Expansive soil composite roadbed structure and construction method

Abstract

The invention relates to an expansive soil composite roadbed structure type and a construction method, and belongs to the technical field of roadbed construction, the expansive soil composite roadbed structure type comprises a bottom isolation layer, an expansive soil filling area, an embankment, a roadbed and a pavement, the bottom isolation layer, the expansive soil filling area, the embankment, the roadbed and the pavement are sequentially arranged from bottom to top, and a water seepage pipe is arranged in the expansive soil filling area; the water seepage pipe is laid in the length direction of the roadbed, a water inlet hole is formed in the upper portion of the water seepage pipe, and a water drainage pipe is arranged at the bottom of the water seepage pipe and used for draining accumulated water in the water seepage pipe to the outer side of the roadbed. A blocking piece is arranged in the water seepage pipe and used for blocking the water inlet hole. The method has the effect of improving the roadbed stability.

Description

Technical Field

[0001] The present application relates to the technical field of roadbed construction, and in particular to an expansive soil composite roadbed structure and a construction method. Background Art

[0002] Expansive soil is a kind of highly plastic clay, the main mineral composition of which is montmorillonite, followed by a small amount of clastic minerals such as feldspar, quartz and carbonate. The swelling and water loss shrinkage of expansive soil is mainly caused by the layered structure of montmorillonite, as well as the type and distribution of elements in the structure. Therefore, the higher the content of montmorillonite in the expansive soil, the more prominent its expansion and contraction, disintegration and superconsolidation characteristics. The climate type in the areas where expansive soil is distributed in my country is mainly monsoon climate, with obvious dry and wet seasons, which provides objective conditions for the swelling and water loss shrinkage of expansive soil. As a result, cracks develop in the soil in the expansive soil area as the dry-wet cycle changes, posing a great hidden danger to the stability of the slope roadbed.

[0003] At present, when protecting the expansive soil roadbed, grass protection and skeleton protection are usually used for the slope protection of the expansive soil roadbed, but the grass protection has poor scour resistance, and the skeleton protection is easy to loosen and fall off. Geocell is a new type of high-strength three-dimensional geosynthetics with good durability, integrity and scour resistance, excellent facade reinforcement effect, and better greening effect.

[0004] However, the above-mentioned protective measures are only for the outside of the expansive soil roadbed. When rainwater and other substances penetrate into the interior of the expansive soil, the stability of the roadbed will be greatly reduced. Summary of the invention

[0005] In order to improve the stability of the roadbed, the present application provides an expansive soil composite roadbed structure and a construction method.

[0006] In the first aspect, the present application provides an expansive soil composite roadbed structure, which adopts the following technical solution: An expansive soil composite roadbed structure comprises a bottom isolation layer, an expansive soil filling area, an embankment, a roadbed and a road surface, wherein the bottom isolation layer, the expansive soil filling area, the embankment, the roadbed and the road surface are arranged in sequence from bottom to top, a seepage pipe is arranged in the expansive soil filling area, the seepage pipe is laid along the length direction of the roadbed, a water inlet hole is opened at the top of the seepage pipe, a drainage pipe is arranged at the bottom of the seepage pipe, the drainage pipe is used to discharge the accumulated water in the seepage pipe to the outside of the roadbed; a plugging piece is arranged in the seepage pipe, the plugging piece is used to plug the water inlet hole.

[0007] Optionally, the blocking member includes an elastic plate arranged in the seepage pipe and a plugging head arranged on the elastic plate, the plugging head is used to be inserted into the water inlet hole, the initial state of the elastic plate is parallel to the road surface, the width of the elastic plate is smaller than the diameter of the seepage pipe, the elastic plate is movably arranged in the seepage pipe, the elastic plate moves toward the inner wall of the seepage pipe and fits against the inner wall of the seepage pipe to drive the plugging head to be inserted into the water inlet hole, and the blocking member also includes a first driving member for driving the elastic plate to move.

[0008] Optionally, a mounting frame is provided in the seepage pipe, the middle part of the elastic plate is provided on the mounting frame, the supporting legs of the mounting frame are retractable structures, the supporting legs are fixedly provided on the lower side of the inner wall of the seepage pipe, the retracting direction of the supporting legs is perpendicular to the axial direction of the seepage pipe, and the first driving member is used to drive the supporting legs to retract and retract to drive the elastic plate to move.

