Bubble light soil roadbed structure

Abstract

The invention relates to the technical field of roadbed structures, and particularly discloses a bubble light soil roadbed structure which comprises an underlayer, a pavement structure layer, a bubble mixed light soil layer and a prefabricated reinforced concrete slab interlayer. The underlayer and the pavement structure layer are arranged at an interval, and the bubble mixed light soil layer is arranged between the underlayer and the pavement structure layer; the prefabricated reinforced concrete slab interlayer is arranged in the bubble mixed light soil layer, and the prefabricated reinforced concrete slab interlayer and the bottom layer as well as the prefabricated reinforced concrete slab interlayer and the pavement structure layer are separately arranged at intervals; wherein the prefabricated reinforced concrete slab interlayer comprises a plurality of concrete slab single bodies and a reinforcing mesh, and the reinforcing mesh is at least partially connected to the plurality of concrete slab single bodies in a penetrating mode. By arranging the prefabricated reinforced concrete slab interlayer, the compression resistance, shear resistance and bending resistance of the whole bubble light soil roadbed structure are remarkably improved, and the bubble light soil roadbed structure can be applied to scenes with higher requirements for the bearing capacity.

Description

Technical Field

[0001] This application relates to the field of roadbed structure technology, and in particular to a bubble-filled lightweight soil roadbed structure. Background Technology

[0002] Due to its lightweight and good fluidity, aerated lightweight soil is often used for roadbed widening, bridge abutment backfilling, and soft soil embankment filling. It can effectively reduce the load on the roadbed, control settlement, and solve problems such as bridge approach slab settlement. It can also be used in underground engineering such as pipeline backfilling, underground cavity filling, and tunnel load reduction filling (such as culverts and arch bridge tops), which can reduce the load of the overburden soil on the structure and improve safety.

[0003] However, in the existing construction process of foamed lightweight soil filling, unstable control of wet density during construction leads to inconsistent construction quality of different filling layers, resulting in weak interlayers or lenses with low strength. This causes poor interlayer bonding and strength dispersion, leading to localized settlement that affects driving safety and comfort. Furthermore, large-volume foamed lightweight soil is more prone to settlement and cracking, posing a significant threat to the stability of the lightweight soil filling body, especially for high-fill structures, which are highly susceptible to post-construction cracking and instability or upward reflection of cracks.

[0004] Although the density of aerated lightweight soil is adjustable, its bearing capacity is limited. When used directly in soft soil sections, the bearing capacity requirements of the foundation must be assessed. Otherwise, uneven settlement may occur. In high embankments or splicing scenarios between new and old subgrades, stress concentration effects are obvious, which can easily lead to the initial failure of the lightweight soil, resulting in local subsidence and affecting driving safety and comfort. Summary of the Invention

[0005] The technical problem to be solved by this application is: how to solve the problem of subsidence and cracking caused by poor stability of bubble-mixed lightweight soil filling in the existing technology, which affects driving safety and driving comfort.

[0006] To address the aforementioned technical problems, this application proposes a bubble-bubble lightweight soil subgrade structure, having a first orientation, comprising a subbase layer, a pavement structure layer, a bubble-bubble mixed lightweight soil layer, and a precast reinforced concrete slab interlayer. Along the first direction, the subbase layer and the pavement structure layer are spaced apart, and the bubble-mixed lightweight soil layer is disposed between the subbase layer and the pavement structure layer; the precast reinforced concrete slab interlayer is disposed within the bubble-mixed lightweight soil layer, and along the first direction, the precast reinforced concrete slab interlayer is spaced apart from the subbase layer and the pavement structure layer respectively. The precast reinforced concrete slab interlayer includes individual concrete slabs and a steel mesh. The steel mesh is at least partially connected to the individual concrete slabs. There are multiple individual concrete slabs spaced apart, and all of the multiple individual concrete slabs are connected by the steel mesh.

[0007] In some embodiments, the bubble-bubble lightweight soil subgrade structure also has a second direction and a third direction; The precast reinforced concrete slab interlayer is provided with a first post-pouring strip and a second post-pouring strip. At least some of the concrete slab units are spaced apart along the second direction, and the first post-cast strip is formed between two adjacent concrete slab units; At least some of the concrete slab units are spaced apart along the third direction, and a second post-cast strip is formed between two adjacent concrete slab units; The reinforcing mesh is located at least partially in the first post-cast strip and the second post-cast strip; Wherein, the first direction, the second direction, and the third direction are all perpendicular to each other.

[0008] In some embodiments, there are multiple precast reinforced concrete slab interlayers, and the multiple precast reinforced concrete slab interlayers are spaced apart along the first direction; Along the first direction, the first post-pouring strips on two adjacent precast reinforced concrete slab interlayers are staggered, and the second post-pouring strips on two adjacent precast reinforced concrete slab interlayers are staggered.

[0009] In some embodiments, the reinforcing mesh includes connected first and second reinforcing bars; The first reinforcing bar extends along the second direction, and the first reinforcing bar at least partially passes through the first post-cast strip; The second reinforcing bar extends along the third direction and at least partially passes through the second post-cast strip.

