to the layout of the shield tunneling slurry pipe, determining wear test parameters, and designing a wear test based on the wear test parameters; adjusting the height of the slag drop pipe using a pipe support, and adjusting the inclination angle of the target fixture using a box-type support; dropping slag particles into the slag drop pipe using a feeding funnel, and calculating the wear rate of the test target; plotting a curve showing the change of different wear test parameters against the test target wear rate, and fitting the curve using a particle size function and an impact angle function to obtain a test target wear model; and correcting the test target wear model using a model correction coefficient. The present invention improves the accuracy of wear prediction for shield tunneling slurry pipes.

Description

Technical Field

[0001] This invention relates to the field of tunnel engineering technology, and more specifically, to a method and apparatus for testing the wear of large-diameter slag in shield tunnel grouting pipelines. Background Technology

[0002] With the continuous development of the economy and the constant improvement of technology, the demand for infrastructure construction is increasing, and tunnel and underground engineering have ushered in unprecedented development opportunities. Various complex geological conditions and construction environments have placed higher demands on shield tunneling technology. Due to its advantages such as safety, efficiency, and environmental friendliness, shield tunneling has become one of the main methods for tunnel and underground engineering construction. Especially under complex geological conditions such as soft soil strata and water-rich strata, slurry balance shield tunneling has been widely used due to its excellent adaptability and stability.

[0003] The slurry circulation system is a core component of slurry-balanced shield tunneling machines, mainly consisting of slurry discharge pipelines and slurry treatment equipment. During shield tunneling, the slurry circulation system discharges slurry carrying excavated rock through pipelines. The rock particles carried in the slurry inevitably cause wear on the pipelines, especially at bends. Long-term wear accumulation can lead to pipeline rupture, slurry leakage, and other safety hazards, even forcing the shield machine to be shut down for maintenance, thus increasing project time and economic costs. To address this issue, scholars both domestically and internationally have conducted extensive research on the pipeline wear mechanism of solid-liquid two-phase flow and proposed various wear models.

[0004] However, existing traditional wear models still have some limitations when applied to the wear problem of large-diameter slag in shield tunnel slurry discharge pipelines. First, the wear problem in solid-liquid two-phase flow pipelines is very complex. Traditional wear models are mostly designed for the erosion of micron-sized particles, while the slag particles in shield slurry discharge are usually on the centimeter scale. The wear mechanisms of the two are significantly different, making it difficult for traditional wear models to accurately describe the wear law of large-diameter slag. Second, traditional wear models often ignore the variation range of slurry flow velocity in the slurry shield circulation system and do not fully consider the influence of particle shape on wear. This results in deviations between experimental data and actual engineering conditions, making it difficult to reflect the wear characteristics of slag with different shapes in on-site slag discharge.

[0005] These issues result in low accuracy of traditional wear models when applied to slurry discharge pipelines in slurry shield tunnels, making it difficult to meet the needs of engineering practice. Therefore, it is urgent to conduct a systematic investigation into the impact wear of large-diameter slag in slurry discharge pipelines of slurry shield tunnels and to propose a suitable high-precision wear model to improve the accuracy and reliability of wear prediction.

[0006] There are currently no effective solutions to the problems in the relevant technologies. Summary of the Invention

[0007] To address the problems in related technologies, this invention proposes a method and apparatus for testing the wear of large-diameter slag in shield tunnel grouting pipelines. This method has the advantages of establishing a wear model with strong engineering applicability, improving the wear prediction accuracy of shield tunnel grouting pipelines, reducing the risk of pipeline damage and slurry leakage, reducing the number of shield machine downtimes for maintenance, and saving time and costs. Furthermore, it solves the problem that existing traditional wear models are mostly designed for micron-sized particle erosion conditions, which have limitations when used to study the wear of large-diameter slag, resulting in low wear prediction accuracy.

[0008] Therefore, the specific technical solution adopted by the present invention is as follows:

[0009] According to one aspect of the present invention, a method for testing the wear of large-diameter slag in a shield tunnel grout discharge pipeline is provided, the method comprising the following steps:

[0010] S1. Select the geometric dimensions and steel type of the test target, clean the surface of the test target using a grinding tool, and weigh the initial weight of the cleaned test target using a weighing instrument.

[0011] S2. Based on the arrangement of the shield tunnel grouting pipeline, set the slurry flow rate of the shield tunnel grouting pipeline and determine the wear test parameters. Design the wear test based on the wear test parameters.

[0012] S3. Use the pipe support to adjust the height of the slag falling into the pipe, and use the box-type support to adjust the tilt angle of the target clamp. Place the cleaned test target in the center of the target clamp and fix it.

[0013] S4. Weigh and record the weight of the slag particles before the wear test. Put the slag particles into the slag drop pipe through the feeding funnel, carry out the wear test, and record the weight of the slag particles after the wear test. Calculate the wear rate of the test target material and obtain the wear test results.

[0014] S5. By adjusting the wear test parameters, repeat steps S1-S4. Based on the wear test results, plot the change curves of impact velocity, impact angle, particle size, particle shape and wear rate of the test target, and establish the particle size function and impact angle function based on the change curves. Use the particle size function and impact angle function to fit the change curves to obtain the wear model of the test target.

