A subgrade structure of a highway crossing a goaf and a construction method thereof

Abstract

The application belongs to the technical field of road construction, and particularly relates to a roadbed structure of an expressway crossing a mined-out area and a construction method thereof. The roadbed structure comprises a first waterproof layer, a roadbed and a stable soil layer. The roadbed comprises a concrete bottom plate, a concrete side plate, a partition plate, a beam and a geocell. The partition plate is arranged in an area surrounded by the concrete bottom plate and the concrete side plate, and the first filler is arranged between the partition plates or between the partition plate and the concrete side plate. The beam is arranged above the partition plate and / or the concrete side plate, and the second filler is filled around and above the beam. The geocell is arranged above the second filler inside an area surrounded by the concrete side plate and the concrete bottom plate, and the third filler is filled in the geocell. The roadbed structure can effectively solve the local pressure concentration and uneven settlement caused by the underground cavity in the mined-out area, and has stronger adaptability in bearing capacity and stability.

Description

Technical Field

[0001] This invention belongs to the field of road construction technology, specifically relating to a roadbed structure and construction method for a highway traversing a mining subsidence area. Background Technology

[0002] Today, highways use various roadbed fillers, such as soil-rock mixtures and gravel-soil mixtures, which effectively improve the road's load-bearing capacity, ensure vehicle traffic flow, and extend road life to some extent. However, there are very few attempts to use solid waste materials as roadbed fillers, and roadbeds based on carboxylic lime are almost nonexistent. Specific construction methods urgently need improvement. Furthermore, as a solid waste material, large-scale accumulation of carboxylic lime not only occupies land but also harms the surrounding environment and affects public health.

[0003] A goaf is a hollow area left after underground coal mining, typically manifesting as voids or subsidence zones within the strata. In highway construction, the presence of goafs presents a series of potential safety risks and engineering challenges. Goafs can lead to unstable foundations, causing road surface settlement or collapse, severely impacting highway smoothness and operational safety. They can also result in insufficient soil bearing capacity, affecting the compaction and stability of the roadbed and increasing the risk of road surface cracking and deformation. Furthermore, goafs may trigger abnormal groundwater flow, further damaging the roadbed structure and even affecting the long-term performance of transportation facilities.

[0004] Therefore, there is a need to provide an improved technical solution that addresses the shortcomings of the existing technology. Summary of the Invention

[0005] The purpose of this invention is to provide a roadbed structure and construction method for a highway traversing a mining subsidence area, which helps to solve or improve at least one of the problems of pavement settlement, cracking and poor long-term performance that are prone to occur in highways in mining subsidence areas.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a roadbed structure for a highway traversing a mining subsidence area, comprising a first waterproof layer, a roadbed, and a stabilized soil layer arranged sequentially from bottom to top; the roadbed includes a concrete base slab, concrete side slabs, partitions, beams, and geocells; the concrete side slabs are disposed on the side of the concrete base slab; the partitions are disposed within the area enclosed by the concrete base slab and the concrete side slabs, and a first filler is disposed between the partitions or between the partitions and the concrete side slabs, the first filler being a mixture of carbide lime and expansive soil; the beams are disposed above the partitions and / or the concrete side slabs, and a second filler is disposed around and above the beams; the geocells are disposed above the second filler within the area enclosed by the corresponding concrete side slabs and the concrete base slab, and a third filler is disposed within the geocells.

[0007] Preferably, a second waterproof layer and / or a thermal insulation layer are provided between the concrete side plate and the first filler; the second waterproof layer is provided between the concrete side plate and the thermal insulation layer.

[0008] Preferably, the second filler is plain soil; the third filler is crushed stone.

[0009] Preferably, the thickness of the concrete base slab and / or concrete side slab is 30cm; the thickness of the partition is 20cm; and the partition is sealed to the concrete base slab.

