New and old roadbed lap joint structure and construction method

Abstract

The invention provides a new and old roadbed lap joint structure and a construction method, and belongs to the technical field of new and old roadbed lap joint, the new and old roadbed lap joint structure comprises an old roadbed body, flow state solidified soil, a new roadbed body and a plurality of geogrids, and the new roadbed body and the old roadbed body are fixedly lapped through the inserted geogrids and the filled flow state solidified soil. The new roadbed body comprises a plurality of lap joint layers, the first lap joint layer is laid at the stepped end of the old roadbed body, the geogrid is inserted between the first lap joint layer and the horizontal step of the old roadbed body, and a filling area formed by the first lap joint layer and the horizontal step of the old roadbed body is filled with flow state solidified soil. And after the flow-state solidified soil is solidified, the steps are repeated until the upper end face of the uppermost lap joint layer is laid to be flush with the upper end face of the old roadbed body, the uppermost lap joint layer is in lap joint with the old roadbed body through the flow-state solidified soil, and therefore fixed lap joint between the new roadbed body and the old roadbed body is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of overlapping new and old roadbeds, and in particular relates to an overlapping structure of new and old roadbeds and a construction method. Background Art

[0002] In the overlap of the new and old roadbeds, the settlement of the old roadbed has become stable after nearly ten years of operation and long-term load, while the new roadbed will inevitably go through a settlement process after its formation, resulting in uneven settlement at the connection between the new and old roadbeds when the new and old roadbeds are overlapped.

[0003] At present, after the new and old roadbeds are overlapped, only the new roadbed is compacted. However, since the new roadbed still needs to go through a settlement process after compaction, there will still be uneven settlement at the connection between the new roadbed and the old roadbed after a period of compaction.

[0004] Therefore, the deficiency of the prior art is that, during the construction process of the new and old roadbeds, the existing overlap of the new and old roadbeds cannot solve the problem of uneven settlement at the connection between the new and old roadbeds. Summary of the invention

[0005] In view of the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide a new and old roadbed overlap structure and construction method, which is used to solve the problem of uneven settlement at the connection between the new and old roadbeds after overlapping for a period of time in the prior art.

[0006] In order to achieve the above-mentioned object and other related objects, the present invention provides a new and old roadbed overlap structure, the overlap structure comprising: An old road base body, fluidized solidified soil, a new road base body and a plurality of geogrids, a filling area is left between the old road base body and the new road base body, and the geogrids are inserted in the filling area between the new road base body and the old road base body; The fluidized solidified soil is filled in the filling area between the new road base body and the old road base body, and the fluidized solidified soil wraps the geogrid, and the fluidized solidified soil fixedly connects the new road base body and the old road base body.

[0007] As an optional solution, the overlapping surface of the old road basic body is in a step shape.

[0008] As an optional solution, the new road base body includes several overlapping layers, and two adjacent overlapping layers are overlapped and compacted. Each geogrid is horizontally inserted between each overlapping layer and the old road base body, and each overlapping layer is fixedly connected to a step horizontal to the old road base body through fluidized solidified soil.

[0009] As an optional solution, the geogrid includes transverse bars, longitudinal bars and vertical bars, the transverse bars and longitudinal bars are located in the same horizontal plane, the connection between the transverse bars and the longitudinal bars are fixed with vertical bars, and the vertical bars are perpendicular to the plane where the transverse bars and the longitudinal bars are located.

[0010] As an optional solution, the upper end surface of each overlapping layer is smaller than the lower end surface; A portion of the lower end surface of the upper overlapping layer of the two adjacent overlapping layers is compacted on the upper end surface of the lower overlapping layer, and another portion of the lower end surface of the upper overlapping layer is compacted on the fluidized solidified soil fixedly connected to the lower overlapping layer.

[0011] As an optional solution, the upper end surface of the new road base body is flush with the upper end surface of the old road base body, and the lower end surface of the new road base body is flush with the lower end surface of the old road base body.

[0012] As an optional solution, the fluidized solidified soil includes high liquid limit clay, fly ash, cement, water reducing agent and water.