[0009] Optionally, the plug has a porous structure and is made of a water-permeable material.

[0010] Optionally, a mounting shaft is rotatably provided on the mounting frame, the length direction and the rotation axis of the mounting shaft are parallel to the length direction of the seepage pipe, the elastic plate is fixedly provided on the mounting shaft on the side away from the water inlet hole, and the mounting frame is provided with a driving motor for driving the mounting shaft to rotate and drive the elastic plate to rotate.

[0011] Optionally, after the plugging head is inserted into the water inlet hole, the tail of the plugging head is located below the horizontal diameter of the seepage pipe.

[0012] Optionally, an isolation plate is arranged between the bottom isolation layer and the expansive soil filling area, the isolation plate is hollow, the drainage pipe is connected to the inner cavity of the isolation plate, a delivery pump is arranged in the isolation plate, and the delivery pump is used to transport the infiltrated water in the isolation plate through the drainage pipe to the seepage pipe, and infiltrate into the expansive soil filling area along the plugging head.

[0013] Optionally, a collecting plate is provided in the embankment, the expansive soil filling area is located below the covering area of ​​the collecting plate, and the collecting plate is hollow and has seepage holes on the top.

[0014] Optionally, a ventilation pipe is provided on the side of the seepage pipe, the length direction of the ventilation pipe is perpendicular to the length direction of the seepage pipe, and the air inlet of the ventilation pipe is located outside the roadbed slope protection.

[0015] In a second aspect, the present application provides a construction method of an expansive soil composite roadbed structure, which adopts the following technical scheme: Optionally, a construction method of an expansive soil composite roadbed structure type, used for constructing an expansive soil composite roadbed structure type, further comprises: S1: Construction of the bottom isolation layer. After the bottom isolation layer reaches the designed strength, an isolation board is built on the bottom isolation layer, and the isolation board is integrally connected to the bottom isolation layer; S2: Loading the expansive soil and spreading it on the isolation board. During the loading process, build a seepage pipe, a drainage pipe and a ventilation pipe. The seepage pipe is laid along the length of the roadbed. The drainage pipe is connected to the seepage pipe and the isolation board. The ventilation pipe is moved out from the side of the expansive soil. S3: Compact the expansive soil. After the expansive soil reaches the designed strength, the collecting plate and embankment, as well as the roadbed and pavement are constructed on the top surface of the expansive soil. S4: Anti-seepage construction, grass planting and skeleton protection are then carried out on the slope of the roadbed.

[0016] In summary, the present application includes at least one of the following beneficial technical effects: 1. After the roadbed construction is completed, when rainwater infiltrates into the expansive soil filling area, the rainwater infiltrates and flows in the expansive soil filling area. When the rainwater infiltrates into the seepage pipe, the rainwater enters the seepage pipe through the water inlet hole and flows along the seepage pipe. When the rainwater flows to the drainage pipe, it is discharged from the roadbed through the drainage pipe. Under the action of the seepage pipe and the drainage pipe, the rainwater infiltrating into the roadbed is quickly discharged, thereby reducing the expansion degree of the expansive soil and reducing the possibility of roadbed damage, thereby improving the stability of the roadbed; 2. When the seepage pipe is buried in the expansive soil, the expansive soil can easily enter the seepage pipe through the water inlet hole and cause the water inlet hole and the seepage pipe to be blocked. Under the action of the blocking piece, the water inlet hole is blocked, thereby reducing the possibility of blockage of the water inlet hole and the seepage pipe, and facilitating the rapid discharge of rainwater, thereby improving the stability of the roadbed. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the overall structure of an expansive soil composite roadbed structure according to an embodiment of the present application; Figure 2 This is a schematic diagram of the structure of a seepage pipe in an expansive soil composite roadbed structure according to an embodiment of the present application; Figure 3 It is a cross-sectional view of an isolation plate in an expansive soil composite roadbed structure according to an embodiment of the present application; Figure 4 It is a schematic diagram of the structure of an elastic plate in an expansive soil composite roadbed structure in an embodiment of the present application.

