A thick cushion foam light soil subgrade structure of a deep soft foundation road section
Patent Information
- Application Number
- CN202522601057.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-08
- Publication Date
- 2026-11-03
- Estimated Expiration
- 2035-12-08
AI Technical Summary
Traditional roadbeds in deep soft soil sections are prone to uneven settlement under vehicle loads and their own weight, leading to road surface cracking and traffic interruption. Furthermore, existing foamed lightweight soil requires baffles for restraint during installation, but these baffles are easily damaged, resulting in low construction efficiency.
By installing tie bars and connecting bars inside the casting trench and applying prestress through a tensioning device, combined with the split casting trench structure, the compressive strength of the foamed lightweight soil is improved and the construction efficiency is increased.
It enhances the compressive strength of foamed lightweight soil, improves construction efficiency, prevents lateral displacement of the subgrade structure, reduces settlement deformation, and improves the stability and durability of the road.
Smart Images
Figure CN224930896U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the technical field of road construction, specifically to a thick-layer foamed lightweight soil subgrade structure for deep soft soil road sections. Background Technology
[0002] Currently, as transportation infrastructure extends to coastal plains, river and lake sedimentary areas, and deltas, the foundations of deep soft soil road sections are often composed of silt and silty soil exceeding 5 meters in thickness. These foundations are characterized by high water content, large porosity, low bearing capacity, and high compressibility, directly impacting the stability and durability of the road structure. Under vehicle loads and their own weight, traditional roadbeds in deep soft soil sections are prone to uneven settlement and other defects, which can lead to pavement cracking, traffic disruption, and significantly increase maintenance costs and traffic risks.
[0003] To address road problems in deep soft soil foundation sections, foamed lightweight soil has gradually gained attention as a novel roadbed material. Utilizing its ultra-lightweight properties, foamed lightweight soil can significantly reduce the roadbed's self-weight, decrease the additional stress on the underlying soft soil, and fundamentally suppress settlement and deformation. Its high fluidity and self-compacting properties allow it to self-level and self-compact without vibration, filling complex geological voids and tightly adhering to the underlying soft soil and surrounding structures, preventing stress concentration caused by interface delamination. However, during the laying of foamed lightweight soil, baffles need to be installed at the road edges to constrain its boundaries. After the foamed lightweight soil has hardened and gained strength, the baffles need to be removed and moved to the next construction section. Removing the baffles can easily damage the foamed lightweight soil and results in low construction efficiency. Therefore, a new technical solution is needed to address these technical problems. Utility Model Content
[0004] This application proposes a thick-layer foamed lightweight soil subgrade structure for deep soft soil road sections. The subgrade is laid directly on the soft soil foundation layer using a pouring trench. Tie bars are then installed within the pouring trench, and prestress is applied to the tie bars using a tensioning device. Foamed lightweight soil is then poured into the pouring trench. This design allows the pouring trench to both constrain the edges of the foamed lightweight soil and enhance its compressive strength using the prestressed tie bars and connecting bars. This achieves both increased compressive strength and improved construction efficiency.
[0005] Therefore, this application provides a thick cushion layer foamed lightweight soil subgrade structure for deep soft soil road sections, including a casting groove set on the soft soil foundation layer, tie bars set in the casting groove, and connecting bars perpendicular to the tie bars. The foamed lightweight soil is poured in the casting groove, and a tensioning device for applying prestress to the tie bars is provided between the tie bars and the side wall of the casting groove. The tensioning device includes a tensioning rod fixedly connected to the tie bar and a nut threadedly connected to the tensioning rod. A tensioning hole is provided on the side wall of the casting groove. A tensioning rod is fixed at both ends of the tie bar. One end of the tensioning rod passes through the tensioning hole and is threadedly connected to the nut. The nut and tensioning rod are used to apply prestress to the tie bar.
