Backfill structure for subgrade in narrow areas

Abstract

This utility model relates to a backfill structure for roadbeds in narrow areas, comprising a supporting wall, a first fill layer, and a second fill layer; the first fill layer forms a step on the side near the supporting wall, and the distance from the step to the supporting wall decreases downward; one side of the second fill layer abuts against the supporting wall, and the other side of the second fill layer is erected on the step of the first fill layer; a pit is first dug to form a stepped first fill layer and compacted, and then the second fill layer is poured in layers. During the layered pouring process, one can stand on the step to compact the already poured parts below, ensuring that each layer in the second fill layer can be effectively compacted, greatly reducing weak areas in the backfill and improving the service life of the road.

Description

Technical Field

[0001] This utility model relates to the field of road construction technology, and in particular to a backfill structure for roadbeds in narrow areas. Background Technology

[0002] In the process of road construction and operation management, backfilling projects in narrow areas are often involved, such as trench backfilling, pipeline inspection well treatment, roadbed repair for road excavation projects, foundation backfilling, cut-fill junction treatment, roadbed backfilling above shallow buried structures, and backfilling of three backs (bridge abutment back, culvert side back and retaining wall back).

[0003] For backfilling projects in the aforementioned narrow areas, the presence of adjacent structures and limited working space make it difficult to effectively compact with large compaction machinery. This easily leads to weak areas in the backfill, resulting in significant post-construction settlement and differential settlement. Consequently, the pavement structural layer prematurely develops longitudinal cracks, potholes, and subsidence. These types of damage are irreversible, severely weakening pavement performance and driving safety, and significantly shortening the road's service life. Utility Model Content

[0004] In view of this, it is necessary to provide a backfill structure for roadbeds in narrow areas to solve the problem that in backfilling projects in narrow areas, due to the presence of nearby structures and limited working space, it is difficult to use large compaction machinery for effective rolling, which easily leads to weak backfill areas and short road service life.

[0005] This utility model provides a backfill structure for roadbeds in narrow areas, including a supporting wall, a first filling layer and a second filling layer; the first filling layer forms a step on the side near the supporting wall, and the distance from the step to the supporting wall decreases in the downward direction; one side of the second filling layer abuts against the supporting wall, and the other side of the second filling layer is erected on the step of the first filling layer.

[0006] Furthermore, the side of the supporting wall closest to the first filling layer is a slope, and it slopes downward in the direction pointing towards the first filling layer.

[0007] Furthermore, the top surfaces of the steps of the first filling layer are all sloping surfaces, and all of them slope downwards in the direction pointing towards the supporting wall.

[0008] Furthermore, the first filling layer is a soil layer.

[0009] Furthermore, the second filling layer is a fluid fly ash slurry layer.

[0010] Furthermore, it also includes a cushion layer disposed at the bottom of the second filling layer and abutting the bottom of the first filling layer.

[0011] Furthermore, the cushion layer includes a reverse-filter geotextile and gravel, wherein the reverse-filter geotextile wraps the gravel and forms a bag-like structure.

[0012] Furthermore, it also includes a road fill layer disposed on top of the first fill layer.

[0013] Furthermore, the road fill layer includes a ramp and a pavement asphalt layer, and the second fill layer, the ramp and the pavement asphalt layer are stacked sequentially in a vertically upward direction.

[0014] Furthermore, it also includes a top slab, and there are two supporting walls. The tops of the two supporting walls are fixedly connected to the two sides of the top slab. The two supporting walls and the top slab form a culvert. A second filling layer and a first filling layer are provided on both sides of the culvert.

[0015] Compared with existing technologies, the first step involves digging a pit to form a stepped first filling layer and compacting it, followed by pouring the second filling layer in layers. During the layered pouring process, one can stand on the steps to compact the already poured parts below, ensuring that each layer in the second filling layer can be effectively compacted, greatly reducing weak areas in the backfill and improving the service life of the road. Attached Figure Description

[0016] Figure 1 A schematic diagram of the overall structure of the backfill structure for roadbed in narrow areas provided in this embodiment of the utility model;

[0017] Figure 2 This is a schematic diagram of the backfill structure applied to a slab culvert. Detailed Implementation

[0018] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of this application 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.

[0019] like Figure 1 As shown, the present invention provides a backfill structure for roadbeds in narrow areas, including a support wall 100, a first fill layer 200, and a second fill layer 300; a step 210 is formed on the side of the first fill layer 200 near the support wall 100, and the distance from the step 210 to the support wall 100 decreases in the downward direction; one side of the second fill layer 300 abuts against the support wall 100, and the other side of the second fill layer 300 is erected on the step 210 of the first fill layer 200.

[0020] During implementation, first, a pit is dug to form a first filling layer 200 in the shape of a step 210 and compacted. Then, the second filling layer 300 is poured in layers. During the process of pouring in layers, one can stand on the step 210 to compact the already poured parts below, ensuring that each layer in the second filling layer 300 can be effectively compacted, greatly reducing weak areas in the backfill and improving the service life of the road.

[0021] In this implementation plan, the support wall 100 is a support structure on one side of the backfill area.

