Method and system for repairing a flexible support block off-joint void

Abstract

The present application relates to the rail transit ballastless track maintenance technical field, specifically discloses a kind of elastic supporting block off joint air lift repair method and system. Including: detecting positioning air lift disease, symmetrically inclined drilling to not damage structure on the two sides of supporting block;With not more than 5cm low height lifting rail and supporting block;Secondly punch through hole and completely clean interface;Inject special high fluidity, fast-setting high-strength grouting material;After resetting, it is compacted using cross-rail double-head high-frequency vibrator;Subsequently, linear fine adjustment and limiting are carried out;Finally, clean up the site and restore the line.The corresponding system integrates special equipment such as special rail, inclined drilling, high-pressure blowing and sucking cleaning, quantitative grouting and high-frequency vibration.The present application realizes efficient and radical repair of off joint air lift disease within skylight time through the synergistic process of "low rail lifting, inclined hole, pressure maintaining and grouting, and strong vibration" without the need for large-scale disassembly of fasteners and complete lifting of supporting blocks.

Description

Technical Field

[0001] This invention relates to a repair method and system, and more particularly to a repair method and system for repairing gaps and loose suspension of elastic support blocks. Background Technology

[0002] Elastic support block ballastless track has been widely used in railway tunnels and urban rail transit in my country due to its excellent vibration reduction performance and relatively convenient maintainability. However, under long-term train cyclic loads and environmental factors, gaps easily form between the elastic support blocks and the underlying concrete track bed, resulting in "empty" defects. These defects compromise the integrity and stability of the track structure, exacerbate wheel-rail dynamics, worsen track geometry, seriously affect train safety and stability, and significantly increase maintenance workload. Therefore, developing an efficient, reliable method and matching tooling for repairing gaps and empty ballast in elastic support blocks suitable for short railway maintenance windows is a key technical problem urgently needing to be solved in this field.

[0003] Currently, several technical solutions have been proposed and applied for the repair of gaps caused by the loosening of elastic support blocks:

[0004] 1. Shim Adjustment and Subsurface Filling Method: As described in the paper "Research on the Impact and Remediation of Unloaded Support Blocks in Elastic Support Block Ballastless Track," for Class II damage with a small amount of unload, shims are inserted under the rail for height adjustment. For Class III damage with a large amount of unload, the fasteners need to be loosened, the support blocks removed, and epoxy resin mortar or other repair materials injected into the excavated track bed area for filling. Although this method can address the issue, it generally suffers from complex construction processes, requiring complete loosening of fasteners and lifting of support blocks, resulting in a large amount of on-site work and a long operation time. Furthermore, the shim method can only temporarily alleviate the damage and cannot fundamentally fill the unloaded gaps.

[0005] 2. Small-Angle Oblique Grouting Method: As described in the paper "Repair Technology for Track Support Block Defects in Subway Lines," this method involves drilling holes at a small angle (15° to 20°) at a certain distance from the joint and then grouting. Although this method attempts to fill the joint with grout, the drilling angle design may lead to inaccurate control of the grouting path. Furthermore, the repair process does not reposition the suspended elastic support block, making it impossible to guarantee the filling state and density of the grouting material in the joint. Therefore, the long-term reliability of the repaired structure is questionable.

[0006] 3. Vertical drilling and grouting method: As shown in the invention patent "Sleeper detachment and empty-suspension repair structure and repair method for ballastless track CN109736151A", this method proposes to drill and grout vertically at the contact surface between the support block and the track slab. However, due to the protruding structures on the upper edge of the elastic support block and the flange of the track shoe, it is difficult to implement vertical drilling in terms of physical space, and it is very easy to damage the track shoe body. The technical solution has low feasibility and is difficult to apply to actual on-site repair operations.

[0007] In summary, the existing technology has the following main drawbacks:

[0008] (1) The repair process is complex and the work efficiency is low: most methods require completely loosening the fasteners and raising the support blocks significantly or completely. The preparation work is extensive and seriously occupies the limited "skylight" operation time, which cannot meet the needs of railway rapid maintenance.

[0009] (2) The repair effect is unreliable or non-radical: or only temporary adjustments are made (such as padding), or the grouting process is not combined with the repositioning of the support block, resulting in the gaps of the empty hanging can not be effectively and densely filled, and the disease is prone to recurrence.

[0010] (3) The technical solution does not match the actual site conditions: Some solutions (such as vertical drilling) are difficult to implement due to the structural characteristics of the elastic support block itself, and may even cause secondary damage to the original healthy components.

