Bridge abutment back roadbed structure

Abstract

The utility model provides a bridge abutment back roadbed structure which comprises a first graded broken stone hardcore, a first earthwork standard room, a first bidirectional geogrid, a foam light soil layer group, a second bidirectional geogrid, a second graded broken stone hardcore, a second earthwork standard room and a concrete layer group, the first graded broken stone hardcore, the first two-way geogrid, the foam light soil layer group, the second two-way geogrid, the second graded broken stone hardcore and the concrete layer group are sequentially arranged from bottom to top, the first geocell is arranged in the first graded broken stone hardcore, and the second geocell is arranged in the second graded broken stone hardcore. And the second geocell is arranged in the second graded broken stone hardcore. According to the abutment back roadbed structure, the settlement characteristic of the roadbed is improved, the overall stability and the bearing capacity of the roadbed are improved, and the dead weight of the roadbed can be effectively reduced, so that post-construction settlement at the bridge joint is reduced, the stability and the bearing capacity of the roadbed are improved, and the safety and the comfort of driving are ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of roads and bridges, in particular to a bridge abutment back roadbed structure. Background Art

[0002] Bridge jumping is a phenomenon caused by uneven settlement of the transition section of the bridge. The settlement difference will cause the vehicle to bump when driving at the junction of the bridge and the road, affecting driving safety and comfort. This settlement difference may also cause structural damage, increase maintenance costs and reduce the service life of the bridge. The traditional way to deal with bridge jumping is to install a transition beam or transition plate between the bridge and the roadbed to reduce the height difference. However, the defect of this method is that the roadbed structure is not treated. The back of the abutment roadbed will undergo a large settlement and lateral displacement over time, resulting in a void under the transition beam or transition plate and thus cracking and damage.

[0003] Therefore, it is necessary to provide a bridge abutment back roadbed structure which can improve the settlement characteristics of the roadbed and enhance the overall stability and bearing capacity of the roadbed. Utility Model Content

[0004] The utility model aims to provide a bridge abutment back roadbed structure which can improve the settlement characteristics of the roadbed and enhance the overall stability and bearing capacity of the roadbed.

[0005] To achieve the above-mentioned purpose, the utility model provides a bridge abutment back roadbed structure, including a first graded gravel cushion layer, a first geocell, a first bidirectional geogrid, a foam lightweight soil layer group, a second bidirectional geogrid, a second graded gravel cushion layer, a second geocell and a concrete layer group, wherein the first graded gravel cushion layer, the first bidirectional geogrid, the foam lightweight soil layer group, the second bidirectional geogrid, the second graded gravel cushion layer and the concrete layer group are arranged in sequence from bottom to top, the first geocell is arranged in the first graded gravel cushion layer, and the second geocell is arranged in the second graded gravel cushion layer.

[0006] Preferably, one end of the first bidirectional geogrid is fixedly connected to the roadbed soil, and the other end of the first bidirectional geogrid is fixedly connected to the abutment back fixing piece.

[0007] Preferably, the first bidirectional geogrid is fixedly connected to the roadbed soil and the abutment back fixings respectively through plastic ground nails.

[0008] Preferably, one end of the second bidirectional geogrid is fixedly connected to the roadbed soil, and the other end of the second bidirectional geogrid is fixedly connected to the abutment back fixing piece.

[0009] Preferably, the second bidirectional geogrid is fixedly connected to the roadbed soil and the abutment back fixings respectively through plastic ground nails.

[0010] Preferably, the foam lightweight soil layer group includes a foam lightweight soil layer and a third bidirectional geogrid, and several layers of the foam lightweight soil layers are arranged in sequence from bottom to top. The bottom layer of the foam lightweight soil layer is arranged above the first bidirectional geogrid, and the third bidirectional geogrid is arranged between the upper and lower adjacent foam lightweight soil layers, and the top layer of the foam lightweight soil layer is located below the second bidirectional geogrid.

[0011] Preferably, one end of the third bidirectional geogrid is fixedly connected to the roadbed soil, and the other end of the third bidirectional geogrid is fixedly connected to the abutment back fixing piece.

[0012] Preferably, the third bidirectional geogrid is fixedly connected to the roadbed soil and the abutment back fixings respectively through plastic ground nails.

[0013] Preferably, the concrete layer group includes a plain concrete stabilization layer and a reinforced concrete slab, the plain concrete stabilization layer is arranged above the second graded crushed stone cushion layer, and the reinforced concrete slab is arranged above the plain concrete stabilization layer.