[0010] In some embodiments, the precast reinforced concrete slab interlayer further includes a third reinforcing bar and a fourth reinforcing bar; Along the second direction, the third reinforcing bar is spaced apart from the second reinforcing bar, the third reinforcing bar is located within the first post-cast strip and extends along the third direction, and the third reinforcing bar is connected to the first reinforcing bar; Along the third direction, the fourth reinforcing bar is spaced apart from the first reinforcing bar, the fourth reinforcing bar is located within the second post-cast strip and extends along the second direction, and the fourth reinforcing bar is connected to the second reinforcing bar.

[0011] In some embodiments, each of the concrete slab units is provided with a perforated groove that penetrates the concrete slab unit along the first direction; Along the second direction, at least a portion of the first reinforcing bar passes through the hollow groove; Along the third direction, at least a portion of the second reinforcing bar passes through the hollow groove.

[0012] In some embodiments, the hollowed-out slots are multiple and spaced apart.

[0013] In some embodiments, the total area S1 of the plurality of hollowed-out grooves and the total area S of each concrete slab unit satisfy: S≥3×S1.

[0014] In some embodiments, the thickness of the precast reinforced concrete slab interlayer along the first direction is L, satisfying: 5cm≤L≤20cm.

[0015] In some embodiments, along the first direction, the spacing between two adjacent precast reinforced concrete slab interlayers is H, satisfying: 50cm≤H≤100cm.

[0016] Compared with existing technologies, the beneficial effects of the bubble-filled lightweight soil subgrade structure proposed in this application are as follows: First, this application incorporates precast reinforced concrete slab interlayers within the aerated lightweight soil layer. These interlayers, composed of multiple individual concrete slabs and a steel mesh, possess high strength and rigidity. Compared to the low-strength aerated lightweight soil, they act as a continuous rigid reinforcement, dividing and "clamping" the aerated lightweight soil layer. This significantly enhances the shear and tensile strength of the aerated lightweight soil subgrade structure, substantially improving its structural integrity and ensuring effective and uniform load transfer in the vertical direction, thereby improving the overall stability of the subgrade structure. Secondly, the precast reinforced concrete slab interlayer acts as a rigid horizontal barrier, which can prevent shrinkage cracks or shear cracks that may be generated inside the aerated lightweight soil from developing upwards and prevent them from reflecting to the pavement structure layer, thus avoiding large-scale cracking instability or subsidence and ensuring driving comfort. At the same time, the combination of the precast reinforced concrete slab interlayer and the aerated lightweight soil layer can improve the deformation coordination of the entire fill, enabling it to better adapt to differential settlement. In summary, this application significantly improves the shear and tensile bearing capacity of the entire aerated lightweight soil subgrade structure by setting a precast reinforced concrete slab interlayer, while also improving the overall stiffness and deformation coordination of the aerated lightweight soil. This enables the aerated lightweight soil subgrade structure to be applied to scenarios with higher bearing capacity requirements, providing a greater safety reserve under the same geological conditions. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of a bubble-filled lightweight soil subgrade structure as described in this application.

[0018] Figure 2 This application Figure 1 A sectional view of section AA in the middle.

[0019] Figure 3 This application Figure 1 Sectional view of section BB.

[0020] Figure 4 This is an assembly diagram of the various concrete slab units described in this application.

[0021] Figure 5 This is a cross-sectional view of a single concrete slab unit described in this application along section CC.

[0022] Figure 6 This is a cross-sectional view of a single concrete slab unit described in this application along section DD.

[0023] Figure 7 This is a cross-sectional view of two adjacent concrete slabs along the CC section of this application.

[0024] Figure label: 1. Laying the bottom layer; 2. Road surface structural layer; 3. Bubble-mixed lightweight soil layer; 4. Precast reinforced concrete slab mezzanine; 41. Single concrete slab; 411. Hollowed-out groove; 42. Reinforcing mesh; 421. First reinforcing bar; 422. Second reinforcing bar; 43. Third reinforcing bar; 44. Fourth reinforcing bar; 401. First post-cast strip; 402. Second post-cast strip; 5. Concrete panel; X, first direction; Y, second direction; Z, third direction. Detailed Implementation

[0025] The specific embodiments of this application will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this application, but are not intended to limit the scope of this application.

[0026] In the description of this application, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" used to indicate orientation or positional relationships are based on the orientation or positional relationships shown in the accompanying drawings and are used only for the convenience of describing this application and simplifying the description, and are not intended to 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.

[0027] 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" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0028] Furthermore, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0029] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0030] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0031] like Figure 1 and Figure 2 As shown, this application proposes a bubble-bubble lightweight soil subgrade structure, which has a first direction X, a second direction Y, and a third direction Z; wherein the first direction X, the second direction Y, and the third direction Z are all mutually perpendicular. For ease of explanation, the thickness direction of the bubble-bubble lightweight soil subgrade structure is defined as the first direction X, the width direction of the bubble-bubble lightweight soil subgrade structure is defined as the second direction Y, and the length direction of the bubble-bubble lightweight soil subgrade structure is defined as the third direction Z.