[0006] By adopting the above technical solution: when pouring the foamed lightweight soil subgrade structure of this application, the pouring trench is first placed above the soft soil foundation layer. Then, the tie bar is moved to align the tension rod with the tension hole. After the tension rod passes through the tension hole, it is threaded with the nut. Then, a rotational force is applied to the nuts at both ends of the tie bar, so that the two nuts simultaneously apply prestress to the tie bar through the tension rod. Then, the connecting bar is set perpendicular to the tie bar, so that the tie bar and connecting bar are set in a grid pattern. Then, foamed lightweight soil is poured into the pouring trench to complete the pouring of foamed lightweight soil. This allows the pouring trench to both constrain the edge of the foamed lightweight soil and enhance the compressive strength of the foamed lightweight soil by using the prestressed tie bar and connecting bar. This achieves the purpose of both enhancing the compressive strength of the foamed lightweight soil and improving construction efficiency.
[0007] Preferably, the casting trough includes a casting base plate that abuts against the soft soil foundation layer and casting side plates that are perpendicular to the casting base plate. Two casting side plates are provided, and the two casting side plates are symmetrically arranged on both sides of the casting base plate. Tensioning holes are opened on the casting side plates, and a connecting device for splicing is provided between the casting side plates and the casting base plate.
[0008] By adopting the above technical solution, the casting trough is designed as a split structure, which allows the casting trough to be stacked during transportation, improving the convenience of transportation. When the casting trough is transported to the construction site, the casting base plate is first placed on top of the soft soil foundation layer, and then the casting side plate is moved to be perpendicular to the edge of the casting base plate. The casting side plate is connected to the casting base plate using a connecting device. The split casting trough improves the convenience of manual handling during the construction of the casting trough.
[0009] Preferably, the connecting device includes a connecting rod fixedly connected to the casting base plate and a connecting hole opened on the casting side plate, with the connecting plate and the connecting hole being inserted into each other.
[0010] By adopting the above technical solution: moving the pouring side plate to the top of the pouring top plate so that the connecting hole is aligned with the connecting rod, and then lowering the pouring side plate so that the connecting rod is inserted into the connecting hole, the splicing of the pouring side plate and the pouring bottom plate is completed. Furthermore, by using the positioning of the connecting rod and the connecting hole, the distance between the two pouring side plates meets the design dimensions.
[0011] Preferably, the connecting hole is connected to the tensioning hole, and the connecting rod has a through hole. When the connecting rod is fully inserted into the connecting hole, the through hole is connected to the tensioning hole, and the tensioning rod passes through the tensioning hole and the through hole.
[0012] By adopting the above technical solution: when the side plate is poured and the bottom plate is poured, the connecting rod is completely located in the connecting hole. At this time, the tensioning hole and the through hole are aligned. The tensioning rod passes through the tensioning hole and the through hole, which can not only determine whether the connecting rod is fully inserted into the connecting hole, but also use the tensioning rod to fix the connecting rod and the side plate, thus preventing the side plate from separating from the bottom plate.
[0013] Preferably, a positioning rod for inserting into the soft soil foundation layer is fixedly connected to the cast-in-place base plate, and the end of the positioning rod away from the cast-in-place base plate is provided with a tip for inserting into the soft soil foundation layer.
[0014] Preferably, the side wall of the positioning rod is fixedly connected with a number of anti-pickup spikes, and the end of the anti-pickup spikes away from the positioning rod is inclined upward.
[0015] By adopting the above technical solution: using positioning rods inserted into the soft soil foundation layer to fix the position of the pouring groove and the soft soil foundation layer, and then using anti-pick-out spikes to reduce the pouring base plate from being pulled out during installation, the stability of the connection between the pouring base plate and the soft soil foundation layer is improved, and the overall lateral displacement of the roadbed structure is prevented.
[0016] Preferably, the sides of the casting groove are provided with shoulder structures for protecting the sidewalls of the casting groove, and the shoulder structures abut against the sidewalls of the casting groove.
[0017] By adopting the above technical solution, the shoulder structure can protect the cast-in-place side plate and the tension rod on the cast-in-place side plate, and can also further prevent the overall lateral displacement of the roadbed structure.