[0011] (4) Lack of systematic process and special tooling: Existing methods focus on single repair steps and have not formed a set of efficient and low-interference repair systems that integrate positioning, hole opening, cleaning, grouting, resetting, vibration and fine adjustment. Summary of the Invention

[0012] To address the shortcomings of existing technologies, this invention aims to provide a novel method and supporting tooling for repairing gaps in elastic support blocks during unsupported operation. The core of this method lies in the innovative use of a process combining "low rail lifting height with symmetrical oblique drilling and grouting pressure-maintaining grouting." This minimizes the loosening range of fasteners and avoids completely lifting the support block, achieving effective and dense filling of the gaps during unsupported operation. This significantly improves work efficiency during the "maintenance window" period while ensuring the fundamental repair effect, and minimizes damage to the existing track structure during the repair process. The technical solution is as follows:

[0013] A method for repairing gaps and unsupported suspension of elastic support blocks, characterized by performing the following steps sequentially within a skylight window:

[0014] (1) Preparation and positioning: Conduct locking rail temperature test and initial rail data acquisition; determine the repair range, location and amount of looseness of the elastic support block where dynamic slack occurs;

[0015] (2) Preliminary drilling: At least one grouting hole is drilled obliquely on both sides of the elastic support block. The drilling depth is such that it does not penetrate the groove of the elastic support block and does not damage its rubber boot.

[0016] (3) Lifting preparation: Determine the height to which the elastic support block needs to be lifted and the range of fasteners to be loosened according to the repair requirements;

[0017] (4) Fastener loosening and rail lifting: Loosen the fasteners on both sides of the elastic support block within the specified range determined in step (3); use a rail lifting device to lift the rail together with the elastic support block and its boot as a whole module to a limited height, which is limited to a height sufficient for subsequent grouting operations but significantly less than the height required to fully lift the support block;

[0018] (5) Secondary drilling and cleaning: Continue drilling along the initial drilling direction to make the hole pass through the groove wall; use a high-pressure dust blowing device and a dust suction device alternately to clean the dust, moisture and impurities in the groove;

[0019] (6) Grouting and filling: Grouting material is injected into the groove through at least one of the grouting holes using a grouting device. The grouting volume is recorded and compared with the empty hanging volume determined in step (1) to achieve filling quality control with quantitative data as feedback.

[0020] (7) Reset, vibration and initial compaction: Lower the rail to position the elastic support block together with the boot; use a double-headed high-frequency vibrator that can cross the rail to vibrate the elastic support block, so that the grouting material can be compacted and filled in the empty area and the uncompacted part of the track bed under the action of falling pressure and vibration.

[0021] (8) Fine adjustment and limiting: While the grouting material is in a fluid state, measure the track alignment and make fine adjustments; use tie rods and pads to limit the elastic support blocks; fill the gaps between the top of the boot and the track bed with grout;

[0022] (9) Cleaning and restoration: When the grouting material loses its fluidity, remove the grouting device and clean it; after the grouting material hardens, remove the limiting fixture, seal the grouting hole, and restore the line.

[0023] This invention also discloses a system for repairing gaps in elastic support blocks using the above-described method, characterized by comprising: a specially designed rail lifting device for raising the rail, along with the elastic support block and the boot, to a limited height; an oblique drilling device for drilling grouting holes at a specified angle on the elastic support block; a cleaning device including a high-pressure dust blower and a vacuum cleaner for alternately cleaning the grooves and holes; a special grouting device for injecting grouting material through the grouting holes, measuring the grouting volume in real time, and having a pressure maintenance function to maintain the pressure within the grouting system after grouting and before vibration; a cross-rail dual-head high-frequency vibrator for compacting the positioned elastic support block; and a limiting fixture including a tie rod and a pad for fixing the position of the elastic support block during the fine-tuning stage.

[0024] Beneficial effects

[0025] 1. Significantly improves repair efficiency and meets the requirements of skylight operation.

[0026] By employing a "low rail lifting height" (generally not exceeding 5cm) combined with a limited fastener loosening range (generally not exceeding 10m), this invention completely changes the traditional operation mode that requires fully lifting the support block and extensively disassembling the fasteners. This significantly reduces on-site preparation work and auxiliary operation time, enabling the entire repair process to be efficiently completed within the railway's limited 3-4 hour "maintenance window," solving the industry problem of not being able to perform thorough repairs within the maintenance window and greatly improving the utilization rate of the maintenance window.

[0027] 2. Achieve fundamental repair and ensure long-term reliability.

[0028] A combined process of "oblique drilling and grouting pressure-maintaining grouting" was adopted. First, symmetrical oblique drilling (angle 30°-45°) with controlled depth established precise channels for grouting, avoiding damage to the support block structure. Second, after slightly lifting and repositioning the support block, a specially formulated high-performance grouting material was injected, and immediately compacted using a cross-track dual-head high-frequency vibrator. This combined technology ensures that the grouting material, under the dual action of pressure and vibration, fully and densely fills even the smallest gaps (up to 0.05mm) and areas of loose track bed, achieving three-dimensional and full filling of these gaps. This fundamentally eliminates the risk of recurrence and ensures a long-lasting and reliable repair effect.

[0029] 3. Protect the existing structure to the greatest extent possible and reduce the risk of damage during maintenance.

