A method for reinforcing a line during a jacking process of a special-shaped box culvert

Abstract

The application discloses a method for reinforcing an existing line in a special-shaped box culvert jacking process, and relates to the technical field of existing line reinforcement, which comprises the following steps: S1, a worker determines the area needing line reinforcement according to the construction drawing requirements; S2, special-shaped box culvert jacking construction preparation work is carried out according to the construction area; S3, special-shaped box culvert jacking work is carried out after the preparation work is completed, and the existing line is reinforced in the jacking process; S4, the existing line in the jacking process is monitored in real time, and the special-shaped box culvert is timely treated and adjusted according to the monitoring result; and S5, when the special-shaped box culvert is jacked to the target position, final inspection and acceptance work are carried out. The application focuses on the research of the line reinforcement system, fully guarantees the smooth operation of trains and pipelines in the frame bridge underpass construction process, improves the safety and quality management level of the project, and provides a better guiding role for subsequent similar projects.

Description

Technical Field

[0001] This invention relates to the field of existing railway line reinforcement technology, and more specifically, to a method for reinforcing existing railway lines during the jacking process of irregular-shaped box culverts. Background Technology

[0002] With the rapid development of urban construction, transportation volume is also constantly increasing. When existing railways and highways intersect at grade, the common practice is to build a frame bridge under the existing railway to alleviate traffic congestion caused by the railway line passing through the city. Box culvert jacking refers to the construction of underground passages in areas with existing railway lines, using a jacking method to push the box culvert from the surface into the ground to avoid affecting the normal operation of the existing line. This engineering method is prone to causing deformation of the existing track, thus affecting train operation. Therefore, research on track deformation caused by box culvert jacking under existing lines has become particularly important.

[0003] The existing method is to demolish the old frame bridge while jacking one or more box sections that make up the main body of the frame bridge under the existing railway from one or both sides. In order not to affect the normal operation and safety of the existing railway, the existing railway at the jacking point must be reinforced before the box section is jacked in. At present, the main method is to use rail fastening reinforcement.

[0004] During reinforcement, the existing concrete sleepers in the area affected by the jacking are first replaced with wooden sleepers. The replacement is carried out according to the principle of leaving one concrete sleeper for every three wooden sleepers. The center-to-center spacing of the sleepers is controlled to be no more than 0.9m. After all the sleepers in the area have been replaced as required, personnel are organized to insert the I-beams, which serve as crossbeams, laterally under the existing railway. Before inserting them, personnel are organized to dig trenches in the existing track bed at the insertion point. The depth of the trenches is determined by the height of the I-beams. Finally, longitudinal beams are installed on both sides of the existing railway.

[0005] The conventional reinforcement construction method has the following problems:

[0006] 1) Because the existing railway tracks require lateral support, it is necessary to set up two end supports for the lateral support. During the jacking process, a section of lateral support is jacked up and then a section of lateral support is removed.

[0007] 2) Because this method is used to replace the sleepers on existing railway lines, the construction risks are high and the construction time is long, which will inevitably increase the risk to personnel and train safety.

[0008] 3) Since the trenching depth must ensure that the crossbeam can pass through, the depth is generally no less than 61cm from the bottom of the rail downwards, and it must be done manually. Therefore, the trenching work is large and the intensity is high. At the same time, due to the influence of passing trains, the ballast on the edge of the trench will roll into the trench after being vibrated, resulting in repeated work.

[0009] 4) Because the space reserved in this form is relatively small, if the box body tilts up during the jacking process, it will be impossible to deal with it effectively, thus directly affecting the stability of the existing line.

[0010] No effective solutions have yet been proposed to address the problems in the relevant technologies. Summary of the Invention

[0011] (a) Technical problems to be solved

[0012] To address the shortcomings of existing technologies, this invention provides a method for reinforcing existing railway lines during the jacking process of irregularly shaped box culverts. This method aims to improve the safety and quality management of projects, thereby solving the problems of high construction risks, large workload, and high intensity.

