Broadening structure suitable for reconstruction and extension project in area with limited occupied area and construction method
By setting up multi-layered connecting components with composite foundations and cell-filled widening zones in the reconstruction and expansion projects of areas with limited land use, the problem of reinforcement blind spots at the junction of new and old roadbeds was solved, the bearing capacity and shear strength of the roadbed were enhanced, uneven settlement was prevented, and the durability of the pavement structure and driving safety were improved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-26
- Publication Date
- 2026-04-10
AI Technical Summary
In existing technologies, there are reinforcement blind spots at the junction of the old and new roadbeds in the reconstruction and expansion projects in areas with limited land use, which leads to uneven settlement of the roadbed outside the existing hard shoulder, affecting the durability of the pavement structure and driving safety.
A composite foundation and a cell filler widening zone are set up on the outside of the original roadbed. A dual-medium connection zone is formed through multi-layer connecting components (including connecting layers and reinforced gabions) to enhance the shear strength and integrity of the contact surface between the new and old roadbeds. The load is also evenly distributed through the grid structure of the reinforced gabions.
It effectively solves the problem of reinforcement blind spots, reduces differential settlement between new and old roadbeds, improves the durability and service life of the pavement structure, and ensures driving safety and comfort. At the same time, it strengthens the permeability of the gabions to prevent the roadbed from softening and enhances the stability of the original roadbed.
Smart Images
Figure CN121827165A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of road engineering technology, and in particular to a widening structure and construction method applicable to the reconstruction and expansion projects in areas with limited land. Background Technology
[0002] In the construction of highway reconstruction, expansion and widening projects, in order to meet the traffic demand brought about by the increase in traffic flow, it is often necessary to add a new roadbed on one or both sides of the existing road to widen the road surface. Among them, the slope grading process is widely used in the filling construction of new roadbeds due to its convenient construction and strong adaptability. When constructing a new roadbed using the slope embankment method, the self-weight load of the new roadbed exhibits a dispersed transmission characteristic, which can be divided into two parts: one part of the load acts directly on the newly added foundation area, while the other part of the load is transferred to the existing roadbed outside the hard shoulder and its underlying foundation through stress diffusion in the roadbed soil. However, current reinforcement solutions for this type of new-old roadbed connection have significant shortcomings: on the one hand, the step excavation scheme is a commonly used interface treatment method in the construction of new-old roadbed connection, but its effect is limited to enhancing the shear strength and integrity of the contact surface between the new and old roadbeds, and it cannot effectively reinforce the existing roadbed outside the hard shoulder and its underlying foundation involved in load transmission; on the other hand, conventional foundation treatment measures such as surcharge preloading and pile-net composite foundations often only cover the newly added foundation area from the toe of the old roadbed slope to the toe of the new roadbed slope, leaving the existing roadbed outside the hard shoulder and its underlying foundation outside the reinforcement scope, forming a significant reinforcement blind spot.
[0003] The existence of the aforementioned reinforcement blind spots makes the outer subgrade of the existing hard shoulder prone to uneven settlement under the self-weight of the new subgrade and subsequent traffic loads. This uneven settlement will further lead to cracking, subsidence and other defects in the pavement structure, which will not only seriously affect the durability and service life of the pavement structure, but also pose a great threat to driving safety and comfort. Summary of the Invention
[0004] Based on the above analysis, the present invention aims to provide a widening structure and construction method suitable for reconstruction and expansion projects in areas with limited land area, in order to solve at least one of the following problems in the prior art: the existing roadbed outside the existing hard shoulder has a reinforcement blind zone, which easily leads to uneven settlement and causes cracking and subsidence of the pavement structure; the new and old roadbeds have large differential settlements along the transverse and longitudinal directions of the roadbed; and there is no effective connection between the new and old roadbeds.
[0005] The objective of this invention is mainly achieved through the following technical solutions.