[0032] In some implementation methods, please refer to Figure 1 and Figure 2 The aerated lightweight soil subgrade structure includes a base layer 1, a pavement structure layer 2, an aerated lightweight soil layer 3, and a precast reinforced concrete slab interlayer 4. Along the first direction X, the base layer 1 and the pavement structure layer 2 are spaced apart, and the aerated lightweight soil layer 3 is located between the base layer 1 and the pavement structure layer 2. The precast reinforced concrete slab interlayer 4 is located within the aerated lightweight soil layer 3, and along the first direction X, it is spaced apart from both the base layer 1 and the pavement structure layer 2. The combination of the precast reinforced concrete slab interlayer 4 and the aerated lightweight soil layer 3 improves the deformation coordination of the entire fill, provides a reliable force transmission path and overall stiffness, enhances the shear and tensile bearing capacity of the entire aerated lightweight soil subgrade structure, ensures effective and uniform load transfer in the vertical direction, and enables it to better adapt to differential settlement.

[0033] Furthermore, the precast reinforced concrete slab interlayer 4 of this application acts as a rigid horizontal barrier, preventing shrinkage or shear cracks that may arise within the aerated lightweight soil from propagating upwards and reflecting onto the pavement structure layer 2, thereby ensuring the integrity of the pavement and driving comfort. Even if stress concentration occurs due to abrupt changes in stiffness at the junction of new and old subgrades or transition sections of structures, the built-in precast reinforced concrete slab interlayer 4 can improve the stiffness and strength of the lightweight soil fill itself, enabling it to better bear and distribute stress and reducing the risk of plastic failure within the lightweight soil. At the same time, the combination of the precast reinforced concrete slab interlayer 4 and the aerated lightweight soil layer 3 can improve the deformation coordination of the entire fill, enabling it to better adapt to differential settlement. By setting the precast reinforced concrete slab interlayer 4, this application significantly improves the compressive, shear, and flexural bearing capacity of the entire aerated lightweight soil subgrade structure, allowing this aerated lightweight soil subgrade structure to be applied to scenarios with higher bearing capacity requirements, and providing a greater safety reserve under the same geological conditions, reducing the stringent requirements on foundation bearing capacity when relying solely on lightweight soil.

[0034] In a specific embodiment, the precast reinforced concrete slab sandwich layer 4 includes a concrete slab unit 41 and a steel mesh 42. The steel mesh 42 is at least partially connected to the concrete slab unit 41, so that the precast reinforced concrete slab sandwich layer 4 itself has high strength and high rigidity, and can serve as a continuous rigid reinforcement, thereby improving the bearing capacity of the entire aerated lightweight soil subgrade structure.

[0035] In some embodiments, multiple concrete slab units 41 are spaced apart and connected by a steel mesh 42. This allows the lightweight soil slurry to flow smoothly through the gaps in the precast reinforced concrete slab interlayer 4, tightly wrapping the upper, lower, and side surfaces of each concrete slab unit 41. This achieves mechanical interlocking and tight bonding between the lightweight soil and the concrete slab unit 41 in three-dimensional space. This avoids the problems of voids at the bottom and poor bonding that may occur when using large-area solid slabs, truly forming a composite reinforced structure of "reinforced concrete skeleton + lightweight soil filler," where both share the load and work together. Furthermore, during the layered pouring of the aerated lightweight soil layer 3, the spacing of the multiple concrete slab units 41 ensures tight bonding between the upper and lower layers of the aerated lightweight soil layer 3, improving the interface connection strength.

[0036] Furthermore, the lightweight soil areas between the concrete slab units 41 allow for small, controllable compressive deformation, which can absorb and buffer some of the tendency for uneven settlement, while the connecting steel mesh 42 ensures that this deformation does not get out of control. This achieves an ideal state of local flexibility and overall rigidity, which improves the load-bearing capacity while maintaining the structure's toughness.

[0037] In some embodiments, multiple concrete slab units 41 are arranged in a matrix on a horizontal plane; specifically, such as Figure 3 As shown, the precast reinforced concrete slab interlayer 4 is provided with a first post-pouring strip 401 and a second post-pouring strip 402; wherein, at least a portion of the concrete slab units 41 are spaced apart along the second direction Y, and a first post-pouring strip 401 is formed between two adjacent concrete slab units 41; at least a portion of the concrete slab units 41 are spaced apart along the third direction Z, and a second post-pouring strip 402 is formed between two adjacent concrete slab units 41; and the reinforcing mesh 42 is at least partially located in the first post-pouring strip 401 and the second post-pouring strip 402; the function of the first post-pouring strip 401 and the second post-pouring strip 402 is to allow air bubbles to mix with lightweight soil to pass through. When the lightweight soil slurry is poured, it can flow into and fill the first post-pouring strip 401 and the second post-pouring strip 402 without obstruction, so that the lightweight soil slurry can wrap each concrete slab unit 41 in all directions, thereby forming a strong mechanical interlocking and bonding, so that the rigid concrete slab unit 41 and the flexible lightweight soil are combined into a true integral composite structure to jointly bear the load, avoiding the bottom of the slab from being void or the bonding surface from becoming a weak surface.