[0015] S6. Based on the integrated development environment, compile the dynamic link library file of the test target wear model, establish the simulated working conditions through discrete element simulation software, and use the model correction coefficient to correct the test target wear model.

[0016] Furthermore, based on the arrangement of the shield tunnel grout discharge pipeline, the grout flow rate of the shield tunnel grout discharge pipeline is set, and the wear test parameters are determined. The wear test is designed based on the wear test parameters, including the following steps:

[0017] S21. Based on the arrangement of the shield tunnel grouting pipeline, with the goal of preventing grouting blockage in the shield tunnel grouting pipeline, the grout flow rate of the shield tunnel grouting pipeline is set.

[0018] S22. Determine the wear test parameters based on the slurry flow rate of the shield tunnel's slurry discharge pipeline. The wear test parameters include impact velocity, impact angle, particle size, and particle shape.

[0019] S23. Based on the wear test parameters, design wear tests with different impact velocities, impact angles, particle sizes and particle shapes, and set multiple test angles.

[0020] Furthermore, the initial weight of the slag particles before the wear test was weighed and recorded. The slag particles were then fed into the slag drop pipe through a feeding funnel for the wear test. The remaining weight of the slag particles after the wear test was recorded, and the wear rate of the test target was calculated. The wear test results include:

[0021] S41. Weigh and record the initial weight of the slag particles before the wear test. Place the slag particles into the feeding funnel. After the preset test time is reached, remove the test target from the target fixture.

[0022] S42. Weigh the remaining weight of the test target using a weighing instrument, and calculate the wear mass of the test target in combination with the initial weight of the test target.

[0023] S43. When the wear mass of the test target material reaches the wear threshold, weigh the remaining mass of the slag particles, record the total used mass of the slag particles, and calculate the wear rate of the test target material.

[0024] Furthermore, the wear thresholds include the wear threshold for spherical particles, the wear threshold for triangular prism particles, and the wear threshold for flat particles;

[0025] The wear mass of the test target is the difference between the initial weight of the test target and the remaining weight of the test target;

[0026] The total usable mass of slag and stone particles is the difference between the initial weight of the slag and stone particles and the remaining mass of the slag and stone particles.

[0027] The wear rate of the test target is the ratio of the wear mass of the test target to the total used mass of the slag particles.

[0028] Furthermore, by adjusting the wear test parameters and repeating steps S1-S4, and based on the wear test results, plot the variation curves of impact velocity, impact angle, particle size, particle shape, and wear rate of the test target, respectively. Then, establish a particle size function and an impact angle function based on these curves. By fitting the variation curves using the particle size function and impact angle function, the wear model of the test target is obtained, including the following steps:

[0029] S51. By adjusting different impact speeds, impact angles, particle sizes and particle shapes, repeat steps S1-S4 to obtain several wear test results.

[0030] S52. Based on the wear test results, plot the curves showing the changes in impact velocity, impact angle, particle size, particle shape, and wear rate of the test target.

[0031] S53. Based on the variation curve, determine the functional form of the wear model of the test target, including the particle size function, impact angle function, velocity exponent and shape factor;

[0032] S54. Based on the wear rate variation curve of the test target and the functional form of the wear model of the test target, establish the wear model of the test target using mathematical modeling tools.

[0033] Furthermore, the expression for the particle size function is:

[0034] f(d p )=A·d p +B

[0035] In the formula, f(d) p ) represents the particle size function, A represents the first constant, and d p represents the particle size of the slag stone, and B represents the second constant;

[0036] The expression for the impact angle function is:

[0037]

[0038] In the formula, f(θ) represents the impact angle function, θ represents the magnitude of the impact angle, and D i This represents the third constant during the i-th fitting;

[0039] The expression for the wear model of the test target is:

[0040] R = C·f(d) p f(θ)v b(v)

[0041] In the formula, R represents the erosion wear rate, C represents the shape coefficient, v represents the particle velocity of the slag, and b(v) represents the velocity index.

[0042] Furthermore, based on the integrated development environment, the dynamic link library file of the test target wear model is compiled, and the simulated working conditions are established using discrete element simulation software. The test target wear model is then corrected using model correction coefficients, including the following steps:

[0043] S61. Based on the integrated development environment, create a new project file and compile the header and source files of the test target wear model, and copy them to the directory of the new project file;

[0044] S62. Add code files to the new project file and compile them to generate a dynamic link library file for the test target wear model;

[0045] S63. Use discrete element simulation software to set the contact model parameters between particles and geometry, load the dynamic link library file of the test target wear model, establish the simulated working condition, and use the model correction coefficient to correct the test target wear model. The model correction coefficient is the ratio of the actual thickness loss of the pipeline to the numerically calculated thickness loss.

