Composite reinforcing structure for splicing new and old roadbeds in soft soil area

Abstract

The utility model relates to a kind of composite reinforcing structures of new and old roadbed splicing, specifically a kind of composite reinforcing structures for new and old roadbed splicing in soft soil area, including old roadbed and new roadbed, the old roadbed one end bottom is formed inverted step shape by mechanical milling, the new roadbed one end is fixedly provided with step frame, step frame is filled with new material gradually from top to bottom in it, and step frame is located on each layer step surface and is laid with three-way geogrid, and step frame is fixedly provided with support component in the bottom of each layer three-way geogrid in it, the support component is used to prevent three-way geogrid from bending downward due to gravity;By the insertion and concrete anchoring connection of the step frame, fixed cylinder and installation cylinder embedded in old roadbed, a high-strength mechanical locking node is formed, which can effectively transfer the load of new roadbed to old roadbed, and significantly resist lateral shear force.

Description

Technical Field

[0001] This utility model relates to a composite reinforcement structure for splicing new and old roadbeds, and more particularly to a composite reinforcement structure for splicing new and old roadbeds in soft soil areas. Background Technology

[0002] With the continuous improvement and upgrading of my country's transportation infrastructure network, highway reconstruction and expansion projects in soft soil areas have become commonplace. The splicing of old and new roadbeds is one of the key technical challenges. Soft soil is characterized by high water content, high compressibility, and low shear strength, making it prone to uneven settlement and lateral slippage at the splicing points of old and new roadbeds, leading to a series of problems such as pavement cracking and structural instability.

[0003] Currently, commonly used technical measures in engineering include: excavating steps on the slopes of old roadbeds to increase the contact area; laying geogrids to improve the shear resistance of the interface; and using pile foundations for foundation reinforcement. However, these traditional methods still have significant shortcomings in practical applications. First, after the steps are excavated, the interface between the old and new fill materials remains a weak point. Relying solely on geogrids laid flat on the step surface, under the compaction of the fill material and subsequent loads, the geogrids are prone to sinking or loosening, failing to fully exert their reinforcing effect, resulting in limited interfacial bonding strength. Second, the components or measures used to connect the old and new roadbeds are often relatively simple, making it difficult to form rigid and strong connection nodes, and thus unable to effectively transfer and distribute loads. In addition, water accumulation inside the roadbed in soft soil areas is difficult to drain in a timely manner, further softening the soil and weakening the long-term stability of the structure. Utility Model Content

[0004] The main objective of this invention is to provide a composite reinforcement structure for splicing new and old roadbeds in soft soil areas, in order to solve the problems raised in related technologies.

[0005] To achieve the above objectives, according to one aspect of this utility model, a composite reinforcement structure for splicing old and new roadbeds in soft soil areas is provided, comprising an old roadbed and a new roadbed. The bottom of one end of the old roadbed is formed into an inverted step shape by mechanical milling. A step frame is fixedly installed at one end of the new roadbed. The step frame is filled with new material from top to bottom, and a three-dimensional geogrid is laid on each step surface of the step frame. Supporting components are symmetrically fixedly installed at the bottom of each three-dimensional geogrid layer in the step frame. The supporting components are used to prevent the three-dimensional geogrid from bending downward due to gravity. Several fixing cylinders for further connecting the old roadbed and the new roadbed are fixedly installed on the side wall of the step frame.

[0006] Furthermore, the new material includes a layer of crushed stone laid on the lower layer of the stepped frame, a layer of cement-modified soil laid on top of the crushed stone layer, and a layer of lime-modified soil laid on top of the cement-modified soil layer.

[0007] Furthermore, several of the aforementioned triaxial geogrids are distributed and laid on the gravel layer, the cement-modified soil layer, and the lime-modified soil layer.

[0008] Furthermore, the supporting component includes a support rod fixedly installed within the step frame, and a support plate is fixedly connected to the support rod, with the support plate located at the bottom of the triaxial geogrid.

[0009] Furthermore, the support rod is a hollow tube, and a number of filter holes are arranged in a ring array through the support rod, with the filter holes inclined downward from the outside of the support rod to its inside.

[0010] Furthermore, a connecting rod is fixedly installed on the inner wall of the stepped frame between two adjacent three-dimensional geogrids, and annular connecting buckles are fixedly installed at both ends of the connecting rod. The three-dimensional geogrids are fixedly connected to the connecting buckles on the connecting rods by connecting ropes.

[0011] Furthermore, several installation grooves are mechanically milled in the old roadbed, and an installation cylinder is fixedly installed in the installation groove. A slot is opened in the installation cylinder, and one end of the fixed cylinder is inserted into the slot. The inner diameter of the installation cylinder is larger than the outer diameter of the fixed cylinder.

