A roadbed structure suitable for preventing and controlling water vapor migration

Abstract

The invention discloses a roadbed structure suitable for water vapor migration prevention and control, including a roadbed body, one side of the roadbed body is a fill slope, and the other side is a cut slope, a slope drainage system and a slope support structure are arranged on the fill slope and the cut slope, the slope support structure includes a concrete covering layer, shoulder drainage ditches are arranged on both sides of the roadbed body, a drainage pipe is arranged below the shoulder drainage ditch close to the cut slope, the drainage pipe is connected with the shoulder drainage ditch above it through a seepage pipe, a water-blocking layer is arranged in the roadbed body, both sides of the water-blocking layer are inclined downward respectively, and both sides of the water-blocking layer are connected to the drainage pipe and the slope drainage system on the fill slope through drainage ports. The invention can effectively block liquid water and gaseous water in the roadbed, and is suitable for highway roadbed, railway roadbed, slope and airport high fill and other projects.

Description

Technical Field

[0001] The invention relates to a roadbed structure suitable for preventing and controlling water vapor migration. Background Art

[0002] The pot-lid effect refers to the phenomenon that the moisture content of the soil under the impermeable cover layer increases significantly. The pot-lid effect often occurs in high-fill airports in the cold and arid regions of northwest my country, and is also often found in highway subgrades, railway subgrades and civil engineering sites. The migration of gaseous water is the main cause of this phenomenon. Existing studies mainly focus on the migration of liquid water. However, under the action of freezing, the migration of gaseous water cannot be ignored and even plays a dominant role. The migration of gaseous water causes the water to continue to migrate upward from the groundwater level and accumulate on the freezing front, resulting in a significant increase in the moisture content of the frozen area, and further induces engineering diseases such as frost heave and thaw settlement, which seriously affects the operational safety of highways, railways, civil engineering sites and airports. In addition, due to the low annual average precipitation and high annual average evaporation in the cold and arid regions of northwest my country, actual projects often only simply set up liquid water prevention and control measures, such as: culverts, infiltration ditches or infiltration wells, etc. Although these measures can effectively drain the liquid water in the fill, they cannot effectively block the migration of gaseous water.

[0003] In the existing literature, a few patents have proposed methods for preventing and controlling the pot lid effect, but these patents are all proposed for roadbeds and do not consider the impact of the pot lid effect on slopes. However, for fill and excavation roadbeds in areas prone to pot lid effects, especially when steep and high multi-level slopes have to be used due to conditions, the existing technology is unable to prevent and control the significant increase in soil moisture content under the steep and high slopes. Generally speaking, for steep and high multi-level slopes, factors such as stratum lithology, geological structure, slope structure, hydrological conditions and weathering degree can have an unignorable impact on the stability of the slope. In order to ensure the stability of this type of slope, vegetation protection is generally not allowed on the slope surface, and more effective treatment measures are required, such as laying steel mesh and shotcrete. These treatment measures lead to the formation of a concrete cover layer on the slope surface, which makes it impossible for liquid water and gaseous water to exchange freely with the atmosphere through the cover layer. The pot lid effect can also occur when the groundwater level is buried deep and freezing occurs.

[0004] The existing technology has not taken this situation into consideration and only treats the roadbed, which cannot effectively prevent and control the pot-lid effect. The safe operation of projects such as highway roadbed, railway roadbed, slope and airport high fill is still threatened. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a roadbed structure suitable for preventing and controlling water vapor migration, which can effectively block liquid water and gaseous water in the roadbed and is suitable for projects such as highway roadbeds, railway roadbeds, slopes and airport high fills.