[0046] According to another aspect of the present invention, a test device for large-diameter slag abrasion in a shield tunnel slurry discharge pipeline is also provided, the test device comprising a feeding funnel;

[0047] The bottom of the feeding hopper is equipped with a slag and stone falling pipe. A pipe support is installed on the outside of the slag and stone falling pipe. Several pipe clamps that cooperate with the slag and stone falling pipe are installed in the middle of the pipe support. A box-shaped support is installed at the bottom of the pipe support. A target clamp is installed on the inside of the box-shaped support. The bottom of the slag and stone falling pipe is aligned with the center of the target clamp. A slag and stone collection box is installed at the bottom of the box-shaped support.

[0048] Furthermore, the slag and stone drop pipe is used in conjunction with the feeding funnel to feed slag and stone particles;

[0049] Pipe supports are used to fix the slag and stone falling pipes, and the height of the slag and stone falling pipes is changed by pipe clamps to adjust the speed of the slag and stone particles impacting the test target.

[0050] Target clamps are used to fix test targets;

[0051] The slag collection box is used to collect slag particles after the wear test;

[0052] The box-type support is used to adjust the tilt angle of the target clamp, so as to achieve adjustment of the multi-level test angle.

[0053] Furthermore, the top of the target clamp is provided with several target limiting bolts, and several limiting holes are symmetrically opened on both sides of the box bracket. Screws are provided through the limiting holes on both sides of the target clamp.

[0054] Among them, the target limiting bolts are used to fix the position of the test target;

[0055] The screw is used to adjust and fix the tilt angle of the target clamp by engaging with the limiting hole.

[0056] The beneficial effects of the present invention are:

[0057] (1) By using a test device for impact abrasion of large-diameter slag targets in the laboratory, this invention establishes an engineering-applicable wear model, which overcomes the problem of poor applicability of existing wear models to the wear prediction of slurry drainage pipes of slurry shield tunnels, and improves the applicability and calculation accuracy of the model. Compared with the test background of "high speed and small particle size" of existing wear models, the wear model established by this invention has the characteristics of "low speed and large particle size" in its applicable range. It can more accurately predict the wear problem of slurry drainage pipes in actual engineering, and repair or replace severely worn parts in time before the pipes fail. This helps to solve the problem of slurry shield tunneling shutdown and maintenance caused by slurry pipe damage and slurry leakage, and saves time and costs.

[0058] (2) Based on existing wear models, a wear model for large-diameter slag was proposed, revealing the wear law of large-diameter slag, which is more consistent with actual engineering.

[0059] (3) By setting the impact velocity of slag in the wear test according to the range of slurry flow velocity variation for the slurry shield circulation system, the accuracy of the test data was improved.

[0060] (4) By exploring the influence of particle shape on wear, spherical particles were used as the standard test, and flat slag with edges and triangular prism slag were selected as test particles according to the distribution of slag shape in the field, so that the research results are more comprehensive.

[0061] (5) By adopting numerical simulation methods and combining field measurement data, the model was corrected, which further improved the calculation accuracy of the wear model. Attached Figure Description

[0062] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0063] Figure 1 This is a schematic flowchart of a method for testing the wear of large-diameter slag in a shield tunnel grout discharge pipeline according to an embodiment of the present invention.

[0064] Figure 2 This is a front view of a shield tunnel slurry discharge pipeline large-diameter slag abrasion test device according to an embodiment of the present invention;

[0065] Figure 3 This is a left view of a test device for large-diameter slag abrasion in a shield tunnel slurry discharge pipeline according to an embodiment of the present invention;

[0066] Figure 4 This is a left view of a box-type support in a shield tunnel slurry discharge pipeline large-diameter slag abrasion test device according to an embodiment of the present invention;

[0067] Figure 5 This is a top view of a box-type support in a shield tunnel slurry discharge pipeline large-diameter slag abrasion test device according to an embodiment of the present invention;

[0068] Figure 6 This is a schematic diagram of the change curves of impact velocity and wear rate of test target material in a shield tunnel slurry discharge pipeline large-particle slag wear test method according to an embodiment of the present invention;

[0069] Figure 7 This is a schematic diagram of the change curve of impact angle and wear rate of test target material in a shield tunnel slurry discharge pipeline large-particle slag wear test method according to an embodiment of the present invention;

[0070] Figure 8 This is a schematic diagram of the variation curves of particle size and wear rate of the test target material in a large-particle slag wear test method for a shield tunnel slurry discharge pipeline according to an embodiment of the present invention.

[0071] In the picture:

[0072] a. Feeding funnel; b. Slag and stone dropping pipe; c. Pipe support; d. Pipe clamp; e. Slag and stone collection box; f. Box-type support; g. Limiting hole; h. Screw; i. Target material limiting bolt. Detailed Implementation

[0073] To further illustrate the various embodiments, the present invention provides accompanying drawings, which are part of the disclosure of the present invention. These drawings are mainly used to illustrate the embodiments and can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. With reference to these drawings, those skilled in the art should be able to understand other possible implementation methods and the advantages of the present invention. The components in the drawings are not drawn to scale, and similar component symbols are generally used to represent similar components.

[0074] According to an embodiment of the present invention, a method and apparatus for testing the wear of large-diameter slag in a shield tunnel grout discharge pipeline are provided.

