A method for quickly replacing metro ballastless track sleepers by directional micro-damage splitting

Abstract

A rapid replacement method for subway ballastless track sleepers using directional micro-damage splitting, relating to the field of sleeper replacement technology, includes scanning the target sleeper and underlying track bed, identifying the location of reinforcing bars, and constructing a building information model (BIM) containing the sleeper and track bed structure; inputting sleeper damage data into the BIM to obtain a splitting drilling scheme; drilling splitting holes on the sleeper according to the splitting drilling scheme, inserting splitting heads into the splitting holes and performing gradient pressure to ultimately form an isolation joint; drilling grid-distributed fracture holes on the isolated sleeper and splitting it into multiple fragments before removing it to form a sleeper pit; laying a mortar layer in the sleeper pit, hoisting and precisely positioning a new sleeper, followed by grouting; and using a zoned microwave emission array to intelligently temperature-controlled cure the newly poured mortar and grouting material. This method addresses the problems of traditional replacement methods causing significant damage to the track bed structure and low replacement efficiency.

Description

Technical Field

[0001] This invention relates to the field of sleeper replacement technology, and specifically to a method for rapid replacement of subway ballastless track sleepers using directional micro-damage splitting. Background Technology

[0002] As a crucial component of urban rail transit, the ballastless track of subways plays a vital role in transmitting train loads and maintaining track geometry. With increasing operating time, concrete sleepers are prone to cracking, spalling, and steel reinforcement corrosion due to long-term train impacts, environmental erosion, and material aging. These defects severely impact track structural safety and train operational stability, necessitating timely replacement.

[0003] However, existing technologies face several serious challenges in replacing sleepers on subway ballastless tracks:

[0004] First, the working space is extremely limited; about 70% of the subway line is a tunnel section, and the inner diameter of the tunnel is usually only 5.5-6 meters. The tunnel is equipped with ancillary facilities such as contact rails and cable troughs. The large equipment such as medium-sized track-changing cars and track cranes used in traditional railway sleeper replacement cannot enter the tunnel for operation. The vast majority of defects can only be treated by manual labor combined with small machinery, which is inefficient and labor-intensive.

[0005] Secondly, the construction window is extremely tight; subway operations need to ensure normal daytime service, and construction can usually only be carried out during fragmented window periods of 2-3 hours at night, with a safety margin of safety required. Traditional sleeper replacement processes rely on natural curing or conventional mechanical tamping, which are time-consuming and cannot meet the tight coordination requirements of subway operations and maintenance.

[0006] Third, the track bed structure is easily damaged. To enhance its resistance to settlement, subway ballastless track beds generally adopt a dense steel reinforcement design. Existing sleeper replacement methods mostly rely on manual removal of track bed materials using tools such as electric hammers, which can easily cause deformation or damage to the internal steel reinforcement. This not only affects the integrity of the track bed structure but may also lead to subsequent settlement or changes in track geometry, increasing maintenance costs and safety risks.

[0007] Therefore, we propose a method that enables rapid and precise replacement while maximizing the protection of the track bed structure. Summary of the Invention

[0008] The purpose of this invention is to provide a method for rapid replacement of subway ballastless track sleepers using directional micro-damage splitting, which solves the problems of traditional replacement methods causing great damage to the track bed structure and low replacement efficiency.

[0009] This invention is achieved through the following technical solution:

[0010] A method for rapid replacement of subway ballastless track sleepers using directional micro-damage splitting, specifically including:

[0011] Scan the target sleeper and the underlying track bed to identify the location of the reinforcing bars and construct a building information model that includes the sleeper and track bed structure;

[0012] Input sleeper damage data into the building information model to obtain a splitting borehole scheme;

[0013] According to the splitting drilling scheme, splitting holes are drilled on the sleeper, a splitting head is inserted into the splitting hole and gradient pressure is applied to make the cracks extend directionally along the interface between the sleeper and the track bed, and finally an annular isolation joint is formed around the sleeper to separate it from the track bed.

[0014] Drill a grid of break holes on the isolated sleeper and split it to break it into multiple pieces. Remove the pieces to form a sleeper pit and then flatten the bottom surface of the sleeper pit.