[0013] The present invention also provides a method for overlapping a new and old roadbed, including the above-mentioned overlapping structure of the new and old roadbed, and the overlapping construction method includes: Preparation steps: Dig out the sidewall of the old road base body on the side that needs to be widened into a step shape; Mixing step: mixing high liquid limit clay, fly ash, cement, water reducing agent and water in proportion to form fluidized solidified soil; Overlapping steps: laying the first overlapping layer on the stepped end of the old road basic body, drilling holes in the first overlapping layer, drilling holes in the step where the old road basic body and the first overlapping layer are level, respectively inserting the two ends of the transverse grid into the holes drilled on the step where the first overlapping layer and the old road basic body are level, filling the filling area formed by the step where the first overlapping layer and the old road basic body are level with each other with fluidized solidified soil, after the fluidized solidified soil fixes the first overlapping layer and the old road basic body, repeating the above steps until the upper end face of the top overlapping layer is flush with the upper end face of the old road basic body, and the top overlapping layer is overlapped on the old road basic body through the fluidized solidified soil, thereby realizing the laying of the new road basic body and the fixed overlap between the new road basic body and the old road basic body.

[0014] As an optional solution, in the overlapping step, the vertical bars of the geogrid located in the lower layer in two adjacent overlapping layers extend out of the upper end surface of the filling area of ​​the lower layer.

[0015] As described above, the new-old roadbed overlap structure and construction method of the present invention have at least the following beneficial effects: 1. In the present invention, the new road base body and the old road base body are plugged together by geogrids, and the filling area formed between the new road base body and the old road base body is fixedly connected by fluidized solidified soil, so that uneven settlement will not occur at the connection between the new road base body and the old road base body.

[0016] 2. The geogrid inserted between the new road base body and the old road base body of the present invention can not only enhance the horizontal stability between the new road base body and the old road base body through transverse bars and longitudinal bars, but also enhance the vertical stability between the new road base body and the old road base body through vertical bars.

[0017] 3. By comparing the fluidity and compressive strength of fluidized solidified soils with different mix ratios, the present invention obtains that the optimal mix ratio of high liquid limit clay, fly ash, cement, water reducer and water in the solidified soil is 200:15:40:3:130. The fluidized solidified soil is filled between the new road base body and the old road base body, thereby enhancing the stability between the new road base body and the old road base body, so that there will be no uneven settlement between the new road base body and the old road base body. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It shows a cross-sectional schematic diagram of the overlapping structure of the new and old roadbed of the present invention; Figure 2 It is a cross-sectional schematic diagram showing the overlap of the first overlap layer of the present invention and the basic body of the old road; Figure 3 Shown as the present invention Figure 2 A local enlarged view of point A in FIG. Figure 4 A schematic cross-sectional view showing a second overlapping layer of the present invention being compacted on the first overlapping layer; Figure 5 Shown as the present invention Figure 4 A local enlarged view of point B in FIG. Figure 6 Shown is a partial cross-sectional view of the geogrid of the present invention.

[0019] In the figure: 101, basic body of old road; 102, fluidized solidified soil; 103, filling area; 201, overlapping layer; 301, horizontal bars; 302, longitudinal bars; 303, vertical bars. DETAILED DESCRIPTION

[0020] The following is a description of the implementation of the present invention by means of specific embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0021] See also Figures 1 to 6 . It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no substantial technical significance. Any modification of the structure, change in the proportional relationship, or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the effects and purposes that can be achieved by the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the present invention. Changes or adjustments in their relative relationships should also be regarded as the scope of the implementation of the present invention without substantially changing the technical content.

[0022] The following embodiments are only for illustration purposes and can be combined with each other, and are not limited to the contents presented in the following single embodiments.

[0023] See also Figure 1 , Figure 2 , Figure 3 and Figure 6 The present invention provides a new and old roadbed overlap structure, the overlap structure comprising: An old road base body 101, fluidized solidified soil 102, a new road base body and a plurality of geogrids, a filling area 103 is left between the old road base body 101 and the new road base body, and the geogrids are inserted into the filling area 103 between the new road base body and the old road base body 101; The fluidized solidified soil 102 is filled in the filling area 103 between the new road base body and the old road base body 101 , and the fluidized solidified soil 102 wraps the geogrid, and the fluidized solidified soil 102 fixedly connects the new road base body and the old road base body 101 .