[0006] To solve the above technical problems, the technical solution adopted by the present invention is as follows:

[0007] A roadbed structure suitable for preventing and controlling water vapor migration comprises a roadbed body, one side of the roadbed body is a fill slope extending downwardly inclined, and the other side is a cut slope extending upwardly inclined, a slope drainage system and a slope support structure are provided on both the fill slope and the cut slope, the slope support structure comprises an impermeable concrete covering layer covering the slope surface of the cut slope and the fill slope, and is characterized in that: longitudinally extending shoulder drainage ditches are respectively provided on both sides of the roadbed body, a drainage pipe is provided below the shoulder drainage ditch close to the cut slope, the drainage pipe is connected to the shoulder drainage ditch above it through a plurality of vertical seepage pipes, a waterproof layer is provided at a preset depth in the roadbed body, both sides of the waterproof layer are respectively inclined downward, and both sides of the waterproof layer are connected to the drainage pipe and the slope drainage system on the fill slope through drainage outlets, and liquid water flowing along the waterproof layer to both sides thereof is discharged to the drainage pipe and the slope drainage system on the fill slope respectively.

[0008] Furthermore, a plurality of slope exposure holes penetrating the concrete covering layer are provided on the concrete covering layer of the excavated slope, and a shielding structure is provided at each slope exposure hole to prevent external liquid water from entering the interior through the slope exposure hole.

[0009] Furthermore, the shielding structure includes an outwardly protruding arc-shaped baffle plate arranged on the upper half of the slope exposure hole and a transparent shield plate shielding the front of the slope exposure hole, and a gap is left between the transparent shield plate and the side of the slope exposure hole for discharging gaseous water outward.

[0010] Furthermore, pins are provided on the transparent shielding plate, and the pins are inserted into the soil at the exposed hole of the slope, so as to fix the transparent shielding plate.

[0011] Furthermore, the transparent shield is a transparent polyethylene plate.

[0012] Furthermore, the waterproof layer includes two cloths and one membrane and a middle sand layer laid on the upper and lower sides of the two cloths and one membrane.

[0013] Furthermore, the two sides of the waterproof layer are inclined downward at a slope of 4%.

[0014] Furthermore, a plurality of transverse drainage pipes are provided in the shoulder of the road base body close to the fill slope, and the transverse drainage pipes are connected with the drainage ditch of the shoulder close to the fill slope and the slope drainage system on the fill slope.

[0015] Furthermore, a permeable geogrid is provided at the drainage outlet to prevent the internal soil from being lost.

[0016] Furthermore, the slope drainage system on the fill slope includes a plurality of fill slope drainage ditches extending downwardly on the fill slope surface, and the slope drainage system on the cut slope includes a plurality of cut slope drainage ditches extending downwardly on the cut slope surface and a longitudinally extending intercepting ditch arranged on the top of the cut slope.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1. The present invention provides an impermeable layer at a preset depth in the roadbed, and the two sides of the impermeable layer are respectively inclined downward. When gaseous water moves to the impermeable layer, it will condense into liquid water on the impermeable layer and be discharged to the slope drainage system and drainage pipe of the fill slope on both sides, which can effectively prevent and control the pot cover effect generated in the roadbed, thereby preventing and controlling engineering diseases such as freezing and thawing caused by the pot cover effect.

[0019] 2. The present invention also provides slope exposure holes on the concrete cover layer of the excavated slope. Through the slope exposure holes, the soil in the excavated slope can absorb sunlight, so that the moisture in the soil can be effectively evaporated, thereby effectively preventing and controlling the pot cover effect generated at the excavated slope position and engineering diseases such as freeze-thaw caused by the pot cover effect.

[0020] 3. The implementation process of the present invention is clear and simple, the construction process is easy to operate, and the required materials are easy to obtain, the price is economical, and no additional burden is added.

