A longitudinal and transverse beam system for supporting a high-speed railway subgrade ballastless track

Abstract

This utility model relates to the field of high-speed railway subgrade engineering construction technology, specifically to a longitudinal and transverse beam system for supporting ballastless track in high-speed railway subgrades. The system includes transverse beams, longitudinal beams, and temporary beam supports. The transverse beams are positioned below the base plate of the ballastless track and in contact with the subgrade soil. Longitudinal beams are respectively installed at both ends of the transverse beams. The longitudinal beams and transverse beams are connected by bolts to form an integral structure. The longitudinal beams are supported on the temporary beam supports, and the longitudinal and transverse beam system forms an elastic support. The advantages of this utility model are: 1) Through the elastic combination design of the longitudinal and transverse beams, track displacement during construction is strictly controlled to ≤2.0mm; 2) Modular and rapid installation and disassembly of the support system are achieved, allowing for single-operation completion within the maintenance window, reducing interference with railway operations; 3) The reuse rate of the support structure is increased (>90%), reducing project costs.

Description

Technical Field

[0001] This utility model relates to the field of construction technology for high-speed railway subgrade engineering, specifically to a longitudinal and transverse beam system for supporting ballastless track in high-speed railway subgrade, and in particular to a longitudinal and transverse beam support system applicable to culvert jacking construction scenarios under shallow soil cover conditions and suitable for tunneling under high-speed railway subgrade. Background Technology

[0002] When jacking a culvert under a high-speed railway subgrade under shallow overburden conditions, a support system is needed to support the ballastless track already in use above the high-speed railway subgrade in order to ensure the operational safety of the track.

[0003] Currently, the existing support systems mainly include the following categories:

[0004] 1) Traditional rigid temporary beams: These use a single I-beam or concrete beam, which has insufficient structural rigidity and is prone to causing track displacement to exceed the standard (greater than 3mm). They also cannot adapt to the elastic deformation of shallow soil foundations.

[0005] 2) Temporary support structure: A large number of temporary supports need to be set up, the construction period is long, and the removal of them can easily cause secondary settlement, affecting the safety of railway operation.

[0006] 3) Modular support system: The existing modular support structure has complex connections and low installation efficiency, making it difficult to meet the requirements of rapid construction during the skylight period (4-6 hours / time).

[0007] In general, existing support systems struggle to balance structural stiffness and foundation elastic deformation under shallow overburden (2.5-5m) conditions, leading to failure in ballastless track displacement control. Furthermore, these systems are typically non-removable or have low reuse rates, resulting in high engineering costs. Summary of the Invention

[0008] The purpose of this invention is to address the shortcomings of the prior art by providing a longitudinal and transverse beam system for supporting ballastless track in high-speed railway subgrades. Through the combined design of longitudinal and transverse beams, and in conjunction with the stress mode of elastic foundation beams, a low-disturbance and high-stability support for the track structure during construction can be achieved.

[0009] The objective of this utility model is achieved through the following technical solution:

[0010] A longitudinal and transverse beam system for supporting ballastless track of high-speed railway subgrade is characterized in that: the longitudinal and transverse beam system includes transverse beams, longitudinal beams and temporary beam supports, the transverse beams are set under the base plate of the ballastless track and in contact with the subgrade soil, the longitudinal beams are respectively set at both ends of the transverse beams, the longitudinal beams and the transverse beams are connected by bolts to form an integral structure, the longitudinal beams are supported on the temporary beam supports, and the longitudinal and transverse beam system forms an elastic support.

[0011] Along the extension direction of the longitudinal beam, a number of crossbeams are evenly spaced between the longitudinal beams on both sides.

[0012] Concrete is poured between adjacent beams to form a composite skeleton.

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

[0014] Stiffening ribs are provided at the joints between the crossbeam and the longitudinal beam.

[0015] Fiber optic displacement sensors are arranged at the node positions of the crossbeam and the longitudinal beam.

[0016] The crossbeam is made of double-span I-beams.

[0017] The longitudinal beams are steel box beams with internal transverse diaphragms.

[0018] The longitudinal beams adopt a segmented prefabricated assembly structure.

[0019] The temporary beam support is a precast concrete support with a sand and gravel cushion layer at its bottom.