[0006] This invention provides a widening structure suitable for reconstruction and expansion projects in areas with limited land area, comprising a composite foundation, a cell-filled widening area, and a widened road surface stacked sequentially from bottom to top. The composite foundation is located outside the original foundation, and the cell-filled widening area is located outside the original roadbed. The existing roadbed has a dual-medium connection zone, which includes a connection component. The connection component includes a connection layer and a reinforcing gabion stacked from bottom to top.
[0007] Furthermore, the connecting layer and the reinforcing gabion are in close contact.
[0008] Furthermore, the connecting components are multi-layered, and the multi-layered connecting components are evenly arranged along the vertical direction.
[0009] Furthermore, the length of the multi-layer connecting components gradually increases from bottom to top.
[0010] The present invention also provides a construction method for widening structures applicable to the renovation and expansion projects in areas with limited land area, for use in the construction of the aforementioned widening structures applicable to the renovation and expansion projects in areas with limited land area.
[0011] Furthermore, the construction method includes the following steps: Step 1: Complete the construction of the composite foundation on the side of the existing foundation; Step 2: Excavate a rectangular foundation trench on the outside of the existing roadbed, and construct the reinforcing gabions and connecting layer in sequence in the rectangular foundation trench; Step 3: Complete the construction of the cell filler widening area and the widened road surface on the existing roadbed.
[0012] Furthermore, the following steps are included before step 2: Determine the actual anchorage length of the multi-layer connection assembly.
[0013] Further, determining the actual anchorage length of the multi-layer connection assembly includes the following steps: Step a: In the multi-layer connection components, define the i-th layer connection component as the connection component to be determined, where i is any positive integer from 1 to n, and calculate the minimum anchorage length of the connection layer to be determined; Step b: Calculate the overall stability safety factor of the dual-medium junction area; Step c: Determine whether the overall stability safety factor of the dual-medium junction area is above the safety factor threshold; If so, the minimum anchorage length of the connection layer to be determined shall be taken as the actual anchorage length of the connection layer to be determined. If not, then redetermine the anchorage length. If the anchorage length is greater than the minimum anchorage length, recalculate the overall stability safety factor of the dual-medium connection area.
[0014] Furthermore, in step c, the safety factor threshold is 1.2.
[0015] Furthermore, in step b, the overall stability safety factor of the dual-medium connection zone is calculated under the condition that the widened area of the cell packing is regarded as an integral rigid structure and the friction effect between the widened area of the cell packing and the composite foundation is not considered.
[0016] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects: A) The widening structure provided by this invention, applicable to the reconstruction and expansion projects in areas with limited land area, can effectively solve the problem of reinforcement blind spots in the original roadbed outside the existing hard shoulder by setting a dual-medium connection zone in the original roadbed, enhance the bearing capacity of the original roadbed, and make the widening zone of the cell filler effectively connected with the original roadbed, reducing the differential settlement of the new and old roadbeds along the transverse and longitudinal directions of the roadbed.
[0017] B) The widening structure provided by this invention, applicable to reconstruction and expansion projects in areas with limited land area, features a tight contact between the connecting layer and the reinforced gabion in the dual-medium connection zone. This further enhances the shear strength and integrity of the contact surface between the new and old roadbeds, and effectively reinforces the original roadbed outside the existing hard shoulder, preventing uneven settlement under the self-weight load of the new roadbed and subsequent traffic loads. This avoids cracking, subsidence, and other defects in the pavement structure, improves the durability and service life of the pavement structure, and ensures driving safety and comfort.
[0018] C) The widening structure provided by this invention, suitable for reconstruction and expansion projects in areas with limited land area, features a tight contact between the connecting layer and the reinforcing gabion. This not only enhances the shear strength of the contact surface between the new and old roadbeds but also distributes the load evenly to the original roadbed through the grid structure of the reinforcing gabion, further reducing the probability of uneven settlement. The stone filling material in the reinforcing gabion also has good permeability, effectively draining water from the roadbed and preventing roadbed softening caused by water accumulation, thereby further improving the stability and durability of the original roadbed.
