High-speed railway subgrade pavement structure in seasonally frozen ground region

Abstract

The application discloses a high-speed railway subgrade ballastless track pavement structure in a seasonal frozen soil area, and relates to the technical field of high-speed railway subgrade ballastless tracks in a seasonal frozen soil area. The high-speed railway subgrade ballastless track pavement structure comprises a pavement structure main body, a filler layer and a concrete cover layer covering the outer side of the filler layer. A ventilation opening is arranged on the top of the pavement structure main body, penetrates through the concrete cover layer and communicates with the filler layer, so that the water vapor generated in the subgrade in summer can be discharged, and the ventilation opening is provided with a waterproof and ventilating structure. The high-speed railway subgrade ballastless track pavement structure can discharge the high-temperature water vapor generated in the subgrade in summer, prevent the water vapor from gathering and condensing into water on the upper part of the subgrade, inhibit the "pot cover effect" of the high-speed railway subgrade ballastless track, and achieve the purpose of reducing the frost heaving in winter.

Description

Technical Field

[0001] This invention relates to the field of ballastless track technology for high-speed railway subgrades in seasonally frozen soil areas, and in particular to a roadbed and pavement structure for ballastless track of high-speed railways in seasonally frozen soil areas. Background Technology

[0002] The existing roadbed structure, based on considerations of waterproofing and overall stability, adopts a ballastless track pavement structure, such as... Figures 1-2 As shown, the surface layer is entirely cast in concrete and is in a sealed state. In summer, when temperatures are high, moisture evaporates from the lower subgrade and migrates upwards. Due to the lack of vents, water vapor accumulates on the surface, increasing the surface moisture content—a phenomenon commonly known as the "boiler effect." In seasonally frozen soil regions, frost heave in high-speed railway subgrades mainly occurs in the upper and middle layers (above 1.5m), with frost heave reaching up to 30% of the total in the crushed stone layer (above 0.5m). This phenomenon indicates a high moisture content in the surface layer. Since high-speed railways use a ballastless track structure with good integrity and sealing, external rainwater infiltration is relatively likely. Therefore, the surface water mainly originates from the evaporation and migration of moisture from the lower subgrade in summer, cooling and accumulating on the surface, leading to high frost heave in winter. Therefore, a new pavement structure is urgently needed to solve the aforementioned problems in existing technologies. Summary of the Invention

[0003] The purpose of this invention is to provide a roadbed and pavement structure for high-speed railway ballastless track in seasonally frozen soil areas, in order to solve the problems existing in the prior art. It can discharge the high-temperature water vapor generated in the roadbed in summer, prevent water vapor from condensing into water on the upper part of the roadbed, thereby suppressing the "boiler effect" of high-speed railway ballastless track and achieving the purpose of reducing roadbed frost heave in winter.

[0004] To achieve the above objectives, the present invention provides the following solution:

[0005] This invention provides a roadbed and pavement structure for high-speed railway ballastless track in seasonally frozen soil areas, including a pavement structure body. The pavement structure body includes a filler layer and a concrete cover layer covering the outside of the filler layer. Ventilation openings are symmetrically provided on both sides of the top of the pavement structure body. The ventilation openings penetrate the concrete cover layer and communicate with the filler layer to allow water vapor generated in the roadbed in summer to be discharged. The ventilation openings are provided with waterproof and breathable structures.

[0006] Preferably, the filler layer includes a first filler layer and a second filler layer laid sequentially from bottom to top, wherein the first filler layer is a coarse particle filler layer and the second filler layer is a crushed stone filler layer.

[0007] Preferably, the coarse particle packing layer is formed by laying coarse particle packing, which is a packing formed by mixing group A packing and group B packing.

[0008] Preferably, the crushed stone filler layer is made of graded crushed stone with a particle size of 8cm-10cm.

[0009] Preferably, a composite waterproof geotextile layer is laid at the bottom of the first filler layer and between the first filler layer and the second filler layer.

[0010] Preferably, a composite waterproof geotextile layer is laid on top of the second filler layer, and an opening is provided on the composite waterproof geotextile layer on top of the second filler layer, the opening corresponding to the vent.

[0011] Preferably, the ventilation openings are provided on both sides of the top of the main road structure, and the ventilation openings are arranged along the entire length of the track line.

[0012] Preferably, the waterproof and breathable structure is a waterproof barrier wall, which is an inverted L-shaped structure including a side barrier wall and a top barrier wall. The side barrier wall is vertically arranged on the side of the vent near the track, and the top barrier wall is horizontally arranged. One side of the top barrier wall is connected to the top of the side barrier wall, and the other side of the top barrier wall extends toward the vent away from the track and covers the vent.

[0013] Preferably, the waterproof and breathable structure is a waterproof and breathable material layer, which covers the vent, and the top of the waterproof and breathable material layer is flush with the top of the main road structure.

[0014] Preferably, the waterproof and breathable material layer is made of silicone-modified Ms road construction material.

