Novel settlement-reducing composite bridge abutment structure for soft soil area

Abstract

The utility model relates to the technical field of bridge abutments, in particular to a novel subsidence reduction composite bridge abutment structure for a soft soil area, which comprises an original filling soil embankment soft body, a prefabricated panel is built on the periphery of the original filling soil embankment soft body, and a transition area is formed between the bottom of the prefabricated panel and the bottom of the original filling soil embankment soft body. A first drainage cushion layer is laid on the surface of the transition area, the original filling embankment soft body, the prefabricated panel and the first drainage cushion layer are matched to form a first filling area, light foam concrete is poured in the first filling area, the semi-rigid cast-in-place light foam concrete is adopted as a bridge abutment lower foundation, a reinforced cushion soil layer and a bridge abutment rigid foundation are combined, and the bridge abutment lower foundation and the bridge abutment rigid foundation are combined. The additional stress on the weak underlying foundation of the bridge abutment is effectively reduced, and the settlement deformation is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of bridge abutments, in particular to a novel subsidence-reducing composite bridge abutment structure for soft soil areas. Background Art

[0002] With the increasing demand for transportation, the use of bridges and culverts to cross or underpass existing roads, farmland, lakes and other construction sites is becoming increasingly popular. The number of road-bridge transition sections such as bridgeheads and bridgebacks is also increasing.

[0003] There is a large difference in stiffness between the abutment and the bridge structure. When crossing soft soil areas such as lakes and farmland, the foundation bearing capacity and deformation stiffness are low. Under the action of long-term vehicle loads, large differential settlement is prone to occur, resulting in the phenomenon of bridge head jumping, affecting road riding comfort and driving safety. In the existing technical specification system, there are three main ways to address the bridge head jumping phenomenon: backfill with low-compressibility soil such as gravel and crushed stone; use lightweight foam materials; use reinforced fill;

[0004] When using traditional gravel and crushed stone for backfilling, the narrow working surface of the abutment makes it difficult to effectively compact the filler, and the bridge head vehicle jumping phenomenon cannot be effectively alleviated;

[0005] The method of using reinforced fill and multiple modules to form an earthquake-resistant wall fully utilizes the flexible energy absorption characteristics of reinforced soil to resist vibration loads. Compared with traditional solutions, it can save slope land and reduce retaining wall costs. However, in actual construction, it is still inevitable to compact the reinforced soil layer by layer, which is difficult to construct and has a heavy deadweight. In soft soil areas, the fill generates significant additional stress on the underlying soft soil layer at the bottom of the abutment. During subsequent use, the consolidation creep of the lower soil often causes large-scale bulging deformation in the middle and lower parts, creating secondary safety hazards.

[0006] When lightweight foam concrete is used as the backfill material for bridges, it is a porous and brittle material that comes into direct contact with rigid components such as bridge pedestals, beams and slabs, and structural layers. The vibration load from vehicles passing through can cause stress concentration on the contact surface, inducing cracking or voiding of the contact surface. This can easily lead to rainwater infiltration, affecting the overall strength and increasing the risk of water damage under heavy rainfall conditions.

[0007] In view of the above-mentioned defects, the inventors of the present invention have obtained the present invention after a long period of research and practice. Utility Model Content

[0008] In order to solve the technical problems existing in the above-mentioned prior art, the utility model provides a novel settlement-reducing composite abutment structure for use in soft soil areas.

[0009] To achieve the above-mentioned objectives, the present invention provides the following technical solutions: a new type of settlement-reducing composite abutment structure for soft soil areas, comprising an original fill embankment, a prefabricated panel built around the periphery of the original fill embankment, a transition zone formed between the bottom of the prefabricated panel and the original fill embankment, a first drainage cushion layer paved on the surface of the transition zone, the original fill embankment, the prefabricated panel and the first drainage cushion layer cooperate to form a first filling area, lightweight foam concrete is poured in the first filling area, a second drainage cushion layer is paved on the top of the lightweight foam concrete, the second drainage cushion layer and the prefabricated panel cooperate to form a second filling area, a reinforced cushion layer is paved in the second filling area, a bridge head pillow beam is provided on one side of the reinforced cushion layer, a toe block is provided between the bridge head pillow beam and the prefabricated panel, and the toe block is connected to the prefabricated panel.

[0010] Preferably, the surface of the original fill embankment is modified to have multiple stepped platforms, and each stepped platform is provided with a reverse slope of 1%-2%.

