Excavated road recovery structure for pipeline laying of built road

Abstract

The utility model discloses an excavated road recovery structure for pipeline laying of a built road, belongs to the field of road engineering, and solves the problems that the strength of an excavated road is insufficient after backfilling, and later pipeline maintenance and excavation are difficult after repair. A transverse support structure is arranged at the bottom of an excavated groove, a pipeline foundation is arranged at the top of the transverse support structure, a pipeline is arranged on the pipeline foundation, an arch structure is arranged above the pipeline, and a flowing roadbed backfill layer is filled in a groove space above the arch structure. And an upper roadbed backfill layer, a base layer structure and a surface layer structure are sequentially filled above the flowable roadbed backfill layer from bottom to top. The arch structure is arranged on the pipeline, so that the pipeline is prevented from being damaged, the pipeline is convenient to overhaul in an operation period, and the pipeline is maintained and replaced on the basis that secondary excavation of a road is not carried out; the flowable roadbed backfill layer can obtain the roadbed with high strength and small deformation without being compacted, avoids roadbed settlement damage caused by the fact that the roadbed cannot be compacted, and can also preserve heat of the pipeline.

Description

Technical Field

[0001] The utility model belongs to the field of road engineering, and in particular relates to a road restoration structure for laying excavated roads for built roads. Background Art

[0002] Unlike highways, various pipeline facilities are laid under urban roads. With the continuous development of cities, the construction specifications and operating conditions of some pipelines can no longer meet the use requirements. An important task of urban road reconstruction and upgrading is to update and renovate the existing pipeline facilities. Due to the complexity of the existing pipelines on urban roads, it is difficult to implement methods such as pipe jacking and directional drilling, which can easily cause damage to existing pipelines. Currently, pipeline reconstruction and updating basically adopt the construction method of trench excavation. Affected by factors such as urban road space and closed traffic, the excavation width of pipeline reconstruction trenches is often limited, and the narrow trench backfill cannot be rolled by large-scale mechanical operations, resulting in the overall stiffness, strength and compaction of the road restored by pipeline reconstruction being inferior to the original roadbed structure. The road often produces uneven settlement during operation, affecting road traffic safety and service life.

[0003] For road damage caused by pipeline excavation and restoration, secondary excavation repair is mainly used, such as backfilling with higher-strength materials such as cement concrete and grouting for secondary reinforcement of the trench, but none of them can completely solve the road settlement and cracking problems, and it is easy to cause difficulties in subsequent pipeline maintenance and excavation. For problems such as settlement and cracking after pipeline excavation on built roads, the fundamental solution to the problems lies in the trench restoration structure after pipeline excavation. How to adopt a feasible, effective, easy-to-construct, and easy-to-maintain pipeline excavation road restoration structure to avoid settlement and cracking of roads after construction, while facilitating pipeline maintenance and avoiding secondary pipeline excavation, is of great significance to urban pipeline network reconstruction and road maintenance. Utility Model Content

[0004] The utility model aims to provide a road excavation restoration structure for laying pipelines on built roads, so as to solve the problem that the excavated road has insufficient strength after backfilling, which causes difficulty in subsequent pipeline maintenance and excavation after repair.

[0005] The technical solution of the utility model is: a road excavation restoration structure for laying pipelines on an existing road, a cross bracing structure is provided at the bottom of the excavated trench, a pipeline foundation is provided on the top of the cross bracing structure, the pipeline is arranged on the pipeline foundation, an arch structure is provided above the pipeline, a fluid roadbed backfill layer is filled in the trench space above the arch structure, and an upper roadbed backfill layer, a base layer structure and a surface layer structure are filled in sequence from bottom to top above the fluid roadbed backfill layer.

[0006] As a further improvement of the utility model, the upper roadbed backfill layer extends out of both sides of the groove.

[0007] As a further improvement of the utility model, the base layer structure and the surface layer structure extend out of both sides of the upper roadbed backfill layer.

[0008] As a further improvement of the utility model, arch foot side wall structures are provided on both sides of the cross bracing structure, and the lower end of the arch structure is connected to the arch foot side wall structure.

[0009] As a further improvement of the utility model, the arch structure and the arch foot side wall structure are fixedly connected by shear nails.

[0010] As a further improvement of the utility model, a retaining wall is provided between the arch foot side wall structure and the side slope of the groove.

[0011] As a further improvement of the utility model, a honeycomb geocell is provided between the upper roadbed backfill layer and the fluid roadbed backfill layer.