[0019] D) The widening structure provided by this invention, applicable to the reconstruction and expansion projects in areas with limited land area, features an increasing length of multi-layer connecting components, enabling each connecting component to more accurately and effectively reinforce the original roadbed according to its location and stress characteristics.
[0020] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages may become apparent from the description or be learned by practicing the invention. The objects and other advantages of this invention can be realized and obtained through the embodiments described and the accompanying drawings, which are particularly pointed out. Attached Figure Description
[0021] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts. Figure 1 This is a schematic diagram of the widening structure provided in Embodiment 1 of the present invention, applicable to the renovation and expansion projects in areas with limited land area. Figure 2 This is a schematic diagram of the connecting components in the widening structure provided in Embodiment 1 of the present invention, which is applicable to the renovation and expansion project in a land-constrained area. Figure 3 This is a schematic diagram of the structure of the enlarged area of the cell packing in the enlarged structure provided in Embodiment 2 of the present invention, which is applicable to the renovation and expansion project in a land-constrained area. Figure 4 This is a schematic diagram of the structure of the gabion connector in the widened structure of the present invention, which is applicable to the renovation and expansion project of the land-limited area. (This is a second embodiment of the present invention.) Figure 5 This is a schematic diagram of the structure of the grid fixing rod in the widened structure of the present invention, which is applicable to the renovation and expansion project of the land-limited area. (This is a second embodiment of the present invention.) Figure 6 This is a flowchart of a construction method for a widened structure applicable to the renovation and expansion project in a land-constrained area, as provided in Embodiment 3 of the present invention.
[0022] Figure label: 1-Composite foundation; 11-Composite pile; 12-Warp-knitted composite layer; 13-Foundation gabion; 14-Anti-silting crushed stone cushion layer; 15-Soft soil layer; 2-Cell fill widening zone; 21-Vertical panel; 22-Three-dimensional cell; 23-Wide fill layer; 24-Cell gabion connector; 241-Connecting block; 242-Cell insertion slot; 243-Gabion insertion slot; 244-Rack body; 245-Ratchet; 246-Pawl; 247-Cell fixing rod; 248-Axial groove; 3-Wide road surface; 4-Connecting layer; 5-Reinforced gabion; 6-Existing roadbed; 7-Existing foundation. Detailed Implementation
[0023] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which constitute a part of the present invention and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.
[0024] Example 1 This embodiment provides a widening structure suitable for land-constrained area renovation and expansion projects. See [link to relevant documentation]. Figure 1 It includes a composite foundation 1, a cell-filled widening zone 2, and a widened road surface 3, which are stacked sequentially from bottom to top. The composite foundation 1 is located outside the original foundation 7, and the cell-filled widening zone 2 is located outside the original roadbed 6.
[0025] Among them, the original roadbed 6 has a dual-medium connection zone, see Figure 2 The dual-medium connection zone includes a multi-layer connection component, which includes a connection layer 4 and a reinforcing gabion 5 stacked sequentially from bottom to top, and the two are in close contact.
[0026] Compared with existing technologies, the widening structure provided in this embodiment, applicable to reconstruction and expansion projects in areas with limited land area, effectively solves the problem of reinforcement blind spots in the original roadbed 6 outside the existing hard shoulder by setting a dual-medium connection zone in the original roadbed, thereby enhancing the bearing capacity of the original roadbed 6 and enabling the grid-filled widening zone 2 to form an effective connection with the original roadbed 6, reducing the differential settlement of the new and old roadbeds along the transverse and longitudinal directions. On the other hand, the connection layer 4 and the reinforced gabion 5 in the dual-medium connection zone are in close contact, which can further enhance the shear strength and integrity of the contact surface between the new and old roadbeds, and effectively reinforce the original roadbed 6 outside the existing hard shoulder, preventing uneven settlement under the self-weight load of the new roadbed and subsequent traffic loads, thus avoiding cracking, subsidence and other defects in the pavement structure, improving the durability and service life of the pavement structure, and ensuring driving safety and comfort. On the other hand, the close contact between the connecting layer 4 and the reinforcing gabion 5 can not only enhance the shear strength of the contact surface between the new and old roadbeds, but also distribute the load evenly to the original roadbed through the grid structure of the reinforcing gabion, further reducing the probability of uneven settlement. The stone filling material in the reinforcing gabion 5 also has good permeability, which can effectively drain the water in the roadbed and prevent the softening of the roadbed caused by water accumulation, thereby further improving the stability and durability of the original roadbed 6.