[0010] The present invention also provides a construction method for the subgrade structure of a highway traversing a mining subsidence area as described above, which adopts the following technical solution: The construction method for the subgrade structure of a highway traversing a mining subsidence area as described above includes the following steps: (1) pre-construction preparation; (2) laying the first waterproof layer; (3) pouring the concrete base slab; (4) installing the concrete side slab; (5) installing the partition plate in the area enclosed by the concrete base slab and the concrete side slab; (6) filling the area enclosed by the concrete base slab and the concrete side slab with the first filler; (7) setting up a beam above the concrete side slab and / or the partition plate, and filling the beam with a second filler around and above the beam; (8) setting up a geocell above the second filler in the area enclosed by the corresponding concrete side slab and the concrete base slab, and filling the geocell with a third filler; (9) laying a stabilized soil layer above the geocell.

[0011] Preferably, the method further includes the step of installing a second waterproof layer and / or a thermal insulation layer on the inner side of the concrete side plate.

[0012] Preferably, after the concrete base slab is poured, it is vibrated, smoothed and cured; when installing the partition, the airtightness between the partition and the concrete base slab is ensured.

[0013] Preferably, when filling the first filler, the carbide lime and expansive soil are mixed evenly first, then shaped with a grader, and then compacted with a road roller over the entire width; after compaction, the first filler is cured for 14 days.

[0014] Preferably, after filling the second filler to a uniform and flat state, compaction is performed; when setting the geocell, the geocell needs to be straightened and smoothed, and tightly attached to the lower surface, with the joints anchored with U-shaped nails, and the third filler is then filled after anchoring is completed.

[0015] Beneficial effects:

[0016] In the roadbed structure of the highway traversing mining subsidence areas of this invention, the installation of concrete base slabs, concrete side slabs, partitions, and beams allows the entire roadbed to form a supporting foundation, greatly improving rigidity and stability and making it less prone to collapse. The use of partitions to separate the first fill material ensures that each portion of the calcium lime reacts fully with the expansive soil and also provides support for the highway, preventing uneven settlement. The installation of geocells helps to strengthen the roadbed structure and distribute the load. By laying geocells, the load from the upper part is transferred to the deeper subgrade, effectively reducing local pressure concentration caused by underground cavities or uneven settlement. The mixing of calcium lime and expansive soil as the first fill material forms a high-strength and stable roadbed material, maintaining the flatness and strength of the roadbed.

[0017] In the roadbed structure of the highway traversing mining subsidence areas of the present invention, the installation of an insulation layer and a second waterproof layer can regulate temperature and humidity changes. The insulation layer can mitigate temperature differences and prevent frost heave or thermal expansion and contraction caused by seasonal changes. In cold regions, it can effectively isolate external low temperatures, prevent roadbed frost heave, and reduce cracks and settlement caused by temperature changes. The second waterproof layer helps to solve the problem of groundwater infiltration in mining subsidence areas. It prevents groundwater from eroding the soil and roadbed materials, protects the completion of the chemical reaction between carbide lime and expansive soil, improves the water permeability resistance of the roadbed, and ensures the long-term stability of the soil. Attached Figure Description

[0018] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. Wherein:

[0019] Figure 1 A cross-sectional view of the roadbed structure of a highway traversing a mining subsidence area, provided in one embodiment of the present invention;

[0020] Figure 2 This is a top view of the roadbed structure of a highway traversing a mining subsidence area before the installation of geocells, according to an embodiment of the present invention.

[0021] Figure label:

[0022] 1-First waterproof layer; 2-Concrete base slab; 3-Concrete side slab; 4-Partition; 5-Second waterproof layer; 6-Insulation layer; 7-First filler; 8-Beam; 9-Second filler; 10-Third filler; 11-Geocell; 12-Stabilized soil layer; 13-Surface layer; 14-Void; 15-Foundation. Detailed Implementation

[0023] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention are within the scope of protection of the present invention.

[0024] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention 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. Therefore, they should not be construed as limiting this invention.

[0025] In the description of this invention, "several" means one or more, "more than" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0026] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" and "second" may explicitly or implicitly include one or more features.