[0030] The entire repair process was carried out without completely removing the elastic support block from its original position. The "low-lift" operation and precise control of drilling depth and angle effectively avoided secondary damage to the elastic support block itself, the rubber boot, and the surrounding track bed structure. Compared to existing technologies that might involve widening the track bed or vertical drilling, this invention minimizes interference and damage to the original healthy structure, protecting the overall integrity of the track structure.

[0031] 4. The grouting material has excellent performance, ensuring the quality of repair.

[0032] The specialized grouting material used features low initial viscosity (≤100 mPa·s), good fluidity retention (≤200 mPa·s within 30 min), early and high strength (≥1 MPa at 1 h, ≥10 MPa at 7 d), and strong adhesion (≥1.5 MPa). Its optimized composition (such as polymer and ultrafine rapid-hardening cement composite system) ensures that the material can be smoothly injected into tiny gaps and quickly set and harden to form a high-strength integral with the concrete track bed, effectively resisting the cyclic load of trains and ensuring the mechanical properties and long-term durability of the repaired area.

[0033] 5. High repair accuracy, facilitating track condition restoration.

[0034] During the window period (≤30 minutes) when the grouting material is still fluid, the track alignment is simultaneously measured and fine-tuned, and fixed using limiting fixtures such as tie rods and pads. This technique can promptly correct track geometric deviations that may be caused by the repair work, and can accurately replenish grout in areas where the filling is incomplete, thereby ensuring that the track alignment after repair quickly returns to operational standards, guaranteeing the safety and stability of train operation.

[0035] 6. The specialized and efficient tooling system enhances construction quality and safety.

[0036] The supporting specialized tooling system (such as a specially designed rail lifting device, a cross-rail dual-head high-frequency vibrator, and a special grouting device) has been optimized for each step of this repair method. This system not only improves the operational efficiency and mechanization of each stage, reducing the uncertainty of manual operation, but its targeted design (such as cross-rail capability and dual-head vibrator) also enhances the adaptability and safety of construction during track maintenance windows and in narrow track environments, ensuring the standardized execution of the repair process. Attached Figure Description

[0037] Figure 1 Schematic diagram of the low-rail single-hole injection grouting construction process

[0038] Figure 2 Schematic diagram of oblique holes on both sides of the support block

[0039] Figure 3Schematic diagram of lifting and adjusting the elastic support block

[0040] Figure 4 Grouting Repair Diagram

[0041] Figure 5 Schematic diagram of a cross-track dual-head high-frequency vibrator

[0042] Attached Figure Descriptions and Corresponding Numbers

[0043] 1-Rail; 2-Fasteners; 3-Elastic support blocks; 4-Slab bed; 5-Hanging or gap; 6-Grouting holes; 7-Grouting repair material; 8-High-frequency vibrator. Detailed Implementation

[0044] The following detailed description of the elastic support block gap repair method and its tooling system according to the present invention, with reference to specific embodiments, is provided below.

[0045] Example 1: Specific Implementation of the Repair Method

[0046] For a section of elastically supported block ballastless track in a tunnel exhibiting dynamic slack-out defects, the following steps are used for repair:

[0047] Step (1) Preparation and Positioning

[0048] First, the "locked rail temperature test" is crucial. Due to the thermal expansion and contraction of rails, changes in rail temperature cause regular changes in the track geometry. Measuring and recording the locked rail temperature under the current environment before repair work begins is essential to obtain a stable geometric baseline, avoiding measurement errors caused by temperature fluctuations and ensuring that the subsequent measurements of "empty load" reflect actual structural defects rather than temporary temperature-induced changes. Second, "determining the repair range and empty load of the dynamically detached elastic support block" is a precise diagnostic process. This relies on high-precision testing equipment such as track inspection instruments. By detecting and analyzing the dynamic response of the track structure when a train passes (such as vertical displacement and acceleration), the support block that has abnormally detached under live load is accurately located. Simultaneously, using feeler gauges, specialized thickness gauges, or laser rangefinders, the static gap (i.e., empty load) between the bottom surface of the support block and the top surface of the concrete track bed is quantitatively measured. This quantitative data serves as the initial input and calculation basis for all subsequent operations (such as lifting height and grouting volume). Failure to perform this step or inaccurate execution will result in unclear repair objectives and incorrect material estimation, potentially leading to "untreated" or "over-treated" conditions, wasting window time and materials.

[0049] Step (2) Preliminary drilling

[0050] Regarding the drilling angle (30° to 45°): This angle range is the result of comprehensive optimization considering the elastic support block structure (upper edge and outer flange of the boot), track bed space constraints, and grouting fluid dynamics. When the angle is less than 30°, the drilling path is too long, the drill rod is prone to swaying, accuracy is difficult to control, and the grout flow resistance increases significantly in the long-distance, small-angle inclined pipe, which is not conducive to filling. When the angle is greater than 45°, due to the protrusion of the upper structure of the support block and the obstruction of the boot flange, the drilling point will be too close to the top edge of the support block, or even impossible to drill, or even if drilling is possible, its path will be difficult to effectively cover the center of the suspended area. An angle of 30° to 45° precisely avoids interference from the upper structure, allowing for the shortest straight-line distance to penetrate obliquely to the side of the bottom groove of the support block, forming an ideal grouting channel with moderate resistance, pointing towards the core area of ​​the suspended area.