[0020] The advantages of this utility model are:

[0021] 1) System effects:

[0022] (1) Precise deformation control:

[0023] Track displacement ≤2.0mm: Through the design of elastic foundation beams with double-span I-beam crossbeams (Q370qE material) and steel box longitudinal beams (Q345qE material), the bottom of the crossbeams and the subgrade soil work together to control the vertical displacement of the track within 2.0mm and the lateral displacement within 0.8mm during construction (traditional support systems are usually 3-5mm), which is significantly better than the allowable deviation limit of dynamic irregularity of high-speed railways (height irregularity ≤0.05mm / m).

[0024] Foundation adaptability: The elastic foundation beam design allows the beam to be adjusted slightly with the elastic deformation of the soil, avoiding local stress concentration caused by rigid support. The measured soil reaction force is evenly distributed (standard deviation ≤ 10 kPa).

[0025] (2) High-efficiency construction:

[0026] Rapid installation during skylight period: The modular longitudinal beam (16m) and transverse beam (8.9m) are connected by high-strength bolts, and the support system can be installed in a single skylight period (4 hours), which improves the construction efficiency by 50% compared with traditional temporary support piers.

[0027] Weld-free process: All connections are made with bolts and hydraulic jacking, eliminating the need for on-site welding. The installation time for a single node is ≤5 minutes, reducing the risk of operation during maintenance windows.

[0028] (3) High reusability and durability:

[0029] Material reuse rate > 95%: All components of the longitudinal beams in the support system (steel box beams, bolts) can be disassembled and reused. After 10 engineering verifications, the structural performance showed no significant degradation (deformation increase ≤ 0.1mm).

[0030] Corrosion-resistant design: The longitudinal and transverse beams are coated with epoxy zinc-rich primer (thickness ≥80μm) + polyurethane topcoat (thickness ≥50μm), with a salt spray resistance test of ≥2000 hours, suitable for humid and acidic / alkaline environments.

[0031] 2) Economic benefits:

[0032] (1) Cost savings:

[0033] Equipment amortization costs reduced by 60%: Traditional temporary support systems require a one-time investment of approximately 500 tons of steel, while this system, through modular reuse, requires only 50 tons of steel per project, reducing amortization costs from 3 million yuan to 1.2 million yuan.

[0034] Labor costs reduced by 40%: The rapid disassembly and assembly process reduces labor hours, saving approximately 800,000 yuan in labor costs per project.

[0035] (2) Schedule optimization:

[0036] Construction period shortened by 50%: Taking a typical underpass project (20m culvert) as an example, the traditional support system requires 60 days, while this system only requires 30 days, reducing the railway speed limit operation time and indirectly reducing operating losses by about 5 million yuan.

[0037] 3) Safety and Reliability:

[0038] (1) Operational safety assurance:

[0039] Real-time monitoring system: Fiber optic displacement sensors (accuracy ±0.1mm) are installed at key nodes of the longitudinal and transverse beams. The data is transmitted to the monitoring platform in real time. An alarm is automatically triggered when abnormal displacement exceeds the limit (≥1.5mm), with a response time of <5 minutes.

[0040] Redundant design: stiffening ribs (1m spacing) are set inside the longitudinal beams, and quick-setting concrete (C60) is filled between the double I-beams of the crossbeams to ensure that the overall structure can still bear the design load in the event of local failure (safety factor ≥2.0).

[0041] (2) Seismic and fatigue resistance:

[0042] Seismic resistance level 8: Through finite element simulation (ANSYS), the maximum displacement of the system under a horizontal acceleration of 0.3g is ≤3mm, which meets the seismic design requirements of high-speed railway.

[0043] Fatigue life ≥ 50 years: The I-beam crossbeam underwent 2 million cycles of load testing (stress amplitude ± 50 MPa) and no cracks or plastic deformations were observed.

[0044] 4) Environmental protection and sustainability:

[0045] (1) Green construction:

[0046] Zero-waste materials: All components of the support system are recyclable, and there is no cutting or welding waste during construction, reducing construction waste by 100%.

[0047] Low-noise operation: The noise level of the hydraulic jacking and bolt connection process is ≤75dB, which is significantly lower than that of traditional welding (≥90dB) and meets the environmental protection standards for urban construction.

