High-speed railway ballastless track roadbed structure capable of preventing frost boiling and mud pumping and construction method of high-speed railway ballastless track roadbed structure

Abstract

The invention provides a high-speed railway ballastless track subgrade structure capable of preventing frost boiling and mud pumping, a waterproof step is arranged on the longitudinal edge of a base plate of the subgrade structure, and a waterproof coating is arranged on the surface of the waterproof step; filling grooves with semicircular sections are formed in the transverse side surfaces of the base plates, and the filling grooves between the adjacent base plates and expansion joints above and below the filling grooves are filled with expansion sealing glue; cement is doped into graded broken stone of the graded broken stone foundation bed according to a certain proportion; a drainage layer composed of a capillary drainage plate and a sand cushion layer is arranged on the middle layer of the graded broken stone foundation bed, the tail end of the capillary drainage plate is communicated to a drainage blind ditch, and the drainage blind ditch is communicated with a drainage hole in the outer surface of the concrete shoulder pad through a drainage channel. The invention further provides a construction method of the roadbed structure, starting from three aspects of preventing rainwater from entering the surface layer of the foundation bed, improving and curing the surface layer of the foundation bed by grading broken stones, and optimizing and perfecting a drainage system, the disease problem is solved from the source, and the mud pumping disease of the ballastless track roadbed of the high-speed railway is effectively prevented.

Description

Technical Field

[0001] The invention belongs to the technical field of railway roadbed disease prevention and treatment, and specifically relates to a high-speed railway ballastless track roadbed structure for preventing mud and slurry from bubbling, and also relates to a construction method of the high-speed railway ballastless track roadbed structure. Background Art

[0002] my country's "High-speed Railway Design Code" (TB16021-2014) requires that the surface layer of the ballastless track subgrade be filled with graded gravel, with a compaction coefficient of ≥97%, and the maximum mass proportion of particles with a particle size less than 0.1mm is no more than 5%. This makes the surface layer of the subgrade have good compaction but poor permeability.

[0003] The surface of the subgrade of the ballastless track of a high-speed railway consists of a base plate, a track plate, a track and fasteners. The area outside the base plate of the subgrade surface is sealed with concrete, and expansion joints are reserved between the base plates. Affected by the thermal expansion and contraction of concrete, cracks are easily generated between the base plate and the concrete sealing layer when the temperature is low in winter, resulting in a larger spacing between the expansion joints between the base plates. When it rains, rainwater enters the poorly permeable subgrade surface along the cracks to form water bags. Under the repeated vibration of high-speed rail vehicles, water repeatedly enters and exits the gaps between the gravel, washes and migrates fine particles, causing them to gather on the top of the subgrade surface, forming a roadbed mud disease.

[0004] Based on this, it is a technical problem that needs to be solved urgently to provide a high-speed railway ballastless track subgrade structure and a construction method thereof that can prevent slurry and mud from overflowing, so as to solve such diseases from the root. Summary of the invention

[0005] One of the purposes of the present invention is to provide a high-speed railway ballastless track subgrade structure that can prevent mud from bubbling up and down in order to overcome the deficiencies in the prior art.

[0006] A second object of the present invention is to provide a construction method for a high-speed railway ballastless track subgrade structure that prevents mud from bubbling.

[0007] The technical solution adopted by the present invention to achieve one of the purposes is: to provide a high-speed railway ballastless track subgrade structure for preventing mud from boiling, comprising: a base plate, a graded crushed stone bed below the base plate, and concrete shoulders on both sides of the graded crushed stone bed; The base plate is provided with a water-proof step along the longitudinal edge of the track, the surface of the water-proof step is provided with a waterproof coating, the surface of the water-proof step and the graded crushed stone base bed are covered with a concrete sealing layer, and the concrete sealing layer is connected to the concrete shoulder; An expansion joint is left between adjacent base plates. A filling groove with a semicircular cross section is provided on the side surface of the base plate adjacent to the expansion joint. The filling groove is arranged transversely along the track, with the middle part arched and both sides inclined downward. The filling groove and the expansion joint are filled with expansion sealing glue. The graded crushed stone of the graded crushed stone base bed is mixed with cement at 3wt.%-5wt.%; the middle layer of the graded crushed stone base bed is provided with a drainage layer, and the drainage layer includes a capillary drainage board and sand cushion layers located on the upper and lower sides thereof; the middle part of the capillary drainage board is arched and the two sides are inclined downward; A drainage blind ditch is arranged between the concrete shoulder guard and the graded crushed stone base bed, and the ends of both sides of the capillary drainage board are connected to the drainage blind ditch; a drainage hole is opened on the outer surface of the concrete shoulder guard, and the drainage hole is connected to the drainage blind ditch through a drainage channel.