[0021] 4. The present invention has wide applicability, and is not only applicable to high-fill projects in cold and arid areas, but also to projects such as highway subgrades, railway subgrades, and civil engineering sites, and the service life of these projects is greatly improved by preventing and controlling the pot cover effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the structure of the present invention;

[0023] Figure 2 It is a schematic diagram of the main structure of the slope surface of the excavation slope of the present invention;

[0024] Figure 3 It is a side view structural schematic diagram of the anchor rod and the slope exposure hole at the excavation slope of the present invention;

[0025] Figure 4 It is a schematic diagram of the main structure of the slope exposure hole of the present invention;

[0026] Figure 5 It is a schematic structural diagram of the water-proof layer of the present invention;

[0027] Figure 6 It is a schematic diagram of the main structure of the slope surface of the fill slope of the present invention;

[0028] Figure 7It is a schematic diagram of the top view of the structure of the shoulder drainage ditch close to the excavation slope of the present invention.

[0029] Meaning of reference numerals in the figure:

[0030] 1. Road basic structure; 2. Fill slope; 3. Cut slope; 3-1. First-level cut slope; 4. Drainage outlet; 5. Drainage pipe; 6. Pad layer; 7. Seepage pipe; 8. Shoulder drainage ditch; 9. Horizontal drainage pipe; 10. Water-proof layer; 10-1. Middle sand layer; 10-2. Two cloths and one membrane; 11. Cut slope drainage pipe; 12. Anchor rod; 12-1. Anchor head; 12-2. Free section; 12-3. Anchor section; 13. Slope exposed hole; 13-1. Arc baffle; 13-2. Transparent shield; 13-3. Pin; 14. Cut slope drainage ditch; 15. Permeable geogrid; 16. Water grate; 17. Fill slope drainage ditch. DETAILED DESCRIPTION

[0031] The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict. For the convenience of description, if the words "upper", "lower", "left" and "right" appear in the following, they only indicate that the upper, lower, left and right directions are consistent with the drawings themselves, and do not limit the structure.

[0032] like Figures 1 to 7 The roadbed structure suitable for water vapor migration prevention and control in this embodiment is shown, which includes a roadbed body 1, the right side of the roadbed body 1 is a fill slope 2 extending downwardly, and the left side is a cut slope 3 extending upwardly. The cut slope 3 in this embodiment includes multiple levels, among which the lowest level close to the roadbed body 1 is the first-level cut slope 3-1. Slope drainage systems and slope support structures are provided on the fill slope 2 and the cut slope 3. The slope support structure includes an impermeable concrete covering layer covering the slope surface of the cut slope and the fill slope and an anchor rod 12 for increasing the stability of the slope. The anchor head 12-1 of the anchor rod 12 is made of concrete and has a square shape. It is fixed on the surface of the concrete covering layer, and the square is rotated 45° to facilitate the water flow downward along the slope surface. The anchoring section 12-3 of the anchor rod 12 is located in the soil, and the anchoring section 12-3 is connected to the anchor head 12-1 through a free section 12-2.

[0033] The slope drainage system on the fill slope 2 of this embodiment includes a plurality of fill slope drainage ditches 17 extending downwardly on the surface of the fill slope, and the slope drainage system on the excavation slope 3 includes a plurality of excavation slope drainage ditches 14 extending downwardly on the surface of the excavation slope 3 and a longitudinally extending intercepting ditch arranged on the top of the excavation slope 3 (the intercepting ditch is a conventional structure and is not shown in the figure).