[0027] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the term "connection" should be interpreted broadly. For example, it can be a fixed connection or a movable connection, a detachable connection or a non-detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection, or a connection that allows communication between the two components; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components, an indirect connection, or an interaction between two components.

[0028] The present invention will now be described in detail with reference to embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of the present invention can be combined with each other.

[0029] This invention addresses at least one of the problems currently existing in highways traversing mining subsidence areas, namely, road surface settlement, cracking, and poor long-term performance, by providing a roadbed structure for highways traversing mining subsidence areas.

[0030] like Figure 1-2As shown, the roadbed structure of the highway traversing a mining subsidence area according to an embodiment of the present invention includes a first waterproof layer 1, a roadbed, and a stabilized soil layer 12 arranged sequentially from bottom to top. The roadbed includes a concrete base slab 2, concrete side slabs 3, partitions 4, beams 8, and geocells 11. The concrete side slabs 3 are disposed on the side of the concrete base slab 2. The partitions 4 are disposed within the area enclosed by the concrete base slab 2 and the concrete side slabs 3. A first filler 7, which is a mixture of carbide lime and expansive soil, is disposed between the partitions 4 or between the partitions 4 and the concrete side slabs 3. The beams 8 are disposed above the partitions 4 and / or the concrete side slabs 3. A second filler is disposed around and above the beams 8. The geocells 11 are disposed above the second filler 9 within the area enclosed by the corresponding concrete side slabs 3 and the concrete base slab 2. A third filler 10 is disposed within the geocells 11. In this invention, the beams 8 serve to support and enhance the overall rigidity and bearing capacity of the roadbed.

[0031] In the roadbed structure of the highway traversing a mining subsidence area of ​​the present invention, the first waterproof layer 1 can prevent the infiltration of groundwater in the mining subsidence area, thereby helping to ensure the overall strength and stability of the road; the structure composed of concrete base slab 2, concrete side slabs 3, partition 4, first filler 7, and beam 8 can form the supporting foundation of the highway traversing the mining subsidence area, greatly improving the rigidity and stability of the pavement structure, and effectively solving the problem of mining subsidence areas ( Figure 1 The subgrade exhibits enhanced adaptability in terms of bearing capacity and stability by simulating the localized pressure concentration and uneven settlement caused by underground cavities (such as those in a mining subsidence area) through the creation of voids 14 in the foundation 15. Furthermore, the first filler 7, filling the space between the concrete base slab 2, concrete side slabs 3, and partition 4, is a mixture of calcium lime and expansive soil. After curing, it possesses sufficient strength (calcium lime reacts with water to produce calcium hydroxide, a reaction that releases heat, causing the calcium lime and expansive soil to form a dense structure), providing adequate bearing capacity.

[0032] Preferably, the beam 8 is arranged perpendicular to at least a portion of the concrete side slab 3 and / or partition 4 (e.g., Figure 2 (As shown); Beam 8 is connected to the concrete side plate 3 and / or partition 4 by means of steel bar binding.

[0033] More preferably, beam 8 can be a cast-in-place beam (where molds are erected and concrete is poured on-site according to the structural design) or a precast beam (reinforced concrete component). Even more preferably, beam 8 is a rectangular beam, which has good load-bearing capacity and stability.

[0034] The present invention employs a roadbed structure composed of a concrete base slab 2, concrete side slabs 3, partitions 4, first fill material 7, and beams 8. By setting beams 8 and partitions 4, the overall stability and bearing capacity of the roadbed are enhanced. Compared to a structure that replaces partitions 4 and beams 8 with a roof slab, this structure is more suitable for highways in mining subsidence areas. This is because using a roof slab would create a greater structural burden, and the soil layers in mining subsidence areas are often uneven and complex. Using a roof slab may increase the risk of settlement or cause structural deformation. In contrast, the roadbed structure composed of a concrete base slab 2, concrete side slabs 3, partitions 4, first fill material 7, and beams 8 can better transfer the load to the deeper subgrade, preventing roadbed collapse caused by underground cavities and uneven settlement in mining subsidence areas. Specifically, beam 8 can transfer loads, especially in uneven geological environments such as goaf areas. Beam 8 can help distribute the load of the upper layer evenly to the lower foundation, avoiding local pressure concentration caused by underground cavities and uneven settlement. The partition plate 4 not only helps to separate the mixing area of ​​the first filler 7 and prevent the mixing layer from being disturbed by the outside, but also effectively controls the layered structure of the reaction between carbide lime and expansive soil in the first filler 7. The partition plate 4 also plays a role in enhancing the overall rigidity.