[0013] (II) Technical Solution

[0014] To achieve the aforementioned goal of improving the safety and quality management level of projects, the specific technical solution adopted by this invention is as follows:

[0015] A method for reinforcing existing railway lines during the jacking process of irregularly shaped box culverts, the method comprising the following steps:

[0016] S1. Staff members determine the areas that need to be reinforced based on the construction drawings.

[0017] S2. Prepare for the jacking construction of irregular box culverts according to the construction area;

[0018] S3. After the preparatory work is completed, carry out the jacking work of the irregular box culvert and reinforce the existing line during the jacking process;

[0019] S4. Monitor the existing track in real time during the jacking process, and promptly handle and adjust the irregular box culverts based on the monitoring results;

[0020] S5. After the irregular box culvert is jacked to the target position, the final inspection and acceptance work shall be carried out.

[0021] Furthermore, the preparatory work for the jacking construction of irregular box culverts according to the construction area includes the following steps:

[0022] S21. Select the jacking method based on the construction plan proposed in the design documents and the site conditions, and investigate the conditions of the jacking location to formulate a jacking plan;

[0023] S22. Based on the conditions of the construction site, set up the jacking pit for the irregular box culvert on one side of the existing line subgrade.

[0024] S23. Construct the working pit slide plate according to the location of the working pit and the centerline position of the irregular box culvert;

[0025] S24. The sheet pile operation method is used to connect with the working pit slide plate to realize the construction of the back wall and complete the preparation work before jacking.

[0026] S25. Lay an isolation layer on the top surface of the sliding plate, precast reinforced concrete frame culvert body sections, and install jacking equipment;

[0027] S26. Grouting is used to reinforce the surrounding disturbed soil.

[0028] Furthermore, the step of carrying out the jacking operation of the irregular-shaped box culvert after the preparatory work is completed, and reinforcing the existing line during the jacking process, includes the following steps:

[0029] S31. After the preparation work for the irregular box culvert is completed, install the reinforcement structure according to the construction requirements;

[0030] S32. Calculate the bearing capacity of the reinforced structure based on the actual construction conditions on site;

[0031] S33. After the reinforcement structure is installed and adjusted, the jacking work of the irregular box culvert will begin.

[0032] Furthermore, after the preparation work for the irregular-shaped box culvert is completed, the installation of the reinforcement structure according to the construction requirements includes the following steps:

[0033] S311. Determine the jacking direction of the irregular box culvert according to the design requirements, and set a row of anti-movement piles with a diameter of 1.25 meters and a length of 3 meters in the jacking direction;

[0034] S312. A row of support piles with a diameter of 1.25 meters and a length of 8 meters shall be installed on one side of the anti-displacement pile;

[0035] S313. Several sets of crossbeams are installed at the top of the anti-displacement piles and support piles. One end of the crossbeam is connected to the anti-displacement pile, and two sets of longitudinal beams are bolted to the top of the middle of the crossbeam.

[0036] S314. The other end of the crossbeam is placed on top of the irregular box culvert as a movable fulcrum, forming an overall stiffness enhancement of the upper longitudinal and transverse beams, and the lower support pile box culvert provides support for the system line reinforcement method.

[0037] Furthermore, the calculation of the load-bearing capacity of the reinforced structure based on the actual on-site construction conditions includes the following steps:

[0038] S321. Collect on-site investigation reports related to the reinforced structure, and determine the loads acting on the reinforced structure based on the on-site reports;

[0039] S322. Based on the site survey report, calculate the strength and stiffness of the beams in the existing reinforced structure;

[0040] S323. Verify the safety factor of the reinforced structure based on the calculation results and construction requirements;

[0041] S324. Adjust the reinforced structure based on the verification results.

[0042] Furthermore, based on the site survey report, the calculation formulas for the strength and stiffness of the beams in the existing reinforced structure are as follows:

[0043]

[0044]

[0045] In the formula, M represents the strength of the beam, P represents the uniformly distributed static load, β represents the speed-limiting reduction rate, μ represents the impact coefficient, and L... P denoted by f, which represents the calculated span of the crossbeam; f represents the stiffness of the crossbeam; q represents the converted uniformly distributed live load; E represents the elastic modulus of the rail; I represents the moment of inertia of the rail; and n represents the number of crossbeams.

