Maintenance and construction method for fabricated elastic solidified ballast bed

Abstract

The invention discloses a method for replacing an assembled elastic solidified ballast bed. The method comprises a preparation stage, a replacement stage and a recovery stage, a construction reference is established through data measurement, a special gantry crane temporary track is laid, the crack resistance of buttresses is strengthened, and a steel rail kerf releases temperature stress, so that high-precision and high-stability operation conditions are provided for subsequent construction; in the replacement stage, efficient replacement of sleepers and nondestructive repair of a ballast bed structure are achieved by adopting a transverse rail shifting cooperation slideway low-resistance design, a new sleeper indirect fine adjustment technology and a dynamic mortar pouring technology; and in the recovery stage, the railway ballast compactness is optimized through high-frequency tamping, a heat affected zone is reduced through narrow-gap welding, and track smoothness and structural integrity are recovered based on BIM line fine adjustment. According to the method, efficient replacement of the assembly type elastic curing ballast bed is achieved, the construction efficiency is improved to the maximum extent, damage to the steel rail is reduced, high creativity and practicability are achieved, and the method is suitable for maintenance and replacement work of various railway tracks.

Description

TECHNICAL FIELD

[0001] The application relates to a construction method, in particular to a prefabricated elastic solidification track bed maintenance construction method. BACKGROUND

[0002] The traditional method adopts fixed-length rail cutting, which leads to a long construction window period and is prone to rail thermal expansion and cold contraction problems due to the lack of temperature stress calculation; the temporary track pier of the gantry crane is mostly poured with ordinary concrete, which has a long solidification time and poor crack resistance, thereby affecting the construction progress. The rail tie fine adjustment relies on manual experience and lacks coordinated control with the solidification track ballast and mortar bag, which is prone to track alignment deviation. SUMMARY

[0003] In order to solve the defects in the prior art, the application discloses a prefabricated elastic solidification track bed maintenance construction method, and the technical scheme is as follows: A prefabricated elastic solidification track bed replacement method, characterized by comprising a preparation stage, a replacement stage and a recovery stage: The preparation stage: through data measurement, a construction reference is established, a gantry crane temporary track is laid, the crack resistance of the pier is strengthened, the temperature stress of the rail cutting joint is released, and high-precision and high-stability operation conditions are provided for subsequent construction; The replacement stage: the transverse rail shifting is cooperated with the low-resistance design of the slide, the indirect fine adjustment technology of the new rail tie and the dynamic mortar pouring process, so that the rail tie is efficiently replaced and the track bed structure is repaired without damage; The recovery stage: the track ballast compactness is optimized through high-frequency tamping, the heat-affected zone is reduced through narrow-gap welding, and the track smoothness and structural integrity are recovered through the line fine adjustment based on BIM.

[0004] Preferably, the preparation stage comprises data measurement, laying of the gantry crane temporary track, removal of the track ballast on both sides and between the ties, and rail cutting joint, wherein: Data measurement: three-dimensional modeling of the track alignment is performed by combining a total station and a laser scanner; Laying of the gantry crane temporary track: a stable support platform is provided for the gantry crane to ensure track smoothness and prevent local settlement, including (1) pier design: the longitudinal distance between the piers, i.e. the distance of the non-removed section and the distance of the removed section, is determined; the bending bearing capacity of the pier size is verified through finite element simulation; (2) Material and structure: fast-hardening polymer concrete; glass fiber cloth is laid at intervals, with a tensile strength of greater than or equal to 100 MPa, to improve the crack resistance of the pier; (3) Installation process: a non-woven fabric isolation layer is laid on the inner side of the formwork; the channel steel is fixed to the pier by expansion screws, and the lap joint is seamlessly treated.

[0005] The two sides and the inter-pillar ballast removal: clean the working surface to the inverted arch backfill layer, provide unobstructed construction space for the replacement of the sleeper, including (1) layered removal of unhardened ballast, depth to the surface of the inverted arch; (2) removal of ballast protection temporary storage: evenly spread on the adjacent track or bagged in the integrated cavern.