[0051] Regarding the number of holes (at least one hole, preferably symmetrical): The requirement of "at least one hole" is the minimum to ensure the possibility of injection. This is because an empty cavity may be irregular, and grouting from a single hole on one side can easily lead to unidirectional flow of grout within the cavity, potentially leaving filling dead zones or air pockets. Symmetrical oblique drilling on both sides of the support block aims to create two symmetrical grouting / venting channels. During grouting, simultaneous bidirectional grouting can be achieved, or a "grouting from one hole while venting and observing from the other" approach can be used. This symmetrical channel design is crucial for overcoming the irregularity of the empty cavity; it ensures that the highly fluid grout diffuses evenly within the cavity, effectively removing air and avoiding the formation of sealed air pockets or filling dead zones. It is an indispensable technical means to achieve three-dimensional full and dense filling of the empty area. If only one side or asymmetrical drilling is performed, it is very easy for the grout to flow unidirectionally, leaving unfilled areas and seriously affecting the repair quality.

[0052] Regarding drilling depth (without penetrating the groove or damaging the rubber): This is the core requirement of protective construction. The "groove" is the key structural surface connecting the bottom of the support block to the track bed, and it is also the fitting area for the rubber boot. Penetrating the groove will directly damage the load-bearing structure of the support block, significantly weakening its mechanical properties. The "rubber" boot is a core component providing elasticity and vibration isolation; damage to it will lead to vibration damping failure and accelerated corrosion due to moisture intrusion. Therefore, the goal of depth control is to ensure that the drill tip just reaches the outer edge of the groove sidewall or penetrates slightly into the wall thickness, preparing for subsequent "secondary drilling" to penetrate the wall thickness, but never reaching deep into the groove's internal space or touching the rubber. To ensure this depth, a special drilling tool with a depth gauge or limiter must be used, and the operator must be familiar with the specific dimensions of the support block. If the depth is not controlled and drilling is done arbitrarily, irreversible structural damage will be caused, repairing one defect while creating another, completely violating the "low-damage" principle of this method.

[0053] Step (3) Lifting Preparation

[0054] The decision to "generally raise the height by no more than 5cm" is based on several considerations: First, this height is sufficient to create a construction space between the support block and the track bed that allows for grout pipe insertion, grout flow, and initial observation, typically meeting the repair needs of most open-span joints. Second, raising the rail by more than 5cm will significantly increase the internal stress of the rail and connected components, adversely affecting the fastening system and adjacent track structures, and requiring the loosening of a larger area of ​​fasteners to release rail stress, resulting in a non-linear increase in safety risks and workload. Third, from an operational efficiency perspective, a low raise significantly reduces the time available for raising and resetting. Similarly, the "fastener loosening distance generally not exceeding 10m" is also an optimized engineering experience value. It ensures that sufficient rail length is released on both sides of the raising point to safely accommodate the longitudinal displacement and stress generated by the raising, while strictly limiting the workload of loosening and re-tightening fasteners to a range that can be efficiently completed within the track maintenance window. Without this quantitative preparation, arbitrarily determining the lifting height and range based on experience can easily lead to insufficient lifting (insufficient space, difficult repair operations) or excessive lifting (drastically increased workload, high safety risks), failing to achieve the core objective of "fast and low interference".

[0055] Step (4) Unfastening fasteners and lifting rail components

[0056] This step is the key action in physically creating space for repair. "Using a specially designed rail lifting device" is crucial. This device differs from ordinary jacks or large track lifting machines, and its design must meet the following requirements: ① Sufficient and stable lifting force; ② Precise stroke, capable of millimeter-level adjustment, ensuring that the lifting height strictly conforms to the planned value in step (3); ③ Reasonable design of support points and contact surfaces to avoid damage to the bottom edge or web of the rail; ④ Compact size, facilitating rapid deployment and operation in narrow spaces beside tunnels or tracks. "Lifting the rail together with the elastic support block and rubber boot" is the core action. This means that during the lifting process, the relative position between the support block and the rubber boot, as well as the fastening connection with the rail (even though the fastening nuts have been loosened), remain unchanged, and the rail is lifted as a "whole module". This minimizes the relative displacement and disturbance of internal components, protects the existing state of the fastening system and rubber boot, and lays the foundation for subsequent precise repositioning. If the support block is lifted up separately or forcibly peeled off, the engagement between the fastener and the support block will be damaged, and the shoe will be easily misaligned or damaged, greatly increasing the difficulty and uncertainty of resetting.

