Bridge structure extension structure and construction method

By using old bridge decks, extended bridge decks, connecting components and other components in the bridge structure, the extension and reinforcement of the bridge structure is achieved, solving the problem that bridge structures are difficult to achieve when widening or extending in the existing technology, and improving the functional expansion capability and service life of the bridge.

CN119553585APending Publication Date: 2025-03-04CHINA MCC17 GRP CO LTD
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Patent Information

Application Number
CN202510021600.4
Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Filing Date
2025-01-07
Publication Date
2025-03-04

AI Technical Summary

Technical Problem

The existing bridge structure is difficult to achieve without interrupting traffic when widening, extending or enhancing load capacity, and the existing reinforcement methods are expensive and affecting road access.

Method used

The structural design includes old bridge deck panels, extended bridge deck panels, connecting components, expansion joints, main bearing beams, secondary support beams and bridge pier caps is adopted. The bridge structure is extended and reinforced through prefabricated design and standardized connection methods.

Benefits of technology

The bridge structure is extended and reinforced without interrupting traffic, which improves the functional expansion ability and service life of the bridge and reduces the construction difficulty and time.

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Abstract

The invention discloses a bridge structure extension structure which comprises an old bridge deck slab and an extension bridge deck slab installed at the outer end of the old bridge deck slab, a connecting assembly is installed between the old bridge deck slab and the extension bridge deck slab, an expansion joint is reserved between the old bridge deck slab and the extension bridge deck slab, and a plurality of bridge pier caps are arranged at the bottoms of the old bridge deck slab and the extension bridge deck slab in the length direction. A plurality of main bearing beams are transversely and uniformly arranged between the bottoms of the old bridge deck slab and the extended bridge deck slab and the bridge pier caps at intervals, a plurality of pairs of auxiliary supporting beams are transversely and uniformly arranged between the main bearing beams and the bottoms of the old bridge deck slab and the extended bridge deck slab at intervals, and each pair of auxiliary supporting beams are connected and fixed through waist steel plates matched with bolts. According to the bridge structure extension structure and the construction method, construction convenience is fully considered, modular assembly is carried out through standard connection modes such as bolts and insertion holes, the site construction difficulty is reduced, the construction efficiency is greatly improved through the prefabricated design of the connecting assemblies, bridge extension operation can be completed more quickly, and the construction time is saved.
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Description

Technical Field

[0001] The invention belongs to the technical field of bridge construction, and in particular relates to a bridge structure extension structure and a construction method. Background Art

[0002] With the development of transportation, bridge engineering has occupied an important position in modern infrastructure construction. Bridges are usually composed of multiple structural components, including bridge decks, piers, supporting structures, etc. The stability and durability of bridge structures are crucial to the service life of bridges. However, in some special application scenarios, such as when bridges need to be widened, extended, or their load-bearing capacity is enhanced, the existing bridge structure design is difficult to meet these requirements, especially when extending the bridge structure without interrupting traffic.

[0003] In the existing technology, common bridge widening and extension methods usually rely on the construction of a new bridge, or require complete closure of traffic for complex reinforcement work; for bridges in use, implementing these methods is not only expensive, but also affects road traffic. In view of this, there is an urgent need for a structure and construction method that can extend the bridge structure without interrupting traffic, so as to improve the functional expansion capacity of the bridge and meet the needs of future transportation. Summary of the invention

[0004] In view of the problems existing in the above-mentioned background technology, the present invention provides a bridge structure extension structure and a construction method.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] The present invention provides a bridge structure extension structure, which includes an old bridge deck and an extended bridge deck installed on the outer end of the old bridge deck, a connecting component is installed between the old bridge deck and the extended bridge deck and an expansion joint is left, a plurality of pier caps are arranged at the bottom along the length direction of both, a plurality of main bearing beams are arranged at uniform intervals laterally between the bottom of both and each of the pier caps, a plurality of pairs of secondary supporting beams are arranged at uniform intervals laterally between each of the main bearing beams and the bottom of the old bridge deck and the extended bridge deck, and each pair of the secondary supporting beams is connected and fixed by waist steel plates and bolts.