[0038] It should be noted that post-pouring strips also enable highly fluid lightweight soil to flow smoothly and self-level, making it easier to achieve the designed filling thickness and uniformity, and reducing density stratification caused by poor pouring.

[0039] In addition, the first post-pouring strip 401 and the second post-pouring strip 402 can also serve as natural ventilation channels to ensure that the air inside the lightweight soil can be smoothly discharged during the pouring, which greatly reduces the risk of voids or loose areas forming under the concrete slab unit 41 due to air pockets, and ensures that the overall filling is dense and uniform.

[0040] In some embodiments, there are multiple precast reinforced concrete slab interlayers 4, and the multiple precast reinforced concrete slab interlayers 4 are spaced apart along the first direction X; the multiple precast reinforced concrete slab interlayers 4 can divide the thick aerated lightweight soil fill into multiple thinner "interlayer-lightweight soil" composite layers, and each precast reinforced concrete slab interlayer 4 forms a strong horizontal constraint on the lightweight soil in its upper and lower range, which greatly suppresses the lateral expansion and vertical uneven compression of the lightweight soil.

[0041] It should be noted that the precast reinforced concrete slab interlayer 4 is multiple and spaced apart, which can transform a large volume of relatively discrete foamed lightweight soil layer 3 into a composite layered structure supported and reinforced by multiple high-rigidity slabs. The overall stability and deformation resistance are greatly improved, fundamentally solving the problem of settlement and cracking of large volume foamed lightweight soil.

[0042] Furthermore, the multi-layered precast reinforced concrete slab sandwich layer 4 constitutes a multi-level, continuous rigid force transmission system, which can gradually diffuse and transfer the load from the road surface through the multi-layered precast reinforced concrete slab sandwich layer 4, resulting in a more uniform and gradual stress distribution. This effectively avoids the problem of excessive stress concentration at a certain depth at high embankments or at the junction of new and old roadbeds, which would lead to the premature failure of the lightweight soil, and significantly improves the overall bearing capacity of the roadbed and its ability to coordinate with uneven settlement.

[0043] In some implementations, if the post-cast strips of two adjacent precast reinforced concrete slab mezzanine layers 4 are aligned vertically in the first direction X, a continuous vertical channel composed of relatively "soft" aerated lightweight soil will be formed from top to bottom. Under load, stress tends to concentrate and be transmitted downwards along this "weak channel," forming a local "stress column," thus losing the stress diffusion effect that the multi-layer slab mezzanine design should achieve, and may even become a potential failure path. To address this, along the first direction X, the first post-cast strips 401 on two adjacent precast reinforced concrete slab mezzanine layers 4 are staggered, and the second post-cast strips 402 on two adjacent precast reinforced concrete slab mezzanine layers 4 are also staggered; that is, the staggered design ensures that the "weak areas" of the upper and lower layers are not on the same vertical line; thus, the load from the upper layer must first be received and diffused through the concrete slab unit 41 of the upper precast reinforced concrete slab mezzanine layer 4 before it can be transmitted to the concrete slab unit 41 of the lower precast reinforced concrete slab mezzanine layer 4. This forces the load transfer path to be zigzag or mesh-like, causing the misaligned concrete slab units 41 and the post-cast strips to form an interwoven grid skeleton in space. When local lightweight soil shrinks or the foundation settles slightly, this interwoven structure can better mobilize the restraining effect of the surrounding materials, producing a certain spatial "arch effect" and dispersing local deformation over a larger area.

[0044] In addition, any cracks that intend to grow upwards or downwards will have their propagation path forcibly deflected or terminated when they encounter the upper or lower concrete slab unit 41, making it almost impossible for them to form continuous cracks that penetrate several layers and affect the overall structure. This provides multiple and redundant defenses for the bubble lightweight soil subgrade structure.

[0045] It should be noted that if the post-cast strips are aligned vertically, when pouring the upper layer of lightweight soil, the grout may be poured directly through the upper post-cast strip, impacting the uncured lightweight soil below, potentially causing the lower layer of cast material to be broken up, segregated, or disturbed. Therefore, the staggered design of the first post-cast strip 401 and the second post-cast strip 402 of the upper and lower precast reinforced concrete slab interlayer 4 ensures that the grout poured in the upper layer must first flow through and cover the upper concrete slab unit 41 before flowing laterally into the post-cast strip area of ​​the lower layer. This guarantees that each layer of lightweight soil can be poured and solidified independently and in an orderly manner.

[0046] In some implementations, such as Figure 4 and Figure 5As shown, the reinforcing mesh 42 includes a first reinforcing bar 421 and a second reinforcing bar 422 connected together. The first reinforcing bar 421 extends along the second direction Y and penetrates the concrete slab unit 41 and connects two adjacent concrete slab units 41. The second reinforcing bar 422 extends along the third direction Z and penetrates the concrete slab unit 41 and connects two adjacent concrete slab units 41. Thus, the first reinforcing bar 421 and the second reinforcing bar 422 intersect each other and are firmly connected (by welding or binding), forming a spatial grid skeleton with high structural stability that covers the entire mezzanine plane. The reinforcing mesh 42 rigidly connects all concrete slab units 41 into a whole load-bearing unit. When any concrete slab unit 41 is under stress, the force can be quickly transferred to the surrounding concrete slab units 41 and reinforcing bars through the intersecting reinforcing bar nodes, realizing the redistribution and sharing of loads. This completely eliminates the risk of the concrete slab unit 41 bearing the load independently, ensuring that the precast reinforced concrete slab mezzanine 4 can function as a continuous and uniform reinforcement layer, fundamentally solving the problems of poor interlayer bonding and strength dispersion caused by component dispersion.

