Portal frame construction method of fabricated steel-concrete composite structure

Abstract

The application relates to a portal frame construction method of a fabricated steel-concrete composite structure, which comprises the following steps: transporting a left-side prefabricated beam into a portal frame through a prefabricated beam transportation device, adjusting the left-side prefabricated beam to a left-right direction arrangement posture, transporting a right-side prefabricated beam into the portal frame, adjusting the right-side prefabricated beam to a left-right direction arrangement posture, adjusting the left-side prefabricated beam and the right-side prefabricated beam to a left-right direction collinear posture, integrally jacking up the left-side prefabricated beam and the right-side prefabricated beam through a left-side jacking mechanism, a middle jacking mechanism and a right-side jacking mechanism, integrally moving to a position corresponding to a left-side stand and a right-side stand, and connecting the left-side prefabricated beam with the left-side stand and the right-side prefabricated beam with the right-side stand. The application solves the technical problems that a plurality of cranes are needed to hoist the prefabricated beam in the prior art, the hoisting stability is poor, and the operation level of crane operators is required to be high.

Description

Technical Field

[0001] This invention relates to the field of building construction of large-span industrial plants, and more particularly to a method for constructing a portal frame of a prefabricated steel-concrete composite structure. Background Technology

[0002] Reinforced concrete portal frame structures are a common structural form for industrial plants and warehouse buildings. Compared with lightweight portal frame steel structures, they have advantages such as better fire resistance, airtightness, and durability, making them suitable for single-story, large-span buildings with high requirements for overall airtightness and watertightness. Currently, reinforced concrete portal frames have disadvantages such as larger beam and column dimensions and greater construction difficulty.

[0003] To meet functional requirements, hingeless portal frames typically have large single-span lengths, resulting in significant bending moments at beam-column connections and column-foundation connections. The beam and column components are also large, necessitating full-span scaffolding for roof beam and slab construction. This method is characterized by high construction difficulty, poor safety, high scaffolding material consumption, low formwork turnover efficiency, long construction period, and high cost. Furthermore, it significantly increases the difficulty of construction, particularly during open-air and high-altitude concrete pouring operations for pitched roofs.

[0004] Prefabricated steel-concrete composite portal frames exhibit clearly defined force distribution and a well-defined mechanical transmission path. Replacing reinforced concrete structures with technologically mature steel-concrete composite structures reduces component size and self-weight, facilitating factory fabrication and on-site installation. Prefabricated portal frames enable industrialized production in factories and direct on-site installation, ensuring high quality assurance, convenience, and speed, significantly shortening the construction period and improving construction quality and safety. Prefabricated steel-concrete composite portal frames primarily consist of precast beams and columns. However, due to the small number of components and the heavy weight of each individual component, conventional construction methods involve multiple cranes working in tandem. These cranes lift the precast beams to a height corresponding to the top of the precast columns, and then manually connect the beams and columns. The installation process heavily relies on the skill level of the crane operators, resulting in low efficiency and a low quality assurance rate, hindering large-scale mechanized and intelligent construction. Therefore, improving the automation and mechanization of prefabricated steel-concrete composite portal frame construction is of great significance. Summary of the Invention

[0005] The purpose of this invention is to provide a construction method for a portal frame of prefabricated steel-concrete composite structure, in order to solve the technical problems in the prior art that require multiple cranes to lift precast beams, resulting in poor lifting stability and high requirements for the operating skills of crane operators.

[0006] To solve the above-mentioned technical problems, the technical solution of the construction method of a portal frame for prefabricated steel-concrete composite structure in this invention is as follows:

