Ballastless track roadbed full-section composite sealing layer and active waterproof and drainage structure and method

Abstract

The invention discloses a ballastless track roadbed full-section composite sealing layer and an active waterproof and drainage structure and method, and belongs to the technical field of railway roadbeds. An active waterproof and drainage structure for a full-section composite sealing layer of a ballastless track roadbed comprises the full-section sealing layer and cable troughs arranged on two sides of the roadbed, and is characterized in that a multi-surface-layer composite material is laid at the bottom of the full-section sealing layer; the two transverse ends of the multi-surface-layer composite material sequentially extend out of the roadbed from the top face of the roadbed bed along the side wall, located on the inner side of the roadbed bed, of the cable trough and the bottom of the cable trough to wrap the roadbed, the two transverse ends of the multi-surface-layer composite material extend out of the roadbed by a certain length, and the end, extending out of the roadbed, of the multi-surface-layer composite material and the top face of the roadbed bed form a height difference. The multi-surface-layer composite material comprises a rough hair hook layer, a water absorption material layer and a waterproof layer which are sequentially arranged into a whole from top to bottom, and the multi-surface-layer composite material is combined with the concrete of the full-section sealing layer into a whole through the rough hair hook layer. Water can be effectively prevented from permeating into the subgrade bed.

Description

Technical Field

[0001] The present invention relates to a full-section composite sealing layer for a ballastless track subgrade, and also to an active waterproof and drainage structure and an active waterproof and drainage method for the full-section composite sealing layer of the ballastless track subgrade, belonging to the technical field of railway subgrades. Background Art

[0002] At present, the scale of the high-speed railway network is constantly expanding. As the foundation for laying railway tracks, the smoothness and long-term stability of the subgrade are crucial for the safe operation of high-speed trains. Various diseases of the subgrade, such as mud pumping, settlement extrusion, frost damage, etc., are all related to the change of the water content in the subgrade. Therefore, in order to ensure the firmness and stability of the subgrade, the primary task is to do a good job in the waterproof and drainage of the subgrade.

[0003] At present, the waterproof sealing layer of high-speed railway subgrades mainly uses cement-based concrete materials. Due to the large brittleness and poor deformation adaptability of concrete materials, the concrete of the sealing layer is prone to cracking due to external environmental changes and transportation vibrations, etc., resulting in water easily seeping into the subgrade bed, causing the water content in the subgrade bed to be too high and resulting in diseases such as mud pumping. In addition, there are a large number of longitudinal and transverse structural joints in the existing waterproof sealing layer, and there are situations such as separation of the structural joints in the caulking materials during the service period, which are also prone to cause water to seep into the subgrade bed. For example: there is a vertical structural joint between the cast-in-place full-section sealing layer and the precast cable trench cover plate. Therefore, water flow can easily seep into the subgrade bed from here, resulting in various subgrade bed diseases. The loss of stability of the subgrade bed will have an adverse impact on the normal use of the railway, and it is more difficult to maintain and repair the situation of too high water content in the subgrade bed and cracking of the sealing layer in the later stage.

[0004] Preventing water from softening the subgrade bed is the fundamental for treating diseases such as mud pumping in the subgrade. Laying composite materials with both water-blocking and drainage functions can effectively reduce the effects of slurry formation and upwelling of dynamic loads. However, traditional geosynthetic products can only provide gravity-induced lateral drainage and require the soil near the geosynthetic materials to reach a saturated state, and their waterproof and drainage effects are not good. Summary of the Invention

[0005] In view of the above-mentioned defects existing in the prior art, the present invention provides an active waterproof and drainage structure for a full-section composite sealing layer of a ballastless track subgrade that can actively waterproof and drain.