[0034] On both sides of the road base body 1, longitudinally extending shoulder drainage ditches 8 are provided, and a drainage pipe 5 is provided below the shoulder drainage ditch 8 near the excavation slope 3, and a cushion layer 6 is laid at the bottom of the drainage pipe 5. The drainage pipe 5 is connected to the shoulder drainage ditch 8 above it through multiple vertical seepage pipes 7, and multiple seepage pipes 7 are arranged in the longitudinal direction, and a water grate 16 is provided at the upper end of the seepage pipe 7. A waterproof layer 10 is provided at a preset depth in the road base body 1, and the preset depth is greater than the freezing depth of the geographical location of the road base body 1. The two sides of the waterproof layer 10 are inclined downward respectively, and the two sides of the waterproof layer 10 are connected to the drainage pipe 5 and the fill slope drainage ditch 17 of the slope drainage system on the fill slope 2 through the drainage port 4. Specifically, the inner end of the drain outlet 4 extends to the corresponding side of the waterproof layer 10, so that the liquid water flowing to the side of the waterproof layer 10 can flow into the drain outlet 4 through the inner end of the drain outlet 4, wherein the outer end of the drain outlet 4 on the side where the drainage pipe 5 is located is connected to the top or the middle of the drainage pipe 5. Since the water level of the liquid water in the drainage pipe 5 is generally not very high during use, there is no need to worry about the liquid water in the drainage pipe 5 backflowing into the soil of the circuit basic body 1, wherein the outer end of the drain outlet 4 on the side where the fill slope 2 is located is connected to the fill slope drainage ditch 17 on the fill slope 2. During use, the gaseous water that moves to the waterproof layer 10 will condense into liquid water on the waterproof layer 10, and the liquid water that flows along the waterproof layer 10 to both sides thereof will be discharged to the drainage pipe 5 and the fill slope drainage ditch 17 of the slope drainage system of the fill slope through the drainage outlet 4, thereby effectively preventing and controlling the pot lid effect generated in the road base body 1. Of course, the liquid water that moves to the waterproof layer 10 will also be discharged to the slope drainage system and drainage pipe of the fill slope through the drainage outlet along the waterproof layer to both sides thereof.

[0035] In order to effectively prevent and control the pot cover effect generated at the excavation slope 3, a plurality of slope exposure holes 13 penetrating the concrete cover layer are provided on the concrete cover layer of the excavation slope 3, and a shielding structure is provided at each slope exposure hole 13 to prevent external liquid water from entering the interior through the slope exposure hole. Figure 2 As shown, the slope holes 13 at different heights are arranged on the same straight line, which is beneficial to the drainage of the slope surface. When there is an anchor head 12-1 with an anchor rod, the slope holes 13 at the corresponding positions and the anchor head 12-1 at the corresponding positions are arranged on the same straight line.

[0036] The shielding structure includes an outwardly protruding arc baffle 13-1 provided on the upper half of the slope exposure hole 13 and a transparent shield 13-2 shielding the slope exposure hole 13. The arc baffle 13-1 is made of concrete and can prevent the water flowing downward along the slope from entering the soil of the excavated slope along the slope exposure hole 13. The transparent shield 13-2 can prevent atmospheric precipitation from flowing into the soil of the excavated slope 3 along the slope exposure hole 13, and can also enable the soil at the excavated slope 3 to absorb sunlight better and evaporate the water in the soil. A gap is left between the transparent shield 13-2 and the side of the slope exposure hole 3, and the gaseous water formed by evaporation is discharged outward through the gap.

[0037] The transparent shielding plate 13-2 of this embodiment is a transparent polyethylene plate, and four pins 13-3 are provided on one side thereof. The pins 13-3 pass through the slope exposure hole 13 and are inserted into the soil at the slope exposure hole, thereby fixing the transparent shielding plate 13-2.

[0038] like Figure 5 As shown, the waterproof layer 10 of this embodiment includes two cloths and one membrane 10-2 and a middle sand layer 10-1 laid on the upper and lower sides of the two cloths and one membrane. The middle sand layer 10-1 can also protect the two cloths and one membrane 10-2 to prevent them from being damaged by sharp-edged stone chips, stones or other objects during the rolling process.

[0039] A plurality of transverse drainage pipes 9 are provided in the shoulder of the road base body 1 near the fill slope 2, and the transverse drainage pipes 9 connect the shoulder drainage ditch 8 near the fill slope 2 and the fill slope drainage ditch 17 of the slope drainage system on the fill slope 2, so that the water flow in the shoulder drainage ditch 8 near the fill slope 2 can be discharged outward to the slope drainage system through the transverse drainage pipes 9.