[0006] The rail cutting: release the rail temperature stress, avoid the track deformation caused by thermal expansion and contraction during construction, including: (1) limit the length of the cutting, calculated according to the rail temperature stress formula; (2) when ΔT≤20℃, the expansion amount ΔL, match the gap design of the clamp plate, completely absorb the expansion amount; (3) use the clamp plate to connect the cutting rail, disassemble the clamp plate every day to cooperate with the rail shifting operation, and restore the seamless after construction.

[0007] Preferably, the replacement stage includes the following steps: 1) Remove the fastener Remove the fastener in the rail shifting section, for seamless rails, the length of the fastener to be removed should be calculated according to the difference between the working temperature and the locked rail temperature; 2) Transverse rail shifting Install the transverse rail shifting equipment, including the rail shifting tool, the rail slide and the anti-slip device. The rail shifting tool is used for seamless rails and large super-elevation sections of jointed rails; the rail slide is used for all rail shifting sections; the anti-slip device is used for jointed rail sections with large longitudinal slope; 3) Assemble the gantry crane Remove the fastener and shift the rail at the same time, assemble and debug the gantry crane, and unload the new sleeper from the rail flat car; 4) Unload the new sleeper from the rail flat car After the gantry crane is assembled and debugged, use the gantry crane to unload the new sleeper from the rail flat car and transport it longitudinally to the replacement sleeper position for temporary storage; 5) Remove the old sleeper Use the gantry crane to lift, transport and load the old sleeper onto the rail flat car; after the old sleeper is loaded, remove the gantry crane and load it onto the rail flat car; 6) Return the rail and install the fastener Use the rail shifting tool or manpower to return the rail to its original position and install the fastener, including the fastener for the newly replaced sleeper.

[0008] 7) Fine adjustment of the new sleeper After the new sleeper is hung on the rail with the fastener, the position of the new sleeper is indirectly adjusted by adjusting the position of the rail with a lead screw; 8) Grouting of the mortar bag Lay the mortar grouting bag under the sleeper hardened ballast and refill the sand layer.

[0009] Preferably, 1) restore the ballast on both sides and between the sleepers Use the subsequent window to refill and tamp the ballast on both sides of the line and between the sleepers.

[0010] 2) Remove the gantry crane temporary track Remove the gantry crane temporary track and temporary support pier, and restore the appearance of the ballast.

[0011] 3) Steel rail welding For the concentrated replacement section of the cut rail, steel rail welding should be carried out, and long rails should be replaced according to the situation.

[0012] 4) Track fine adjustment After all the sleepers are replaced, the track fine adjustment or the track is lifted in the construction section to restore the smoothness of the line, and the construction range is gradually speeded up.

[0013] Preferably, the transverse rail shifting includes: rail shifting distance 800-850mm, hydraulic jacking device (pushing force ≥10T) is used to shift the steel rail; the surface of the rail slide is coated with a polytetrafluoroethylene coating, the friction coefficient is ≤0.1, and the rail shifting resistance is reduced by 30%.

[0014] Preferably, the new sleeper fine adjustment adopts bidirectional screw indirect adjustment of the position of the steel rail, the pitch accuracy is ±0.02mm, the laser displacement sensor is used to monitor the adjacent mortar bag gap value ≤0.3mm, and the sleeper positioning accuracy is ensured to be ±0.5mm.

[0015] Preferably, the mortar bag pouring dynamically selects single sleeper or double sleepers according to the sleeper spacing, and uses fluidity mortar with slump 180±20mm, and the filling density is ≥95%.

[0016] Preferably, the steel rail welding adopts narrow gap flash welding: for the 50m short rail after cutting, the welding heat affected zone is ≤20mm.