[0007] Furthermore, the connecting component includes an S-shaped steel plate 1, a first steel frame is installed on the side of the S-shaped steel plate 1 close to the old bridge deck, and the first steel frame is prefabricated and embedded in the old bridge deck, and an angled steel frame 1 is installed on the side of the S-shaped steel plate 1 close to the extended bridge deck, and the angled steel frame 1 is prefabricated and embedded in the extended bridge deck; an S-shaped steel plate 2 is installed at a position rotated 180° clockwise around the transverse center axis of the S-shaped steel plate 1, a second steel frame is installed on the side of the S-shaped steel plate 2 close to the extended bridge deck, and the second steel frame is prefabricated and embedded in the extended bridge deck, and an angled steel frame 2 is installed on the side of the S-shaped steel plate 2 close to the old bridge deck, and the angled steel frame 2 is prefabricated and embedded in the old bridge deck.

[0008] Furthermore, a through hole is opened in the middle of the surface of the S-shaped steel plate 1 and is evenly spaced along the transverse direction, and the connection between the S-shaped steel plate 1 and the first steel frame and the angled steel frame 1 is fixedly connected with a first arc-shaped steel plate; a first screw is threadedly installed on the first arc-shaped steel plate at an evenly spaced interval along the transverse direction, and the S-shaped steel plate 1 is threadedly installed with the first steel frame and the angled steel frame 1 respectively through the cooperation of the first screw and the first arc-shaped steel plate;

[0009] Furthermore, the first arc-shaped steel plate and the S-shaped steel plate are designed as an integrated whole.

[0010] Furthermore, the portion where the S-shaped steel plate 2 is connected to the second steel frame and the angled steel frame 2 is fixedly connected to a second arc-shaped steel plate, and a second screw is threadedly installed on the second arc-shaped steel plate at equal intervals along the transverse direction; the S-shaped steel plate 2 is threadedly installed with the second steel frame and the angled steel frame 2 respectively through the cooperation of the second arc-shaped steel plate and the second screw; the S-shaped steel plate 2 is provided with a plurality of protrusions matching the through-holes at intervals and is cross-assembled with the S-shaped steel plate 1 through the through-holes, and the S-shaped steel plate 2 and the S-shaped steel plate 1 together form a cylindrical tensile deformation structure.

[0011] Furthermore, each waist steel plate is symmetrically installed on the two ends of each pair of auxiliary support beams by bolts, and screw holes are opened at the upper and lower parts of both ends of each pair of auxiliary support beams along the longitudinal direction. Large screws are installed in the inner threads of the screw holes, and the upper and lower parts of the auxiliary support beams are respectively connected and fixed to the old bridge deck and the pier cap by the cooperation of the large screws and the screw holes.

[0012] Furthermore, the symmetrical end faces of the pier caps along the longitudinal direction are provided with sockets, and the main bearing beams are respectively plugged into the pier caps through the sockets.

[0013] The present invention provides a construction method for extending a bridge structure, which comprises the following steps:

[0014] S1. A pier cap is set at the part to be extended in the longitudinal direction of the existing old bridge deck, and the main bearing beam and the pier cap are inserted on the part to be extended in the longitudinal direction of the old bridge deck to provide support for the part to be extended;

[0015] S2. Then, the auxiliary support beams of the old bridge deck to be extended are extended and assembled in the longitudinal direction through the waist steel plate, and a corresponding number of auxiliary support beams are installed in the longitudinal direction. The head and tail ends of the auxiliary support beams are bolted and connected and extended through the waist steel plate, and the extended auxiliary support beams are bolted to the top of the pier cap through the screw holes and large screws. After each auxiliary support beam of a longitudinal length unit is installed, a pier cap is added;

[0016] S3. Then, a prefabricated extended bridge deck is installed between the two pier caps. Prior to this, the connection components are installed side by side in an even number of pairs at the end surfaces where the old bridge deck and the extended bridge deck are assembled. Specifically, the second steel frame and the angled steel frame are prefabricated side by side in the extended bridge deck along the transverse direction of the extended bridge deck, and the angled steel frame 1 and the second steel frame are exposed at one end close to the old bridge deck, so as to facilitate the installation with the S-shaped steel plate 1 and the S-shaped steel plate 2 by bolts; the first steel frame and the angled steel frame 2 are prefabricated side by side in the old bridge deck along the transverse direction of the old bridge deck, and the first steel frame and the angled steel frame 2 are exposed at one end close to the extended bridge deck, so as to facilitate the installation with the S-shaped steel plate 1 and the S-shaped steel plate 2 by bolts;