[0012] As a further improvement of the utility model, a steel-plastic grid is provided at the overlap between the upper roadbed backfill layer and the base structure.

[0013] As a further improvement of the utility model, the flowable roadbed backfill layer is backfilled with air bubble mixed lightweight soil.

[0014] The beneficial effects of the utility model are:

[0015] 1. The utility model structure does not require large-scale mechanical construction, is suitable for the restoration of pipe trenches with small excavation working surfaces, has a small closure range for urban roads, and has little impact on traffic pressure.

[0016] 2. The utility model arranges an arch structure on the pipeline, which converts the vertical road structure layer load and traffic load into a horizontal force, thereby ensuring that the pipeline is not affected by load during construction and operation, avoiding damage to the pipeline, facilitating maintenance during operation, and repairing and replacing the pipeline without secondary excavation of the road.

[0017] 3. The utility model adopts air bubble mixed lightweight soil to backfill the fluid roadbed backfill layer on the arch structure, which does not need to be compacted to obtain a roadbed with high strength and small deformation. The utility model realizes the overall strength of the pipeline roadbed and eliminates settlement deformation through its own self-fluidity and self-hardening properties, thus avoiding the roadbed settlement disease caused by the inability to compact the roadbed. While improving the overall strength of the pipeline roadbed, it can also insulate the pipeline and prevent the pipeline from being damaged by frost heave.

[0018] 4. The utility model realizes the overall coordinated deformation of the road by setting honeycomb geocells in the backfill layer of the upper roadbed and steel-plastic grids in the base structure, improves the overall deformation capacity of the pipeline to restore the road structure, and eliminates settlement and crack diseases caused by different stiffness and uneven deformation of the new and old road surfaces. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of the utility model;

[0020] Figure 2 It is a structural schematic diagram of the middle arch structure of the utility model.

[0021] In the figure: 1-arch structure; 2-arch foot side wall structure; 3-cross bracing structure; 4-pipeline foundation; 5-pipeline; 6-retaining wall; 7-flowable roadbed backfill layer; 8-groove; 9-honeycomb geocell; 10-upper roadbed backfill layer; 11-steel-plastic grid; 12-base structure; 13-surface structure; 14-precast concrete arch unit; 15-shear studs. DETAILED DESCRIPTION

[0022] The utility model is described in detail below with reference to the accompanying drawings.

[0023] like Figure 1 , Figure 2 As shown, a road excavation restoration structure for laying pipelines on an existing road is provided, a cross bracing structure 3 is provided at the bottom of the excavated trench 8, a pipeline foundation 4 is provided on the top of the cross bracing structure 3, a pipeline 5 is arranged on the pipeline foundation 4, an arch structure 1 is provided above the pipeline 5, and a fluid roadbed backfill layer 7 is filled in the space of the trench 8 above the arch structure 1, and an upper roadbed backfill layer 10, a base structure 12 and a surface structure 13 are filled in sequence from bottom to top above the fluid roadbed backfill layer 7.

[0024] The upper roadbed backfill layer 10 extends out of both sides of the groove 8 .

[0025] The base structure 12 and the surface structure 13 extend out of both sides of the upper roadbed backfill layer 10 .

[0026] Arch foot side wall structures 2 are arranged on both sides of the cross bracing structure 3, and the lower end of the arch structure 1 is connected to the arch foot side wall structure 2. The arch structure 1 and the arch foot side wall structure 2 are fixedly connected by shear nails 15.

[0027] A retaining wall 6 is provided between the arch foot side wall structure 2 and the side slope of the groove 8 .

[0028] A honeycomb geocell 9 is provided between the upper roadbed backfill layer 10 and the fluid roadbed backfill layer 7 .

[0029] A steel-plastic grid 11 is provided at the overlap between the upper roadbed backfill layer 10 and the base structure 12 .

[0030] The fluid roadbed backfill layer 7 is backfilled with air bubble mixed lightweight soil.

[0031] The arch structure 1 is assembled in sequence from a plurality of precast concrete arch units 14, and the joints at the splicing positions are filled with asphalt hemp. The length of the precast concrete arch unit 14 is 1 to 2 m, and the thickness is 0.1 to 0.2 m, which is determined according to the span of the arch structure 1. A larger value is taken when the span is large, and a smaller value is taken when the span is small. The arch foot is enlarged and a rectangular structure is adopted; the rise S and clear span L of the precast concrete arch unit 14 are determined according to the pipe diameter D of the pipeline 5, and the rise S=0.25m+2 / 3D, and the clear span L=2S.

