Two-stage road pavement structure for unstable roadbed

Abstract

The utility model relates to a two-stage road pavement structure for an unstable roadbed, which is particularly suitable for an unstable area easy to settle and comprises a first-stage pavement structure and a second-stage pavement structure positioned behind the first-stage pavement structure for construction, wherein the first-stage pavement structure is provided with a pre-sedimentation pavement base layer and a prefabricated high-strength concrete interlocking block surface layer, the prefabricated high-strength concrete interlocking block surface layer is arranged on the pre-sedimentation pavement base layer, the second-stage pavement structure comprises a leveling layer and an asphalt surface layer, the leveling layer is located on the prefabricated high-strength concrete interlocking block surface layer, and the asphalt surface layer is located on the leveling layer. And the asphalt surface layer is positioned on the leveling layer. The utility model has the advantages of low manufacturing cost, high bearing capacity, good durability, convenience in construction, easiness in maintenance and replacement and strong adaptability to settlement deformation, and can fully ensure the use of the whole life cycle of the road; subgrade settlement is accelerated; construction is completed in a short time, and the influence on current traffic is small; dismounting and reconstruction are not needed, and resources are saved.

Description

Technical Field

[0001] The utility model relates to the technical field of road construction, in particular to a two-stage road pavement structure for unstable roadbeds, and is particularly suitable for unstable areas prone to settlement. Background Art

[0002] When constructing roads in areas prone to settlement, such as deep soft foundations, blown fill foundations, and coastal areas, the cost of replacing the roadbed is high due to the deep or thick soft base. Generally, consolidation drainage, composite foundations, dynamic compaction, etc. are used for treatment. However, after the implementation of some treatment methods, a long period of time is still required for further preloading or self-settlement to achieve stability.

[0003] Generally speaking, before the roadbed reaches stability, the site is idle and no road paving is carried out. The main problems include: (1) the construction period is increased, and the project construction costs increase; (2) the site is idle for a long time, which has a certain impact on the transportation and land development in the area, and has a greater impact on the regional social and economic development.

[0004] In summary, conventional construction methods have a long construction period and a long idle time of the roadbed, which has a negative impact on the economy and society. Therefore, a new road implementation method needs to be designed to solve the above problems. Summary of the invention

[0005] The purpose of the utility model is to provide a two-stage road pavement structure for unstable roadbed in accordance with the above-mentioned deficiencies of the prior art, which provides safe traffic conditions through a first-stage pavement structure that is constructed in advance and has strong deformation adaptability to roadbed settlement. After the roadbed settlement reaches stability, there is no need to dig up the original pavement structure, and the second-stage pavement construction is directly carried out on the basis of the first-stage pavement structure to eventually form a permanent road. The time from the initial stable state to the stable state of the roadbed settlement is fully utilized to open to traffic in advance, and the two pavement structure constructions do not involve demolition and reconstruction.

[0006] The purpose of this utility model is achieved by the following technical solutions:

[0007] A two-stage road pavement structure for an unstable roadbed is arranged on the roadbed, and is characterized in that it includes a first-stage pavement structure and a second-stage pavement structure constructed thereafter, wherein the first-stage pavement structure has a pre-settlement pavement base layer and a prefabricated high-strength concrete interlocking block surface layer, and the prefabricated high-strength concrete interlocking block surface layer is arranged on the pre-settlement pavement base layer; the second-stage pavement structure includes a leveling layer and an asphalt surface layer, the leveling layer is located on the prefabricated high-strength concrete interlocking block surface layer, and the asphalt surface layer is located on the leveling layer.

[0008] An asphalt crushed stone seal layer and a medium-coarse sand cushion layer are arranged in sequence from bottom to top between the pre-settled pavement base layer and the prefabricated high-strength concrete interlocking block surface layer.

[0009] A geotextile is arranged between the prefabricated high-strength concrete interlocking block surface layer and the leveling layer.

[0010] The prefabricated high-strength concrete interlocking blocks of the prefabricated high-strength concrete interlocking block surface layer are sealed by an emulsified asphalt sealing layer.

[0011] The advantages of the utility model are:

[0012] (1) Before the roadbed reaches stability, a time node is selected in advance to carry out pre-settlement pavement construction. The pre-settlement pavement can not only be used as a road opened to traffic in advance, but also as a part of the permanent pavement structure, thus maximizing and accelerating the economic and social benefits;

[0013] (2) The pre-settlement pavement surface layer is paved with prefabricated high-strength interlocking blocks, which not only has low cost, high bearing capacity, good durability, and convenient construction, but can fully guarantee the use of the road throughout its life cycle. It is also easy to repair and replace, and has strong adaptability to settlement and deformation;

[0014] (3) The first stage of the road surface can accelerate the settlement of the roadbed by vehicle load, which is less costly than the conventional loading preloading method and faster than the self-settlement method;

[0015] (4) The second-stage pavement structure is mainly made of asphalt and is paved directly on the first-stage pavement structure. The construction can be completed in a short period of time and has little impact on existing traffic. When the second stage is implemented, the first-stage pavement structure does not need to be demolished and renovated, which saves resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a cross-sectional view of the pavement structure of the first stage in the utility model;

[0017] Figure 2 This is a cross-sectional view of the second stage pavement structure in the utility model. DETAILED DESCRIPTION

[0018] The following is a further detailed description of the features of the present invention and other related features through embodiments in conjunction with the accompanying drawings to facilitate understanding by technicians in the same industry:

[0019] like Figure 1-2 As shown in the figure, marks 1-9 respectively represent: roadbed 1, pre-settled pavement base 2, asphalt crushed stone seal layer 3, medium-coarse sand cushion layer 4, prefabricated high-strength concrete interlocking block surface layer 5, interlocking block surface layer emulsified asphalt filling layer 6, geotextile 7, leveling layer 8, asphalt surface layer 9.