[0047] In some embodiments, the first reinforcing bar 421 is at least partially connected to the first post-cast strip 401; the second reinforcing bar 422 is at least partially connected to the second post-cast strip 402. Thus, the intersecting first and second reinforcing bars 421 and 422 provide strong binding forces in two mutually perpendicular directions. This bidirectional constraint effectively limits the relative displacement and warping of the concrete slab unit 41 in any direction within the horizontal plane, greatly enhancing the overall stiffness within the interlayer plane. When the lightweight soil within the post-cast strip shrinks or compresses, it attempts to pull adjacent slab units closer together or separate. The crisscrossing reinforcing mesh, through its tensile strength, strongly resists this tendency, thereby significantly suppressing the risk of cracking in the post-cast strip area and preventing localized settlement and upward reflection of cracks.

[0048] In some embodiments, to ensure the structural strength of the precast reinforced concrete slab interlayer 4 at the post-cast strip location; therefore, such as Figure 4 and Figure 7As shown, the precast reinforced concrete slab interlayer 4 also includes a third reinforcing bar 43 and a fourth reinforcing bar 44. Specifically, along the second direction Y, the third reinforcing bar 43 is spaced apart from the second reinforcing bar 422. The third reinforcing bar 43 is located within the first post-cast strip 401 and extends along the third direction Z, and is connected to the first reinforcing bar 421. Along the third direction Z, the fourth reinforcing bar 44 is spaced apart from the first reinforcing bar 421. The fourth reinforcing bar 44 is located within the second post-cast strip 402 and extends along the second direction Y, and is connected to the second reinforcing bar 422. Thus, the connection between the third reinforcing bar 43 and the first reinforcing bar 421 forms a mesh structure within the first post-cast strip 401, and the connection between the fourth reinforcing bar 44 and the second reinforcing bar 422 forms a mesh structure within the second post-cast strip 402. These reinforcing bars act like strong "stitching threads," rigidly connecting the spaced-apart concrete slab units 41 into a single load-bearing unit. They provide strong tensile strength, ensuring that adjacent concrete slab units 41 can deform together when subjected to bending and tension, effectively transferring bending moment and tensile force, fundamentally eliminating the separation of concrete slab units 41 at the joints, and ensuring the continuity of the entire precast reinforced concrete slab interlayer 4 in the plane.

[0049] Furthermore, due to the low shear strength of pure aerated lightweight soil, significant shear stress will be generated at the post-pouring strip location when the subgrade is subjected to vehicle loads or uneven settlement occurs. This can easily lead to shear failure of the lightweight soil, forming a sliding surface. The third and fourth reinforcing bars 43 and 44, together with the reinforcing mesh 42, form a "spatial truss" or "reinforced mesh" in the post-pouring strip area. The reinforcing bars mainly bear tensile forces, while the lightweight soil, tightly interlocked with the reinforcing bars, bears compressive forces. Working together, they significantly improve the overall shear resistance of the lightweight soil composite zone in the post-pouring strip. The shear force is converted into tensile stress in the reinforcing bars, thus effectively resisting it. This prevents shear failure from occurring first in the post-pouring strip, ensuring that the load can be safely transferred to the adjacent concrete slab unit 41 through the post-pouring strip.

[0050] In some implementations, such as Figure 3 , Figure 4 as well as Figure 6As shown, each concrete slab unit 41 is provided with a hollow groove 411, which penetrates the concrete slab unit 41 along the first direction X. The hollow groove 411 provides a channel for the lightweight soil to penetrate vertically through the thickness direction (first direction X) of the concrete slab unit 41. After pouring, the lightweight soil not only wraps the upper and lower surfaces and sides of the concrete slab unit 41, but also penetrates the interior of the concrete slab unit 41, forming numerous mechanical interlocking "concrete tenons-lightweight soil tenons". This three-dimensional interlocking structure upgrades the bonding force between the concrete slab unit 41 and the lightweight soil from relying on interface bonding (two-dimensional) to relying on the combined effect of mechanical interlocking and bonding (three-dimensional). Moreover, the concrete slab unit 41 is "anchored" in the lightweight soil, completely eliminating the possibility of horizontal or vertical relative displacement (delamination, slippage) between the two, making the composite structure formed by the bubble-mixed lightweight soil layer 3 and the precast reinforced concrete slab interlayer 4 a truly integrated whole, solving the hidden danger of poor interlayer bonding.