[0018] Explanation of reference numerals: 1. bottom isolation layer; 2. expansive soil filling area; 3. embankment; 4. roadbed; 5. road surface; 6. seepage pipe; 7. water inlet hole; 8. drainage pipe; 9. Blocking piece; 91. Elastic plate; 92. Blocking head; 93. Electric push rod; 10. Mounting frame; 11. Support legs; 12. Isolation plate; 13. Delivery pump; 14. Mounting shaft; 15. Drive motor; 16. Ventilation pipe; 17. Collecting plate. DETAILED DESCRIPTION

[0019] The following is combined with Figure 1-4 This application is described in further detail.

[0020] The present application embodiment discloses an expansive soil composite roadbed structure. Figure 1 and Figure 2 The expansive soil composite roadbed structure includes a bottom isolation layer 1, an expansive soil filling area 2, an embankment 3, a roadbed 4 and a road surface 5. The bottom isolation layer 1, the expansive soil filling area 2, the embankment 3, the roadbed 4 and the road surface 5 are arranged in sequence from bottom to top. A seepage pipe 6 is arranged in the expansive soil filling area 2. The seepage pipe 6 is laid along the length direction of the roadbed. A water inlet hole 7 is opened on the upper part of the seepage pipe 6. A drainage pipe 8 is arranged at the bottom of the seepage pipe 6. The drainage pipe 8 is used to discharge the accumulated water in the seepage pipe 6 to the outside of the roadbed. After the roadbed construction is completed When rainwater penetrates into the expansive soil filling area 2, the rainwater penetrates and flows in the expansive soil filling area 2. When the rainwater penetrates into the seepage pipe 6, the rainwater enters the seepage pipe 6 through the water inlet hole 7 and flows along the seepage pipe 6. When the rainwater flows to the drainage pipe 8, it is discharged from the roadbed through the drainage pipe 8. Under the action of the seepage pipe 6 and the drainage pipe 8, the rainwater that penetrates into the roadbed is quickly discharged, thereby reducing the expansion degree of the expansive soil and reducing the possibility of roadbed damage, thereby improving the stability of the roadbed.

[0021] Reference Figure 1 and Figure 2 Furthermore, a plugging member 9 is provided in the seepage pipe 6, and the plugging member 9 is used to plug the water inlet hole 7. When the seepage pipe 6 is buried in the expansive soil, the expansive soil is easy to enter the seepage pipe 6 through the water inlet hole 7, and cause the water inlet hole 7 and the seepage pipe 6 to be blocked. Under the action of the plugging member 9, the water inlet hole 7 is blocked, thereby reducing the possibility of blockage of the water inlet hole 7 and the seepage pipe 6, and facilitating the rapid discharge of rainwater, thereby improving the stability of the roadbed.

[0022] Reference Figure 1 and Figure 2In the embodiment of the present application, the plugging member 9 includes an elastic plate 91 arranged in the seepage pipe 6 and a plugging head 92 arranged on the elastic plate 91, the elastic plate 91 is a rubber plate, the plugging head 92 is used to be inserted into the water inlet hole 7, the initial state of the elastic plate 91 is parallel to the road surface 5, the initial state of the elastic plate 91 is a rectangular plate and the length direction is parallel to the length direction of the seepage pipe 6, the width of the elastic plate 91 is smaller than the diameter of the seepage pipe 6, the elastic plate 91 is movably arranged in the seepage pipe 6, the elastic plate 91 moves toward the inner wall of the seepage pipe 6 and fits against the inner wall of the seepage pipe 6 to drive the plugging head 92 to be inserted into the water inlet hole 7, and the plugging member 9 also includes a first driving member for driving the elastic plate 91 to move. When the seepage pipe 6 is buried, under the action of the first driving member, the elastic plate 91 is driven to move, and the elastic plate 91 moves toward the inner wall of the seepage pipe 6. The elastic plate 91 drives the plugging head 92 to move and is inserted into the water inlet hole 7 to block the water inlet hole 7. The operation is simple and convenient. When the water inlet hole 7 is opened, the first driving member drives the elastic plate 91 to drive the plugging head 92 to move toward the axial direction of the seepage pipe 6, so that the plugging head 92 is moved out of the water inlet hole 7.