[0015] A mortar layer is laid in the sleeper pit, a new sleeper is hoisted and precisely positioned, and then grouting is performed;

[0016] A zoned microwave emission array is used to intelligently temperature-controlled cure the newly poured mortar and grout.

[0017] Furthermore, the process of scanning the target sleeper and its underlying track bed, identifying the location of the reinforcing bars, and constructing a building information model including the sleeper and track bed structure is as follows:

[0018] A 1.5GHz center frequency multibeam ground-penetrating radar was used to perform a linear trajectory uniform speed scan on the target sleeper and its underlying track bed to generate a B-scan track bed profile image.

[0019] The hyperbolic reflection characteristics of the reinforcing bars in the image are identified by the Hough transform algorithm. The embedment depth of the reinforcing bars is calculated and mapped to the BIM coordinate system. Combined with the built-in 3D sleeper model in BIM, the physical boundary of the sleeper and the boundary of the track bed structure are automatically distinguished to form a building information model that includes both the sleeper and the track bed structure.

[0020] Furthermore, the scanning path adopts a serpentine trajectory, or a combination of longitudinal main scan and lateral rescan.

[0021] Furthermore, an array of acoustic emission sensors is installed on the sleeper to monitor the energy value of crack propagation in real time. When the energy value exceeds the threshold, the splitting device is controlled to perform pressure reduction or pressure stop operation.

[0022] Furthermore, the contact portion between the splitting head and the sleeper of the splitting hole is wedge-shaped.

[0023] Furthermore, the wedge angle is 8°-13°.

[0024] Furthermore, the gradient pressurization specifically includes three stages: the first stage is to slowly initiate cracking with pressure below a set pressure threshold; the second stage is to gradually increase the pressure to allow the crack to extend stably to the surface of the track bed; and the third stage is to increase the pressure again to allow the crack to completely penetrate and form the isolation joint.

[0025] Furthermore, the grid-like distribution of the break holes is arranged in an m-row × n-column matrix, where m and n are both integers greater than or equal to 2, and the sleeper is broken into more than m × n blocks by sequential splitting.

[0026] Furthermore, the intelligent temperature control maintenance specifically involves: using temperature sensors buried at different depths to provide real-time temperature feedback;

[0027] The control platform dynamically adjusts the power of the microwave transmitter in the corresponding area based on the temperature feedback, so that the temperature in the maintenance area is maintained within a constant preset range.

[0028] Furthermore, during the hoisting of the new sleepers, the tilt sensor communicates in real time with the building information model platform. The platform compares the real-time posture with the design parameters and drives the hoisting equipment to adjust the angle until the levelness error is less than the allowable value before the hoisting equipment can be placed in position.

[0029] The technical solution of the present invention has at least the following advantages and beneficial effects:

[0030] This invention discloses a rapid replacement method for subway ballastless track sleepers using directional micro-damage splitting. It integrates the entire process of "scanning modeling - scheme generation - directional splitting - mesh breaking - precise installation - intelligent maintenance", forming a complete solution that is highly adaptable to the narrow space and short-term skylights of subways. It can be implemented with only miniaturized and modular equipment, fundamentally solving the compatibility problem of large equipment being unable to enter the tunnel.

[0031] In addition, by forming annular isolation joints through directional splitting, the damage can be precisely controlled within the body of the sleeper to be replaced, and the cracks are forced to extend horizontally along the preset interface, maintaining the integrity and long-term load-bearing capacity of the track bed structure. Furthermore, by adopting the "break down into parts" strategy, the removal of large volumes of concrete becomes easy and convenient, greatly reducing the labor intensity of workers and facilitating the cleaning and transportation of fragments, further improving the efficiency of operations in confined spaces.

[0032] In addition, by using ground-penetrating radar of a specific frequency and an optimized scanning path, combined with the Hough transform image recognition algorithm, it is possible to identify and locate the hidden steel mesh in the track bed with high precision and efficiency, providing a reliable data foundation for subsequent "minimally damaged" construction and avoiding damage risks from the source.

