Highway subgrade structure capable of preventing subgrade softening and capable of cooling asphalt pavement

Abstract

The application discloses a highway subgrade structure capable of preventing subgrade softening and cooling asphalt pavement, which comprises a roadbed, a sandstone layer and an asphalt pavement layer arranged in sequence from bottom to top, wherein the roadbed is located on a foundation, the two sides of the roadbed, the sandstone layer and the asphalt pavement layer are embankments respectively, a plurality of water guide grooves are arranged in the sandstone layer along the line of the highway at intervals, the water guide grooves are arranged along the width direction of the highway, the two ends of the water guide grooves are respectively connected with downwardly inclined water outlet grooves, the tail ends of the water outlet grooves are connected with a drainage system located in the embankment, low partition plates are vertically arranged at the two ends of the water guide grooves to form water storage grooves in the lower part of the water guide grooves, a first water absorption layer is arranged on the bottom of the water storage grooves, sandstone support plates are horizontally arranged on the upper part of the water guide grooves and the water outlet grooves, a plurality of water filtering holes are arranged on the sandstone support plates at intervals, a second water absorption layer is horizontally arranged in the sandstone layer above the two adjacent water guide grooves, and the two sides of the second water absorption layer are respectively connected with the first water absorption layers in the two adjacent water guide grooves through a plurality of water absorption strips arranged at intervals.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of roadbeds, in particular to a highway roadbed structure capable of preventing roadbed softening and cooling asphalt pavement. BACKGROUND

[0002] A roadbed is the foundation of a track or a road surface, and is a soil engineering structure formed by excavation or filling. The main role of a roadbed is to provide necessary conditions for track or road surface laying and train or vehicle operation, and to bear static and dynamic loads of tracks and vehicles or road surfaces and traffic, and to transmit and diffuse the loads to the deep foundation. On the longitudinal section, the roadbed must ensure the elevation required by the line, and on the plane, the roadbed and the bridge and tunnel form an integrated and continuous line. In civil engineering, roadbeds play an important role in terms of construction quantity, land area and investment, and a highway roadbed is one of many roadbeds.

[0003] A highway roadbed structure capable of preventing roadbed softening is disclosed in Chinese Patent No. CN111455755B, which comprises a bottom layer, a first reinforcing layer comprising a first reinforcing net laid on the bottom layer and a cement mortar layer formed by pouring cement mortar on the first reinforcing net, a softening prevention layer comprising a fixed grid net, a composite water filtering layer and a water outlet pipe, the fixed grid net being connected with the first reinforcing net through support columns on the first reinforcing net, the composite water filtering layer being composed of water guide blocks, coarse sand layers and fine sand layers from bottom to top, the water outlet pipe comprising branch water outlet pipes connected with water filtering holes of the water guide blocks and a main water outlet pipe connecting the branch water outlet pipes, the main water outlet pipe extending out of the roadbed from the side of the roadbed, a second reinforcing layer, a road surface layer arranged above the second reinforcing layer, and the road surface layer comprising a base layer and a surface layer from bottom to top. The roadbed structure with multiple layers can not only increase the strength of the roadbed, but also has good drainage performance, effectively preventing roadbed softening.

[0004] According to the related technology in the above, the inventors believe that the following defects exist: The existing roadbed softening prevention usually uses a water outlet pipe to quickly guide the water in the roadbed to the outside of the roadbed, reducing the water content in the roadbed to prevent softening of the roadbed. However, the water resource cannot be effectively utilized by using the water outlet pipe, and in addition, the asphalt pavement laid will soften under high temperature weather, which can easily cause the road surface to have pits and hollows. SUMMARY

[0005] Therefore, the present application aims to provide a highway roadbed structure capable of preventing roadbed softening and cooling asphalt pavement, which solves the technical problem of ineffective utilization of water resources by using a water outlet pipe for roadbed softening prevention and softening of asphalt pavement under high temperature weather.