[0006] The present invention is realized through the following technical solutions: A full-section composite closed layer active water drainage and prevention structure for a ballastless track subgrade, including a full-section closed layer provided on the surface of the subgrade bed, and cable troughs provided on both sides of the subgrade. It is characterized in that: a multi-layer composite material is laid at the bottom of the full-section closed layer, and the transverse two ends of the multi-layer composite material extend from the top surface of the subgrade bed along the inner side walls of the cable troughs located on the subgrade bed and the bottom of the cable troughs to wrap the subgrade outward, and both transverse ends of the multi-layer composite material extend out of the subgrade by a certain length. There is a height difference between the part where the multi-layer composite material extends out of the subgrade and the top surface of the subgrade bed. The multi-layer composite material includes a rough hook layer, a water absorption material layer, and a waterproof layer which are integrally arranged from top to bottom. The multi-layer composite material is combined with the concrete of the full-section closed layer through its rough hook layer.

[0007] In the present invention, the function of the rough hook layer in the multi-layer composite material is as follows: on the one hand, by setting the rough hook layer, when the closed layer concrete is cast in place, it is closely attached to the bottom of the closed layer, ensuring that the multi-layer composite material is combined with the concrete as a whole and ensuring the strength of the closed layer. On the other hand, the rough hook layer can effectively prevent the closed layer concrete from cracking; the water absorption material layer in the multi-layer composite material has high water absorption performance and is used to absorb the water infiltrated from the cracks or structural joints of the closed layer; the waterproof layer in the multi-layer composite material is a water-impermeable layer and is used to prevent water from infiltrating into the subgrade bed. Since the multi-layer composite material wraps the subgrade from the bottom of the cable trough, a height difference is formed. The water absorbed by the multi-layer composite material is easy to migrate outward from the subgrade. The part of the multi-layer composite material extending out of the subgrade is exposed to the air, and the water contained in it can be evaporated and consumed into the air through evaporation or directly discharged to the outside of the subgrade. At this time, the moisture content at both ends of the multi-layer composite material is lower than that in the middle. For a porous medium, its moisture content is inversely proportional to the suction force. Therefore, when the moisture content of the water absorption material at the ends of the multi-layer composite material becomes smaller, its suction force increases, thereby adsorbing the moisture in the middle to migrate to both ends. After the moisture in the middle water absorption material decreases, it continues to adsorb the moisture in the soil base, and the moisture is actively discharged through continuous circulation. At the same time, due to the continuous evaporation of the moisture at both ends of the multi-layer composite material and the migration of the middle moisture to both ends, a negative pressure is formed between the cracked and uncracked parts of the closed layer concrete, and the moisture can be quickly discharged actively.

[0008] Further, the part of the multi-layer composite material extending out of the subgrade extends to the side ditch. By extending the part extending out of the subgrade to the side ditch, the water can be discharged to the side ditch.

[0009] Further, in order to improve the water absorption performance of the water absorption material, the water absorption material layer of the multi-layer composite material uses profiled fibers. By using profiled fibers, the water absorption performance of the water absorption material can be improved.

[0010] Further, to improve the effect of active drainage, the multi-layer composite material extends horizontally from the bottom of the cable trench to the outside of the subgrade; or the multi-layer composite material extends obliquely downward from the outer end of the bottom of the cable trench to the outside of the subgrade.

[0011] The present invention also provides an active drainage method for the active drainage structure of the ballastless track subgrade full-section composite closed layer described above, which is characterized in that: the water infiltrated from the cracks of the full-section closed layer and the gap between the cable trench and the subgrade is absorbed by the water-absorbing material layer of the multi-layer composite material, and the waterproof layer of the multi-layer composite material prevents the water from infiltrating into the subgrade bed. The water absorbed by the water-absorbing material layer gradually migrates outward from the subgrade through the height difference formed between the end of the multi-layer composite material extending out of the subgrade and the top surface of the subgrade, and the water absorbed by the multi-layer composite material continuously evaporates into the air or discharges the adsorbed water to the outside of the subgrade through the end of the multi-layer composite material extending out of the subgrade, so that the water absorbed by the multi-layer composite material migrates from the middle to both ends and is discharged, and the active discharge of water is realized through continuous circulation.