[0046] Furthermore, the safety factor verification of the reinforced structure based on the calculation results and construction requirements includes the following steps:

[0047] S3231. The safety factor of the existing lines at the construction site is obtained using the limit equilibrium theory.

[0048] S3232. Establish a probabilistic model for the safety factor and reinforcement structure of the existing line, and construct the safe and realistic load equations of the existing line using Monte Carlo simulation and response surface methodology respectively.

[0049] S3233. Use FORM to calculate the reliability indicators for the safety of existing lines;

[0050] S3234. The design method provided by the construction requirements is calibrated, and the limit state equation of the fixed structure is generated based on the overall safety factor design formula of the code to obtain its reliability index.

[0051] Furthermore, the adjustment of the reinforced structure based on the verification results includes the following steps:

[0052] S3241. Based on the verification results, determine the specific problems existing in the reinforced structure, wherein the problems include insufficient strength and stiffness of the beams, the number of beams, and the location of the beams.

[0053] S3242. Based on the analysis of the verification results, determine the specific targets that need to be adjusted and optimize the design scheme of the reinforced structure;

[0054] S3243. Use structural analysis software to perform simulation analysis and evaluate the performance of the adjusted reinforced structure.

[0055] S3244. Conduct acceptance inspection of the adjusted reinforced structure.

[0056] Furthermore, the real-time monitoring of the existing track during the jacking process, and the timely handling and adjustment of irregular box culverts based on the monitoring results, includes the following steps:

[0057] S41. Install monitoring equipment on existing lines and the jacking path of irregular box culverts, and pre-set the direction and elevation during the jacking process of irregular box culverts;

[0058] S42. Based on the monitoring data output by the monitoring equipment, monitor the direction and elevation of the irregular box culvert during the jacking process in real time;

[0059] S43. When the monitoring results exceed the predetermined movement range and height, an early warning shall be issued and the jacking operation shall be stopped.

[0060] S44. Adjust the jacking direction and elevation of the irregular box culvert according to the cause of the warning.

[0061] Furthermore, adjusting the jacking direction and elevation of the irregular-shaped box culvert based on the cause of the early warning includes the following steps:

[0062] S441. If the warning is due to the jacking direction, conduct an investigation of the irregular box culvert and its surrounding area to determine the factors affecting the jacking direction, and formulate specific countermeasures based on the influencing factors. The countermeasures include adding lateral supports at the front end of the irregular box culvert and changing the construction direction.

[0063] S442. If the cause of the warning is elevation, use a total station to measure the elevation of the jacking position, and formulate a specific adjustment plan by analyzing the measurement data. The adjustment plan includes adding or reducing support equipment.

[0064] (III) Beneficial Effects

[0065] Compared with the prior art, the present invention provides a method for reinforcing existing railway lines during the jacking process of irregular-shaped box culverts, which has the following beneficial effects:

[0066] (1) This invention focuses on the research of the line reinforcement system to fully ensure the smooth operation of trains and pipelines during the construction of the frame bridge underpass. While ensuring quick and convenient construction, it summarizes a more mature and reliable line reinforcement system, improves the safety and quality management level of the project, and provides better guidance for similar projects in the future.

[0067] (2) The present invention controls the lateral and longitudinal deformation of the existing railway line, ensuring that the running speed and safety of the upper railway will not be affected during the construction process. Since the support point of one end of the rail beam is set on the upper part of the box culvert during the jacking process, and the support point is movable, the sliding friction is changed to rolling friction. Therefore, not only is the required jacking force reduced, but the construction time of traditional pile foundation demolition is also greatly reduced.

[0068] (3) This invention enables railway trains to operate normally during construction, reduces the impact on the surrounding environment, improves project efficiency, and ensures the reinforcement of existing lines during the jacking of irregular box culverts. By calculating the strength of the crossbeams, their bearing capacity is determined, enabling them to withstand greater loads and enhance the overall bearing capacity of the structure. The crossbeams provide rigid support, which can limit the deformation of the reinforced structure and improve the stability of the existing lines. Attached Figure Description

[0069] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0070] Figure 1 This is a flowchart illustrating the method for reinforcing existing railway lines during the jacking process of irregularly shaped box culverts according to an embodiment of the present invention.

