Method for laying seamless track ballastless track on long-span highway-railway bridge

Abstract

The application provides a seamless line ballastless track laying method on a highway-railway dual-purpose long-span bridge, and steps are as follows: track material is transported to a highway layer above a track laying operation surface; the track material is hoisted from the highway layer to the track laying operation surface; track sleepers are laid according to a designed track sleeper interval to a designed position; a seamless long rail strip traction and conveying mechanism is installed between the highway layer and the auxiliary track laying operation surface; the seamless long rail strip is transported to a terminal point of the laid ballastless track; the highway layer vehicle is used to pull the seamless long rail strip into position through the seamless long rail strip traction and conveying mechanism; the long rail strip and the track material are assembled and fixed to obtain a track panel, and the reinforcement is bound; the highway layer counterweight vehicle is used for beam surface pre-pressing; the track panel is adjusted into position at one time; the concrete is pumped from the highway layer from top to bottom to pour the ballastless track; water is led from the highway layer to carry out the ballastless track soaking and maintenance; and the seamless line is welded and locked. The method is higher in efficiency, more convenient in construction, shorter in period and stronger in flexibility for the ballastless track laying of the seamless line on the highway-railway dual-purpose long-span bridge.

Description

Technical Field

[0001] This invention relates to the field of track engineering, specifically to a method for laying seamless track and ballastless track on a long-span bridge for both road and rail use. Background Technology

[0002] Road-rail bridges are crucial transportation infrastructure spanning large rivers. Early road-rail bridges primarily used ballasted track for the railway level. In recent years, seamless track ballastless track has gained increasing attention due to its advantages of high smoothness, high stability, and high durability, and has been widely adopted in high-speed railways and passenger / freight lines. However, laying seamless track ballastless track on long-span road-rail bridges still faces the following challenges:

[0003] 1. Traditional ballastless track construction generally uses a rail flatbed truck to transport rail materials to the end point of the completed ballastless track, and then transports the rail materials to the track laying work surface by laying running rails on the beam surface and erecting a small gantry crane. This has the following problems: (1) Since it relies on the completed ballastless track for rail material transportation, the track laying operation can only proceed sequentially. If there are individual sections with greater construction difficulty that require waiting for special equipment to be manufactured and transported to the site (such as the beam end expansion joint and rail expansion joint adjustment section), it cannot be skipped directly and must wait for its construction to be completed. Therefore, the construction flexibility is poor; (2) In order to prevent the ballastless track concrete from being crushed and cracked due to the premature operation of the rail flatbed truck, it is necessary to wait for the newly poured concrete to be used. After the ballastless track concrete has been fully hardened (about 3-7 days), the track flatcar can be driven. Since the ballastless track concrete has not been fully cured for 28 days, in order to prevent the concrete from being damaged by wheel-rail impact during high-speed driving, the speed of the track flatcar is generally only 5-10 km / h, so the transportation efficiency is low. (3) The dual-purpose railway and highway large-span steel truss is a closed beam structure. The track area is generally located inside the steel truss, and the clearance space is relatively narrow, making it difficult to erect a small gantry crane. Therefore, the rail material is difficult to transport to the track laying operation surface. (4) The gantry crane running rail is generally fixed to the bridge deck by expansion bolts. A large number of holes need to be drilled in the bridge deck, which seriously weakens the bearing capacity of the bridge deck and causes safety hazards.

[0004] 2. Traditional seamless track construction generally employs two schemes: Scheme 1 involves welding 100m factory-made rails into 500m long rails at a rail welding base, then using a large rail-laying machine to pull the 500m long rails into place, and finally welding them together to form a seamless track across sections; Scheme 2 involves laying 25m steel rails in place and then directly welding them together to form a seamless track. Scheme 1 requires a large rail-laying machine to pull the 500m long rails into place. Due to the limited internal space of the large-span steel truss girder for both road and rail use, and the dense pre-embedded reinforcing bars on the beam surface in the track area, it is impossible to operate a large rail-laying machine, making it difficult to implement. Scheme 2, due to the shorter rail length, results in more welding joints, making it difficult to guarantee welding quality and efficiency.