[0024] In this embodiment, the new road base body and the old road base body 101 are plugged together through the geogrid, and the filling area 103 between the new road base body and the old road base body 101 is filled with fluidized solidified soil 102, so that the fluidized solidified soil 102 wraps the geogrid, thereby achieving the overlap between the new road base body and the old road base body 101.

[0025] The new road base body and the old road base body 101 of the present invention are connected together by geogrids, and the filling area 103 formed between the new road base body and the old road base body 101 is fixedly connected by fluidized solidified soil 102, so that uneven settlement will not occur at the connection between the new road base body and the old road base body 101.

[0026] See also Figure 2The overlapping surface of the old road basic body 101 is in a step shape.

[0027] In this embodiment, the side wall of the old road basic body 101 on the side that needs to be widened is excavated into a step shape, waiting for subsequent operations.

[0028] The present invention digs the contact surface of the overlapping surface into a step shape when overlapping the old road basic body 101, thereby increasing the contact area between the old road basic body 101 and the fluidized solidified soil 102 when overlapping the new road basic body, thereby increasing the overlapping strength between the new road basic body and the old road basic body 101.

[0029] See also Figure 1 and Figure 6 The new road base body includes several overlapping layers 201, and two adjacent overlapping layers 201 are overlapped and compacted. Each geogrid is horizontally inserted between each overlapping layer 201 and the old road base body 101, and each overlapping layer 201 is fixedly connected to the step horizontal to the old road base body 101 through the fluidized solidified soil 102.

[0030] In this embodiment, each of the overlapping layers 201 is plugged together with a step horizontal to the old road base body 101 through a geogrid, and each of the overlapping layers 201 is fixedly connected to a step horizontal to the old road base body 101 through the fluidized solidified soil 102 .

[0031] The present invention can independently insert the geogrid and fix the fluidized solidified soil 102 between each overlapping layer 201 and the old road base body 101 , thereby enhancing the stability of the new road base body and the old road base body 101 .

[0032] See also Figure 6 The geogrid includes transverse bars 301, longitudinal bars 302 and vertical bars 303. The transverse bars 301 and longitudinal bars 302 are located in the same horizontal plane. The connection between the transverse bars 301 and the longitudinal bars 302 is fixed with vertical bars 303. The vertical bars 303 are perpendicular to the plane where the transverse bars 301 and the longitudinal bars 302 are located.

[0033] In this embodiment, when inserting the geogrid into the filling area 103 between the new road base body and the old road base body 101, the transverse bars 301 of the geogrid are horizontally inserted between the new road base body and the old road base body 101, and the vertical bars 303 are perpendicular to the plane where the transverse bars 301 and the longitudinal bars 302 are located, thereby completing the insertion of the geogrid between the new road base body and the old road base body 101.

[0034] The geogrid of the present invention can not only enhance the horizontal stability between the new road base body and the old road base body 101 through the transverse bars 301 and the longitudinal bars 302 , but also enhance the vertical stability between the new road base body and the old road base body 101 through the vertical bars 303 .

[0035] See also Figure 4 and Figure 5 , the upper end surface of each of the overlapping layers 201 is smaller than the lower end surface; A portion of the lower end surface of the upper overlapping layer 201 of the two adjacent overlapping layers 201 is compacted on the upper end surface of the lower overlapping layer 201, and another portion of the lower end surface of the upper overlapping layer 201 is compacted on the fluidized solidified soil 102 fixedly connected to the lower overlapping layer 201.

[0036] In this embodiment, when the upper overlapping layer 201 is laid on the upper end surface of the lower overlapping layer, the lower end surface of the upper overlapping layer 201 is covered on the fluidized solidified soil 102 to which the upper end surface of the lower overlapping layer 201 and the lower overlapping layer 201 are fixedly connected, and then the upper overlapping layer 201 is compacted.

[0037] When laying the upper overlapping layer 201, the present invention can compact the fluidized solidified soil 102 fixedly connected to the lower overlapping layer 201, and the structural design is ingenious.

[0038] See also Figure 1 The upper end surface of the new road basic body is flush with the upper end surface of the old road basic body 101 , and the lower end surface of the new road basic body is flush with the lower end surface of the old road basic body 101 .