[0006] The purpose of the present application is achieved by the following technical solutions:

[0007] The highway subgrade structure capable of preventing subgrade softening and cooling asphalt pavement includes a roadbed, a sand layer and an asphalt pavement layer arranged in sequence from bottom to top, the roadbed is located on a foundation, both sides of the roadbed, sand layer and asphalt pavement layer are embankments, a plurality of water guide grooves are arranged in the sand layer along the line of the highway, the water guide grooves are arranged along the width direction of the highway, both ends of the water guide grooves are respectively connected with downwardly inclined water outlet grooves, the ends of the water outlet grooves are connected with a drainage system located in the embankment, low partitions are vertically arranged at both ends of the water guide grooves to form water storage grooves in the lower part of the water guide grooves, a first water absorption layer is arranged at the bottom of the water storage grooves, sand support plates are horizontally arranged at the upper part of the water guide grooves and water outlet grooves, a plurality of water filtering holes are arranged in the sand support plates, a second water absorption layer is arranged in the sand layer above the adjacent two water guide grooves, and the second water absorption layer is connected with the first water absorption layers in the adjacent two water guide grooves through a plurality of water absorption strips arranged at intervals.

[0008] Further, a waterproof layer is arranged between the roadbed and the sand layer.

[0009] Further, the drainage system includes longitudinal drainage grooves arranged along the line of the highway, transverse drainage pipes are connected to the longitudinal drainage grooves at intervals, and the other ends of the transverse drainage pipes are located outside the embankment.

[0010] Further, the water guide grooves and the water outlet grooves are inverted trapezoidal grooves.

[0011] Further, the sand support plates are supported by a plurality of trousers-type support pieces arranged at intervals along the length direction of the sand support plates, the top of the trousers-type support pieces is connected with the sand support plates, and the two free ends of the bottom of the trousers-type support pieces are respectively connected with both sides of the water guide grooves or both sides of the water outlet grooves.

[0012] Further, the water absorption strips and the second water absorption layer are connected through a connecting piece, the connecting piece is U-shaped, the two free ends of the connecting piece are respectively connected with the second water absorption layer, and the end of the water absorption strip is wound on the U-shaped connecting piece.

[0013] The beneficial effects of the present application are:

[0014] The highway subgrade structure of the application can prevent subgrade softening and can cool asphalt pavement, water seepage from sand and stone layer and asphalt pavement layer above the water guide groove is directly accepted by the water guide groove, water seepage from the sand and stone layer and asphalt pavement layer above two adjacent water guide grooves is guided into the water guide groove by the second water absorption layer, water absorption strip and the first water absorption layer, when the water seepage accepted by the water guide groove is too much, the overflow is discharged through the drainage system via the water outlet groove, the water seepage in the subgrade is quickly guided out, the water seepage into the roadbed is effectively avoided, and thus the softening caused by the increase of water content in the subgrade is effectively improved; the water seepage in the asphalt pavement and the second water absorption layer is quickly evaporated under high temperature, the second water absorption layer quickly absorbs water from the water storage groove through the water absorption strip and the first water absorption layer to maintain a certain humidity, and thus the heating rate of the asphalt pavement is effectively relieved, and the high temperature softening of the asphalt pavement layer is avoided.

[0015] Other advantages, objects, and features of the application will be better understood from the following specification and claims, and will be more fully appreciated when the same is considered in conjunction with the accompanying drawings. The objects and other advantages of the application will be realized and attained by the structure particularly pointed out in the specification and claims. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to make the objects, technical solutions and advantages of the application clearer, the following will further describe the application in detail with reference to the accompanying drawings, in which:

[0017] Figure 1 is a sectional view of the application.

[0018] Figure 2 is a perspective view of the water guide groove, water outlet groove, gravel support plate, first water absorption layer, water absorption strip and second water absorption layer in the application.

[0019] Figure 3 is a top view of the water guide groove, water outlet groove, gravel support plate, first water absorption layer, water absorption strip and second water absorption layer in the application.

[0020] Figure 4 is Figure 3 A-A sectional view in the figure.

[0021] Figure 5 is Figure 3 B-B sectional view in the figure.

[0022] In the figure: roadbed 1, sand and stone layer 2, asphalt pavement layer 3, foundation 4, embankment 5, water guide groove 6, water outlet groove 7, low partition plate 8, water storage groove 9, first water absorption layer 10, sand and stone support plate 11, water filter hole 12, second water absorption layer 13, water absorption strip 14, waterproof layer 15, longitudinal drainage groove 16, connecting piece 17, transverse drainage pipe 18, trousers type support sheet 19. DETAILED DESCRIPTION

[0023] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be understood that the preferred embodiments are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.