[0015] The present invention achieves the following technical effects compared to the prior art:

[0016] The main body of the pavement structure of this invention has a vent at the top, which is connected to the filler layer. There are two layers of composite waterproof geotextile between the vent and the subgrade. The composite geotextile has the function of preventing liquid water and allowing water vapor to pass through, so that the high-temperature water vapor (water vapor) generated in the subgrade in summer can be discharged, and water vapor is prevented from being trapped in the upper structure of the subgrade and condensing into water. This suppresses the "boiler effect" of the ballastless track of the high-speed railway and achieves the purpose of reducing frost heave in winter. Moreover, the waterproof and breathable structure at the vent can prevent rainwater infiltration and allow water vapor to be discharged. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the subgrade structure of a high-speed railway in cold regions using existing technology.

[0019] Figure 2 A schematic diagram of the "bowl lid effect" in existing high-speed railway subgrade structures in cold regions;

[0020] Figures 1-2 In the middle: 1-subgrade, 2-subgrade slope structure, 3-frost depth line;

[0021] Figure 3 This is a schematic diagram of the ballastless track subgrade and pavement structure of a high-speed railway in a seasonally frozen soil region according to Embodiment 1 of the present invention.

[0022] Figure 4 This is a partially enlarged schematic diagram of the ballastless track subgrade and pavement structure of a high-speed railway in a seasonally frozen soil region according to Embodiment 1 of the present invention.

[0023] Figure 5 This is a schematic diagram of the waterproof and breathable structure in Embodiment 1 of the present invention;

[0024] Figure 6 This is a schematic diagram of the ballastless track subgrade and pavement structure of a high-speed railway in a seasonally frozen soil region according to Embodiment 2 of the present invention.

[0025] Figure 7 This is a schematic diagram of the waterproof and breathable material layer in Embodiment 2 of the present invention.

[0026] Figures 3-7 In the middle: 100-subgrade, 200-subgrade and pavement structure of high-speed railway ballastless track in seasonally frozen soil areas, 201-first filler layer, 202-second filler layer, 203-concrete cover layer, 204-ventilation opening, 205-composite waterproof geotextile layer, 300-waterproof retaining wall, 301-side retaining wall, 302-top retaining wall, 400-waterproof and breathable material layer. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] The purpose of this invention is to provide a roadbed and pavement structure for high-speed railway ballastless track in seasonally frozen soil areas, in order to solve the problems existing in the prior art. It can discharge the high-temperature water vapor generated in the roadbed in summer, prevent water vapor from condensing into water on the upper part of the roadbed, thereby suppressing the "boiler lid effect" of high-speed railway ballastless track and achieving the purpose of reducing frost heave in winter.

[0029] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0030] Example 1

[0031] like Figures 3-5 As shown, this embodiment provides a ballastless track subgrade pavement structure 200 for high-speed railways in seasonally frozen soil areas. The pavement structure main body includes a filler layer and a concrete cover layer 203 covering the outside of the filler layer. A vent 204 is provided on the top of the pavement structure main body. The vent 204 penetrates the concrete cover layer 203 and communicates with the filler layer to allow water vapor generated in the subgrade 100 in summer to be discharged. The vent 204 is provided with a waterproof and breathable structure.

[0032] In this embodiment, a vent 204 is provided on the top of the main pavement structure. The vent 204 is connected to the filler layer so that the high-temperature water vapor (water vapor) generated in the roadbed 100 in summer can be discharged, and the water vapor is prevented from condensing into water in the upper structure of the roadbed. This suppresses the "boiler effect" of the ballastless track of the high-speed railway and achieves the purpose of reducing frost heave in winter. Moreover, the waterproof and breathable structure at the vent can prevent rainwater from seeping in and allow water vapor to be discharged.

[0033] In this embodiment, the filler layer includes a first filler layer 201 and a second filler layer 202 laid sequentially from bottom to top, wherein the first filler layer 201 is a coarse particle filler layer and the second filler layer 202 is a crushed stone filler layer.

[0034] Specifically, the coarse particle filler layer is laid with coarse particle filler, which is a mixture of group A filler and group B filler. Group A filler is mainly composed of pebbles and boulders with a particle size greater than 5 cm, while group B filler is composed of gravel, coarse sand and a small amount of silt, wherein the content of fine particles with a particle size less than 0.02 mm does not exceed 1%. In this embodiment, group A filler and group B filler are used together to form coarse particle filler, which can ensure that the pavement structure has a certain degree of compaction to meet the strength and deformation requirements, and can also ensure that the filler has a certain porosity to improve the frost heave resistance.

[0035] In this embodiment, the crushed stone filler layer is made of graded crushed stone with a particle size of 8cm-10cm.

[0036] In this embodiment, a composite waterproof geotextile layer 205 is laid at the bottom of the first filler layer 201 and between the first filler layer 201 and the second filler layer 202. Furthermore, a composite waterproof geotextile layer 205 can also be laid on top of the second filler layer 202, and an opening is provided on the composite waterproof geotextile layer 205 at the top of the second filler layer 202, the opening corresponding to the vent 204.