[0017] S4. Align the first steel frame on the old bridge deck with the S-shaped steel plate 1 and install them with bolts, and associate the angled steel frame 2 on the old bridge deck with the S-shaped steel plate 2 and install them with bolts; then associate the second steel frame on the extended bridge deck with the S-shaped steel plate 2 and install them with bolts, associate the angled steel frame 1 on the extended bridge deck with the S-shaped steel plate 1 and install them with bolts, then squeeze the extended bridge deck toward the old bridge deck along the longitudinal direction, at this time, bolt the top of the secondary support beam in contact with the bottom of the old bridge deck and the extended bridge deck, so that a pair of waist steel plates at the adjacent ends of the two groups of secondary support beams can correspond one by one with the connecting components in the vertical direction, and complete the extension construction of the old bridge deck.

[0018] Compared with the prior art, the bridge structure extension structure and construction method described in the present invention have the following beneficial effects:

[0019] (1) The bridge structure extension structure and construction method described in the present invention ensure a firm connection between the old bridge and the extended bridge part through the dual fixing design of the steel frame and the S-shaped steel plate in the connecting assembly, effectively improve the stability of the overall bridge structure, and reduce the risk of damage caused by stress concentration.

[0020] (2) The bridge structure extension structure and construction method described in the present invention reserve sufficient deformation space by designing a deformable cylindrical tensile structure and expansion joint between the old bridge deck and the extended bridge deck; this not only effectively prevents structural damage caused by rigid connections, but also ensures the stability and durability of the bridge deck under different environmental conditions, especially has better adaptability under temperature changes and load fluctuations.

[0021] (3) The bridge structure extension structure and construction method described in the present invention, by combining expansion joints and deformable structure designs, can effectively reduce structural stress damage to the bridge caused by rigid connections, thereby extending the service life of the bridge; its overall design is safer and more reliable, and effectively prevents damage to the bridge deck caused by thermal expansion and contraction or load fluctuations.

[0022] (4) The bridge extension structure and construction method described in the present invention fully consider the convenience of construction, and modularize the assembly through standardized connection methods such as bolts and sockets, thereby reducing the difficulty of on-site construction. The prefabricated design of the connection components greatly improves the construction efficiency, allowing the bridge extension operation to be completed faster, saving construction time. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the external structure of a bridge structure extension structure and a construction method of the present invention;

[0024] Figure 2 It is a schematic diagram of the installation structure of the connection assembly of the present invention between the old bridge deck and the extended bridge deck;

[0025] Figure 3 This is a schematic diagram of the partially disassembled structure of the extended bridge deck through the secondary support beam and the pier cap of the present invention;

[0026] Figure 4 It is a structural schematic diagram of the bridge pier cap of the present invention;

[0027] Figure 5 It is a schematic diagram of the disassembled structure of the connection assembly of the present invention and the old bridge deck and the extended bridge deck;

[0028] Figure 6 It is a schematic diagram of the overall structure of the connection assembly of the present invention;

[0029] Figure 7 It is a schematic diagram of the assembly structure of the first steel frame, the angled steel frame 1 and the shaped steel plate 1 of the present invention;

[0030] Figure 8 This is a schematic structural diagram of an S-shaped steel plate of the present invention;

[0031] Fig. 9 It is a schematic diagram of the assembly structure of the second S-shaped steel plate, the second steel frame and the second angled steel frame of the present invention;

[0032] Fig.10 It is a structural schematic diagram of the S-shaped steel plate 2 of the present invention;

[0033] Fig.11 It is a schematic diagram of the partial assembly structure of the auxiliary support beam and the waist steel plate of the present invention.

[0034] In the figure: 1. old bridge deck; 2. pier cap; 3. main bearing beam; 4. extended bridge deck; 5. connection assembly; 6. secondary supporting beam; 7. waist steel plate; 21. socket; 51. first steel frame; 52. angle steel frame one; 53. S-shaped steel plate one; 54. S-shaped steel plate two; 55. second steel frame; 56. angle steel frame two; 531. through-hole; 532. first screw; 533. first arc-shaped steel plate; 541. second arc-shaped steel plate; 542. second screw; 61. screw hole. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention. Unless otherwise defined, the technical terms or scientific terms used herein should be the usual meanings understood by people with general skills in the field to which the present disclosure belongs. "Up", "down", "left", "right", "front", "back" and the like used in the patent application specification and claims of the present disclosure are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship also changes accordingly. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. The parts not described in detail in the present invention are all known technologies of technicians in the field of this technology.