[0008] The general idea of ​​the high-speed railway ballastless track subgrade structure provided by the present invention is as follows: In order to prevent the occurrence of mud and mud disease in the ballastless track of high-speed railway, the present invention starts from preventing rainwater from entering the surface layer of the subgrade, improving and solidifying the graded crushed stone on the surface layer of the subgrade, and optimizing and improving the drainage system. A high-speed railway ballastless track subgrade structure that prevents mud and mud is proposed to solve the disease problem from the source. Specifically: First, in order to avoid rainwater infiltration and control the mud-overflowing phenomenon from the source, the present invention improves the longitudinal and transverse structures of the base plate. On the one hand, a waterproof step with a waterproof coating is set at the edge of the base plate along the longitudinal direction of the track; on the other hand, the side wall of the base plate along the transverse direction of the track is improved, and a filling groove with a semicircular cross section is opened to fill the expansion sealant. Among them, the waterproof step with a waterproof coating intersects with the concrete sealing layer on the surface of the base bed, and a waterproof coating is applied to the intersection to prevent rainwater from entering the surface of the base bed along the cracks in the longitudinal direction of the track; the semicircular filling groove with a semi-cylindrical cross section reserved between the side walls of the base plate has a semi-cylindrical cavity. After the track plate is laid, the filling grooves of the adjacent base plates form a cylindrical cavity, and the expansion sealant is injected into the center of the cylindrical cavity until the expansion joints above and below the cylindrical cavity are filled. This cylindrical cavity has a large amount of glue injection, which can play a better filling and sealing role compared with conventional expansion joints, and at the same time can increase the infiltration runoff path of rainwater.

[0009] Secondly, the present invention changes the structure of graded crushed stone, adopts the method of filling the gaps in graded crushed stone with cement to solidify the graded crushed stone layer and improve the drainage system of the base bed. Specifically, 3wt.%-5wt.% of cement is added to the graded crushed stone to replace the small-sized particles in the graded crushed stone, and the pores of the large-sized particles are filled with cement to meet the compaction coefficient index requirements. At the same time, the addition of cement can also solidify the graded crushed stone layer, effectively avoiding the loss of fine particles in the graded crushed stone.

[0010] Finally, in order to further strengthen the protection, the present invention also optimizes and improves the drainage system, and also sets a transverse capillary drainage board in the middle of the subgrade surface layer, and sets a drainage blind ditch at the concrete shoulder where it is connected to the subgrade surface layer, and opens a drainage channel in the concrete shoulder. Among them, a capillary drainage board is laid transversely in the middle of the graded gravel on the subgrade surface layer, and a capillary drainage hole is set on the surface of the drainage board. The water on the subgrade surface layer is discharged through the capillary suction of the surface layer of the drainage board, and the sand cushion layer above and below the drainage board can effectively prevent the fine particles on the surface layer of the roadbed from flowing out. The setting of the drainage blind ditch and the drainage channel can ensure that the water collected by the capillary drainage board is discharged in time.

[0011] In summary, the present invention arranges a concrete water-proof step on the longitudinal edge of the base plate, a hemispherical sealing glue filling layer on the transverse side wall of the base plate, a drainage blind ditch on the roadbed shoulder, a drainage channel on the concrete shoulder, and a transverse capillary drainage board in the middle of the roadbed subgrade surface layer. The details of the present invention cooperate and work synergistically from various aspects to achieve the effect of strengthening the drainage of the subgrade surface layer and effectively prevent the occurrence of mud and slurry defects in the ballastless track subgrade of high-speed railways.