[0023] Reference Figure 3 and Figure 4 In the embodiment of the present application, a mounting frame 10 is provided in the seepage pipe 6, and the middle part of the elastic plate 91 is provided on the mounting frame 10. The support leg 11 of the mounting frame 10 is a retractable structure, and the support leg 11 is fixedly provided on the lower side of the inner wall of the seepage pipe 6. The retracting direction of the support leg 11 is perpendicular to the axial direction of the seepage pipe 6. The first driving member is used to drive the support leg 11 to retract and drive the elastic plate 91 to move. The first driving member includes an electric push rod 93 provided on the sleeve rod of the support leg 11. The length direction of the output shaft of the electric push rod 93 is parallel to the length direction of the support leg 11. The slide bar of the support leg 11 is fixedly provided on the output shaft of the electric push rod 93. When driving the elastic plate 91 to move, the electric push rod 93 is started, and the output shaft of the electric push rod 93 drives the slide bar to slide, and the slide bar slides to drive the elastic plate 91 to move, and the operation is simple and convenient.

[0024] Reference Figure 3 and Figure 4 In the embodiment of the present application, the plugging head 92 has a porous structure and is made of a water-permeable material; when the amount of rainwater penetration is small, the plugging head 92 is inserted into the water inlet hole 7, and the rainwater penetrates into the seepage pipe 6 through the plugging head 92, and the rainwater is discharged. In the above process, the possibility of rainwater carrying mud and sand into the seepage pipe 6 is reduced, thereby reducing the possibility of blockage of the seepage pipe 6; when the amount of water seepage is large, the plugging head 92 is removed from the water inlet hole 7 to facilitate the rapid discharge of rainwater.

[0025] Reference Figure 2 and Figure 3In the embodiment of the present application, an isolation plate 12 is arranged between the bottom isolation layer 1 and the expansive soil filling area 2. The isolation plate 12 is hollow, and the drainage pipe 8 is connected to the inner cavity of the isolation plate 12. The rainwater in the seepage pipe 6 is collected into the isolation plate 12 through the drainage pipe 8, so as to facilitate the concentrated discharge of the seepage water; further, a delivery pump 13 is arranged in the isolation plate 12, and the delivery pump 13 is connected to the drainage pipe 8. The delivery pump 13 is used to transport the infiltrated water in the isolation plate 12 through the drainage pipe 8 to the seepage pipe 6, and penetrate into the expansive soil filling area 2 along the plug 92; when the water content of the expansive soil drops significantly, the infiltrated water in the isolation plate 12 is extracted by the delivery pump 13 and transported to the seepage pipe 6 through the drainage pipe 8, and then penetrates into the expansive soil through the water inlet hole 7, so as to ensure the water balance of the expansive soil, and then ensure the stability of the roadbed.

[0026] Reference Figure 2 and Figure 3 In the embodiment of the present application, in order to facilitate the infiltration water pumped into the infiltration pipe 6 to infiltrate into the expansive soil through the water inlet hole 7, after the plugging head 92 is inserted into the water inlet hole 7, the tail of the plugging head 92 is located below the horizontal diameter of the infiltration pipe 6. After the delivery pump 13 pumps the infiltration water into the infiltration pipe 6, the tail of the plugging head 92 is immersed below the liquid level of the infiltration water, and the infiltration water infiltrates back into the expansive soil through the plugging head 92, thereby ensuring the water balance of the expansive soil.

[0027] Reference Figure 3 and Figure 4 In the embodiment of the present application, in order to accelerate the evaporation efficiency of rainwater in the expansive soil and maintain the stability of the roadbed, a mounting shaft 14 is rotatably provided on the mounting frame 10, and the length direction and the rotation axis of the mounting shaft 14 are parallel to the length direction of the seepage pipe 6. The elastic plate 91 is fixedly provided on the mounting shaft 14 on the side away from the water inlet hole 7. A driving motor 15 for driving the mounting shaft 14 to rotate and drive the elastic plate 91 to rotate is provided on the mounting frame 10; after the plugging head 92 is driven to separate from the water inlet hole 7 by the electric push rod 93, the elastic plate 91 is placed in a horizontal state, and then the driving motor 15 is started, and the driving motor 15 drives the mounting shaft 14 to rotate, and the rotation of the mounting shaft 14 drives the elastic plate 91 to rotate, and the rotation of the elastic plate 91 accelerates the air flow in the infiltration pipe, thereby accelerating the evaporation efficiency of rainwater in the expansive soil, so as to ensure that the expansive soil recovers the water balance in a short time and improve the stability of the roadbed.