[0075] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments, such as... Figure 1 As shown, according to an embodiment of the present invention, a method for testing the wear of large-diameter slag in a shield tunnel grout discharge pipeline is provided. This method includes the following steps:

[0076] S1. Select the geometric dimensions and steel type of the test target, clean the surface of the test target using a grinding tool, and weigh the initial weight of the cleaned test target using a weighing instrument.

[0077] S2. Based on the arrangement of the shield tunnel grouting pipeline, set the slurry flow rate of the shield tunnel grouting pipeline and determine the wear test parameters. Design the wear test based on the wear test parameters.

[0078] S3. Use pipe support c to adjust the height of the slag falling through pipe b, and use box support f to adjust the tilt angle of the target clamp. Place the cleaned test target in the center of the target clamp and fix it.

[0079] S4. Weigh and record the weight of the slag particles before the wear test. Put the slag particles into the slag drop pipe through the feeding funnel, carry out the wear test, and record the weight of the slag particles after the wear test. Calculate the wear rate of the test target material and obtain the wear test results.

[0080] S5. By adjusting the wear test parameters, repeat steps S1-S4. Based on the wear test results, plot the change curves of impact velocity, impact angle, particle size, particle shape and wear rate of the test target, and establish the particle size function and impact angle function based on the change curves. Use the particle size function and impact angle function to fit the change curves to obtain the wear model of the test target.

[0081] S6. Based on the integrated development environment, compile the dynamic link library file of the test target wear model, establish the simulated working conditions through discrete element simulation software, and use the model correction coefficient to correct the test target wear model.

[0082] Specifically, this experimental method calculates the wear rate by the ratio of the loss mass of the test target material to the total mass of the slag particles. The impact velocity, impact angle, particle size, and particle shape are used as independent variables to design the experiment. The test results are then fitted and analyzed to establish a wear prediction equation and obtain a wear model.

[0083] Specifically, in the experiment, the shape of large-diameter slag particles was based on spherical particles, and other irregularly shaped slag particles were selected according to the actual working conditions. The particle size of the slag particles was based on the sampling in the project, which was used to simulate slag particles of different shapes and sizes in the actual project.

[0084] Specifically, in this embodiment, the test target material is a plate with dimensions of 200mm*200mm*3mm. The large-diameter slag particles are shaped into three types: spherical particles (without sharp edges), triangular prism particles (with sharp edges), and flat particles (with sharp edges), with particle sizes of 1cm, 2cm, and 3cm, respectively, to simulate slag particles of different shapes and sizes in actual engineering. This embodiment explores the test method for the impact wear model of large-diameter slag particles, including the following steps:

[0085] ① Weighing the target material: In this embodiment, a test target material with a size of 200mm*200mm*3mm is made. The steel type is Q235 steel and Q345 steel. The rust and stains on the surface of the test target material are cleaned with sandpaper. The weighing is recorded on a high-precision electronic scale. The surface of the test target material is cleaned before each subsequent weighing.

[0086] ② Wear Scheme: With the goal of ensuring smooth and unblocked slurry discharge in the pipe, the slurry flow rate of the slurry discharge pipe of the slurry shield tunnel is set. In this embodiment, the slurry flow rate is set to above 3m / s. The common pipe layout is a 90° bend. Wear tests are designed for different impact velocities, impact angles and particle sizes. The angle is set in four levels: 15°, 30°, 45° and 60°.

[0087] ③ Height adjustment: Adjust the position of the pipe clamp d on the pipe support c to adjust the slag and stone falling pipe b to the specified height;

[0088] ④ Angle adjustment: After tilting the target clamp on the box-type bracket f to the specified angle, use the screw h to pass through the bracket limit hole g, and use the nut to complete the fixing operation;

[0089] ⑤ Target installation: Place the cleaned target in the center of the target fixture and use the target limiting bolts to fix the target around its perimeter;

[0090] ⑥ Adding Slag: The wear rate is defined as the ratio of the mass lost by the test target to the total mass of the slag particles used. Before the test, the slag particles are weighed and recorded. The slag particles are then added from the upper feeding funnel a. After each addition, the target is removed from the target fixture and weighed on a high-precision electronic scale. After each fixed mass of wear on the target, the remaining slag particles are weighed again and the total mass of the slag particles used is recorded. The wear threshold for each fixed mass of wear on the target is set as follows: 0.2g for spherical particles, 0.3g for triangular prism particles, and 0.3g for flat particles. The test is repeated multiple times until the wear rate tends to stabilize. After that, the test parameters are adjusted and steps ①-⑥ are repeated.

[0091] ⑦ Experimental data processing: Based on the experimental results, analyze the effects of impact velocity, impact angle, particle size and particle shape on the wear rate of the target material, plot the influence curves of the four parameters, select an appropriate fitting equation form based on the curves, and finally establish a large-particle-size slag impact wear model.

[0092] ⑧ Wear Model Correction: In this embodiment, a user-defined contact model method based on the EDEM API is used. The wear model file is compiled into a DLL file using the Visual Studio tool. This DLL file is then loaded into the EDEM contact model and used for model correction and calculation.

