A prefabricated articulated bridge head slab and bridge head structure suitable for deep soft soil foundation and a construction method thereof

Abstract

The present invention discloses a prefabricated hinged bridgehead slab and bridgehead structure suitable for deep soft soil foundation and a construction method thereof, wherein the bridgehead slab is formed by horizontally assembling and connecting a plurality of prefabricated blocks, and elastic sealing pads are embedded between adjacent prefabricated blocks; prefabricated grooves for connection are provided on the prefabricated blocks, and fasteners pass through the prefabricated grooves horizontally to connect adjacent prefabricated blocks, and springs are provided in the prefabricated grooves of adjacent prefabricated blocks, and the springs are sleeved at both ends of the fasteners; an arc groove is provided at the bottom of the bridgehead slab, and an embedded part is provided on the corbel of the abutment, and a semicircular part adapted to the arc groove is provided at the upper end of the embedded part, and the semicircular part is fixedly engaged with the arc groove; embedded holes are provided on both sides of the bridgehead slab near the abutment end, and spring bolts for connecting the bridgehead slab and the abutment are provided in the embedded holes. The present invention can effectively alleviate the settlement problem of the foundation, solve the problem of vehicle jumping at the highway bridgehead on the deep soft soil foundation, and has simple construction and remarkable effect.

Description

Technical Field

[0001] The invention relates to a bridgehead slab and a bridgehead structure and a construction method thereof, and in particular to a prefabricated hinged bridgehead slab and a bridgehead structure suitable for thick soft soil foundation and a construction method thereof. Background Art

[0002] Bridge jumping refers to the deformation, fracture, or even potholes of the road surface or slab at the junction of the road and the bridge abutment, which causes vehicles to jump and bump after being impacted by the area. With the increasing traffic volume, bridge jumping is becoming more and more common on highways at all levels. The bumps caused by the jumping not only cause discomfort to the occupants, but may even cause the vehicle to lose control, posing a threat to safety and seriously affecting road traffic safety. Although the majority of highway practitioners have worked hard to solve this problem from design to construction, the bridge jumping problem has never been well solved.

[0003] The bridgehead slab is one of the effective solutions to bridgehead jumping. It is placed between the end of the abutment or cantilever beam and the fill to prevent the settlement of the bridge end connection part. It can play a buffering role when the vehicle is driving and has been widely used. However, the effect of the existing technology is not ideal. The splicing treatment methods of the bridgehead slab and the abutment are different, which is easy to produce excessive stress, resulting in secondary jumping, slab sliding, and damage to the abutment. Especially in deep soft soil foundations, due to poor geological conditions, soil settlement is more serious. The stress of conventional integral bridgehead slabs is more complicated and cannot solve the bridgehead jumping problem well. Therefore, it is necessary to continuously explore new and effective solutions. Summary of the invention

[0004] Purpose of the invention: In view of the problems existing in the prior art, one of the purposes of the present invention is to provide a prefabricated articulated bridgehead cladding suitable for deep soft soil foundations, which is easy to install and has significant effects; the second purpose of the present invention is to provide a bridgehead structure that can effectively solve the problem of vehicle jumping at a highway bridgehead caused by the complex stress of conventional cladding on deep soft soil foundations; the third purpose of the present invention is to provide a construction method for a bridgehead cladding.

[0005] Technical solution: The prefabricated hinged bridgehead slab structure of the present invention is suitable for deep soft soil foundation. The bridgehead slab is formed by a plurality of prefabricated blocks assembled and connected horizontally, and elastic sealing pads are embedded between adjacent prefabricated blocks; prefabricated grooves for connection are provided on the prefabricated blocks, and fasteners pass through the prefabricated grooves horizontally to connect adjacent prefabricated blocks. Springs are provided in the prefabricated grooves of adjacent prefabricated blocks, and the springs are sleeved at both ends of the fasteners, so that one end of the spring abuts against the side wall of the prefabricated groove and the other end abuts against the fasteners. The fasteners can be bolt and nut combinations commonly used in engineering.