[0057] Step (5) Secondary drilling and cleaning

[0058] The "secondary drilling" performed after the support block is lifted is to completely penetrate the concrete sidewall of the support block's groove with a drill bit, based on the preliminary hole already formed, thereby opening the final physical barrier for grout to enter the suspended area. This operation must be performed after lifting, because if it is drilled before lifting, the borehole may be blocked by debris, and the borehole wall may be damaged due to stress changes during lifting. The subsequent "alternating cleaning with high-pressure blowing and vacuuming devices" is a decisive process that determines the bonding strength of the repair interface. Its working principle is: high-pressure airflow (blowing) first impacts and peels off dust, moisture film, and loose particles adhering to the concrete surface with kinetic energy; then, negative pressure vacuuming efficiently removes the pollutants that are already in a suspended state. This "kinetic energy peeling + negative pressure recovery" cycle mode is a qualitative improvement over blowing or suction alone. It can solve the problem that traditional methods are difficult to remove adsorbed water vapor and micro-dust at the interface, creating near-ideal interface conditions for direct, high-strength chemical bonding and mechanical interlocking between the subsequent grouting material and the old concrete. Without such thorough cleaning, the interface contaminants will become a "barrier film," severely weakening the adhesion and causing the grouting material to detach from the substrate. The repair will then quickly fail under train dynamic loads, rendering the entire repair project meaningless.

[0059] Step (6) Grouting and filling

[0060] The special feature of "using a special grouting device" is that it must be able to stably pump the high-flowability, fast-setting grout required by this invention, and have the function of "recording the grouting volume". Recording the grouting volume and comparing it with the empty volume (which can be converted into theoretical volume) evaluated in step (1) in real time is the core link of quality control. When the actual grouting volume is close to the theoretical empty volume, and the grouting pressure is stable and there is uniform grout flow from the observation hole, it can be judged that the empty area has been fully filled. This closed-loop feedback mechanism avoids insufficient grouting (leaving cavities) or excessive grouting (generating unnecessary internal stress or even waste). The performance parameters of the grouting materials used all serve the stringent requirements of skylight repair: "initial viscosity not exceeding 100 mPa·s, viscosity not exceeding 200 mPa·s within 30 minutes" ensures that the grout has excellent fluidity when injected, can fill micro-cracks of 0.05 mm, and remains pumpable and adjustable during the working window period. The requirement of "1-hour strength exceeding 1 MPa" provides sufficient early load-bearing capacity, enabling the track to quickly withstand train loads after the track maintenance window ends. "7-day strength exceeding 10 MPa, with a bond strength not less than 1.5 MPa" ensures the long-term durability of the repair and its integrity with the old concrete. Its component design (polymer / cement composite system) is key to achieving these seemingly contradictory properties (high fluidity, rapid hardening, high strength, and high adhesion). Without this specialized material, ordinary cement mortar is difficult to inject into micro-cracks and sets slowly; ordinary chemical grouting materials may lack sufficient strength or adhesion, or be too expensive. Without grout volume measurement and comparison, construction quality relies entirely on worker experience, and reliability cannot be guaranteed.

[0061] After the predetermined grouting volume is reached and full filling is confirmed, the grouting pump is paused, but the grouting pipeline is kept sealed to maintain a low internal pressure (e.g., 0.05-0.1 MPa) in the system before the grout initially sets. This 'pressure-holding' state helps resist backflow or segregation of the grout that may occur due to gravity or minor disturbances, ensuring that the grout continues to fill the opened voids before re-vibration. It is one of the key aspects of the 'pressure-holding grouting method'.

[0062] Step (7) Repositioning, Vibration and Initial Compaction

[0063] A cross-track dual-head high-frequency vibrator is an essential tool for this step. Its "cross-track" design allows for flexible positioning without encroaching on limited track space. "Dual-head high-frequency" means it can simultaneously apply high-frequency micro-amplitude vibration to two key areas of the support block, resulting in high efficiency and uniform application. Its working principle utilizes high-frequency vibration energy (typically >100Hz) to transfer to the grout, causing a significant and instantaneous reduction in the friction and cohesion between particles within the grout (i.e., the "thixotropic" effect), and a sharp increase in apparent fluidity. Under the combined action of the pressure generated by the support block's own weight and the high-frequency vibration, the grout is powerfully driven, fully penetrating every corner of the unloaded area and effectively eliminating air bubbles, achieving thorough compaction. Without vibration, relying solely on the grout's own weight and natural flow can easily leave voids, air bubbles, or poorly compacted areas. These defects become stress concentration points and the source of future damage, severely affecting the long-term strength and service life of the restoration.

