An assembled bridge head structure and a construction method thereof
By combining prefabricated approach slab structures and jacking devices, the problem of roadbed settlement under vehicle loads in bridge abutment structures was solved, enabling rapid repair and reinforcement of bridge abutment structures and improving driving safety and construction efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SHANDONG HI SPEED CONSTRUCTION MANAGEMENT GROUP CO LTD
- Filing Date
- 2026-05-09
- Publication Date
- 2026-07-21
AI Technical Summary
Existing bridge abutment structures are prone to roadbed settlement under uneven vehicle loads, and once settlement occurs, it is difficult to effectively repair, affecting driving safety and comfort.
The bridge adopts a precast approach slab structure, which is connected to the abutment. A lifting device is installed at the lower end of the approach slab. It is connected to the roadbed through grouting holes and steel pipes. The lifting device is used to lift the approach slab and inject grout to fill the void when the roadbed settles to the preset value. Combined with the self-stressing concrete section, the structural stability is improved.
Effective repair and reinforcement of bridge abutment structures reduces roadbed settlement, improves driving safety and comfort, shortens construction period, and reduces on-site work.
Smart Images
Figure CN122428563A_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the technical field of road-bridge transition section structure in bridge engineering, and particularly relates to a prefabricated bridge abutment structure and its construction method. Background Technology
[0002] In the transition section of a road and bridge, approach slabs are usually used for connection. Due to the difference in stiffness between the abutment and the roadbed, uneven settlement of the roadbed is easily caused by repeated vehicle loads, resulting in bridge approach slabs and affecting driving safety and comfort.
[0003] Currently, traditional bridge abutment slabs mostly use cast-in-place reinforced concrete structures, which, while offering good overall integrity, involve long construction periods and a large amount of on-site work. Therefore, existing technologies employ prefabricated bridge abutment slab structures, using precast concrete slabs that are assembled on-site via hoisting to improve construction efficiency. However, existing prefabricated slabs are typically laid directly after the roadbed has been compacted, but under uneven vehicle loads, the roadbed can still experience further settlement, which is difficult to repair once it occurs. Summary of the Invention
[0004] The purpose of this application is to provide a prefabricated bridge abutment structure and its construction method, which aims to solve the problem that the roadbed of existing bridge abutment structures will still settle further under uneven vehicle loads, and it is difficult to repair the settlement after it occurs.
[0005] This application embodiment is implemented as follows: a prefabricated bridge abutment structure includes: an abutment, a roadbed, an approach slab, and a lifting device; the approach slab is a prefabricated approach slab, a first end of the approach slab is connected to the abutment, and a second end of the approach slab is erected on the roadbed; the approach slab has grouting holes, the grouting holes are connected to steel pipes, the steel pipes extend into the roadbed, and the pipe walls of the steel pipes have grout outlet holes; the lifting device is pre-embedded in the roadbed and located below the second end of the approach slab, and the output end of the lifting device is connected to the second end of the approach slab to drive the second end of the approach slab to rise and fall.
[0006] Preferably, the roadbed is also pre-embedded with a fixing plate, and the lifting device is fixedly mounted on the fixing plate.
[0007] Preferably, the approach slab includes a conventional concrete section and two self-stressing concrete sections, the two self-stressing concrete sections being located at the first end and the second end of the approach slab, respectively, and the self-stressing concrete sections are cast from self-stressing concrete.
[0008] Preferably, the grouting holes are provided in two sets, one set of grouting holes is close to the first end of the slab, and the other set of grouting holes is close to the second end of the slab.
[0009] Preferably, two planks are arranged side by side, and the joint between the two planks is sealed with self-stressing concrete.
[0010] Preferably, a support plate is provided along the joint of the two approach slabs on the roadbed, the support plate abuts against the two approach slabs, and a plurality of concrete columns extending into the roadbed are fixed to the support plate.