[0020] Example: Figure 1 and Figure 2 As shown, before the roadbed settlement is stable, this embodiment selects the roadbed in a preliminary stable state that meets the traffic conditions to carry out the first stage of pavement structure construction. On the one hand, it can provide safe traffic conditions as early as possible, and on the other hand, it allows the pavement structure to have a certain degree of overall settlement with the roadbed; after the roadbed settlement reaches stability, there is no need to dig up the original pavement structure, and the second stage of pavement paving construction is directly carried out on the basis of the first stage pavement structure, and finally a permanent road is formed. Compared with the conventional construction method, the present invention makes full use of the time from the initial stable state of the roadbed settlement to the stable state to open to traffic in advance, and the two pavement structure constructions do not involve demolition and reconstruction.

[0021] like Figure 1 As shown in the figure, the first-stage pavement structure (pre-settlement pavement structure) in this embodiment can be implemented after the roadbed settlement is initially stabilized. The first-stage design content is as follows: (1) The roadbed compaction, top surface rebound modulus and other technical indicators must meet the permanent road design requirements and specification requirements; (2) The pavement structure mainly includes the base layer, seal layer, cushion layer and surface layer from bottom to top; (3) The base layer thickness and material selection are designed according to the permanent road grade and predicted traffic volume, and comply with the "Highway Asphalt Pavement Design Specification" (JTG D50) and other specification requirements; if the road is in a section with poor temperature and humidity conditions, a cushion layer of not less than 150 mm can be set under the base layer.

[0022] Specifically, if Figure 1 As shown, the base layer in this embodiment adopts a pre-settled pavement base layer 2, which is arranged on the roadbed 1; the sealing layer adopts a 10mm asphalt crushed stone sealing layer 3; the cushion layer adopts a 30mm medium-coarse sand cushion layer 4; the surface layer adopts 100mm prefabricated high-strength concrete (C60) interlocking blocks assembled to form a prefabricated high-strength concrete interlocking block surface layer 5. The prefabricated high-strength concrete interlocking blocks are simple and quick to construct, low in cost, have strong adaptability to deformation caused by roadbed settlement, and are easy to repair damaged pavement before the implementation of the second stage pavement structure.

[0023] In this embodiment, steps are excavated from bottom to top of the old roadbed at the junction of the new and old roads for overlap. In order to reduce reflective cracks and uneven settlement, geogrids are laid between the base layers when joining the old road.

[0024] like Figure 2As shown in the figure, the second-stage pavement structure (additional pavement structure) is implemented after the roadbed settlement reaches stability. The design contents of the second stage are as follows: (1) Replace and repair the damaged prefabricated high-strength interlocking blocks in the prefabricated high-strength concrete interlocking block surface layer 5, clean the interlocking block surface layer and keep it dry; (2) Use emulsified asphalt to fill the joints of the prefabricated interlocking pavement, spray tack coat asphalt to form an emulsified asphalt filling layer 6 of the interlocking block surface layer, and lay geotextile 7 over the entire width; (3) According to the pavement settlement and the height difference between the surrounding roads and plots, lay the leveling layer 8. If the height difference is small, the lower layer can be used as the leveling layer 8; if the height difference is large, asphalt crushed stone, asphalt stabilized penetration crushed stone, etc. can be used as the leveling layer 8; (4) According to the road grade and predicted traffic volume, lay the asphalt surface layer 9. In principle, the surface layer should be set at least 2 layers, in accordance with the "Highway Asphalt Pavement Design Specification" (JTG D50) and other regulatory requirements; (5) When the road is connected with the intersecting road or the entrance and exit of the plot, in order to reduce reflective cracks and uneven settlement, a layer of geogrid is laid between the road leveling layer and the intersecting road or the entrance and exit base layer.

[0025] Although the above embodiments have described the concepts and embodiments of the purpose of the utility model in detail with reference to the accompanying drawings, ordinary technicians in this field can recognize that various improvements and modifications can still be made to the utility model without departing from the scope of the claims, so they are not described one by one here.

Claims

1. A two-stage road pavement structure for an unstable roadbed, arranged on the roadbed, characterized in that: The invention comprises a first-stage pavement structure and a second-stage pavement structure constructed thereafter, wherein the first-stage pavement structure comprises a pre-settled pavement base layer and a prefabricated high-strength concrete interlocking block surface layer, wherein the prefabricated high-strength concrete interlocking block surface layer is arranged on the pre-settled pavement base layer, and the second-stage pavement structure comprises a leveling layer and an asphalt surface layer, wherein the leveling layer is located on the prefabricated high-strength concrete interlocking block surface layer, and the asphalt surface layer is located on the leveling layer.

2. A two-stage road pavement structure for an unstable roadbed according to claim 1, characterized in that: An asphalt crushed stone seal layer and a medium-coarse sand cushion layer are arranged in sequence from bottom to top between the pre-settled pavement base layer and the prefabricated high-strength concrete interlocking block surface layer.

3. A two-stage road pavement structure for an unstable roadbed according to claim 1, characterized in that: A geotextile is arranged between the prefabricated high-strength concrete interlocking block surface layer and the leveling layer.

4. A two-stage road pavement structure for an unstable roadbed according to claim 1 or 3, characterized in that: The prefabricated high-strength concrete interlocking blocks of the prefabricated high-strength concrete interlocking block surface layer are sealed by an emulsified asphalt sealing layer.

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