Double-block type ballastless track roadbed slab anti-cracking structure

Abstract

The utility model discloses a double-block type ballastless track roadbed slab anti-cracking structure which comprises a roadbed slab, a base and a prefabricated sleeper, the top of the roadbed slab is connected with the prefabricated sleeper, a limiting groove is formed in the base, the bottom of the roadbed slab is placed in the limiting groove of the base, a steel rail is arranged at the top of the prefabricated sleeper and connected with the prefabricated sleeper through a connecting piece, and the prefabricated sleeper is connected with the base. Ring-shaped anti-crack steel bars are arranged on the top plane of the roadbed slab, the prefabricated sleeper ring is sleeved in the center, and the roadbed slab structure is further filled with anti-crack concrete; through the organic combination of the ring-shaped anti-crack steel bars and the overskirt type anti-crack gridding cloth, an anti-crack barrier is established around the prefabricated sleeper, when shrinkage stress concentration is generated by roadbed slab cast-in-place concrete due to hydration and water loss drying, stress can be dispersed through the combination of the ring-shaped anti-crack steel bars and the overskirt type anti-crack gridding cloth; the phenomenon that the roadbed slab structure concrete is prone to cracking in a splayed shape at the four corners of the prefabricated sleeper is avoided, and the crack resistance and durability of the ballastless track roadbed slab structure are achieved.

Description

Technical Field

[0001] This utility model belongs to the field of building construction technology. More specifically, this utility model relates to a crack-resistant structure for a double-block ballastless track bed slab. Background Technology

[0002] Ballastless track, with its advantages of good stability, simple construction methods, and low maintenance, has been widely used in my country's high-speed railway construction. Among these, the twin-block ballastless track is one of the main types and also the structural type with the longest laying mileage and most mature design and construction at present. Because the track slab of the twin-block ballastless track is a cast-in-place reinforced concrete structure, its construction quality is easily affected by environmental factors, concrete properties, and management level. Engineering surveys have revealed that cracking in ballastless track is very common in my country's high-speed railway construction and operation, especially in the track slab structure. The cast-in-place track slab concrete often forms V-shaped cracks extending outwards at 45° near the four corners of the precast sleepers. In severe cases, these cracks even penetrate the thickness of the track slab, potentially causing water seepage into the interior, leading to problems such as steel corrosion, insulation failure, and frost heave in the subgrade. This not only affects the safety and service durability of the track structure but also brings many challenges to construction, acceptance, and subsequent operation, maintenance, and repair.

[0003] Currently, the solution to the problem of "figure-eight" cracks easily occurring at the four corners of the sleepers in double-block ballastless track slabs is to perform multiple finishing and smoothing processes after the concrete is poured and before it sets, but the effect is not ideal.

[0004] Chinese patent document CN220284493U discloses a crack-resistant structural system for CRTSⅠ type double-block ballastless track slabs. The technical solution mainly reduces cracking at the four corners of prefabricated sleepers by laying crack-resistant mesh at these corners. This structural system has a complex operation process, the placement and positioning of the crack-resistant mesh is difficult, there are many details to control during construction, and it requires high operational skills from construction personnel, making it unsuitable for large-scale application.

[0005] Chinese patent document CN209602874U discloses a tensile-resistant and crack-resistant railway sleeper. Its technical solution mainly involves cutting off the four corners of the sleeper body and replacing them with a low-modulus composite material of the same volume and shape. The low modulus of elasticity of the composite material reduces stress concentration in the track bed concrete at the four corners of the sleeper, thereby reducing the probability of "figure-eight" cracks appearing at the sleeper corners. However, this structural process requires cutting the four corners of all prefabricated sleepers and replacing them with composite materials, resulting in high labor intensity and economic costs, which is not conducive to large-scale application.

[0006] In summary, how to reduce the risk of cracking at the four corners of the sleepers in a cost-effective and easy-to-operate manner is an urgent problem to be solved in the construction of ballastless track slabs. Utility Model Content

[0007] This utility model addresses the shortcomings of existing technologies by providing a double-block anti-crack structure for ballastless track slabs. It solves the cracking problems in existing ballastless track slabs, such as concrete cracking, V-shaped cracks at the four corners of sleepers, and transverse through cracks on the slab surface. It achieves the goals of simple operation, economic efficiency, and good crack control.