[0012] Furthermore, the inner wall of the mounting cylinder is symmetrically provided with grooves at the slot insertion end, and the two ends of the grooves are provided with limiting grooves that communicate with them.

[0013] Furthermore, a limiting ring is fixedly connected to the outer wall of the fixed cylinder, and a fixing plate is symmetrically fixedly connected to the outer wall of the limiting ring. The fixing plate is inserted into the groove. A column groove is opened inside the fixed cylinder, and the fixed cylinder has several through holes communicating with the column groove in a ring array.

[0014] Furthermore, an adhesive layer is filled between the old roadbed and the step frame connection surface.

[0015] Compared with the prior art, the present invention has the following beneficial effects: 1. In this composite reinforcement structure for splicing new and old roadbeds in soft soil areas, a high-strength mechanical locking node is formed by the insertion and concrete anchoring of the stepped frame, the fixing cylinder and the installation cylinder pre-embedded in the old roadbed; this node can effectively transfer the load of the new roadbed to the old roadbed and significantly resist lateral shear force.

[0016] 2. In this composite reinforcement structure for splicing new and old roadbeds in soft soil areas, support components and connecting rods are set inside the stepped frame to provide all-round support and fixation for the three-dimensional geogrid, effectively preventing it from sinking or deforming due to stress during construction and use, and ensuring that its reinforcement performance is fully utilized; at the same time, the hollow support rods and their inclined filter holes form a built-in drainage channel, which can actively collect and drain water inside the roadbed, significantly improving the long-term stability of the soft soil roadbed. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of the composite reinforcement structure used for splicing new and old roadbeds in soft soil areas in a preferred embodiment of this utility model; Figure 2 This is a partial structural diagram of the composite reinforcement structure used for splicing new and old roadbeds in soft soil areas in a preferred embodiment of the present invention; Figure 3 This is a schematic diagram of the overall structure of the step frame in a preferred embodiment of the present invention; Figure 4 This is a plan view of the step frame in a preferred embodiment of the present invention; Figure 5 This is a cross-sectional view of the support component in a preferred embodiment of the present invention; Figure 6 This is a cross-sectional view of the mounting cylinder and the fixing cylinder in a preferred embodiment of the present invention.

[0018] Figure label: 1. Old roadbed; 2. New roadbed; 3. Stepped structure; 31. Crushed stone layer; 32. Cement-modified soil layer; 33. Lime-modified soil layer; 4. Adhesive layer; 5. Triaxial geogrid; 6. Mounting cylinder; 61. Groove; 62. Limiting groove; 7. Fixing cylinder; 71. Fixing plate; 72. Column groove; 73. Through hole; 8. Supporting components; 81. Support rod; 82. Support plate; 83. Filter holes; 9. Connecting rod. Detailed Implementation

[0019] To further illustrate the technical means and effects adopted by this utility model in order to achieve the intended utility model purpose, the following detailed description of the specific implementation methods, structure, features and effects of this utility model is provided in conjunction with the accompanying drawings and preferred embodiments.

[0020] This embodiment provides a composite reinforcement structure for splicing new and old roadbeds in soft soil areas, including an old roadbed 1 and a new roadbed 2. The bottom of one end of the old roadbed 1 is formed into an inverted step shape, which provides a good foundation shape for the new roadbed 2 and increases the contact area between the two. A step frame 3 is fixedly installed at one end of the new roadbed 2. The step frame 3 is filled with new material from top to bottom. A three-dimensional geogrid 5 is laid on each step surface of the step frame 3. Supporting components 8 are symmetrically fixedly installed at the bottom of each layer of three-dimensional geogrid 5 in the step frame 3. The supporting components 8 are used to prevent the three-dimensional geogrid 5 from bending downward due to gravity. Several fixing cylinders 7 are fixedly installed on the side wall of the step frame 3 for further connecting the old roadbed 1 and the new roadbed 2.

[0021] like Figure 2 and Figure 3 As shown, the new material includes a crushed stone layer 31 laid on the lower layer of the stepped frame 3, a cement-modified soil layer 32 laid on top of the crushed stone layer 31, and a lime-modified soil layer 33 laid on top of the cement-modified soil layer 32. Each layer of new material needs to be hydraulically compacted to improve the compaction degree. The combination of crushed stone layer 31, cement-modified soil layer 32 and lime-modified soil layer 33 can effectively improve the bearing capacity and drainage performance of the new filling material.

[0022] like Figure 2 and Figure 3 As shown, several triaxial geogrids 5 are distributed and laid on the gravel layer 31, the cement-modified soil layer 32, and the lime-modified soil layer 33. The main function of the triaxial geogrids 5 is to enhance the shear resistance of the interface and prevent slippage. In addition, the triaxial geogrids 5 not only enhance the bonding strength between the layers, but also disperse stress to a certain extent and reduce local settlement.