[0011] Preferably, a guide positioning component is fixedly provided on the bridge platform, the guide positioning component has a guide groove, and the first end of the approach plate is formed with a limiting part that is slidably disposed in the guide groove. The limiting parts of both approach plates cooperate with the guide groove so that the two approach plates are flush.
[0012] Another objective of this application is to provide a construction method for a prefabricated bridge abutment structure, including: Precast slabs; Pre-embed lifting devices within the roadbed; The prefabricated slabs are hoisted, and the first end of the slab is connected to the bridge abutment, while the second end is connected to the output end of the jacking device. Drill grouting holes in the slab and lower steel pipes; When the roadbed settlement rate drops to the preset value, the jacking device lifts the approach slab to be flush with the bridge deck and injects grout through the grouting hole to fill the gap between the roadbed and the approach slab.
[0013] Preferably, the method for making the slab includes: first pouring a section of ordinary concrete, curing it to the predetermined strength, and then pouring self-stressed concrete sections at both ends of the ordinary concrete section.
[0014] Preferably, the method of injecting grout through grouting holes includes: injecting micro-expansion cement grout into the grouting hole near the abutment and injecting reinforcing mud into the grouting hole near the roadbed.
[0015] This application provides a prefabricated bridge abutment structure in which a lifting device is pre-embedded in the roadbed. After the bridge abutment has been in operation for a period of time, the roadbed is further compacted and settles under the pressure of vehicle loads. When the settlement rate drops to a preset value, the second end of the approach slab is lifted to be flush with the bridge deck by the lifting device, and grout is injected through the grouting hole to fill the void, thereby repairing and reinforcing the bridge abutment. Attached Figure Description
[0016] Figure 1 This is a schematic diagram of a prefabricated bridge abutment structure provided in an embodiment of this application; Figure 2 This is a schematic diagram of another view of a prefabricated bridge abutment structure provided in an embodiment of this application; Figure 3 This is a schematic diagram of the lifting device provided in the embodiments of this application; Figure 4 A schematic diagram of the joint structure of the two overlapping plates provided in an embodiment of this application; Figure 5 This is a schematic diagram of the structure of the guide positioning component provided in the embodiments of this application.
[0017] In the picture: 100. Bridge abutment; 200. Approach slab; 210. Ordinary concrete section; 220. Self-stressing concrete section; 230. Joint; 310. Lifting device; 320. Fixing plate; 330. Controller; 400. Steel perforated pipe; 500. Guide positioning component; 510. Guide groove; 600. Support plate; 700. Concrete column. Detailed Implementation
[0018] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.
[0019] The specific implementation of this application will be described in detail below with reference to specific embodiments.
[0020] like Figure 1 and Figure 2 The diagram shown is a structural schematic of a prefabricated bridge abutment structure provided in an embodiment of this application, including: abutment 100, roadbed, approach slab 200 and lifting device 310; the approach slab 200 is a prefabricated approach slab.
[0021] The first end of the approach slab 200 is connected to the abutment 100, and the second end of the approach slab 200 is laid on the roadbed. In this embodiment, the approach slab 200 is prefabricated in the factory and then transported to the site for hoisting. One end of the approach slab 200 is fixed to the abutment 100, and the other end is laid on the roadbed. Since the abutment 100 has good rigidity, and the roadbed is generally a high-fill roadbed, which is prone to settlement, in some embodiments, a road roller can be used to compact the roadbed before laying the approach slab 200 to reduce the degree of settlement.
[0022] like Figure 1 As shown, the slab 200 has grouting holes, and the grouting holes are connected to steel pipes 400. The steel pipes 400 extend into the roadbed, and the pipe wall of the steel pipes 400 has grout outlet holes.
[0023] In this embodiment, grouting holes can be drilled on the slab 200 or reserved during the forming of the slab 200. The upper end of the steel pipe 400 is fixed and connected to the grouting hole, and the lower end of the steel pipe 400 is sealed and welded with a triangular pyramid to facilitate the lowering of the steel pipe 400 into the roadbed.