[0028] Reference Figure 1 and Figure 2Furthermore, a ventilation pipe 16 is provided on the side of the seepage pipe 6, the ventilation pipe 16 is connected to the seepage pipe 6, the length direction of the ventilation pipe 16 is perpendicular to the length direction of the seepage pipe 6, and the air inlet of the ventilation pipe 16 is located outside the roadbed slope protection; when the driving motor 15 drives the installation shaft 14 to rotate and drives the elastic plate 91 to rotate, the elastic plate 91 rotates to draw air from the outside of the roadbed into the seepage pipe 6 through the ventilation pipe 16, and then acts on the expansive soil through the water inlet hole 7, further accelerating the water balance of the expansive soil; at the same time, under the action of the seepage pipe 6, the drainage pipe 8 and the ventilation pipe 16, a supporting skeleton is formed in the expansive soil, further improving the stability of the expansive soil.

[0029] Reference Figure 1 In order to reduce the possibility of rainwater infiltrating into the expansive soil through the road surface 5, a collecting plate 17 is provided in the embankment 3. The expansive soil filling area 2 is located below the covering area of ​​the collecting plate 17. The collecting plate 17 is hollow and has a seepage hole on the top.

[0030] The implementation principle of an expansive soil composite roadbed structure in the embodiment of the present application is: After the roadbed construction is completed, when rainwater penetrates into the expansive soil filling area 2, the rainwater penetrates and flows in the expansive soil filling area 2. When the rainwater penetrates to the seepage pipe 6, the rainwater enters the seepage pipe 6 through the water inlet hole 7 and flows along the seepage pipe 6. When the rainwater flows to the drain pipe 8, it is discharged from the roadbed through the drain pipe 8. Under the action of the seepage pipe 6 and the drain pipe 8, the rainwater that penetrates into the roadbed is quickly discharged, thereby reducing the expansion degree of the expansive soil, reducing the possibility of roadbed damage, and thereby improving the stability of the roadbed.

[0031] When the water content of the expansive soil decreases and cracks occur, the seepage water in the isolation plate 12 is extracted by the delivery pump 13 and delivered to the seepage pipe 6 through the drainage pipe 8, and then penetrates into the expansive soil through the water inlet hole 7 to ensure the water balance of the expansive soil and thus ensure the stability of the roadbed.

[0032] The present application embodiment discloses a construction method of an expansive soil composite roadbed structure, which is used to construct an expansive soil composite roadbed structure, and further includes: S1: Construction of the bottom isolation layer 1. After the bottom isolation layer 1 reaches the designed strength, an isolation board 12 is built on the bottom isolation layer 1, and the isolation board 12 is integrally connected to the bottom isolation layer 1; S2: Loading the expansive soil and spreading the expansive soil on the isolation plate 12. During the loading process, a seepage pipe 6, a drainage pipe 8 and a ventilation pipe 16 are built. The seepage pipe 6 is laid along the length of the roadbed. The drainage pipe 8 is connected to the seepage pipe 6 and the isolation plate 12. The ventilation pipe 16 is moved out from the side of the expansive soil. S3: compacting the expansive soil. After the expansive soil reaches the designed strength, a collecting plate 17 and an embankment 3, as well as a roadbed 4 and a road surface 5 are constructed on the top surface of the expansive soil; S4: Anti-seepage construction, grass planting and skeleton protection are then carried out on the slope of the roadbed.

[0033] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. An expansive soil composite roadbed structure, characterized in that: The invention comprises a bottom isolation layer (1), an expansive soil filling area (2), an embankment (3), a roadbed (4) and a road surface (5), wherein the bottom isolation layer (1), the expansive soil filling area (2), the embankment (3), the roadbed (4) and the road surface (5) are arranged in sequence from bottom to top, a water seepage pipe (6) is arranged in the expansive soil filling area (2), the water seepage pipe (6) is laid along the length direction of the roadbed, a water inlet hole (7) is opened at the top of the water seepage pipe (6), a drainage pipe (8) is arranged at the bottom of the water seepage pipe (6), and the drainage pipe (8) is used to discharge the accumulated water in the water seepage pipe (6) to the outside of the roadbed; a plugging member (9) is arranged in the water seepage pipe (6), and the plugging member (9) is used to plug the water inlet hole (7).