[0064] Step (8) Fine-tuning and limiting

[0065] "Measuring the alignment within the timeframe during which the grouting material maintains good fluidity (generally no more than 30 minutes)" is a time-sensitive requirement. At this stage, the grout has not yet hardened, and the position of the support blocks can still be adjusted with minor external force. Utilizing this window, track geometry measurement equipment can be quickly used to detect gauge, level, elevation, and alignment, and fine-tuning can be performed based on the results, eliminating any track geometry deviations caused by repair work at their inception. "Using tie rods, pads, etc., to limit and maintain the predetermined position of the support blocks" is a proactive "deformation prevention" measure. During the grout's solidification and hardening process, its strength increases from zero, and it is a vulnerable period before reaching sufficient strength to resist external forces. Tie rods provide horizontal constraints to prevent lateral displacement; pads provide vertical support to prevent settlement. Together, they form an external stability framework, ensuring that the track geometry is "frozen" in the optimal position after fine-tuning during the critical stage of material strength development. "Adding grout to areas where the support block boot is not fully saturated with grout" ensures sealing, preventing this area from becoming a channel for water or impurities to enter. If fine-tuning is not performed, the line quality may not meet the standards; if limiters are not used, even minor accidental disturbances during the slurry solidification period may cause the support block to shift, rendering the fine-tuning results useless.

[0066] Step (9) Cleaning and Restoration

[0067] "Removing the grouting device and cleaning it thoroughly once the grouting material loses its fluidity" is to prevent the grout from hardening inside the pipes and equipment, causing equipment damage and waste, and also to prepare for future use. "Removing the limiting fixture after the grouting material has hardened" ensures the material has sufficient strength to independently bear the load and maintain its position. "Sealing the grouting port" restores the integrity of the track bed surface and prevents the grouting hole from becoming an entry point for water and dirt, affecting aesthetics and durability. Finally, "restoring the line" includes checking that all fasteners have been re-tightened to the standard torque, cleaning all tools and materials on site, and ensuring the line is ready for operation. This is a complete closed-loop operation; none of the steps can be omitted. Hasty completion may leave safety hazards or affect the long-term effectiveness of the repair.

[0068] Through the detailed implementation of the above nine interconnected and progressively advanced steps, this invention forms a complete, rigorous, and highly operable technical solution, fully explaining "why to do it," "how to do it," and "the consequences of not doing it" for each step, thus systematically demonstrating its significant progress and high level of creativity compared to existing technologies.

[0069] Example 2: Specific Composition and Coordination of the Repair Tooling System

[0070] To efficiently implement the method described in Example 1, the system of the present invention consists of the following dedicated modules, which work together:

[0071] 1. Specially designed rail lifting device

[0072] This device is the core equipment for implementing the "low-lift rail" process. Its function is to smoothly lift the rail, elastic support blocks, and rubber boots as a whole with a controllable and limited stroke (typically designed so that the maximum lifting force and stroke do not exceed 5cm). It is usually based on a hydraulic or mechanical lifting mechanism and equipped with a precise stroke scale or displacement sensor. Unlike traditional large track lifting machines, this device is lightweight and adaptable to narrow spaces such as tunnels. The shape of its lifting head and the force application point are specially designed to ensure that the force is evenly applied to the bottom of the rail, avoiding local stress concentration that could damage the track components. If this special device is not used, and conventional jacks or large track lifting equipment are used instead, it is difficult to accurately control the small lifting amount, which can easily lead to excessive lifting (requiring more fasteners to be loosened) or unstable operation, thus failing to achieve the "low-interference" operation prerequisite and potentially causing accidental damage to the track components due to improper force application.

[0073] 2. Angled drilling equipment

[0074] This equipment is used to precisely drill grouting holes at an angle of 30° to 45° to the top surface of the track bed on the side of elastic support blocks. It integrates angle positioning and depth control mechanisms. The equipment is typically equipped with an angle gauge or a preset angle clamp to ensure the drill bit enters at a precise angle; it also features a depth limiter or sensor that automatically stops or alarms when the drill tip is about to touch the bottom of the support block groove or rubber boot, ensuring the process requirement of "drilling without penetrating the groove or damaging the rubber." Its drive unit can use an electric hammer or a light hydraulic drill to adapt to rapid operation within the maintenance window. Without this specialized equipment with precise angle and depth control, relying solely on manual hand-held drilling makes it extremely difficult to guarantee the uniformity of the drilling angle and the accuracy of the depth. Angle deviations may result in the grouting path failing to effectively cover the suspended area, while uncontrolled depth may directly drill through the groove or damage the boot, completely violating the core principle of this method of "establishing a channel without damaging the structure," leading to repair failure or secondary damage.

[0075] 3. Cleaning equipment (high-pressure dust blowing equipment and vacuuming equipment)

[0076] This device is a multi-functional unit tasked with thoroughly removing all contaminants from the grooves and suspended interfaces. A high-pressure blower generates a high-speed, clean airflow, forcefully blowing out loose dust and moisture from the crevices through nozzles inserted into the grouting holes, loosening and peeling off the attached materials. A vacuum cleaner follows closely behind, using negative pressure to powerfully extract and collect the blown-up fine particles, dust, and moisture. The principle behind this alternating cycle is that blowing first and then vacuuming overcomes the limitations of vacuuming alone in removing tightly attached impurities, while vacuuming first and then blowing cannot effectively handle settled particles. This "blow-suction" cycle ensures the interface meets the "engineering cleanliness" standard. Without this powerful alternating cleaning method, and only simple sweeping, residual dust and moisture at the interface would form a barrier between the grouting material and the old concrete, severely weakening the chemical bond and mechanical interlocking between them. This would cause the repair to detach from the interface and fail under train dynamic loads, even after the injection of high-performance materials, rendering the entire repair operation a failure.