[0040] Dense permeable geogrids 15 are provided at the drainage outlets 4 to prevent the loss of internal soil. The permeable geogrids 15 can effectively discharge the moisture inside the middle sand layer 10-1 and effectively prevent the middle sand in the middle sand layer 10-1 from flowing out with the water flow, thereby avoiding the internal soil at this position from being hollowed out.

[0041] In this embodiment, a cut slope drainage pipe 11 is shallowly buried on the cut slope, and the cut slope drainage pipe 11 is connected to the drainage pipe 5 .

[0042] A specific construction structure and process of the above-mentioned roadbed structure are as follows:

[0043] Before the construction of the project, soil samples are taken at the planned and selected location for indoor or on-site tests to determine the basic physical, mechanical and hydraulic parameters of the soil at that location, and then design calculations and analysis are carried out to determine the reasonable slope support and excavation plan for that location. Then, excavation operations are carried out on multi-level excavation slopes, the surface cultivated soil of the excavation slopes is removed and placed outside the scope of the project location, and the soil with better properties at the bottom of the slope is placed at the location where filling is required.

[0044] When excavating a multi-level excavation slope 3, graded excavation should be carried out. In order to eliminate the impact of soil unloading during excavation, excavation should start from the top of the slope and be carried out according to the designed slope support and excavation plan, using the principle of excavation and support. The top excavation slope can be supported by vegetation or other means, and only the slope surface needs to be maintained from being damaged, and a drainage ditch should be set at the top of the slope. Other levels of excavation slopes should also be operated according to the design plan, and steps can be appropriately set between the levels of excavation slopes.

[0045] In the design and excavation plan of the multi-cut slope 3, the first-level cut slope 3-1 should adopt a stronger slope support structure to ensure the overall stability of the slope. These slope support structures will lead to the formation of an impermeable concrete cover layer on the slope surface, blocking the free exchange of water between the soil and the atmosphere. At the same time, the slope support structure should also be equipped with anchor rods 12 to enhance the stability of the slope. The spacing, material and distribution of the anchor rods 12, as well as the length of the anchoring section 12-3 should be determined through design calculations. The anchor head 12-1 of the anchor rod is concrete, square in shape, and rotated 45° to facilitate the flow of water down the slope surface. The support of other levels of cut slopes is determined by the design plan.

[0046] A cut slope drainage ditch 14 is set on the slope surface of the first-level cut slope 3-1. The cut slope drainage ditch 14 is built with concrete. The spacing between the cut slope drainage ditches 14 is determined according to the climate and precipitation conditions, and is connected with the cut slope drainage ditches 14 on other levels of slopes. The bottom of the cut slope drainage ditch 14 is connected to the shoulder drainage ditch 8 at the foot of the slope. The shoulder drainage ditch 8 should be provided with a water grate 16. The spacing between the water grate 16 should not be too large. A seepage pipe 7 is set at the bottom of the water grate 16 and connected to the drainage pipe 5 at the bottom, which can effectively guide the water flow on the road base body and the slope into the drainage pipe 5 at the bottom. A 50cm thick cushion layer 6 is laid at the bottom of the drainage pipe 5 at the bottom of the slope foot.

[0047] A slope hole 13 is set on the slope surface of the first-level excavation slope 3-1. The diameter of the slope hole 13 should not be too large, preferably 20 cm. A 5 cm high concrete arc baffle 13-1 is set along the upper half of the slope hole 13 to prevent the slope water from penetrating into the soil below the concrete cover along the slope hole. A transparent polyethylene plate is set on the upper part of the slope hole 13, and the pins 13-3 on the polyethylene plate are inserted and fixed in the soil inside the slope hole to prevent atmospheric precipitation from flowing in along the slope hole. It can also better absorb sunlight to effectively evaporate the moisture in the soil inside the slope hole. The arrangement of the slope holes is consistent with the anchor head, and is in the same straight line on the slope surface, which is conducive to slope drainage. At other positions without anchor heads, the slope holes are set in parallel with a spacing of 3m.