[0018] Preferably, the top of the casting trough is provided with an isolation and seepage prevention layer, a stress buffer layer and a road structure layer from bottom to top.
[0019] By adopting the above technical solutions: using an isolation and seepage-proof layer to prevent water from penetrating the foamed lightweight soil and preventing its strength from decreasing due to changes in water content; using a stress buffer layer to buffer the stiffness difference between the foamed lightweight soil and the upper rigid pavement, uniformly transferring the load, avoiding stress concentration that could lead to pavement cracking; and using the pavement structure layer to bear the load on the pavement.
[0020] The working principle and beneficial effects of this application are as follows: 1. When casting the foamed lightweight soil subgrade structure of this application by setting up a casting groove, the casting groove is first placed above the soft soil foundation layer. Then, the tie bar is moved to align the tension rod with the tension hole. After the tension rod passes through the tension hole, it is threaded to the nut. Then, the nuts at both ends of the tie bar are simultaneously applied to the tie bar through the tension rod, so that the two nuts apply prestress to the tie bar at the same time. Then, the connecting bar is set perpendicular to the tie bar, so that the tie bar and the connecting bar are set in a grid pattern. Then, foamed lightweight soil is poured into the casting groove to complete the pouring of foamed lightweight soil. This allows the casting groove to both constrain the edge of the foamed lightweight soil and enhance the compressive strength of the foamed lightweight soil by using the prestressed tie bar and connecting bar. This achieves the purpose of both enhancing the compressive strength of the foamed lightweight soil and improving construction efficiency.
[0021] 2. By setting the casting trough as a split structure, the casting trough can be stacked during transportation, improving the convenience of transportation. When the casting trough is transported to the construction site, the casting base plate is first placed on the top of the soft soil foundation layer, and then the casting side plate is moved to be perpendicular to the edge of the casting base plate. The casting side plate is connected to the casting base plate using a connecting device. The split-type casting trough improves the convenience of manual handling during the construction of the casting trough.
[0022] 3. By setting positioning rods and inserting them into the soft soil foundation layer, the position of the pouring groove and the soft soil foundation layer is fixed. Then, anti-pick-out devices are used to reduce the risk of the pouring base plate being pulled out during installation, thereby improving the stability of the connection between the pouring base plate and the soft soil foundation layer and preventing the overall lateral displacement of the roadbed structure. Attached Figure Description
[0023] The present application will now be described in further detail with reference to the accompanying drawings and specific embodiments.
[0024] Figure 1 This is a structural schematic diagram of a thick-layer foamed lightweight soil subgrade structure for a road section with deep soft soil, as described in this application. Figure 2 This application shows a schematic diagram of the tensioning device. Figure 3 This is a schematic diagram of the grid-like structure formed by two layers of tie bars and connecting bars in this application; Figure 4 This is a schematic diagram of the actual connecting device and tensioning device of this application.
[0025] The technical features in the attached drawings are labeled as follows: 1. Soft soil foundation layer; 2. Pouring trench; 21. Pouring base slab; 22. Pouring side slab; 221. Tensioning hole; 3. Tie bar; 4. Connecting bar; 5. Tensioning device; 51. Tensioning rod; 52. Nut; 6. Connecting device; 61. Connecting hole; 62. Connecting rod; 621. Through hole; 7. Positioning rod; 71. Anti-prickling device; 8. Shoulder; 9. Isolation and seepage prevention layer; 10. Stress buffer layer; 20. Pavement structure layer. Detailed Implementation
[0026] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the embodiments of this application. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.