[0093] In one embodiment, based on the arrangement of the shield tunnel grout discharge pipeline, the slurry flow rate of the shield tunnel grout discharge pipeline is set, and the wear test parameters are determined. The wear test is designed based on the wear test parameters, including the following steps:

[0094] S21. Based on the arrangement of the shield tunnel grouting pipeline, with the goal of preventing grouting blockage in the shield tunnel grouting pipeline, the grout flow rate of the shield tunnel grouting pipeline is set.

[0095] S22. Determine the wear test parameters based on the slurry flow rate of the shield tunnel's slurry discharge pipeline. The wear test parameters include impact velocity, impact angle, particle size, and particle shape.

[0096] S23. Based on the wear test parameters, design wear tests with different impact velocities, impact angles, particle sizes and particle shapes, and set multiple test angles.

[0097] Specifically, wear tests are designed for different impact velocities, impact angles, and particle sizes. In the above embodiment, the multi-level test angles are set to four levels, including 15°, 30°, 45°, and 60°.

[0098] In one embodiment, the initial weight of the slag particles before the wear test is weighed and recorded. The slag particles are then fed into the slag drop pipe through a feeding funnel for the wear test. The remaining weight of the slag particles after the wear test is recorded, and the wear rate of the test target is calculated. The wear test results include:

[0099] S41. Weigh and record the initial weight of the slag particles before the wear test. Put the slag particles into the feeding funnel a. After the preset test time is reached, remove the test target from the target fixture.

[0100] S42. Weigh the remaining weight of the test target using a weighing instrument, and calculate the wear mass of the test target in combination with the initial weight of the test target.

[0101] S43. When the wear mass of the test target material reaches the wear threshold, weigh the remaining mass of the slag particles, record the total used mass of the slag particles, and calculate the wear rate of the test target material.

[0102] In one embodiment, the wear threshold includes a spherical particle wear threshold, a triangular prism particle wear threshold, and a flat particle wear threshold.

[0103] The wear mass of the test target is the difference between the initial weight of the test target and the remaining weight of the test target;

[0104] The total usable mass of slag and stone particles is the difference between the initial weight of the slag and stone particles and the remaining mass of the slag and stone particles.

[0105] The wear rate of the test target is the ratio of the wear mass of the test target to the total used mass of the slag particles.

[0106] In one embodiment, by adjusting the wear test parameters and repeating steps S1-S4, and based on the wear test results, plotting the variation curves of impact velocity, impact angle, particle size, particle shape, and wear rate of the test target, and establishing a particle size function and an impact angle function based on the variation curves, and fitting the variation curves using the particle size function and impact angle function to obtain the wear model of the test target, the following steps are included:

[0107] S51. By adjusting different impact speeds, impact angles, particle sizes and particle shapes, repeat steps S1-S4 to obtain several wear test results.

[0108] S52. Based on the wear test results, plot the curves showing the changes in impact velocity, impact angle, particle size, particle shape, and wear rate of the test target.

[0109] S53. Based on the variation curve, determine the functional form of the wear model of the test target, including the particle size function, impact angle function, velocity exponent and shape factor;

[0110] S54. Based on the wear rate variation curve of the test target and the functional form of the wear model of the test target, establish the wear model of the test target using mathematical modeling tools.

[0111] Specifically, ⑦ experimental data processing includes the following steps:

[0112] 1) Calculate the average wear rate under each test condition using the ratio of the target material loss mass to the total mass of the slag particles. Plot the wear rate variation curves for different impact velocities, impact angles, particle sizes, and particle shapes, such as... Figure 6-Figure 8 As shown;

[0113] 2) Based on the obtained change curve image, the function form is initially determined. In this embodiment, the particle size function is set to a linear function, the impact angle function is set to a quartic function, and the velocity exponent and shape factor are constants. The equations for the particle size function and the impact angle function are as follows:

[0114] The expression for the particle size function is:

[0115] f(d p )=A·d p +B

[0116] In the formula, f(d) p ) represents the particle size function, A represents the first constant, and d p A represents the particle size of the slag and stone, B represents the second constant, and A and B are given by fitting the curve of the change between particle size and wear rate of the test target material. In this embodiment, the example values ​​are A = 8.25 and B = 35.3.

[0117] The expression for the impact angle function is:

[0118]

[0119] In the formula, f(θ) represents the impact angle function, θ represents the magnitude of the impact angle, and D i D represents the third constant during the i-th fitting (in this embodiment, i = 1, 2, 3, 4). i The curves showing the relationship between the impact angle and the wear rate of the test target are given after fitting.

[0120] A wear model is established, and the expression for the wear model of the test target is as follows:

[0121] R = C·f(d) p f(θ)v b(v)

[0122] In the formula, R represents the erosion wear rate, C represents the shape factor, v represents the particle velocity of the slag, and b(v) represents the velocity index.

[0123] 3) Using mathematical modeling tools (the fitting toolbox of MATLAB software in this embodiment), the curves are fitted according to the changing curves and the determined function form to complete the establishment of the wear model.