[0036] Embodiment 1:

[0037] Please refer to Figure 1-11A bridge structure extension structure includes an old bridge deck 1 and an extended bridge deck 4 installed at the outer end of the old bridge deck 1, a connecting component 5 is installed between the old bridge deck 1 and the extended bridge deck 4 and an expansion joint is left, a plurality of pier caps 2 are arranged at the bottom along the length direction of the two, a plurality of main bearing beams 3 are arranged at uniform intervals laterally between the bottom of the two and each pier cap 2, a plurality of pairs of secondary supporting beams 6 are arranged at uniform intervals laterally between each main bearing beam 3 and the bottom of the old bridge deck 1 and the extended bridge deck 4, and each pair of secondary supporting beams 6 is connected and fixed by a waist steel plate 7 with bolts. In this embodiment, the main load-bearing beam 3 and the auxiliary support beam 6 extend longitudinally along the old bridge deck 1 respectively, and are used to bear the weight of the extended part. The auxiliary support beam 6 is made of high-strength alloy steel material, has strong bending and compression resistance, and is suitable for the extension of large-span bridges. The combined use of the main load-bearing beam and the auxiliary support beam greatly improves the bearing capacity of the bridge. In particular, the auxiliary support beam made of high-strength alloy steel can effectively support the weight of the extended bridge deck, ensuring the stability and safety of the bridge in the large-span structure; by setting an expansion joint between the old bridge deck and the extended bridge deck, combined with the deformable design of the connecting component, it can effectively adapt to the expansion and contraction movement of the bridge deck caused by temperature changes or load changes, and maintain the flatness and stability of the bridge deck; the pier cap 2 is used to support the connection between the old bridge deck 1 and the extended bridge deck 4 and the extended bridge deck 4. The extended bridge deck 4 is made of weather-resistant concrete material, which can adapt to the use requirements of long-term exposure to the natural environment, thereby increasing the durability of the bridge.

[0038] In this embodiment, the connecting component 5 includes an S-shaped steel plate 53, and a first steel frame 51 is installed on the side of the S-shaped steel plate 53 close to the old bridge deck 1, and the first steel frame 51 is prefabricated and embedded in the old bridge deck 1, and an angle steel frame 52 is installed on the side of the S-shaped steel plate 53 close to the extended bridge deck 4, and the angle steel frame 52 is prefabricated and embedded in the extended bridge deck 4; an S-shaped steel plate 54 is installed at a position rotated 180° clockwise around the transverse center axis of the S-shaped steel plate 53, and a second steel frame 55 is installed on the side of the S-shaped steel plate 54 close to the extended bridge deck 4, and the second steel frame 55 is prefabricated and embedded in the extended bridge deck 4, and an angle steel frame 56 is installed on the side of the S-shaped steel plate 54 close to the old bridge deck 1, and the angle steel frame 56 is prefabricated and embedded in the old bridge deck 1.

[0039] In this embodiment, a through hole 531 is provided in the middle of the surface of the S-shaped steel plate 53 at equal intervals along the transverse direction, and the connection between the S-shaped steel plate 53 and the first steel frame 51 and the angled steel frame 52 is fixedly connected with a first arc-shaped steel plate 533; the first arc-shaped steel plate 533 is threadedly installed with a first screw rod 532 at equal intervals along the transverse direction, and the S-shaped steel plate 53 is threadedly installed with the first steel frame 51 and the angled steel frame 52 respectively through the cooperation of the first screw rod 532 and the first arc-shaped steel plate 533;

[0040] In this embodiment, the first arc-shaped steel plate 533 and the S-shaped steel plate 1 53 are designed as an integral whole.