[0012] Furthermore, the height of the water-blocking step is 4-6 cm and the width is 0.8-1.2 m; the waterproof coating is coated with a waterproof coating. When the concrete shrinks, the water in the gap between the concrete sealing layer and the base plate is blocked by the waterproof coating to prevent it from entering the surface layer of the roadbed.

[0013] Preferably, the waterproof coating is selected from a combination of one or more of cement-based waterproof coating, acrylic polymer emulsion waterproof coating, and concrete anti-corrosion waterproof coating.

[0014] Furthermore, the width of the expansion joint is 0.9-1.1 cm, and the diameter of the hemispherical expansion sealant filling groove is 2.5-3.5 cm. The present invention opens a filling groove with a semicircular cross-section at the lateral edge of the base plate. After the base plate is laid, the expansion sealant is filled into the filling groove of the side wall of the base plate until the cylindrical cavity surrounded by the filling grooves of adjacent base plates and the expansion joints above and below are filled with the expansion sealant. The filling groove opened on the side wall of the base plate can increase the injection volume of the expansion sealant, and can play a better filling and sealing role compared with conventional expansion joints, reduce the gap between two adjacent base plates, and increase the infiltration runoff path of rainwater. At the same time, the cylindrical cavity surrounded by the filling grooves of the base plates on both sides can increase the contact area between the expansion sealant and the base plate. The filling volume of the expansion sealant is larger, which facilitates the compression of the base plates on both sides toward the middle. In addition, the filling groove is arranged transversely along the track, and the two sides of the middle arch are inclined downward to form a herringbone drainage slope transversely on the base plate. The herringbone drainage slope can timely discharge the water that has penetrated into the expansion sealant filling layer to avoid entering the surface layer of the base bed. Preferably, the inclination angle of the two sides of the filling groove along the horizontal direction is 3-5°.

[0015] Furthermore, the cement added to the graded crushed stone of the graded crushed stone base bed is ordinary Portland cement. The present invention uses 3wt.%-5wt.% of cement to replace the small-size particles in the graded crushed stone, and fills the pores of the large-size particles with cement to meet the compaction coefficient index requirements. When rainwater infiltrates, the cement-doped crushed stone seal can absorb moisture on the one hand, and on the other hand, it can solidify the graded crushed stone layer, effectively reducing the loss of fine particles in the graded crushed stone and preventing mud from boiling.

[0016] Furthermore, the capillary drainage board has an inclination angle of 3-5° along the horizontal direction on both sides; the upper and lower plate surfaces of the capillary drainage board are provided with a plurality of capillary drainage holes, which are connected to the water storage bag. The capillary drainage holes can absorb the water in the graded gravel into the capillary drainage board through capillary suction, and then discharge the water from the surface of the base bed through the capillary drainage board. The setting of the sand cushion layers on both sides of the capillary drainage board can filter the fine particles in the graded gravel, and avoid the loss of fine particles leading to a decrease in the compaction degree of the roadbed.

[0017] Furthermore, the sand cushion layer is made of medium-coarse sand with a particle size of 0.25-0.5 mm, and the thickness of the sand cushion layer is 4-6 cm.

[0018] Furthermore, the width of the drainage blind ditch is 0.4-0.6 m, and the drainage blind ditch is filled with gravel. The water in the base bed surface layer and the capillary drainage board is discharged into the drainage blind ditch, and the drainage blind ditch is filled with gravel to ensure smooth drainage.

[0019] Furthermore, the drainage channel of the concrete shoulder includes a first drainage channel and a second drainage channel; the first drainage channel is connected to the bottom of the sand cushion layer above the capillary drainage board; the second drainage channel is connected to the bottom of the base bed surface layer. The design of the water layer drainage channel adopted by the present invention is that the first drainage channel located in the upper layer is used to discharge the moisture on the upper part of the base bed surface layer; the second drainage channel located in the lower layer is used to discharge the moisture on the lower part of the base bed surface layer.