[0048] (2) Efficient utilization of resources:

[0049] 100% steel recycling rate: After the support system is decommissioned, the I-beams and steel box girders can be melted down and recast, reducing iron ore consumption by about 800 tons / year (based on 10 projects).

[0050] Low-carbon concrete: The quick-setting concrete filling the gaps between beams uses 30% fly ash instead of cement, reducing CO2 emissions by approximately 50 tons per project. Attached Figure Description

[0051] Figure 1 This is a plan view of the present invention;

[0052] Figure 2 This is a cross-sectional layout diagram of the present invention;

[0053] Figure 3 This is a structural diagram of the bolted connection between the longitudinal and transverse beam nodes in this utility model;

[0054] Figure 4 This is a cross-sectional view of the limiting pier in this utility model;

[0055] Figure 5 This is a diagram showing the arrangement of pouring quick-setting concrete between the crossbeams in this utility model.

[0056] Figure 6 This is a cross-sectional layout diagram of the present invention. Detailed Implementation

[0057] The features and other related features of this utility model will be further described in detail below with reference to the accompanying drawings and embodiments, so as to facilitate the understanding of those skilled in the art:

[0058] like Figure 1-6 As shown in the figure, numbers 1-17 represent: 1. Double-beam crossbeam, 2. Steel box longitudinal beam, 3. Temporary beam support, 4. Track slab, 5. Base plate, 6. Node bolt, 7. Contact wire foundation, 8. Contact wire, 9. Filling layer, 10. Stiffening rib, 11. Limiting block, 12. C60 quick-setting concrete, 13. Rail, 14. Fastener, 15. Self-compacting concrete, 16. Subgrade surface layer, 17. Subgrade bottom layer.

[0059] Example: Figures 1 to 6 As shown, the longitudinal and transverse beam system used to support the ballastless track of a high-speed railway subgrade in this embodiment is applicable to the jacking construction of culverts passing under the high-speed railway subgrade. The high-speed railway subgrade includes a fill layer 9, and a subgrade layer 17 is provided above the fill layer 9.

[0060] The ballastless track includes a base plate 5 set on the surface layer 16 of the subgrade and a track slab 4 set above the base plate 5, with self-compacting concrete 15 laid between the track slab 4 and the base plate 5. Rails 13 are installed on the track slab 4 via fasteners 14. A catenary foundation 7 is also provided at the high-speed railway subgrade, on which a catenary 8 for supplying power to the high-speed railway is installed.

[0061] Specifically, the construction of the longitudinal and transverse beam system in this embodiment includes the following steps:

[0062] 1) Install limit block 11:

[0063] During the track maintenance window, L-shaped limiting piers 11 are poured on both sides of the track using C40 quick-setting concrete. These limiting piers 11 use temporarily erected jacks to limit the base plate 5, thereby restricting the lateral displacement of the rail 13 and preventing the track from being adversely affected by the construction.

[0064] 2) Jacking in double-section I-beam crossbeam 1:

[0065] Using a hydraulic jacking device, several double-section I-beams 1 are pushed one by one under the base plate 5 and across the track. The lateral spacing between adjacent double-section I-beams 1 is 1m. Simultaneously, adjustable pads are installed between the double-section I-beams 1 and the base plate 5. C60 quick-setting concrete 12 is then poured between each double-section I-beam 1 to form a composite frame.

[0066] In this embodiment, the bottom of the double-beam crossbeam 1 is in direct contact with the subgrade soil, and the load is shared by the elastic reaction force of the soil, with a maximum displacement of ≤1.5mm.

[0067] 3) Lifting of steel box longitudinal beam 2:

[0068] The steel box girder 2 is constructed using a factory prefabrication and on-site installation method. The steel box girder 2 is hoisted as a whole, with both ends of the steel box girder 1 placed on prefabricated temporary beam supports 3. A sand and gravel cushion layer is laid at the bottom of the temporary beam supports 3. The steel box girder 2 and the double-section I-beam crossbeam 1 are connected by node bolts 6, and stiffening ribs 10 are welded at the joints to enhance the connection between them.

[0069] In this embodiment, the steel box longitudinal beam 2 can be prefabricated in sections (4m each) and assembled on site by hoisting and bolting, with a single installation time of ≤2 hours.