[0033] Furthermore, by deploying an array of acoustic emission sensors and setting energy thresholds for real-time monitoring, dynamic closed-loop control of the splitting process is achieved. Once an energy surge indicating abnormal crack expansion is detected, the system can intervene immediately, effectively preventing the crack from accidentally penetrating the track bed and elevating construction safety from "human experience judgment" to "real-time data assurance". Attached Figure Description

[0034] Figure 1 This is a schematic diagram of a method for rapid replacement of subway ballastless track sleepers using directional micro-damage splitting according to the present invention.

[0035] Figure 2 This is a schematic diagram of a quick replacement system for subway ballastless track sleepers using directional micro-damage splitting according to the present invention.

[0036] Figure 3 This is a schematic diagram of the electronic device structure of the present invention. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0038] Example 1

[0039] like Figure 1 The method for rapid replacement of subway ballastless track sleepers using directional micro-damage splitting, as shown, specifically includes:

[0040] The target sleeper and underlying track bed are scanned to identify the location of the reinforcing steel and a building information model (BIM) containing the sleeper and track bed structure is constructed. The specific process is as follows:

[0041] A multi-beam ground-penetrating radar with a center frequency of 1.5 GHz was used to perform a linear trajectory uniform speed scan on the target sleeper and its underlying track bed to generate a B-scan track bed profile image.

[0042] Frequency selection is crucial. 1.5GHz is in the mid-to-high frequency band of ground penetrating radar. Its electromagnetic waves have good balance in concrete media, meaning it has sufficient penetration depth (up to tens of centimeters, meeting the needs of track bed detection) and high resolution, enough to distinguish small-diameter steel bars. The multi-beam design can be regarded as "multi-line parallel scanning", which can significantly improve scanning efficiency and data density compared to single beam. This is the core guarantee for adapting to the "short window" construction of subways.

[0043] In addition, the scanning path adopts a serpentine trajectory, or a combination of longitudinal main scan and lateral rescan, which is an optimization strategy for the scanning path. The serpentine trajectory ensures seamless coverage of the scanning area without any blind spots. The combination of longitudinal main scan and lateral rescan constitutes a simple "grid" data acquisition strategy. The longitudinal scan obtains the main profile, and the lateral rescan can not only verify the data, but also improve the accuracy of solving the direction and spatial position of the reinforcing bars through scanning data in different directions, thereby enhancing the reliability of the model.

[0044] The electromagnetic wave reflection signals received by ground penetrating radar are processed and arranged into a two-dimensional image, namely a B-scan image, according to the scanning order. It should be noted that in this image, the horizontal axis represents the horizontal scanning position, the vertical axis represents the depth, and the gray level or color represents the strength of the reflected signal. Point objects such as steel bars appear as a characteristic hyperbolic shape in the image, which is determined by the geometric diffusion and point reflection characteristics of the radar wave front.

[0045] The hyperbolic reflection characteristics of the reinforcing bars in the image are identified by the Hough transform algorithm, the embedment depth of the reinforcing bars is calculated and mapped to the BIM coordinate system;

[0046] The transformation algorithm is a classic algorithm for detecting specific geometric shapes (such as straight lines, circles, and hyperbolas) from images. Here, it is specifically used to automatically identify numerous hyperbolic reflection features of reinforcing bars in B-scan images. The algorithm can robustly find these characteristic hyperbolas amidst a host of clutter, such as reflections caused by concrete inhomogeneity and impurities. After identifying the vertices of the hyperbolas, the embedment depth of each reinforcing bar can be accurately calculated based on the propagation speed of electromagnetic waves in concrete. At the same time, combined with the precise positioning system of the scanning equipment (such as a total station or laser tracker), the horizontal position and depth information of each identification point are uniformly converted into the BIM coordinate system of the entire project, achieving a precise mapping from "image pixels" to "project 3D coordinates".

[0047] By combining the built-in 3D model of the sleeper in BIM, the physical boundary of the sleeper and the boundary of the track bed structure are automatically distinguished, forming a building information model that includes both the sleeper and the track bed structure.