[0020] The technical solution adopted by the present invention to achieve the second purpose is: to provide a construction method of the high-speed railway ballastless track subgrade structure according to one of the purposes of the present invention, comprising the following steps: S1. Before filling the surface of the graded gravel base bed, lay the template and reserve the position of the drainage blind ditch on the template; S2. Add cement to the graded crushed stone and fill the surface of the subgrade in layers. Lay a sand cushion and a capillary drainage board in the middle of the subgrade until the subgrade surface is filled to the top elevation. S3. Fill the drainage blind ditch of the template with sand and gravel and compact it; S4. Build concrete shoulder guards and reserve drainage channels and drainage holes; S5. Cast the base plate and waterproof steps, and apply waterproof coating on the surface of the waterproof steps; S6. Lay a concrete sealing layer on the subgrade shoulder; S7. Fill the expansion sealing glue in the filling groove of the side wall of the base plate until the cylindrical cavity surrounded by the filling grooves of the adjacent base plates and the expansion joints above and below are filled with the expansion sealing glue.

[0021] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a high-speed railway ballastless track subgrade structure and a construction method thereof for preventing mud and mud from overflowing. Starting from preventing rainwater from entering the subgrade surface, improving and solidifying the graded crushed stone on the subgrade surface, and optimizing and improving the drainage system, a high-speed railway ballastless track subgrade structure for preventing mud and mud from overflowing is proposed to solve the problem of the disease from the source. The present invention provides a concrete water-proof step on the longitudinal edge of the base plate, a hemispherical sealing glue filling layer on the transverse side wall of the base plate, a drainage blind ditch on the subgrade shoulder, a drainage channel on the concrete shoulder, and a transverse capillary drainage board in the middle of the subgrade surface layer of the subgrade. The details cooperate and work together from multiple aspects to achieve the effect of strengthening the anti-drainage effect of the subgrade surface layer, and effectively prevent the occurrence of mud and mud on the subgrade of the high-speed railway ballastless track. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic structural diagram of a high-speed railway ballastless track subgrade structure along a track transverse cross section provided by an embodiment of the present invention; Figure 2 for Figure 1 A partial enlarged view of the middle A; Figure 3 A schematic structural diagram of a filling groove and an expansion joint between adjacent base plates in a high-speed railway ballastless track subgrade structure provided by an embodiment of the present invention along a longitudinal section of the track; Figure 4 A schematic structural diagram of a capillary drainage plate in a high-speed railway ballastless track subgrade structure provided by an embodiment of the present invention.

[0023] Among them, 1-base plate; 11-waterproof step; 12-waterproof coating; 13-concrete sealing layer; 14-expansion joint; 15-filling groove; 16-expansion sealing glue; 2-graded gravel base bed; 21-capillary drainage board; 211-capillary drainage hole; 22-sand cushion layer; 3-concrete shoulder; 31-drainage blind ditch; 32-drainage hole; 33-drainage channel; 4-track plate; 5-rail. DETAILED DESCRIPTION

[0024] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0025] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0026] like Figure 1 As shown, an embodiment of the present invention provides a high-speed railway ballastless track subgrade structure for preventing mud and slurry, comprising: a base plate 1, a graded gravel base bed 2 located below the base plate 1, and concrete shoulders 3 on both sides of the graded gravel base bed 2.

[0027] like Figure 1 and 2 As shown, the base plate 1 is provided with a water-proof step 11 along the longitudinal edge of the track, the surface of the water-proof step 11 is provided with a waterproof coating 12, the surface of the water-proof step 11 and the graded crushed stone base bed 2 is covered with a concrete sealing layer 13, and the concrete sealing layer 13 is connected to the concrete shoulder 3. Figure 3 As shown, an expansion joint 14 is left between adjacent base plates 1, and a filling groove 15 with a semicircular cross-section is opened on the side surface of the base plate 1 adjacent to the expansion joint 14. The filling groove 15 is arranged horizontally along the track, with the middle part arched and the two sides inclined downward, and the filling groove 15 and the expansion joint 14 are filled with expansion sealing glue 16.

[0028] Furthermore, the graded gravel of the graded gravel base bed 2 is mixed with cement at 3wt.%-5wt.%; the middle layer of the graded gravel base bed 2 is provided with a drainage layer, and its structure is as follows: Figure 4 As shown, the drainage layer includes a capillary drainage board 21 and sand cushion layers 22 located on the upper and lower sides thereof.