[0014] Preferably, a composite foundation composed of flexible piles and soil is provided below the first graded gravel cushion layer.

[0015] Compared with the prior art, the abutment back roadbed structure of the utility model is effectively reinforced by arranging a first bidirectional geogrid, a second bidirectional geogrid, a first geocell and a second geocell, wherein the first bidirectional geogrid and the second bidirectional geogrid can control the shear strain in the roadbed soil, the first geocell and the second geocell can homogenize the stress distribution, and under the lateral limit of the three-dimensional honeycomb of the first geocell and the second geocell, the bending strength of the first graded crushed stone cushion layer and the second graded crushed stone cushion layer can be increased and the settlement displacement and lateral displacement of the roadbed can be limited, thereby improving the settlement characteristics of the roadbed, and improving the overall stability and bearing capacity of the roadbed. At the same time, by introducing a foam lightweight soil layer group as filler, the dead weight of the roadbed can be effectively reduced, thereby reducing the post-construction settlement at the bridge junction, improving the stability and bearing capacity of the roadbed, and ensuring driving safety and comfort. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural diagram of the abutment back roadbed structure of the utility model.

[0017] Figure 2 yes Figure 1 Enlarged view of point A in the middle.

[0018] Figure 3 yes Figure 1 Enlarged view of point B in the middle. DETAILED DESCRIPTION

[0019] In order to explain the technical content and structural features of the present invention in detail, further description will be given below in combination with the embodiments and the accompanying drawings.

[0020] See also Figure 1 The abutment back roadbed structure 100 of the utility model includes a first graded gravel cushion layer 1, a first geocell 2, a first bidirectional geogrid 3, a foam lightweight soil layer group 4, a second bidirectional geogrid 5, a second graded gravel cushion layer 6, a second geocell 7 and a concrete layer group 8. The first graded gravel cushion layer 1, the first bidirectional geogrid 3, the foam lightweight soil layer group 4, the second bidirectional geogrid 5, the second graded gravel cushion layer 6 and the concrete layer group 8 are arranged in sequence from bottom to top, the first geocell 2 is arranged in the first graded gravel cushion layer 1, and the second geocell 7 is arranged in the second graded gravel cushion layer 6. Among them, the graded crushed stone selected for the first graded crushed stone cushion layer 1 and the second graded crushed stone cushion layer 6 should be hard in texture and have uniform particles, and the particle size range can be controlled within 4.75mm to 37.5mm, but not limited to this; the first geocell 2 and the second geocell 7 can be made of high-strength, wear-resistant high-density polyethylene (HDPE) material, and the geocell thickness is 10 to 20mm, but not limited to this.

[0021] See also Figure 1 and Figure 2 In this embodiment, one end of the first bidirectional geogrid 3 is fixedly connected to the roadbed soil 91, and the other end of the first bidirectional geogrid 3 is fixedly connected to the abutment back fixing member 92. Specifically, the first bidirectional geogrid 3 is fixedly connected to the roadbed soil 91 and the abutment back fixing member 92 through plastic ground nails 93, but the present invention is not limited thereto. The abutment back fixing member 92 can be screwed to the abutment back through drilling holes, but the present invention is not limited thereto.

[0022] See also Figure 1 and Figure 3 In this embodiment, one end of the second bidirectional geogrid 5 is fixedly connected to the roadbed soil 91, and the other end of the second bidirectional geogrid 5 is fixedly connected to the abutment back fixing member 92. Specifically, the second bidirectional geogrid 5 is fixedly connected to the roadbed soil 91 and the abutment back fixing member 92 through plastic ground nails 93, but the present invention is not limited thereto. The abutment back fixing member 92 can be screwed to the abutment back through drilling holes, but the present invention is not limited thereto.

[0023] See also Figure 1 and Figure 2, the foam lightweight soil layer group 4 includes a foam lightweight soil layer 41 and a third bidirectional geogrid 42. Several layers of foam lightweight soil layers 41 are arranged in sequence from bottom to top. The bottom foam lightweight soil layer 41 is arranged above the first bidirectional geogrid 3. The third bidirectional geogrid 42 is arranged between the upper and lower adjacent foam lightweight soil layers 41. The top foam lightweight soil layer 41 is located below the second bidirectional geogrid 5. In this embodiment, the number of foam lightweight soil layers 41 is three, and the number of third bidirectional geogrids 42 is two, but it is not limited to this. For example, in other implementations, the number of foam lightweight soil layers 41 can also be four, and the number of third bidirectional geogrids 42 is three. Among them, the thickness of the foam lightweight soil layer 41 is about 1 / 5 of the total thickness of the roadbed structure. The foam lightweight soil layer 41 is mixed with cement, soil, foaming agent, etc., and its density and strength can be adjusted according to the needs of the project, but it is not limited to this.