[0051] In some implementations, such as Figure 3 , Figure 4 as well as Figure 6 As shown, along the second direction Y, at least a portion of the first reinforcing bar 421 passes through the hollow groove 411; along the third direction Z, at least a portion of the second reinforcing bar 422 passes through the hollow groove 411. This allows the reinforcing mesh 42 to also pass through the hollow groove 411, establishing continuity in the thickness direction (first direction X) of the concrete slab unit 41. This transforms the reinforcing mesh from a "two-dimensional planar mesh" attached to a single-layer concrete slab unit 41 into a "three-dimensional spatial truss" that penetrates the lightweight soil and connects the upper and lower surfaces. This allows for more effective transmission and coordination of complex stresses within and outside the slab plane, transforming the entire "slab-lightweight soil-slab" composite layer into a highly unified whole in terms of mechanical behavior, greatly enhancing the stability and integrity of the structure in three-dimensional space.

[0052] In addition, the steel mesh 42 passes through the hollow groove 411, which is equivalent to adding a "steel core" to the "interlocking structure". After the lightweight soil solidifies, the steel mesh 42, the concrete slab 41 and the lightweight soil can be tightly interlocked together to form a composite with higher strength and more reliable performance; and the steel bars prevent shear slippage that may occur between the concrete slab 41 and the lightweight soil under extreme loads.

[0053] In some embodiments, to further improve the bond strength between the concrete slab unit 41 and the lightweight soil, multiple and spaced perforated grooves 411 are provided. These spaced perforated grooves 411 create dense, distributed lightweight soil "anchor points" across the entire concrete slab unit 41, significantly increasing the total contact area and mechanical interlocking interface between the lightweight soil and the concrete slab unit 41. The concrete slab unit 41 is "nail-in" constrained by the lightweight soil at any position and in any direction, eliminating weak areas of bond strength. This results in a comprehensive and balanced "volume interlocking" bond between the concrete slab unit 41 and the lightweight soil, significantly improving interlayer shear strength and pull-out strength.

[0054] In some implementations, the total area S1 of the multiple perforated slots 411 and the total area S of each concrete slab unit 41 satisfy: S≥3×S1. This ratio ensures that the area of ​​the solid portion of the concrete slab unit 41 accounts for at least two-thirds of the total area. This preserves sufficient concrete material to form a continuous and stable spatial load-bearing skeleton, enabling the concrete slab unit 41 to effectively bear and diffuse bending moments, shear forces, and compressive forces. It also prevents the concrete slab unit 41 from losing its reinforcing function due to severe weakening of its own stiffness caused by excessive openings. At the same time, the perforation rate of up to one-third can also effectively reduce the self-weight of the concrete slab unit 41 by about one-third, significantly contributing to the overall lightweighting goal of the structure and reducing the load on the foundation.

[0055] In some implementations, such as Figure 1 As shown, the thickness of the precast reinforced concrete slab interlayer 4 along the first direction X is L, satisfying: 5cm ≤ L ≤ 20cm. This thickness range allows the reinforcing mesh 42 to have a reasonable protective layer thickness within the slab, ensuring the durability of the reinforcing bars and effective anchorage and force transmission. Furthermore, the design of perforated grooves 411 within a thickness of 5-20cm ensures the formation of sufficiently deep lightweight soil "anchor columns," achieving effective three-dimensional interlocking, while the concrete ribs also maintain the necessary dimensions and strength.

[0056] It should be noted that precast reinforced concrete slab interlayers 4 with a thickness of less than 5cm will have significantly insufficient in-plane bending and shear stiffness, making it difficult to effectively undertake the core tasks of "diffusion of loads and suppression of deformation." It may resemble a thin sheet, prone to bending deformation or even cracking under stress, failing to form a reliable rigid reinforcement layer. 5cm is the minimum structural thickness to ensure the proper arrangement of the reinforcing mesh 42 within the slab and to form an effective synergistic load-bearing structure, ensuring its structural function. If the interlayer is too thick (e.g., >20cm), its own concrete weight will increase significantly, weakening the core advantage of the "lightweight" design of the entire system, while also increasing the load on the foundation, which partially deviates from the original intention of using aerated lightweight soil. Furthermore, concrete usage and cost are almost directly proportional to thickness; the 20cm upper limit is an economic threshold, providing sufficient stiffness while avoiding excessive material waste, making the technology cost-competitive.

[0057] In some implementations, such as Figure 1 As shown, along the first direction X, the spacing between two adjacent precast reinforced concrete slab layers 4 is H, satisfying: 50cm ≤ H ≤ 100cm. The 50-100cm spacing between adjacent precast reinforced concrete slab layers 4 ensures that each layer effectively and sufficiently constrains the underlying lightweight soil of a certain thickness, "binding" it into a stable composite layer. Multiple layers of precast reinforced concrete slab layers 4 are stacked at this spacing, dividing and strengthening the entire thick fill into a series of controllable wholes, completely eliminating the inherent risks of unconstrained large-volume fill.

[0058] It should be noted that if the spacing between two adjacent precast reinforced concrete slab mezzanines 4 is too small (e.g., <50cm), the lightweight soil fill layer between the two adjacent precast reinforced concrete slab mezzanines 4 will be too thin, resulting in excessive overlap of the constraint areas of the two adjacent precast reinforced concrete slab mezzanines 4, causing material waste and failing to fully utilize the advantages of multi-layer design. Furthermore, the post-cast strips of adjacent precast reinforced concrete slab mezzanines 4 need to be staggered to block vertical weak channels. A vertical spacing of 50-100cm provides sufficient space for this staggering, allowing force flow to be smoothly transmitted in a zigzag pattern without causing new stress concentration due to excessively abrupt force flow changes caused by too small a spacing.