[0071] Figure 2 This is a schematic diagram of the reinforcement structure according to an embodiment of the present invention;

[0072] Figure 3 yes Figure 2 A magnified view of a portion of point A in the middle. 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 for reinforcing existing railway lines during the jacking process of irregularly shaped box culverts is provided.

[0075] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments, such as... Figure 1As shown, the present invention relates to a method for reinforcing existing railway lines during the jacking process of irregularly shaped box culverts, comprising the following steps:

[0076] S1. Staff members determine the areas where line reinforcement is required based on the construction drawings.

[0077] S2. Prepare for the jacking construction of irregular box culverts according to the construction area.

[0078] In one embodiment, the preparation work for the jacking construction of irregular box culverts according to the construction area includes the following steps:

[0079] S21. Select the jacking method based on the construction plan proposed in the design documents and the site conditions, and investigate the conditions of the jacking location to formulate a jacking plan;

[0080] S22. Based on the conditions of the construction site, set up the jacking pit for the irregular box culvert on one side of the existing line subgrade.

[0081] S23. Construct the working pit slide plate according to the location of the working pit and the centerline position of the irregular box culvert;

[0082] S24. The sheet pile operation method is used to connect with the working pit slide plate to realize the construction of the back wall and complete the preparation work before jacking.

[0083] S25. Lay an isolation layer on the top surface of the sliding plate, precast reinforced concrete frame culvert body sections, and install jacking equipment;

[0084] S26. Grouting is used to reinforce the surrounding disturbed soil.

[0085] S3. After the preparatory work is completed, carry out the jacking work of the irregular box culvert and reinforce the existing line during the jacking process.

[0086] In one embodiment, the step of jacking up the irregular-shaped box culvert after the preparatory work is completed, and reinforcing the existing line during the jacking process, includes the following steps:

[0087] S31. After the preparation work for the irregular box culvert is completed, install the reinforcement structure according to the construction requirements.

[0088] It should be noted that a row of anti-displacement piles with a diameter of 1.25 meters and a length of 13 meters were installed in the direction of the box culvert's jacking. During the process of the box culvert passing under the railway, it is necessary to excavate while jacking. The box culvert is positioned directly under the railway, and uneven settlement of the railway is inevitable during the construction process.

[0089] To reduce the impact of excavation work during the box culvert jacking process on railway settlement, vertical support points are needed for the railway. Therefore, in addition to setting anti-displacement piles in the jacking direction, a row of support piles with a diameter of 1.25 meters and a length of 8 meters is installed below the railway. To reduce uneven settlement during construction and improve the overall integrity of the railway, this invention adopts a rail fastening + longitudinal and transverse beam reinforcement system and a bridge jacking construction process. The reinforcement length for both lines is 125 meters.

[0090] like Figure 2 and Figure 3 As shown, in this embodiment, the reinforcement structure proposed by the present invention requires the following structure during use:

[0091] Anti-displacement pile I, support pile II, crossbeam III, longitudinal beam IV, irregular box culvert V, and rail fastening VI.

[0092] One end of the crossbeam is supported on the anti-displacement piles and support piles on the west side of the line, while the other end still needs a support point. Since all the pile foundations on the box culvert jacking line need to be removed, setting up piles on the roadside to provide a support point would not only be very costly, but would also affect the railway during the process of removing the pile foundations during the box culvert jacking. After removal, the crossbeam cannot be supported. Therefore, the line reinforcement scheme of this invention adopts a pile support at one end and a movable support point at the other end to support the top plate of the box culvert.

[0093] Ultimately, a system was adopted where one end is supported on anti-movement piles and support piles, and the other end is placed on top of the box culvert as a movable fulcrum. The longitudinal beams are all connected to the transverse beams with bolts, forming a system for strengthening the overall rigidity of the upper longitudinal and transverse beams and providing support for the lower support piles and box culvert.