[0017] Preferably, the track fine adjustment is a dynamic adjustment based on BIM: the track alignment data before and after construction is imported into the BIM model to generate a fine adjustment vector diagram to guide the lifting and shifting machine to adjust with an accuracy of 0.1mm, and finally the line smoothness (TQI index) is ≤2.0.

[0018] The application also discloses a railway track maintenance method, which is realized by using the above-mentioned assembly type elastic solidified ballast replacement method when the old sleepers and solidified ballast are replaced by new sleepers and solidified ballast after rail shifting. Advantages

[0019] The efficient replacement of the assembly type elastic solidified ballast bed is realized, the construction efficiency is maximized, and the damage to the steel rail is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 The process flow chart and device schematic diagram of the application are shown. DETAILED DESCRIPTION

[0021] An assembled elastic solidified track bed replacement method, characterized by comprising a preparation stage, a replacement stage and a recovery stage: The preparation stage: through data measurement, establish construction reference, lay gantry crane temporary track and strengthen pier crack resistance, rail joint cutting releases temperature stress, provide high precision, high stability operation condition for subsequent construction.

[0022] The preparation stage includes data measurement, laying gantry crane temporary track, both sides and ballast removal, rail joint cutting, wherein: Data measurement: adopt total station and laser scanner combination, three-dimensional modeling for track alignment, combined with fastener adjustment amount (dynamic monitoring through torque sensor) and ballast thickness (ultrasonic thickness gauge) data, generate digital construction reference. Traditional method relies on manual measurement, large error and time-consuming. The invention improves the precision to ±0.5mm through digital modeling, provides high precision reference for subsequent fine adjustment.

[0023] Laying gantry crane temporary track: provide stable support platform for gantry crane, ensure track smoothness and prevent local settlement, including (1) temporary pier design: temporary pier longitudinal spacing 6m (non-removal area) and 3m (removal area): based on track load distribution and pier bearing capacity calculation, ensure that the pier spacing is encrypted to 3m when the local load in the removal section increases, to prevent track settlement.

[0024] Pier size 400mmx500mmx≥100mm: verified by finite element simulation, meet the bending moment bearing demand of gantry crane walking channel steel (channel steel specification is 18#); (2) material and structure: fast hardening polymer concrete: add early strength agent (such as sulphoaluminate cement) and polymer fiber, make the strength of pier reach 20MPa within 12 hours, shorten the construction period; glass fiber cloth is laid at intervals: lay a layer of glass fiber cloth (tensile strength ≥100MPa) every 100mm height, significantly improve the crack resistance of pier, avoid the crack propagation of traditional concrete pier caused by vibration. The traditional pier needs to be cured for more than 24 hours and is easy to crack. The invention shortens the pier construction time by 50% and improves the crack resistance by 3 times through material and structure optimization.

[0025] (3) installation process: non-woven fabric isolation layer is laid inside the formwork; channel steel is fixed with pier through expansion screw, and the lap joint is seamless.

[0026] The both sides and ballast removal: clean the working surface to the inverted arch backfill layer, provide barrier-free construction space for sleeper replacement, including (1) layered removal of unhardened ballast, depth to the surface of inverted arch; (2) removal of ballast protective temporary storage: evenly spread on adjacent track or bagged in comprehensive cavern.

[0027] The rail cutting seam: release rail temperature stress, avoid track deformation caused by thermal expansion and contraction during construction, comprising: (1) limit the cutting seam length, according to the calculation of rail temperature stress formula; (2) when ΔT≤20℃, the expansion amount ΔL, the gap design of the clamping plate is matched, and the expansion amount is completely absorbed; (3) the clamping plate is used to connect the cutting seam rail, the clamping plate is disassembled and matched with the rail shifting operation every day, and the seamless is restored after construction. The traditional cutting seam length is random, which is easy to cause the rail stress to exceed the limit. The present application limits the cutting seam length by theoretical calculation, and dynamically adjusts the clamping plate gap to eliminate the influence of temperature stress on the smoothness of the track.