[0011] Preferably, a drainage ditch is opened at the end of each step platform, the drainage ditch is paved with graded gravel, and drainage pipes are buried at both ends of each group of drainage ditch.

[0012] Preferably, the drain pipe is designed as a one-way opening, one side of the closed end of the drain pipe is buried in the drainage ditch, the length of the portion of the drain pipe buried in the drainage ditch is not less than 50 cm, and several groups of through holes for drainage are opened on the surface of the drain pipe.

[0013] Preferably, the thickness of the first drainage cushion layer and the second drainage cushion layer are both not less than 15 cm, and an anti-permeability geomembrane is laid between the lightweight foam concrete and the first drainage cushion layer and between the lightweight foam concrete and the second drainage cushion layer.

[0014] Preferably, a group of wire mesh is buried at the upper and lower ends of the lightweight foam concrete respectively, the distance between the group of wire mesh located at the upper end of the lightweight foam concrete and the top surface of the lightweight foam concrete is 50-100 cm, and the distance between the other group of wire mesh located at the lower end of the lightweight foam concrete and the bottom surface of the lightweight foam concrete is 50-100 cm.

[0015] Preferably, the reinforced cushion layer includes cushion soil and reinforcement bars, the cushion soil is laid in the second filling area, and the reinforcement bars are provided in several groups, and the several groups of reinforcement bar layers are stacked in sequence in the cushion soil, and the distance between two adjacent groups of reinforcement bars is 40-80 cm.

[0016] Preferably, the bridge head bolster is of I-shaped design, the bottom of the bridge head bolster is buried in the reinforced cushion soil layer, one side of the bridge head bolster is in conflict with the reinforced cushion soil layer, and the other side of the bridge head bolster is in conflict with the foot guard block.

[0017] Preferably, a drainage ditch is provided on the outside of the prefabricated panel, the drainage ditch surrounds the outside of the prefabricated panel, and the end of the drainage pipe extends to the top of the drainage ditch.

[0018] Compared with the prior art, the beneficial effects of the present invention are:

[0019] 1. In this utility model, semi-rigid cast-in-place lightweight foam concrete is used as the lower foundation of the abutment, combined with a reinforced cushion layer and a rigid foundation of the abutment, which effectively reduces the additional stress on the weak underlying foundation of the abutment and reduces settlement deformation;

[0020] 2. The lightweight foam concrete casting has its own bearing capacity. After reaching the required strength, it can be used as a working platform to create favorable conditions for the rolling and paving of the upper reinforced cushion layer. The reinforced fill has stronger deformation coordination ability and greater flexibility. When paved between the road surface and bridge abutments and the lightweight soil, it can buffer the dynamic load of vehicles on the road surface and reduce the cracking of the lightweight soil when it directly bears the dynamic load of vehicles.

[0021] 3. In the present invention, the bridge head support beam is used to transmit the road surface load, which has a high degree of prefabrication and is convenient for construction and maintenance. A flexible reinforced cushion layer is laid behind the bridge head support beam wall and between it and the lightweight foam concrete, which can give full play to the stress diffusion and deformation coordination effect of the reinforced fill, avoid stress concentration between rigid components, and control cracking.

[0022] 4. In the present invention, both the lightweight foam concrete and the reinforced cushion soil layer can be laid vertically, thus avoiding slope under the bridge, improving the utilization rate of the space under the bridge, reducing the span of the bridge, and effectively reducing the overall cost of the project. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic front cross-sectional view of the subsidence-reducing composite abutment structure of the utility model;

[0024] Figure 2 This is a side cross-sectional diagram of the subsidence reduction composite abutment structure in this utility model. Figure 1 ;

[0025] Figure 3 This is a side cross-sectional diagram of the subsidence reduction composite abutment structure in this utility model. Figure 2 ;

[0026] Figure 4 This is a schematic diagram of the three-dimensional structure of the bridge head support beam in the utility model;

[0027] Figure 5 This is a schematic diagram of the three-dimensional structure of the drainage pipe in the utility model;

[0028] Figure 6 This is a schematic diagram of the use status of the settlement-reducing composite abutment in the utility model.

