A stepped reinforcing structure for a reconstructed and expanded road bed joint

Abstract

The utility model discloses a kind of reconstruction and extension highway subgrade splicing place step type reinforcing structure, it is related to highway engineering technical field.The structure includes old subgrade and new subgrade, and old subgrade splicing side is opened multiple steps, and new subgrade filling is embedded step and forms occlusal structure;Step top surface is provided with the horizontal slope of inward inclination, and the included angle of vertical surface and horizontal plane is 60 °-80 °;Step is provided with anchoring hole at interval, and anchor rod is penetrated in hole, and one end is anchored in old subgrade, and the other end extends to new subgrade and is fixed by anchorage device.It also includes geogrid, V-shaped groove and convex occlusal structure, reinforced concrete rib beam, drainage system and foam light soil transition layer etc.The structure is strengthened by multiple measures new and old subgrade integrity, shear performance and drainage capacity, reduce settlement difference, effectively solve the disease problem existing in traditional splicing technology, improve highway stability and service life.

Description

Technical Field

[0001] This utility model relates to the field of highway engineering technology, and more specifically to a stepped reinforcement structure at the splicing point of the roadbed in the reconstruction and expansion of a highway. Background Technology

[0002] In highway reconstruction and expansion projects, the effective splicing of old and new roadbeds is a key link in ensuring the overall quality and service life of the highway. Because the old roadbed has become stable after long-term use, while the new roadbed will settle to a certain extent after filling, differential settlement can easily occur between the two, leading to problems such as pavement cracking and roadbed instability.

[0003] Currently, the commonly used method for roadbed splicing is stepped excavation, which increases the contact area between the old and new roadbeds to improve overall integrity. However, traditional stepped structures have many shortcomings, such as the top surface of the steps being mostly horizontal, which is not conducive to drainage and easily causes rainwater accumulation, affecting the stability of the roadbed; the interlocking degree between the side of the step and the new roadbed is insufficient, resulting in poor overall shear resistance; and the anchoring measures are inadequate, leading to insufficient connection strength between the old and new roadbeds. These problems make the splice area between the old and new roadbeds prone to various defects, affecting the normal use of the highway. Utility Model Content

[0004] The purpose of this utility model is to solve the technical problems existing in the current highway subgrade splicing technology, such as poor integrity between new and old subgrades, insufficient shear strength, poor drainage, and easy settlement differences. This utility model provides a stepped reinforcement structure for the splicing of subgrades in reconstructed and expanded highways that has a reasonable structure, high stability, and good drainage performance.

[0005] The technical solution adopted by this utility model is as follows: a stepped reinforcement structure at the splicing point of a reconstructed and expanded highway subgrade, including an old subgrade and a new subgrade. The splicing side of the old subgrade has multiple steps, and the new subgrade is filled and embedded in the steps to form an interlocking structure. The top surface of the steps has a transverse slope that slopes inward toward the subgrade, and the angle between the vertical plane and the horizontal plane is 60°-80°. Anchor holes are opened at intervals along the length direction in the steps, and anchor rods pass through the anchor holes. One end of the anchor rod is anchored inside the old subgrade, and the other end extends to the new subgrade and is fixed by an anchor.

[0006] Preferably, the width of the step is 1.5-2.5 meters, the height is 0.3-0.6 meters, and the slope of the cross slope is 2%-4%.

[0007] Preferably, the anchor rod is a threaded steel bar with a diameter of 22-32mm, the angle between its axis and the horizontal plane is 15°-45°, and the horizontal distance between adjacent anchor rods is 1.5-3.0 meters.

[0008] Preferably, a geogrid is laid between the top surface of the step and the contact surface of the new roadbed, and the width of the geogrid covers the full width of the step and extends at least 1.0 meter into the new roadbed.

[0009] Preferably, the overlap width of the geogrid layers on adjacent horizontal steps is not less than 0.5 meters, and the overlap is fixed with U-shaped nails.