[0124] Specifically, in the above embodiments, the equations for establishing the wear models of Q235 and Q345 sputtering targets are as follows:

[0125] R Q235 =2.3×10 -12 C(8.25d p +35.3)·

[0126] (7.30θ-0.271θ 2 +3.54×10 -3 θ 3 -1.56×10 -5 θ 4 )v 3.06

[0127] R Q345 =5.3×10 -12 C(6.88d p +25.2)·

[0128] (6.26θ-0.244θ 2 +3.40×10 -3 θ 3 -1.61×10 -5 θ 4 )v 2.75

[0129] In the formula, R is the erosion wear rate, with units of kg / kg; d p θ is the particle size in mm; θ is the impact angle in °; v is the particle velocity in m / s; C is the shape factor, in this embodiment, the shape factors of spherical, flat, and triangular prism-shaped slag particles are C = 1, 1.4, and 1.8, respectively; 2.3 × 10⁻⁶ -12 and 5.3×10 -12 These are the fitting constants obtained by fitting the experimental data of Q235 and Q345 targets using the fitting toolbox of MATLAB software in this embodiment.

[0130] In one embodiment, the process of compiling the dynamic link library file of the test target wear model based on an integrated development environment, establishing simulated working conditions using discrete element simulation software, and correcting the test target wear model using model correction coefficients includes the following steps:

[0131] S61. Based on the integrated development environment, create a new project file and compile the header and source files of the test target wear model, and copy them to the directory of the new project file;

[0132] S62. Add code files to the new project file and compile them to generate a dynamic link library file for the test target wear model;

[0133] S63. Use discrete element simulation software to set the contact model parameters between particles and geometry, load the dynamic link library file of the test target wear model, establish the simulated working condition, and use the model correction coefficient to correct the test target wear model. The model correction coefficient is the ratio of the actual thickness loss of the pipeline to the numerically calculated thickness loss.

[0134] Specifically, step ⑧, wear model correction, includes the following steps:

[0135] 1) Create a new empty DLL project in the integrated development environment (Visual Studio in this embodiment), compile the header files and source files, and copy them to the same directory as the header files (API Core and API Contact Model files in this embodiment) of the discrete element simulation software (EDEM) API file to obtain the new project file;

[0136] 2) Add code files (in this example, cpp format files) to the new project file and compile them, write them into the test wear model, and then compile the new project file to generate a dll file;

[0137] 3) In this embodiment, a Contact Model between particles and geometry is set in EDEM, a DLL file is loaded, and simulation conditions are set. Taking the wear of a 90-degree bend in a large-diameter slag as an example, the pipe wear thickness in the calculation results is analyzed and compared with the actual wear thickness measurement value. A model correction coefficient K is introduced, which is expressed as the ratio of the actual thickness loss to the numerically calculated thickness loss. The wear model is corrected, and the equation expression of the corrected wear model is: ER=K×R, where ER represents the erosion wear rate obtained by the corrected wear model, and R represents the erosion wear rate.

[0138] Specifically, in the above embodiment, the calculated K value is 0.82. Furthermore, in the above embodiment, the final equation expression for the wear model after correction of Q235 and Q345 targets is as follows:

[0139] ER Q235 =1.89×10 -12 C(8.25d p +35.3)·

[0140] (7.30θ-0.271θ 2 +3.54×10 -3 θ 3 -1.56×10 -5 θ 4 )v 3.06

[0141] ER Q345 =4.35×10 -12 C(6.88d p +25.2)·

[0142] (6.26θ-0.244θ 2 +3.40×10 -3 θ 3 -1.61×10 -5 θ 4 )v 2.75

[0143] In the formula, ER is the erosion wear rate obtained from the modified wear model, in kg / kg; d p θ is the particle size in mm; θ is the impact angle in °; v is the particle velocity in m / s; C is the shape factor. In the above embodiments, the shape factors of spherical, flat, and triangular prism-shaped slag particles are C = 1, 1.4, and 1.8, respectively; 1.389 × 10⁻⁶. -12 and 4.35×10 -12 This is the product of the fitting constant and the model correction coefficient K obtained by fitting the experimental data of Q235 and Q345 targets using the fitting toolbox of MATLAB software in this embodiment.

[0144] like Figures 2-5 As shown, according to another embodiment of the present invention, a test device for large-diameter slag wear in a shield tunnel slurry discharge pipeline is also provided, the test device for large-diameter slag wear in a shield tunnel slurry discharge pipeline includes a feeding funnel a;

[0145] The bottom of the feeding funnel a is equipped with a slag falling pipe b. A pipe support c is installed on the outside of the slag falling pipe b. Several pipe clamps d that cooperate with the slag falling pipe b are installed in the middle of the pipe support c. A box-shaped support f is installed at the bottom of the pipe support c. A target clamp is installed on the inside of the box-shaped support f. The bottom of the slag falling pipe b is aligned with the center of the target clamp. A slag collection box e is installed at the bottom of the box-shaped support f.