[0024] The lifting device 310 is pre-embedded in the roadbed and located below the second end of the ramp 200. The output end of the lifting device 310 is connected to the second end of the ramp 200 to drive the second end of the ramp 200 to rise and fall.
[0025] In this embodiment, the jacking device 310 is pre-embedded in the roadbed. After the bridgehead has been in operation for a period of time, the roadbed is further compacted by the vehicle load and settles. When the settlement rate drops to a preset value, the second end of the approach slab 200 is lifted to be flush with the bridge deck by driving the jacking device 310, and grout is injected through the grouting hole to fill the void, thereby repairing and reinforcing the bridgehead.
[0026] like Figure 3 As shown, in some embodiments of this application, the roadbed is further pre-embedded with a fixing plate 320, and the lifting device 310 is fixedly mounted on the fixing plate 320. In this embodiment, the fixing plate 320 increases the bearing capacity, reduces the descent of the lifting device 310 during the lifting of the slab 200, and ensures the stability of the lifting process.
[0027] like Figure 2 As shown, in some embodiments of this application, the slab 200 includes a conventional concrete section 210 and two self-stressing concrete sections 220. The two self-stressing concrete sections 220 are located at the first end and the second end of the slab 200, respectively, and are cast from self-stressing concrete. In this embodiment, the slab 200 adopts a structure combining the conventional concrete section 210 and the self-stressing concrete section 220. The self-stressing concrete section 220 can improve the crack resistance and compressive strength of the ends of the slab 200, ensure the connection stability at both ends of the slab 200, and improve the service life of the slab 200.
[0028] In some embodiments, the self-stressing concrete employs a composite modification system of HCSA expansive agent, steel fiber, and fly ash. An exemplary mix proportion is as follows: HCSA expansive agent dosage 10%~12%, steel fiber (aspect ratio 35~45, tensile strength ≥700MPa) volume content 0.5%~1.5%, fly ash content 20%, and water-cement ratio 0.3. This mix proportion enables the concrete to achieve a maximum self-stress of 3.16MPa, a 28-day compressive strength ≥69MPa, and a flexural strength ≥9.5MPa, meeting the standards for self-stressing concrete and the load-bearing requirements of the slab.
[0029] In some embodiments of this application, two sets of grouting holes are provided, one set near the first end of the approach slab 200 and the other set near the second end of the approach slab 200. In this embodiment, different grouts can be injected through the two sets of grouting holes respectively. Specifically, due to the presence of the abutment 100, the soil near and below the abutment 100 cannot be effectively compacted during the compaction process of the compaction machinery, resulting in significant settlement of this part of the soil under its own weight and consolidation, leading to an increase in the voids in the approach slab 200. Injecting micro-expansion cement grout can effectively fill the voids and further compact this part of the soil. Injecting reinforcing mud grout near the roadbed can fill the gaps caused by the lifting device 310 raising the approach slab 200 and reinforce the roadbed.
[0030] like Figure 2 As shown, in some embodiments of this application, two slabs 200 are arranged side by side, and self-stressing concrete is poured at the joint 230 of the two slabs 200 to seal the joint 230. In this embodiment, the structure of splicing two slabs 200 can reduce the volume of a single slab 200, facilitating production and transportation. On the construction site, by filling the joint 230 of the two slabs 200 with self-stressing concrete, the waterproofness and structural strength at the joint 230 are ensured.
[0031] like Figure 4 As shown, in some embodiments of this application, a support plate 600 extends along the joint 230 of the two approach slabs 200 to form the roadbed. The support plate 600 abuts against the two approach slabs 200, and a plurality of concrete columns 700 extending into the roadbed are fixedly connected to the support plate 600. In this embodiment, the support plate 600 ensures that the two approach slabs 200 are at the same height.