[0023] like Figure 4 and Figure 5 As shown, the support component 8 includes a support rod 81 fixedly installed in the step frame 3, and a support plate 82 fixedly connected to the support rod 81. The support plate 82 is located at the bottom of the triaxial geogrid 5 and is used to prevent the triaxial geogrid 5 from sinking due to gravity or pressure during construction when laying or compacting new material, thereby maintaining its position and functional effectiveness.

[0024] like Figure 5 As shown, the support rod 81 is a hollow tube, and several filter holes 83 are arranged in a ring array through the support rod 81. The filter holes 83 are arranged downward from the outside of the support rod 81 to its inside. In soft soil areas, water may accumulate in the subgrade. The water can enter the interior of the support rod 81 through the filter holes 83. The lower end of the support rod 81 is connected to a drainage pipe to remove most of the water in the subgrade and enhance stability.

[0025] like Figure 4As shown, a connecting rod 9 is fixedly installed on the inner wall of the step frame 3 between two adjacent three-dimensional geogrids 5. Annular connecting buckles are fixedly installed at both ends of the connecting rod 9. The three-dimensional geogrid 5 is fixedly connected to the connecting buckles on the connecting rod 9 by a connecting rope; this ensures the installation stability of the three-dimensional geogrid 5 and prevents it from sinking.

[0026] like Figure 2 and Figure 6 As shown, several installation slots are machined in the old roadbed 1. An installation cylinder 6 is fixedly installed in the installation slot. A slot is opened in the installation cylinder 6. One end of the fixed cylinder 7 is inserted into the slot, and the inner diameter of the installation cylinder 6 is larger than the outer diameter of the fixed cylinder 7.

[0027] like Figure 6 As shown, the inner wall of the mounting cylinder 6 is symmetrically provided with grooves 61 at the slot insertion end, and the two ends of the grooves 61 are provided with limiting grooves 62 that communicate with them.

[0028] like Figure 6 As shown, a limiting ring is fixedly connected to the outer wall of the fixed cylinder 7, and a fixing plate 71 is symmetrically fixedly connected to the outer wall of the limiting ring. A limiting protrusion is symmetrically fixedly connected to the side wall of the fixing plate 71. The fixing plate 71 is inserted into the groove 61. A column groove 72 is provided inside the fixed cylinder 7, and several through holes 73 communicating with the column groove 72 are provided in a circular array. During the splicing of the old and new roadbeds, the step frame 3 moves towards the old roadbed 1, the fixed cylinder 7 is gradually inserted into the mounting cylinder 6, and the fixing plate 71 is gradually inserted into the groove 61. The limiting protrusion is squeezed by the inner wall of the groove 61. The cylinder is compressed and contracted until it aligns with the limiting groove 62. At this point, the limiting protrusion returns to its original position and engages within the limiting groove 62, thus initially fixing the fixing cylinder 7 and the mounting cylinder 6. At this time, the limiting ring is precisely inserted into the opening end of the mounting cylinder 6, thus forming an annular cavity between the inner wall of the mounting cylinder 6 and the outer wall of the fixing cylinder 7. Concrete is then injected into the column groove 72, and the concrete fills the annular cavity through the through hole 73. After curing, the fixing cylinder 7 and the mounting cylinder 6 are fixedly connected, thereby ensuring that the step frame 3 is stably installed on one side of the old roadbed 1. The side wall of the fixing cylinder 7 is provided with a grouting hole that communicates with the column groove 72.

[0029] like Figure 1 and Figure 2 As shown, an adhesive layer 4 is filled between the old roadbed 1 and the step frame 3. The adhesive layer 4 is preferably a geopolymer slurry. This slurry has good permeability and high final strength. It can penetrate into the micropores of the old and new roadbed materials and form a high-strength stone body after solidification, thereby achieving chemical bonding between the old and new roadbed materials and further strengthening the interface bonding.

[0030] In practical use, this utility model involves excavating several installation slots within the old roadbed 1 and fixing installation cylinders 6 within these slots; constructing a step frame 3 at one end of the new roadbed 2, ensuring that the fixing cylinders 7 on its side walls can accurately align with the installation cylinders 6 in the old roadbed 1; laying a three-dimensional geogrid 5 on each step surface; and connecting the three-dimensional geogrid 5 to the connecting rod 9 by using connecting ropes through the annular connecting buckles at both ends of the connecting rod 9; filling the interior of the step frame 3 with new material layer by layer, successively laying a crushed stone layer 31, a cement-improved soil layer 32, and a lime-improved soil layer 33. After each layer of new material is laid, hydraulic compaction is required to improve the compaction degree. Then, the step frame 3 is moved to the side of the old roadbed, and one end of the fixing cylinder 7 is inserted into the slot in the installation cylinder 6. During this process, the fixing plate 71 will be gradually inserted into the groove 61, and the limiting protrusion will be squeezed by the inner wall of the groove 61 and shrink until it is aligned with the limiting groove 62 and then restored and locked in the limiting groove 62. The fixing cylinder 7 and the installation cylinder 6 are initially fixed. Concrete is injected into the column groove 72. The concrete is filled into the annular cavity between the installation cylinder 6 and the fixing cylinder 7 through the through hole 73 to achieve a firm connection between the fixing cylinder 7 and the installation cylinder 6, ensuring that the step frame 3 is stably installed on the side of the old roadbed 1, and the adhesive layer 4 is filled between the connection surface of the old roadbed 1 and the step frame 3.

