In-situ replacement method for elastic supporting block of shoe

Abstract

This invention discloses an in-situ casting replacement method for elastic support block boots, comprising: determining the damaged location of the elastic support block boot; removing the fasteners around the elastic support block corresponding to the damaged boot; raising the rail to a preset height while simultaneously lifting the corresponding elastic support block; removing or dismantling the damaged and ineffective boot, and fixing an elastic pad and elastic strip at the bottom of the elastic support block; lowering the rail and support block into position, reinstalling the fasteners and performing fine adjustments; installing a boot casting auxiliary tool, and injecting liquid boot material into the cavity formed between the support block and the track bed through the boot casting auxiliary tool; after the material solidifies and reforms the boot, removing the boot casting auxiliary tool. Through the technical solution of this invention, the construction organization is optimized, construction efficiency is improved, and the problems of low overall replacement efficiency caused by numerous maintenance steps and long process transition times in traditional methods are solved, ensuring the quality of elastic support block boot repair.

Description

Technical Field

[0001] This invention relates to the field of road repair technology, and in particular to an in-situ casting replacement method for elastic support block boots. Background Technology

[0002] Ballastless track is widely used in tunnels of passenger and freight railways in my country, including types such as elastic support block type, double block type, long sleeper embedded type, and slab type. Furthermore, major cities are constructing subways to alleviate urban traffic pressure, all of which utilize ballastless track structures. However, track maintenance within tunnels is inconvenient. Considering factors such as reducing maintenance workload and improving track smoothness, ballastless track with lower maintenance requirements is suitable for long tunnels. Generally, elastic support block type ballastless track is used in tunnels of conventional passenger and freight railways exceeding 1 km in length. This structure is safe and reliable, offering good vibration reduction performance and better maintainability compared to other types of ballastless track. The elastic support block type cast-in-place concrete track bed is a ballastless track structure installed in special sections. From bottom to top, it consists of a concrete track bed, precast elastic shoes and pads, precast support blocks, fasteners, and rails. The precast elastic shoes, pads, and support blocks are key structures connecting the upper and lower sections, undertaking functions such as vibration reduction and force transmission. However, during the service life of the track structure, it is subjected to the effects of train cyclic dynamic load, temperature load, and rainwater washing and erosion. The elastic support shoes will deform and crack, and the vibration and impact under train load will be amplified, resulting in a reduction or loss of excellent vibration reduction effect. It will also cause track irregularity problems and varying degrees of damage to the track bed slab. It is necessary to replace the elastic support blocks to ensure the safety of the track structure.

[0003] Because railway maintenance work can only be carried out during maintenance windows, which are limited (generally only 3-4 hours), and due to limited track access conditions (only small access gates are allowed, preventing large equipment from being used), and because tunnels are long and access to maintenance work is limited to one end, coupled with the large amount of tooling involved, significant time is wasted traveling to and from the work site and moving various tools, thus impacting the efficiency of maintenance work on operating railways. Furthermore, the continuous impacts during operation cause the elastic support block bearing dimensions to increase and prefabricated shoe dimensions to become inaccurate. Replacing the prefabricated shoes will create gaps between the elastic support block and the track bed slab, affecting the track bed's performance. Therefore, how to quickly and safely replace and repair damaged elastic support block shoes within maintenance windows is a pressing problem that needs to be solved in this field.

[0004] In the existing technology, the paper "Research and Practice on Replacing Elastic Support Blocks in Urban Rail Transit" involves removing and replacing the damaged elastic support blocks as a whole, but it cannot repair the gap between the overshoe and the track bed concrete.

[0005] The papers "Research on the Treatment Scheme for Over-limit Track Bottom Slope of Elastic Support Block Ballastless Track in Tunnels" and "Damage Analysis and Treatment of Elastic Support Block Ballastless Track in Passenger and Freight Railways" involve the complete removal and replacement of damaged elastic support blocks. High-strength mortar or high-strength resin is injected again to repair the gap between the track shoe and the track bed concrete. During the track maintenance window, there are many procedures. The gap between the track shoe and the track bed slab is small, and it is difficult to fill it completely with high-strength mortar or high-strength resin to ensure quality.

