A bridge abutment back roadbed structure suitable for steep sections of mountainous areas
By using a bridge abutment backfill subgrade structure that combines anti-skid mechanism with lightweight foamed soil in steep mountain sections, the problem of uneven settlement was solved, the bearing capacity and stability of the subgrade were improved, cracks and bumps were prevented, and the service life of the highway was extended.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- CCCC SECOND HIGHWAY CONSULTANTS CO LTD
- Filing Date
- 2025-07-25
- Publication Date
- 2026-07-24
Smart Images
Figure CN224548870U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of mountain road construction technology, and in particular to a bridge abutment backfill subgrade structure suitable for steep mountain road sections. Background Technology
[0002] Uneven settlement on the free side and the mountain-side of steep mountain roads, caused by differences in foundation conditions, fill thickness and stress environment, is a long-standing technical problem in the field of highway engineering. This uneven settlement often forms settlement cracks in the longitudinal direction of the road and induces vehicle bumps, road surface damage and retaining structure deformation, which seriously weakens road operation safety, driving comfort and service durability. Summary of the Invention
[0003] This application provides a bridge abutment backfill subgrade structure suitable for steep mountain road sections, which can improve the settlement characteristics of mountain road subgrade, enhance the overall stability and bearing capacity of subgrade soil, effectively reduce the self-compression of subgrade, and improve road operation safety, driving comfort and service durability.
[0004] This application provides a bridge abutment backfill subgrade structure suitable for steep mountain road sections, comprising:
[0005] Anti-slip mechanism;
[0006] The abutment back roadbed includes, from bottom to top, a first grade crushed stone layer, a foamed lightweight soil layer, a second grade crushed stone layer, and a shock-absorbing layer.
[0007] Furthermore, the abutment subgrade also includes geocells disposed within the first graded crushed stone layer, the foamed lightweight soil layer, and / or the second graded crushed stone layer, with one end of each geocell fixed to the anti-slip mechanism.
[0008] In some embodiments, the anti-skid mechanism includes a baffle and a baffle stop, the baffle being located between the baffle stop and the abutment roadbed.
[0009] In some embodiments, the baffle abutment includes a plurality of spaced-apart anti-slide piles.
[0010] In some embodiments, one end of the geocell is fixed to the anti-slip mechanism by a fastener.
[0011] In some embodiments, a fixing element is also provided at the other end of the geocell;
[0012] And / or, the top of the abutment roadbed is paved with road surface material;
[0013] And / or, a permeable geotextile isolation layer is provided between the first grade crushed stone layer and the foamed lightweight soil layer.
[0014] In some embodiments, the foamed lightweight soil layer is provided in multiple layers from bottom to top, and each foamed lightweight soil layer is provided with a geocell.
[0015] In some embodiments, the damping layer is a layer of elastic rubber gravel.
[0016] In some embodiments, the elastic rubber gravel layer comprises rubber particles and graded gravel, wherein the graded gravel fills the gaps between the rubber particles.
[0017] In some embodiments, a connection portion cured by an adhesive is provided between the rubber particles, between the graded gravel and the graded gravel, and / or between the rubber particles and the graded gravel.
[0018] In some embodiments, the rubber particles have a particle size of 5 to 10 mm, and the graded gravel has a particle size of 4.75 to 26.5 mm.
[0019] The beneficial effects of the technical solution provided in this application include:
[0020] This application provides a bridge abutment backfill subgrade structure suitable for steep mountain road sections. On one hand, this application fixes the abutment backfill subgrade with an anti-slip mechanism. The road subgrade formed by the anti-slip mechanism and lightweight foamed soil can significantly improve the bearing capacity of the roadbed in mountainous areas. Moreover, the use of lightweight foamed soil on the free side where the stress is most unfavorable reduces the self-weight of the roadbed, significantly reduces the additional stress on the foundation, and suppresses the later settlement after construction, resulting in a significant reduction in settlement. This prevents "longitudinal cracks" and driving bumps caused by uneven settlement, and improves the settlement control capability of the roadbed in steep mountain sections.