[0010] Preferably, the vertical surface of the step is provided with a V-shaped groove, and the corresponding position of the new roadbed is provided with a protrusion structure that engages with the V-shaped groove.

[0011] Preferably, the new roadbed is provided with reinforced concrete ribs, the anchor is cast as a whole with the reinforced concrete ribs, and the position of the ribs corresponds to the extension end of the anchor rod.

[0012] Preferably, a longitudinal drainage blind pipe is provided at the bottom of the step, and the drainage blind pipe is connected to a transverse drainage pipe, which extends to the drainage ditch outside the roadbed slope.

[0013] Preferably, the drainage blind pipe is a perforated PVC pipe with a diameter of 100-150mm, filled with crushed stone filter material and wrapped with permeable geotextile; the longitudinal spacing of the transverse drainage pipe is 5-10 meters.

[0014] Preferably, the joint area between the new roadbed and the old roadbed is provided with a foamed lightweight soil transition layer, the top surface of which is flush with the top layer of the old roadbed and the new roadbed, and is compacted together to form an integral structure.

[0015] In summary, due to the adoption of the above technical solution, the beneficial effects of this utility model are:

[0016] This invention features multi-level steps on the splicing side of the old roadbed, with the new roadbed being filled and embedded to form an interlocking structure. Simultaneously, V-shaped grooves on the vertical surfaces of the steps engage with the raised structures of the new roadbed, significantly enhancing the integrity and shear resistance of the old and new roadbeds and effectively reducing relative displacement between them. The top surface of the steps has a transverse slope sloping inwards towards the roadbed, which, combined with drainage blind pipes and transverse drainage pipes at the bottom of the steps, allows for timely drainage of accumulated water from inside the roadbed, preventing rainwater accumulation and erosion, and improving the stability and durability of the roadbed.

[0017] The anchor bolts in this invention further strengthen the connection between the old and new roadbeds. The reinforced concrete ribs and anchorages are cast as a single unit, enhancing the anchoring effect and creating a solid whole between the old and new roadbeds. The laying of geogrids effectively disperses stress, reduces roadbed deformation, and improves the roadbed's crack resistance; the overlapping of adjacent geogrids ensures overall load-bearing capacity. The foamed lightweight soil transition layer is characterized by its light weight, high strength, and low compressibility, effectively reducing settlement differences between the old and new roadbeds and preventing pavement cracking and other defects. Attached Figure Description

[0018] This utility model will be described by way of example and with reference to the accompanying drawings, wherein:

[0019] Figure 1 This is a schematic diagram of the cross-sectional structure of this utility model;

[0020] Figure 2 This is an enlarged structural diagram of point A of this utility model;

[0021] Figure 3 This is a schematic diagram of the pretreatment state of the old roadbed before cast-in-place concrete, which is a utility model.

[0022] The markings in the diagram are as follows: 1-Old roadbed, 2-New roadbed, 201-Raised structure, 3-Step, 301-Cross slope, 302-V-shaped groove, 4-Anchor hole, 5-Anchor rod, 6-Anchor, 7-Geogrid, 8-Drainage blind pipe, 9-Transverse drainage pipe. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can typically be arranged and designed in various different configurations.

[0024] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0025] In one embodiment of this utility model, such as Figure 1-3 As shown, this embodiment provides a stepped 3-type reinforcement structure for the splicing of roadbed in a reconstructed and expanded highway, including an old roadbed 1 and a new roadbed 2. The splicing side of the old roadbed 1 has multiple steps 3, and the new roadbed 2 is filled and embedded in the steps 3 to form an interlocking structure. The top surface of the steps 3 is provided with a transverse slope 301 that slopes inward toward the roadbed, and the angle between the vertical plane and the horizontal plane is 60°-80°. Anchor holes 4 are opened at intervals along the length direction in the steps 3, and anchor rods 5 pass through the anchor holes 4. One end of the anchor rod 5 is anchored inside the old roadbed 1, and the other end extends to the new roadbed 2 and is fixed by an anchor 6.