[0028] Replacement stage: adopt transverse rail shifting cooperates with low resistance design of slide, indirect fine adjustment technology of new rail sleeper and dynamic mortar pouring process, realize efficient replacement of rail sleeper and non-destructive repair of track bed structure; The replacement stage comprises the following steps: 1) Remove the fastener Remove the fastener of the rail shifting section, and for seamless rail, the length of the fastener to be removed should be calculated according to the difference between the operation temperature and the locking rail temperature; 2) Transverse rail shifting Install the transverse rail shifting equipment, including the rail shifting tool, the rail slide and the anti-slip device. The rail shifting tool is used for seamless rail and large super-high section of jointed rail; the rail slide is used for all rail shifting sections; the anti-slip device is used for large longitudinal slope jointed rail section; Rail shifting distance 800~850mm: according to the width of the rail sleeper (the standard rail sleeper width is 300mm) and the operation space requirement, through simulation verification, 800mm is the minimum safety distance (to avoid collision with the edge of the rail sleeper), and 850mm is the maximum economic distance (to reduce the length of the rail slide).

[0029] Rail shifting tool and slide cooperative design: The rail shifting tool adopts hydraulic pushing device (pushing force≥10T), which is suitable for seamless rail shifting of large super-high section (curve radius≤800m).

[0030] The surface of the rail slide is coated with polytetrafluoroethylene coating (friction coefficient≤0.1), which reduces the rail shifting resistance by 30%.

[0031] The traditional rail shifting relies on manpower or single machine, which is low in efficiency and easy to damage the fastener. The present application improves the rail shifting efficiency by 2 times through equipment cooperative design and parameter optimization, and the rail resetting accuracy reaches ±1mm.

[0032] 3) Assemble the gantry crane Remove the fastener, shift the rail, and simultaneously assemble and debug the gantry crane and unload the new rail sleeper; 4) Unload the new rail sleeper After the gantry crane is assembled and debugged, the new rail sleeper is unloaded from the rail flat car by the gantry crane and longitudinally transported to the replacement rail sleeper position for temporary storage; 5)Remove old sleeper Lifting the old sleeper with gantry crane, transporting and loading it onto the rail flatcar; after loading the old sleeper, dismount the gantry crane and load it; 6)Back the rail and install the fastener Back the rail to its original position with rail backer or manpower, install the fastener, including the fastener for the new sleeper.

[0033] 7)Fine adjustment of new sleeper After the new sleeper is hung on the rail with the fastener, the position of the new sleeper is indirectly adjusted by adjusting the position of the rail with a lead screw; the two-way lead screw (pitch 5mm, accuracy ±0.02mm) is used to adjust the lateral position of the rail, and the displacement of the sleeper is indirectly controlled through the rigid connection between the rail and the sleeper fastener. During adjustment, the gap value of the adjacent mortar bag is monitored in real time (monitored by laser displacement sensor, threshold ≤0.3mm) to ensure that the existing solidified layer is not damaged during fine adjustment.

[0034] The traditional fine adjustment directly moves the sleeper, which easily disturbs the ballast layer. The present invention indirectly adjusts the rail, with an accuracy of ±0.5mm, and avoids the gap of the mortar bag.

[0035] 8)Mortar bag filling Lay the mortar filling bag under the sleeper solidified ballast and refill the filling layer mortar.

[0036] Flexible adjustment of longitudinal length: dynamically select single sleeper (600mm) or double sleeper (1200mm) filling according to the sleeper spacing (standard 600mm), replace the original design of 3m fixed length. Through the matching of fluidity mortar (slump 180±20mm) and bag tensile strength (≥5kN / m), the filling density is ensured to be ≥95%.

[0037] Traditional fixed length filling easily leads to material waste or non-dense filling. The present invention dynamically adjusts, with a material utilization rate of 20% and a density compliance rate of 98%.

[0038] Restoration stage: restore the track smoothness and structural integrity through high-frequency tamping to optimize the ballast density, narrow gap welding to reduce the heat affected zone, and BIM-based line fine adjustment.

