Roadbed and pavement structure with synergetic deformation

Abstract

The utility model belongs to the technical field of road engineering, and particularly relates to a deformation collaborative roadbed and pavement structure. The roadbed and pavement structure comprises a soft soil foundation, retaining walls located on the two sides of a road on the soft soil foundation and a full-flexible asphalt pavement layer. A steel bar support is embedded in the soft soil foundation, and the two ends of the steel bar support are rigidly connected with the retaining walls on the two sides. A cement treatment soil replacing and filling layer is arranged between the steel bar bracket and the surface of the soft soil foundation; the full-flexible asphalt pavement layer sequentially comprises a lower base layer, an upper base layer, a lower surface layer, a middle surface layer and a surface layer from bottom to top; wherein a layer of reinforcing mesh is arranged in the lower base layer, and the reinforcing mesh is rigidly connected with the retaining walls on the two sides; and a layer of glass fiber grating is laid between the middle surface layer and the lower surface layer. Dynamic coordination of foundation deformation and pavement structure response is achieved by constructing a'retaining wall-steel bar support-flexible pavement layer 'ternary coupling structure system.

Description

Technical Field

[0001] This utility model belongs to the technical field of road engineering, specifically relating to a deformation-coordinated roadbed and pavement structure. Background Technology

[0002] Soft soil subgrade refers to a roadbed constructed on soft soil foundations. Soft soil foundations are characterized by high natural water content, high compressibility, and low shear strength, which can easily lead to uneven subgrade settlement and reflective cracking in road engineering. Therefore, the treatment and construction of soft soil subgrades require special attention to ensure their stability and bearing capacity. Traditional soft soil subgrade treatment techniques commonly use methods such as replacement, preloading and drainage, and pile foundation reinforcement. However, these methods all suffer from drawbacks such as long construction periods, poor economic efficiency, and significant environmental impact.

[0003] Currently, existing pavement structures suffer from ineffective deformation coordination with soft soil subgrades, leading to stress concentration, cracks, and uneven settlement, which in turn affects the safety and durability of road engineering. For example, rigid pavement structures struggle to adapt to the rheological characteristics of soft soil subgrades, easily causing stress concentration and structural failure. While conventional flexible pavements possess some deformation capacity, the lack of a coordinated deformation mechanism between the pavement base and the soft soil subgrade makes it difficult to effectively control post-construction settlement. In particular, existing retaining wall structures are mostly used as independent support systems, failing to form an integrated load-bearing system with the pavement structure, resulting in discontinuous load transfer paths and hindering the full utilization of confining pressure effects.

[0004] Existing technologies propose using composite foundation reinforcement methods, combining multiple foundation treatment techniques to improve foundation bearing capacity, reduce settlement, and enhance overall foundation performance. For example, surcharge preloading or vacuum preloading can be used to accelerate the consolidation settlement of soft soil, while pile foundations are driven in after preloading to further increase bearing capacity. While this can improve bearing capacity to some extent, it significantly increases construction complexity and project costs, severely limiting its effectiveness in deep soft soil areas. Utility Model Content

[0005] The purpose of this invention is to address the technical bottlenecks in soft soil foundation road construction, such as poor structural coordination and difficulty in post-construction settlement control, by proposing an integrated roadbed and pavement structure system based on a deformation coordination mechanism. By constructing a ternary coupled structure system of "retaining wall-reinforced steel support-flexible pavement layer," dynamic coordination between foundation deformation and pavement structural response is achieved.

[0006] The technical solution of this utility model is as follows:

[0007] A deformation-coordinated roadbed and pavement structure includes a soft soil foundation, retaining walls on both sides of the road located on the soft soil foundation, and a fully flexible asphalt pavement layer. The fully flexible asphalt pavement layer is a pavement layer composed entirely of asphalt mixture, with each layer using asphalt mixture, exhibiting strong fatigue resistance and deformation resistance.

[0008] A steel reinforcement frame is embedded inside the soft soil foundation, and the two ends of the steel reinforcement frame are rigidly connected to the retaining walls on both sides.

[0009] The space between the steel reinforcement support and the soft soil foundation surface is a cement-treated soil replacement layer. A 6% cement-treated soil layer is used for replacement on top of the steel reinforcement support, which satisfies the roadbed bearing capacity and works synergistically with the steel reinforcement support.

[0010] The fully flexible asphalt pavement consists of, from bottom to top, a lower base course, an upper base course, a lower surface layer, an intermediate surface layer, and a surface layer. This layered design from bottom to top achieves stress redistribution, greatly reducing pavement cracking.

[0011] The lower base layer is equipped with a steel mesh, which is rigidly connected to the retaining walls on both sides.

[0012] A layer of fiberglass geogrid is laid between the intermediate layer and the lower layer. Laying a layer of fiberglass geogrid can absorb interlayer shear stress and tensile stress, reduce stress concentration at crack tips, delay crack initiation and development, and work with other structures to improve the pavement structure's ability to deform together.