[0094] Specifically, after the preparation work for the irregular-shaped box culvert is completed, the installation of the reinforcement structure according to the construction requirements includes the following steps:

[0095] S311. Determine the jacking direction of the irregular box culvert according to the design requirements, and set a row of anti-movement piles with a diameter of 1.25 meters and a length of 3 meters in the jacking direction;

[0096] S312. A row of support piles with a diameter of 1.25 meters and a length of 8 meters shall be installed on one side of the anti-displacement pile;

[0097] S313. Several sets of crossbeams are installed at the top of the anti-displacement piles and support piles. One end of the crossbeam is connected to the anti-displacement pile, and two sets of longitudinal beams are bolted to the top of the middle of the crossbeam.

[0098] S314. The other end of the crossbeam is placed on top of the irregular box culvert as a movable fulcrum, forming an overall stiffness enhancement of the upper longitudinal and transverse beams, and the lower support pile box culvert provides support for the system line reinforcement method.

[0099] S32. Calculate the load-bearing capacity of the reinforced structure based on the actual construction conditions on site.

[0100] Specifically, the calculation of the load-bearing capacity of the reinforced structure based on the actual on-site construction conditions includes the following steps:

[0101] S321. Collect on-site investigation reports related to the reinforced structure, and determine the loads acting on the reinforced structure based on the on-site reports;

[0102] S322. Based on the site survey report, calculate the strength and stiffness of the beams in the existing reinforced structure.

[0103] The calculation formula for the strength and stiffness of the beams in the existing reinforced structure, based on the site survey report, is as follows:

[0104]

[0105]

[0106] In the formula, M represents the strength of the beam, P represents the uniformly distributed static load, β represents the speed-limiting reduction rate, μ represents the impact coefficient, and L... P denoted by f, which represents the calculated span of the crossbeam; f represents the stiffness of the crossbeam; q represents the converted uniformly distributed live load; E represents the elastic modulus of the rail; I represents the moment of inertia of the rail; and n represents the number of crossbeams.

[0107] S323. Based on the calculation results and construction requirements, the safety factor of the reinforced structure shall be checked.

[0108] Specifically, the safety factor check of the reinforced structure based on the calculation results and construction requirements includes the following steps:

[0109] S3231. The safety factor of the existing line at the construction site is obtained by using the limit equilibrium theory.

[0110] Using limit equilibrium theory to assess the safety factor of existing power lines is a common method.

[0111] The process of obtaining the safety factor of existing power lines at the construction site using limit equilibrium theory may include the following steps:

[0112] Collect relevant parameters of the line, including the line's load conditions, the mechanical properties of the structural materials, and the line's geometry;

[0113] Determine the boundary conditions of the line, including the stability of the supporting structure and the bearing capacity of the foundation soil;

[0114] Based on the geometry and load conditions of the line, draw force analysis diagrams, including force diagrams, bending moment diagrams, shear force diagrams, etc.

[0115] Using the limit equilibrium theory and force analysis diagrams, the safety factor for each part of the railway line is calculated. The safety factor is the ratio between the actual bearing capacity of each critical part of the line and the maximum load it receives.

[0116] Based on the calculation results, the safety factor of the line is evaluated. Generally speaking, the higher the safety factor, the higher the safety of the line.

[0117] S3232. Establish a probabilistic model for the safety factor and reinforcement structure of the existing line, and construct the safe and realistic load equations of the existing line using Monte Carlo simulation and response surface methodology, respectively.

[0118] Specifically, Monte Carlo simulation is a random sampling method used to estimate the results of uncertain problems. When establishing a probabilistic model of the safety factor and reinforcement structure of an existing line, Monte Carlo simulation can be used to generate random variables, such as load size and material strength. Through multiple simulations, the distribution of the safety factor can be calculated, thus obtaining a set of probability distributions of the safety factor, thereby evaluating the reliability of the line and the effectiveness of the reinforcement structure.