[0041] In this embodiment, the portion where the S-shaped steel plate 54 is connected to the second steel frame 55 and the angle steel frame 56 is fixedly connected with the second arc-shaped steel plate 541, and the second arc-shaped steel plate 541 is threadedly installed with second screws 542 at equal intervals along the transverse direction; the S-shaped steel plate 54 is threadedly installed with the second steel frame 55 and the angle steel frame 56 respectively through the cooperation of the second arc-shaped steel plate 541 and the second screw 542; the S-shaped steel plate 54 is provided with a plurality of protrusions matching the through-hole 531 at intervals and is cross-assembled with the S-shaped steel plate 1 53 through the through-hole 531, and the S-shaped steel plate 54 and the S-shaped steel plate 1 53 together form a cylindrical tensile deformation structure, which is convenient for cooperating with the reserved expansion joint, so that the old bridge deck 1 and the extended bridge deck 4 can have a certain deformable space in the longitudinal direction, avoiding the rigid connection between the extended portion and the old bridge deck 1, which may cause the subsequent damage of the extended bridge deck 4.

[0042] In this embodiment, each waist steel plate 7 is symmetrically installed at the two ends of each pair of auxiliary support beams 6 by bolts. Screw holes 61 are provided at the upper and lower ends of each pair of auxiliary support beams 6 along the longitudinal direction. Large screws are installed in the inner threads of the screw holes 61. The upper and lower parts of the auxiliary support beams 6 are respectively connected and fixed to the old bridge deck 1 and the pier cap 2 by the large screws and screw holes 61. The standardized installation method of the auxiliary support beams by screw holes and screws allows the bridge extension construction to be carried out in stages and modularly, which is convenient for installation and adjustment during the construction process. The setting of the pier cap also allows the flexible addition of support structures during the extension construction process.

[0043] In this embodiment, the symmetrical end faces of the pier cap 2 along the longitudinal direction are provided with sockets 21, and each main bearing beam 3 is respectively inserted into the pier cap 2 through the sockets 21. The pier cap 2 is installed between the main bearing beam 3 and the ground, and the height of the pier cap 2 can be specifically installed and adjusted according to the terrain and load conditions to provide a stable supporting force.

[0044] Embodiment 2:

[0045] The present invention provides a construction method for extending a bridge structure, which comprises the following steps:

[0046] S1. A pier cap 2 is provided at the part to be extended in the longitudinal direction of the existing old bridge deck 1, and the main bearing beam 3 on the part to be extended in the longitudinal direction of the old bridge deck 1 is inserted with the pier cap 2 to provide support for the part to be extended; the insertion design between the main bearing beam and the pier cap ensures the stability of the bridge structure and avoids damage caused by stress concentration at the structural connection;

[0047] S2, then the auxiliary support beams 6 of the part to be extended of the old bridge deck 1 are extended in the longitudinal direction through the waist steel plate 7, and a corresponding number of auxiliary support beams 6 are installed in the longitudinal direction, and the head and tail ends of the auxiliary support beams 6 are bolted and connected and extended by the waist steel plate 7, and the extended auxiliary support beams 6 are bolted to the top of the pier cap 2 through the screw holes 61 and the large screws, and after each auxiliary support beam 6 of a longitudinal length unit is installed, a pier cap 2 is added;

[0048] S3. Then, a prefabricated extended bridge deck 4 is installed between the two bridge pier caps 2. Prior to this, the connection components 5 are installed side by side in an even number of pairs at the end surfaces where the old bridge deck 1 and the extended bridge deck 4 are assembled. Specifically, the second steel frame 55 and the angled steel frame 1 52 are a pair, and are prefabricated and installed side by side in the extended bridge deck 4 along the transverse direction of the extended bridge deck 4, and the angled steel frame 1 52 and the second steel frame 55 are exposed at one end close to the old bridge deck 1, so as to facilitate the installation with the S-shaped steel plate 1 53 and the S-shaped steel plate 2 54 bolts; the first steel frame 51 and the angled steel frame 2 56 are a pair, and are prefabricated and installed side by side in the old bridge deck 1 along the transverse direction of the old bridge deck 1, and the first steel frame 51 and the angled steel frame 2 56 are exposed at one end close to the extended bridge deck 4, so as to facilitate the installation with the S-shaped steel plate 1 53 and the S-shaped steel plate 2 54 bolts; the connection components are installed with the S-shaped steel plate and the first and second steel frames by bolts, thereby enhancing the connection strength between the old bridge and the extended part;