[0006] The prefabricated grooves on the prefabricated blocks are arranged on both sides of adjacent prefabricated blocks, and the same number is arranged on each side for easy connection; the elastic sealing pads between adjacent prefabricated blocks act as buffers, and the prefabricated blocks can be prefabricated using reinforced concrete structures in the prior art, and the specific specifications are determined according to actual construction needs; the prefabricated grooves are arranged above the abutment slabs, and after the assembly is completed, the prefabricated grooves are sealed with elastic sealing pads to improve durability. The prefabricated grooves are arranged above the abutment slabs to save processes. If they are arranged below, a step of flipping the bridge head slab is required after the assembly is completed.

[0007] Preferably, the bridgehead scaffolding is formed by connecting four prefabricated blocks, and the prefabricated blocks are symmetrically distributed along the transverse center line and the longitudinal center line of the bridgehead scaffolding, that is, each prefabricated block is connected to its two adjacent prefabricated blocks; four prefabricated panels are selected for assembly, each prefabricated block in the scaffolding is better stressed, and a certain deformation is allowed between the prefabricated blocks on both sides of the connecting surface; while two scaffolding panels assembled or a single scaffolding panel belongs to an overall rigid structure, and due to the settlement of the roadbed, cracks are easily generated in the middle of the scaffolding, affecting its service life.

[0008] A bridgehead structure of the present invention includes an abutment, a bridgehead slat is provided on the corbel of the abutment, and the bridgehead slat is the above-mentioned prefabricated hinged bridgehead slat suitable for thick soft soil foundation; an arc groove is provided at the bottom of the bridgehead slat, and an embedded part is provided on the corbel of the abutment, and a semicircular part adapted to the arc groove is provided at the upper end of the embedded part, and the semicircular part is fixedly engaged with the arc groove; both sides of the bridgehead slat near the abutment end are provided with embedded holes, and both sides of the bridgehead slat near the abutment end are provided with embedded holes, and spring bolts for connecting the bridgehead slat and the abutment are provided in the embedded holes. The embedded holes can be arranged horizontally.

[0009] Preferably, the bridgehead structure also includes a roadbed fill located below the abutment slab, a crushed stone cushion layer provided between the roadbed fill and the bridgehead slab, a road surface layer provided above the bridgehead slab, and nail-shaped mixing piles located below the bridgehead slab. The nail-shaped mixing piles are driven into the roadbed fill to alleviate the problem of vehicle jumping at the bridgehead caused by the settlement of the bridgehead slab. The use of crushed stone filling between the roadbed fill and the bridgehead slab can reduce the settlement of the abutment back.

[0010] Preferably, the embedded part further includes a support portion located below the semicircular portion, the support portion includes an embedded corbel portion and an exposed portion, and the exposed portion is sleeved with a rubber pad. The provision of the rubber pad can play a buffering role between the bridge head slat and the corbel and facilitate the rotation of the slat. The support portion of the embedded part is cylindrical, which is convenient for prefabrication.

[0011] Preferably, the semicircular portion of the embedded component is wrapped with rubber. The provision of rubber can reduce the wear of the embedded component and extend the service life of the embedded component.

[0012] Preferably, the embedded hole is in a square shape to facilitate construction by workers; if an irregular hole is used, the construction workload will increase.

[0013] Preferably, the height of the embedded hole is 10 to 13 times the diameter of the spring bolt, so that the strapping plate has enough rotation space.