[0021] Secondly, honeycomb-shaped geocells are laid and filled with graded crushed stone or foamed lightweight soil. The geocells are fixed on the anti-slip mechanism. The overall bearing capacity and anti-lateral displacement performance are improved through lateral restraint and stress homogenization. With the stress diffusion of graded crushed stone or foamed lightweight soil, the concentrated load of the vehicle is transformed into a uniformly distributed load.
[0022] Thirdly, embedding a damping layer into the road structure effectively absorbs traffic impact loads and allows for a certain degree of differential displacement, thus avoiding stress concentration and crack propagation.
[0023] Through the above design, the synergistic effect of geocells with foamed lightweight soil, graded crushed stone, and damping layer significantly improves the settlement characteristics, structural stability, and bearing capacity of the roadbed, which can extend the service life of mountain highways and ensure driving safety and comfort on steep road sections. Attached Figure Description
[0024] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0025] Figure 1 A schematic diagram of the abutment backfill subgrade structure for steep mountain road sections provided in this application embodiment;
[0026] Figure 2 This is a schematic diagram of the planar arrangement of anti-slide piles and baffles provided in an embodiment of this application.
[0027] In the diagram: 1. Anti-skid mechanism; 10. Baffle; 11. Anti-skid pile; 2. Abutment backfill; 20. First grade crushed stone layer; 21. Foamed lightweight soil layer; 22. Second grade crushed stone layer; 23. Shock-absorbing layer; 24. Geocell; 25. Fastener; 3. Road surface material; 4. Mountain rock and soil layer. Detailed Implementation
[0028] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0029] See Figure 1 As shown in the figure, this application embodiment provides a bridge abutment backfill subgrade structure suitable for steep road sections in mountainous areas, which includes an anti-skid mechanism 1 and abutment backfill subgrade 2. The abutment backfill subgrade 2 includes a first graded crushed stone layer 20, a foamed lightweight soil layer 21, a second graded crushed stone layer 22 and a shock-absorbing layer 23 arranged sequentially from bottom to top. The abutment backfill subgrade 2 also includes geocells 24 disposed in the first graded crushed stone layer 20, the foamed lightweight soil layer 21 and / or the second graded crushed stone layer 22, and one end of the geocells 24 is fixed to the anti-skid mechanism 1.
[0030] In this application, the anti-skid mechanism 1 is inserted into the original rock and soil layer 4 of the mountain and is located on the free side of the steep section of the mountain road. The space formed between the anti-skid mechanism 1 and the mountain-side of the steep section of the mountain road provides conditions for the construction of the abutment roadbed 2.
[0031] The graded crushed stone layer uses a particle size of 4.75–37.5 mm, with continuous gradation, a crushing value ≤26%, and a mud content ≤5%. The layered compaction degree is ≥96%. The graded crushed stone layer can quickly drain seepage water, preventing water accumulation and softening of the subgrade, and can also transfer vertical loads through the particle skeleton. It should be noted that the parameters here are only illustrative examples of graded crushed stone layers and are not exhaustive; appropriate parameters can be adjusted according to actual needs.
[0032] The geocell has a tensile strength ≥25MPa, a weld peel force ≥200N / cm, a cell height of 100–200mm, and a honeycomb pore size of 150–300mm after unfolding. The honeycomb structure of the geocell restricts the lateral displacement of the filler material, converts concentrated loads into uniformly distributed loads, and reduces local settlement differences. It should be noted that the parameters here are only illustrative examples of geocells and are not exhaustive; appropriate parameters can be adjusted according to actual needs.
[0033] Foamed lightweight soil comprises cement (20%–30% by mass), foaming agent, water, and admixtures. Its self-weight is only 30%–50% of conventional fillers, reducing additional stress. Its self-leveling properties effectively fill geocell voids, preventing delamination. It should be noted that the parameters here are merely illustrative examples of foamed lightweight soil and are not exhaustive; adjustments can be made to suit specific needs. For instance, foamed lightweight soil can be purchased ready-made or manufactured in-house.