[0048] This method does not view scanned data in isolation, but rather integrates and compares it with known, precise standard 3D models of railway sleepers. Then, by analyzing the spatial relationship between the coordinate-mapped point cloud data and the sleeper model, it can automatically determine which rebar points are located inside the sleeper entity and which are located below and around the sleeper. This clearly distinguishes the two structural entities of "sleeper" and "ballast," and identifies the dense rebar mesh within the ballast that requires special protection. Finally, it generates a BIM model with rich attribute information, including: ① the precise geometric entity of the sleeper; ② the boundary and volume of the ballast; ③ the precise 3D position, orientation, and embedment depth of each key rebar within the ballast.

[0049] The final BIM model allows construction workers to "see" the precise three-dimensional arrangement of the steel bars inside the track bed, fundamentally avoiding potential steel bar damage caused by blind drilling and splitting. This is the primary prerequisite and core guarantee for the subsequent "directional micro-damage" to be achieved. Furthermore, it provides the only reliable data input for the BIM platform to automatically generate splitting and drilling schemes that avoid the steel bars in subsequent steps, greatly reducing human error and improving the scientificity and reliability of the scheme.

[0050] Furthermore, the combination of multi-beam radar and optimized scanning path enables rapid and comprehensive data acquisition; algorithms such as Hough transform enable automated and efficient data processing, and the entire "reconnaissance" process can be completed quickly during the construction preparation stage, leaving valuable core window time for substantive replacement work, which meets the requirement that every second counts in subway night construction.

[0051] Furthermore, the method can deeply integrate non-destructive testing, image recognition, and building information modeling technologies, visualize hidden works, and digitize experience-based decision-making, thus providing a deterministic foundation for safe, efficient, and intelligent implementation.

[0052] Input sleeper damage data into the building information model to obtain a splitting borehole scheme;

[0053] The Building Information Model (BIM) includes n pre-defined categories for sleeper damage, such as D01 transverse through cracks, D02 corner chipping, and D03 mesh-like cracks. On-site personnel then manually input or upload the damage code and approximate location of the damage (e.g., the left end of the sleeper) as key parameters to the BIM platform based on the inspection results. The BIM platform's integrated rule inference engine then uses the damage code, sleeper thickness, and track bed reinforcement spacing as input variables. Finally, it automatically generates the relative coordinates, drilling depth, and drilling sequence of the split holes using pre-defined mapping rules. The generation of the relative coordinates is based on the damage code to determine the drilling layout strategy. For example, for D01 transverse through cracks, the system defaults to generating a ring-shaped drilling scheme around the sleeper, close to the track bed interface, to form an isolation joint; for D02 corner chipping, it may add locally reinforced holes around the damaged area.

[0054] Drilling depth The generation method is determined by the sleeper thickness. and the surface reinforcement of the track bed The burial depth determines the effectiveness of sleeper splitting, and rules are used to ensure both effective sleeper splitting and avoidance of reinforcing steel. The constraint ensuring effective sleeper splitting can be expressed as:

[0055]

[0056] In the formula, This is a process allowance designed to prevent drilling through the bottom of the sleeper and to retain a thin layer of concrete to control the final fracture surface.

[0057] Ensuring that the constraints of the reinforcing steel are avoided can be expressed as:

[0058]

[0059] This takes into account construction errors, rebar location detection errors, and the additional safety margin provided for the rebar;

[0060] The final drilling depth is a compromise value resulting from the combined effects of two constraints:

[0061]

[0062] In actual intelligent solution generation, the BIM platform will first retrieve the depth of the reinforcing steel at the coordinate location, and then determine whether an effective splitting depth can be achieved under the premise of meeting safety constraints. If the depth of the track bed reinforcing steel is too shallow, the system may adjust the drilling position or activate a special solution (such as using a shorter splitting head with a different angle). The priority is always to ensure the safety of the reinforcing steel.

[0063] The drilling sequence is generated by the system planning the optimal drilling and splitting sequence, which usually follows the principle of "from the outside to the inside and symmetrical" to control stress release and prevent disorderly crack propagation. For example, for drilling to form an annular isolation joint, the splitting sequence is planned as follows: first the holes on the long sides of the sleeper, then the holes on the short sides.