[0014] The present invention also provides a construction method for the above bridge head structure, which comprises the following steps:

[0015] Abutment construction: After the abutment construction is completed, embedded parts are buried on the abutment's corbels, the roadbed behind the abutment is filled with soil, nail-shaped mixing piles are driven into the roadbed soil, a crushed stone cushion is laid on the top of the roadbed soil, and the bridgehead slab is installed above the crushed stone cushion; finally, the road surface layer is laid;

[0016] The installation process of the bridgehead slab includes the assembly and field installation of the bridgehead slab, wherein the assembly method of the bridgehead slab is as follows: fasteners are placed in prefabricated grooves of prefabricated blocks, springs are respectively sleeved at both ends of the fasteners, elastic sealing pads are embedded between the prefabricated blocks, and the prefabricated blocks are horizontally connected by fasteners, thereby assembling the bridgehead slab;

[0017] The installation method of the bridgehead cladding is as follows: align and engage the arc groove of the assembled bridgehead cladding with the semicircular part of the embedded part, place the spring bolt in the embedded hole, and connect the bridgehead cladding and the abutment.

[0018] Beneficial effects: Compared with the existing technology,

[0019] (1) The nail-shaped mixing piles driven into the roadbed fill in the present invention can effectively reduce the settlement caused by the upper load by utilizing the engagement between the nail-shaped mixing piles and the soil, thereby solving the problem of large settlement in the later stage caused by insufficient compaction due to the limitation of mechanical equipment at the back of the platform;

[0020] (2) The bridgehead slab of the present invention adopts a hinged connection, which has the ability of unidirectional deformation, can adapt to the long-term settlement characteristics of soft soil foundation, and alleviate the settlement difference between the transition abutment and the roadbed;

[0021] (3) The connection of the slab near the abutment end can ensure that the slab can rotate freely with the settlement of the roadbed, effectively protecting the abutment from damage;

[0022] (4) The present invention can effectively alleviate the settlement problem of the foundation and solve the problem of vehicle jumping at the highway bridge head on a deep soft soil foundation. The construction is simple and the effect is remarkable. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the bridgehead structure of the present invention;

[0024] Figure 2 is a top view of the bridgehead slab of the present invention;

[0025] Figure 3 yes Figure 2 AA surface section view;

[0026] Figure 4 It is a structural diagram of embedded parts. DETAILED DESCRIPTION

[0027] The present invention is further described in detail below with reference to the embodiments.

[0028] like Figure 1 The figure shows an overall schematic diagram of the bridge head structure, which includes an abutment 12, a carriageway slab 1 is installed on the left side of the abutment 12, a corbel 2 is provided on the right side of the abutment 12, a transverse gap is left between the corbel 2 and the bridge head cladding 10, and space is reserved for the rotation of the cladding; to the right of the abutment 12, from bottom to top, are the roadbed fill 11, the gravel cushion layer 18, the bridge head cladding 10, and the road surface layer 9; wherein, the upper surface of the roadbed fill 11 is flush with the upper surface of the corbel 2, and a nail-shaped mixing pile 8 is provided directly below the bridge head cladding 10, the nail-shaped mixing pile 8 is driven into the roadbed fill 11, and the top surface of the nail-shaped mixing pile 8 is flush with the upper surface of the roadbed fill 11.

[0029] The bridgehead slab 10 is a prefabricated hinged bridgehead slab suitable for thick soft soil foundation, such as Figure 2 As shown, it is formed by four square prefabricated blocks horizontally assembled and connected. The prefabricated blocks are prefabricated with reinforced concrete structures and are divided into a first prefabricated block 10-1, a second prefabricated block 10-2, a third prefabricated block 10-3, and a fourth prefabricated block 10-4. The first prefabricated block 10-1 is located at the upper left of the bridgehead slab 10, the second prefabricated block 10-2 is located at the upper right of the bridgehead slab 10, the third prefabricated block 10-3 is located at the lower left of the bridgehead slab 10, and the fourth prefabricated block 10-4 is located at the lower right of the bridgehead slab 10. The four prefabricated blocks are arranged along the bridgehead slab. The transverse centerline and the longitudinal centerline of the plate 10 are symmetrically distributed; the right side of the first prefabricated block 10-1 is connected to the left side of the second prefabricated block 10-2, and two prefabricated grooves 13 corresponding to the positions are provided on both. The lower end of the first prefabricated block 10-1 is connected to the upper end of the third prefabricated block 10-3, and two prefabricated grooves 13 corresponding to the positions are provided on both. The connection and the opening of the prefabricated grooves of other prefabricated blocks are similar. Each prefabricated block is connected to the two adjacent prefabricated blocks, and four prefabricated grooves 13 are provided on the top of each prefabricated block. The connection between adjacent prefabricated blocks is as follows: Figure 3As shown, taking the connection between the third prefabricated block 10-3 and the fourth prefabricated block 10-4 as an example, a spring 16 is put on the bolt 17, and then it passes horizontally through the prefabricated groove of the fourth prefabricated block 10-4 and the prefabricated groove of the third prefabricated block 10-3, and then another spring 16 is put on, and finally the bolt cap is screwed on, so that one end of the spring 16 is against the side wall of the prefabricated groove, and the other end is against the bolt head or the bolt cap; and elastic sealing gaskets 15 are provided between adjacent prefabricated blocks to act as a buffer. After assembly, the prefabricated groove is sealed with an elastic sealing gasket to improve durability; the connection method between other prefabricated blocks is the same.