[0006] The invention patent "A method for repairing the failure of rubber boots CN201510631495.2" describes a method that involves removing and replacing the damaged elastic support block as a whole. First, epoxy resin is applied to the support block and the concrete surface of the track bed. The boot is then bonded to the track bed concrete and the support block through an epoxy resin layer to repair the gap. However, for larger gaps, this method may cause damage or deformation to the boot or make it prone to gap formation. Summary of the Invention

[0007] To address the aforementioned problems, this invention provides an in-situ casting replacement method for elastic support block boots. By lifting the rail and elastic support block at the location of the damaged or failed boot, removing or taking out the damaged or failed boot, repositioning and fixing the rail and elastic support block, and then injecting liquid boot material into the cavity, the in-situ casting replacement of the boot is completed. This method optimizes construction organization, reduces process connections and the number of tools and equipment used, improves construction efficiency, simplifies and concentrates all construction processes within a single time window, and solves the problem of low overall replacement efficiency caused by numerous time window processes and long process connection times in traditional methods. Furthermore, the liquid boot material casting method allows the boot to adapt to the cavity size, ensuring the quality of the elastic support block boot repair.

[0008] To achieve the above objectives, the present invention provides an in-situ casting replacement method for an elastic support block sleeve, comprising:

[0009] Based on the test data of the track, the location of the damage to the elastic support block boot was determined;

[0010] Remove the fasteners within the preset range around the elastic support block corresponding to the damaged and failed boot;

[0011] Raise the rail at the location where the fastener was removed to a preset height, and at the same time lift the elastic support block at the corresponding location;

[0012] Remove or dismantle the damaged and ineffective boot, and fix the elastic pad and elastic strip at the bottom of the elastic support block;

[0013] Lower the rail and the support block into place, reinstall the fastener and make fine adjustments;

[0014] Install the auxiliary tooling for grouting, and use grouting equipment to inject liquid grouting material into the cavity formed between the support block and the track bed through the auxiliary tooling for grouting;

[0015] After the material in the cavity has solidified and reformed into a boot, the auxiliary tooling for casting the boot is removed.

[0016] In the above technical solution, preferably, the liquid boot material is an AB two-component material, the liquid boot material is mixed using a stirring and mixing device, and the boot casting auxiliary tooling is used for grouting.

[0017] In the above technical solution, preferably, the temperature of the liquid boot material is controlled at 20℃~50℃, the stirring time is 20~30 seconds, and the pouring time is 30~60 seconds.

[0018] In the above technical solution, preferably, the liquid boot material loses its workability within 30 to 60 seconds after injection and becomes surface dry within 5 to 10 minutes. The cured boot has a compression set of ≤20% and a static stiffness of 200 to 300 kN / mm.

[0019] In the above technical solution, preferably, the mixing equipment is used to uniformly mix AB two-component materials with different volume ratios, and the grouting flow rate of the shoe casting auxiliary tool is adjustable from 4 kg / min to 8 kg / min, and the grouting pressure is adjustable from 0 to 3 MPa.

[0020] In the above technical solution, preferably, the specific method for removing the fasteners within a preset range around the elastic support block corresponding to the damaged and failed boot includes:

[0021] Instead of removing the fasteners on the elastic support blocks corresponding to the damaged boots to be replaced, the fasteners on the elastic support blocks at intervals of 1 to 2 are removed in a skip-style manner.

[0022] In the above technical solution, preferably, the specific method of fixing the elastic pad and elastic strip at the bottom of the elastic support block includes:

[0023] The elastic pad is attached and fixed in the middle area of ​​the bottom of the elastic support block, and the elastic pad strip is attached and fixed around the bottom edges of the elastic support block.

[0024] In the above technical solution, preferably, the elastic pad protrudes 1 mm from the bottom edge of the elastic support block in its natural state, and is 1 mm thicker than the elastic pad plate.