[0077] 4. Special grouting device

[0078] This device is key to achieving "precise grouting and pressure maintenance," and it is not an ordinary grouting machine. Its special features are: First, it possesses precise metering capabilities, with a built-in flow meter or weight sensor that can display and record the injected grout volume or mass in real time, allowing for comparison with the empty grout volume and enabling scientific control of the filling amount. Second, the pumping pressure is adjustable and stable, enabling continuous pumping of highly fluid grout at an appropriate pressure (ensuring sufficient filling of tiny gaps while avoiding excessive pressure that could widen gaps or damage the structure). Third, the grout outlet is typically designed for quick connection to the grouting pipe, facilitating operation in confined spaces. Without this specialized device with metering and controllable pressure, the grouting volume would be estimated based solely on experience, easily leading to insufficient grouting (leaving voids) or excessive grouting (wasting grout or even generating undue expansion stress). Furthermore, ordinary grouting equipment struggles to stably pump the low-viscosity, fast-setting, high-performance grout required by this invention, potentially causing pipe blockage or pressure fluctuations, failing to achieve a full and dense filling effect.

[0079] 5. Cross-track dual-head high-frequency vibrator

[0080] This equipment is a specialized tool designed to ensure that the grouting material achieves "dense and full filling" in the initial stage. "Able to straddle rails" refers to its structural design, which allows it to operate straddling single or double rails or to move flexibly in narrow spaces beside the rails, adapting to the specific environment of railway lines. "Dual-head high-frequency" is its core working characteristic: two vibrating heads can simultaneously act on both sides of an elastic support block or two adjacent support blocks, with a high vibration frequency (usually greater than 100Hz), which can transfer high-frequency mechanical energy to the support block and the grout below in a short time. Its working principle is that the high-frequency, micro-amplitude vibration effectively reduces the apparent viscosity of the grout, instantly increasing its fluidity. This, combined with gravity and the pressure of the falling support block, further drives the grout to penetrate into every corner and micropore, and promotes the expulsion of internal air bubbles. If relying solely on the grout's own weight and natural flow, such high density cannot be achieved; air bubbles and voids will remain in the grout, forming weak areas. Using a common single-head vibrator is inefficient and difficult to operate conveniently in a track environment.

[0081] 6. Limiting fixtures (pull rod and pad)

[0082] This is a mechanical constraint system used to fix the spatial position of elastic support blocks before the grout solidifies. The tie rods are typically adjustable-length rigid rods with hooks or clamps at both ends, which can hook or clamp adjacent support blocks or fix them to the track bed. Horizontal constraint force is applied by adjusting the tie rod length to prevent lateral displacement of the support blocks. The pads are made of high-strength, wear-resistant material, and their shape and size are suitable for insertion into specific positions between the bottom of the support block and the track bed, providing vertical support and restraint. They are installed quickly after the fine-tuning process. Their working principle is to provide a stable "external skeleton" for the repair system, which is still in a fluid state, resisting minor displacements that may be caused by various accidental disturbances (such as personnel movement or equipment contact), ensuring that the track geometry remains in the ideal state after fine-tuning during the hardening process of the grout material. If this fast and reliable active restraint method is not used, and the position is maintained solely by the solidification of the grout itself, the support blocks are prone to accidental displacement in the early stages of grout strength growth, leading to the loss of fine-tuning results and deterioration of the track geometry.

[0083] In summary, each module of this system is specifically designed to address the particular technical challenges and efficiency bottlenecks in the methodology. The modules are closely integrated, and the collaborative workflow is smooth. This system and methodology form an inseparable organic whole, jointly achieving the goal of efficiently, with minimal interference, and fundamentally repairing the gaps and looseness of elastic support blocks within the designated "window" of operation, fully demonstrating the high level of innovation in system integration.

[0084] This invention, through the synergy of a "low-interference, precise, and systematic" repair method and a dedicated system, successfully solves the core contradictions of "low efficiency, poor results, significant damage, and difficulty in adapting to skylights" in the repair of gaps in elastic support blocks under suspended conditions. It provides a safe, reliable, efficient, and economical standardized repair solution with outstanding practicality and significant promotional value.