[0005] 3. To ensure navigational clearance requirements under the bridge, dual-purpose road-rail bridges generally adopt large-span steel truss structures. Due to the large span and relatively low beam stiffness, during the pouring of ballastless track concrete, the beam will continuously deflect downwards as the weight of the ballastless track concrete increases, causing the track surface elevation to constantly change. This makes it impossible to control and maintain track laying accuracy. Furthermore, because the degree of beam surface deflection differs significantly before and after ballastless track concrete pouring, "coarse adjustment" and "fine adjustment" of the track are required before and after the concrete pouring. "Fine adjustment" can only be done by adjusting the height using fasteners. Since the total height adjustment amount of the fasteners is extremely limited (generally only 2-4 cm), the "fine adjustment" during construction significantly reduces the height adjustment margin for fasteners during operation. If uneven settlement or localized upward arching deformation occurs during operation, it will be difficult to effectively adjust and restore the track elevation using fasteners, posing a potential safety hazard.

[0006] 4. Because ballastless track beds directly bear the dynamic load of railway trains, a lower slump is generally used to reduce the risk of cracking. Therefore, the concrete has poor fluidity, making it difficult to pump from under the bridge upwards. Furthermore, dual-purpose road-rail bridges are generally large river-crossing bridges, and the conditions for operating concrete transport trucks and pump trucks under these bridges are not suitable. Therefore, currently, dual-purpose road-rail bridges use hoppers to transport concrete to the track-laying work surface for pouring the ballastless track bed. However, because dual-purpose road-rail bridges cross large rivers, their main bridges and approach bridges are long, resulting in a large concrete transport distance. During hopper transport, the concrete is highly susceptible to segregation, caking, and other phenomena, leading to concrete failure.

[0007] 5. Road-rail bridges are located in open, windy environments, causing rapid moisture loss from the ballastless track concrete, which is prone to drying shrinkage and cracking. Traditional ballastless track maintenance mainly relies on manual watering, which is inefficient. Existing automatic sprinkler or drip irrigation maintenance equipment has a complex structure and often requires a power interface, making it unsuitable for the construction environment on road-rail bridges. Summary of the Invention

[0008] In order to overcome the defects existing in the prior art, the purpose of this invention is to provide a method for laying seamless track and ballastless track on a long-span bridge for both road and rail use.

[0009] To achieve the above-mentioned objectives of the present invention, the present invention provides a method for laying seamless track and ballastless track on a long-span bridge for both road and rail use, comprising the following steps:

[0010] S1. Transport the rail material to the highway layer above the track laying operation surface;

[0011] S2. Hoisting rail materials from the highway layer to the track laying operation surface;

[0012] S3. Lay the sleepers to the designed positions according to the designed sleeper spacing;

[0013] S4. Install a seamless long rail traction and transmission mechanism between the highway layer and the auxiliary rail working surface for traction of seamless long rails.

[0014] S5. Transport seamless long rails to the end point of the ballastless track that has been laid and is ready for operation;

[0015] S6. Using road-level vehicles, seamless long rails are positioned by a traction and conveying mechanism.

[0016] S7. Assemble and fix the long rails and rail materials to obtain the rail panel, and tie the reinforcing steel bars;

[0017] S8. Use road layer counterweight vehicles to preload the beam surface to compensate for the weight of the uncast ballastless track concrete in the railway layer, so that the flexural deformation of the large-span steel truss is equivalent to that after the ballastless track is cast.

[0018] S9. Adjust the track panel into place in one go;

[0019] S10. Concrete is pumped from the road layer down to pour ballastless track.

[0020] S11. Water is drawn from the highway layer for saturation and curing of ballastless track;

[0021] S12, Seamless circuit welding and locking.

[0022] This method makes the laying of seamless track and ballastless track on long-span bridges for both road and rail more efficient, easier, shorter in cycle, and more flexible.

[0023] In a preferred embodiment of the method for laying seamless track and ballastless track on the dual-purpose railway and highway long-span bridge, when hoisting rail materials from the highway level to the track laying work surface, a crane is used to hoist the rail materials from top to bottom to the height of the railway level, and then transport them to the track laying work surface through the side space of the steel truss girder.

[0024] In a preferred embodiment of the method for laying seamless track and ballastless track on a long-span bridge for both road and rail, when the sleepers are laid to the designed position according to the designed sleeper spacing, a support pad is placed under the sleeper, and the thickness of the support pad is equivalent to the thickness of the concrete under the ballastless track sleeper.