[0012] The present invention also provides a ballastless track subgrade full-section composite closed layer, and the technical solution adopted is: a ballastless track subgrade full-section composite closed layer, including a full-section closed layer, which is characterized in that: a multi-layer composite material is laid at the bottom of the full-section closed layer, and the multi-layer composite material includes a coarse hair hook layer, a water-absorbing material layer, and a waterproof layer which are sequentially arranged as a whole from top to bottom, and the multi-layer composite material is integrated with the concrete of the full-section closed layer through its coarse hair hook layer.

[0013] The beneficial effects of the present invention are as follows: By laying a multi-layer composite material at the bottom of the full-section sealing layer, the coarse hair hook layer of the multi-layer composite material enables the concrete of the sealing layer to closely adhere to the bottom of the sealing layer during the cast-in-place process, improving the strength of the sealing layer. Moreover, the combination of the coarse hair hook layer and the concrete of the sealing layer can effectively prevent the concrete of the sealing layer from cracking. The water-absorbing material layer in the multi-layer composite material can efficiently absorb the water infiltrated from the cracks or structural joints of the sealing layer, and the waterproof layer in the multi-layer composite material can effectively prevent the water from infiltrating into the subgrade bed. By wrapping the subgrade from the bottom of the cable trough with the multi-layer composite material, a height difference is formed, and by extending both ends of the multi-layer composite material out of the subgrade by a certain length, the water contained in the multi-layer composite material exposed to the air at the end extending out of the subgrade evaporates into the air, thereby causing the water in the middle to migrate to both ends, and continuously circulating to achieve the active discharge of water. By arranging the multi-layer composite material, the present invention can quickly absorb water, effectively prevent water from penetrating to the bottom of the subgrade, improve the drainage efficiency, and can also control the water content of the nearby subgrade filling through the multi-layer composite material, thereby preventing diseases such as mud pumping in the ballast bed caused by the increase in the water content of the subgrade bed. At the same time, the addition of the multi-layer composite material is similar to the soil composite reinforcement material, which not only ensures the stability of the structure but also improves the overall strength and stiffness of the subgrade. Compared with the traditional waterproof method, the present invention can effectively improve the waterproof performance of the structure, reduce the intrusion of water into the subgrade bed, ensure the stability of the subgrade bed, reduce the occurrence frequency of subgrade bed diseases, ensure the safe and normal operation of the railway, and the construction of the present invention is relatively simple, reducing the construction difficulty. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is the layout diagram of the active waterproof and drainage structure of the present invention in the specific implementation manner;

[0015] Figure 2 is the schematic diagram of the action mechanism of the active waterproof and drainage structure of the present invention in the specific implementation manner (the green in the figure is the water flow);

[0016] Figure 3 is the water flow through diagram of the traditional structure (the green in the figure is the water flow);

[0017] Figure 4 is the water flow through diagram of the present invention (the green in the figure is the water flow);

[0018] Figure 5 is the cross-sectional schematic diagram of the multi-layer composite material in the present invention;

[0019] In the figure, 1, subgrade bed; 2, full-section sealing layer; 3, multi-layer composite material; 4, cover plate; 5, cable trough; 6, drain pipe; 7, side ditch.