[0025] In the above technical solution, preferably, the auxiliary tooling for the casting of the boot is a two-component grouting device or a two-component small grouting gun. The two-component grouting device is used for grouting by gun-type injection or pouring injection, and the two-component small grouting gun is used for direct injection.

[0026] In the above technical solution, preferably, the liquid level of the liquid boot material injected into the cavity is 5 to 10 mm higher than the surface of the track bed.

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows: by lifting the rail and elastic support block at the location of the damaged and failed boot, removing or taking out the damaged and failed boot, resetting and fixing the rail and elastic support block, and then injecting liquid boot material into the cavity, the in-situ casting and replacement of the boot is completed. This optimizes the construction organization, reduces the number of process connections and the number of tools and equipment, improves construction efficiency, simplifies and concentrates all construction processes within a single window, and solves the problem of low overall replacement efficiency caused by the large number of window processes and long process connection time in traditional methods. Moreover, the liquid boot material casting method allows the boot to adapt to the cavity size, ensuring the quality of boot repair for the elastic support block. Attached Figure Description

[0028] Figure 1 This is a schematic flowchart of an in-situ casting and replacement method for an elastic support block sleeve disclosed in an embodiment of the present invention.

[0029] Figures 2 to 6 This is a structural schematic diagram illustrating the implementation process of an in-situ casting and replacement method for an elastic support block sleeve disclosed in an embodiment of the present invention.

[0030] In the diagram, the correspondence between the components and the reference numerals is as follows:

[0031] 1. Rail; 2. Fastener; 3. Elastic support block; 3-1. Support block; 3-2. Elastic pad; 3-3. Rubber boot; 4. Track bed; 5. Elastic pad strip; 6. Auxiliary tooling for boot casting; 7. Boot. Detailed Implementation

[0032] 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, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] The present invention will now be described in further detail with reference to the accompanying drawings:

[0034] like Figure 1 As shown, the in-situ casting replacement method for an elastic support block sleeve according to the present invention includes:

[0035] Based on the test data of the track, the location of the damage to the elastic support block shoe 7 was determined;

[0036] Remove the fasteners 2 within the preset range around the elastic support block 3 corresponding to the damaged and ineffective boot 3-3;

[0037] Raise the rail 1 at the position of the removed fastener 2 to a preset height, and at the same time lift the elastic support block 3 at the corresponding position;

[0038] Remove or dismantle the damaged and ineffective boot 3-3, and fix the elastic pad 3-2 and elastic pad strip 5 at the bottom of the elastic support block 3;

[0039] Lower rail 1 and support block into place, reinstall fastener 2 and make fine adjustments;

[0040] Install the auxiliary tooling 6 for grouting and inject the liquid grouting material into the cavity formed between the support block 3-1 and the track bed 4 using the grouting equipment.

[0041] After the material in the cavity has solidified and reformed into the boot 7, the auxiliary tooling 6 for casting the boot is removed.

[0042] In this embodiment, by lifting the rail 1 and elastic support block 3 at the damaged and failed boot 3-3 position, removing or taking out the damaged and failed boot 3-3, and then resetting and fixing the rail 1 and elastic support block 3, liquid boot material is injected into the cavity to complete the in-situ casting and replacement of the boot 7. This optimizes the construction organization, reduces the number of process connections and the number of tools and equipment, improves construction efficiency, simplifies and concentrates all construction processes within a single window, and solves the problem of low overall replacement efficiency caused by numerous window processes and long process connection time in traditional methods. Moreover, the liquid boot material casting method allows the boot 7 to adapt to the cavity size, ensuring the repair quality of the boot 7 on the elastic support block 3.