[0048] Remove the cultivated soil or miscellaneous fill soil on the surface of the road base body 1, remove the soil with poor properties at this location, and replace the soil with better properties within the thickness of the road base body 1 according to relevant specifications. Roll the replacement soil in layers and meet the compaction requirements required by the specifications. Related studies on the pot lid effect show that when the temperature is lower than the freezing temperature of the soil, the moisture content in the soil below the impermeable cover layer on the upper part of the road base body will increase significantly, and the gaseous water flux in the frozen zone cannot be ignored, and is of the same order of magnitude as the liquid water flux; the moisture content at the freezing front will also increase significantly, but the increase is less than that of the soil layer below the impermeable cover layer. The research results also show that under freezing conditions, the migration of water vapor from the groundwater table is the main cause of the pot lid effect.

[0049] According to the statistical data of freezing depth in the region for many years, the approximate freezing depth of the location is obtained. When the road base body 1 is rolled to below the freezing depth of the location, two cloths and one membrane 10-2 are laid, and the position of the two cloths and one membrane 10-2 should not be less than 50cm from the freezing depth. On both sides of the two cloths and one membrane 10-2, a 10cm thick medium sand layer 10-1 is laid. The slope of the two sides of the two cloths and one membrane 10-2 and the medium sand layer 10-1 on both sides is 4%, which is conducive to the discharge of water. The two cloths and one membrane 10-2 can effectively block the continued upward migration of water, and when the gaseous water migrates upward from the groundwater level to the two cloths and one membrane 10-2, it condenses into liquid water at this position, and is discharged to both sides of the road base body through the geotextile and the lower medium sand layer, and discharged to the drainage pipe 5 at the bottom of the foot of the first-level excavation slope to the left, and discharged to the drainage ditch of the fill slope to the right. The middle sand layer 10-1 on the upper and lower sides can also protect the two cloths and one membrane, thereby preventing the two cloths and one membrane from being damaged by sharp-edged stone chips, stones or other objects during the rolling process.

[0050] After the base bed of the road base body 1 is paved, the concrete pavement is poured, and a longitudinal shoulder drainage ditch 8 is set at the shoulder of the road base body 1. In the longitudinal direction of the shoulder drainage ditch 8, a transverse drainage pipe 9 is set every 10m. A fill slope drainage ditch 17 made of mortared rubble is set on the slope surface of the fill slope 2. The top of the fill slope drainage ditch 17 is connected to the transverse drainage pipe 9 of the shoulder, and the end of the fill slope drainage ditch 17 is connected to a nearby river or other drainage channel. The water on the surface of the road base body 1 can be timely collected into the shoulder drainage ditch 8, and through the transverse drainage pipe 9, it flows down along the fill slope drainage ditch 17 to a nearby river or other drainage channel.

[0051] The right side of the two cloths and one membrane 10-2 in the road base body 1 and the middle sand layer 10-1 on both sides of the two cloths and one membrane are connected to the fill slope drainage ditch 17 on the fill slope through the drainage port 4. The drainage port 4 has a diameter of 10 cm and is sealed with a denser permeable geogrid 15. The permeable geogrid 15 can effectively discharge the moisture inside the middle sand layer 10-1, and can also effectively prevent the middle sand from flowing out with the water flow, thereby avoiding the hollowing out of the internal soil at this position.