Claims

1. A method for repairing gaps and loose suspension of elastic support blocks, characterized in that, During the skylight window, it performs the following steps in sequence: (1) Preparation and positioning: Conduct locking rail temperature test and initial rail data acquisition; determine the repair range, location and amount of looseness of the elastic support block where dynamic slack occurs; (2) Preliminary drilling: At least one grouting hole is drilled obliquely on both sides of the elastic support block. The drilling depth is such that it does not penetrate the groove of the elastic support block and does not damage its rubber boot. (3) Lifting preparation: Determine the height to which the elastic support block needs to be lifted and the range of fasteners to be loosened according to the repair requirements; (4) Fastener loosening and rail lifting: Loosen the fasteners on both sides of the elastic support block within the specified range determined in step (3); use a rail lifting device to lift the rail together with the elastic support block and its boot as a whole module to a limited height, which is limited to a height sufficient for subsequent grouting operations but significantly less than the height required to fully lift the support block; (5) Secondary drilling and cleaning: Continue drilling along the initial drilling direction to make the hole pass through the groove wall; use a high-pressure dust blowing device and a dust suction device alternately to clean the dust, moisture and impurities in the groove; (6) Grouting and filling: Grouting material is injected into the groove through at least one of the grouting holes using a grouting device. The grouting volume is recorded and compared with the empty hanging volume determined in step (1) to achieve filling quality control with quantitative data as feedback. (7) Reset, vibration and initial compaction: Lower the rail to position the elastic support block together with the boot; use a double-headed high-frequency vibrator that can cross the rail to vibrate the elastic support block, so that the grouting material can be compacted and filled in the empty area and the uncompacted part of the track bed under the action of falling pressure and vibration. (8) Fine adjustment and limiting: While the grouting material is in a fluid state, measure the track alignment and make fine adjustments; use tie rods and pads to limit the elastic support blocks; fill the gaps between the top of the boot and the track bed with grout; (9) Cleaning and restoration: When the grouting material loses its fluidity, remove the grouting device and clean it; after the grouting material hardens, remove the limiting fixture, seal the grouting hole, and restore the line.

2. The method for repairing gaps and loose suspension of elastic support blocks according to claim 1, characterized in that: In step (3), the lifting height shall not exceed 5cm; the length of the fasteners to be loosened shall not exceed 10m.

3. The method for repairing gaps and loose suspension of elastic support blocks according to claim 1, characterized in that: In step (2), the angle of the angled drilling is 30° to 45°.

4. The method for repairing gaps and loose suspension of elastic support blocks according to claim 1, characterized in that: In step (6), the grouting material is a polymer composite material that has the ability to fill gaps with a width of 0.05 mm or more. Its initial viscosity does not exceed 100 mPa·s, its viscosity within 30 minutes does not exceed 200 mPa·s, its compressive strength after 1 hour is not less than 1 MPa, its compressive strength after 7 days is not less than 10 MPa, and its bond strength with concrete is not less than 1.5 MPa.

5. The method for repairing gaps and loose suspension of elastic support blocks according to claim 4, characterized in that: The grouting material comprises the following components by weight percentage: One or more of polymer emulsions, epoxy resins, polyurethanes, and asphalt powders, ranging from 1% to 70%; Ultrafine rapid-hardening cement, 30%–95%; Water, 0%–10%; Water-reducing agent, 0%–2%; Defoamer, 0%–0.5%; Thickener, 0%–0.5%; Wood fiber, 0%–1%.

6. The method for repairing gaps and loose suspension of elastic support blocks according to claim 1, characterized in that: In step (8), the grouting material maintains good fluidity for no more than 30 minutes, and the linearity measurement and fine-tuning are completed within this time.

7. The method for repairing gaps and loose suspension of elastic support blocks according to claim 1, characterized in that: In step (2), grouting holes are drilled symmetrically on both sides to overcome the irregularity of the empty area. By establishing a two-way grouting or one-injection-one-outlet fluid passage, the grouting material is ensured to achieve uniform and full filling of the three-dimensional space in the empty area and effectively remove air.

8. The method for repairing gaps and loose suspension of elastic support blocks according to claim 1, characterized in that: In step (7), the vibration operation is carried out using a special high-frequency vibrator that can operate across tracks.

9. The method for repairing gaps and slack in elastic support blocks according to claim 1, characterized in that: In step (4), the rail lifting device used to lift the rail is a specially designed device.

10. A system for repairing gaps in elastic support blocks used in implementing the method of any one of claims 1-9, characterized in that, Includes those that functionally cooperate with the steps of the method: A specially designed rail lifting device is used to lift the rails, along with the elastic support blocks and boots, to a limited height. An angled drilling device is used to drill grouting holes at a specified angle on an elastic support block. The cleaning device includes a high-pressure blowing device and a vacuuming device, used to alternately clean grooves and channels; Special grouting device is used to inject grouting material through grouting holes, measure the grouting volume in real time, and has a pressure maintenance function to maintain the pressure in the grouting system after grouting and before vibration. A cross-track dual-head high-frequency vibrator is used to compact the elastic support blocks after they have been placed. The limiting fixture, including a pull rod and a pad, is used to fix the position of the elastic support block during the fine-tuning stage.

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