[0025] In a preferred embodiment of the seamless track and ballastless track laying method on the dual-purpose railway and highway long-span bridge, the seamless long rail traction and transmission mechanism includes a pulley assembly and a traction cable;

[0026] The pulley assembly includes several transmission pulleys arranged at intervals along the center line of the rail, and steering pulleys respectively set on the railway layer and the highway layer. The surface of the pulley is provided with a groove structure for placing traction cables and seamless long rails.

[0027] One end of the traction cable is equipped with a clamping device for holding long rails, and the other end is equipped with a hook for traction.

[0028] In a preferred embodiment of the seamless track and ballastless track laying method on the dual-purpose railway and highway long-span bridge, the track panels are fixed by adjustable supports.

[0029] The adjustable support includes a crossbeam, a longitudinal beam, a vertical beam, and a clamping device. The clamping device clamps onto the rail head to adjust the longitudinal, transverse, and vertical directions of the rail panel.

[0030] In a preferred embodiment of the seamless track and ballastless track laying method on this long-span dual-purpose railway and highway bridge, the formula for calculating the number of counterweight vehicles when using road-level counterweight vehicles for beam preloading is as follows:

[0031]

[0032] In the formula:

[0033] W g The total weight of the concrete for the ballastless track on the bridge span to be laid;

[0034] W g ′ represents the weight of the concrete ballastless track already poured on the bridge span to be laid;

[0035] W t This refers to the weight of the concrete mixer truck, which includes the vehicle's own weight and the concrete load.

[0036] n t This refers to the number of concrete mixer trucks.

[0037] W b This refers to the weight of the concrete pump truck.

[0038] n b This refers to the number of concrete pump trucks;

[0039] W p To counterbalance the weight of the vehicle;

[0040] n p The number of counterweight vehicles required for the bridge span to be laid.

[0041] In a preferred embodiment of the method for laying seamless track ballastless track on a long-span bridge for both road and rail use, when the ballastless track is soaked and cured, a water-retaining layer is covered on the ballastless track, and a water supply pipe is suspended inside the steel truss. One end of the water supply pipe extends upward to the road layer, and the other end of the water supply pipe is closed. Several spray holes are set at intervals on the water supply pipe, and the water pressure generated by the height difference between the road layer and the railway layer is used to spray the ballastless track.

[0042] In a preferred embodiment of the method for laying seamless track and ballastless track on a long-span bridge for both road and rail use, steps S8 and S9 are performed alternately until the entire beam surface is preloaded and the track panels are adjusted into place.

[0043] In a preferred embodiment of the method for laying seamless track and ballastless track on a long-span bridge for both road and rail use, step S10 involves using a concrete mixer truck to transport concrete directly from the mixing plant to the road layer above the track laying work surface, and then using a concrete pump truck to pump the concrete from top to bottom to the track laying work surface through a concrete pumping pipeline that passes through the side space of the steel truss beam.

[0044] The beneficial effects of this invention are:

[0045] 1. This invention utilizes the road level of a dual-purpose road-rail bridge for rail material transportation, employs cranes operating on the road level to lift rail materials, and directly transports the rail materials to the track-laying work surface from the side through the space of the steel truss girder. This solves the problem of limited space in the internal track area of ​​a large-span steel truss girder for dual-purpose road-rail bridges, making it difficult to erect a small gantry crane for track laying. Furthermore, it eliminates the need for pre-constructed ballastless track for rail material transportation, allowing direct transport of rail materials to the track-laying work surface via vehicles on the road level. This flexibly bypasses construction points that are difficult to construct or temporarily lack the necessary conditions, significantly improving the efficiency and flexibility of track-laying operations. Additionally, in some scenarios, dual-purpose road-rail bridges require the installation of an integrated "beam end expansion joint and rail expansion adjuster" at each span of the bridge beam. Traditional rail material transportation methods require… The rail material can only be transported to the next bridge section for ballastless track construction after the integrated beam-end expansion joint and rail expansion adjuster have arrived on site. Since the production and transportation cycle of the integrated beam-end expansion joint and rail expansion adjuster is long, potentially up to six months if overseas transportation is involved, this can easily cause project delays. However, this invention eliminates the need to wait for the integrated beam-end expansion joint and rail expansion adjuster to arrive, allowing the rail material to be transported directly to the next bridge section via the road layer for ballastless track construction, thus saving track laying time.