[0020] 3.1, coarse hair hook layer; 3.2, water-absorbing material layer; 3.3, waterproof layer. Detailed implementation manners

[0021] The present invention will be further described below by way of non-limiting embodiments in conjunction with the accompanying drawings:

[0022] As shown in the attached Figure 1 figure, an active drainage structure with a full-section composite closed layer for a ballastless track subgrade includes a full-section closed layer 2 provided on the surface of the subgrade bed 1, cable trenches 6 provided on both sides of the subgrade. A multi-layer composite material 3 is laid at the bottom of the full-section closed layer 2. In the cross-sectional direction of the subgrade, the transverse ends of the multi-layer composite material 3 extend from the top surface of the subgrade bed 1 along the side walls of the cable trench 5 located inside the subgrade bed and the bottom of the cable trench 5 to the outside of the subgrade in sequence, wrapping the subgrade to form a complete protective layer. Moreover, both transverse ends of the multi-layer composite material 3 extend out of the subgrade by a certain length, and there is a height difference between the end of the multi-layer composite material 3 extending out of the subgrade and the top surface of the subgrade bed 1. The part of the multi-layer composite material 3 extending out of the subgrade should ensure a certain length so that the adsorbed moisture can be consumed by air evaporation or discharged to the outside of the subgrade. Preferably, the end of the multi-layer composite material 3 extending out of the subgrade extends into the side ditch 7 provided on the side of the subgrade. By extending the end of the multi-layer composite material 3 extending out of the subgrade into the side ditch 7, the moisture can be discharged into the side ditch 7.

[0023] To improve the active drainage effect, preferably, the multi-layer composite material 3 extends horizontally from the bottom of the cable trench 5 to the outside of the subgrade; or the multi-layer composite material 3 extends obliquely downward from the outer end of the bottom of the cable trench 5 to the outside of the subgrade.

[0024] As shown in the attached Figure 5As shown in the figure, the multi-layer composite material 3 in the present invention includes a coarse hair hook layer 3.1, a water-absorbing material layer 3.2, and a waterproof layer 3.3 that are integrally arranged from top to bottom. The multi-layer composite material 3 is integrally combined with the concrete of the full-section closing layer 2 through its coarse hair hook layer 3.1. The coarse hair hook layer 3.1 in the multi-layer composite material 3 is a rough surface, which can be a geotextile with a roughened surface, that is, the surface of the traditional geotextile is roughened. The function of the coarse hair hook layer 3.1 is to maintain roughness, so as to ensure close fitting with the bottom of the closing layer during the in-situ casting of the concrete of the full-section closing layer 2, ensure the integration of the multi-layer composite material 3 and the concrete of the full-section closing layer 3, ensure the strength of the closing layer, and effectively prevent the concrete of the full-section closing layer 2 from cracking through the coarse hair hook layer 3.1, reducing the cracks in the closing layer. The water-absorbing material layer 3.2 in the multi-layer composite material 3 is mainly used to absorb the water infiltrated from the cracks or structural joints of the closing layer. The water-absorbing material layer 3.2 has high water absorption performance, and it can adopt materials with high strength and high water absorption in the existing technology to ensure that the water infiltrated when the closing layer cracks can be quickly absorbed and discharged. For example, the water-absorbing material layer 3.2 can adopt special-shaped sponges in the existing technology, or geotextiles recorded in the Chinese patent document with the literature number CN 206752228 U, or other materials with high water absorption performance. To improve the water absorption performance of the water-absorbing material, it is preferred that the water-absorbing material layer 3.2 of the multi-layer composite material 3 adopts special-shaped fibers. Special-shaped fibers refer to chemical fibers with special cross-sectional shapes spun through spinneret holes with certain geometric shapes. The cross-section of the special-shaped fibers can be cross-shaped, tree-shaped, orange-petal-shaped, etc. The waterproof layer 3.3 in the multi-layer composite material is a waterproof layer that prevents water from infiltrating into the subgrade bed. The waterproof layer 3.3 can adopt the existing technology. For example, the waterproof layer 3.3 can form a waterproof layer by coating waterproof glue on the geotextile, or adopt other waterproof materials in the existing technology that can maintain stability and excellent waterproof performance under different environmental conditions. The coarse hair hook layer 3.1, the water-absorbing material layer 3.2, and the waterproof layer 3.3 can be combined into one body by bonding.