[0039] In this embodiment, when overlapping the old road base body 101, the lower end surface of the lowest overlapping layer 201 is laid flush with the lower end surface of the old road base body 101, and the upper end surface of the highest overlapping layer 201 is laid flush with the upper end surface of the old road base body 101.

[0040] The present invention only increases the width of the old road basic body 101 after the new road basic body is overlapped, and does not change the height of the widened new road basic body relative to the old road basic body 101, so as to ensure that the height of the new road basic body is consistent with the height of the old road basic body 101.

[0041] See also Figure 1 The fluidized solidified soil 102 includes high liquid limit clay, fly ash, cement, water reducing agent and water.

[0042] In this embodiment, high liquid limit clay, fly ash, cement, water reducing agent and water are mixed in proportion to form fluidized solidified soil 102 , waiting for the subsequent use of the fluidized solidified soil 102 .

[0043] The present invention can fill the filling area 103 between the new road base body and the old road base body 101 with a fluidized solidified soil 102 mixed in proportion with high liquid limit clay, fly ash, cement, water reducer and water, thereby avoiding uneven settlement at the connection between the new road base body and the old road base body 101.

[0044] See also Figures 1 to 6 The present invention also provides a method for overlapping a new and old roadbed, including the above-mentioned overlapping structure of a new and old roadbed, and the overlapping construction method includes: Preparation step: dig the side wall of the old road basic body 101 on the side that needs to be widened into a step shape; In the preparation step, taking a typical highway widening project as an example, the section 101 of the old road basic body is an isosceles trapezoid with an upper base of 26m, a lower base of 38m, a waist and a height of 7.5m and 4m respectively, and the length and height of the step section are 1m and 0.8m respectively; Mixing step: mixing high liquid limit clay, fly ash, cement, water reducing agent and water in proportion to form fluidized solidified soil 102; In the mixing step, by comparing the fluidity and compressive strength of the fluidized solidified soil 102 with different mix ratios, it is concluded that the mix ratio of high liquid limit clay, fly ash, cement, water reducer and water in the solidified soil is 200:15:40:3:130, and the fluidized solidified soil 102 is prepared by mixing high liquid limit clay, fly ash, cement, water reducer and water according to the optimal mix ratio; Overlapping step: laying the first overlapping layer 201 on the end of the old road base body 101 where a step is dug out, drilling the first overlapping layer 201 with a drilling device such as a geological exploration drill or an engineering drill, drilling the step where the old road base body 101 and the first overlapping layer 201 are horizontal, inserting the two ends of the transverse grid 301 into the holes drilled on the step where the first overlapping layer 201 and the old road base body 101 are horizontal, forming a filling area 103 on the step where the first overlapping layer 201 and the old road base body 101 are horizontal, and filling area 103 is formed in the filling area 103. 03 is filled with fluidized solidified soil 102 by a concrete pump truck. After the fluidized solidified soil 102 fixes the first overlapping layer 201 and the old road basic body 101, a vibrating roller or a static pressure roller is used to compact the new road basic body. The above steps are repeated until the upper end surface of the top overlapping layer 201 is flush with the upper end surface of the old road basic body 101, and the top overlapping layer 201 is overlapped on the old road basic body 101 through the fluidized solidified soil 102, thereby achieving the paving of the new road basic body and the fixed overlap between the new road basic body and the old road basic body 101; In the overlapping step, taking the Nanchang to Zhangshu Expressway expansion and reconstruction project as an example, the cross-section of the overlapping layer 201 is an isosceles trapezoid with an upper base of 7.5m, a lower base of 9.9m, a waist and a height of 1.4m and 0.8m respectively. The cross-section of the filling area is an inverted right-angled trapezoid with an upper base of 1m, a lower base of 2.2m, a waist and a height of 1.4m and 0.8m respectively. During construction, the old road base body 101 is widened for 5m at a time.

[0045] See also Figures 2 to 5 In the overlapping step, the vertical bars 303 of the geogrid located in the lower layer in two adjacent overlapping layers 201 extend out of the upper end surface of the filling area 103 of the lower layer.