[0026] In another embodiment of this utility model, the width of the step 3 is 1.5-2.5 meters, the height is 0.3-0.6 meters, and the slope of the cross slope 301 is 2%-4%.

[0027] In another embodiment of this utility model, the anchor rod 5 is a threaded steel bar with a diameter of 22-32mm, the angle between its axis and the horizontal plane is 15°-45°, and the horizontal distance between adjacent anchor rods 5 is 1.5-3.0 meters.

[0028] In another embodiment of the present invention, a geogrid 7 is laid between the top surface of the step 3 and the contact surface of the new roadbed 2, and the width of the geogrid 7 covers the full width of the step 3 and extends at least 1.0 meter into the new roadbed 2.

[0029] In another embodiment of this utility model, the overlap width of the 7 layers of geogrid on adjacent horizontal steps 3 is not less than 0.5 meters, and the overlap is fixed with U-shaped nails.

[0030] In another embodiment of the present invention, the vertical surface of the step 3 is provided with a V-shaped groove 302, and the new roadbed 2 is provided with a protrusion structure 201 that engages with the V-shaped groove 302 at the corresponding position.

[0031] In another embodiment of this utility model, the new roadbed 2 is provided with reinforced concrete ribs, the anchor 6 is cast as a whole with the reinforced concrete ribs, and the position of the ribs corresponds to the extension end of the anchor rod 5.

[0032] In another embodiment of the present invention, a longitudinal drainage blind pipe 8 is provided at the bottom of the step 3, the drainage blind pipe 8 is connected to a transverse drainage pipe 9, and the transverse drainage pipe 9 extends to the drainage ditch outside the roadbed slope.

[0033] In another embodiment of this utility model, the drainage blind pipe 8 is a perforated PVC pipe with a diameter of 100-150mm, the outer periphery is filled with crushed stone filter material and wrapped with permeable geotextile; the longitudinal spacing of the transverse drainage pipes 9 is 5-10 meters.

[0034] In another embodiment of this utility model, a foamed lightweight soil transition layer is provided in the splicing area between the new roadbed 2 and the old roadbed 1. Its top surface is flush with the top layer of the old roadbed 1 and the new roadbed 2, and they are rolled together to form an integral structure.

[0035] The construction process of this utility model is as follows:

[0036] 1. Excavate the slope of the old roadbed 1 to form multiple steps 3. Taking a width of 1.8 meters and a height of 0.4 meters as an example, adjust the cross slope 301 to a 3% slope and the vertical angle to 70°.

[0037] 2. A V-shaped groove 302 is mechanically chiseled on the vertical surface of step 3;

[0038] 3. Drill anchor holes 4 with a horizontal spacing of 2.0 meters, insert Φ28mm threaded steel bars, preferably at an inclination angle of 30°, and grout anchor at one end of the old roadbed;

[0039] 4. Lay longitudinal drainage blind pipes 8, using Φ120mm PVC pipes, wrap them with geotextile and fill them with gravel, and connect them to transverse drainage pipes 9, with a spacing of 8 meters.

[0040] 5. Lay geogrid 7, cover step 3 and extend it outward by 1.2 meters, with the geogrid of adjacent steps 3 overlapping by 0.6 meters and fixed with U-shaped nails;

[0041] 6. The new roadbed 2 is filled in layers, and the exposed ends of the anchor bolts 5 are inserted into the precast reinforced concrete rib beams and then tensioned and locked.

[0042] 7. The joint area shall be filled with lightweight foamed soil with a density ≤ 5 kN / m³. 3 The top surface of the new and old roadbeds was compacted simultaneously.

[0043] Through stepped interlocking, three-dimensional anchoring, and integrated waterproofing and drainage design, the structure achieves efficient and coordinated stress distribution between the old and new roadbeds, significantly improving the long-term stability of the reconstructed and expanded highway.