[0049] S4, the first steel frame 51 on the old bridge deck 1 is bolted to the S-shaped steel plate 1 53, and the angled steel frame 2 56 on the old bridge deck 1 is bolted to the S-shaped steel plate 2 54; then the second steel frame 55 on the extended bridge deck 4 is bolted to the S-shaped steel plate 2 54, and the angled steel frame 1 52 on the extended bridge deck 4 is bolted to the S-shaped steel plate 1 53, and then the extended bridge deck 4 is pressed toward the old bridge deck 1 along the longitudinal direction, and at this time, the top of the secondary support beam 6 is bolted to the part in contact with the bottom of the old bridge deck 1 and the extended bridge deck 4, so that a pair of waist steel plates 7 at the adjacent ends of the two groups of secondary support beams 6 can correspond to the connection components 5 in the vertical direction, and the extension construction of the old bridge deck 1 is completed. The structure and method fully consider the convenience of construction, and modular assembly is performed through standardized connection methods such as bolts and sockets, which reduces the difficulty of on-site construction; the prefabricated design of the connection components greatly improves the construction efficiency, so that the bridge extension operation can be completed faster, saving construction time.

Claims

1. A bridge structure extension structure, characterized in that: The invention comprises an old bridge deck (1) and an extended bridge deck (4) installed at the outer end of the old bridge deck (1), a connecting assembly (5) is installed between the old bridge deck (1) and the extended bridge deck (4) and an expansion joint is left, a plurality of bridge pier caps (2) are arranged at the bottom of the two along the length direction, a plurality of main bearing beams (3) are arranged at uniform intervals in the transverse direction between the bottom of the two and each of the bridge pier caps (2), a plurality of pairs of secondary supporting beams (6) are arranged at uniform intervals in the transverse direction between each of the main bearing beams (3) and the bottom of the old bridge deck (1) and the extended bridge deck (4), and each pair of the secondary supporting beams (6) is connected and fixed by a waist steel plate (7) with bolts.

2. A bridge structure extension structure according to claim 1, characterized in that: The connection assembly (5) comprises an S-shaped steel plate (53), a first steel frame (51) is installed on a side of the S-shaped steel plate (53) close to the old bridge deck (1), and the first steel frame (51) is prefabricated and embedded in the old bridge deck (1); a folded angle steel frame (52) is installed on a side of the S-shaped steel plate (53) close to the extended bridge deck (4), and the folded angle steel frame (52) is prefabricated and embedded in the extended bridge deck (4); a plurality of steel frames (51) are connected to the S-shaped steel plate (53) to form a plurality of steel frames (51) connected to the S-shaped steel plate (53); and a plurality of steel frames (51) are connected to the S-shaped steel plate (53). An S-shaped steel plate 2 (54) is installed at a position rotated 180° clockwise from the transverse center axis of the bridge 53), and a second steel frame (55) is installed on the side of the S-shaped steel plate 2 (54) close to the extended bridge deck (4), and the second steel frame (55) is prefabricated and embedded in the extended bridge deck (4), and an angled steel frame 2 (56) is installed on the side of the S-shaped steel plate 2 (54) close to the old bridge deck (1), and the angled steel frame 2 (56) is prefabricated and embedded in the old bridge deck (1).

3. A bridge structure extension structure according to claim 2, characterized in that: A through hole (531) is provided in the middle of the surface of the S-shaped steel plate (53) and is evenly spaced along the transverse direction. The connection between the S-shaped steel plate (53) and the first steel frame (51) and the angled steel frame (52) is fixedly connected with a first arc-shaped steel plate (533); a first screw rod (532) is threadedly installed on the first arc-shaped steel plate (533) at an evenly spaced interval along the transverse direction. The S-shaped steel plate (53) is threadedly installed with the first steel frame (51) and the angled steel frame (52) respectively through the cooperation of the first screw rod (532) and the first arc-shaped steel plate (533).

4. The bridge structure extension structure according to claim 3, characterized in that: The first arc-shaped steel plate (533) and the S-shaped steel plate (53) are of an integrated design.