[0035] In a preferred embodiment of the roadbed structure of the highway traversing a mining subsidence area according to the present invention, a second waterproof layer 5 and / or a thermal insulation layer 6 are provided between the concrete side plate 3 and the first filler 7; the second waterproof layer 5 is provided between the concrete side plate 3 and the thermal insulation layer 6. The second waterproof layer 5 helps prevent groundwater erosion of the roadbed material, protects the completion of the chemical reaction between the lime and expansive soil, improves the roadbed's water permeability resistance, and ensures long-term soil stability. The thermal insulation layer 6 helps avoid the adverse effects of drastic temperature changes throughout the day in the mining subsidence area, and helps ensure that the lime and expansive soil (first filler 7) can fully react during winter construction (the reaction of lime and expansive soil releases heat; the thermal insulation layer 6 reduces heat loss, thus helping to achieve a full reaction between lime and expansive soil in cold weather), ensuring roadbed strength. Furthermore, the thermal insulation layer 6 can mitigate temperature changes, preventing frost heave or thermal expansion and contraction caused by seasonal changes. In cold regions, it can effectively isolate external low temperatures, preventing roadbed frost heave and reducing cracks and settlement caused by temperature changes.

[0036] In a preferred embodiment of the roadbed structure of the highway traversing a mining subsidence area according to the present invention, the second filler 9 is plain soil; the third filler 10 is crushed stone. The first filler, a mixture of carbide lime and expansive soil, improves its strength, making the roadbed more load-bearing. The second filler, plain soil, serves as a transition layer, stabilizing the structure and providing good foundation support for the upper crushed stone or other materials, offering an elastic transition. The third filler, crushed stone, acts as a drainage layer. The selection of these fillers allows the materials of each layer of the roadbed structure to complement and synergistically enhance the overall stability of the roadbed structure.

[0037] Preferably, the crushed stone should be of uniform size with minimal difference in particle size between each other, and should be able to fill the gaps inside the geocell 11 without leaving any voids. More preferably, the particle size of the crushed stone is 10-40 mm.

[0038] In a preferred embodiment of the roadbed structure of the highway traversing a mining subsidence area according to the present invention, the amount of carboxylic acid in the first filler 7 is 8%, and the expansive soil is expansive soil from the mining subsidence area.

[0039] In a preferred embodiment of the roadbed structure of the highway traversing a mining subsidence area according to the present invention, the first waterproof layer 1 and / or the second waterproof layer 5 may be laid using materials with waterproof properties such as high-density polyethylene (HDPE) waterproof membrane or polyvinyl chloride (PVC) waterproof membrane; the thermal insulation layer 6 may be laid using materials with thermal insulation properties such as expanded perlite or XPS (extruded polystyrene foam board).

[0040] In a preferred embodiment of the roadbed structure of the highway traversing a mining subsidence area according to the present invention, the thickness of the concrete base slab 2 and / or the concrete side slab 3 is 30 cm; the thickness of the partition 4 is 20 cm; the partition 4 is sealed to the concrete base slab 3 (preferably, the sealed connection between the partition 4 and the concrete base slab 3 is achieved by chemical sealant or sealing strip). The concrete side slab 3 and the partition 4 need to have sufficient rigidity to support the first filler layer (a mixture of carbide lime and expansive soil) and other upper materials, preventing lateral displacement.