[0008] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0009] A crack-resistant structure for a double-block ballastless track slab includes a track slab, a base, and precast sleepers. The top of the track slab is connected to the precast sleepers. The base has a limiting groove, and the bottom of the track slab is placed in the limiting groove of the base. The top of the precast sleepers is provided with rails, and the rails are connected to the precast sleepers through connectors. The top plane of the track slab is arranged with ring-shaped crack-resistant steel bars, which encircle the precast sleepers in the center. The track slab structure is also filled with crack-resistant concrete.

[0010] This utility model discloses a crack-resistant structure for a double-block ballastless track slab. The track slab is also provided with a skirt-type crack-resistant mesh cloth. The material of the skirt-type crack-resistant mesh cloth is polyoxymethylene fiber. One end of the skirt-type crack-resistant mesh cloth is sewn around the ring-shaped crack-resistant steel bar and connected to the ring-shaped crack-resistant steel bar. The other end is spread out in a flat state around the precast sleeper.

[0011] This utility model discloses a crack-resistant structure for a double-block ballastless track bed slab, wherein the connecting component is composed of a W1 type elastic strip and a rubber pad.

[0012] This utility model discloses a crack-resistant structure for a double-block ballastless track slab, wherein the prefabricated sleeper is a CRTSⅠ type double-block sleeper for high-speed railways.

[0013] This utility model discloses a crack-resistant structure for a double-block ballastless track bed slab, wherein the surface of the ring-shaped crack-resistant steel bars is coated with an epoxy coating.

[0014] This utility model discloses a double-block ballastless track bed slab anti-crack structure, wherein the overlapping length of the ring-shaped anti-crack steel bars is 150mm and the diameter of the ring-shaped anti-crack steel bars is 8mm. The ring-shaped anti-crack steel bars and the skirt-type anti-crack mesh cloth assembly are placed on the upper longitudinal steel bars of the track bed slab.

[0015] Compared with the prior art, the present invention has the following advantages:

[0016] This invention establishes a simple crack-resistant barrier around precast sleepers by organically combining ring-shaped crack-resistant steel bars with skirt-type crack-resistant mesh fabric. When the cast-in-place concrete of the track bed slab experiences stress concentration at the four corners of the precast sleepers due to its own shrinkage, the combined structure of the ring-shaped crack-resistant steel bars and skirt-type crack-resistant mesh fabric can disperse and consume the shrinkage stress, reducing the stress at the corners of the cast-in-place concrete and thus preventing the "figure-eight" cracking phenomenon that easily occurs at the four corners of the precast sleepers. This achieves crack resistance and durability of the ballastless track bed slab structure.

[0017] The present invention will be described in more detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0018] The following is a brief explanation of the contents of each of the accompanying drawings and the markings in the drawings:

[0019] Figure 1 This is a schematic diagram of the present invention;

[0020] Figure 2 A schematic diagram of the planar arrangement of the ring-shaped crack-resistant steel bar and the skirt-type crack-resistant mesh fabric of this utility model around the prefabricated sleeper.

[0021] The markings in the diagram are: 1. Track slab; 2. Base; 3. Precast sleeper; 4. Rail; 5. Connector; 6. Ring-shaped anti-crack steel bar; 7. Skirt-type anti-crack mesh fabric. Detailed Implementation

[0022] The following description, with reference to the accompanying drawings, further details the specific implementation methods of this utility model, including the shape and structure of each component, the relative positions and connections between the parts, the function and working principle of each part, the manufacturing process, and the operation and use methods, so as to help those skilled in the art to have a more complete, accurate, and in-depth understanding of the utility model concept and technical solution.

[0023] like Figure 1 and Figure 2 The diagram shows a double-block ballastless track slab anti-crack structure, including a track slab 1, a base 2, and precast sleepers 3. The top of the track slab 1 is connected to the precast sleepers 3. The base 2 is provided with a limiting groove, and the bottom of the track slab 1 is placed in the limiting groove of the base 2. The top of the precast sleepers 3 is provided with rails 4, and the rails 4 are connected to the precast sleepers 3 through connectors 5. The top plane of the track slab 1 is provided with ring-shaped anti-crack steel bars 6, which encircle the precast sleepers 3 in the center. The structure of the track slab 1 is also filled with anti-crack concrete.