[0024] See also Figure 2 In this embodiment, one end of the third bidirectional geogrid 42 is fixedly connected to the roadbed soil 91, and the other end of the third bidirectional geogrid 42 is fixedly connected to the abutment back fixing member 92. Specifically, the third bidirectional geogrid 42 is fixedly connected to the roadbed soil 91 and the abutment back fixing member 92 through plastic ground nails 93, but the present invention is not limited thereto. The abutment back fixing member 92 can be screwed to the abutment back through drilling holes, but the present invention is not limited thereto.

[0025] See also Figure 1 In this embodiment, the concrete layer group 8 includes a plain concrete stabilization layer 81 and a reinforced concrete slab 82. The plain concrete stabilization layer 81 is arranged above the second graded crushed stone cushion layer 6, and the reinforced concrete slab 82 is arranged above the plain concrete stabilization layer 81. However, the structure of the concrete layer group 8 is not limited thereto. Furthermore, a road surface material 95 can be laid above the reinforced concrete slab 82.

[0026] See also Figure 1 In this embodiment, a composite foundation 94 composed of flexible piles 941 and soil is provided below the first graded gravel cushion layer 1 .

[0027] Combination Figures 1 to 3 The specific construction steps of the abutment back roadbed structure 100 of the utility model are as follows:

[0028] S1, constructing flexible piles 941 in the roadbed construction area behind the abutment, and forming a composite foundation 94 with high bearing capacity through the combination of the flexible piles 941 and the soil.

[0029] S2, after the composite foundation 94 in the construction area of ​​the abutment back roadbed settles and stabilizes, the base is leveled and rolled to ensure that there are no hard protrusions such as gravel and boulders on the base surface.

[0030] S3, lay the first graded gravel cushion layer 1. The first graded gravel cushion layer 1 should be laid in layers, with each layer thickness not exceeding 20 cm, and ensure that the compaction degree meets the construction requirements. When the first graded gravel cushion layer 1 is laid to the set thickness, install the first geocell 2. In the process of laying the first geocell 2, the first geocell 2 should be fully opened to make it honeycomb-shaped. The overlap width of the first geocell 2 should not be less than 20 cm, and it should be fixed to the base with rivets or other connection methods. After the first geocell 2 is installed, continue to lay the first graded gravel cushion layer 1 to the set height.

[0031] S4, after the first graded gravel cushion layer 1 is laid, the first bidirectional geogrid 3 is laid. The first bidirectional geogrid 3 should be tightly fitted on the first graded gravel cushion layer 1 to avoid gaps or wrinkles to ensure that it effectively disperses the upper load. The first bidirectional geogrid 3 is fixed to the roadbed soil 91 and the abutment back fixing member 92 by plastic ground nails 93 to prevent it from moving during the construction process or later use.

[0032] S5, after the first bidirectional geogrid 3 is laid, the first foam lightweight soil layer 41 of the foam lightweight soil layer group 4 is poured. Before pouring, a protective wall should be set on the lateral free surface of the first foam lightweight soil layer 41 to ensure that it does not lose or deform during the pouring process. During the pouring process, a hose should be used for layered pumping to avoid damage or displacement of the geogrid. After pouring, the foam lightweight soil should be covered and protected in time and maintained, and the maintenance period should be no less than 7 days.

[0033] S6, after the curing period of the first layer of foam lightweight soil 41 is over, the third bidirectional geogrid 42 is laid, and the third bidirectional geogrid 42 is fixed to the roadbed soil 91 and the abutment back fixings 92 respectively by plastic ground nails 93 to prevent it from moving during the construction process or later use.

[0034] S7, after the third bidirectional geogrid 42 is laid, repeat steps S5-S6 until the required number of foam lightweight soil layers 41 reaches the target number, and then lay the second bidirectional geogrid 5 on the top foam lightweight soil layer 41 of the foam lightweight soil layer group 4.

[0035] S8, after the second bidirectional geogrid 5 is laid, the second graded crushed stone cushion layer 6 is laid to a set thickness, and the second geocell 7 is installed. After the second geocell 7 is installed, the second graded crushed stone cushion layer 6 is continued to be laid to a set height.