[0052] The two cloths and one membrane 10-2 and the middle sand layers 10-1 on both sides thereof, the excavation slope drainage ditch 14 and the intercepting ditch on the top of the multi-level excavation slope surface, the shoulder drainage ditch 8 and the drainage pipe 5 at the bottom of the foot of the first-level excavation slope 3-1, the shoulder drainage ditch 8 on the right side of the roadbed body 1, and the fill slope drainage ditch 17 on the fill slope 2 surface together constitute a pot cover effect prevention and control structure for the roadbed when there is a steep and high slope. It can not only effectively prevent liquid water from flowing into the roadbed, but also effectively block the migration of gaseous water upward to the freezing depth range. In addition, it can also effectively discharge the liquid water under the concrete cover layer of the steep and high slope, and the gaseous water that migrates and accumulates there.

[0053] The contents explained in the above embodiments should be understood as these embodiments are only used to more clearly illustrate the present invention, and are not used to limit the scope of the present invention. After reading the present invention, various equivalent forms of modifications to the present invention by those skilled in the art all fall within the scope defined by the claims attached to this application.

Claims

1. A roadbed structure suitable for preventing and controlling water vapor migration, comprising a roadbed body, one side of the roadbed body is a fill slope extending downwardly, and the other side is a cut slope extending upwardly, a slope drainage system and a slope support structure are provided on the fill slope and the cut slope, and the slope support structure comprises an impermeable concrete covering layer covering the slope surface of the cut slope and the fill slope, characterized in that: A longitudinally extending shoulder drainage ditch is provided on both sides of the road base body, a drainage pipe is provided below the shoulder drainage ditch near the cut slope, the drainage pipe is connected to the shoulder drainage ditch above it through a plurality of vertical seepage pipes, a waterproof layer is provided at a preset depth within the road base body, both sides of the waterproof layer are inclined downward, both sides of the waterproof layer are connected to the drainage pipe and the slope drainage system on the fill slope through drainage ports, and liquid water flowing along the waterproof layer to both sides thereof is discharged to the drainage pipe and the slope drainage system on the fill slope respectively; A plurality of slope exposure holes penetrating the concrete covering layer are provided on the concrete covering layer of the excavated slope, and a shielding structure is provided at each of the slope exposure holes to prevent external liquid water from entering the interior through the slope exposure hole; The shielding structure includes an outwardly protruding arc-shaped baffle plate provided on the upper half of the side slope exposure hole and a transparent shield plate shielding the front of the side slope exposure hole, and a gap is left between the transparent shield plate and the side of the side slope exposure hole for discharging gaseous water outward; The waterproof layer comprises two cloths and one membrane and a middle sand layer laid on the upper and lower sides of the two cloths and one membrane.

2. The roadbed structure suitable for preventing and controlling water vapor migration according to claim 1, characterized in that: Pins are arranged on the transparent shielding plate, and the pins are inserted into the soil at the exposed hole of the slope, so as to fix the transparent shielding plate.

3. The roadbed structure suitable for preventing and controlling water vapor migration according to claim 1 or 2, characterized in that: The transparent shielding plate is a transparent polyethylene plate.

4. The roadbed structure suitable for preventing and controlling water vapor migration according to claim 1, characterized in that: The two sides of the waterproof layer are inclined downward at a slope of 4%.

5. The roadbed structure suitable for preventing and controlling water vapor migration according to claim 1, characterized in that: A plurality of transverse drainage pipes are arranged in the shoulder of the road base body close to the fill slope, and the transverse drainage pipes are connected with the shoulder drainage ditch close to the fill slope and the slope drainage system on the fill slope.

6. The roadbed structure suitable for preventing and controlling water vapor migration according to claim 1, characterized in that: A permeable geogrid is provided at the drain outlet to prevent the internal soil from being lost.

7. The roadbed structure suitable for preventing and controlling water vapor migration according to claim 1, characterized in that: The slope drainage system on the fill slope includes a plurality of fill slope drainage ditches extending downwardly on the slope surface of the fill slope, and the slope drainage system on the cut slope includes a plurality of cut slope drainage ditches extending downwardly on the slope surface of the cut slope and a longitudinally extending intercepting ditch arranged on the top of the cut slope.

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