[0146] In one embodiment, the slag drop pipe b is used in conjunction with the feeding funnel a to feed slag particles;

[0147] Pipe support c is used to fix the slag falling pipe b, and the height of the slag falling pipe b is changed by pipe clamp d to adjust the speed of the slag particles impacting the test target.

[0148] Target clamps are used to fix test targets;

[0149] Slag and stone collection box e is used to collect slag and stone particles after the wear test;

[0150] The box-shaped bracket f is used to adjust the tilt angle of the target clamp, thereby enabling adjustment of multiple test angles.

[0151] In one embodiment, a number of target limiting bolts i are provided through the top of the target clamp, and a number of limiting holes g are symmetrically opened on both sides of the box bracket f. A screw h is provided through the limiting holes g on both sides of the target clamp, and the angle is adjustable between 0 and 90°.

[0152] Among them, the target limiting bolt i is used to fix the position of the test target;

[0153] The screw h is used to adjust and fix the tilt angle of the target clamp in conjunction with the limiting hole g.

[0154] In summary, by employing the above-mentioned technical solution of this invention, the problem of poor applicability of existing wear models to the wear prediction of slurry drainage pipes in slurry shield tunnels is overcome, thus improving the model's applicability and calculation accuracy. By using experimental equipment for impact wear of large-diameter slag targets in the laboratory, an engineering-applicable wear model is established, improving the wear prediction accuracy of shield tunnel slurry drainage pipes. This allows for timely implementation of repair welding or pipe replacement measures, reducing the risk of shield machine downtime for maintenance due to pipe damage, slurry leakage, etc., and saving time and costs. Furthermore, this invention proposes a wear model specifically for large-diameter slag based on existing wear models. The study revealed the wear patterns of large-diameter slag, which are more consistent with actual engineering practices. By setting the slag impact velocity in the wear test based on the slurry flow velocity variation range for the slurry shield tunneling circulation system, the accuracy of the test data was improved. By exploring the influence of particle shape on wear, spherical particles were used as the standard test, and flat slag with edges and triangular prism slag were selected as test particles based on the slag shape distribution in the field, making the research results more comprehensive. By using numerical simulation methods and combining them with field measurement data, the model was corrected, further improving the calculation accuracy of the wear model.

[0155] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for testing the wear of large-diameter slag in a shield tunnel grout discharge pipeline, characterized in that, The method for testing the wear resistance of large-diameter slag in the shield tunneling grout discharge pipeline includes the following steps: S1. Select the geometric dimensions and steel type of the test target, clean the surface of the test target using a grinding tool, and weigh the initial weight of the cleaned test target using a weighing instrument. S2. Based on the arrangement of the shield tunnel grouting pipeline, set the slurry flow rate of the shield tunnel grouting pipeline and determine the wear test parameters. Design the wear test based on the wear test parameters. S3. Use the pipe support to adjust the height of the slag falling into the pipe, and use the box-type support to adjust the tilt angle of the target clamp. Place the cleaned test target in the center of the target clamp and fix it. S4. Weigh and record the weight of the slag particles before the wear test. Put the slag particles into the slag drop pipe through the feeding funnel, carry out the wear test, and record the weight of the slag particles after the wear test. Calculate the wear rate of the test target material and obtain the wear test results. S5. By adjusting the wear test parameters, repeat steps S1-S4. Based on the wear test results, plot the change curves of impact velocity, impact angle, particle size, particle shape and wear rate of the test target, and establish the particle size function and impact angle function based on the change curves. Use the particle size function and impact angle function to fit the change curves to obtain the wear model of the test target. S6. Based on the integrated development environment, compile the dynamic link library file of the test target wear model, establish the simulated working conditions through discrete element simulation software, and use the model correction coefficient to correct the test target wear model.

2. The method for testing the wear of large-diameter slag in a shield tunnel grout discharge pipeline according to claim 1, characterized in that, The steps for setting the slurry flow rate in the shield tunneling slurry discharge pipeline according to its layout and determining the wear test parameters, and designing the wear test based on these parameters, include the following: S21. Based on the arrangement of the shield tunnel grouting pipeline, with the goal of preventing grouting blockage in the shield tunnel grouting pipeline, the grout flow rate of the shield tunnel grouting pipeline is set. S22. Determine the wear test parameters based on the slurry flow rate of the shield tunnel's slurry discharge pipeline. The wear test parameters include impact velocity, impact angle, particle size, and particle shape. S23. Based on the wear test parameters, design wear tests with different impact velocities, impact angles, particle sizes and particle shapes, and set multiple test angles.

3. The method for testing the wear of large-diameter slag in a shield tunnel grout discharge pipeline according to claim 1, characterized in that, The initial weight of the slag particles before the wear test is recorded. The slag particles are then fed into the slag drop pipe through a feeding funnel for the wear test. The remaining weight of the slag particles after the wear test is recorded, and the wear rate of the test target is calculated. The wear test results include: S41. Weigh and record the initial weight of the slag particles before the wear test. Place the slag particles into the feeding funnel. After the preset test time is reached, remove the test target from the target fixture. S42. Weigh the remaining weight of the test target using a weighing instrument, and calculate the wear mass of the test target in combination with the initial weight of the test target. S43. When the wear mass of the test target material reaches the wear threshold, weigh the remaining mass of the slag particles, record the total used mass of the slag particles, and calculate the wear rate of the test target material.