[0036] S9, after the second graded crushed stone cushion layer 6 is laid, the plain concrete stabilization layer 81 and the reinforced concrete slab 82 are constructed in sequence to complete the construction of the bridge head connection transition section.

[0037] In summary, the abutment back subgrade structure 100 of the utility model is effectively reinforced by setting the first bidirectional geogrid 3, the second bidirectional geogrid 5, the first geocell 2 and the second geocell 7, wherein the first bidirectional geogrid 3 and the second bidirectional geogrid 5 can control the shear strain in the subgrade soil 91, the first geocell 2 and the second geocell 7 can homogenize the stress distribution, and under the side limit of the three-dimensional honeycomb of the first geocell 2 and the second geocell 7, the first graded crushed stone cushion layer 1 can be increased. The bending strength of the second graded crushed stone cushion layer 6 can be improved and the settlement displacement and lateral displacement of the roadbed can be limited, thereby improving the settlement characteristics of the roadbed and improving the overall stability and bearing capacity of the roadbed. At the same time, by introducing the foam lightweight soil layer group 4 as filler, the dead weight of the roadbed can be effectively reduced. The third bidirectional geogrid 42 can effectively disperse the concentrated load and reduce the settlement cracks caused by the concentrated load of the foam lightweight soil layer group 4, thereby reducing the post-construction settlement of the bridge connection, improving the stability and bearing capacity of the roadbed, and ensuring the safety and comfort of driving.

[0038] The above disclosure is only a preferred example of the present invention, which cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the claims of the present invention are all within the scope of the present invention.

Claims

1. A bridge abutment back roadbed structure, characterized in that: The invention comprises a first graded gravel cushion, a first geocell, a first bidirectional geogrid, a foam lightweight soil layer group, a second bidirectional geogrid, a second graded gravel cushion, a second geocell and a concrete layer group. The first graded gravel cushion, the first bidirectional geogrid, the foam lightweight soil layer group, the second bidirectional geogrid, the second graded gravel cushion and the concrete layer group are arranged in sequence from bottom to top. The first geocell is arranged in the first graded gravel cushion, and the second geocell is arranged in the second graded gravel cushion.

2. The abutment back roadbed structure according to claim 1, characterized in that: One end of the first bidirectional geogrid is fixedly connected to the roadbed soil, and the other end of the first bidirectional geogrid is fixedly connected to the abutment back fixing piece.

3. The abutment back subgrade structure according to claim 2, characterized in that: The first bidirectional geogrid is fixedly connected to the roadbed soil and the abutment back fixing member through plastic ground nails.

4. The abutment back roadbed structure according to claim 1, characterized in that: One end of the second bidirectional geogrid is fixedly connected to the roadbed soil, and the other end of the second bidirectional geogrid is fixedly connected to the abutment back fixing piece.

5. The abutment back roadbed structure according to claim 4, characterized in that: The second bidirectional geogrid is fixedly connected to the roadbed soil and the abutment back fixing member through plastic ground nails.

6. The abutment back roadbed structure according to claim 1, characterized in that: The foam lightweight soil layer group includes a foam lightweight soil layer and a third bidirectional geogrid. Several layers of the foam lightweight soil layers are arranged in sequence from bottom to top. The bottom layer of the foam lightweight soil layer is arranged above the first bidirectional geogrid. The third bidirectional geogrid is arranged between the upper and lower adjacent foam lightweight soil layers. The top layer of the foam lightweight soil layer is located below the second bidirectional geogrid.

7. The abutment back roadbed structure according to claim 6, characterized in that: One end of the third bidirectional geogrid is fixedly connected to the roadbed soil, and the other end of the third bidirectional geogrid is fixedly connected to the abutment back fixing piece.

8. The abutment back roadbed structure according to claim 7, characterized in that: The third bidirectional geogrid is fixedly connected to the roadbed soil and the abutment back fixing parts respectively through plastic ground nails.

9. The abutment back roadbed structure according to claim 1, characterized in that: The concrete layer group includes a plain concrete stabilization layer and a reinforced concrete slab. The plain concrete stabilization layer is arranged above the second graded crushed stone cushion layer, and the reinforced concrete slab is arranged above the plain concrete stabilization layer.

10. The abutment back roadbed structure according to claim 1, characterized in that: A composite foundation composed of flexible piles and soil is provided below the first graded crushed stone cushion layer.

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