[0027] To further address the issue of uneven settlement in the original roadbed 6, the length of the multi-layer connecting components (i.e., the lateral length embedded in the original roadbed 6) gradually increases from bottom to top. This incremental length arrangement of the multi-layer connecting components allows each layer to provide more precise and effective reinforcement to the original roadbed 6 based on its location and stress characteristics.
[0028] Specifically, the shorter connecting components at the bottom primarily reinforce the shallow areas of the existing roadbed 6, preventing localized settlement under load. The longer connecting components at the top, however, penetrate deeper into the existing roadbed 6, reinforcing these deeper areas and enhancing their load-bearing capacity. This progressively longer arrangement of connecting components creates a layered reinforcement system, effectively improving the overall stability and settlement resistance of the existing roadbed 6.
[0029] Example 2 This embodiment provides a widening structure for land-constrained area renovation and expansion projects. Its structure is basically the same as the widening structure for land-constrained area renovation and expansion projects provided in Embodiment 1, with the difference being: Specifically, the structure of the widened area 2 of the cell packing includes a vertical panel 21, a three-dimensional cell 22 and a widened packing layer 23. The multiple layers of three-dimensional cell 22 and the multiple layers of widened packing layer 23 are stacked alternately to form a reinforced laminated structure. The vertical panel 21 is located on the outside of the reinforced laminated structure in the vertical direction.
[0030] To address the issue of poor connection stability between the reinforced gabion 5 and the three-dimensional cell 22, the aforementioned cell filling widening zone 2 also includes a gabion connector 24, see [link / details]. Figure 3 The three-dimensional gabion 22 is detachably connected to the reinforced gabion 5 via gabion connector 24.
[0031] Specifically, see Figure 4 The gabion connector 24 includes a connecting block 241 and a gabion winding rod. A long strip-shaped gabion insertion groove 242 is opened on one side of the connecting block 241, and a hexagonal gabion insertion groove 243 is opened on the other side of the connecting block 241. A tensioning shaft insertion hole is opened in the connecting block 241 along the longitudinal direction. The gabion winding rod is inserted into the tensioning shaft insertion hole and is rotatably connected to the connecting block 241. The gabion insertion groove 242 communicates with the tensioning shaft insertion hole.
[0032] During implementation, the sheet-like structure at the end of the three-dimensional cell 22 passes through the cell insertion slot 242 and is fixedly connected to the cell winding rod; rotating the cell winding rod causes the three-dimensional cell 22 to be tensioned in the direction of the cell winding rod, thus achieving tensioning of the three-dimensional cell 22; at the same time, the cage mesh of the reinforcing gabion 5 is inserted into the gabion insertion slot 243 and the cage mesh is fixedly connected to the gabion insertion slot 243, thus completing the connection between the reinforcing gabion 5 and the cell gabion connector 24.
[0033] In this way, by setting up the gabion connector 24, a multi-locking system of physical positioning, mechanical connection, and unidirectional tension is constructed, which enables a detachable and stable connection between the three-dimensional gabion 22 and the reinforced gabion 5. Compared with traditional simple overlapping or bolted connections, the connection strength and stability are effectively improved, solving the problem of insufficient connection strength from the structural root. During road widening construction, the tension of the three-dimensional gabion 22 can be flexibly adjusted according to actual needs to ensure that it is tightly bonded to the vertical panel 21 and the widened filling layer 23, jointly bearing the upper load and effectively reducing deformation or damage caused by unstable connection.