[0046] 2. This invention utilizes road-level vehicles and pulley assemblies to haul 100m of factory-made seamless long rails into place. After the ballastless track is laid, the 100m long rails are directly welded into seamless track for cross-section sections. Compared with the traditional method of directly laying 500m seamless long rails, this invention solves the problem of limited space in the internal track area of ​​large-span steel truss girders for both road and rail use, making it difficult to operate large-scale track-laying units for seamless long rails. Compared with the traditional method of welding seamless track with 25m standard rails, the number of welding joints is only 1 / 4, significantly improving the quality and efficiency of rail welding.

[0047] 3. This invention utilizes road-level vehicles for preloading the beam surface, followed by a one-time fine-tuning of the track panel. This solves the problem of inconsistent beam surface deflection before and after ballastless track concrete pouring in long-span bridges, which makes it difficult to guarantee the final track elevation construction accuracy. Using vehicles as preloading loads is convenient and flexible; the preloading load can be dynamically adjusted by changing the number of preloading vehicles, ensuring the accuracy of the preloading load. Through beam surface preloading, the beam surface reaches the deflection level expected after ballastless track construction before the concrete pouring and during track panel adjustment. This eliminates the need for separate "coarse" and "fine" adjustments before and after concrete pouring, achieving a one-time adjustment of the track panel. This significantly simplifies the track laying process, improves track laying efficiency, and provides more allowance for fastener height adjustment during subsequent operation.

[0048] 4. This invention utilizes the highway layer for concrete transportation and "top-down" pumping for pouring the ballastless track bed. Utilizing the highway layer for concrete transportation solves the problems of long-distance concrete transport and concrete clumping during hopper transport on long-span dual-purpose road-rail bridges. Using concrete pump trucks operating on the highway layer to pump concrete "top-down" to the railway layer's ballastless track working surface solves the problem of pumping low-slump ballastless track concrete "bottom-up" onto the bridge. Simultaneously, during the ballastless track concrete pouring process, the concrete only transfers from the highway layer to the railway layer, maintaining a constant load across the entire bridge span. This avoids continuous deflection of large-span bridges during ballastless track concrete pouring, ensuring track laying accuracy.

[0049] 5. This invention utilizes the water head pressure created by the height difference between the highway layer and the railway layer for automatic spraying and immersion curing. Water is injected into the immersion curing system via a water truck operating on the highway layer, flowing into a water pipe suspended on the side of the steel truss beam. Spray nozzles are installed on the pipe to continuously spray and moisturize the water-retaining layer covering the ballastless track, achieving all-weather automated immersion curing of the ballastless track and preventing the formation of shrinkage cracks.

[0050] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0051] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0052] Figure 1 This is a flowchart illustrating the present invention;

[0053] Figure 2 This is a schematic diagram showing the transportation of rail materials from the highway level to the track-laying work surface;

[0054] Figure 3This is a schematic diagram of rail materials being hoisted from top to bottom on the highway level.

[0055] Figure 4 This is a schematic diagram showing the arrangement of sleepers according to the designed spacing;

[0056] Figure 5 This is a schematic diagram of the traction and transmission mechanism for long rails on a seamless railway line.

[0057] Figure 6 This is a schematic diagram of using vehicles on the highway level for preloading the beam surface;

[0058] Figure 7 This is a schematic diagram of pumping concrete from the top of the road layer to pour ballastless track.

[0059] Figure 8 This is a schematic diagram of water diversion from the highway layer for ballastless track immersion and curing.

[0060] Figure 9 This is a schematic diagram of the adjustable bracket;

[0061] Figure 10 This is a top-view diagram of the adjustable bracket fixing the track.