[0064] According to the splitting drilling scheme, splitting holes are drilled on the sleeper, a splitting head is inserted into the splitting hole and gradient pressure is applied to make the cracks extend directionally along the interface between the sleeper and the track bed, and finally an annular isolation joint is formed around the sleeper to separate it from the track bed.

[0065] Through mechanical guidance and process control, the destructive energy is precisely and predictably released at a pre-set interface to form an isolation joint, making the subsequent removal of broken sleepers easier. The construction waste (fragments) generated by this method are regular and small in size, making them easy to remove quickly. At the same time, since it causes almost no damage to the track bed, it saves a lot of procedures and time for repairing damaged track beds, greatly simplifying the entire replacement process.

[0066] To ensure the accurate formation of the isolation joint, the contact portion between the splitting head and the sleeper at the splitting hole is wedge-shaped. When the hydraulic cylinder drives the wedge-shaped part of the splitting head to open the splitting hole, it generates a huge radial expansion force. This force can be decomposed into two main components: a lateral tensile force and a vertical tensile force. The lateral tensile force is a force parallel to the horizontal plane of the sleeper and is an effective force for creating horizontal cracks and achieving "directional" expansion. The vertical tensile force is a force perpendicular to the horizontal plane and may cause the sleeper to tilt upwards or crush and damage the track bed below. It is a force that needs to be suppressed.

[0067] According to the principles of mechanics, both the lateral and vertical tensile cracking forces are related to the wedge angle. Therefore, when the wedge angle is 8°-13°, the lateral force can be much greater than the vertical force. Theoretically, more than 99% of the effective force is used to generate horizontal tensile cracks, thereby "forcing" the crack to preferentially extend along the path of least resistance—that is, the bonding interface between the sleeper and the track bed, thus achieving "directional" control of the crack. It should be noted that for small short sleepers (460×270×150mm), the wedge angle is set to 12°.

[0068] Furthermore, the gradient pressurization specifically includes three stages: the first stage is to slowly initiate cracking with pressure below the set pressure threshold; the second stage is to gradually increase the pressure to allow the crack to extend stably to the surface of the track bed; the third stage is to increase the pressure again to allow the crack to fully penetrate and form the isolation joint; that is, slow cracking (low pressure) → stable extension (medium pressure) → full penetration (high pressure). This gradient pressurization method is a proactive and refined control of the concrete fracture process.

[0069] The process involves three stages: First, a load is slowly applied at a pressure lower than the dynamic tensile strength of the concrete to induce microcracks around the borehole wall, preventing the concrete at the borehole opening from collapsing due to impact loads. Second, the pressure is gradually increased to allow the cracks to extend steadily forward from their initiation point. The pressure in this stage must be sufficient to overcome the resistance to crack propagation, ensuring that the cracks can continue to grow in a predetermined horizontal direction until they approach the surface of the track bed. Third, the pressure is further increased to eventually connect the expanded cracks into a continuous, annular, through-crack around the sleeper, i.e., a separation joint. The width of this crack is controlled at 2-4 mm, ensuring both separation effectiveness and facilitating subsequent removal.

[0070] Drill a grid of break holes on the isolated sleeper and split it to break it into multiple pieces. Remove the pieces to form a sleeper pit and then flatten the bottom surface of the sleeper pit.

[0071] This grid-based splitting method enables the fracturing process to be fast and orderly, and because all fracturing occurs strictly inside the sleeper that has been enclosed by the isolation joint, it will not cause new damage or cracks to the surrounding exposed ballast pit walls and bottom surfaces.

[0072] In addition, the grid-like distribution of the break holes is arranged in an m-row × n-column matrix, where m and n are both integers greater than or equal to 2. By splitting the sleeper sequentially, it is broken into more than m × n blocks, forming an artificially predetermined fracture path. The mechanical principle is that after each hole is inserted with a splitting head and pressurized, radial micro-cracks will be generated around it. When the expanding cracks of two adjacent holes meet inside the concrete, they will preferentially penetrate along the line connecting the two points, forming a relatively straight fracture surface. Through the planned grid-like hole positions, the cracks can be systematically guided, dividing the originally large sleeper into a series of small fragments of regular size and similar volume.