[0034] To achieve a fixed connection between the cell winding rod and the sheet-like structure at the end of the three-dimensional cell 22, for the structure of the cell winding rod, specifically, see [link to relevant documentation]. Figure 5It includes a rod 244, a ratchet 245, a pawl 246, and a cell fixing rod 247. The rod 244 has an axial groove 248 along its axial direction. One end of the cell fixing rod 247 is fixedly connected to one side of the axial groove 248, while the other end of the cell fixing rod 247 is suspended and has a gap with the other side of the axial groove 248. The ratchet 245 is sleeved on one end of the rod 244, and the pawl 246 is mounted on a connecting block 241, with the ratchet 245 and pawl 246 engaging. Correspondingly, bolt holes are formed in the plate-like structure at the end of the three-dimensional cell 22. The sheet-like structure at the end of the three-dimensional cell 22 passes through the cell insertion groove 242 and is inserted into the gap between the cell fixing rod 247 and the wall of the axial groove 248. The bolt hole corresponds to the position of the cell fixing rod 247. At this time, rotating the rod body 244 will insert the cell fixing rod 247 into the bolt hole, realizing the fixed connection of the sheet-like structure cell winding rod at the end of the three-dimensional cell 22. Continuing to rotate the rod body 244 will cause the sheet-like structure at the end of the three-dimensional cell 22 to wind around the rod body 244, realizing the tensioning of the three-dimensional cell 22. When the three-dimensional cell 22 reaches the preset tension, the pawl 246 is inserted into the ratchet 245 to realize the tensioning and fixing of the three-dimensional cell 22.
[0035] In this way, the structured grid winding rod achieves a stable and fixed connection between the sheet-like structure at the end of the three-dimensional grid 22 and the grid winding rod. During the rotation of the rod 244, the grid fixing rod 247 is precisely inserted into the bolt hole, completing not only initial positioning and connection, but also, as the rod 244 continues to rotate, the sheet-like structure at the end of the three-dimensional grid 22 gradually winds around the rod 244, achieving gradual tensioning of the three-dimensional grid 22. When the tension reaches the preset value, the pawl 246 quickly inserts into the ratchet 245, forming a reliable mechanical lock, thus ensuring the stability of the three-dimensional grid 22 under tension. Simultaneously, the tensioning process of this grid winding rod is controllable and easy to operate, allowing construction personnel to precisely adjust the tension of the three-dimensional grid 22 according to actual needs to meet construction requirements under different working conditions.
[0036] Similarly, in order to further solve the problem of unstable connection between the gabion mesh of the reinforced gabion 5 and the gabion connector 24, the gabion connector 24 also includes a gabion connecting plate. After the gabion mesh of the reinforced gabion 5 is inserted into the gabion insertion groove 243, the gabion connecting plate is fastened to the gabion insertion groove 243, so that the gabion mesh of the reinforced gabion 5 is located between the connecting block 241 and the gabion connecting plate. The three are stably connected by bolts. Through the pressing action of the gabion connecting plate, the gabion mesh of the reinforced gabion 5 can be effectively prevented from coming out of the gabion insertion groove 243 when under stress, thereby enhancing the reliability of the connection.
[0037] The structure of the composite foundation 1 includes composite piles 11, warp-knitted composite layer 12, foundation gabion 13, anti-siltation crushed stone cushion layer 14, and soft soil layer 15. The composite piles 11 are located in the soft soil layer 15 and are set in a vertical direction. A receiving groove is provided on the upper surface of the soft soil layer 15 and between two adjacent composite piles 11. A continuous warp-knitted composite layer 12 is laid on the upper surface of the soft soil layer 15, as well as on the walls and bottom of the receiving groove. The foundation gabion 13 is placed on the warp-knitted composite layer 12 in the receiving groove. The anti-siltation crushed stone cushion layer 14 is laid on the foundation gabion 13 and the warp-knitted composite layer 12 on the surface.
