High-speed railway roadbed pipe culvert integrated construction method

Abstract

The invention relates to a high-speed railway subgrade pipe culvert integrated construction method which comprises the following steps: installing temporary limiting piers and working pits at a high-speed railway subgrade to support a track structure; jacking equipment is adopted for jacking cross beams, hoisting longitudinal beams and connecting the longitudinal beams with the cross beams to form a longitudinal and transverse beam system, the cross beams are arranged below a base plate of the ballastless track and make contact with a roadbed soil body, the longitudinal beams are arranged at the two ends of each cross beam respectively and supported on auxiliary beam buttresses, and the longitudinal and transverse beam system forms elastic support; a plurality of pipe joints are jacked in a segmented mode, reserved hole channels are formed in the pipe joints, and the pipe joints are tensioned through transversely-penetrating prestressed steel strands to form an integrally-stressed pipe culvert structure; the MJS construction method is adopted to reinforce the bottom foundation of the pipe culvert structure through the reserved hole channel; and after construction of the pipe culvert structure is completed, the supports are dismantled, and line operation is recovered. The method has the advantages that interference of construction on railway operation is reduced, safe underpass of the high-speed railway subgrade under the shallow soil covering condition is achieved, and track deformation is effectively controlled.

Description

Technical Field

[0001] The present invention relates to the technical field of high-speed railway roadbed engineering construction, and specifically to a high-speed railway roadbed pipe culvert integrated construction method, in particular to a construction method for a pipe culvert jacking construction scenario applied under shallow covering conditions and suitable for underpasses of a high-speed railway roadbed. Background Art

[0002] At present, when constructing a pipe culvert under a high-speed railway subgrade under shallow soil cover, the existing construction methods mainly include the following categories: 1) Shield method: It requires deep burial construction (usually >20m), which makes it difficult to avoid roadbed reinforcement piles. It has high investment and long cycle, and is not suitable for shallow cover (<5m).

[0003] 2) Pipe jacking method: The cross-sectional size is limited, and a large working pit and stable backrest are required. The construction efficiency is low and the disturbance to the track structure is relatively large.

[0004] 3) Open-cut method: This method requires interrupting railway operations, significantly impacts roadbed stability, and is difficult to meet the deformation control requirements of high-speed railways (post-construction settlement ≤ 15 mm).

[0005] 4) Pipe-curtain method: requires multiple pilot tunnel excavations, complex procedures, many temporary supports, and low construction efficiency.

[0006] Generally speaking, under shallow overburden (2.5-5m), construction disturbances to high-speed railway ballastless tracks are difficult to control. Existing technologies struggle to meet the demands of large cross-sections, low disturbance, and rapid construction. Summary of the Invention

[0007] The purpose of the present invention is to provide a high-speed railway roadbed pipe culvert integrated construction method based on the above-mentioned deficiencies of the existing technology. The method adopts the "rigid temporary beam support method" as the core, combines small-section jacking technology, prestressed steel strand transverse tensioning and rapid-setting concrete filling technology to form an integrated pipe culvert construction system, reduce the interference of construction on railway operations, realize the safe underpass of high-speed railway roadbed under shallow covering conditions, and effectively control track deformation.

[0008] The purpose of the present invention is achieved by the following technical solutions: A method for constructing a high-speed railway roadbed and culvert integrated with a ballastless track structure is provided on the high-speed railway roadbed, characterized in that it comprises the following steps: Installing temporary limit piers and working pits at the high-speed railway roadbed to support the track structure; A jacking device is used to jack the crossbeam, and the longitudinal beam is hoisted and connected to the crossbeam to form a longitudinal and transverse beam system. The crossbeam is arranged under the base plate of the ballastless track and in contact with the roadbed soil. The longitudinal beams are respectively arranged at both ends of the crossbeam. The longitudinal beams are supported on the temporary beam piers, and the longitudinal and transverse beam system forms an elastic support. Several pipe sections are jacked in sections, each of which has a reserved channel, and the pipe sections are tensioned by the cross-threaded prestressed steel strands to form an integrally stressed pipe culvert structure; The bottom foundation of the pipe culvert structure is reinforced through the reserved channel using the MJS method; After the construction of the pipe culvert structure is completed, the support is removed and the line operation is resumed.