[0046] In this embodiment, when the geogrid is inserted into the holes drilled on the step where one of the overlapping layers 201 is horizontal with the old road basic body 101 through the two ends of the transverse bars 301, the geogrid is located in the filling area 103 formed by the step where the overlapping layer 201 is horizontal with the old road basic body 101, and the vertical bars 303 in the geogrid extend upward from the filling area 103 formed by the step where the overlapping layer 201 is horizontal with the old road basic body 101. When the overlapping layer 201 above the overlapping layer 201 is laid, the vertical bars 303 will be inserted into the overlapping layer 201 above the overlapping layer 201 and fixed during the laying process.

[0047] The geogrid of the present invention can not only connect the overlapping layer 201 with the filling area 103 formed by the steps horizontal to the old road base body 101, but also connect the overlapping layer 201 of the upper layer through the vertical bars 303 in the geogrid, thereby enhancing the stability between the new road base body and the old road base body 101.

[0048] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A new and old roadbed overlap structure, characterized in that: The overlapping structure comprises: An old road base body, fluidized solidified soil, a new road base body and a plurality of geogrids, a filling area is left between the old road base body and the new road base body, and the geogrids are inserted in the filling area between the new road base body and the old road base body; The fluidized solidified soil is filled in the filling area between the new road base body and the old road base body, and the fluidized solidified soil wraps the geogrid, and the fluidized solidified soil fixedly connects the new road base body and the old road base body.

2. A new and old roadbed overlap structure according to claim 1, characterized in that: The overlapping surface of the old road basic body is in a step shape.

3. A new and old roadbed overlap structure according to claim 2, characterized in that: The new road base body includes several overlapping layers, and two adjacent overlapping layers are overlapped and compacted. Each geogrid is horizontally inserted between each overlapping layer and the old road base body, and each overlapping layer is fixedly connected to the steps horizontal to the old road base body through fluidized solidified soil.

4. The new and old roadbed overlap structure according to claim 1, characterized in that: The geogrid includes transverse bars, longitudinal bars and vertical bars. The transverse bars and longitudinal bars are located in the same horizontal plane. Vertical bars are fixed at the connection between the transverse bars and the longitudinal bars. The vertical bars are perpendicular to the plane where the transverse bars and the longitudinal bars are located.

5. The new and old roadbed overlap structure according to claim 3, characterized in that: The upper end surface of each overlapping layer is smaller than the lower end surface; A portion of the lower end surface of the upper overlapping layer of the two adjacent overlapping layers is compacted on the upper end surface of the lower overlapping layer, and another portion of the lower end surface of the upper overlapping layer is compacted on the fluidized solidified soil fixedly connected to the lower overlapping layer.

6. The new and old roadbed overlap structure according to claim 2, characterized in that: The upper end surface of the new road basic body is flush with the upper end surface of the old road basic body, and the lower end surface of the new road basic body is flush with the lower end surface of the old road basic body.

7. The new and old roadbed overlap structure according to claim 1, characterized in that: The fluidized solidified soil comprises high liquid limit clay, fly ash, cement, water reducing agent and water.

8. A construction method for overlapping a new and old roadbed, comprising an overlapping structure of a new and old roadbed as claimed in any one of claims 1 to 7, characterized in that: The overlapping construction method comprises: Preparation steps: Dig out the side wall of the old road base body on the side that needs to be widened into a step shape; Mixing step: mixing high liquid limit clay, fly ash, cement, water reducing agent and water in proportion to form fluidized solidified soil; Overlapping steps: laying the first overlapping layer on the stepped end of the old road basic body, drilling holes in the first overlapping layer, drilling holes in the step where the old road basic body and the first overlapping layer are level, respectively inserting the two ends of the transverse grid into the holes drilled on the step where the first overlapping layer and the old road basic body are level, filling the filling area formed by the step where the first overlapping layer and the old road basic body are level with each other with fluidized solidified soil, after the fluidized solidified soil fixes the first overlapping layer and the old road basic body, repeating the above steps until the upper end face of the top overlapping layer is flush with the upper end face of the old road basic body, and the top overlapping layer is overlapped on the old road basic body through the fluidized solidified soil, thereby realizing the laying of the new road basic body and the fixed overlap between the new road basic body and the old road basic body.

9. A construction method for overlapping a new and old roadbed according to claim 8, characterized in that: In the overlapping step, the vertical bars of the geogrid located in the lower layer in two adjacent overlapping layers extend out of the upper end surface of the filling area of ​​the lower layer.

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