[0037] In this embodiment, as Figure 3 As shown, the ventilation openings 204 are provided on both sides of the top of the main body of the road structure, and the ventilation openings 204 are arranged along the entire length of the track line; in this embodiment, ventilation openings 204 are provided on both sides of the top of the main body of the road structure to form a "U-shaped structure" to accelerate summer convection and allow water vapor in the roadbed 100 to be discharged quickly.

[0038] In this embodiment, as Figure 4 and Figure 5 As shown, the waterproof and breathable structure is a waterproof retaining wall 300, which is an inverted L-shaped structure, including a side retaining wall 301 and a top retaining wall 302. The side retaining wall 301 is vertically arranged on the side of the vent 204 near the track, and the top retaining wall 302 is horizontally arranged, with one side of the top retaining wall 302 connected to the top of the side retaining wall 301. The other side of the top retaining wall 302 extends towards the vent 204 away from the track and covers the vent 204. Further, the second filler layer 202 covers the vent 204, meaning the vent 204 is filled with graded crushed stone from the second filler layer 202. In this embodiment, the waterproof retaining wall 300 prevents rainwater infiltration and allows moisture to escape through the gap between the waterproof retaining wall 300 and the main road structure. It is also convenient to construct, easy to maintain, and low in cost.

[0039] In this embodiment, the waterproof retaining wall 300 is preferably a concrete retaining wall with the same thickness as the concrete cover layer 203, preferably 3cm. The overall height of the waterproof retaining wall 300 is 10cm. The top retaining wall 302 of the waterproof retaining wall 300 covers both sides of the vent 204 and extends to both sides by a certain distance. Specifically, the width of the vent 204 is preferably 1m, and the top retaining wall 302 extends 20cm to each side based on the vent 204, that is, the overall width of the top retaining wall 302 is 1.4m.

[0040] In this embodiment, the slope of both sides of the main road structure is preferably 1.5.

[0041] Example 2

[0042] This embodiment is an improvement on Embodiment 1, and the main difference from Embodiment 1 is:

[0043] like Figure 6 and Figure 7 As shown, in this embodiment, the waterproof and breathable structure is preferably a waterproof and breathable material layer 400. The waterproof and breathable material layer 400 covers the vent 204, which can allow water vapor generated inside the roadbed to be discharged when the summer temperature is high, while inhibiting the infiltration of free water on the ground surface; moreover, the top of the waterproof and breathable material layer 400 is flush with the top of the main road structure, making the road surface on both sides of the track smooth.

[0044] In this embodiment, the waterproof and breathable material layer 400 is preferably made of silicone-modified Ms road construction material; wherein, the silicone-modified Ms road construction material is made by adding silicone to anhydrous tung oil and allyl polyether diol, which has low material cost, waterproof and stain-resistant properties, good breathability, strong practicality, and can be widely used.

[0045] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A pavement structure for ballastless track subgrade of high-speed railway in seasonally frozen soil areas, comprising a pavement structure main body, wherein the pavement structure main body includes a filler layer and a concrete capping layer covering the outside of the filler layer, characterized in that: The top of the main road structure is provided with a vent, which penetrates the concrete cover layer and communicates with the filler layer. The vent is also provided with a waterproof and breathable structure. The filler layer includes a first filler layer and a second filler layer laid from bottom to top. The first filler layer is a coarse particle filler layer, and the second filler layer is a crushed stone filler layer. The coarse particle filler layer is made of coarse particle filler, which is a mix of group A filler and group B filler. A composite waterproof geotextile layer is laid at the bottom of the first filler layer and between the first filler layer and the second filler layer; a composite waterproof geotextile layer is laid on the top of the second filler layer, and an opening is provided on the composite waterproof geotextile layer at the top of the second filler layer, the opening corresponding to the vent. The main body of the road surface structure has ventilation openings on both sides of its top, and the ventilation openings are arranged along the entire length of the track. The waterproof and breathable structure is a waterproof retaining wall, which is an inverted L-shaped structure, including a side retaining wall and a top retaining wall. The side retaining wall is vertically set on the side of the ventilation opening near the track, and the top retaining wall is horizontally set. One side of the top retaining wall is connected to the top of the side retaining wall, and the other side of the top retaining wall extends toward the side of the ventilation opening away from the track and covers the ventilation opening.

2. The ballastless track subgrade and pavement structure for high-speed railways in seasonally frozen soil areas according to claim 1, characterized in that: The crushed stone filler layer is made of graded crushed stone with a particle size of 8cm-10cm.

3. The ballastless track subgrade and pavement structure for high-speed railways in seasonally frozen soil areas according to claim 1 or 2, characterized in that: The waterproof and breathable structure is a waterproof and breathable material layer, which covers the vent, and the top of the waterproof and breathable material layer is flush with the top of the main road structure.

4. The ballastless track subgrade and pavement structure for high-speed railways in seasonally frozen soil areas according to claim 3, characterized in that: The waterproof and breathable material layer is made of silicone-modified Ms road construction material.

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