[0007] A construction method for a prefabricated steel-concrete composite portal frame structure, the portal frame comprising columns and precast beams, wherein the columns include at least two pairs of columns spaced apart in the front-to-back direction, each pair of columns including two columns spaced apart in the left-to-right direction, the number of precast beams being the same as the number of column pairs, each precast beam including a left precast beam and a right precast beam arranged left and right, the adjacent ends of the left precast beams being precast beam connection ends, and the opposite ends of the left and right precast beams being column connection ends. The method includes the following steps: first, installing the columns at the construction site; second, installing individual precast beams, firstly transporting the left precast beams in the front-to-back direction to the corresponding columns using a precast beam transport device; the precast beam transport... The device includes a central lifting mechanism with wheels at the bottom. The precast beam transport device also includes a first and a second movable frame, whose upper ends are respectively supported at both ends of the left precast beam. The height of the first and second movable frames is lower than the height of the top of the columns. The central lifting mechanism is located in the middle of the two columns corresponding to a pair of columns. The upper end of the central lifting mechanism is provided with a central rotating shaft whose rotation axis extends vertically. The right end of the left precast beam is provided with a left precast beam connection structure that is detachably connected to the central rotating shaft. By adjusting the installation angle of the left precast beam through the first and second movable frames, the left precast beam rotates around the central rotating shaft axis, and the column connection end of the left precast beam rotates to the corresponding column. The left precast beam is arranged along the left-right direction, either on the front or rear side. The third step involves dismantling the connection between the left precast beam and the central pivot. Using the intermediate lifting mechanism, the third moving frame, and the fourth moving frame, the right precast beam is transported along the front-back direction to the corresponding column. The upper ends of the third and fourth moving frames are supported by the two ends of the right precast beam. The height of the third and fourth moving frames is lower than the height of the top of the column. The left end of the right precast beam has a connection structure that can be detachably connected to the central pivot. The installation angle of the right precast beam is adjusted using the third and fourth moving supports, allowing the right precast beam to rotate around the central pivot axis. The column connection end of the right precast beam rotates to the corresponding column. The first step is to move the precast beams on the front or back side, with the right precast beams arranged in the left-right direction. The second step is to move the precast beams on the right or left side back and forth so that the precast beams on the left and right sides are arranged in the same line in the left-right direction, and connect the precast beam connection ends of the precast beams on the left and right sides together. The third step is to raise the precast beams on the left and right sides simultaneously through the combined action of the left lifting mechanism, the right lifting mechanism and the middle lifting mechanism. The column connection ends of the precast beams on the left and right sides are not lower than the top height of the corresponding columns. The upper end of the left lifting mechanism is supported and cooperated with the lower end of the left precast beam, and the upper end of the right lifting mechanism is supported and cooperated with the lower end of the right precast beam. The bottom of the left and right lifting mechanisms are equipped with wheels.Step 6: Move the left and right precast beams forward and backward using the left, right, and middle lifting mechanisms, ensuring they are collinear with their corresponding pairs of columns in the left-right direction. Connect the column connection end of the left precast beam to the top of the left column, and connect the column connection end of the right precast beam to the top of the right column. Remove the left, right, and middle lifting mechanisms to complete the connection of a single precast beam to its corresponding pair of columns. Step 7: Repeat steps 2 through 6 to complete the connection of the remaining precast beams to their corresponding columns.

[0008] Furthermore, the column is a prefabricated column.

[0009] Furthermore, the precast beams on the left and right sides form an "eight"-shaped structure, and the upper ends of the first, second, third, and fourth mobile frames are supporting inclined surfaces adapted to the slope of the corresponding precast beams.

[0010] Furthermore, the heights of the first, second, third, and fourth movable frames cannot be adjusted.

[0011] Furthermore, the ground inside the portal frame is equipped with guide rails that extend in the front-to-back direction. The traveling wheels at the bottom of the intermediate lifting mechanism cooperate with the guide rails to guide the movement, and the guide rails are located in the middle of a pair of corresponding columns.

[0012] Furthermore, the upper end of the central rotating shaft is provided with a first connecting ear and a second connecting ear arranged symmetrically. The upper ends of the first connecting ear and the second connecting ear are provided with bolt connection structures for detachable connection with the left precast beam connection structure and the right precast beam connection structure, respectively.

[0013] The beneficial effects of this invention are as follows: When installing a single precast beam, the left and right precast beams are transported in stages. After adjusting the angle of the left precast beam using the first and second moving frames, the angle of the right precast beam is adjusted using the third and fourth moving frames. Finally, the left and right precast beams are adjusted into a straight structure arranged in the left-right direction, and the connection between the left and right precast beams is completed at a lower position. Finally, with the help of the lifting and movement of the left, right, and middle lifting mechanisms, the left and right precast beams are adjusted to be aligned with two of the corresponding columns in the left-right direction, completing the connection between the left precast beam and the column on the left, and the right precast beam and the column on the right, thus completing the installation of a single precast beam. This eliminates the need for multiple cranes with poor lifting stability to work together, reducing the difficulty of installing precast beams. Attached Figure Description

[0014] The above and other objects, features, and advantages of this disclosure will become readily apparent from the following detailed description of exemplary embodiments with reference to the accompanying drawings. In the drawings, several embodiments of this disclosure are illustrated by way of example and not limitation, and like or corresponding reference numerals denote like or corresponding portions, wherein:

[0015] Figure 1 This is a schematic diagram of the structure of the column after installation in this invention;

[0016] Figure 2 This is a schematic diagram showing the state of the left precast beam adjusting the installation angle in this invention;

[0017] Figure 3 This is a schematic diagram showing the state of the precast beam on the left after the installation angle has been adjusted to the correct position in this invention.

[0018] Figure 4 This is a schematic diagram showing the state of the precast beam on the right side after the installation angle has been adjusted to the correct position in this invention.

[0019] Figure 5 yes Figure 4 Side view;

[0020] Figure 6 This is a schematic diagram showing the state of the precast beam after it has been moved to the top of the corresponding column.

[0021] Figure 7 yes Figure 6 Side view;

[0022] Figure 8 yes Figure 5 Enlarged view of point A in the image;

[0023] Explanation of reference numerals in the attached drawings: 1. Left column; 2. Right column; 3. Guide rail; 4. Column connection structure; 5. Lower connecting steel plate; 6. Left precast beam; 7. Column connection end; 8. First moving frame; 9. Second moving frame; 10. Left lifting mechanism; 11. Middle lifting mechanism; 12. Central pivot; 13. Connecting end steel plate; 14. Left precast beam after installation angle adjustment; 15. Left precast beam during installation angle adjustment; 16. Track 1; 17. Precast beam after installation; 18. Right precast beam; 19. Third moving bracket; 20. Fourth moving bracket; 21. Track 2; 22. Right lifting mechanism; 23. First connecting ear; 24. Second connecting ear; 25. Bolted connection structure; 26. Left precast beam before installation angle adjustment. Detailed Implementation

[0024] To facilitate understanding of the present invention, a more detailed description is provided below with reference to the accompanying drawings and specific embodiments. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0025] It should be noted that, unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention.