[0029] The numbers in the figure represent:

[0030] 1. Original fill embankment; 2. Precast panels; 3. First drainage cushion layer; 4. Lightweight foam concrete; 5. Second drainage cushion layer; 6. Reinforced cushion layer; 61. Pad soil; 62. Reinforcement; 7. Bridge head support beam; 8. Foot guard block; 9. Drainage ditch; 10. Drainage pipe; 11. Anti-permeability geomembrane; 12. Wire mesh; 13. Drainage ditch. DETAILED DESCRIPTION

[0031] The following further illustrates the above and other technical features and advantages of the present invention in conjunction with the accompanying drawings and embodiments. However, the following embodiments are merely preferred embodiments of the present invention and are not exhaustive.

[0032] Example:

[0033] like Figure 1 - Figure 6 As shown, the utility model provides a new type of subsidence reduction composite abutment structure for soft soil areas, including an original fill embankment 1, the surface of the original fill embankment 1 is repaired with a multi-step platform, the multi-step platform can provide hierarchical support, better withstand the pressure transmitted vertically downward, each step platform is provided with a 1%-2% reverse slope, the setting of the reverse slope can enable the step platform to guide the infiltrating rainwater and concentrate the rainwater, the end of the multi-step platform on the surface of the original fill embankment 1 is provided with a drainage ditch 9, the ditch is paved with graded Gravel, the drainage ditch 9 is used to guide the concentrated water. Under the guidance of the drainage ditch 9, the concentrated water flows horizontally along the drainage ditch 9. Drain pipes 10 are buried at both ends of each group of drainage ditch 9. The drainage pipes 10 are designed to be one-way open. One side of the closed end of the drainage pipe 10 is buried in the ditch. Several groups of through holes for drainage are opened on the surface. The length of the buried ditch is not less than 50 cm. The water moving horizontally inside the drainage ditch 9 enters the drainage pipe 10 through the through holes opened on the surface of the drainage pipe 10 and is discharged through the drainage pipe 10;

[0034] A prefabricated panel 2 is built around the original fill embankment soft 1, and a transition zone is formed between the bottom of the prefabricated panel 2 and the bottom of the original fill embankment soft 1. The surface of the transition zone is paved with a first drainage cushion layer 3. The original fill embankment soft 1, the prefabricated panel 2 and the first drainage cushion layer 3 cooperate to form a first filling area. Lightweight foam concrete 4 is poured in the first filling area. An anti-permeability geomembrane 11 is laid between the lightweight foam concrete 4 and the first drainage cushion layer 3 and between the lightweight foam concrete 4 and the second drainage cushion layer 5. The anti-permeability geomembrane 11 can slow down the reverse infiltration of water through the first drainage cushion layer 3 and the second drainage cushion layer 5 into the lightweight foam concrete 4;

[0035] A set of wire meshes 12 are buried at the upper and lower ends of the lightweight foam concrete 4. The wire mesh 12 at the upper end of the lightweight foam concrete 4 is 50-100 cm away from the top surface of the lightweight foam concrete 4, and the wire mesh 12 at the lower end of the lightweight foam concrete 4 is 50-100 cm away from the bottom surface of the lightweight foam concrete 4.

[0036] A second drainage cushion layer 5 is laid on top of the lightweight foam concrete 4. The second drainage cushion layer 5 cooperates with the prefabricated panel 2 to form a second filling area. A reinforced cushion layer 6 is laid in the second filling area. The reinforced cushion layer 6 includes cushion 61 and reinforcement ribs 62. The cushion 61 is laid in the second filling area. The reinforcement ribs 62 are provided in several groups. The groups of reinforcement ribs 62 are stacked and arranged in the cushion 61. The spacing between two adjacent groups of reinforcement ribs 62 is 40-80 cm. The laid reinforcement ribs 62 can improve the overall structural strength and compressive capacity of the cushion 61, thereby providing better support capacity.

[0037] A bridge head support beam 7 is provided on one side of the reinforced cushion layer 6. The bridge head support beam 7 is an I-shaped design. The bottom of the bridge head support beam 7 is buried in the reinforced cushion layer 6. One side of the bridge head support beam 7 is in contact with the reinforced cushion layer 6. The reinforced cushion layer 6 in contact with the bridge head support beam 7 can play a role in pressing down and fixing the bridge head support beam 7. At the same time, the pressure on the bridge head support beam 7 will be evenly transmitted to the reinforced cushion layer 6, ensuring uniformity and consistency of force.

[0038] A foot stopper 8 is provided between the bridge head bolster 7 and the prefabricated panel 2. The foot stopper 8 is connected to the prefabricated panel 2. The other side of the bridge head bolster 7 abuts against the foot stopper 8. The foot stopper 8 assists the reinforced cushion layer 6 to limit the bridge head bolster 7 from the other direction, so that the bridge head bolster 7 is stably maintained in the set position.