[0119] Response surface methodology (RSM) is a mathematical modeling method that predicts output results by constructing a mathematical relationship between input variables and output response. When establishing a probabilistic model for the safety factor and reinforcement structure of existing power lines, RSM can be used to construct the safety load equation for existing power lines. By designing appropriate experiments, collecting safety factor data of the power lines under different load conditions, and fitting the response surface model, an approximate safety load equation can be obtained. In this way, the safety of the power lines can be evaluated by calculating the safety load equation under given load conditions.

[0120] S3233. Use FORM to calculate the reliability index of the safety of existing lines.

[0121] Specifically, the FORM (First Order Reliability Method) can be used to calculate the reliability index of existing lines. FORM is a commonly used reliability analysis method used to evaluate the reliability of a system under given design conditions.

[0122] The calculation of reliable indicators for the safety of existing lines using FORM includes the following steps:

[0123] First, it is necessary to clarify the reliability indicators to be evaluated, such as the safety factor of the line. The safety factor is the ratio between the actual load-bearing capacity of the line structure and the maximum load it receives.

[0124] Mathematical models are used to model various parameters and variables that affect the safety factor of the line, and their probability distributions are determined. For example, variables such as load size and material strength can be modeled as random variables.

[0125] The limit state function is a function used to describe whether the system state meets the reliability index. In this case, the limit state function can be defined as the difference between the line safety factor and a certain predetermined safety threshold.

[0126] FORM calculations can determine the design conditions required to achieve the specified reliability index. The FORM method is based on the first-order Taylor expansion. Through iterative calculations, the design conditions that make the limit state function equal to zero are found, which are the design conditions that meet the reliability requirements.

[0127] Based on the results of the FORM calculations, design conditions that meet reliability requirements can be obtained. For existing lines, it can be assessed whether reinforcement or other measures are needed to improve the line's safety.

[0128] S3234. The design method provided by the construction requirements is calibrated, and the limit state equation of the fixed structure is generated based on the overall safety factor design formula of the code to obtain its reliability index.

[0129] S324. Adjust the reinforced structure based on the verification results.

[0130] Specifically, the adjustment of the reinforced structure based on the verification results includes the following steps:

[0131] S3241. Based on the verification results, determine the specific problems existing in the reinforced structure, wherein the problems include insufficient strength and stiffness of the beams, the number of beams, and the location of the beams.

[0132] S3242. Based on the analysis of the verification results, determine the specific targets that need to be adjusted and optimize the design scheme of the reinforced structure;

[0133] S3243. Use structural analysis software to perform simulation analysis and evaluate the performance of the adjusted reinforced structure.

[0134] S3244. Conduct acceptance inspection of the adjusted reinforced structure.

[0135] S33. After the reinforcement structure is installed and adjusted, the jacking work of the irregular box culvert will begin.

[0136] S4. Monitor the existing track in real time during the jacking process, and promptly handle and adjust irregular box culverts based on the monitoring results.

[0137] In one embodiment, the real-time monitoring of the existing line during the jacking process, and the timely handling and adjustment of the irregular box culvert based on the monitoring results, includes the following steps:

[0138] S41. Install monitoring equipment on existing lines and the jacking path of irregular box culverts, and pre-set the direction and elevation during the jacking process of irregular box culverts;

[0139] S42. Based on the monitoring data output by the monitoring equipment, monitor the direction and elevation of the irregular box culvert during the jacking process in real time;

[0140] S43. When the monitoring results exceed the predetermined movement range and height, an early warning shall be issued and the jacking operation shall be stopped.

[0141] S44. Adjust the jacking direction and elevation of the irregular box culvert according to the cause of the warning.

[0142] The adjustment of the jacking direction and elevation of the irregular box culvert based on the cause of the early warning includes the following steps:

[0143] S441. If the warning is due to the jacking direction, conduct an investigation of the irregular box culvert and its surrounding area to determine the factors affecting the jacking direction, and formulate specific countermeasures based on the influencing factors. The countermeasures include adding lateral supports at the front end of the irregular box culvert and changing the construction direction.

[0144] S442. If the cause of the warning is elevation, use a total station to measure the elevation of the jacking position, and formulate a specific adjustment plan by analyzing the measurement data. The adjustment plan includes adding or reducing support equipment.