[0024] like Figures 1-5 As shown, the highway subgrade structure, which can prevent subgrade softening and cool asphalt pavement, includes a roadbed 1, a gravel layer 2, and an asphalt pavement layer 3 arranged sequentially from bottom to top. The roadbed 1 is located on the foundation 4. Embankments 5 are located on both sides of the roadbed 1, gravel layer 2, and asphalt pavement layer 3. Several drainage channels 6 are spaced along the highway within the gravel layer 2, extending along the width of the highway. Both ends of the drainage channels 6 are connected to downwardly inclined drainage channels 7. The ends of the drainage channels 7 are connected to a drainage system located within the embankments 5. The drainage channels 6 are vertically inclined at both ends along their width. A low partition 8 is provided to form a water storage tank 9 at the bottom of the water guide trough 6. A first absorbent layer 10 is laid at the bottom of the water storage tank 9. A sand and gravel support plate 11 is horizontally provided above the water guide trough 6 and the lower water trough 7. There is a gap between the sand and gravel support plate 11 and the top of the water storage tank 9. Several filter holes 12 are provided on the sand and gravel support plate 11 at intervals. A second absorbent layer 13 is laid flat in the sand and gravel layer 2 above two adjacent water guide troughs. The two sides of the second absorbent layer 13 are connected to the first absorbent layer 10 in the two adjacent water guide troughs by several spaced absorbent strips 14. The absorbent strips 14 penetrate the sand and gravel support plate 11. Preferably, the first absorbent layer 10, the absorbent strips 14 and the second absorbent layer 13 are made of cotton or linen.

[0025] When it rains, rainwater seeps through the asphalt pavement layer 3 into the gravel layer 2, and then falls onto the second absorbent layer 13 and the drainage channel 6. The second absorbent layer 13 guides the water into the drainage channel 6 through the absorbent strips 14 and the first absorbent layer 10, increasing the drainage area. The drainage channel 6 can catch a large area of ​​rainwater. The drainage channel 6 allows the water to pass through the drain trough 7 and be discharged into the drainage system, effectively preventing rainwater from seeping into the roadbed 1 and foundation 4, and preventing the roadbed 1 and foundation 4 from softening and settling. At the same time, the lower part of the drainage channel 6 is formed by two low partitions 8 to form a water storage tank 9 to store some water. Excess water overflows and is discharged from the drain trough 7. The water stored in the water storage tank 9 passes through the first absorbent layer 13. The water-absorbing strip 14 and the first water-absorbing layer 10 can conduct water to the second water-absorbing layer 13. In hot weather, the moisture in the asphalt pavement layer 3 evaporates rapidly. The second water-absorbing layer 13, located below the asphalt pavement layer 3, also experiences rapid moisture evaporation. The second water-absorbing layer 13 absorbs moisture from the water storage tank 9 through the water-absorbing strip 14 and the first water-absorbing layer 10, keeping the second water-absorbing layer 13 moist. This ensures that the upper aggregate maintains a certain level of humidity, effectively mitigating the heating rate of the asphalt pavement layer 3 and preventing it from softening at high temperatures. Therefore, this structure not only protects the roadbed from water softening but also ensures heat dissipation of the asphalt pavement layer 3 in hot weather, preventing road surface deformation at high temperatures. The drainage trough allows water seeping into the pavement to be quickly and stably channeled into the drainage system.

[0026] The aforementioned waterproof layer 15 is laid between the roadbed 1 and the gravel layer 2, and the waterproof layer 15 is a waterproof roll material, which further improves the waterproof performance of the roadbed 1 and prevents the remaining water from seeping into the roadbed 1.

[0027] The drainage system comprises longitudinal drainage channels 16 arranged along the highway, and the longitudinal drainage channels 16 are connected with transverse drainage pipes 18 at intervals, and the other ends of the transverse drainage pipes 18 are located outside the embankment. The longitudinal drainage channels 16 are top-closed channels, and the water storage tank 9 in the water guide channel 6 is filled with water. When the water overflows, the water flows into the longitudinal drainage channels 16 through the downcomer 7 and is discharged outside the embankment 5 through the transverse drainage pipes 18.