[0043] Specifically, the in-situ casting replacement method for elastic support block boots during implementation includes: locking rail temperature test and initial data acquisition → determining and marking the position of the failed elastic support block 3 → loosening fasteners 2 within a certain range → lifting rail 1 and removing support block 3-1 at the position of the boot to be replaced 7 → removing the failed boot 7 and rubber elastic pad → re-fixing the rubber elastic pad (support block 3-1 is not damaged) → lowering the rail and positioning support block 3-1 → installing fasteners 2 and fine-tuning the track → injecting liquid boot material → restoring the track.

[0044] In the above embodiments, preferably, the liquid boot material is an AB two-component material, the liquid boot material is mixed using a dedicated stirring and mixing equipment, and poured using a dedicated boot casting auxiliary tool 6.

[0045] In the above embodiments, preferably, the liquid boot material needs to be directly heated on-site before injection, or the liquid boot material needs to be preheated and then kept warm to control the temperature of the liquid boot material between 20℃ and 50℃. The mixing time in the mixing equipment is 20 to 30 seconds, the injection time is 30 to 60 seconds, and the injection is completed within 90 seconds. Furthermore, the liquid boot material loses its workability within 30 to 60 seconds after injection, is surface dry within 5 to 10 minutes, and meets the conditions for traffic opening 1 to 1.5 hours after injection. The cured boot 7 has a compression set ≤ 20% and a static stiffness of 200 to 300 kN / mm.

[0046] In the above embodiments, preferably, the mixing equipment is used to uniformly mix AB two-component materials with different volume ratios, the grouting flow rate of the shoe casting auxiliary tool 6 is adjustable from 4 kg / min to 8 kg / min, the grouting pressure is adjustable from 0 to 3 MPa, and it is small in size and light in weight, not exceeding 50 kg.

[0047] In the above embodiments, preferably, the specific method for removing the fasteners 2 within a preset range around the elastic support block 3 corresponding to the damaged and failed boot 3-3 includes:

[0048] Instead of removing the fasteners 2 on the elastic support blocks 3 at the corresponding positions of the damaged boots 7, the fasteners 2 on the elastic support blocks 3 at intervals of 1 to 2 are removed in a skip-style manner.

[0049] In the above embodiments, preferably, the specific method of fixing the elastic pad 3-2 and the elastic pad strip 5 at the bottom of the elastic support block 3 includes:

[0050] A fixed elastic pad 3-2 is attached to the bottom center area of ​​the elastic support block 3, and a fixed elastic pad strip 5 is attached to the bottom perimeter of the elastic support block 3.

[0051] In the above embodiments, preferably, the elastic pad 5 protrudes about 1 mm from the bottom edge of the elastic support block 3 in its natural state, and is 1 mm thicker than the elastic pad 3-2, making the elastic pad 5 more prone to deformation.

[0052] In the above embodiments, preferably, the auxiliary tooling 6 for grouting the boot is a two-component grouting device or a two-component small grouting gun. The two-component grouting device is used for grouting by gun-type injection or pouring injection, and the two-component small grouting gun is used for direct injection.

[0053] In the above embodiment, preferably, the liquid level of the liquid boot material injected into the cavity is 5 to 10 mm higher than the surface of the track bed 4.

[0054] The in-situ casting and replacement method for the elastic support block sleeve disclosed in the above embodiments is implemented with reference to the following examples:

[0055] Example 1

[0056] Under repeated impact loads and the combined effects of dust and rainwater, the elastic support block boots 7 of the railway line suffer damage and failure, and gaps appear around their perimeter, requiring replacement and repair. The construction process for replacing the liquid support boots 7 using the method of this invention is as follows: Figure 1 As shown, the specific content is as follows:

[0057] (1) Preparation stage

[0058] 1) Locking rail temperature test and initial data acquisition

[0059] The actual locking rail temperature was tested using a seamless track actual locking rail temperature detection system. The actual temperature of rail 1 was also tested and compared with the actual locking rail temperature to determine the loosening length of fastener 2. Monitoring sensors were then installed.

[0060] 2) Marking position 3-3 for injury loss effective boots

[0061] Mark the location of the damaged and ineffective boot 3-3 and measure the track geometry at that location, record the data, and at the same time, mark the range of loose fastener 2 according to the track temperature test.