[0029] like Figure 1 As shown, the middle part of the capillary drainage board 21 is arched and the two sides are inclined downward. A drainage blind ditch 31 is provided between the concrete shoulder guard 3 and the graded crushed stone base bed 2, and the ends of the two sides of the capillary drainage board 21 are connected to the drainage blind ditch 31; the outer surface of the concrete shoulder guard 3 is provided with a drainage hole 32, and the drainage hole 32 is connected to the drainage blind ditch 31 through a drainage channel 33. The drainage channel 33 of the concrete shoulder guard 3 includes a first drainage channel and a second drainage channel; the first drainage channel is connected to the bottom of the sand cushion layer 22 above the capillary drainage board 21; the second drainage channel is connected to the bottom of the base bed surface layer.

[0030] In order to more clearly demonstrate the purpose, technical solutions and advantages of the present invention, the specific construction steps of the high-speed railway ballastless track subgrade structure for preventing mud and slurry provided by the present invention are further described in detail below in combination with the embodiments, but this is not intended to limit the present invention.

[0031] Example 1 This embodiment provides a high-speed railway ballastless track subgrade structure for preventing mud from boiling over, and its overall structure is as follows: Figure 1-4 As shown, the construction method includes the following steps: Step 1: Before filling the surface of the graded gravel base bed 2, a template is laid, and the template reserves a position for the drainage blind ditch 31; Step 2: Add ordinary Portland cement to the graded crushed stone in an amount of 4wt.% and fill the surface of the base bed in layers. Lay a sand cushion layer 22 and a capillary drainage board 21 in the middle of the base bed until the top elevation of the base bed surface is reached; wherein, the sand cushion layer 22 uses medium-coarse sand with a particle size of 0.25-0.5 mm, the thickness of the sand cushion layer 22 is 5 cm, and the inclination angle of both sides of the capillary drainage board in the horizontal direction is 4°; Step 3: Fill the template drainage blind ditch 31 with gravel and compact it. The width of the drainage blind ditch 31 is 0.5m. Step 4: construct concrete shoulder guard 3, and reserve drainage channel 33 and drainage hole 32; Step 5: Cast the base plate 1 and the waterproof step 11, the height of the waterproof step 11 is 5 cm and the width is 1 m, and a cement-based waterproof coating is applied on the surface of the waterproof step to form a waterproof coating; Step 6: Laying a concrete sealing layer 13 on the shoulder of the subgrade; Step 7: Fill the expansion sealing glue into the filling groove 15 on the side wall of the base plate 2 until the cylindrical cavity surrounded by the filling grooves 15 of the adjacent base plates 2 and the expansion joints 14 above and below are filled with the expansion sealing glue. The diameter of the filling groove 15 is 3 cm and the width of the expansion joint is 1 cm.

[0032] Example 2 This embodiment provides a high-speed railway ballastless track subgrade structure for preventing mud from boiling over, and its overall structure is as follows: Figure 1-4 As shown, the construction method includes the following steps: Step 1: Before filling the surface of the graded gravel base bed 2, a template is laid, and the template reserves a position for the drainage blind ditch 31; Step 2: Add ordinary Portland cement to the graded crushed stone in an amount of 3wt.% and fill the surface of the base bed in layers. Lay a sand cushion layer 22 and a capillary drainage board 21 in the middle of the base bed until the top elevation of the base bed surface is reached; wherein, the sand cushion layer 22 uses medium-coarse sand with a particle size of 0.25-0.5 mm, the thickness of the sand cushion layer 22 is 4 cm, and the inclination angle of both sides of the capillary drainage board in the horizontal direction is 4°; Step 3: Fill the template drainage blind ditch 31 with gravel and compact it. The width of the drainage blind ditch 31 is 0.4m. Step 4: construct concrete shoulder guard 3, and reserve drainage channel 33 and drainage hole 32; Step 5: Cast the base plate 1 and the waterproof step 11, the height of the waterproof step 11 is 4 cm, and the width is 0.8 m. Apply acrylic polymer emulsion waterproof coating on the surface of the waterproof step to form a waterproof coating; Step 6: Laying a concrete sealing layer 13 on the shoulder of the subgrade; Step 7: Fill the expansion sealing glue into the filling groove 15 on the side wall of the base plate 2 until the cylindrical cavity surrounded by the filling grooves 15 of the adjacent base plates 2 and the expansion joints 14 above and below are filled with the expansion sealing glue. The diameter of the filling groove 15 is 2.5 cm and the width of the expansion joint is 0.9 cm.