[0032] The arch foot side wall structure 2 is a groove-shaped concrete structure, which is arranged parallel to the pipeline 5 and has a width of 0.5m. The wall height H of the arch foot side wall structure 2 is determined according to the pipe diameter D of the pipeline 5, and the height H=0.5D+0.25m.

[0033] The cross bracing structure 3 is cast with cement concrete and has a thickness of 15 cm. Steel bars are arranged inside and anchored in the arch foot side wall structures 2 on both sides. A pipe foundation 4 is arranged on the upper part of the cross bracing structure 3. The pipe foundation 4 is made of arc-shaped natural gravel. The pipe foundation 4 and the pipe 5 are in a 120° fan-shaped structure.

[0034] The retaining wall 6 is cast with C15 cement concrete, the back slope is consistent with the side slope of the groove 8, the face slope is 1:0.25, and the top of the retaining wall 6 is flush with the top of the arch structure 1.

[0035] Embodiment 1,

[0036] Taking the renovation of the existing road water supply pipeline as an example, the diameter of the water supply pipeline 5 is DN400mm, and the corresponding arch structure rise S=0.25+2 / 3×0.4=0.52m, and the arch structure span L=2×0.52=1m. The trench 8 is excavated with the trench bottom width of 1m as the boundary. When the foundation soil is clay soil, the slope of trench 8 is 1:0.25~1:0.33, and when the foundation soil is gravel soil, the slope of trench 8 is 1:0.45~1:0.75.

[0037] A cross brace structure 3 is set at the bottom of the groove 8. The cross brace structure 3 is 15 cm thick and is cast in place with C30 cement concrete. Inside, φ20 tie rods are set every 20 cm to anchor in the arch foot side wall structure 2. On the one hand, the cross brace structure 3 connects the arch foot side wall structure 2 horizontally to balance the horizontal force generated at the arch foot and prevent the arch foot from horizontal displacement; on the other hand, it serves as the bearing layer of the pipeline foundation 4 to improve the bearing capacity of the pipeline foundation and prevent the vertical deformation of the pipeline 5 due to insufficient bearing capacity of the foundation. The pipeline foundation 4 is set on the top of the cross brace structure 3. The pipeline foundation 4 adopts a 120° fan-shaped medium-coarse sand foundation, and the DN400 water supply pipeline 5 is installed on the arc-shaped medium-coarse sand foundation.

[0038] The arch foot side wall structure 2 is cast in situ with C30 cement concrete, adopts a trough structure, with a wall thickness of 0.5m, a wall thickness of 30cm at the trough part, and a height of H=0.5×0.4+0.25=0.45m. The arch foot of the arch structure 1 is installed in the groove of the arch foot side wall structure 2, and the arch foot of the arch structure 1 is anchored and connected to the arch foot side wall structure 2 through shear nails 15 of φ16~φ22, and the spacing between the shear nails 15 is 25cm.

[0039] The retaining wall 6 foot is cast as an integrated structure with the arch foot side wall structure 2. The retaining wall 6 is constructed after the arch foot side wall structure 2 is completed. On the one hand, it stabilizes the slope of the excavated trench 8 to prevent the slope from sliding during the construction and installation of the pipeline 5; on the other hand, it offsets the soil side pressure generated by the slope of the trench 8 and the side pressure generated by the vehicle load during operation, preventing the arch structure 1 from being displaced by horizontal force and affecting the pipeline.

[0040] The fluid roadbed backfill layer 7 is poured in layers. The first layer is poured until it is flush with the top surface of the arch structure 1 and the top surface of the retaining wall 6. In this range, bubble mixed lightweight soil with bulk density grade W3~W5 and strength grade CF0.4~CF0.6 is used, with a bulk density of 400Kg / m3~500Kg / m3 and a compressive strength of 0.4MPa~0.6MPa. The fluid roadbed backfill layer 7 above the top surface of the arch structure 1 uses bubble mixed lightweight soil with bulk density grade W6~W7 and strength grade CF1~CF1.5, with a bulk density of 600Kg / m3~700Kg / m3 and a compressive strength of 1.0MPa~1.5MPa. The pouring height of each layer is 0.3~0.5m, and the pouring is stopped when it is poured to 30cm below the top surface of the roadbed. After pouring, plastic film or non-woven fabric is used to cover the surface for moisturizing maintenance, and the maintenance age is not less than 7d.