[0030] The embedded part 5 is embedded in the corbel 2 of the abutment 12. The embedded part 5 includes a semicircular part 19 and a supporting part 20. The semicircular part 19 is located at the upper end of the embedded part 5. The semicircular part 19 is wrapped with rubber to reduce friction and increase the service life of the embedded part 5. The supporting part 20 is located below the semicircular part 19. The overall shape of the supporting part 20 is cylindrical, which includes an embedded corbel part and an exposed part. The exposed part is covered with a rubber pad 7. The setting of the rubber pad 7 can play a buffering role between the bridge head slab 10 and the corbel 2 and facilitate the rotation of the slab. The thickness of the crushed stone cushion layer 18 is the same as the height of the exposed part of the supporting part of the embedded part 5. The bridge head slab 10 and the roadbed fill 11 are filled with crushed stones to reduce the settlement of the abutment back.

[0031] One end of the bridge plank 10 is placed on the corbel 2, and an arc groove 6 is provided at the bottom of the bridge plank 10. The position of the arc groove 6 corresponds to the position of the embedded part 5, and the semicircular part 19 is adapted to the arc groove 6, and the semicircular part 19 is fixed with the arc groove 6 to facilitate the rotation of the bridge plank 10; both sides of the bridge plank 10 close to the abutment end are transversely provided with embedded holes 4, and the embedded holes 4 are provided with spring bolts 3 for connecting the bridge plank 10 and the abutment 12. For the convenience of construction, the embedded holes 4 are square in shape, and the height of the embedded holes is 10 times the diameter of the spring bolts, so that the plank has enough rotation space; the spring bolts 3 are transversely arranged in the embedded holes 4, the rear end of the spring bolts 3 abuts against the side wall of the embedded holes 4, and the front end passes through the end of the bridge plank 10 and extends into the abutment 12, thereby connecting the abutment 12 and the bridge plank 10.

[0032] The construction method of the bridge head structure of the present embodiment is as follows: firstly, the abutment 12 is constructed; after the abutment 12 is constructed, the embedded parts 5 are embedded on the corbels 2 of the abutment 12, the roadbed fill 11 behind the abutment 12 is filled, the nail-shaped mixing piles 8 are driven into the roadbed fill 11, a crushed stone cushion layer 18 is laid on the upper part of the roadbed fill 11, and a bridge head slat 10 is installed above the crushed stone cushion layer 18; wherein, when the bridge head slat 10 is spliced, four prefabricated blocks are connected horizontally, bolts 17 are placed in prefabricated grooves 13, springs 16 are set at both ends, bolt caps 14 are screwed on and connected and fixed, elastic sealing pads 15 are embedded between the prefabricated blocks for buffering, and the bridge head slat 10 is assembled; then the arc groove 6 on the bridge head slat 10 is aligned and engaged with the semicircular part 19 of the embedded parts 5, spring bolts 3 are installed in the embedded holes 4, and the bridge head slat 10 and the abutment 12 are connected; finally, the road surface layer 9 is paved.