[0044] The above are merely preferred embodiments of this utility model and do not limit the patent scope of this utility model. Any equivalent structural transformations made based on the concept of this utility model and the contents of the specification and drawings of this utility model, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this utility model.

Claims

1. A stepped reinforcement structure for the joint of roadbed in the reconstruction and expansion of a highway, comprising an old roadbed (1) and a new roadbed (2), characterized in that: The old roadbed (1) has multiple steps (3) on the splicing side, and the new roadbed (2) is filled and embedded in the steps (3) to form an interlocking structure; The top surface of the step (3) is provided with a cross slope (301) that slopes inward toward the roadbed; Anchor holes (4) are opened at intervals along the length direction in the step (3). Anchor rods (5) pass through the anchor holes (4). One end of the anchor rod (5) is anchored inside the old roadbed (1), and the other end extends to the new roadbed (2) and is fixed by the anchor (6).

2. The stepped reinforcing structure for the joint of the reconstructed highway subgrade according to claim 1, characterized in that: The step (3) is 1.5-2.5 meters wide and 0.3-0.6 meters high, and the slope of the cross slope (301) is 2%-4%.

3. The stepped reinforcement structure at the joint of the roadbed in the reconstruction and expansion of a highway as described in claim 1, characterized in that: The anchor rod (5) is a threaded steel bar with a diameter of 22-32mm. Its axis makes an angle of 15°-45° with the horizontal plane, and the horizontal distance between adjacent anchor rods (5) is 1.5-3.0 meters.

4. The stepped reinforcement structure at the joint of the roadbed in the reconstruction and expansion of a highway as described in claim 1, characterized in that: A geogrid (7) is laid between the top surface of the step (3) and the contact surface of the new roadbed (2), and the width of the geogrid (7) covers the full width of the step (3) and extends at least 1.0 meter into the new roadbed (2).

5. The stepped reinforcement structure at the joint of the roadbed in the reconstruction and expansion of a highway as described in claim 4, characterized in that: The overlap width of the geogrid layer on the adjacent horizontal steps (3) shall not be less than 0.5 meters, and the overlap shall be fixed with U-shaped nails.

6. The stepped reinforcement structure at the joint of the roadbed in the reconstruction and expansion of a highway as described in claim 1, characterized in that: The vertical surface of the step (3) is provided with a V-shaped groove (302), and the new roadbed (2) is provided with a protrusion (201) that engages with the V-shaped groove (302) at the corresponding position.

7. The stepped reinforcement structure at the joint of the roadbed in the reconstruction and expansion of a highway as described in claim 1, characterized in that: The new roadbed (2) is equipped with reinforced concrete ribs, and the anchor (6) is cast as a whole with the reinforced concrete ribs, and the position of the ribs corresponds to the extension end of the anchor rod (5).

8. The stepped reinforcement structure at the joint of the roadbed in the reconstruction and expansion of a highway according to claim 1, characterized in that: The bottom of the step (3) is provided with a longitudinal drainage blind pipe (8), which is connected to a transverse drainage pipe (9). The transverse drainage pipe (9) extends to the drainage ditch outside the roadbed slope.

9. The stepped reinforcement structure at the joint of the roadbed in the reconstruction and expansion of a highway as described in claim 8, characterized in that: The drainage blind pipe (8) is a PVC pipe with a diameter of 100-150mm and has holes. The outer perimeter is filled with crushed stone filter material and wrapped with permeable geotextile. The longitudinal spacing of the transverse drainage pipes (9) is 5-10 meters.

10. The stepped reinforcement structure at the joint of the roadbed in the reconstruction and expansion of a highway according to claim 1, characterized in that: The splicing area between the new roadbed (2) and the old roadbed (1) is provided with a foamed lightweight soil transition layer, the top surface of which is flush with the top layer of the old roadbed (1) and the new roadbed (2), and is rolled together to form an integral structure.

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