[0038] The anti-clogging crushed stone cushion layer 14 includes graded crushed stone and filling material filling the gaps between the graded crushed stone. The composition of the filling material by mass parts includes 1-2 parts of N,N′methylenebisacrylamide, 22-25 parts of acrylamide monomer, 3-6 parts of bentonite, 0.05-0.2 parts of potassium ferricyanide and 0.5-1.5 parts of potassium persulfate. Thus, the aforementioned anti-clogging crushed stone cushion layer 14 is mainly composed of graded crushed stone, with a mixture mainly composed of acrylamide monomer and N,N′-methylenebisacrylamide filling the gaps between the graded crushed stone. The raw materials of the filling material undergo a chemical reaction in the gaps between the graded crushed stone to form a three-dimensional complex in-situ gel network, which can efficiently intercept fine soil particles, significantly reduce the risk of clogging of the anti-clogging crushed stone cushion layer 14, and extend the service life of the anti-clogging crushed stone cushion layer 14. At the same time, due to the porosity and incomplete filling of the three-dimensional complex in-situ gel network, the overall high permeability of the clogging crushed stone cushion layer can be guaranteed, and the drainage capacity is not fundamentally affected. In addition, due to the elasticity of the gel network, it can adapt to the deformation of the composite foundation and still maintain the barrier function after deformation, and is not prone to brittle failure.
[0039] Example 3 This embodiment provides a construction method for widening structures applicable to land-constrained area renovation and expansion projects, which is used for the construction of widening structures applicable to land-constrained area renovation and expansion projects provided in Embodiment 1 or Embodiment 2.
[0040] Specifically, see Figure 6 The construction method includes the following steps: Step 1: Complete the construction of composite foundation 1 on the side of the existing foundation 7; Step 2: Excavate a rectangular foundation trench on the outside of the existing roadbed 6, and construct the reinforcing gabion 5 and the connecting layer 4 in sequence in the rectangular foundation trench; Step 3: Complete the construction of the cell filling widening zone 2 and the widened road surface 3 on the existing roadbed 6.
[0041] Compared with the prior art, the beneficial effects of the construction method for widening structures in land-constrained area renovation and expansion projects provided in this embodiment are basically the same as those of the widening structure in land-constrained area renovation and expansion projects provided in Embodiment 1, and will not be described in detail here.
[0042] In order to enable the construction of composite foundation 1, for the structure of Embodiment 2, step 1 above includes the following steps. Step 11: According to the design drawings, mark the pile positions of the composite piles 11 on the soft soil layer 15, and complete the construction of the composite piles 11 in the soft soil layer 15 using appropriate pile forming technology. Step 12: Open a receiving trench on the upper surface of the soft soil layer 15 and between two adjacent composite piles 11. Lay a continuous warp-knitted composite layer 12 on the upper surface of the soft soil layer 15 and on the walls and bottom of the receiving trench to ensure the flatness of the warp-knitted composite layer 12. Step 13: Place the foundation gabion 13 into the receiving trough; Step 14: Lay the foundation gabion 13 and the warp-knitted composite layer 12 on the surface and the anti-clogging crushed stone cushion layer 14 to ensure that the laying thickness, compaction degree and flatness meet the requirements.
[0043] It is understood that, for the structure of Embodiment 2, the construction of the cell packing widening zone 2 in step 3 above includes the following steps: Step 31: Install a vertical panel 21 on the side of the anti-siltation crushed stone subbase 14 away from the original roadbed 6; Step 32: Between the original roadbed 6 and the vertical panel 21, lay multiple alternating layers of widened filler 23 and three-dimensional grid 22 on the surface of the anti-clogging crushed stone cushion layer 14. During the laying of the three-dimensional grid 22, the ends of the three-dimensional grid 22 are connected to the reinforced gabion 5 through the grid gabion connector 24.