[0032] like Figure 5 As shown, in some embodiments of this application, a guide positioning member 500 is fixedly provided on the bridge abutment 100. The guide positioning member 500 has a guide groove 510. The first end of the approach plate 200 is formed with a limiting part that slides in the guide groove 510. The limiting parts of both approach plates 200 cooperate with the guide groove 510 to make the two approach plates 200 flush. In this embodiment, the limiting part of the first end of the approach plate 200 is engaged in the guide groove 510, so that the two approach plates 200 can be flush, improving the accuracy of the approach plate 200 splicing.
[0033] This application also provides a construction method for a prefabricated bridge abutment structure, including: Precast slabs; using standardized steel molds, ordinary concrete is mixed and poured, then cured for 14 days until the strength reaches 35MPa, then 220mm self-stressed concrete section is poured, with Φ16 longitudinal self-stressing tendons pre-embedded, and cured for 28 days until the self-stress value reaches 3.0MPa.
[0034] Pre-embed a jacking device 310 in the roadbed; clean the construction area, pre-embed an 80cm×80cm×2cm fixing plate 320 and install the jacking device 310, construct concrete piles and lay a 20cm graded crushed stone layer, and lay a double-layer polyethylene sliding layer and a 40mm fine-grained asphalt functional layer.
[0035] The prefabricated slab 200 is hoisted, and the first end of the slab 200 is connected to the bridge abutment 100, and the second end is connected to the output end of the jacking device 310. The slab 200 is hoisted at four points by a truck crane, and the limiting part of the first end of the slab 200 is inserted into the guide groove 510 for positioning and the positioning pin is inserted to lock it.
[0036] Drill grouting holes on the slab 200 and lower the steel pipe 400.
[0037] When the roadbed settlement rate drops to the preset value, the jacking device 310 jacks the approach slab 200 to be flush with the bridge deck and injects grout through the grouting hole to fill the void between the roadbed and the approach slab 200.
[0038] In this embodiment, after the ramp 200 is erected, it can be opened to traffic, allowing the roadbed to settle further naturally. When the settlement rate drops to a preset value, for example, when the rate is ≤0.5mm / d, the controller 330 controls the lifting device 310 to lift the second end of the ramp 200 to be flush with the bridge deck, and then injects grout through the grouting hole to fill the void and reinforce the roadbed.
[0039] In some embodiments of this application, the method for fabricating the slab 200 includes: first pouring a section of ordinary concrete 210, curing it to a predetermined strength, and then pouring self-stressing concrete sections 220 at both ends of the ordinary concrete section 210. In this embodiment, the slab 200 adopts a structure combining the ordinary concrete section 210 and the self-stressing concrete section 220. The self-stressing concrete section 220 can improve the crack resistance and compressive strength of the ends of the slab 200, ensure the stable connection at both ends of the slab 200, and improve the service life of the slab 200.
[0040] In some embodiments, the mix proportion of self-stressing concrete can be: P·O42.5 cement 449.9 kg / m³ 3 Grade 1 fly ash: 92.4 kg / m³ 3 HCSA expanding agent 65.1 kg / m 3 (12% admixture), steel fiber 78 kg / m 3 (1% volumetric admixture), natural aggregate 1669.5 kg / m³3 Water 186.2 kg / m 3 High-efficiency water-reducing agent 6.16kg / m³ 3 The self-stressing concrete for joints has a 90-day self-stress value of 4.2 MPa and an ultimate bond strength of 29.1 MPa.
[0041] In the embodiments of this application, the jacking device 310 is pre-embedded in the roadbed. After the bridgehead has been in operation for a period of time, the roadbed is further compacted by the vehicle load and settles. When the settlement rate drops to a preset value, the second end of the approach slab 200 is lifted to be flush with the bridge deck by driving the jacking device 310, and grout is injected through the grouting hole to fill the void, thereby achieving the repair and reinforcement of the bridgehead.