[0145] S5. After the irregular box culvert is jacked to the target position, the final inspection and acceptance work shall be carried out.

[0146] In summary, by utilizing the above-mentioned technical solutions of this invention, the present invention focuses on the research of a railway line reinforcement system, fully ensuring the smooth operation of trains and pipelines during the construction of the frame bridge underpass. While ensuring quick and convenient construction, it summarizes a more mature and reliable railway line reinforcement system, improving the safety and quality management level of the project and providing better guidance for subsequent similar projects. This invention controls the lateral and longitudinal deformation of the existing railway line, ensuring that the operating speed and safety of the upper railway are not affected during construction. Because one end of the rail beam is supported on the upper part of the box culvert during the jacking process, and this support is movable, sliding friction is changed to rolling friction, thus reducing not only the required jacking force but also significantly reducing the construction time of traditional pile foundation removal. This invention enables the normal operation of railway trains during construction, reducing the impact on the surrounding environment and improving project efficiency. Simultaneously, it ensures the reinforcement of the existing line during the jacking of the irregular box culvert. By calculating the strength of the beam to determine its bearing capacity, it can withstand greater loads, enhancing the overall bearing capacity of the structure. The rigid support provided by the beam can limit the deformation of the reinforced structure, improving the stability of the existing line.

[0147] 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 reinforcing existing railway lines during the jacking process of irregularly shaped box culverts, characterized in that, The reinforcement method includes the following steps: S1. Staff members determine the areas that need to be reinforced based on the construction drawings. S2. Prepare for the jacking construction of irregular box culverts according to the construction area; S3. After the preparatory work is completed, carry out the jacking work of the irregular box culvert and reinforce the existing line during the jacking process; S4. Monitor the existing track in real time during the jacking process, and promptly handle and adjust the irregular box culverts based on the monitoring results; S5. After the irregular box culvert is jacked to the target position, the final inspection and acceptance work shall be carried out. The process of jacking up the irregular-shaped box culvert after the preparatory work is completed, and reinforcing the existing line during the jacking process, includes the following steps: S31. After the preparation work for the irregular box culvert is completed, install the reinforcement structure according to the construction requirements; S32. Calculate the load-bearing capacity of the reinforced structure based on the actual construction conditions on site; S33. After the reinforcement structure is installed and adjusted, the jacking work of the irregular box culvert will begin. After the preparation work for the irregular-shaped box culvert is completed, the installation of the reinforcement structure according to the construction requirements includes the following steps: S311. Determine the jacking direction of the irregular box culvert according to the design requirements, and set a row of anti-movement piles with a diameter of 1.25 meters and a length of 3 meters in the jacking direction; S312. A row of support piles with a diameter of 1.25 meters and a length of 8 meters shall be installed on one side of the anti-displacement pile; S313. Several sets of crossbeams are installed at the top of the anti-displacement piles and support piles. One end of the crossbeam is connected to the anti-displacement pile, and two sets of longitudinal beams are bolted to the top of the middle of the crossbeam. S314. The other end of the crossbeam is placed on top of the irregular box culvert as a movable fulcrum, forming an overall stiffness enhancement of the upper longitudinal and transverse beams, and the lower support pile box culvert provides support for the system line reinforcement method.

2. The method for reinforcing existing railway lines during the jacking process of an irregularly shaped box culvert according to claim 1, characterized in that, The preparatory work for the jacking construction of irregular box culverts according to the construction area includes the following steps: S21. Select the jacking method based on the construction plan proposed in the design documents and the site conditions, and investigate the conditions of the jacking location to formulate a jacking plan; S22. Based on the conditions of the construction site, set up the jacking pit for the irregular box culvert on one side of the existing line subgrade. S23. Construct the working pit slide plate according to the location of the working pit and the centerline position of the irregular box culvert; S24. The sheet pile operation method is used to connect with the working pit slide plate to realize the construction of the back wall and complete the preparation work before jacking. S25. Lay an isolation layer on the top surface of the sliding plate, precast reinforced concrete frame culvert body sections, and install jacking equipment; S26. Grouting is used to reinforce the surrounding disturbed soil.