4. The method for testing the wear of large-diameter slag in a shield tunnel grout discharge pipeline according to claim 3, characterized in that, The wear thresholds include the wear threshold for spherical particles, the wear threshold for triangular prism particles, and the wear threshold for flat particles. The wear mass of the test target is the difference between the initial weight of the test target and the remaining weight of the test target. The total usable mass of the slag particles is the difference between the initial weight of the slag particles and the remaining mass of the slag particles. The wear rate of the test target is the ratio of the wear mass of the test target to the total used mass of the slag particles.

5. The method for testing the wear of large-diameter slag in a shield tunnel grout discharge pipeline according to claim 1, characterized in that, The process involves adjusting the wear test parameters and repeating steps S1-S4. Based on the wear test results, curves showing the changes in impact velocity, impact angle, particle size, particle shape, and wear rate of the test target are plotted. A particle size function and an impact angle function are then established based on these curves. Finally, the wear model of the test target is obtained by fitting the curves using these functions. Includes the following steps: S51. By adjusting different impact speeds, impact angles, particle sizes and particle shapes, repeat steps S1-S4 to obtain several wear test results. S52. Based on the wear test results, plot the curves showing the changes in impact velocity, impact angle, particle size, particle shape, and wear rate of the test target. S53. Based on the variation curve, determine the functional form of the wear model of the test target, including the particle size function, impact angle function, velocity exponent and shape factor; S54. Based on the wear rate variation curve of the test target and the functional form of the wear model of the test target, establish the wear model of the test target using mathematical modeling tools.

6. The method for testing the wear of large-diameter slag in a shield tunnel grout discharge pipeline according to claim 5, characterized in that, The expression for the particle size function is: f(dp) = A·dp + B In the formula, f(d) p ) represents the particle size function, A represents the first constant, and d p represents the particle size of the slag stone, and B represents the second constant; The expression for the impact angle function is: In the formula, f(θ) represents the impact angle function, θ represents the magnitude of the impact angle, and D i This represents the third constant during the i-th fitting; The expression for the wear model of the test target is: R=C·f ( dp ) f ( θ ) vb(v) In the formula, R represents the erosion wear rate, C represents the shape coefficient, v represents the particle velocity of the slag, and b(v) represents the velocity index.

7. The method for testing the wear of large-diameter slag in a shield tunnel grout discharge pipeline according to claim 1, characterized in that, The process of compiling the dynamic link library file of the test target wear model based on the integrated development environment, establishing simulated working conditions through discrete element simulation software, and correcting the test target wear model using model correction coefficients includes the following steps: S61. Based on the integrated development environment, create a new project file and compile the header and source files of the test target wear model, and copy them to the directory of the new project file; S62. Add code files to the new project file and compile them to generate a dynamic link library file for the test target wear model; S63. Use discrete element simulation software to set the contact model parameters between particles and geometry, load the dynamic link library file of the test target wear model, establish the simulated working condition, and use the model correction coefficient to correct the test target wear model. The model correction coefficient is the ratio of the actual thickness loss of the pipeline to the numerically calculated thickness loss.

8. A test device for abrasion of large-diameter slag in a shield tunnel grout discharge pipeline, used to implement the test method for abrasion of large-diameter slag in a shield tunnel grout discharge pipeline as described in any one of claims 1-7, characterized in that, The large-diameter slag abrasion test device for the shield tunnel grout discharge pipeline includes a feeding funnel; The bottom of the feeding funnel is provided with a slag and stone falling pipe. A pipe support is provided on the outside of the slag and stone falling pipe. Several pipe clamps that cooperate with the slag and stone falling pipe are provided in the middle of the pipe support. A box-shaped support is provided at the bottom of the pipe support. A target clamp is provided on the inside of the box-shaped support. The bottom of the slag and stone falling pipe is aligned with the center of the target clamp. A slag and stone collection box is provided at the bottom of the box-shaped support.

9. The shield tunnel grout discharge pipeline large-diameter slag abrasion test device according to claim 8, characterized in that, The slag and stone drop pipe is used in conjunction with the feeding funnel to feed slag and stone particles. The pipe support is used to fix the slag falling pipe and to change the height of the slag falling pipe by means of pipe clamps, so as to adjust the speed of the slag particles impacting the test target. The target clamp is used to fix the test target; The slag collection box is used to collect slag particles after the abrasion test; The box-shaped bracket is used to adjust the tilt angle of the target clamp, thereby enabling adjustment of multiple test angles.

10. The shield tunnel grout discharge pipeline large-diameter slag abrasion test device according to claim 9, characterized in that, The top of the target clamp is provided with several target limiting bolts, and several limiting holes are symmetrically opened on both sides of the box-shaped bracket. Screws are provided through the limiting holes on both sides of the target clamp. The target limiting bolt is used to fix the position of the test target. The screw is used to adjust and fix the tilt angle of the target clamp in conjunction with the limiting hole.

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