[0025] As shown in the attached Figure 2 figure, the active water drainage method of the active water drainage structure of the full-section composite closing layer of the ballastless track subgrade: the water infiltrated from the full-section closing layer cracks and the gaps between the cable trough and the subgrade is absorbed by the water-absorbing material layer 3.2 of the multi-layer composite material 3, and the waterproof layer 3.3 of the multi-layer composite material 3 prevents water from infiltrating into the subgrade bed 1. The water absorbed by the water-absorbing material layer 3.2 gradually migrates out of the subgrade through the height difference formed between the end of the multi-layer composite material 3 extending out of the subgrade and the subgrade top surface, and the water absorbed by the multi-layer composite material 3 continuously evaporates into the air or discharges the adsorbed water out of the subgrade through the end of the multi-layer composite material 3 extending out of the subgrade, so that the water absorbed by the multi-layer composite material 3 migrates from the middle to both ends and is discharged, and the active discharge of water is continuously realized through continuous circulation.

[0026] Since the multi-layer composite material 3 wraps the roadbed from the bottom of the cable trench 5, a height difference is formed. The water absorbed by the multi-layer composite material 3 is easily migrated outward from the roadbed. The part of the multi-layer composite material 3 extending outside the roadbed is exposed to the air, and the water contained in it can be evaporated and consumed into the air through evaporation or directly discharged outside the roadbed. At this time, the moisture content at both ends of the multi-layer composite material 3 is lower than that in the middle. For a porous medium, its moisture content is inversely proportional to the suction. Therefore, the decrease in the moisture content of the water-absorbing material at the end of the multi-layer composite material 3 will increase its suction, thereby adsorbing the moisture in the middle and migrating it to both ends. After the moisture in the middle water-absorbing material decreases, it continues to adsorb the moisture in the subgrade, and the active discharge of moisture is realized through continuous circulation. At the same time, due to the continuous evaporation of the moisture at both ends of the multi-layer composite material and the migration of the middle moisture to both ends, and the bottom of the multi-layer composite material is an impermeable layer, the cracked and uncracked parts of the closed layer concrete form a negative pressure, which can quickly realize the active discharge of moisture.

[0027] As shown in the Figure 3 figure is the water flow diagram of the traditional structure. In the traditional structure, surface water such as rainwater will penetrate into the roadbed subgrade 1 through the cracks of the full-section closed layer 2 and the gap between the cable trench cover plate 4 and the full-section closed layer 2, and cannot be discharged, resulting in too high water content in the roadbed subgrade and causing diseases such as mud pumping, affecting the normal use of the railway.

[0028] As shown in the Figure 4 figure is the water flow diagram of the present invention. In the present invention, after surface water such as rainwater penetrates through the cracks of the full-section closed layer 2 and the gap between the cable trench cover plate 4 and the full-section closed layer 2, it is continuously absorbed by the multi-layer composite material 3 attached to the bottom of the full-section closed layer 2, and the waterproof layer at the bottom of the multi-layer composite material 3 prevents water from penetrating into the roadbed subgrade. The water absorbed by the multi-layer composite material 3 migrates and is discharged outward from the roadbed through the bottom of the cable trench 5, thereby effectively preventing surface water such as rainwater from entering the subgrade through the cracks of the closed layer and the gap between the cable trench on both sides of the subgrade and the closed layer.

[0029] The present invention utilizes the multi-layer structure of the composite material, which can not only realize the waterproof and drainage functions of the structure, effectively prevent water from penetrating into the subgrade, but also improve the strength of the closed layer, reduce the cracking of the closed layer, thereby preventing diseases such as mud pumping in the ballast bed caused by the increase in the water content of the subgrade.