[0059] If the spacing between two adjacent precast reinforced concrete slab interlayers 4 is too large (e.g., >100cm), the lightweight soil fill layer between the two adjacent precast reinforced concrete slab interlayers 4 will be too thick. This will cause the lateral restraint and vertical stress diffusion effect of a single precast reinforced concrete slab interlayer 4 on the excessively thick soil below to decrease significantly with depth. The middle area may still form a relatively weak zone, which cannot completely solve the problem of internal settlement and cracking of large-volume lightweight soil.

[0060] The construction steps for this bubble-bubble lightweight soil subgrade structure are as follows: After leveling the original ground, a base layer 1 is laid on the original ground. The base layer 1 is preferably a crushed stone layer. Then, a reverse filter geotextile is laid on the base layer 1, and a bottom steel mesh is built. Then, a layer of a certain thickness of aerated lightweight soil 3 is laid on the base layer 1. After the aerated lightweight soil 3 has initially set, a precast reinforced concrete slab interlayer 4 is placed on the initially set aerated lightweight soil 3. Then, the aerated lightweight soil 3 is filled again. After it has initially set, the next precast reinforced concrete slab interlayer 4 is placed, and then the aerated lightweight soil 3 is filled again. This process is repeated to complete the laying of the entire aerated lightweight soil 3. Finally, a top steel mesh is built on top of the aerated lightweight soil 3, and then the road structure layer 2 is laid.

[0061] It should be noted that during the laying process, the purpose of waiting for the initial setting of the air-bubbly lightweight soil layer 3 before placing the precast reinforced concrete slab interlayer 4 is to prevent the precast reinforced concrete slab interlayer 4 from settling or becoming unbalanced under gravity, thereby losing its load-bearing capacity; and after the initial setting of the lower air-bubbly lightweight soil layer 3, it can still be firmly bonded to the upper air-bubbly lightweight soil layer 3, so as to ensure the interface connection strength between the upper and lower air-bubbly lightweight soil layers 3 and avoid stress concentration that damages the plasticity inside the lightweight soil.

[0062] In other embodiments, to further prevent the precast reinforced concrete slab interlayer 4 from settling or becoming unbalanced under gravity, vertical steel bars (not shown) can be arranged in the base layer 1 to support the precast reinforced concrete slab interlayer 4.

[0063] In addition, such as Figure 1 As shown, along the second direction Y, concrete panels 5 are provided on both sides of the aerated lightweight soil layer 3 for support, and the concrete panels 5 are connected to the subgrade layer 1 to ensure sufficient support strength; in some embodiments, the precast reinforced concrete slab interlayer 4 can also be connected to the concrete panels 5 to further improve the compressive, shear, and flexural bearing capacity of the entire aerated lightweight soil subgrade structure. Figure 2 As shown, along the third direction Z, the air-bubbly lightweight soil layer 3 is supported on both sides by embankment fill. In order to ensure the stability of the interface connection between the air-bubbly lightweight soil layer 3 and the embankment fill, the surface of the air-bubbly lightweight soil layer 3 needs to be cleaned and sprayed with 5cm thick C25 concrete before pouring the air-bubbly lightweight soil layer 3.

[0064] In summary, the aerated lightweight soil subgrade structure proposed in this application utilizes precast reinforced concrete slab interlayers 4 spaced within the aerated lightweight soil layer 3. These precast reinforced concrete slab interlayers 4, composed of multiple individual concrete slabs 41 and a steel mesh 42, possess high strength and rigidity. Compared to the low-strength aerated lightweight soil, they act as a continuous rigid reinforcement, dividing and "clamping" the aerated lightweight soil layer 3. This significantly enhances the shear and tensile strength of the aerated lightweight soil subgrade structure, substantially improving its structural integrity and ensuring effective and uniform load transfer in the vertical direction, thereby improving the overall stability of the subgrade structure. Furthermore, the precast reinforced concrete slab interlayers 4... As a rigid horizontal barrier, it can prevent shrinkage or shear cracks that may occur inside the aerated lightweight soil from developing upwards, preventing them from reflecting to the pavement structure layer 2, avoiding large-scale cracking instability or subsidence, and ensuring driving comfort. At the same time, the combination of the precast reinforced concrete slab interlayer 4 and the aerated lightweight soil layer 3 can improve the deformation coordination of the entire fill, making it better able to adapt to differential settlement. This application significantly improves the shear and tensile bearing capacity of the entire aerated lightweight soil subgrade structure by setting the precast reinforced concrete slab interlayer 4, while improving the overall stiffness and deformation coordination of the aerated lightweight soil, so that the aerated lightweight soil subgrade structure can be applied to scenarios with higher bearing capacity requirements, and provides a greater safety reserve under the same geological conditions.