[0044] To address the issue of unreasonable length settings for connecting components, the following steps are included before step 2 above: Determine the actual anchorage length of the multi-layer connection assembly.
[0045] Specifically, determining the actual anchorage length of multi-layer connection components includes the following steps: Step a: In the multi-layer connecting components, define the i-th layer connecting component as the connecting component to be determined, where i is any positive integer from 1 to n, and the minimum anchorage length of the connecting layer to be determined is... The calculation formula is as follows: ; ; In the formula: The unit weight of the original roadbed fill material, kN / m 3 ; The specific weight of the packing in the widened zone of the cell packing, in kN / m³. 3 ; The additional load acting on the connection layer to be determined is kN / m 2 ; The friction coefficient of the upper surface of the bonding layer to be determined; The friction coefficient of the lower surface of the bonding layer to be determined; The embedment depth of the connecting layer to be determined is in meters (m). It is the ratio of the maximum deflection of the three-dimensional cell after flexural deformation in the widened area of the cell packing to the width of 1 / 2 of the widened area of the cell packing; l is the width of the geocell along the cross section of the line in the geocell widening zone of the geocell filler, in meters; E represents the elastic modulus of the geocell in the geocell widening zone, in kPa; h represents the thickness of the bonding layer to be determined, in meters. h c The height of the geocell in the geocell expansion zone of the geocell filler, in meters; D represents the node spacing of geocells in the geocell expansion zone, in meters; d 50 The median particle size (m) of the geocell filler in the geocell filler widening zone; Q i The vertical stress at the joint layer under vehicle load, in kPa, is to be determined. L c The width of the load arrangement used in structural calculations, in meters; L ci For depth z i The stress diffusion width at the point, in meters, is calculated using the following formula; When Z i +H'≤2b c At that time, L ci =L c +H'+z i When Z i +H'>2b c At that time, L ci =L c +b c +(H'+z i ) / 2 H' is the height from the topmost connecting layer to the widened road surface, in meters; b c The distance from the back of the vertical panel to the edge of the original roadbed is in meters (m).
[0046] Step b: Treating the widened zone 2 of the cell packing as a rigid structure, and disregarding the frictional effect between the widened zone 2 of the cell packing and the composite foundation 1, calculate the overall stability safety factor of the dual-medium connection zone. The formula for calculating the overall stability safety factor of the dual-medium connection zone is as follows: ; In the formula: K is the overall stability safety factor of the dual-medium junction area; M a The overturning moment under active earth pressure is expressed in kN·m. M b The overturning moment in the dual-medium junction zone is kN·m; The unit weight of the original roadbed fill material, kN / m 3 ; H is the height of the original roadbed, in meters; The internal friction angle of the fill material in the original roadbed, in °; The interfacial friction angle between the original roadbed and the widened area of the cell filler, in °; The embedment depth of the connecting layer to be determined is in meters (m). The additional load acting on the connection layer to be determined is kN / m 2 ; The friction coefficient of the upper surface of the bonding layer to be determined; The friction coefficient of the lower surface of the bonding layer to be determined.
[0047] Step c: Determine whether the overall stability safety factor of the dual-medium junction area is above the safety factor threshold (e.g., 1.2 in the specification); If so, the minimum anchorage length of the connection layer to be determined shall be taken as the actual anchorage length of the connection layer to be determined. If not, then redetermine the anchorage length. If the anchorage length is greater than the minimum anchorage length, recalculate the overall stability safety factor of the dual-medium connection area.
[0048] In this way, by accurately calculating the actual anchorage length of the multi-layer connecting components as described above, we can fully consider various parameters of the original roadbed 6 and the widened area 2 of the cell filler, as well as vehicle loads and other factors, to ensure that the connecting components have sufficient anchorage length to guarantee the stability of the structure.