[0042] In some embodiments of this application, the method of injecting grout through grouting holes includes: injecting micro-expansion cement grout into the grouting hole near the abutment 100 and injecting reinforcing slurry into the grouting hole near the roadbed. Specifically, micro-expansion cement grout with an expansion rate of 1.5% is injected into the grouting hole on the abutment 100 side, and reinforcing slurry is injected into the roadbed side, with the pressure controlled at 0.3~0.5MPa. In some embodiments, ordinary cement grout may be used as the reinforcing slurry.
[0043] In this embodiment, due to the presence of the abutment 100, the soil near and below the abutment 100 cannot be effectively compacted during the compaction process of the compaction machinery. This results in significant settlement of this soil under its own weight and consolidation, leading to an increase in the voids in the approach slab 200. Injecting micro-expansion cement grout can effectively fill these voids. Furthermore, injecting reinforcing mud grout near the roadbed can fill the gaps created by the lifting device 310 raising the approach slab 200 and reinforce the roadbed.
[0044] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.
Claims
1. A prefabricated bridge abutment structure, characterized in that, include: The bridge abutment, roadbed, approach slab, and lifting device are provided. The approach slab is a precast slab, with its first end connected to the bridge abutment and its second end erected on the roadbed. The approach slab has grouting holes connected to steel pipes that extend into the roadbed and have grout outlet holes in their walls. The lifting device is embedded in the roadbed and located below the second end of the approach slab. The output end of the lifting device is connected to the second end of the approach slab to drive its lifting motion.
2. The prefabricated bridge abutment structure according to claim 1, characterized in that, The roadbed is also pre-embedded with a fixing plate, and the lifting device is fixedly mounted on the fixing plate.
3. The prefabricated bridge abutment structure according to claim 1, characterized in that, The approach slab includes a regular concrete section and two self-stressing concrete sections. The two self-stressing concrete sections are located at the first end and the second end of the approach slab, respectively. The self-stressing concrete sections are cast from self-stressing concrete.
4. The prefabricated bridge abutment structure according to claim 1, characterized in that, The grouting holes are provided in two sets, one set of which is close to the first end of the slab, and the other set of which is close to the second end of the slab.
5. A prefabricated bridge abutment structure according to claim 1, characterized in that, Two planks are arranged side by side, and self-stressing concrete is poured at the joint between the two planks to seal the joint.
6. A prefabricated bridge abutment structure according to claim 5, characterized in that, A support plate is provided along the joint of the two approach slabs on the roadbed. The support plate abuts against the two approach slabs and is fixed to a plurality of concrete columns extending into the roadbed.
7. A prefabricated bridge abutment structure according to claim 5, characterized in that, A guide positioning component is fixedly installed on the bridge platform. The guide positioning component has a guide groove. The first end of the approach plate is formed with a limiting part that slides in the guide groove. The limiting parts of both approach plates cooperate with the guide groove so that the two approach plates are flush.
8. A construction method for a prefabricated bridge abutment structure, characterized in that, include: Precast slabs; Pre-embed lifting devices within the roadbed; The prefabricated slabs are hoisted, and the first end of the slab is connected to the bridge abutment, while the second end is connected to the output end of the jacking device. Drill grouting holes in the slab and lower steel pipes; When the roadbed settlement rate drops to the preset value, the jacking device lifts the approach slab to be flush with the bridge deck and injects grout through the grouting hole to fill the gap between the roadbed and the approach slab.
9. A construction method for a prefabricated bridge abutment structure according to claim 8, characterized in that, The method for making the slab includes: first pouring a section of ordinary concrete, curing it to the predetermined strength, and then pouring self-stressed concrete sections at both ends of the ordinary concrete section.
10. A construction method for a prefabricated bridge abutment structure according to claim 8, characterized in that, Methods of injecting grout through grouting holes include: injecting micro-expansion cement grout into grouting holes near the abutment and injecting reinforcing mud into grouting holes near the roadbed.