[0041] Preferably, the height of the concrete side plate 3 and / or partition 4 is 0.6m; selecting this height of concrete side plate 3 and / or partition 4 helps to ensure the stability of the structure without being too high and avoiding material waste.

[0042] Preferably, the height of the geocell 11 is 10-30cm to effectively enhance the bearing capacity and stability of the subgrade.

[0043] The present invention also proposes a construction method for the subgrade structure of a highway traversing a mining subsidence area as described above, comprising the following steps: (1) pre-construction preparation; (2) laying a first waterproof layer 1; (3) pouring a concrete base slab 2; (4) installing concrete side plates 3; (5) installing partitions 4 in the area enclosed by the concrete base slab 2 and the concrete side plates 3; (6) filling the area enclosed by the concrete base slab 2 and the concrete side plates 3 with a first filler 7; (7) setting a beam 8 above the concrete side plates 3 and / or partitions 4, and filling a second filler 9 around and above the beam 8; (8) setting a geocell 11 above the second filler 9 in the area enclosed by the corresponding concrete side plates 3 and the concrete base slab 2, and filling a third filler 10 in the geocell 11; (9) laying a stable soil layer 12 in sequence above the geocell 11.

[0044] Preferably, step (1) includes: after determining the location to be constructed, cleaning the area around the surface of the goaf to prevent debris from appearing at the laying location and thus affecting the stability of the entire roadbed, and ensuring that the construction site is clean and tidy; transporting the geocells 11 and crushed stone and other materials to the construction site to complete the pre-construction preparations.

[0045] Preferably, in step (2), when laying the first waterproof layer 1, the first waterproof layer 1 should ensure full coverage, and the joints should be heat-sealed to ensure that there is no water seepage path.

[0046] In a preferred embodiment of the construction method for the roadbed structure of a highway traversing a mining subsidence area according to the present invention, the method further includes the step of installing a second waterproof layer 5 and / or a thermal insulation layer 6 on the inner side of the concrete side plate 3.

[0047] In a preferred embodiment of the construction method for the roadbed structure of a highway traversing a mining subsidence area according to the present invention, after the concrete base slab 2 is poured, it is vibrated, smoothed, and cured (the concrete base slab 2 is poured on the basis of the first waterproof layer 1, and after the concrete is poured, it needs to be vibrated, smoothed, and cured to ensure that the concrete base slab 2 is solid and uniform; during the curing period of the concrete base slab 2, appropriate humidity and temperature should be maintained to avoid cracking of the concrete base slab 2; preferably, the thickness of the concrete base slab 2 is 30cm); when installing the partition 4, the sealing between the partition 4 and the concrete base slab 2 is ensured.

[0048] Preferably, chemical sealant or sealing strips are used to fill and cure the gap between the partition 4 and the concrete base 2 to form a sealing layer, thereby ensuring the seal between the partition 4 and the concrete base 2.

[0049] In a preferred embodiment of the construction method for the roadbed structure of a highway traversing a mining subsidence area according to the present invention, when filling the first filler 7, the carbide lime and expansive soil are mixed evenly, then shaped with a grader, and then compacted with a road roller over the entire width; the curing time for the first filler 7 is 14 days (the beam 8 is installed after the curing is completed).

[0050] In a preferred embodiment of the construction method for the subgrade structure of a highway traversing a mining subsidence area according to the present invention, after filling the area within the corresponding concrete side plate 3 (i.e., the area enclosed by the concrete side plate 3; preferably, the concrete side plate 3 is arranged along the circumference of the concrete base plate 2) with the second filler 9 until it is uniformly flat (preferably, the second filler 9 is filled to a position slightly higher than the top surface of the beam 8 to help ensure the uniformity and flatness of the second filler 9), it is compacted; when setting the geocell 11, the geocell 11 needs to be straightened and smoothed, and tightly attached to the lower surface. The joints are anchored with U-shaped nails. After the anchoring is completed, the third filler 10 is backfilled until it is flush with the height of the geocell 11. After being leveled manually, it is compacted with a road roller.