[0033] Example 3 This embodiment provides a high-speed railway ballastless track subgrade structure for preventing mud from boiling over, and its overall structure is as follows: Figure 1-4 As shown, the construction method includes the following steps: Step 1: Before filling the surface of the graded gravel base bed 2, a template is laid, and the template reserves a position for the drainage blind ditch 31; Step 2: Add ordinary Portland cement to the graded crushed stone in an amount of 5wt.% and fill the surface of the base bed in layers. Lay a sand cushion layer 22 and a capillary drainage board 21 in the middle of the base bed until the top elevation of the base bed surface is reached; wherein, the sand cushion layer 22 uses medium-coarse sand with a particle size of 0.25-0.5 mm, the thickness of the sand cushion layer 22 is 6 cm, and the inclination angle of both sides of the capillary drainage board in the horizontal direction is 4°; Step 3: Fill the template drainage blind ditch 31 with gravel and compact it. The width of the drainage blind ditch 31 is 0.6m. Step 4: construct concrete shoulder guard 3, and reserve drainage channel 33 and drainage hole 32; Step 5: Cast the base plate 1 and the waterproof step 11. The height of the waterproof step 11 is 6 cm and the width is 1.2 m. Apply concrete anti-corrosion and waterproof coating on the surface of the waterproof step to form a waterproof coating; Step 6: Laying a concrete sealing layer 13 on the shoulder of the subgrade; Step 7: Fill the expansion sealing glue into the filling groove 15 on the side wall of the base plate 2 until the cylindrical cavity surrounded by the filling grooves 15 of the adjacent base plates 2 and the expansion joints 14 above and below are filled with the expansion sealing glue. The diameter of the filling groove 15 is 3.5 cm and the width of the expansion joint is 1.1 cm.

[0034] In summary, the embodiments provided by the present invention start from three aspects: preventing rainwater from entering the surface layer of the base bed, improving and solidifying the graded gravel of the surface layer of the base bed, and optimizing and improving the drainage system, and propose a high-speed railway ballastless track subgrade structure and a construction method thereof that prevent mud from overflowing.

[0035] The present invention arranges a concrete water-proof step on the longitudinal edge of the base plate, a hemispherical sealing glue filling layer on the transverse side wall of the base plate, a drainage blind ditch on the roadbed shoulder, a drainage channel on the concrete shoulder, and a transverse capillary drainage board in the middle of the surface layer of the roadbed. The details in various aspects cooperate and work synergistically with each other to achieve the effect of strengthening the drainage of the surface layer of the base bed, solve the disease problem at the source, and effectively prevent the occurrence of mud and slurry disease of the ballastless track roadbed of the high-speed railway.

[0036] The above are only preferred embodiments of the present invention, and are not intended to limit the implementation methods and protection scope of the present invention. Those skilled in the art should be aware that all solutions obtained by equivalent substitutions and obvious changes made using the contents of the specification of the present invention should be included in the protection scope of the present invention.