[0070] 4) Dismantling and Recycling:

[0071] After the culvert jacking construction under the high-speed railway subgrade is completed, the node bolts 6 are removed and the steel box longitudinal beam 2 is lifted off, and the site is cleaned up.

[0072] In this embodiment, the double-beam crossbeam 1 is made of double-beam 36C I-beams (Q370qE material), with a length of 8.9m and a lateral spacing of 1m. An adjustable pad (10-30mm thick) is set between the crossbeam and the track base plate.

[0073] The steel box longitudinal beam 2 is made of steel box girder (Q345qE material), with a span of 16m and a cross-sectional size of 0.55m×0.9m. It is equipped with transverse diaphragms (spaced 1m apart) to enhance rigidity.

[0074] The node bolts 6 are connected using high-strength bolts (grade 10.9), and stiffening ribs 10 (20mm thick) are provided at the nodes to ensure uniform force transmission.

[0075] Fiber optic displacement sensors are installed at the joint between the double-I-beam crossbeam 1 and the steel box girder 2. These sensors collect data on displacement changes between the two beams to monitor the overall condition of the beam system. During operation, this data can be connected to a monitoring platform, triggering an alarm when abnormal displacement exceeds limits, thus ensuring construction safety.

[0076] This embodiment achieves a comprehensive improvement in deformation control, construction efficiency, economy, and environmental protection of the ballastless track support system for high-speed railways through flexible foundation design, modular rapid assembly and disassembly, and further integration with intelligent monitoring technology. Its core advantage lies in transforming traditional rigid support into a "rigid-flexible synergy" intelligent system, providing an efficient, safe, and sustainable solution for shallow underpass projects, demonstrating significant technological advancement and market competitiveness.

[0077] Although the above embodiments have described the concept and embodiments of the present invention in detail with reference to the accompanying drawings, those skilled in the art will recognize that various improvements and modifications can still be made to the present invention without departing from the scope of the claims, and therefore will not be elaborated here.

Claims

1. A longitudinal and transverse beam system for supporting ballastless track in high-speed railway subgrade, characterized in that: The longitudinal and transverse beam system includes a crossbeam, longitudinal beams, and temporary beam supports. The crossbeams are set under the base plate of the ballastless track and in contact with the subgrade soil. The longitudinal beams are respectively set at both ends of the crossbeams. The longitudinal beams and the crossbeams are connected by bolts to form an integral structure. The longitudinal beams are supported on the temporary beam supports. The longitudinal and transverse beam system forms an elastic support.

2. The longitudinal and transverse beam system for supporting ballastless track of high-speed railway subgrade according to claim 1, characterized in that: Along the extension direction of the longitudinal beam, a number of crossbeams are evenly spaced between the longitudinal beams on both sides.

3. The longitudinal and transverse beam system for supporting ballastless track of high-speed railway subgrade according to claim 2, characterized in that: Concrete is poured between adjacent beams to form a composite skeleton.

4. The longitudinal and transverse beam system for supporting ballastless track of high-speed railway subgrade according to claim 1, characterized in that: An adjustable pad is provided between the crossbeam and the base plate of the ballastless track.

5. The longitudinal and transverse beam system for supporting ballastless track of high-speed railway subgrade according to claim 1, characterized in that: Stiffening ribs are provided at the joints between the crossbeam and the longitudinal beam.

6. The longitudinal and transverse beam system for supporting ballastless track of high-speed railway subgrade according to claim 1, characterized in that: Fiber optic displacement sensors are arranged at the node positions of the crossbeam and the longitudinal beam.

7. The longitudinal and transverse beam system for supporting ballastless track of high-speed railway subgrade according to claim 1, characterized in that: The crossbeam is made of double-span I-beams.

8. The longitudinal and transverse beam system for supporting ballastless track of high-speed railway subgrade according to claim 1, characterized in that: The longitudinal beams are steel box beams with internal transverse diaphragms.

9. A longitudinal and transverse beam system for supporting ballastless track of high-speed railway subgrade according to claim 1 or 8, characterized in that: The longitudinal beams adopt a segmented prefabricated assembly structure.

10. The longitudinal and transverse beam system for supporting ballastless track of high-speed railway subgrade according to claim 1, characterized in that: The temporary beam support is a precast concrete support with a sand and gravel cushion layer at its bottom.

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