[0009] A temporary support structure is provided below the ballastless track structure, comprising a prefabricated base, a steel pad, an H-shaped steel support, a track-dropping device and a composite pad, wherein the prefabricated base is provided on the surface of the base bed, the H-shaped steel support is provided on the prefabricated base through the steel pad, the track-dropping device is provided on the H-shaped steel support, and the composite pad is provided between the ballastless track structure and the track-dropping device.

[0010] The pipe section includes a standard pipe section and a tool pipe section. The tool pipe section is arranged at a corner of the standard pipe section. The standard pipe section and the tool pipe section are connected by an anchor piece to form an integral structure.

[0011] Post-casting construction is carried out inside the pipe segment to form an inner lining top plate, an inner lining bottom plate and an inner lining side wall.

[0012] Along the extending direction of the longitudinal beams, a plurality of transverse beams are evenly spaced and arranged between the longitudinal beams on both sides; concrete is poured between adjacent transverse beams so that the plurality of transverse beams form a combined skeleton.

[0013] An adjustable pad is provided between the cross beam and the base plate of the ballastless track.

[0014] Optical fiber displacement sensors are arranged at the node positions of the cross beam and the longitudinal beam.

[0015] The advantages of the present invention are: 1) Construction effect: (1) Precise deformation control: Track deformation ≤2.0mm: Through the elastic foundation beam design of the rigid temporary beam support system (double-jointed I-beam crossbeam + steel box longitudinal beam), the track structure displacement during the construction period is strictly controlled within 2.0mm, meeting the allowable deviation limit of dynamic unevenness of high-speed railways (high and low unevenness ≤0.05mm / m).

[0016] Roadbed settlement ≤ 5mm: Prestressed pipe segment transverse tensioning technology (19 strands of steel wire, tensioning force ≥ 150kN) is used to form an integral load-bearing structure, effectively dispersing the load. Combined with the MJS method for foundation reinforcement, the post-construction roadbed settlement is ensured to be ≤ 5mm.

[0017] (2) Efficient construction: Skylight period operation: Utilize the railway skylight period (4-6 hours / time) to quickly complete the pipe segment jacking and support installation. A single operation can advance a 2m pipe segment, which is 40% more efficient than the traditional shield method.

[0018] No need for large working pits: Through small-section pipe jacking technology (pipe section size 1m×1.4m) and modular equipment, earth excavation volume is reduced by 80% and construction area is reduced by 60%.

[0019] (3) Wide applicability: Adaptability to shallow cover: Suitable for shallow underpass scenarios with a cover thickness of 2.5-5m (traditional shield tunneling requires a burial depth greater than 20m), especially suitable for densely populated urban areas or where existing roadbed reinforcement piles are needed to avoid them.

[0020] Multi-scenario application: It can be flexibly used in interchange projects, culvert projects (diameter 1-4m), integrated pipeline corridors, etc., with a maximum cross-sectional span of up to 9m×8m.

[0021] 2) Economic benefits: (1) Cost savings: Material reuse rate > 90%: Rigid longitudinal temporary beams (I-beams, steel box beams) and prestressed pipe sections (square steel pipes) are all modularly designed. The longitudinal steel box beam temporary beams can be disassembled and reused, reducing equipment amortization costs by 50%.

[0022] The overall construction cost is reduced by 30%: Compared with the shield method, there is no need to purchase shield machines (the cost of a single machine is about 120 million yuan) and deep burial construction, and the total project investment is reduced by 30-40%.

[0023] (2) Shortened construction period: Construction period shortened by 50%: Through continuous operation during the skylight period and temporary support-free technology, the construction period of a typical project (such as a 72m pipe culvert) was shortened from the traditional 12 months to 6 months.