[0031] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Although the present utility model has been disclosed above with reference to a preferred embodiment, it is not intended to limit the present utility model. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present utility model. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present utility model without departing from the scope of the present utility model shall still fall within the scope of the present utility model.

Claims

1. A composite reinforcement structure for splicing old and new roadbeds in soft soil areas, comprising an old roadbed (1) and a new roadbed (2), characterized in that, The bottom of one end of the old roadbed (1) is formed into an inverted step shape by mechanical milling. The bottom of the new roadbed (2) is fixedly provided with a step frame (3). The step frame (3) is filled with new material from top to bottom. The step frame (3) is provided with a three-dimensional geogrid (5) on each step surface. The step frame (3) is symmetrically provided with a support component (8) at the bottom of each three-dimensional geogrid (5). The support component (8) is used to prevent the three-dimensional geogrid (5) from bending downward due to gravity. The side wall of the step frame (3) is fixed with a number of fixing cylinders (7) for further connecting the old roadbed (1) and the new roadbed (2).

2. The composite reinforcement structure for splicing new and old roadbeds in soft soil areas according to claim 1, characterized in that, The new material includes a crushed stone layer (31) laid on the lower layer of the step frame (3), a cement-modified soil layer (32) laid on top of the crushed stone layer (31), and a lime-modified soil layer (33) laid on top of the cement-modified soil layer (32).

3. The composite reinforcement structure for splicing new and old roadbeds in soft soil areas according to claim 2, characterized in that, Several of the three-dimensional geogrids (5) are distributed and laid on the gravel layer (31), the cement-modified soil layer (32), and the lime-modified soil layer (33).

4. The composite reinforcement structure for splicing new and old roadbeds in soft soil areas according to claim 1, characterized in that, The support component (8) includes a support rod (81) fixedly installed in the step frame (3), and a support plate (82) is fixedly connected to the support rod (81). The support plate (82) is located at the bottom of the triaxial geogrid (5).

5. The composite reinforcement structure for splicing new and old roadbeds in soft soil areas according to claim 4, characterized in that, The support rod (81) is a hollow tube, and a number of filter holes (83) are opened in a ring array through the support rod (81). The filter holes (83) are inclined downward from the outside of the support rod (81) to its inside.

6. The composite reinforcement structure for splicing new and old roadbeds in soft soil areas according to claim 1, characterized in that, The inner wall of the step frame (3) is fixedly provided with a connecting rod (9) between two adjacent three-dimensional geogrids (5). The two ends of the connecting rod (9) are fixedly provided with annular connecting buckles. The three-dimensional geogrids (5) are fixedly connected to the connecting buckles on the connecting rod (9) by connecting ropes.

7. The composite reinforcement structure for splicing new and old roadbeds in soft soil areas according to claim 1, characterized in that, Several installation grooves are machined in the old roadbed (1), and an installation cylinder (6) is fixedly installed in the installation groove. A slot is opened in the installation cylinder (6), and one end of the fixed cylinder (7) is inserted into the slot. The inner diameter of the installation cylinder (6) is larger than the outer diameter of the fixed cylinder (7).

8. The composite reinforcement structure for splicing new and old roadbeds in soft soil areas according to claim 7, characterized in that, The inner wall of the mounting cylinder (6) is symmetrically provided with grooves (61) at the slot insertion end, and the two ends of the grooves (61) are provided with limiting grooves (62) that communicate with them.

9. The composite reinforcement structure for splicing new and old roadbeds in soft soil areas according to claim 8, characterized in that, The outer wall of the fixed cylinder (7) is fixedly connected to a limiting ring, and a fixing plate (71) is symmetrically fixedly connected to the outer wall of the limiting ring. The fixing plate (71) is inserted into the groove (61). A column groove (72) is opened in the fixed cylinder (7). The fixed cylinder (7) is arranged in a ring array and has several through holes (73) that communicate with the column groove (72).

10. The composite reinforcement structure for splicing new and old roadbeds in soft soil areas according to claim 1, characterized in that, An adhesive layer (4) is filled between the old roadbed (1) and the step frame (3) connection surface.

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