[0041] When the strength and age of the fluid roadbed backfill layer 7 meet the requirements, the upper roadbed backfill layer 10 is backfilled. The upper roadbed backfill layer 10 overlaps the fluid roadbed backfill layer 7 in a step-like manner, and the width of the outward-expanded step is 0.5m. A honeycomb geocell 9 is arranged between the upper roadbed backfill layer 10 and the fluid roadbed backfill layer 7, and is backfilled with crushed stone with a thickness of 30cm. The nominal maximum particle size of the crushed stone of the upper roadbed backfill layer 10 should not be greater than 31.5mm. The honeycomb geocell 9 is made of HDPE material with a thickness of 2mm, the honeycomb mesh size is 10cm×10cm, and the cell height is 15cm. After the honeycomb geocell 9 is laid and fixed on the fluid roadbed backfill layer 7, it is backfilled with crushed stone. After the crushed stone is filled, a high-energy roller of more than 25T is used to compact it, and the compaction of the upper roadbed backfill layer 10 is ≥95%.

[0042] After the compaction degree of the upper roadbed backfill layer 10 reaches the requirements, the base structure 12 and the surface structure 13 are laid. The newly built base structure 12 and the upper roadbed backfill layer 10 are overlapped in a step-shaped manner, with an outward step width of 0.3m. A steel-plastic grid 11 is set at the overlap position. The steel-plastic grid 11 has a longitudinal and transverse ultimate tensile strength of 100KN / m and an elongation of 3% under the longitudinal and transverse ultimate tensile strength. The base structure 12 uses cement-stabilized crushed stone or cement-stabilized gravel. The thickness of the base structure 12 is determined according to the traffic volume of the road. A single-layer or double-layer water-stabilized base layer of 15~20cm can be used. The surface structure 13 uses asphalt concrete pavement. The upper layer uses 4~5cm thick fine-grained asphalt concrete AC-13 or medium-grained rubber asphalt concrete AC-16, and the lower layer is 6~7cm thick medium-grained asphalt concrete AC-20 or coarse-grained rubber asphalt concrete AC-25.

[0043] The utility model avoids road settlement, cracking and other defects after the trench excavation and restoration of an existing road. The utility model is not limited to the above-mentioned implementation mode, and can also be used to repair road settlement and other defects within the trench restoration range, or when the construction conditions of a new road are limited and the trench excavation is narrow and cannot be compacted, the same effect can be achieved.

Claims

1. A road restoration structure for laying pipelines on an existing road, characterized by: A cross bracing structure (3) is provided at the bottom of the excavated trench (8), a pipeline foundation (4) is provided on the top of the cross bracing structure (3), a pipeline (5) is arranged on the pipeline foundation (4), an arch structure (1) is provided above the pipeline (5), a fluid roadbed backfill layer (7) is filled in the trench (8) space above the arch structure (1), and an upper roadbed backfill layer (10), a base structure (12) and a surface structure (13) are filled in order from bottom to top above the fluid roadbed backfill layer (7).

2. The structure for restoring an excavated road for laying pipelines on an existing road according to claim 1, characterized in that: The upper roadbed backfill layer (10) extends beyond both sides of the groove (8).

3. The structure for restoring an excavated road for laying pipelines on an existing road according to claim 2, characterized in that: The base layer structure (12) and the surface layer structure (13) extend beyond both sides of the upper roadbed backfill layer (10).

4. A road excavation restoration structure for laying pipelines on an existing road according to any one of claims 1 to 3, characterized in that: Arch foot side wall structures (2) are provided on both sides of the cross bracing structure (3), and the lower end of the arch structure (1) is connected to the arch foot side wall structure (2).

5. The structure for restoring an excavated road for laying pipelines on an existing road according to claim 4, characterized in that: The arch structure (1) and the arch foot side wall structure (2) are fixedly connected via shear nails (15).

6. The structure for restoring an excavated road for laying pipelines on an existing road according to claim 5, characterized in that: A retaining wall (6) is provided between the arch foot side wall structure (2) and the side slope of the groove (8).

7. The structure for restoring an excavated road for laying pipelines on an existing road according to claim 6, characterized in that: A honeycomb geocell (9) is provided between the upper roadbed backfill layer (10) and the fluid roadbed backfill layer (7).

8. The structure for restoring an excavated road for laying pipelines on an existing road according to claim 7, characterized in that: A steel-plastic grid (11) is provided at the overlap between the upper roadbed backfill layer (10) and the base structure (12).

9. The structure for restoring an excavated road for laying pipelines on an existing road according to claim 8, characterized in that: The fluid roadbed backfill layer (7) is backfilled with air bubble mixed lightweight soil.

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