[0062] (2) Implementation phase (e.g.) Figures 2 to 6 (As shown)

[0063] 1) Loosen the fasteners within a certain range.

[0064] Check the rail temperature, and remove fasteners 2 sequentially according to the length range corresponding to the rail temperature, but do not remove fasteners 2 at the location of the replacement shoe 7. If it is an intermittent replacement due to damage, remove fasteners 2 as described above; if it is a replacement due to continuous damage, in order to avoid adding the process of adjusting the rail geometry, it is recommended to remove fasteners 2 in a skip-step manner, replacing every 1-2 elastic support block shoes 7 with one elastic support block 3 remaining stationary. After removing fasteners 2, place the adjusting shims neatly next to the support block 3-1 to prevent the fasteners 2 from being installed incorrectly, which would affect the smoothness of the rail.

[0065] 2) Lift rail 1 and remove the support block 3-1 at position 7 of the replacement shoe.

[0066] After fastener 2 is removed, a rail lifting device is installed at a certain interval to lift the rail by 1200mm to 250mm. At the same time, the support block 3-1 at the position of the replacement boot 7 is lifted to a certain height (to facilitate the removal of the damaged and ineffective boot 3-3 and the rubber elastic pad).

[0067] 3) Remove the faulty boot 7 and rubber elastic pad.

[0068] After the support block 3-1 is removed, if the boot 7 is removed along with the support block 3-1, the damaged or ineffective boot 7 and the rubber elastic pad are removed from the support block 3-1; if the boot 7 is not removed and is in the groove of the track bed 4, the damaged or ineffective boot 7 and the rubber elastic pad are removed from the groove using auxiliary tools, and the debris in the groove is cleaned.

[0069] 4) Re-fix the rubber elastic pad

[0070] A layer of liquid adhesive is applied to the bottom of the support block 3-1, and the rubber elastic pad is then attached and fixed to the bottom of the support block 3-1. An elastic strip 5 is attached around the perimeter of the elastic boot 7 pad. The elastic strip 5 protrudes about 1mm from the bottom edge of the support block 3-1 and is 1mm thicker than the elastic rubber pad. The elastic strip 5 is easily deformable to ensure that the liquid boot 7 does not affect the vertical displacement of the support block 3-1 after molding and that the rubber elastic pad has sufficient deformation space.

[0071] 5) Lower the rail and position the support block 3-1.

[0072] Lower rail 1 so that support block 3-1 is positioned in the concrete groove of track bed 4.

[0073] 6) Install fastener 2 and fine-tune the track.

[0074] After the rail 1 is in place, install the fastener 2 in one go. Pay attention to the position of the fastener 2 during installation to ensure that the fastener 2 is in the same position as before. At the same time, adjust the geometry of the rail and ensure that there is about 7mm of space around the base of the support block 3-1 (i.e., the original thickness space of the boot 7).

[0075] 7) Liquid injection boots 7

[0076] After the track is finely adjusted, prepare the liquid boot material and mix and inject it using a special mixing equipment, with auxiliary injection tools used during injection.

[0077] First, before grouting, different sealing methods are selected according to the different pouring methods of the liquid grouting boot 7. If the replacement volume of the grouting boot 7 on site is large, a multi-functional two-component grouting equipment gun injection or on-site direct mixing and pouring grouting method is adopted; if the replacement volume of the grouting boot 7 on site is small, a two-component small grouting gun direct injection method is adopted.

[0078] If a multi-functional two-component grouting equipment is used for gun-type injection or a two-component small grouting gun for direct injection, then a 10mm wide and 5mm thick adhesive strip can be pasted 5mm away from the four surfaces of the track bed around the groove. If the on-site direct mixing and pouring method is used, then a 10mm wide and 5mm thick adhesive strip can be pasted 5mm away from the four surfaces of the track bed around the groove, and grouting can be assisted by an eagle-beak type guide channel or by installing a lotus leaf-shaped auxiliary grouting tool 5mm away from the four surfaces of the track bed around the groove.