Claims

1. A high-speed railway ballastless track subgrade structure for preventing mud and slurry, characterized in that: include: A base plate (1), a graded crushed stone base bed (2) located below the base plate (1), and concrete shoulders (3) on both sides of the graded crushed stone base bed (2); The base plate (1) is provided with a water-proof step (11) along the longitudinal edge of the track, the surface of the water-proof step (11) is provided with a waterproof coating (12), the surface of the water-proof step (11) and the graded crushed stone base bed (2) are covered with a concrete sealing layer (13), and the concrete sealing layer (13) is connected to the concrete shoulder (3); An expansion joint (14) is left between adjacent base plates (1), and a filling groove (15) with a semicircular cross section is provided on the side surface of the base plate (1) adjacent to the expansion joint (14). The filling groove (15) is arranged transversely along the track, with the middle part being arched and the two sides being inclined downward, and the filling groove (15) and the expansion joint (14) are filled with expansion sealing glue (16); The graded crushed stone of the graded crushed stone base bed (2) is mixed with cement at 3wt.%-5wt.%; a drainage layer is provided in the middle layer of the graded crushed stone base bed (2), and the drainage layer comprises a capillary drainage board (21) and sand cushion layers (22) located on the upper and lower sides thereof; the middle part of the capillary drainage board (21) is arched and the two sides are inclined downward; A drainage blind ditch (31) is provided between the concrete shoulder guard (3) and the graded crushed stone base bed (2), and the ends of both sides of the capillary drainage plate (21) are connected to the drainage blind ditch (31); a drainage hole (32) is provided on the outer surface of the concrete shoulder guard (3), and the drainage hole (32) is connected to the drainage blind ditch (31) through a drainage channel (33).

2. The high-speed railway ballastless track subgrade structure according to claim 1, characterized in that: The water-blocking step (11) has a height of 4-6 cm and a width of 0.8-1.2 m.

3. The high-speed railway ballastless track subgrade structure according to claim 1, characterized in that: The waterproof coating (12) is formed by coating with a waterproof coating, and the waterproof coating is selected from a combination of one or more of a cement-based waterproof coating, an acrylic polymer emulsion waterproof coating, and a concrete anti-corrosion waterproof coating.

4. The high-speed railway ballastless track subgrade structure according to claim 1, characterized in that: The width of the expansion joint (14) is 0.9-1.1 cm, and the diameter of the filling groove (15) is 2.5-3.5 cm.

5. The high-speed railway ballastless track subgrade structure according to claim 1, characterized in that: The cement added to the graded crushed stone of the graded crushed stone base bed (2) is ordinary Portland cement.

6. The high-speed railway ballastless track subgrade structure according to claim 1, characterized in that: The capillary drainage board (21) has two sides with an inclination angle of 3-5° in the horizontal direction, and a plurality of capillary drainage holes (211) are distributed on the upper and lower plate surfaces of the capillary drainage board (21).

7. The high-speed railway ballastless track subgrade structure according to claim 1, characterized in that: The sand cushion layer (22) is made of medium-coarse sand with a particle size of 0.25-0.5 mm, and the thickness of the sand cushion layer (22) is 4-6 cm.

8. The high-speed railway ballastless track subgrade structure according to claim 1, characterized in that: The width of the drainage blind ditch is 0.4-0.6 m, and the drainage blind ditch is filled with sand and gravel.

9. The high-speed railway ballastless track subgrade structure according to claim 1, characterized in that: The drainage channel (33) of the concrete shoulder guard (3) comprises a first drainage channel and a second drainage channel; the first drainage channel is connected to the bottom of the sand cushion layer (22) above the capillary drainage board (21); and the second drainage channel is connected to the bottom of the base bed surface layer.

10. The construction method of a high-speed railway ballastless track subgrade structure according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1. Before filling the surface of the graded gravel base bed (2), a template is laid, and a position for a drainage blind ditch (31) is reserved on the template; S2, adding cement to the graded crushed stone and filling the surface of the base bed in layers, laying a sand cushion layer (22) and a capillary drainage board (21) in the middle of the base bed until the top elevation of the base bed surface is reached; S3, filling the drainage blind ditch (31) of the template with sand and gravel and compacting it; S4, constructing a concrete shoulder guard (3), and reserving a drainage channel (33) and a drainage hole (32); S5, pouring the base plate (1) and the waterproof step (11), and applying a waterproof coating on the surface of the waterproof step; S6. Lay a concrete sealing layer (13) on the subgrade shoulder; S7. Fill the expansion sealing glue into the filling groove (15) of the side wall of the base plate (2) until the cylindrical cavity surrounded by the filling grooves (15) of the adjacent base plates (2) and the expansion joints (14) above and below are filled with the expansion sealing glue.

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