[0022] To facilitate the compaction of the fill material in the second fill layer 300, in one embodiment, the side of the supporting wall 100 closest to the first fill layer 200 is sloped and inclined downwards in the direction pointing towards the first fill layer 200. During the pouring process of the second fill layer 300, under its own weight and the guiding effect of the supporting wall 100, the upper fill material exerts a large force on the lower fill material, thereby ensuring that the fill material in the second fill layer 300 is compacted layer by layer.

[0023] In this embodiment, the first filling layer 200 is a soil layer, which is formed by excavation and forms a cavity between it and the supporting wall 100 for filling the second filling layer 300.

[0024] In one embodiment, multiple top surfaces of the steps 210 of the first filling layer 200 are sloped and all slope downward in the direction pointing toward the supporting wall 100.

[0025] In this embodiment, the second filling layer 300 is formed by casting.

[0026] In one embodiment, the second fill layer 300 is a fluid fly ash slurry layer. Due to its excellent flow and self-compacting properties, fluid fly ash eliminates the need for traditional compaction processes, reducing the amount of roadbed excavation and backfilling work by 50%-60%, and correspondingly reducing project costs by 40%-50%.

[0027] Due to its high moisture content, fluid fly ash requires a water filtration mechanism to solidify and form a hardened body with stable structural strength only after the slurry has completely exuded water. To ensure construction quality, a complete drainage system is necessary. In one embodiment, a cushion layer 400 is included, located at the bottom of the second fill layer 300 and connected to the bottom of the first fill layer 200. The cushion layer 400 comprises a filter geotextile and gravel, with the filter geotextile wrapping the gravel to form a bag-like structure.

[0028] This 400-layer cushion layer effectively drains grout leakage while preventing cement-fly ash grout from seeping into the gravel pores through its wrapping layer, allowing only water to drain through the cushion layer 400. PVC drainage pipes can be pre-embedded simultaneously, with each pipe's end near the pouring side wrapped with reverse-filter geotextile, forming a double protection mechanism to prevent grout from clogging the drainage channels.

[0029] In one embodiment, a road fill layer 500 is further provided on top of the first fill layer 200.

[0030] The road fill layer 500 includes a slab 510 and an asphalt pavement layer 520, and the second fill layer 300, the slab 510 and the asphalt pavement layer 520 are stacked sequentially in a vertically upward direction.

[0031] like Figure 2 As shown in the figure, this embodiment also includes a top plate 110, two support walls 100, the tops of the two support walls 100 are fixedly connected to the two sides of the top plate 110, the two support walls 100 and the top plate 110 form a cover culvert M, and a second filling layer 300 and a first filling layer 200 are provided on both sides of the cover culvert M.

[0032] Compared with existing technologies: First, a pit is dug to form a first filling layer 200 in the shape of a step 210 and compacted. Then, the second filling layer 300 is poured in layers. During the layered pouring process, one can stand on the step 210 to compact the already poured part below, ensuring that each layer in the second filling layer 300 can be effectively compacted, greatly reducing weak areas in the backfill and improving the service life of the road.

[0033] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present utility model should be included within the protection scope of the present utility model.

Claims

1. A backfill structure for roadbeds in narrow areas, characterized in that, include: Supporting wall; The first filling layer has a stepped structure on the side closest to the supporting wall, and the distance from the stepped structure to the supporting wall decreases in the downward direction; The second filling layer abuts against the supporting wall on one side, and the other side of the second filling layer is erected on the steps of the first filling layer.

2. The backfill structure for roadbeds in narrow areas according to claim 1, characterized in that, The side of the supporting wall closest to the first filling layer is sloping and tilts downward in the direction pointing towards the first filling layer.

3. The backfill structure for roadbeds in narrow areas according to claim 1, characterized in that, The top surfaces of the steps of the first filling layer are all sloping surfaces, and all of them slope downward in the direction pointing towards the supporting wall.

4. The backfill structure for roadbeds in narrow areas according to claim 1, characterized in that, The first filling layer is a soil layer.

5. The backfill structure for roadbeds in narrow areas according to claim 1, characterized in that, The second filling layer is a fluid fly ash slurry layer.

6. The backfill structure for roadbeds in narrow areas according to claim 1, characterized in that, It also includes a cushion layer disposed at the bottom of the second filling layer and abutting the bottom of the first filling layer.

7. The backfill structure for roadbeds in narrow areas according to claim 6, characterized in that, The cushion layer includes a filter geotextile and gravel, wherein the filter geotextile wraps the gravel and forms a bag-like structure.

8. The backfill structure for roadbeds in narrow areas according to claim 1, characterized in that, It also includes a road fill layer disposed on top of the first fill layer.

9. The backfill structure for roadbeds in narrow areas according to claim 8, characterized in that, The road fill layer includes a ramp and an asphalt paving layer, and the second fill layer, the ramp and the asphalt paving layer are stacked sequentially in a vertically upward direction.

10. The backfill structure for roadbeds in narrow areas according to claim 1, characterized in that, It also includes a top slab, and there are two supporting walls. The tops of the two supporting walls are fixedly connected to the two sides of the top slab. The two supporting walls and the top slab form a culvert. A second filling layer and a first filling layer are provided on both sides of the culvert.

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