[0034] On the one hand, this application fixes the abutment roadbed with the anti-slip mechanism. The roadbed formed by the anti-slip mechanism and lightweight foamed soil can significantly improve the bearing capacity of the roadbed in mountainous areas. Moreover, the use of lightweight foamed soil on the free side where the stress is most unfavorable reduces the self-weight of the roadbed, significantly reduces the additional stress on the base, and suppresses the later settlement after construction, resulting in a significant reduction in settlement. This prevents "longitudinal cracks" and driving bumps caused by uneven settlement, and improves the settlement control capability of the roadbed in steep mountain sections.
[0035] Secondly, honeycomb-shaped geocells are laid and filled with graded crushed stone or foamed lightweight soil. The geocells are fixed on the anti-slip mechanism. The overall bearing capacity and anti-lateral displacement performance are improved through lateral restraint and stress homogenization. With the stress diffusion of graded crushed stone or foamed lightweight soil, the concentrated load of the vehicle is transformed into a uniformly distributed load.
[0036] Thirdly, embedding a damping layer into the road structure can effectively absorb the impact load from traffic and allow for a certain degree of differential displacement, such as ±5 mm, to avoid stress concentration and crack propagation.
[0037] Through the above design, the synergistic effect of geocells with foamed lightweight soil, graded crushed stone, and damping layer significantly improves the settlement characteristics, structural stability, and bearing capacity of the roadbed, which can extend the service life of mountain highways and ensure driving safety and comfort on steep road sections.
[0038] Further, see Figure 1 As shown in Figure 2, the anti-skid mechanism 1 includes a baffle 10 and a baffle stopper, wherein the baffle 10 is located between the baffle stopper and the abutment roadbed 2.
[0039] The baffle and abutment components can be made of plate-shaped materials, or such as... Figure 2 As shown, the baffle abutment includes a plurality of anti-skid piles 11 arranged at intervals. The anti-skid piles 11 are distributed along the length of the roadbed, but are not limited thereto.
[0040] The dimensions of the anti-slide pile 11 can be determined according to actual needs. For example, the minimum diameter of the anti-slide pile 11 is ≥0.8m (commonly 1.5~2.5m) to ensure bending stiffness, and the embedment depth in the stable stratum is 1 / 3 to 1 / 2 of the pile length. The anti-slide pile 11 can withstand the lateral pressure from the foamed lightweight soil layer and the upper subgrade material, transfer the load to the stable stratum, provide lateral restraint, and prevent horizontal displacement on the free side of the road.
[0041] The baffle 10 can be cast from reinforced concrete or other materials. This application takes reinforced concrete as an example, but is not limited thereto. The baffle 10 is used to withstand the lateral pressure generated by the graded crushed stone layer, foamed lightweight soil and the upper subgrade material, and to transfer the lateral pressure to the anti-slide pile.
[0042] Further, see Figure 1 As shown, one end of the geocell 24 is fixed to the anti-slip mechanism 1 by a fastener 25. The fastener 25 can be a rivet, but is not limited to this; other materials can be used as long as they achieve the fixing purpose.
[0043] Further, see Figure 1 As shown, a fixing member 25 is also provided at the other end of the geocell 24, which can fix the geocell 24 in the original mountain rock and soil layer 4.
[0044] Rivets can be made of either plastic or steel, but are not limited to either. For example, plastic rivets can be made of HDPE material with a tensile strength ≥20kN, a length of 300-500mm, and an anchoring depth ≥200mm. Steel rivets can be made of Q235 galvanized steel with a diameter of 10-12mm, and the matching washer has a pull-out resistance ≥5kN. It should be noted that the parameters here are only illustrative examples of rivets and are not exhaustive; the parameters can be adjusted according to actual needs.
[0045] Rivets are used to fix geocells and prevent them from shifting during construction and during road use after construction.