2. The expansive soil composite roadbed structure according to claim 1, characterized in that: The plugging member (9) comprises an elastic plate (91) arranged in the seepage pipe (6) and a plugging head (92) arranged on the elastic plate (91); the plugging head (92) is used to be inserted into the water inlet hole (7); the elastic plate (91) is initially parallel to the road surface (5); the width of the elastic plate (91) is smaller than the diameter of the seepage pipe (6); the elastic plate (91) is movably arranged in the seepage pipe (6); the elastic plate (91) moves toward the inner wall of the seepage pipe (6) and fits against the inner wall of the seepage pipe (6) to drive the plugging head (92) to be inserted into the water inlet hole (7); the plugging member (9) further comprises a first driving member for driving the elastic plate (91) to move.

3. The expansive soil composite roadbed structure according to claim 2, characterized in that: A mounting frame (10) is arranged inside the seepage pipe (6), the middle part of the elastic plate (91) is arranged on the mounting frame (10), the supporting leg (11) of the mounting frame (10) is a retractable structure, the supporting leg (11) is fixedly arranged on the lower side of the inner wall of the seepage pipe (6), the retracting direction of the supporting leg (11) is perpendicular to the axial direction of the seepage pipe (6), and the first driving member is used to drive the supporting leg (11) to retract and retract to drive the elastic plate (91) to move.

4. The expansive soil composite roadbed structure according to claim 2, characterized in that: The plug (92) has a porous structure and is made of water-permeable material.

5. The expansive soil composite roadbed structure according to claim 3, characterized in that: The mounting frame (10) is rotatably provided with a mounting shaft (14), the length direction and the rotation axis of the mounting shaft (14) are both parallel to the length direction of the seepage pipe (6), the elastic plate (91) is fixedly provided on the mounting shaft (14) on a side away from the water inlet hole (7), and the mounting frame (10) is provided with a driving motor (15) for driving the mounting shaft (14) to rotate and thereby driving the elastic plate (91) to rotate.

6. The expansive soil composite roadbed structure according to claim 4, characterized in that: After the plugging head (92) is inserted into the water inlet hole (7), the tail of the plugging head (92) is located below the horizontal diameter of the seepage pipe (6).

7. The expansive soil composite roadbed structure according to claim 6, characterized in that: An isolation plate (12) is arranged between the bottom isolation layer (1) and the expansive soil filling area (2); the isolation plate (12) is hollow; the drainage pipe (8) is in communication with the inner cavity of the isolation plate (12); a delivery pump (13) is arranged inside the isolation plate (12); the delivery pump (13) is used to deliver the seepage water in the isolation plate (12) through the drainage pipe (8) to the seepage pipe (6), and to infiltrate into the expansive soil filling area (2) along the plug (92).

8. The expansive soil composite roadbed structure according to claim 6, characterized in that: A collecting plate (17) is arranged inside the embankment (3), the expansive soil filling area (2) is located below the area covered by the collecting plate (17), and the collecting plate (17) is hollow and has a seepage hole on the top.

9. The expansive soil composite roadbed structure according to claim 1, characterized in that: A ventilation pipe (16) is arranged on the side of the seepage pipe (6), the length direction of the ventilation pipe (16) is perpendicular to the length direction of the seepage pipe (6), and the air inlet of the ventilation pipe (16) is located outside the roadbed slope protection.

10. A construction method of an expansive soil composite roadbed structure, used for constructing the expansive soil composite roadbed structure according to any one of claims 1 to 9, characterized in that: Also includes; S1: constructing the bottom isolation layer (1). After the bottom isolation layer (1) reaches the designed strength, an isolation board (12) is built on the bottom isolation layer (1), and the isolation board (12) is integrally connected to the bottom isolation layer (1); S2: Loading the expansive soil and spreading the expansive soil on the isolation plate (12). During the loading process, a seepage pipe (6), a drainage pipe (8) and a ventilation pipe (16) are constructed. The seepage pipe (6) is laid along the length of the roadbed. The drainage pipe (8) is connected to the seepage pipe (6) and to the isolation plate (12). The ventilation pipe (16) is moved out from the side of the expansive soil. S3: compacting the expansive soil. After the expansive soil reaches the designed strength, a collecting plate (17) and an embankment (3), as well as a roadbed (4) and a road surface (5) are constructed on the top surface of the expansive soil. S4: Anti-seepage construction, grass planting and skeleton protection are then carried out on the slope of the roadbed.

Images