[0024] The track bed slab 1 is also equipped with a skirt-type anti-crack mesh cloth 7. The material of the skirt-type anti-crack mesh cloth 7 is polyoxymethylene fiber. One end of the skirt-type anti-crack mesh cloth 7 is sewn around the ring-shaped anti-crack steel bar 3 and connected to the ring-shaped anti-crack steel bar 3. The other end is spread out in a flat state around the precast sleeper.

[0025] Connector 5 consists of a W1 type spring strip and a rubber pad.

[0026] Precast sleeper 3 is a CRTSⅠ type double-block sleeper for high-speed railways.

[0027] The surface of the ring-shaped crack-resistant steel bar 6 is coated with an epoxy coating.

[0028] The stacked length of the ring-shaped crack-resistant steel bar 6 is 150mm, the diameter of the ring-shaped crack-resistant steel bar 6 is 8mm, and the ring-shaped crack-resistant steel bar 6 and the skirt-type crack-resistant mesh cloth 7 are placed on the upper longitudinal steel bar of the track bed slab 1.

[0029] Working principle and method

[0030] The working principle of this utility model is to place a set of ring-shaped anti-crack steel bars 6 and skirt-type anti-crack mesh cloth 7 around the precast sleepers 3 on the track slab 1 to form an anti-crack structure. When the cast-in-place track slab 1 concrete begins to shrink and deform, the shrinkage stress increases and concentrates around the precast sleepers 3. When it encounters the skirt-type anti-crack mesh cloth 7, the shrinkage stress is decomposed, consumed, and weakened by the various anti-crack mesh units in the skirt-type anti-crack mesh cloth 7. When the residual shrinkage stress develops to the vicinity of the ring-shaped anti-crack steel bars 6, it is further blocked and weakened. In this way, the anti-crack structure of the ring-shaped anti-crack steel bars 6 and the skirt-type anti-crack mesh cloth 7 forms two anti-crack lines around the precast sleepers 3 to reduce the development of stress concentration, thereby reducing the probability of "figure-eight" cracks appearing at the four corners of the precast sleepers 3 and improving the crack resistance and durability of the overall structure of the ballastless track slab.

[0031] The present invention has been described above with reference to the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any non-substantial improvements made using the inventive concept and technical solution of the present invention, or the direct application of the inventive concept and technical solution to other situations without modification, are all within the protection scope of the present invention.

Claims

1. A crack-resistant structure for a double-block ballastless track slab, comprising a track slab, a base, and precast sleepers, wherein the top of the track slab is connected to the precast sleepers, the base is provided with a limiting groove, and the bottom of the track slab is placed within the limiting groove of the base, characterized in that, The precast sleeper is equipped with a rail on top and the rail is connected to the precast sleeper through a connector. The top plane of the track bed slab is arranged with ring-shaped anti-crack steel bars that encircle the precast sleeper in the center. The track bed slab structure is also filled with anti-crack concrete.

2. The anti-crack structure for a double-block ballastless track bed slab according to claim 1, characterized in that, The track bed slab is also equipped with a skirt-type anti-crack mesh cloth. The material of the skirt-type anti-crack mesh cloth is polyoxymethylene fiber. One end of the skirt-type anti-crack mesh cloth is sewn around the ring-shaped anti-crack steel bar and connected to the ring-shaped anti-crack steel bar. The other end is spread out in a flat state around the precast sleeper.

3. The anti-crack structure for a double-block ballastless track slab according to claim 1, characterized in that, The connector consists of a W1 type spring strip and a rubber pad.

4. The anti-crack structure for a double-block ballastless track slab according to claim 1, characterized in that, The prefabricated sleepers are CRTSⅠ type double-block sleepers for high-speed railways.

5. The anti-crack structure for a double-block ballastless track slab according to claim 1, characterized in that, The surface of the ring-shaped crack-resistant steel bar is coated with an epoxy coating.

6. The anti-crack structure for a double-block ballastless track slab according to claim 1, characterized in that, The overlapping length of the ring-shaped crack-resistant steel bars is 150mm, and the diameter of the ring-shaped crack-resistant steel bars is 8mm. The ring-shaped crack-resistant steel bars and the skirt-type crack-resistant mesh fabric assembly are placed on the upper longitudinal steel bars of the track bed slab.

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