[0024] 3) Security and reliability: (1) Operational security assurance: Real-time monitoring system: Integrates fiber optic sensors and displacement sensors to monitor track deformation and pipe stress around the clock. Data is synchronized to the railway dispatching center to ensure that the abnormal warning response time is less than 10 minutes.

[0025] Redundant design: The pipe joint lock is filled with double-layer sealing grease (pressure resistance ≥ 0.5MPa), with an anti-leakage grade of IP68, to prevent groundwater infiltration from causing roadbed softening.

[0026] (2) Structural durability: Fatigue life ≥ 100 years: The prestressed pipe segment adopts a composite structure of Q345qE steel and C50 concrete, which increases the fatigue strength by 2 times, and the corrosion-resistant coating (epoxy resin + zinc-aluminum coating) ensures 50 years of maintenance-free.

[0027] 4) Environmental protection and sustainability: (1) Low environmental disturbance: Zero waste soil transportation: The underground excavated soil is directly backfilled to the bottom of the roadbed through the transportation channel inside the pipe section, reducing the amount of soil transported outside by 100% and reducing dust and noise pollution.

[0028] Energy consumption reduced by 40%: Compared with shield machines (power > 2000kW), the combination of small pipe jacking machines (power < 500kW) and manual underground excavation reduces overall energy consumption by 40%.

[0029] (2) Application of green materials: Quick-setting concrete: Using low-carbon concrete with an industrial solid waste (fly ash, slag) content of ≥30% can reduce carbon emissions by 25%.

[0030] Recyclable steel: The supporting system steel is 100% recyclable, in line with the requirements of the circular economy. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a plan layout diagram of the present invention; Figure 2 It is a cross-sectional layout diagram of the present invention; Figure 3 Schematic diagram of the prestressed pipe segment structure in the present invention; Figure 4 It is a cross-sectional view of the limiting pier in the present invention; Figure 5 This is a layout diagram of the temporary support structure in the present invention; Figure 6 This is a layout diagram for pouring quick-setting concrete between the beams in the present invention. DETAILED DESCRIPTION

[0032] The features of the present invention and other related features are further described in detail below through embodiments in conjunction with the accompanying drawings to facilitate understanding by those skilled in the art: like Figure 1-6As shown, numbers 1-28 in the figure respectively represent: double-jointed I-beam crossbeam 1, steel box longitudinal beam 2, temporary beam pier 3, track plate 4, base plate 5, node bolt 6, contact network foundation 7, contact network 8, filler layer 9, standard pipe section 10, limit pier 11, C60 quick-setting concrete 12, rail 13, fastener 14, self-compacting concrete 15, base bed surface layer 16, base bed bottom layer 17, tool pipe section 18, anchor 19, prestressed steel strand 20, post-cast lining top plate 21, post-cast lining bottom plate 22, post-cast lining side wall 23, precast base 24, steel pad 25, H-shaped steel support 26, drop device 27, composite pad 28.

[0033] Example: Figures 1 to 6 As shown, the longitudinal and transverse beam system for supporting the ballastless track of a high-speed railway subgrade in this embodiment is applicable to the construction of a pipe culvert under a high-speed railway subgrade. The high-speed railway subgrade includes a filler layer 9, above which a subgrade bottom layer 17 is provided.

[0034] The ballastless track system consists of a base plate 5 mounted on a subgrade surface 16 and a track slab 4 above the base plate 5. Self-compacting concrete 15 is placed between the track slab 4 and the base plate 5. Rails 13 are mounted on the track slab 4 via fasteners 14. A catenary foundation 7 is also installed at the high-speed railway subgrade, on which a catenary 8 for powering the high-speed railway is installed.

[0035] Specifically, the construction of the longitudinal and transverse beam system in this embodiment includes the following steps: 1) Preparation of temporary beams: During the window period, C40 quick-setting concrete is used to cast L-shaped limit piers 11 on both sides of the line. The limit piers 11 limit the base plate 5 through a limiting device, thereby limiting the lateral displacement of the rails 13 and preventing the line from being adversely affected by the construction.