[0073] It should be noted that the slope of the bottom of the sleeper pit after chiseling should deviate from the design reference surface by ≤0.5°, and local protrusions should be ground until the flatness error is ≤2mm; after cleaning the slag, apply a silica interface agent.

[0074] A mortar layer is laid in the sleeper pit, a new sleeper is hoisted and precisely positioned, and then grouting is performed;

[0075] A zoned microwave emission array is used to intelligently temperature-controlled cure the newly poured mortar and grout.

[0076] Since temperature is a key factor affecting the hydration rate of cement, and the intelligent temperature control system stabilizes the curing temperature within the optimal range, allowing the material strength to increase rapidly in an exponential manner, this means that within the same overnight maintenance window, not only can sleeper replacement be completed, but the new structure can also have sufficient early strength to meet the requirements for timely and safe operation of the line the next morning. Furthermore, uniform and controlled temperature rise curing effectively reduces the generation of temperature stress cracks and shrinkage cracks, improves the density and durability of the mortar layer and grout, thereby extending the maintenance cycle and service life.

[0077] In addition, the mortar layer is made of sulfoaluminate cement + silica aerogel + early strength agent system and is set at about 3cm. The primary function of this mortar layer is not to completely bear the load, but to act as a flexible and plastic "interface transition layer". It can fill the micro-unevenness of the pit bottom, ensure 100% close contact of the bottom surface of the new sleeper, avoid stress concentration caused by local voids, and at the same time, its fluidity allows for minor posture adjustments in the early stage of sleeper placement.

[0078] During the hoisting of the new sleepers, the tilt sensor communicates with the building information model platform in real time. The platform compares the real-time posture with the design parameters and drives the hoisting equipment to adjust the angle until the horizontal error is less than the allowable value before the hoisting equipment can be placed in position.

[0079] After the sleepers are in place and preloaded to stabilize the bottom mortar, cement-based grout is injected into the gaps between the sides of the sleepers and the pit walls of the track bed. The injection process uses low-pressure (0.3-0.5MPa) precision grouting, and the BIM model monitors the grouting pressure in real time. The purpose is to ensure that the grout can fully fill all the gaps and achieve a "wrapping" effect. However, the pressure must be strictly controlled to prevent excessive pressure from lifting or pushing the precisely positioned sleepers.

[0080] Intelligent temperature control maintenance specifically involves using temperature sensors buried at different depths to provide real-time temperature feedback.

[0081] The control platform dynamically adjusts the power of the microwave transmitter in the corresponding area based on the temperature feedback, so that the temperature in the maintenance area is maintained within a constant preset range.

[0082] Because microwaves can penetrate the surface of concrete, their electromagnetic energy is directly absorbed by water molecules in the material and converted into heat energy. This achieves volume heating from the inside out, and the heating is more uniform, faster, and has high thermal efficiency. In addition, because the thickness, material, and heat dissipation conditions of different areas such as the mortar layer at the bottom of the sleeper, the side grouting joints, and the contact interface with the track bed are different, the zoned microwave emitting array allows for the application of differentiated energy input to different areas to achieve overall balanced heating.

[0083] Specifically, a 3×2 microwave transmitting array is used, with each transmitter having a power of 300W and a frequency of 915±15MHz. The array is arranged in zones corresponding to the bottom of the sleeper, the grouting joint, and the track bed interface to ensure that the microwave penetration depth reaches 10-12cm and that the energy evenly covers the maintenance area. Six temperature sensors are embedded at various points on the surface, bottom, and middle (top, bottom, left, and right) of the new sleeper.

[0084] Temperature sensors are embedded in the surface, bottom, and grouting joint of the new pillow to form a distributed temperature monitoring network. The temperature control module in the subsequent BIM model is preset with the optimal curing temperature curve. The platform collects the temperature of each point in the temperature monitoring network at a rate of seconds and dynamically calculates and adjusts the power of the microwave transmitter head of each corresponding zone through the built-in algorithm.