[0039] Ballast tamping: high-frequency pneumatic tamping machine: use a tamping head with a vibration frequency of 40Hz and an excitation force of 5kN, combined with ballast grading optimization (particle size 10~30mm accounting for ≥70%), to increase the lateral resistance of the ballast bed to 12kN / sleeper (traditional method 8kN / sleeper).

[0040] Rail welding: narrow gap flash welding: for 50m short rail after cutting, narrow gap welding (gap 8~10mm) is adopted, welding heat affected zone ≤20mm (traditional arc welding is 50mm), which significantly reduces welding residual stress.

[0041] Line fine adjustment: dynamic adjustment based on BIM: import track alignment data before and after construction into BIM model, generate fine adjustment vector diagram, guide the adjustment of the track jack according to 0.1mm level accuracy, and finally the line smoothness (TQI index) ≤2.0 (traditional method is 3.5).

[0042] The application proposes an assembled elastic solidified ballast replacement scheme, including process flow and detailed construction scheme. The overall scheme is to replace the old sleeper and solidified ballast with new sleeper and solidified ballast after rail shifting. For concentrated replacement, the rail shifting method after cutting is adopted to maximize construction efficiency; for scattered replacement, the rail shifting method after cutting is adopted to minimize damage to the rail.

[0043] The above shows and describes the basic principles, main features and advantages of the present application. Those skilled in the art should understand that the present application is not limited to the above examples, and the above examples and descriptions in the specification are only the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the claimed present application. The scope of protection required by the present application is defined by the appended claims and their equivalents.

Claims

1. A method for replacing an assembled elastically cured roadbed, characterized in that: It includes the preparation phase, replacement phase and recovery phase: Preparation phase: Establish construction benchmarks through data measurement, lay temporary gantry crane tracks, strengthen pier crack resistance, and cut rails to release temperature stress, providing high-precision and high-stability working conditions for subsequent construction; Replacement phase: Adopting the low-resistance design of the transverse rail-pulling coordinated slideway, indirect fine-tuning technology for new sleepers, and dynamic mortar pouring technology to achieve efficient sleeper replacement and non-destructive repair of the trackbed structure; Restoration phase: Optimize ballast density through high-frequency tamping, reduce heat-affected zone through narrow-gap welding, and fine-tune the line based on BIM to restore track smoothness and structural integrity.

2. The method according to claim 1, characterized in that The preparation phase includes data measurement, laying of temporary gantry crane tracks, ballast removal on both sides and between sleepers, and rail cutting, among which: Data measurement: A total station and laser scanner are used to perform three-dimensional modeling of the track alignment; Laying temporary tracks for gantry cranes: providing a stable support platform for the gantry cranes, ensuring the smoothness of the tracks and preventing local settlement, including (1) pier design: determining the longitudinal spacing between piers, i.e. the distance between the non-removed sections and the distance between the removed sections; the pier size is verified by finite element simulation for bending bearing capacity; (2) Materials and structure: Rapid-hardening polymer concrete; fiberglass cloth laid at intervals, with a tensile strength of ≥100 MPa, to improve the crack resistance of the pier; (3) Installation process: a non-woven fabric isolation layer is laid on the inside of the template; the channel steel is fixed to the pier through expansion screws, and the overlap is seamlessly processed; The ballast removal on both sides and between the sleepers: cleaning the working surface to the backfill layer of the invert arch to provide an unobstructed construction space for sleeper replacement, including (1) removing the uncured ballast in layers to the depth of the invert arch surface; (2) protective temporary storage of the removed ballast: evenly spreading it on the adjacent tracks or bagging it and storing it in the integrated tunnel; The rail slit is designed to release the rail temperature stress and avoid rail deformation due to thermal expansion and contraction during construction, including: (1) limiting the slit length, which is determined by calculation based on the rail temperature stress formula; (2) when ΔT≤20°C, the expansion and contraction ΔL is matched with the gap design of the splints to fully absorb the expansion and contraction; (3) using splints to connect the slit rails, disassembling and assembling the splints daily to cooperate with the rail shifting operation, and restoring the seamless state after construction.