[0046] Further, see Figure 1 As shown, the foamed lightweight soil layer 21 is arranged in multiple layers from bottom to top, and each foamed lightweight soil layer 21 is provided with a geocell 24.
[0047] Furthermore, the damping layer 23 is an elastic rubber gravel layer.
[0048] It should be noted that the elastic rubber gravel layer mentioned here is only an example of a shock-absorbing layer, but it is not a limitation and can be selected according to actual needs.
[0049] The elastic rubber gravel layer comprises rubber particles and graded gravel, wherein the graded gravel fills the gaps between the rubber particles. Connecting portions cured with an adhesive are provided between the rubber particles, between the graded gravel particles, and / or between the rubber particles and the graded gravel. The rubber particles have a particle size of 5–10 mm, and the graded gravel has a particle size of 4.75–26.5 mm.
[0050] The elastic rubber gravel layer is composed of rubber particles, graded gravel, and binder, compacted together. It has a thickness of 30–50 cm and a resilience modulus ≥80 MPa. This layer absorbs vehicle impact energy. Depending on actual needs, the damping layer can be designed to accommodate differential settlement of ±5 mm, reducing stress concentration under vehicle loads. It should be noted that the parameters described here are merely illustrative examples of the elastic rubber gravel layer and are not exhaustive; adjustments can be made to meet specific requirements.
[0051] The adhesive can be a commonly used adhesive such as polyurethane.
[0052] Waste tires can be selected as the raw material for the rubber particles in the shock-absorbing layer, realizing the resource utilization of solid waste and meeting the requirements of low-carbon construction.
[0053] Road surface material 3 can also be laid on the surface of the damping layer 23, and conventional road surface materials can be used.
[0054] A permeable geotextile isolation layer can also be set between the first graded crushed stone layer 20 and the foamed lightweight soil layer 21. The permeable geotextile isolation layer and the graded crushed stone work together to drain water, which can quickly divert rainwater, prevent the base from softening and reduce the risk of soil erosion in the mountain.
[0055] This application also provides specific implementation steps for a bridge abutment backfill subgrade structure suitable for steep mountain road sections:
[0056] S1: Construct anti-slide piles in the roadbed construction area on the free side of the road, and construct retaining walls after the anti-slide piles have been cured.
[0057] S2: Excavate steps in the roadbed construction area, and level and compact the excavated steps to ensure that there are no hard protrusions such as gravel or boulders on the base surface.
[0058] S3: After the base is leveled, the first-grade crushed stone layer is laid. The first-grade crushed stone layer should be laid in layers, and the compaction degree should be ensured to meet the construction requirements. When the first-grade crushed stone layer reaches a certain thickness, the geocells are installed.
[0059] S4: During the installation of geocells, the geocell components should be fully opened to form a honeycomb structure. The overlap width of the geocells should not be less than 20cm, and they should be fixed to the base and baffle with rivets. After the geocells are installed, continue to lay the first grade of crushed stone layer to the set height.
[0060] S5: After the first grade of crushed stone is laid, the foamed lightweight soil layer is poured. Before pouring, the first grade of crushed stone is leveled and any sharp protrusions are removed. A permeable geotextile isolation layer is laid. The permeable geotextile isolation layer acts as a filter and prevents the foamed lightweight soil slurry from seeping into the pores of the crushed stone, thus avoiding blockage of the drainage channels.
[0061] S6: After the permeable geotextile isolation layer is laid, the foamed lightweight soil is poured. Before pouring, a protective wall should be set on the side of the foamed lightweight soil layer to ensure that it does not lose or deform during the pouring process.
[0062] S7: During the pouring process, the foamed lightweight soil of each excavation step should be pumped in three layers (lower, middle, and upper) using a hose, according to the actual pouring thickness.
[0063] S8: After the lower layer of lightweight foamed soil is poured for each excavation step, cover and protect it, and cure it. After the lower layer of lightweight foamed soil has reached a certain strength, lay the geocells. During the laying of the geocells, the geocell components should be fully opened to form a honeycomb structure, and fixed to the mountain rock and soil layers and baffles to prevent displacement during the pouring of the lightweight foamed soil.