3. The method for reinforcing existing railway lines during the jacking process of an irregularly shaped box culvert according to claim 1, characterized in that, The calculation of the load-bearing capacity of the reinforced structure based on the actual on-site construction conditions includes the following steps: S321. Collect on-site investigation reports related to the reinforced structure, and determine the loads acting on the reinforced structure based on the on-site reports; S322. Based on the site survey report, calculate the strength and stiffness of the beams in the existing reinforced structure; S323. Verify the safety factor of the reinforced structure based on the calculation results and construction requirements; S324. Adjust the reinforced structure based on the verification results.

4. The method for reinforcing existing railway lines during the jacking process of an irregularly shaped box culvert according to claim 3, characterized in that, According to the site survey report, the calculation formulas for the strength and stiffness of the beams in the existing reinforced structure are as follows: In the formula, Indicates the strength of the beam. Indicates uniformly distributed static load. Indicates the speed limit reduction rate. Indicates the impact coefficient. This indicates the calculated span of the beam. Indicates the stiffness of the beam. This indicates the conversion to uniformly distributed live load. This indicates the elastic modulus of the rail. Indicates the moment of inertia of the rail. This indicates the number of beams.

5. A method for reinforcing existing railway lines during the jacking process of an irregularly shaped box culvert according to claim 4, characterized in that, The safety factor verification of the reinforced structure based on the calculation results and construction requirements includes the following steps: S3231. The safety factor of the existing lines at the construction site is obtained using the limit equilibrium theory. S3232. Establish a probabilistic model for the safety factor and reinforcement structure of the existing line, and construct the safe and realistic load equations of the existing line using Monte Carlo simulation and response surface methodology respectively. S3233. Use FORM to calculate the reliability indicators for the safety of existing lines; S3234. The design method provided by the construction requirements is calibrated, and the limit state equation of the fixed structure is generated based on the overall safety factor design formula of the code to obtain its reliability index.

6. A method for reinforcing existing railway lines during the jacking process of an irregularly shaped box culvert according to claim 5, characterized in that, The adjustment of the reinforced structure based on the verification results includes the following steps: S3241. Based on the verification results, determine the specific problems existing in the reinforced structure, wherein the problems include insufficient strength and stiffness of the beams, the number of beams, and the location of the beams. S3242. Based on the analysis of the verification results, determine the specific targets that need to be adjusted and optimize the design scheme of the reinforced structure; S3243. Use structural analysis software to perform simulation analysis and evaluate the performance of the adjusted reinforced structure. S3244. Conduct acceptance inspection of the adjusted reinforced structure.

7. The method for reinforcing existing railway lines during the jacking process of an irregularly shaped box culvert according to claim 1, characterized in that, The real-time monitoring of the existing line during the jacking process, and the timely handling and adjustment of irregular box culverts based on the monitoring results, includes the following steps: S41. Install monitoring equipment on existing lines and the jacking path of irregular box culverts, and pre-set the direction and elevation during the jacking process of irregular box culverts; S42. Based on the monitoring data output by the monitoring equipment, monitor the direction and elevation of the irregular box culvert during the jacking process in real time; S43. When the monitoring results exceed the predetermined movement range and height, an early warning shall be issued and the jacking operation shall be stopped. S44. Adjust the jacking direction and elevation of the irregular box culvert according to the cause of the warning.

8. A method for reinforcing existing railway lines during the jacking process of an irregularly shaped box culvert according to claim 7, characterized in that, The adjustment of the jacking direction and elevation of the irregular box culvert based on the cause of the early warning includes the following steps: S441. If the warning is due to the jacking direction, conduct an investigation of the irregular box culvert and its surrounding area to determine the factors affecting the jacking direction, and formulate specific countermeasures based on the influencing factors. The countermeasures include adding lateral supports at the front end of the irregular box culvert and changing the construction direction. S442. If the cause of the warning is elevation, use a total station to measure the elevation of the jacking position, and formulate a specific adjustment plan by analyzing the measurement data. The adjustment plan includes adding or reducing support equipment.

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