[0065] The above description is merely a preferred embodiment of this application. It should be noted that, for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of this application, and these improvements and substitutions should also be considered within the scope of protection of this application. The basic principles, main features, and advantages of this application have been shown and described above. For those skilled in the art, it is obvious that this application is not limited to the details of the above preferred embodiments. The embodiments should be considered exemplary and non-limiting. The scope of this application is defined by the appended claims rather than the foregoing description. Therefore, it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included within this application.

[0066] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in the embodiments can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A bubble-filled lightweight soil subgrade structure, having a first direction (X), characterized in that, It includes a subbase layer (1), a pavement structure layer (2), an aerated lightweight soil layer (3), and a precast reinforced concrete slab interlayer (4). Along the first direction (X), the subbase layer (1) and the pavement structure layer (2) are spaced apart, and the bubble-mixed lightweight soil layer (3) is located between the subbase layer (1) and the pavement structure layer (2); the precast reinforced concrete slab interlayer (4) is located within the bubble-mixed lightweight soil layer (3), and along the first direction (X), the precast reinforced concrete slab interlayer (4) is spaced apart from the subbase layer (1) and the pavement structure layer (2) respectively; The precast reinforced concrete slab interlayer (4) includes a concrete slab unit (41) and a steel mesh (42). The steel mesh (42) is at least partially connected to the concrete slab unit (41). There are multiple concrete slab units (41) arranged at intervals, and the multiple concrete slab units (41) are connected by the steel mesh (42).

2. The bubble-filled lightweight soil subgrade structure according to claim 1, characterized in that, The bubble-bubble lightweight soil subgrade structure also has a second direction (Y) and a third direction (Z); The precast reinforced concrete slab interlayer (4) is provided with a first post-pouring strip (401) and a second post-pouring strip (402). At least some of the concrete slab units (41) are spaced apart along the second direction (Y), and the first post-cast strip (401) is formed between two adjacent concrete slab units (41). At least some of the concrete slab units (41) are spaced apart along the third direction (Z), and a second post-cast strip (402) is formed between two adjacent concrete slab units (41). The steel mesh (42) is at least partially located in the first post-cast strip (401) and the second post-cast strip (402). The first direction (X), the second direction (Y), and the third direction (Z) are all perpendicular to each other.

3. The bubble-filled lightweight soil subgrade structure according to claim 2, characterized in that, There are multiple precast reinforced concrete slab interlayers (4), and the multiple precast reinforced concrete slab interlayers (4) are spaced apart along the first direction (X); Along the first direction (X), the first post-cast strips (401) on two adjacent precast reinforced concrete slab interlayers (4) are staggered, and the second post-cast strips (402) on two adjacent precast reinforced concrete slab interlayers (4) are staggered.

4. The bubble-filled lightweight soil subgrade structure according to claim 2, characterized in that, The steel mesh (42) includes a first steel bar (421) and a second steel bar (422) connected to each other. The first reinforcing bar (421) extends along the second direction (Y), and the first reinforcing bar (421) is at least partially inserted through the first post-cast strip (401). The second reinforcing bar (422) extends along the third direction (Z), and the second reinforcing bar (422) is at least partially inserted through the second post-cast strip (402).

5. The bubble-filled lightweight soil subgrade structure according to claim 4, characterized in that, The precast reinforced concrete slab interlayer (4) also includes a third steel bar (43) and a fourth steel bar (44). Along the second direction (Y), the third reinforcing bar (43) is spaced apart from the second reinforcing bar (422). The third reinforcing bar (43) is located within the first post-cast strip (401) and extends along the third direction (Z). The third reinforcing bar (43) is connected to the first reinforcing bar (421). Along the third direction (Z), the fourth reinforcing bar (44) is spaced apart from the first reinforcing bar (421). The fourth reinforcing bar (44) is located in the second post-cast strip (402) and extends along the second direction (Y). The fourth reinforcing bar (44) is connected to the second reinforcing bar (422).

6. The bubble-filled lightweight soil subgrade structure according to claim 4, characterized in that, Each of the concrete slab units (41) is provided with a hollow groove (411), which penetrates the concrete slab unit (41) along the first direction (X). Along the second direction (Y), at least a portion of the first reinforcing bar (421) passes through the hollow groove (411). Along the third direction (Z), at least a portion of the second reinforcing bar (422) passes through the hollow groove (411).

7. The bubble-filled lightweight soil subgrade structure according to claim 6, characterized in that, The hollowed-out grooves (411) are multiple and spaced apart.

8. The bubble-filled lightweight soil subgrade structure according to claim 7, characterized in that, The total area S1 of the plurality of hollow grooves (411) and the total area S of each concrete slab (41) satisfy: S≥3×S1.

9. The bubble-filled lightweight soil subgrade structure according to claim 1, characterized in that, The thickness of the precast reinforced concrete slab interlayer (4) along the first direction (X) is L, which satisfies: 5cm≤L≤20cm.

10. A bubble-filled lightweight soil subgrade structure according to claim 3, characterized in that, Along the first direction (X), the distance between two adjacent precast reinforced concrete slab interlayers (4) is H, which satisfies: 50cm≤H≤100cm.

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