[0085] Specifically, the BIM platform has a built-in temperature controller with a sampling period of 1 second and a preset curing baseline temperature of 60℃. When the temperature at any monitoring point exceeds 65℃, the power of the microwave transmitter in the corresponding area is automatically reduced to 200W. When the temperature is below 55℃, the power is restored to 300W. The curing is performed in two stages: 0-10 minutes is the heating stage, and 10-30 minutes is the constant temperature stage.

[0086] Example 2

[0087] As one embodiment, for the step of forming annular isolation joint, an array of acoustic emission sensors is deployed on the sleepers to monitor the energy value of crack propagation in real time. When the energy value exceeds the threshold, the splitting equipment is controlled to perform pressure reduction or pressure stop operation.

[0088] When cracks initiate or propagate inside brittle materials such as concrete, transient elastic stress waves are generated due to the sudden release of strain energy. This phenomenon is called acoustic emission. Therefore, piezoelectric ceramic acoustic emission sensors installed at the four corners of the sleepers can convert these weak stress waves propagating inside the material into electrical signals. One of its core monitoring parameters is the energy value, which corresponds to the total energy released by the elastic waves and is directly related to the severity of crack propagation (velocity and length).

[0089] Furthermore, the threshold is not a fixed value, but is preset or dynamically calculated based on the safety splitting model in the BIM model. Under normal, stable expansion along a predetermined horizontal interface, the energy released by the crack is relatively gradual and predictable. This threshold represents a safety red line, corresponding to abnormally high energy events that may occur when the crack begins to expand unstablely, bifurcate, or encounter hard obstacles (such as accidentally touching steel bars). The BIM model receives energy data streams from various sensors at an extremely high frequency of 0.2 seconds and performs real-time comparison and analysis. This short cycle ensures the real-time nature of the control. Once the energy readings of any one or more sensors are detected to rise sharply in a short period of time and exceed the threshold, the BIM platform will immediately judge it as an "abnormal energy surge," meaning that the crack expansion behavior is out of control. Finally, after making the abnormal judgment, the BIM platform issues a pressure reduction or pressure stop command to the control system of the hydraulic splitting equipment in milliseconds.

[0090] This embodiment constitutes a closed-loop control system for the splitting step, which can capture anomalies that the scheme model fails to predict and intervene decisively before causing substantial structural damage, reducing the risk of "potential damage to the track bed" from probability to near zero, and achieving reliable protection against minimal damage; by accumulating a large amount of acoustic emission data from successful and corrective cases, the splitting model and pressure curve in BIM can be optimized in reverse.

[0091] Example 3

[0092] like Figure 2 The illustrated quick-change system for subway ballastless track sleepers using directional micro-damage splitting includes:

[0093] The data acquisition and processing module is used to scan the target sleeper and the underlying track bed, identify the location of the reinforcing bars, and construct a building information model that includes the sleeper and track bed structure.

[0094] The intelligent decision-making module is used to input sleeper damage data into the building information model to obtain a splitting drilling scheme;

[0095] The splitting execution module is used to drill splitting holes on the sleeper according to the splitting drilling scheme, insert a splitting head into the splitting hole and perform gradient pressure to make the crack extend directionally along the interface between the sleeper and the track bed, and finally form an annular isolation joint around the sleeper to separate it from the track bed.

[0096] And drill grid-distributed breaking holes on the isolated sleepers, split them to break them into multiple pieces and remove them to form sleeper pits, and then perform flattening treatment on the bottom surface of the sleeper pits.

[0097] The maintenance module is used to lay a mortar layer in the sleeper pit, hoist a new sleeper and position it precisely, and then perform grouting;

[0098] And a zoned microwave emission array is used to intelligently temperature-controlled cure the newly poured mortar and grout.