[0027] like Figures 1-3 As shown, this embodiment provides a thick-layer foamed lightweight soil subgrade structure for deep soft soil road sections, including a casting groove 2 set on a soft soil foundation layer 1, tie bars 3 set in the casting groove 2, and connecting bars 4 perpendicular to the tie bars 3. The foamed lightweight soil is poured into the casting groove 2. A tensioning device 5 for applying prestress to the tie bars 3 is set between the tie bars 3 and the side wall of the casting groove 2. The top of the casting groove 2 is provided with an isolation seepage prevention layer 9, a stress buffer layer 10, and a pavement structure layer 20 from bottom to top. Shoulder 8 structures for protecting the side walls of the casting groove 2 are set on both sides of the casting groove 2. The shoulder 8 structures abut against the side walls of the casting groove 2. In this application, there are two layers of tie bars 3 and two layers of connecting bars 4. Both layers of tie bars 3 and connecting bars 4 are set in a grid pattern in the casting groove 2. Each layer of tie bars 3 is provided with a corresponding tensioning device 5.
[0028] like Figures 2-3 As shown, the tensioning device 5 includes a tensioning rod 51 fixedly connected to the tie bar 3 and a nut 52 threadedly connected to the tensioning rod 51. The side wall of the casting groove 2 is provided with a tensioning hole 221. A tensioning rod 51 is fixed at both ends of the tie bar 3. One end of the tensioning rod 51 passes through the tensioning hole 221 and is threadedly connected to the nut 52. The nut 52 and the tensioning rod 51 are used to apply prestress to the tie bar 3. A relaxation washer is provided between the nut 52 and the side wall of the casting groove 2.
[0029] like Figures 3-4As shown, the casting trough 2 includes a casting base plate 21 that abuts against the soft soil foundation layer 1 and casting side plates 22 that are perpendicular to the casting base plate 21. There are two casting side plates 22, which are symmetrically arranged on both sides of the casting base plate 21. Tensioning holes 221 are opened on the casting side plates 22. A connecting device 6 for splicing is provided between the casting side plates 22 and the casting base plate 21. The connecting device 6 includes a connecting rod 62 that is fixedly connected to the casting base plate 21 and a connecting hole 61 opened on the casting side plate 22. The connecting plate is inserted into the connecting hole 61. The connecting hole 61 communicates with the tensioning hole 221. A through hole 621 is opened on the connecting rod 62. When the connecting rod 62 is fully inserted into the connecting hole 61, the through hole 621 communicates with the tensioning hole 221. The tensioning rod 51 passes through the tensioning hole 221 and the through hole 621.
[0030] like Figure 4 As shown, a positioning rod 7 for inserting into the soft soil foundation layer 1 is fixedly connected to the cast base plate 21. The end of the positioning rod 7 away from the cast base plate 21 is provided with a tip for inserting into the soft soil foundation layer 1. Several anti-pulling spikes 71 are fixedly connected to the side wall of the positioning rod 7. The end of the anti-pulling spikes 71 away from the positioning rod 7 is inclined upward.
[0031] The basic principle of this embodiment is as follows: When using the thick cushion layer foam lightweight soil subgrade structure for deep soft soil road sections of this application, firstly, the cast-in-place base plate 21 is placed at the top of the soft soil foundation layer 1 according to the preset position, so that the cast-in-place base plate 21 drives the positioning rod 7 to insert into the soft soil foundation layer 1. Then, the cast-in-place side plate 22 is moved to the top of the cast-in-place top plate, so that the connecting hole 61 is aligned with the connecting rod 62. Then, the cast-in-place side plate 22 is lowered, so that the connecting rod 62 is inserted into the connecting hole 61, completing the splicing of the cast-in-place side plate 22 and the cast-in-place base plate 21. The tie bar 3 is moved to drive the tension rod 51 to align with the tension hole 221. The tension rod 51 is passed through the tension hole 221 and then threadedly connected to the nut 52. If the position of the connecting rod 62 is encountered, the tension rod 51 passes through the tension hole 221 and the through hole 621 on the connecting rod 62 and then threadedly connected to the nut 52. Then, the threads at both ends of the tie bar 3 are simultaneously tightened. The nut 52 applies a rotational force, causing both nuts 52 to simultaneously apply prestress to the tie bar 3 through the tension rod 51. Then, the connecting bar 4 is set perpendicular to the tie bar 3, making the tie bar 3 and connecting bar 4 form a grid. Then, foamed lightweight soil is poured into the pouring trench 2 to complete the pouring of foamed lightweight soil. Then, a road shoulder 8 is set on the outer wall of the pouring side plate 22 to protect the pouring side plate 22 and the tension rod 51. After the foamed lightweight concrete has solidified and reached the predetermined strength, the isolation seepage prevention layer 9, stress buffer layer 10 and road structure layer 20 are constructed sequentially at the top of the pouring trench 2. In summary, through the above steps, the pouring trench 2 can both constrain the edge of the foamed lightweight soil pouring and enhance the compressive strength of the foamed lightweight soil by using the prestressed tie bar 3 and connecting bar 4, thus achieving the purpose of both enhancing the compressive strength of the foamed lightweight soil and improving construction efficiency.