[0062] Among them: 1 is the steel truss girder of the dual-purpose road-rail bridge; 101 is the railway level of the dual-purpose road-rail bridge; 102 is the highway level of the dual-purpose road-rail bridge; 2 is the laid ballastless track; 3 is the track laying work surface; 401 is a freight truck; 402 is a crane; 403 is a tractor; 404 is a concrete mixer truck; 405 is a concrete pump truck; 406 is a counterweight vehicle; 407 is a water truck; 5 is rail material; 6 is rail. 7 is a sleeper, 8 is a seamless long rail, 901 is a transmission pulley, 902 is a steering pulley, 903 is a traction cable, 10 is a rail panel that has been assembled but has not yet been poured with ballastless track concrete, 11 is a concrete pumping pipe, 12 is a newly laid ballastless track, 13 is a water supply pipe, 1301 is a sprinkler hole, 141 is a crossbeam, 142 is a longitudinal beam, 143 is a vertical beam, and 144 is a clamping device. Detailed Implementation

[0063] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0064] In the description of this invention, unless otherwise specified and limited, it should be noted that the terms "installation", "connection" and "linking" should be interpreted broadly. For example, they can refer to mechanical or electrical connections, or internal connections between two components. They can be direct connections or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0065] like Figure 1 As shown, this invention provides an embodiment of a method for laying seamless track and ballastless track on a long-span road-rail bridge. This embodiment is illustrated using the Padma Bridge in Bangladesh as an example.

[0066] The Padma Bridge in Bangladesh has a main span of 6.15 km, consisting of six 900m long continuous steel truss girder sections and one 750m long continuous steel truss girder section. The substructure piers are spaced 150m apart. The upper level of the steel truss girder is the road level (102), and the lower level is the railway level (101), with seamless track and ballastless rails laid on the railway level (101). Approach bridges are located at both ends of the main bridge: a 2.836km long railway approach bridge on the north side and a 4.292km long railway approach bridge on the south side, for a total length of 13.278km (main bridge + approach bridges).

[0067] When laying seamless track and ballastless track, the specific steps are as follows:

[0068] S1. Transport the rail material 5 to the highway layer 102 above the track laying work surface 3. During the transport of the rail material 5, a truck 401 is used to transport the fasteners, sleepers 6, reinforcing bars, and other rail materials 5 to the highway layer 102 above the track laying work surface 3. Figure 2 As shown, taking the middle section of the "main bridge + approach bridge" as an example, the rail material transportation distance is 13.278 / 2 = 6.639 km. On highways, the speed of vehicles can reach 60 km / h, so transporting 6.639 km takes approximately 0.11 hours, or 7 minutes. In contrast, the traditional rail material transportation method (using newly constructed ballastless track 12 with rail flatcars) requires a slower rail flatcar speed of approximately 10 km / h to avoid impact cracking of the newly constructed concrete due to high-speed travel. Transporting 6.639 km takes approximately 0.66 hours, or 40 minutes. In comparison, the rail material transportation time in this embodiment is only 17.5% of the traditional method. Furthermore, unlike the traditional construction method, it does not require waiting for all the ballastless track concrete to fully harden (3-7 days after concrete pouring) before using the rail flatcars; this embodiment does not have this limitation. This embodiment can directly transport rail material 5 to the actual track laying location, making it more convenient and faster.

[0069] S2. Rail material 5 is hoisted from the highway level 102 to the track-laying work surface 3. On the highway level 102 above the track-laying work surface 3, a crane 402 is used to hoist materials such as sleepers 6, fasteners, and reinforcing bars from top to bottom to the height of the railway level 101. Then, these materials are transported to the track-laying work surface 3 through the side space of the steel truss beam. Figure 3 As shown.

[0070] S3. Lay the sleepers 6 to their designed positions according to the designed sleeper spacing. Specifically, according to the design drawings, place the sleepers 6 to their designed positions according to the designed sleeper spacing. Place support blocks 7 under the sleepers 6. The thickness of the support blocks 7 is approximately the same as the thickness of the concrete under the ballastless track sleepers to ensure that the sleepers 6 are roughly at the designed elevation. Figure 4 As shown.

[0071] S4. A seamless long rail traction and conveying mechanism for pulling seamless long rails 8 is installed between the highway layer 102 and the auxiliary rail working surface. This seamless long rail traction and conveying mechanism consists of a pulley assembly and a traction cable 903. Its purpose is to use the traction vehicle 403 of the highway layer 102 to pull the seamless long rails 8 of the railway layer 101 into position, solving the problem that the narrow space and pre-embedded steel bars on the beam surface of the railway layer 101 make mechanized laying of seamless long rails 8 impossible. The pulley assembly consists of several conveying pulleys 901 arranged at 5-10m intervals along the centerline of the rails, and steering pulleys 902 respectively installed on the railway layer 101 and the highway layer 102. Figure 5 As shown. The pulley surface has a grooved structure to facilitate the placement of the seamless long rail 8 and the traction cable 903. One end of the traction cable 903 is equipped with a clamping device for clamping the seamless long rail 8. This clamping device can adopt a conventional structure. The other end is equipped with a hook for easy fixation to the towing vehicle.