[0039] A drainage ditch 13 is provided on the outside of the prefabricated panel 2. The drainage ditch 13 surrounds the outside of the prefabricated panel 2. The end of the drain pipe 10 extends to the top of the drainage ditch 13. The water discharged through the drain pipe 10 will directly enter the drainage ditch 13. The water entering the drainage ditch 13 is discharged along the drainage ditch 13, avoiding water remaining around the original fill embankment 1 and the prefabricated panel 2.

[0040] The above description is merely a preferred embodiment of the present invention and is intended to be illustrative rather than restrictive of the present invention. Those skilled in the art will appreciate that many changes, modifications, and even equivalents may be made to the present invention within the spirit and scope of the claims, and all of these changes will fall within the scope of protection of the present invention.

Claims

1. A new type of settlement reduction composite abutment structure for soft soil areas, characterized by: It includes an original fill embankment, and prefabricated panels are built around the periphery of the original fill embankment. A transition zone is formed between the bottom of the prefabricated panels and the original fill embankment. The surface of the transition zone is paved with a first drainage cushion layer. The original fill embankment, prefabricated panels and the first drainage cushion layer cooperate to form a first filling area. Lightweight foam concrete is poured in the first filling area. A second drainage cushion layer is laid on the top of the lightweight foam concrete. The second drainage cushion layer and the prefabricated panels cooperate to form a second filling area. A reinforced cushion layer is laid in the second filling area. A bridge head pillow beam is provided on one side of the reinforced cushion layer. A toe block is provided between the bridge head pillow beam and the prefabricated panel, and the toe block is connected to the prefabricated panel.

2. The novel settlement reducing composite abutment structure for soft soil areas according to claim 1, characterized in that: The surface of the original fill embankment is modified to have multiple stepped platforms, and each stepped platform is provided with a counter-inclination slope of 1% to 2%.

3. The novel settlement reducing composite abutment structure for soft soil areas according to claim 2, characterized in that: A drainage ditch is provided at the end of each step platform, and the drainage ditch is filled with graded gravel. Drainage pipes are buried at both ends of each group of drainage ditch.

4. The novel settlement reducing composite abutment structure for soft soil areas according to claim 3, characterized in that: The drainage pipe is designed as a one-way opening, and one side of the closed end of the drainage pipe is buried in the drainage ditch. The length of the portion of the drainage pipe buried in the drainage ditch is not less than 50 cm. Several groups of through holes for drainage are opened on the surface of the drainage pipe.

5. The novel settlement reducing composite abutment structure for soft soil areas according to claim 3, characterized in that: The thickness of the first drainage cushion layer and the second drainage cushion layer are both not less than 15 cm, and an anti-permeability geomembrane is laid between the lightweight foam concrete and the first drainage cushion layer, and between the lightweight foam concrete and the second drainage cushion layer.

6. The novel settlement reducing composite abutment structure for soft soil areas according to claim 1, characterized in that: A group of wire mesh is buried at the upper and lower ends of the lightweight foam concrete respectively. The distance between the group of wire mesh located at the upper end of the lightweight foam concrete and the top surface of the lightweight foam concrete is 50-100 cm, and the distance between the other group of wire mesh located at the lower end of the lightweight foam concrete and the bottom surface of the lightweight foam concrete is 50-100 cm.

7. The novel settlement reducing composite abutment structure for soft soil areas according to claim 1, characterized in that: The reinforced cushion layer includes cushion soil and reinforcement bars. The cushion soil is laid in the second filling area. The reinforcement bars are arranged in several groups. Several groups of reinforcement bar layers are stacked in sequence in the cushion soil. The distance between two adjacent groups of reinforcement bars is 40-80 cm.

8. The novel settlement reducing composite abutment structure for soft soil areas according to claim 1, characterized in that: The bridge head support beam is of I-shaped design, the bottom of the bridge head support beam is buried in the reinforced cushion soil layer, one side of the bridge head support beam is in conflict with the reinforced cushion soil layer, and the other side of the bridge head support beam is in conflict with the foot guard block.

9. A novel settlement reducing composite abutment structure for soft soil areas according to claim 1 or 4, characterized in that: A drainage ditch is provided on the outside of the prefabricated panel, and the drainage ditch surrounds the outside of the prefabricated panel. The end of the drainage pipe extends to the top of the drainage ditch.

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