5. The bridge structure extension structure according to claim 3, characterized in that: The portion where the S-shaped steel plate 2 (54) is connected to the second steel frame (55) and the angled steel frame 2 (56) is fixedly connected with a second arc-shaped steel plate (541), and a second screw rod (542) is threadedly installed on the second arc-shaped steel plate (541) at equal intervals along the transverse direction; the S-shaped steel plate 2 (54) is threadedly installed with the second steel frame (55) and the angled steel frame 2 (56) respectively through the cooperation of the second arc-shaped steel plate (541) and the second screw rod (542); a plurality of protrusions matching the through-hole (531) are arranged on the S-shaped steel plate 2 (54) at intervals, and are cross-assembled with the S-shaped steel plate 1 (53) through the through-hole (531), and the S-shaped steel plate 2 (54) and the S-shaped steel plate 1 (53) together form a cylindrical tensile deformation structure.

6. A bridge structure extension structure according to any one of claims 1 to 5, characterized in that: Each waist steel plate (7) is symmetrically installed at the two ends of each pair of auxiliary support beams (6) by bolts. The upper and lower parts of both ends of each pair of auxiliary support beams (6) along the longitudinal direction are provided with screw holes (61). Large screws are installed in the internal threads of the screw holes (61). The upper and lower parts of the auxiliary support beams (6) are respectively connected and fixed to the old bridge deck (1) and the pier cap (2) by the cooperation of the large screws and the screw holes (61).

7. The bridge structure extension structure according to claim 6, characterized in that: The pier cap (2) is provided with a socket (21) on the symmetrical end surface along the longitudinal direction, and each of the main bearing beams (3) is respectively inserted into the pier cap (2) through the socket (21).

8. A construction method for extending a bridge structure, characterized in that: The following steps are involved: S1. A bridge pier cap (2) is provided at the portion to be extended in the longitudinal direction of the existing old bridge deck (1), and the main bearing beam (3) on the portion to be extended in the longitudinal direction of the old bridge deck (1) is inserted into the bridge pier cap (2) to provide support for the portion to be extended; S2, then, the auxiliary support beam (6) of the part to be extended of the old bridge deck (1) is extended in the longitudinal direction through the waist steel plate (7), and a corresponding number of auxiliary support beams (6) are installed in the longitudinal direction, and the front and rear ends of the auxiliary support beam (6) are bolted and connected and extended through the waist steel plate (7), and the extended auxiliary support beam (6) is bolted to the top of the pier cap (2) through the screw hole (61) and the large screw, and after each auxiliary support beam (6) of a longitudinal length unit is installed, a pier cap (2) is added; S3. Then, a prefabricated extended bridge deck (4) is installed between the two bridge pier caps (2). Prior to this, the connection components (5) are installed side by side in an even number of pairs at the end surfaces where the old bridge deck (1) and the extended bridge deck (4) are assembled. Specifically, the second steel frame (55) and the angled steel frame (52) are prefabricated side by side in the extended bridge deck (4) along the transverse direction of the extended bridge deck (4), and the angled steel frame (52) and the second steel frame (55) are close to the old bridge deck. One end of the panel (1) is exposed, so that it is convenient to install with the S-shaped steel plate 1 (53) and the S-shaped steel plate 2 (54) by bolts; the first steel frame (51) and the angled steel frame 2 (56) are prefabricated and installed side by side in the old bridge panel (1) along the transverse direction of the old bridge panel (1), and one end of the first steel frame (51) and the angled steel frame 2 (56) close to the extended bridge panel (4) is exposed, so that it is convenient to install with the S-shaped steel plate 1 (53) and the S-shaped steel plate 2 (54) by bolts; S4. The first steel frame (51) on the old bridge deck (1) is aligned with the S-shaped steel plate 1 (53) and bolted, and the angled steel frame 2 (56) on the old bridge deck (1) is aligned with the S-shaped steel plate 2 (54) and bolted; then the second steel frame (55) on the extended bridge deck (4) is aligned with the S-shaped steel plate 2 (54) and bolted, and the angled steel frame 1 (52) on the extended bridge deck (4) is aligned with the S-shaped steel plate 1 (53) and bolted, and then the extended bridge deck (4) is pressed toward the old bridge deck (1) along the longitudinal direction. At this time, the top of the auxiliary support beam (6) is bolted to the contact part of the old bridge deck (1) and the bottom of the extended bridge deck (4), so that a pair of waist steel plates (7) at the adjacent ends of the two groups of auxiliary support beams (6) can correspond one by one with the connecting assembly (5) in the vertical direction, and the extension construction of the old bridge deck (1) is completed.