[0072] S5. Transport 100m of factory-made seamless long rail 8 to the end point of the already laid ballastless track 2 using a rail flatbed cart. At this point, the already laid ballastless track 2 should be ready for operation. Ready for operation means that the concrete pouring has been completed and hardened, such as 3-7 days after the concrete pouring. Specifically, using the already laid ballastless track 2, transport the seamless long rail 8 to the end point of the already laid ballastless track 2 via a rail flatbed cart for use at the track laying work surface 3. The track laying work surface is the area where track laying is currently underway.

[0073] S6. Using the vehicle on the highway level 102, a 100m seamless long rail 8 is towed into position via a seamless long rail traction and conveying mechanism. Specifically, one end of the traction cable 903 is clamped to the end of the seamless long rail 8, and the other end is fixed to the traction vehicle on the highway level 102. The traction force of the vehicle is used to pull the seamless long rail 8 into position. Figure 5 As shown.

[0074] S7. On the track-laying work surface 3, assemble and fix the seamless long rails 8 and rail materials 5 to obtain the track panel, and tie the reinforcing bars. Specifically, after the seamless long rails 8 are in place, assemble the seamless long rails 8, fasteners, and sleepers 6 into the track panel structure. Fix the track panel with adjustable brackets and remove the support pads 7 under the sleepers 6.

[0075] like Figure 9 and Figure 10 As shown, the adjustable bracket consists of a crossbeam 141, a longitudinal beam 142, a vertical beam 143, and a clamping device 144. The crossbeam 141 is aligned with the sleeper 6, and the longitudinal beam 142 is aligned with the seamless long rail 8. The crossbeam 141 and the longitudinal beam 142 are perpendicular to each other. The vertical beam 143 passes vertically through the crossbeam 141 and is fixed to the bridge deck. The clamping device 144 is mounted on the longitudinal beam 142 and clamps the rail head of the seamless long rail 8, enabling longitudinal, transverse, and vertical adjustments to the rail section.

[0076] S8. Preloading the beam surface is performed on the highway layer 102 using counterweight vehicles 406. Specifically, counterweight vehicles 406 (such as dump trucks, freight trucks 401, etc.) are used on the highway layer 102, together with concrete mixer trucks 404, to preload the beam surface to compensate for the weight of the uncast ballastless track concrete on the bridge, ensuring that the deflection deformation of the large-span steel truss girder is equivalent to that after the ballastless track is cast. This avoids continuous downward deflection of the beam surface during the ballastless track casting process, which could affect the track laying accuracy. Figure 6 As shown.

[0077] When using counterweight vehicles 406 in highway layer 102 for beam preloading, the formula for calculating the number of counterweight vehicles 406 is as follows:

[0078]

[0079] In the formula:

[0080] W g The total weight of the concrete for the ballastless track on the bridge span to be laid;

[0081] W g ′ represents the weight of the concrete ballastless track already poured on the bridge span to be laid;

[0082] W t The weight of the 404 concrete mixer truck includes the vehicle's own weight and the concrete load.

[0083] n t The quantity of 404 concrete mixer trucks;

[0084] W b The weight of the concrete pump truck is 405.

[0085] n bThis refers to the quantity of concrete pump truck 405;

[0086] W p To counterbalance the vehicle's weight of 406;

[0087] n p The required number of counterweight vehicles is 406, which are needed for the bridge span to be laid.

[0088] In this embodiment, the volume of concrete for the ballastless track on every 150m bridge span is approximately 126.45m. 3 Its weight is 3098 kN. Concrete mixer truck 404 (fully loaded approximately 12m³) 3 The concrete mixer truck (404) weighs 30 tons, with a corresponding weight of 294 kN; the concrete pump truck (405) weighs 30 tons, with a corresponding weight of 294 kN; and the counterweight dump truck is fully loaded with 35 tons, with a corresponding weight of 343 kN. According to formula (1), the preloading is carried out using "1 concrete mixer truck (404) + 1 concrete pump truck (405) + 7 counterweight dump trucks". After all the preloading vehicles are in place, the deflection at the mid-span of the bridge is close to 15 cm, which is the same as the deflection after the ballastless track concrete is poured.