[0064] S9: After the geocell is installed, continue to pour the foamed lightweight soil in the middle and upper layers of the excavated steps. After pouring, cover and protect it in time and carry out curing. The curing period shall not be less than 7 days.
[0065] S10: Repeat steps S7 to S9 until the foamed lightweight soil at the top excavation step is poured and cured. Then lay the second graded crushed stone layer and geocells. Before laying the second graded crushed stone layer, the hardened foamed lightweight soil should be milled to increase its roughness and improve the mechanical bonding between the foamed lightweight soil and the graded crushed stone.
[0066] S11: After the second grade crushed stone layer and geocells are laid, the elastic rubber gravel layer is laid. Rubber granules (mass fraction 30%–40%), graded gravel (mass fraction 55%–65%), and polyurethane adhesive (mass fraction 3%–5%) are dry-mixed using a forced mixer, then applied in layers and compacted.
[0067] S12: After the elastic rubber gravel layer is laid, the road surface material is laid.
[0068] In the description of this application, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.
[0069] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.
[0070] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.
Claims
1. A bridge abutment backfill subgrade structure suitable for steep mountain road sections, characterized in that, It includes: Anti-slip mechanism (1); The abutment back roadbed (2) includes a first grade crushed stone layer (20), a foamed lightweight soil layer (21), a second grade crushed stone layer (22), and a shock-absorbing layer (23) arranged sequentially from bottom to top. In addition, the abutment roadbed (2) also includes geocells (24) disposed in the first grade crushed stone layer (20), the foamed lightweight soil layer (21) and / or the second grade crushed stone layer (22), one end of the geocells (24) being fixed to the anti-slip mechanism (1).
2. The bridge abutment backfill subgrade structure suitable for steep mountain road sections as described in claim 1, characterized in that: The anti-skid mechanism (1) includes a baffle (10) and a baffle stop, wherein the baffle (10) is located between the baffle stop and the abutment roadbed (2).
3. The bridge abutment backfill subgrade structure suitable for steep mountain road sections as described in claim 2, characterized in that: The baffle abutment includes multiple anti-slide piles (11) arranged at intervals.
4. The bridge abutment backfill subgrade structure suitable for steep mountain road sections as described in claim 1, characterized in that: One end of the geocell (24) is fixed to the anti-slip mechanism (1) by a fastener (25).
5. The bridge abutment backfill subgrade structure suitable for steep mountain road sections as described in claim 1, characterized in that: The other end of the geocell (24) is also provided with a fastener (25); And / or, the top of the abutment roadbed (2) is covered with road surface material (3); And / or, a permeable geotextile isolation layer is provided between the first grade crushed stone layer (20) and the foamed lightweight soil layer (21).
6. The bridge abutment backfill subgrade structure suitable for steep mountain road sections as described in claim 1, characterized in that: The foamed lightweight soil layer (21) is arranged in multiple layers from bottom to top, and each foamed lightweight soil layer (21) is provided with a geocell (24).
7. The bridge abutment backfill subgrade structure as described in claim 1, suitable for steep mountain road sections, characterized in that: The shock-absorbing layer (23) is made of elastic rubber gravel.
8. The bridge abutment backfill subgrade structure as described in claim 7, suitable for steep mountain road sections, characterized in that: The elastic rubber gravel layer includes rubber particles and graded gravel, wherein the graded gravel fills the gaps between the rubber particles.
9. The bridge abutment backfill subgrade structure suitable for steep mountain road sections as described in claim 8, characterized in that: A connection portion cured by an adhesive is provided between the rubber particles, between the graded gravel and the graded gravel, and / or between the rubber particles and the graded gravel.
10. The bridge abutment backfill subgrade structure suitable for steep mountain road sections as described in claim 8, characterized in that: The rubber particles have a particle size of 5-10 mm, and the graded gravel has a particle size of 4.75-26.5 mm.