[0051] Preferably, the concrete side plate 3 is arranged around the circumference of the concrete base plate 2; the construction area of ​​the highway crossing the mining subsidence area of ​​the present invention is larger than the area enclosed by the concrete side plate 3; the second filler 9 (preferably, the second filler can be plain soil) is backfilled in the construction area outside the concrete side plate 3 until it is flush with the top surface of the geocell 11.

[0052] In a preferred embodiment of the construction method for the subgrade structure of a highway traversing a mining subsidence area according to the present invention, a layer of stabilized soil is laid on top of the geocell 11 and compacted after laying to ensure that it is uniform and dense; the road surface layer 13 is laid on the stabilized soil layer 12. During the construction process, temperature and humidity need to be controlled to ensure the quality of the surface layer 13. After the surface layer 13 is laid, a road roller is used to compact it to ensure that it has good strength and durability.

[0053] In a preferred embodiment of the construction method for the roadbed structure of a highway traversing a mining subsidence area according to the present invention, the following steps are included:

[0054] (1) Pre-construction preparation: After determining the location to be constructed, clean the area around the surface of the goaf to prevent debris from appearing at the laying location and affecting the stability of the entire roadbed, and ensure that the construction site is clean and tidy; transport the geocells 11 and crushed stone and other materials to the construction site to complete the pre-construction preparation.

[0055] (2) Laying the first waterproof layer 1: Lay the first waterproof layer 1 on the cleaned ground (high-density polyethylene waterproof membrane or polyvinyl chloride waterproof membrane can be used). The first waterproof layer 1 should ensure full coverage. The joints should be heat-welded or otherwise sealed to ensure that there is no water seepage path.

[0056] (3) Pouring concrete base slab 2: On the basis of the first waterproof layer 1, pour concrete base slab 2 with a thickness of 30cm. After the concrete is poured, it needs to be vibrated, smoothed and cured to ensure that the base slab is solid and uniform. During the curing period, appropriate humidity and temperature should be maintained to avoid cracking on the surface of concrete base slab 2.

[0057] (4) Install concrete side plate 3: Install concrete side plate 3 on the upper part of concrete base plate 2, with a thickness of 30cm (preferably, the height of concrete side plate 3 is 0.6m; fill the gap between concrete base plate 2 and concrete side plate 3 with grouting material to enhance the sealing and bearing capacity between the two; concrete side plate 3 is set along the circumference of concrete base plate 2; more preferably, concrete side plate 3 is set in the circumference of concrete base plate 2).

[0058] (5) Install partition 4 between concrete base slab 2 and concrete side slab 3: Install internal partition 4 between concrete side slab 3 and concrete base slab 2. The thickness of partition 4 is 20cm. When installing partition 4, ensure its airtightness with concrete base slab 2 to avoid the formation of water penetration channels (fill the gap between partition 4 and concrete base slab 2 with chemical sealant or sealant strip to form a sealing layer). First, set a second waterproof layer 5 (high-density polyethylene waterproof membrane or polyvinyl chloride waterproof membrane can be selected) on the inner side of partition 4, close to concrete side slab 3, to enhance the waterproof performance of the roadbed and prevent water from entering. In addition, set a heat insulation layer 6 on the inner side of the second waterproof layer 5 (that is, the second waterproof layer 5 is set between concrete side slab 3 and heat insulation layer 6). The heat insulation layer 6 and the second waterproof layer 5 should be set at the same height as concrete side slab 3 and internal partition 4. During the laying process, it is necessary to ensure that the material joints are tight and there are no leaks. The thickness of heat insulation layer 6 should meet the design requirements.