[0089] S9. Adjust the track panel into position in one go. The track panel here refers to the assembled track panel 10 that has not yet been poured with ballastless track concrete. After the vehicle preloading in step S8, the beam surface deflection has reached the state after track laying. Moreover, during the pouring of ballastless track concrete, the concrete is only transferred from the concrete mixer truck 404 on the highway layer 102 to the track area of ​​the railway layer 101. Therefore, no new load is generated on the bridge span, so the beam surface and beam body 1 will not gradually deflect as the concrete is poured. Therefore, it is only necessary to adjust the assembled track panel 10 that has not yet been poured with ballastless track concrete into position in one go, without the need for separate "coarse adjustment" and "fine adjustment" before and after the pouring of ballastless track concrete.

[0090] In this embodiment, when the first concrete mixer truck 404 contains approximately 12m³ of concrete... 3 After all the concrete was poured, the first concrete mixer truck (404) drove away from the bridge span, and the second concrete mixer truck (404) (fully loaded with approximately 12m³) arrived. 3 The concrete was driven in, and at this point, the remaining unpoured concrete volume for the ballastless track on the bridge was 126.45 - 12 = 114.45 m³. 3 Then, according to formula (1), the preloading can be done by using "1 concrete mixer truck 404 + 1 concrete pump truck 405 + 6 counterweight dump trucks". That is, one of the counterweight dump trucks that was originally parked on the bridge span (preferably the counterweight dump truck on the highway layer 102 above the already poured ballastless track) is required to leave the bridge span, and then the next section of track is adjusted, and the second truck of concrete is poured. This process continues until the entire beam surface is preloaded and the track is adjusted to the correct position.

[0091] S10. Concrete is pumped from top to bottom from the highway layer 102 to pour the ballastless track, forming the newly laid ballastless track 12. Specifically, a concrete mixer truck 404 transports concrete directly from the mixing plant to the highway layer 102 above the track laying work surface 3. A concrete pump truck 405 pumps the concrete from top to bottom to the track laying work surface 3 through a concrete pumping pipe 11 that passes through the side space of the steel truss beam 1. Figure 7 As shown. Because a top-down pumping method is used, the requirements for concrete fluidity are lower, enabling the pumping of low-slump ballastless track concrete. During the pouring process, since the concrete is simply transferred from the concrete mixer truck 404 on the highway layer 102 to the ballastless track on the railway layer 101, the total weight on the bridge remains constant, therefore the beam surface does not change. The newly laid ballastless track 12 after construction has high precision.

[0092] S11. Water is drawn from the highway layer 102 for immersion curing of the ballastless track. During curing, a ballastless track immersion curing system is used. This system includes 13 water pipes suspended inside the steel truss beams and a water-retaining layer covering the ballastless track. One end of the water pipe 13 extends upwards to the highway layer 102, where a water truck 407 injects curing water. The other end of the water pipe 13 is closed. Spray holes 1301 are installed at regular intervals along the water pipe 13, utilizing the head pressure generated by the height difference between the highway layer 102 and the railway layer 101 to achieve spraying. The water-retaining layer is composed of hydrophilic fabrics, such as geotextiles or sponges. Under the continuous spraying action of the water pipe 13, the water-retaining layer remains moist, providing moisture retention and curing for the newly laid ballastless track 12 concrete. Figure 8 As shown.

[0093] S12. Seamless Track Welding and Locking. In this embodiment, under the designed rail temperature conditions, 100m factory-made seamless long rails 8 are welded into seamless track spanning multiple sections. Since 100m factory-made seamless long rails 8 are used directly instead of 25m standard rails, no replacement is required, and the number of rail welding joints is relatively small, significantly improving construction quality and track smoothness. Due to the fewer welding joints, both commonly used flash welding and more flexible aluminothermic welding, which does not require dedicated rail welding vehicles and equipment, can be used, fully adapting to the working environment inside the track area of ​​large-span steel trusses. In this embodiment, the number of welding joints is 6150 / 100*2 = 123, only 1 / 4 of that of the traditional method.