[0030] During the specific construction of the present invention, first, the preparation work of the roadbed is carried out to ensure that the roadbed is flat and meets the design requirements. Then, a multi-layer composite material with appropriate specifications is designed and laid and fixed on the surface of the roadbed. When fixing, it is necessary to ensure that it fits tightly against the surface of the roadbed. The composite material can be tightly connected to the roadbed structure through fixing devices or connectors to prevent it from moving or deforming during use. Then, the cable trench is constructed to ensure that it fits tightly against the graded crushed stone of the roadbed. Finally, the full-section closed layer is cast in situ. The corresponding dimensions and technical requirements of each part should be determined by on-site technical personnel according to the actual situation such as the climate zone of the proposed project location. When selecting the composite material, a composite material with high water absorption and high strength should be selected to ensure its stability and waterproof performance under different environmental conditions. The mechanical properties, hydraulic properties, durability properties, and friction coefficient between it and the soil of the composite material and other indicators should preferably be determined through tests. When the test conditions are not available, they should be determined in combination with engineering experience or relevant data to ensure that it plays its due role.

[0031] Other parts in this embodiment are all prior arts and will not be elaborated here.

Claims

1. An active waterproof and drainage structure for the full-section composite closed layer of a ballastless track subgrade, comprising a full-section closed layer arranged on the surface of the subgrade bed and cable channels arranged on both sides of the subgrade, characterized in that: A multi-layer composite material is laid at the bottom of the full-section closed layer. The transverse two ends of the multi-layer composite material extend and wrap the subgrade from the top surface of the subgrade bed along the side walls of the cable trough located inside the subgrade bed and the bottom of the cable trough in sequence, and both transverse ends of the multi-layer composite material extend out of the subgrade by a certain length. There is a height difference between the end of the multi-layer composite material extending out of the subgrade and the top surface of the subgrade bed. The multi-layer composite material includes a coarse hair hook layer, a water-absorbing material layer, and a waterproof layer which are sequentially arranged as a whole from top to bottom. The multi-layer composite material is integrated with the concrete of the full-section closed layer through its coarse hair hook layer.

2. The active water drainage and prevention structure of the full-section composite closed layer of the ballastless track subgrade according to claim 1, characterized in that: The end of the multi-layer composite material extending out of the subgrade extends to the side ditch.

3. The active water drainage and prevention structure of the full-section composite closed layer of the ballastless track subgrade according to claim 1, characterized in that: The water-absorbing material layer of the multi-layer composite material uses special-shaped fibers.

4. The active drainage prevention structure of the full-section composite closed layer for ballastless track subgrade according to any one of claims 1-3, characterized in that: The multi-layer composite material extends horizontally out of the subgrade from the bottom of the cable trough; or the multi-layer composite material extends obliquely downward from the outer end of the bottom of the cable trough to the outside of the subgrade.

5. An active waterproof and drainage method for the active waterproof and drainage structure of the full-section composite closed layer of the ballastless track subgrade according to any one of claims 1-4, characterized in that: The water seeping in through the cracks of the full-section closed layer and the gaps between the cable trough and the subgrade is absorbed by the water-absorbing material layer of the multi-layer composite material. The waterproof layer of the multi-layer composite material prevents the moisture from seeping into the subgrade bed. The moisture absorbed by the water-absorbing material layer gradually migrates out of the subgrade through the height difference formed between the end of the multi-layer composite material extending out of the subgrade and the subgrade top surface, and the moisture absorbed by the multi-layer composite material continuously evaporates into the air or discharges the adsorbed water out of the subgrade through the end of the multi-layer composite material extending out of the subgrade, so that the moisture absorbed by the multi-layer composite material migrates from the middle to both ends and is discharged continuously, and the active discharge of moisture is realized through continuous circulation.

6. A ballastless track subgrade full-section composite sealing layer, including a full-section sealing layer, characterized in that: at A multi-layer composite material is laid at the bottom of the full-section closed layer. The multi-layer composite material includes a coarse hair hook layer, a water-absorbing material layer, and a waterproof layer which are sequentially arranged as a whole from top to bottom. The multi-layer composite material is integrated with the concrete of the full-section closed layer through its coarse hair hook layer.

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