[0036] In this embodiment, a temporary support structure is also provided beneath the base plate 5 of the ballastless track. This temporary support structure includes a prefabricated base 24, a steel backing plate 25, an H-shaped steel support 26, a track-dropping device 27, and a composite backing plate 28. The prefabricated base 24 is mounted on the subgrade surface 16, the H-shaped steel 26 is supported on the prefabricated base 24 via the steel backing plate 25, the track-dropping device 27 is mounted on the H-shaped steel support 26, and the composite backing plate 28 is positioned between the base plate 5 and the track-dropping device 27. This temporary support structure limits the vertical position of the ballastless track.

[0037] 2) Erection of temporary beams: Using hydraulic jacking equipment, several double-jointed I-beams (1) are pushed one by one beneath the base plate (5) and across the line. Along the horizontal direction of the line, the spacing between adjacent double-jointed I-beams (1) is 1 meter. Adjustable pads are installed between the double-jointed I-beams (1) and the base plate (5). C60 quick-setting concrete (12) is poured between each double-jointed I-beam (1) to form a composite skeleton.

[0038] In this embodiment, the bottom of the double-jointed I-steel crossbeam 1 is in direct contact with the roadbed soil, and the load is shared by the elastic reaction force of the soil, with the maximum displacement being ≤1.5mm.

[0039] The steel box longitudinal beam 2 is prefabricated in the factory and then installed on-site. The beam 2 is hoisted integrally, and both ends of the beam 1 are placed on prefabricated temporary beam support piers 3, the bottoms of which are covered with a gravel cushion. Node bolts 6 connect the steel box longitudinal beam 2 to the double-jointed I-beam crossbeam 1. Stiffening ribs 10 are welded at the joints to enhance the connection between the two.

[0040] In this embodiment, the steel box longitudinal beam 2 can be prefabricated in sections (each section is 4 meters long) and assembled on site by hoisting and bolting. The single installation time is ≤ 2 hours.

[0041] 3) Jacking pipe section: Prefabricated square tube sections (1m / section) are jacked in sections, and sealing grease is filled into the lock buckle inside the anchor 19. Corrugated pipes and steel strands are passed through the square tube sections horizontally and symmetrically tensioned to the design stress.

[0042] In this embodiment, the square tube segment includes a standard tube segment 10 and a tool tube segment 18 . The tool tube segment 18 is disposed at a corner of the standard tube segment 10 . The standard tube segment 10 and the tool tube segment 18 are connected by an anchor 19 to form an integral structure.

[0043] Post-casting construction is carried out inside the pipe segment to form a post-cast lining top plate 21, a post-cast lining bottom plate 22, and a post-cast lining side wall 23. After the post-casting is completed, various structures for the designed purpose can be constructed inside the pipe culvert structure.

[0044] 4) Foundation reinforcement: The MJS method is used to reinforce the foundation (pile diameter 0.8m, spacing 2m) through the reserved holes on the square tube joints.

[0045] 5) Demolition and recycling: After the jacking construction of the pipe culvert under the high-speed railway subgrade is completed, the node bolts 6 are removed, the steel box longitudinal beam 2 and the temporary support device for the ballastless track structure are lifted off, and the site is cleaned; after completion, the line operation is resumed.

[0046] During the specific implementation of this embodiment: the double-jointed I-beam crossbeam 1 adopts double-jointed 36C I-beams (Q370qE material), with a length of 8.9m and a horizontal spacing of 1m, and an adjustable pad (thickness 10-30mm) is set between the rail base plate.

[0047] The steel box longitudinal beam 2 is made of steel box beam (Q345qE material), with a span of 16m and a cross-sectional size of 0.55m×0.9m. Transverse diaphragms (spacing 1m) are set inside to enhance rigidity.

[0048] The square tube section (flange thickness 25mm, web thickness 16mm) is transversely penetrated by prestressed steel strands and tensioned to form an integral load-bearing structure.