[0094] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0095] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A method for laying seamless track and ballastless track on a long-span bridge for both road and rail use, characterized in that, Includes the following steps: S1. Transport the rail material to the highway layer above the track laying operation surface; S2. Hoisting rail materials from the highway layer to the track laying operation surface; S3. Lay the sleepers to the designed positions according to the designed sleeper spacing; S4. Install a seamless long rail traction and transmission mechanism between the highway layer and the track laying operation surface for traction of seamless long rails; S5. Transport seamless long rails to the end point of the ballastless track that has been laid and is ready for operation; S6. Using road-level vehicles, seamless long rails are positioned by a traction and conveying mechanism. S7. Assemble and fix the long rails and rail materials to obtain the rail panel, and tie the reinforcing steel bars; S8. Use road layer counterweight vehicles to preload the beam surface to compensate for the weight of the uncast ballastless track concrete in the railway layer, so that the flexural deformation of the large-span steel truss is equivalent to that after the ballastless track is cast. S9. The track panel can be adjusted into place in one go, eliminating the need for separate "coarse" and "fine" adjustments before and after the ballastless track concrete pouring. S10. Concrete is pumped from the road layer down to pour the ballastless track. S11. Water is drawn from the highway layer for saturation and curing of ballastless track; S12, Seamless circuit welding and locking; When hoisting rail materials from the highway level to the track laying work surface, a crane is used to hoist the rail materials from top to bottom to the height of the railway level, and then transport them to the track laying work surface through the side space of the steel truss beam; The seamless long rail traction and transmission mechanism includes a pulley assembly and a traction cable; The pulley assembly includes several conveying pulleys arranged at intervals along the center line of the rail, and steering pulleys respectively set on the railway layer and the highway layer. The surfaces of the conveying pulleys and the steering pulleys are provided with groove-shaped structures for placing traction cables and seamless long rails. One end of the traction cable is equipped with a clamping device for holding long rails, and the other end is equipped with a hook for traction.

2. The method for laying seamless track and ballastless track on a long-span dual-purpose railway and highway bridge according to claim 1, characterized in that, When laying the sleepers to the designed positions according to the designed sleeper spacing, support blocks are placed under the sleepers, and the thickness of the support blocks is equivalent to the thickness of the concrete under the ballastless track sleepers.

3. The method for laying seamless track and ballastless track on a long-span dual-purpose railway and highway bridge according to claim 1, characterized in that, When fixing the track panel, use adjustable brackets for fixation; The adjustable support includes a crossbeam, a longitudinal beam, a vertical beam, and a clamping device, which clamps onto the rail head.

4. The method for laying seamless track and ballastless track on a long-span dual-purpose railway and highway bridge according to claim 1, characterized in that, When using roadbed counterweight vehicles for beam preloading, the formula for calculating the number of counterweight vehicles is: ； In the formula: The total weight of the concrete for the ballastless track on the bridge span to be laid; The weight of the already poured ballastless track concrete on the bridge span to be laid; This refers to the weight of the concrete mixer truck, which includes the vehicle's own weight and the concrete load. This refers to the number of concrete mixer trucks. This refers to the weight of the concrete pump truck. This refers to the number of concrete pump trucks; To counterbalance the weight of the vehicle; The number of counterweight vehicles required for the bridge span to be laid.

5. The method for laying seamless track and ballastless track on a long-span dual-purpose railway and highway bridge according to claim 1, characterized in that, When performing immersion curing on ballastless track, a water-retaining layer is covered on the ballastless track, and a water supply pipe is suspended inside the steel truss. One end of the water supply pipe extends upward to the road layer, and the other end of the water supply pipe is closed. Several spray holes are set at intervals on the water supply pipe, and the water pressure generated by the height difference between the road layer and the railway layer is used to spray the ballastless track.

6. The method for laying seamless track and ballastless track on a long-span dual-purpose railway and highway bridge according to claim 1, characterized in that, Step S10 involves using a concrete mixer truck to transport concrete directly from the mixing plant to the road layer above the track laying work surface, and then using a concrete pump truck to pump the concrete from top to bottom through a concrete pumping pipe that passes through the side space of the steel truss beam.

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