[0059] (6) Fill the space between the concrete base slab 2 and the concrete side slab 3 with the first filler 7: In the space within the partition 4, mix the carbide lime and expansive soil thoroughly according to the design ratio (e.g., the carbide lime content is 8%) to ensure a complete reaction; after mixing evenly, immediately shape the surface with a grader (the flatness of the roadbed is ensured by shaping with a grader; during the shaping process, ensure that the grader blades are parallel to the ground to avoid unnecessary undulations; adjust the roadbed surface reasonably by adjusting the depth of the grader blades), and compact both sides of the road surface 2-3 times more. After shaping, compact the entire width with a light roller (before compaction, check whether the first filler 7 is uniform to avoid looseness or unevenness). The following steps should be taken: Select a suitable road roller, compact in layers, with each layer typically between 100mm and 150mm thick, and each layer should be compacted at least 3-5 times; use a combination of static and vibratory compaction, as vibratory compaction can effectively improve the density of the roadbed, while static compaction helps to enhance overall stability; after compaction, maintain a curing period of 14 days (during curing, the temperature should be kept between 10℃ and 30℃, and the humidity should generally be kept between 80% and 95%; during the curing period, avoid direct sunlight to prevent rapid evaporation of moisture; if site conditions permit, use coverings (such as wet burlap sacks or plastic film) to protect the surface and prevent moisture evaporation).

[0060] (7) A beam 8 is set above the concrete side plate 3 and partition plate 4. The beam 8 is perpendicular to the concrete side plate 3 and partition plate 4 (the beam 8 is connected to the concrete side plate 3 and partition plate 4 by steel reinforcement binding). A second filler 9 is filled around and above the beam 8 (the second filler 9 can be plain soil; the second filler 9 is filled to a position higher than the top surface of the beam 8, so that the second filler 8 is uniform and flat, and compacted to ensure the stability of the second filler; preferably, the height of the beam is 30cm, and the thickness of the plain soil above the beam 8 can be 10cm). Before rolling, the uniformity of the second filler 9 should be checked to avoid looseness or unevenness. A suitable road roller is selected, and the layers are compacted in layers. The layer thickness is generally controlled within 100mm to 150mm, and each layer is rolled at least 3-5 times. A combination of static rolling and vibratory rolling is adopted. Vibratory rolling can effectively improve the density of the roadbed, while static rolling helps to enhance the overall stability.

[0061] (8) A geocell 11 is set above the second filler 9 in the area enclosed by the corresponding concrete side plate 3 and concrete bottom plate 2 (preferably, the height of the geocell 11 is 10-30cm), and a third filler 10 is filled in the geocell 11: a layer of geocell 11 is laid on the backfill soil (second filler 9, i.e. plain soil). The geocell 11 needs to be straight and smooth, close to the lower surface, and there should be no twisting or wrinkling. The joints are anchored with U-shaped nails. After anchoring, crushed stone (particle size of 10-40mm) is used for backfilling until it is level with the height of the geocell 11. After manual leveling, it is compacted with a road roller. In addition, in the construction area outside the concrete side plate 3, the second filler 9 (plain soil) is used for backfilling until it is level with the top surface of the geocell 11.

[0062] (9) Lay a stabilized soil layer 12 above the geocell 11: Lay a layer of stabilized soil (lime stabilized soil; the height of the stabilized soil layer 12 can be 50cm) on the geocell 11, and compact it after laying to ensure that it is uniform and dense, so as to complete the construction of the roadbed structure of the highway crossing the mining area in this embodiment.

[0063] Then, the road surface layer 13 is laid on the stabilized soil layer 12 (preferably, asphalt concrete can be used as the surface material; the height of the surface layer can be 20cm). During the construction process, temperature and humidity need to be controlled to ensure the quality of the surface layer 13. After the surface layer 13 is laid, it is compacted by a road roller to ensure that it has good strength and durability.

[0064] After the paving is completed, check the construction quality of all layers to ensure that the connection between each layer is firm, the surface is flat and meets the requirements. For parts that require curing, such as the concrete base slab 2 and surface layer 13, curing should be carried out in accordance with the specifications to ensure their strength and stability.