[0013] Furthermore, in the aforementioned deformation-coordinated roadbed and pavement structure, the upper surface of the retaining wall is on the same horizontal plane as the upper surface of the lower base course in the fully flexible asphalt pavement layer. This provides lateral support for the cast-in-place asphalt concrete construction of the lower base course and enables the lateral diffusion of vertical loads; it also achieves coordinated deformation with the fully flexible asphalt pavement layer.

[0014] Furthermore, the deformation-coordinated roadbed and pavement structure has a steel reinforcement support of 1m×1m-3m×3m steel mesh.

[0015] Furthermore, in the aforementioned deformable roadbed and pavement structure, the reinforcing bars of the steel reinforcement support are made of threaded steel with a diameter of 12mm.

[0016] Furthermore, in the aforementioned deformation-coordinated roadbed and pavement structure, the steel reinforcement support is embedded 25-30 cm below the surface of the soft soil foundation. Embedding the steel reinforcement support within this location range satisfies the requirements for coordinated deformation without significantly increasing construction costs.

[0017] Furthermore, in the aforementioned deformation-coordinated roadbed and pavement structure, the steel mesh installed inside the lower base layer is 2-3 cm away from the surface of the soft soil foundation. The steel mesh is embedded precisely in the middle of the cast-in-place asphalt concrete layer of the lower base layer, enabling it to work in synergy with the cast-in-place asphalt concrete to achieve increased stiffness, lateral load diffusion, and coordinated deformation.

[0018] Furthermore, in the aforementioned deformable roadbed and pavement structure, the mesh size of the steel mesh is 100mm×100mm-200mm×200mm.

[0019] Furthermore, in the aforementioned deformable roadbed and pavement structure, the diameter of the reinforcing steel mesh is 8mm.

[0020] Furthermore, in the aforementioned deformable roadbed and pavement structure, the thickness of the lower base layer in the fully flexible asphalt pavement layer is 3-5cm; the thickness of the upper base layer is 6-8cm; the thickness of the lower layer is 6-10cm; the thickness of the middle layer is 4-8cm; and the thickness of the surface layer is 1.5-2.5cm.

[0021] The total thickness of the fully flexible pavement layer is at most 33.5cm. It can be seen that, according to the design of the roadbed and pavement structure, the fully flexible pavement layer can achieve a thinner total thickness while meeting the pavement performance design requirements. This can reduce the self-weight and reduce the impact on the bearing capacity of the soft soil subgrade.

[0022] The beneficial effects of this utility model are as follows: Compared with the prior art, the soft soil foundation in the deformation-coordinated roadbed and pavement structure of this utility model can significantly improve the coordinated deformation capacity without special treatment, eliminating the traditional deep treatment process for soft soil foundation, shortening the construction cycle and reducing construction costs.

[0023] The specific explanation is as follows: First, the retaining walls on both sides play a role in containing the soil pressure; at the same time, a three-dimensional steel reinforcement frame is set inside the soft soil foundation and rigidly welded to the cast-in-place reinforced concrete retaining walls on both sides to form an overall load-bearing frame of foundation-retaining wall, thereby improving the bearing capacity of the soft soil foundation; and a steel mesh is set in the base layer of the fully flexible asphalt pavement and welded to the pre-embedded parts at the top of the retaining wall to achieve the lateral diffusion of vertical loads and achieve coordinated deformation with the fully flexible asphalt pavement.

[0024] In summary, the steel reinforcement support in the soft soil foundation and the steel mesh at the bottom of the fully flexible asphalt pavement layer in the roadbed and pavement structure described in this utility model form an integral whole with the retaining wall. Working in synergy with the fully flexible asphalt pavement layer, it can deform in synergy under load and environmental factors, exhibiting excellent synergistic deformation capacity. This significantly improves the stability of roads on soft soil foundations, avoids uneven settlement and reduces pavement damage, effectively increases the service life and safety of highways, and greatly reduces the total life cycle cost. It can be widely applied to highway construction in soft soil foundation areas. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the roadbed and pavement structure described in the embodiments of this utility model.

[0026] Among them, 1 is the retaining wall, 2 is the cement treatment soil replacement layer, 3 is the upper base layer, 4 is the lower base layer, 5 is the middle layer, 6 is the surface layer, 7 is the fiberglass grid, 8 is the lower base layer, 9 is the steel mesh, 10 is the steel support, and 11 is the soft soil foundation. Detailed Implementation

[0027] The technical solution of this utility model will now be described in detail with reference to the accompanying drawings.

[0028] Example 1

[0029] This structure was implemented in a coastal soft soil area.

[0030] The deformation-coordinated roadbed and pavement structure includes a soft soil foundation 11, retaining walls 1 on both sides of the road located on the soft soil foundation 11, and a fully flexible asphalt pavement layer.

[0031] A steel reinforcement support 10 is embedded 30cm below the surface of the soft soil foundation 11. The steel reinforcement support 10 is a 2m×2m steel mesh. The steel bars are 12mm diameter threaded steel. The two ends of the steel reinforcement support 10 are rigidly connected to the retaining walls 1 on both sides.