[0028] The water guide channel 6 and the downcomer 7 are inverted trapezoidal channels, and the outer side of the water guide channel 6 is tightly combined with the gravel of the gravel layer 2, and has good supporting performance.

[0029] The gravel support plate 11 is supported by a plurality of trousers-type support pieces 19 arranged at intervals along the length direction of the gravel support plate 11. The top of the trousers-type support piece 19 is connected with the gravel support plate 11, and the two free ends of the bottom of the trousers-type support piece 19 are connected with the two sides of the water guide channel 6 or the two sides of the downcomer 7. The two sides of the gravel support plate 11 are combined with the two sides of the water guide channel 6 or the downcomer 7 and are supported by a plurality of trousers-type support pieces 19, which can effectively support the gravel above. The water guide channel 6, the downcomer 7, the trousers-type support piece 19, the low partition plate 8 and the gravel support plate 11 are made of rust-proof steel material.

[0030] The water absorption strip 14 is connected with the second water absorption layer 13 through a connecting piece 17, the connecting piece 17 is U-shaped, and the two free ends of the connecting piece 17 are connected with the second water absorption layer 13. The end of the water absorption strip 14 is wound on the U-shaped connecting piece 17, and the connecting piece 17 is made of cotton material or linen material.

[0031] Finally, it should be pointed out that the above embodiments are only used to illustrate the technical solutions of the present application and are not limiting. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced equivalently without departing from the purpose and scope of the technical solutions, and all of them should be covered in the scope of the claims of the present application.

Claims

1. A highway subgrade structure capable of preventing subgrade softening and cooling asphalt pavement, comprising, from bottom to top, a roadbed (1), a sand and gravel layer (2) and an asphalt pavement layer (3), wherein the roadbed (1) is located on a foundation (4), and both sides of the roadbed (1), the sand and gravel layer (2) and the asphalt pavement layer (3) are embankments (5), characterized in that: The sand layer (2) is provided with a plurality of water guide grooves (6) along the highway, the water guide grooves (6) are arranged along the width direction of the highway, the two ends of the water guide grooves (6) are respectively connected with downwardly inclined water outlet grooves (7), the ends of the water outlet grooves (7) are connected with a drainage system in the embankment (5), the water guide grooves (6) are respectively provided with low partitions (8) at the two ends to form water storage grooves (9) at the lower part of the water guide grooves (6), the water storage grooves (9) are provided with first water absorption layers (10) on the bottom, the upper part of the water guide grooves (6) and the water outlet grooves (7) are horizontally provided with sand support plates (11), the sand support plates (11) are provided with a plurality of water filtering holes (12) at intervals, the sand layer (2) above the two water guide grooves (6) is provided with second water absorption layers (13) arranged horizontally, the two sides of the second water absorption layers (13) are respectively connected with the first water absorption layers (10) in the two water guide grooves through a plurality of water absorption strips (14) arranged at intervals; ​ The roadbed (1) and the sand layer (2) are provided with a waterproof layer (15) therebetween; The drainage system comprises longitudinal drainage grooves (16) arranged along the highway, the longitudinal drainage grooves (16) are provided with transverse drainage pipes (18) connected at intervals, and the other ends of the transverse drainage pipes are located outside the embankment; The water guide grooves (6) and the water outlet grooves (7) are inverted trapezoidal grooves; The sand support plates (11) are supported by a plurality of trousers-type support pieces (19) arranged at intervals along the length direction of the sand support plates (11), the top of the trousers-type support pieces (19) is connected with the sand support plates (11), and the two free ends of the bottom of the trousers-type support pieces (19) are respectively connected with the two sides of the water guide grooves (6) or the two sides of the water outlet grooves (7); The water absorption strips (14) and the second water absorption layers (13) are connected through connecting pieces (17), the connecting pieces (17) are U-shaped and the two free ends of the connecting pieces (17) are respectively connected with the second water absorption layers (13), and the ends of the water absorption strips (14) are wound on the U-shaped connecting pieces (17).

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