[0032] The above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.
Claims
1. A thick-layer foamed lightweight soil subgrade structure for deep soft soil road sections, characterized in that, It includes a pouring groove (2) set on the soft soil foundation layer (1), tie bars (3) set in the pouring groove (2) and connecting bars (4) perpendicular to the tie bars (3). Foamed lightweight soil is poured in the pouring groove (2). A tensioning device (5) for applying prestress to the tie bars (3) is set between the tie bars (3) and the side wall of the pouring groove (2). The tensioning device (5) includes a tensioning rod (51) fixedly connected to the tie bar (3) and a nut (52) threadedly connected to the tensioning rod (51). The side wall of the casting groove (2) is provided with a tensioning hole (221). A tensioning rod (51) is fixed at both ends of the tie bar (3). One end of the tensioning rod (51) passing through the tensioning hole (221) is threadedly connected to the nut (52).
2. The thick-layer foamed lightweight soil subgrade structure for deep soft soil road sections according to claim 1, characterized in that, The casting groove (2) includes a casting base plate (21) that abuts against the soft soil foundation layer (1) and a casting side plate (22) that is perpendicular to the casting base plate (21). There are two casting side plates (22), which are symmetrically arranged on both sides of the casting base plate (21). Tensioning holes (221) are opened on the casting side plates (22). A connecting device (6) for splicing is provided between the casting side plates (22) and the casting base plate (21).
3. The thick-layer foamed lightweight soil subgrade structure for deep soft soil road sections according to claim 2, characterized in that, The connecting device (6) includes a connecting rod (62) fixedly connected to the casting base plate (21) and a connecting hole (61) opened on the casting side plate (22), and the connecting plate and the connecting hole (61) are inserted into each other.
4. The thick-layer foamed lightweight soil subgrade structure for deep soft soil road sections according to claim 3, characterized in that, The connecting hole (61) is connected to the tensioning hole (221). The connecting rod (62) has a through hole (621). When the connecting rod (62) is fully inserted into the connecting hole (61), the through hole (621) is connected to the tensioning hole (221). The tensioning rod (51) passes through the tensioning hole (221) and the through hole (621).
5. The thick-layer foamed lightweight soil subgrade structure for deep soft soil road sections according to claim 2, characterized in that, A positioning rod (7) for inserting into the soft soil foundation layer (1) is fixedly connected to the cast base plate (21). The end of the positioning rod (7) away from the cast base plate (21) is provided with a tip for inserting into the soft soil foundation layer (1).
6. The thick-layer foamed lightweight soil subgrade structure for deep soft soil road sections according to claim 5, characterized in that, The side wall of the positioning rod (7) is fixedly connected with several anti-pulling spikes (71), and the anti-pulling spikes (71) are inclined upward at the end away from the positioning rod (7).
7. The thick-layer foamed lightweight soil subgrade structure for deep soft soil road sections according to claim 1, characterized in that, The casting groove (2) is provided with shoulder (8) structures on both sides for protecting the side walls of the casting groove (2), and the shoulder (8) structures abut against the side walls of the casting groove (2).
8. The thick-layer foamed lightweight soil subgrade structure for deep soft soil road sections according to claim 1, characterized in that, The top of the casting trough (2) is provided with an isolation and seepage prevention layer (9), a stress buffer layer (10) and a road structure layer (20) from bottom to top.