[0079] The liquid boot material is composed of component A and component B. It is made of multi-functional two-component grouting equipment. Components A and B do not need to be preheated. The equipment has its own heating function and can heat them directly on site. The construction is carried out by direct on-site mixing and two-component small grouting gun. It is necessary to preheat and keep the A and B materials warm.

[0080] The liquid boot material is temperature controlled between 20℃ and 50℃. It is an adaptive, self-leveling, and well-filled material, ensuring its injectability. At the same time, it ensures uniform mixing. The stirring time of the liquid boot material is 20s to 30s, the pouring time is 30s to 60s, the pouring is completed within 90s, it loses its fluidity in 120s, it is surface dry in 7 to 12 minutes, and it reaches the conditions for traffic opening after 1h to 1.5h. The compression set is ≤20%, and the static stiffness is 200-300kN / mm.

[0081] After the liquid injection boot 7 operation is performed, there is no need to perform seam separation treatment.

[0082] 8) Line restoration and adjustment

[0083] The track inspection trolley was used to test the loosened fasteners in section 2, and the track condition met the operational requirements.

[0084] 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 of in-situ replacement of an elastomeric pad sleeve shoe, characterized by, include: Based on the test data of the track, the location of the damage to the elastic support block boot was determined; Remove the fasteners within a preset range around the elastic support block corresponding to the damaged and failed boot. However, do not remove the fasteners on the elastic support block corresponding to the damaged boot to be replaced. Instead, remove the fasteners on the elastic support blocks at intervals of 1 to 2. Raise the rail at the location where the fastener was removed to a preset height, and at the same time lift the elastic support block at the corresponding location; Remove or dismantle the damaged and ineffective boot, and fix an elastic pad and an elastic strip at the bottom of the elastic support block. The elastic pad is attached and fixed in the middle area of ​​the bottom of the elastic support block, and the elastic strip is attached and fixed around the bottom edges of the elastic support block. The elastic strip protrudes 1 mm from the bottom edge of the elastic support block in its natural state and is 1 mm thicker than the elastic pad. Lower the rail and the support block into place, reinstall the fastener and make fine adjustments; Install the auxiliary tooling for grouting. Seal the edges by attaching a 10 mm wide and 5 mm thick adhesive strip around the groove of the track bed corresponding to the elastic support block, 5 mm above the track bed surface. Then, use grouting equipment to inject the liquid grouting material, which is a mixture of component A and component B, into the cavity formed between the support block and the track bed through the auxiliary tooling. The temperature of the liquid grouting material is 20-50°C, the stirring time is 20-30 seconds, the grouting time is 30-60 seconds, and the liquid level of the injected liquid grouting material is 5-10 mm above the track bed surface. After the material in the cavity solidifies and reforms into a boot, the auxiliary tooling for casting the boot is removed. The liquid boot material loses its workability 30-60 seconds after injection and is surface dry in 5-10 minutes. The compression set of the cured boot is ≤20%, and the static stiffness is 200-300 kN / mm.

2. The in-situ replacement method of the elastic support block sleeve boots according to claim 1, characterized in that, The liquid boot material is an AB two-component material. The liquid boot material is mixed using a stirring and mixing device and then poured using the boot casting auxiliary tooling.

3. The in-situ replacement method of the elastic support block sleeve boots according to claim 2, characterized in that, The mixing equipment is used to uniformly mix AB two-component materials with different volume ratios. The grouting flow rate of the shoe casting auxiliary tool is adjustable from 4 kg / min to 8 kg / min, and the grouting pressure is adjustable from 0 to 3 MPa.

4. The in-situ replacement method of the elastic support block sleeve boots according to claim 3, characterized in that, The auxiliary tooling for the casting of the boots uses a two-component grouting device or a two-component small grouting gun. The two-component grouting device uses a gun-type injection or pouring-in grouting method for grouting, while the two-component small grouting gun uses a direct injection method.

Images