[0032] The space between the steel reinforcement support 10 and the surface of the soft soil foundation 11 is a cement-treated soil replacement layer 2.

[0033] The fully flexible asphalt pavement layer consists of, from bottom to top, a 4cm thick lower base layer 8, a 6cm thick upper base layer 3, an 8cm thick lower layer 4, a 6cm thick middle layer 5, and a 2cm thick surface layer 6. The upper surface of the retaining wall 1 is on the same horizontal plane as the upper surface of the lower base layer 8.

[0034] The lower layer 8 contains a steel mesh 9, which is rigidly connected to the retaining walls 1 on both sides. The steel mesh 9 is 2cm below the surface of the soft soil foundation 11. The mesh size of the steel mesh 9 is 200mm × 200mm. The diameter of the steel bars in the steel mesh 9 is 8mm. A fiberglass geogrid 7 is laid between the middle layer 5 and the lower layer 4.

[0035] The construction steps for the aforementioned deformation-coordinated roadbed and pavement structure are as follows:

[0036] (1) Construct retaining walls 1 on both sides of the road on the soft soil foundation 11, and reserve welding points on the inner side of the retaining wall 1.

[0037] (2) A steel reinforcement support 10 is installed 30cm below the surface of the soft soil foundation 11, and the two ends of the steel reinforcement support 10 are welded to the retaining walls 1 on both sides.

[0038] (3) The soft soil between the surface of the soft soil foundation 11 and the steel reinforcement support 10 is replaced with 6% cement soil treatment, compacted and shaped to form cement soil treatment replacement layer 2.

[0039] (4) Apply rubber asphalt macadam seal coat at a rate of 2.2 kg / m³. 2 .

[0040] (5) Lay a layer of steel mesh 9, and weld the two ends of the steel mesh 9 to the retaining walls 1 on both sides as one unit.

[0041] (6) Lay cast-in-place asphalt concrete to form a base course 8 with a thickness of 4cm, and spray non-stick emulsified asphalt.

[0042] (7) Lay HRF-13 asphalt concrete to form an upper base layer 3 with a thickness of 6cm, and spray non-stick emulsified asphalt.

[0043] (8) Lay the lower layer 4 and the middle layer 5 of GAC-20. The middle layer 5 and the lower layer 4 adopt a double-layer continuous paving construction process. The thickness of the lower layer 4 is 8cm and the thickness of the middle layer 5 is 6cm. Fiberglass grid 7 is laid between the layers. Non-stick emulsified asphalt is sprayed on the surface of the middle layer 5.

[0044] (9) Lay TUT-7 surface layer 6 with a thickness of 2cm.

Claims

1. A deformation-coordinated roadbed and pavement structure, characterized in that, This includes soft soil foundations, retaining walls on both sides of roads located on soft soil foundations, and fully flexible asphalt pavement layers; A steel reinforcement frame is embedded inside the soft soil foundation, and the two ends of the steel reinforcement frame are rigidly connected to the retaining walls on both sides. The space between the steel reinforcement support and the soft soil foundation surface is a cement-treated soil replacement layer; The fully flexible asphalt pavement layer consists of, from bottom to top, a lower base layer, an upper base layer, a lower surface layer, an intermediate surface layer, and a surface layer. The lower base layer is equipped with a steel mesh, which is rigidly connected to the retaining walls on both sides. A layer of fiberglass grid is laid between the middle layer and the bottom layer.

2. The deformation-coordinated roadbed and pavement structure according to claim 1, characterized in that, The upper surface of the retaining wall is on the same horizontal plane as the upper surface of the lower base layer in the fully flexible asphalt pavement.

3. The deformation-coordinated roadbed and pavement structure according to claim 1, characterized in that, The steel reinforcement support is a 1m×1m-3m×3m steel mesh.

4. The deformation-coordinated roadbed and pavement structure according to claim 1, characterized in that, The reinforcing bars of the steel bar support are made of threaded steel with a diameter of 12mm.

5. The deformation-coordinated roadbed and pavement structure according to claim 1, characterized in that, The steel reinforcement support is buried 25-30cm below the surface of the soft soil foundation.

6. The deformation-coordinated roadbed and pavement structure according to claim 1, characterized in that, The steel mesh installed inside the lower base layer is 2-3 cm away from the surface of the soft soil foundation.

7. The deformation-coordinated roadbed and pavement structure according to claim 1, characterized in that, The mesh size of the steel mesh is 100mm×100mm-200mm×200mm.

8. The deformation-coordinated roadbed and pavement structure according to claim 1, characterized in that, The diameter of the steel bars in the steel mesh is 8mm.

9. The deformation-coordinated roadbed and pavement structure according to claim 1, characterized in that, The thickness of the lower base layer in the fully flexible asphalt pavement is 3-5cm; the thickness of the upper base layer is 6-8cm; the thickness of the lower layer is 6-10cm; the thickness of the middle layer is 4-8cm; and the thickness of the surface layer is 1.5-2.5cm.

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