[0033] During the actual service of the bridge head structure of this embodiment, the nail-shaped mixing piles 8 can utilize the engagement between them and the soil to effectively reduce the settlement caused by the upper load, thereby solving the problem of large settlement in the later period caused by insufficient compaction due to the limitation of mechanical equipment at the back of the abutment; the bridge head cladding 10 adopts a hinged connection and has the ability of unidirectional deformation, which can adapt to the long-term settlement characteristics of soft soil foundation and alleviate the settlement difference between the transition abutment 12 and the roadbed; the connection design of the bridge head cladding 10 close to the abutment end is connected to the embedded parts 5 on the abutment corbel 2 through the arc groove 6, and is connected to the main body of the abutment 12 through the spring bolts 3, which can ensure that the cladding 10 can rotate freely with the settlement of the roadbed and effectively protect the abutment 12 from damage.

Claims

1. A bridge head structure, comprising a bridge abutment, characterized in that: A bridgehead slat is provided on the corbel of the abutment, and the bridgehead slat is a prefabricated hinged bridgehead slat suitable for deep soft soil foundation; the bridgehead slat is formed by a number of prefabricated blocks assembled and connected horizontally, and elastic sealing pads are embedded between adjacent prefabricated blocks; prefabricated grooves for connection are provided on the prefabricated blocks, and fasteners pass through the prefabricated grooves horizontally to connect adjacent prefabricated blocks, and springs are provided in the prefabricated grooves of adjacent prefabricated blocks, and the springs are sleeved at both ends of the fasteners, so that one end of the spring abuts against the side wall of the prefabricated groove and the other end abuts against the fastener; an arc groove is provided at the bottom of the bridgehead slat, and an embedded part is provided on the corbel of the abutment, and a semicircular part adapted to the arc groove is provided at the upper end of the embedded part , the semicircular part is fixed with the arc groove; both sides of the bridgehead trestle near the abutment end are provided with embedded holes, and spring bolts for connecting the bridgehead trestle and the abutment are arranged in the embedded holes; the height of the embedded holes is 10 to 13 times the diameter of the spring bolts; the bridgehead structure also includes the roadbed fill located below the abutment trestle, the gravel cushion layer arranged between the roadbed fill and the bridgehead trestle, the road surface layer arranged above the bridgehead trestle, and the nail-shaped mixing piles located below the bridgehead trestle, and the nail-shaped mixing piles are driven into the roadbed fill; the embedded part also includes a supporting part located below the semicircular part, the supporting part includes an embedded corbel part and an exposed part, and the exposed part is covered with a rubber pad.

2. The bridgehead structure according to claim 1, characterized in that: The bridgehead slab is formed by connecting four prefabricated blocks, and the prefabricated blocks are symmetrically distributed along the transverse center line and the longitudinal center line of the bridgehead slab.

3. The bridgehead structure according to claim 1, characterized in that: The semicircular portion of the embedded part is wrapped with rubber.

4. The bridgehead structure according to claim 1, characterized in that: The embedded hole is in a square shape.

5. A construction method for the bridge head structure according to claim 1, characterized in that The method comprises the following steps: bridge abutment construction; after the bridge abutment construction is completed, embedded parts are embedded on the brackets of the bridge abutment, the roadbed backfill behind the bridge abutment is filled, nail-shaped mixing piles are driven into the roadbed backfill, a crushed stone cushion layer is laid on the upper part of the roadbed backfill, and a bridge head slab is installed above the crushed stone cushion layer; Then lay the road surface layer; The installation of the bridgehead cladding includes: placing fasteners in prefabricated grooves of prefabricated blocks, arranging springs at both ends of the fasteners, embedding elastic sealing gaskets between the prefabricated blocks, and connecting the prefabricated blocks horizontally through fasteners; aligning and engaging the arc groove of the assembled bridgehead cladding with the semicircular part of the embedded part, placing spring bolts in the embedded holes, and connecting the bridgehead cladding and the abutment.

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