[0099] Example 4

[0100] As attached Figure 3 An electronic device shown includes:

[0101] Processor, memory, communication interface;

[0102] The memory is used to store the executable instructions of the processor;

[0103] The processor is configured to execute the aforementioned method for rapid replacement of subway ballastless track sleepers using directional micro-damage splitting by executing the executable instructions.

[0104] A readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the above-described method for rapid replacement of subway ballastless track sleepers using directional micro-damage splitting.

[0105] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for rapid replacement of subway ballastless track sleepers using directional micro-damage splitting, characterized in that, Specifically, it includes: The target sleeper and underlying track bed are scanned to identify the location of the reinforcing steel and a building information model including the sleeper and track bed structure is constructed. The specific process is as follows: A 1.5GHz center frequency multibeam ground-penetrating radar was used to perform a linear trajectory uniform speed scan on the target sleeper and its underlying track bed to generate a B-scan track bed profile image. The hyperbolic reflection characteristics of the reinforcing bars in the image are identified using the Hough transform algorithm. The embedment depth of the reinforcing bars is calculated and mapped to the BIM coordinate system. Combined with the built-in 3D sleeper model in BIM, the physical boundaries of the sleepers and the boundaries of the track bed structure are automatically distinguished, forming a building information model that includes both the sleepers and the track bed structure. Input sleeper damage data into the building information model to obtain a splitting borehole scheme; According to the splitting drilling scheme, splitting holes are drilled on the sleeper, a splitting head is inserted into the splitting hole and gradient pressure is applied to make the cracks extend directionally along the interface between the sleeper and the track bed, and finally an annular isolation joint is formed around the sleeper to separate it from the track bed. Among them, the contact part between the splitting head and the sleeper of the splitting hole is a wedge angle, and the wedge angle is 8°-13°; Drill a grid of break holes on the isolated sleeper and split it to break it into multiple pieces. Remove the pieces to form a sleeper pit and then flatten the bottom surface of the sleeper pit. A mortar layer is laid in the sleeper pit, a new sleeper is hoisted and precisely positioned, and then grouting is performed; A zoned microwave emission array is used to intelligently temperature-controlled cure the newly poured mortar and grout.

2. The method for rapid replacement of subway ballastless track sleepers using directional micro-damage splitting as described in claim 1, characterized in that: The scanning path adopts a serpentine trajectory, or a combination of longitudinal main scan and lateral rescan.

3. The method for rapid replacement of subway ballastless track sleepers using directional micro-damage splitting as described in claim 1, characterized in that: An array of acoustic emission sensors is installed on the sleeper to monitor the energy value of crack propagation in real time. When the energy value exceeds the threshold, the splitting device is controlled to perform pressure reduction or pressure stop operation.

4. The method for rapid replacement of subway ballastless track sleepers using directional micro-damage splitting as described in claim 1, characterized in that: The gradient pressurization specifically includes three stages: the first stage is to slowly initiate cracking with pressure below a set pressure threshold; the second stage is to gradually increase the pressure to allow the crack to extend stably to the surface of the track bed; and the third stage is to increase the pressure again to allow the crack to completely penetrate and form the isolation joint.

5. The method for rapid replacement of subway ballastless track sleepers using directional micro-damage splitting as described in claim 1, characterized in that: The grid-like distribution of the break holes is arranged in an m-row × n-column matrix, where m and n are both integers greater than or equal to 2. By splitting the sleeper sequentially, it is broken into more than m × n blocks.

6. The method for rapid replacement of subway ballastless track sleepers using directional micro-damage splitting as described in claim 1, characterized in that: The intelligent temperature control maintenance specifically involves: feeding back real-time temperature through temperature sensors buried at different depths; The control platform dynamically adjusts the power of the microwave transmitter in the corresponding area based on the temperature feedback, so that the temperature in the maintenance area is maintained within a constant preset range.

7. The method for rapid replacement of subway ballastless track sleepers using directional micro-damage splitting as described in claim 1, characterized in that: During the hoisting of new railway sleepers, the tilt sensor communicates with the building information model platform in real time. The platform compares the real-time posture with the design parameters and drives the hoisting equipment to adjust the angle until the horizontal error is less than the allowable value before the hoisting equipment can be placed in position.

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