3. The method according to claim 1, characterized in that The replacement phase includes the following steps: 1) Remove the fasteners Remove the fasteners in the rail-shifting section. For seamless rails, the length of the fasteners removed should be determined based on the difference between the operating temperature and the locked rail temperature. 2) Horizontal rail Install transverse rail shifting equipment, including rail shifting fixtures, rail slides, and anti-slip devices. The rail shifting fixtures are used for seamless rails and large superelevation sections with seamed rails. The rail slides are used for all rail shifting sections. The anti-slip devices are used for seamed rail sections with large longitudinal slopes. 3) Assembling the gantry crane Remove fasteners, shift rails, and simultaneously assemble and debug the gantry crane and unload new sleepers; 4) Unloading of new sleepers After the gantry crane is assembled and debugged, the new sleepers are unloaded from the rail flat car using the gantry crane and transported longitudinally to the replacement sleeper location for temporary storage; 5) Remove old sleepers Use the gantry crane to lift, transport and load the old sleepers onto the rail flat car; after the old sleepers are loaded onto the car, remove the gantry crane and load the car; 6) Return the rails and install the fasteners Use rail derailleurs or manual derailleurs to reset rails and install fasteners, including those for newly replaced sleepers; 7) Fine-tuning of new sleepers After the new sleeper is hung on the rail with fasteners, the position of the new sleeper is indirectly adjusted by adjusting the position of the rail through the screw; 8) Mortar bag pouring Lay mortar pouring bags under the solidified ballast of the sleeper and re-fill the filling layer mortar.

4. The method according to claim 1, wherein The recovery phase includes the following steps: 1) Ballast restoration on both sides and between sleepers Utilize subsequent skylights to refill and tamp the ballast on both sides of the track and between sleepers; 2) Dismantle the temporary track of Longmen Long Remove the temporary tracks and temporary piers of the gantry crane and restore the appearance of the ballast; 3) Rail welding For rails that have been slit in the centralized replacement section, rail welding should be performed and long rails should be replaced as appropriate; 4) Line fine-tuning After all sleepers are replaced, the track will be fine-tuned or shifted in the construction section to restore the smoothness of the line, and the speed will be increased step by step in the construction area.

5. The method according to claim 3, characterized in that The horizontal rail shifting includes: a rail shifting distance of 800~850mm, a hydraulic pushing device with a thrust of ≥10T, and shifting the rails; the surface of the rail slide is coated with a polytetrafluoroethylene coating with a friction coefficient of ≤0.1, reducing the rail shifting resistance by 30%.

6. The method according to claim 3, characterized in that The new sleeper fine-tuning adopts a bidirectional lead screw to indirectly adjust the rail position, with a pitch accuracy of ±0.02mm. The gap between adjacent mortar bags is monitored by a laser displacement sensor ≤0.3mm, ensuring the sleeper positioning accuracy of ±0.5mm.

7. The method according to claim 3, characterized in that The mortar bag pouring is performed by dynamically selecting single or double sleepers according to the sleeper spacing, using fluid mortar with a slump of 180±20mm and a filling density of ≥95%.

8. The method according to claim 4, characterized in that The rail welding adopts narrow gap flash welding: for the 50m short rail after cutting, the welding heat affected zone is ≤20mm.

9. The method according to claim 4, characterized in that The line fine-tuning is a dynamic adjustment based on BIM: the track alignment data before and after construction are imported into the BIM model, a fine-tuning vector diagram is generated, and the track lifting and aligning machine is guided to adjust with an accuracy of 0.1mm. The final line smoothness TQI index is ≤2.

0.

10. A railway track maintenance method, wherein after derailing, the old sleepers and cured ballast are replaced with new sleepers and cured ballast using the assembled elastic cured ballast replacement method according to claim 1.

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