[0065] This invention employs a mixed filler of carboxylic acid and expansive soil between the concrete base slab 2, partition 4, and concrete side slabs 3. Compared to traditional fillers, this significantly improves the engineering properties of the soil and enhances the bearing capacity and stability of the subgrade. The integrated support structure formed by the beams, concrete base slab, concrete side slabs, and partition system can distribute loads, reduce local pressure concentration, and minimize the risk of uneven settlement. The application of geocells in the subgrade helps to disperse and transfer upper loads, preventing local settlement and pavement cracking. The design of the first waterproof layer, second waterproof layer, and insulation layer not only effectively prevents groundwater infiltration but also reduces the impact of temperature changes on the subgrade materials, thereby extending the service life of the subgrade.

[0066] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A subgrade structure of a highway crossing a gob area, characterized by, The roadbed comprises a concrete bottom plate, a concrete side plate, a partition plate, a beam and a geocell, the concrete side plate is arranged at the side of the concrete bottom plate, the partition plate is arranged in the area surrounded by the concrete bottom plate and the concrete side plate, the first filler is arranged between the partition plates or between the partition plate and the concrete side plate, the first filler is a mixture of calcium carbide lime and expanded soil, the beam is arranged above the partition plate and / or the concrete side plate, the second filler is arranged around and above the beam, and the geocell is arranged above the second filler in the area surrounded by the corresponding concrete side plate and the concrete bottom plate, and the third filler is arranged in the geocell. The second waterproof layer and / or the thermal insulation layer are arranged between the concrete side plate and the first filler.

2. The highway substructure structure traversing a gob area according to claim 1, wherein, The second waterproof layer is arranged between the concrete side plate and the thermal insulation layer. The second filler is plain soil.

3. The highway substructure structure traversing a mined-out area according to claim 1, wherein, The third filler is gravel. The thickness of the concrete bottom plate and / or the concrete side plate is 30 cm, and the thickness of the partition plate is 20 cm.

4. The highway substructure structure traversing a mined-out area according to claim 1, wherein, The partition plate is sealingly connected with the concrete bottom plate. The method comprises the following steps:

5. The construction method of a roadbed structure of a highway crossing a gob area according to any one of claims 1 to 4, wherein (1) preparation before construction; (2) laying the first waterproof layer; (3) pouring the concrete bottom plate; (4) installing the concrete side plate; (5) installing the partition plate in the area surrounded by the concrete bottom plate and the concrete side plate; (6) filling the first filler in the area surrounded by the concrete bottom plate and the concrete side plate; (7) arranging the beam above the concrete side plate and / or the partition plate, and filling the second filler around and above the beam; (8) arranging the geocell above the second filler in the area surrounded by the corresponding concrete side plate and the concrete bottom plate, and filling the third filler in the geocell; (9) laying the stable soil layer above the geocell. The method further comprises the step of installing the second waterproof layer and / or the thermal insulation layer on the inner side of the concrete side plate.

6. The construction method of a roadbed structure of a highway crossing a gob area according to claim 5, wherein After the pouring of the concrete bottom plate is completed, the concrete bottom plate is vibrated, leveled and maintained; 7. The method of constructing a roadbed structure of a highway crossing a gob area according to claim 5, wherein When the partition plate is installed, the sealing between the partition plate and the concrete bottom plate is ensured. When the first filler is filled, the calcium carbide lime and the expanded soil are mixed uniformly, then the land is shaped by a land shaper, and after shaping, the first filler is rolled by a roller within the full width; 8. The method of constructing a roadbed structure of a highway crossing a gob area according to claim 5, wherein After the rolling is completed, the first filler is maintained, and the maintenance time of the first filler is 14 days. After the second filler is filled to be uniform and flat, the second filler is compacted; 9. The method of constructing a roadbed structure of a highway crossing a gob area according to claim 5, wherein, When the geocell is arranged, the geocell is straightened and smoothed, tightly adheres to the lower surface, and is anchored by a U-shaped nail at the joint, and after the anchoring is completed, the third filler is filled. ​

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