[0049] The node bolts 6 are connected with high-strength bolts (grade 10.9), and stiffening ribs 10 (20 mm thick) are provided at the nodes to ensure uniform force transmission.

[0050] Fiber optic displacement sensors are placed at the nodes between the double-jointed I-beam crossbeam 1 and the steel box longitudinal beam 2. These sensors collect the displacement changes between the two to monitor the condition of the longitudinal and transverse beam systems. During use, this data can be connected to a monitoring platform, which generates alarms when abnormal displacement exceeds the limit, ensuring construction safety.

[0051] This embodiment, through its elastic foundation design, modular rapid assembly and disassembly, and integrated intelligent monitoring technology, comprehensively improves the high-speed railway ballastless track support system in terms of deformation control, construction efficiency, economy, and environmental performance. Its core advantage lies in transforming traditional rigid support into an intelligent system that combines rigidity and flexibility. This system provides an efficient, safe, and sustainable solution for shallow underpass projects, demonstrating significant technological advancement and market competitiveness.

[0052] Although the above embodiments have described in detail the concepts and embodiments of the present invention with reference to the accompanying drawings, ordinary technicians in this field can recognize that various improvements and modifications can still be made to the present invention without departing from the scope of the claims, so they are not described in detail here.

Claims

1. A method for constructing a high-speed railway roadbed and culvert integrated with a ballastless track structure, wherein: The steps include: Installing temporary limit piers and working pits at the high-speed railway roadbed to support the track structure; A jacking device is used to jack the crossbeam, and the longitudinal beam is hoisted and connected to the crossbeam to form a longitudinal and transverse beam system. The crossbeam is arranged under the base plate of the ballastless track and in contact with the roadbed soil. The longitudinal beams are respectively arranged at both ends of the crossbeam. The longitudinal beams are supported on the temporary beam piers, and the longitudinal and transverse beam system forms an elastic support. Several pipe sections are jacked in sections, each of which has a reserved channel, and the pipe sections are tensioned by the cross-threaded prestressed steel strands to form an integrally stressed pipe culvert structure; The bottom foundation of the pipe culvert structure is reinforced through the reserved channel using the MJS method; After the construction of the pipe culvert structure is completed, the support is removed and the line operation is resumed.

2. The high-speed railway roadbed pipe culvert integrated construction method according to claim 1, characterized in that: A temporary support structure is provided below the ballastless track structure, comprising a prefabricated base, a steel pad, an H-shaped steel support, a track-dropping device and a composite pad, wherein the prefabricated base is provided on the surface of the base bed, the H-shaped steel support is provided on the prefabricated base through the steel pad, the track-dropping device is provided on the H-shaped steel support, and the composite pad is provided between the ballastless track structure and the track-dropping device.

3. The high-speed railway roadbed pipe culvert integrated construction method according to claim 1, characterized in that: The pipe section includes a standard pipe section and a tool pipe section. The tool pipe section is arranged at a corner of the standard pipe section. The standard pipe section and the tool pipe section are connected by an anchor piece to form an integral structure.

4. The high-speed railway roadbed pipe culvert integrated construction method according to claim 3, characterized in that: Post-casting construction is carried out inside the pipe segment to form an inner lining top plate, an inner lining bottom plate and an inner lining side wall.

5. The high-speed railway roadbed pipe culvert integrated construction method according to claim 1, characterized in that: Along the extending direction of the longitudinal beams, a plurality of transverse beams are evenly spaced and arranged between the longitudinal beams on both sides; concrete is poured between adjacent transverse beams so that the plurality of transverse beams form a combined skeleton.

6. The high-speed railway roadbed pipe culvert integrated construction method according to claim 1, characterized in that: An adjustable pad is provided between the cross beam and the base plate of the ballastless track.

7. The high-speed railway roadbed pipe culvert integrated construction method according to claim 1, characterized in that: Optical fiber displacement sensors are arranged at the node positions of the cross beam and the longitudinal beam.

Images