[0049] Specifically, in step a, the minimum anchorage length of the connecting layer 4 to be determined is calculated using a detailed formula. This formula covers many factors that affect the anchorage length, such as the density of the subgrade fill, additional load, friction coefficient, burial depth, and cell deformation, making the calculation results more accurate and reliable.
[0050] Step b calculates the overall stability safety factor of the dual-medium connection zone under specific conditions, and further evaluates the anchoring of the connection components from the perspective of overall structural stability.
[0051] Step c determines the final actual anchorage length based on the comparison between the calculated overall stability safety factor and the safety factor threshold. If the requirements are not met, the anchorage length is re-determined and recalculated until the stability requirements are met. This method effectively solves the problem of unreasonable setting of the length of connecting components, improves the safety and reliability of the widened structure in the renovation and expansion project in the area with limited land, and provides a strong guarantee for the smooth implementation of the project.
[0052] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.
Claims
1. A widening structure suitable for renovation and expansion projects in areas with limited land area, characterized in that, It includes a composite foundation, a cell-filled widening zone, and a widened road surface, which are stacked sequentially from bottom to top. The composite foundation is located outside the original foundation, and the cell-filled widening zone is located outside the original roadbed. The existing roadbed is provided with a dual-medium connection zone, which includes a connection component. The connection component includes a connection layer and a reinforcing gabion stacked from bottom to top.
2. The widening structure applicable to land-constrained area renovation and expansion projects according to claim 1, characterized in that, The connecting layer and the reinforcing gabion are in close contact.
3. The widening structure applicable to land-constrained area renovation and expansion projects according to claim 1, characterized in that, The connecting components are multi-layered, and the multi-layered connecting components are evenly arranged along the vertical direction.
4. The widening structure applicable to land-constrained area renovation and expansion projects according to claim 3, characterized in that, Along the direction from bottom to top, the length of the multi-layer connecting components gradually increases.
5. A construction method for widening structures applicable to renovation and expansion projects in areas with limited land area, characterized in that, Construction of widening structures for land-constrained area renovation and expansion projects as described in any one of claims 1 to 4.
6. The construction method for widening structures applicable to land-constrained area renovation and expansion projects according to claim 5, characterized in that, The construction method includes the following steps: Step 1: Complete the construction of the composite foundation on the side of the existing foundation; Step 2: Excavate a rectangular foundation trench on the outside of the existing roadbed, and construct the reinforcing gabions and connecting layer in sequence in the rectangular foundation trench; Step 3: Complete the construction of the cell filler widening area and the widened road surface on the existing roadbed.
7. The construction method for widening structures applicable to land-constrained area renovation and expansion projects according to claim 6, characterized in that, The following steps are included before step 2: Determine the actual anchorage length of the multi-layer connection assembly.
8. The construction method for widening structures applicable to land-constrained area renovation and expansion projects according to claim 7, characterized in that, Determining the actual anchorage length of the multi-layer connection assembly includes the following steps: Step a: In the multi-layer connection components, define the i-th layer connection component as the connection component to be determined, where i is any positive integer from 1 to n, and calculate the minimum anchorage length of the connection layer to be determined; Step b: Calculate the overall stability safety factor of the dual-medium junction area; Step c: Determine whether the overall stability safety factor of the dual-medium junction area is above the safety factor threshold; If so, the minimum anchorage length of the connection layer to be determined shall be taken as the actual anchorage length of the connection layer to be determined. If not, then redetermine the anchorage length. If the anchorage length is greater than the minimum anchorage length, recalculate the overall stability safety factor of the dual-medium connection area.
9. The construction method for widening structures applicable to land-constrained area renovation and expansion projects according to claim 8, characterized in that, In step c, the safety factor threshold is 1.
2.
10. The construction method for widening structures applicable to land-constrained area renovation and expansion projects according to claim 8, characterized in that, In step b, the overall stability safety factor of the dual-medium connection zone is calculated under the condition that the widened area of the cell packing is regarded as an integral rigid structure and the friction effect between the widened area of the cell packing and the composite foundation is not considered.