[0026] An example of the implementation of the construction method for a prefabricated steel-concrete composite portal frame structure in this invention. Figures 1-8 As shown:

[0027] A construction method for a prefabricated steel-concrete composite portal frame structure, wherein the width of the portal frame extends in the left-right direction and the length of the portal frame extends in the front-back direction. The portal frame includes columns and precast beams. The columns include at least two pairs of columns spaced apart in the front-back direction. Each pair of columns includes two columns spaced apart in the left-right direction. The column on the left in each pair of columns is called the left column 1, and the column on the right is called the right column 2.

[0028] The number of precast beams is the same as the number of columns. Each precast beam includes a left precast beam 6 and a right precast beam 18, arranged on the left and right sides respectively. The adjacent ends of the left precast beam 6 are precast beam connection ends, and the opposite ends of the left and right precast beams are column connection ends 7. The top of the column is provided with a column connection structure 4 for connecting to the column connection ends. In this embodiment, the columns are precast columns. Both the columns and precast beams are prefabricated in the factory. Both the columns and precast beams include a steel reinforcement cage and concrete cast integrally with the steel reinforcement cage. The precast beam connection ends include vertically arranged connection end steel plates 13. The connection end steel plates 13 are provided with bolt holes. During connection, the connection end steel plates of the left and right precast beams are placed against each other, and bolts are inserted into the bolt holes to connect the left and right precast beams. The left and right precast beams form an "eight" shape structure. The column connection end includes a horizontally positioned upper column connecting steel plate. The column connection structure 4 includes a lower connecting steel plate 5 that is abutted against the lower end of the corresponding upper column connecting steel plate. Bolt holes are provided on both the upper and lower connecting steel plates. During connection, the upper and lower connecting steel plates are abutted against each other, and bolts are inserted through the bolt holes to connect the left precast beam to the left column, and vice versa. In other embodiments of the invention, the column can also be a cast-in-place structure.

[0029] The method includes the following steps: First, install the columns at the construction site; second, install individual precast beams. Firstly, transport the left precast beam 6 to the corresponding column using a precast beam transport device. During this process, the length of the left precast beam 6 is set along the front-back direction. The precast beam transport device includes a central lifting mechanism 11 with wheels at the bottom. The wheels of the central lifting mechanism 11 have braking devices. The precast beam transport device also includes a first mobile frame 8 and a second mobile frame 9, whose upper ends respectively support and cooperate with the two ends of the left precast beam. The tops of the first mobile frame 8 and the second mobile frame 9 are connected to the left precast beam. The supporting slope at the bottom of the beam is adapted. The height of the first and second moving frames is lower than the height of the top of the column. The middle lifting mechanism is located in the middle of the two columns corresponding to a pair of columns. The upper end of the middle lifting mechanism is equipped with a central rotating shaft 12 whose rotation axis extends in the vertical direction. The right end of the left precast beam is equipped with a left precast beam connection structure that can be detachably connected to the central rotating shaft. The ground between the left and right columns is equipped with a guide rail 3 whose guide direction extends in the front-back direction. The traveling wheels at the bottom of the middle lifting mechanism cooperate with the guide rail for guided movement. The left and right columns are symmetrically arranged on the left and right sides of the guide rail.

[0030] The heights of the first and second movable supports cannot be adjusted. After the precast beam on the left side is transported into place in the front-to-back direction, if... Figure 2 As shown, the position of the fixed intermediate lifting mechanism 11 is adjusted by the first and second moving frames, causing the left precast beam to rotate around the central axis. The column connection end of the left precast beam rotates to the rear of the corresponding column, and the left precast beam is arranged in the left-right direction. In this embodiment, the rear end of the left precast beam swings around the central axis, as shown... Figure 2 As shown, Figure 2 Item 26 represents the left precast beam before the installation angle is adjusted; item 14 represents the left precast beam after the installation angle is adjusted; item 15 represents the left precast beam during the installation angle adjustment process; item 16 represents trajectory 1, i.e., the rear end movement trajectory of the left precast beam. This continues until the left precast beam moves to the rear of the corresponding left column 1, at which point the length of the left precast beam extends in the left-right direction.

[0031] The third step involves dismantling the connection between the left precast beam 6 and the central rotating shaft 12. Using the intermediate lifting mechanism, the third moving frame 19, and the fourth moving frame 20, the right precast beam 18 is transported along the front-to-back direction to the corresponding column. The upper ends of the third and fourth moving frames are supported by the two ends of the right precast beam. The height of the third and fourth moving frames is lower than the height of the top of the column, and their height cannot be adjusted. The top of the third and fourth moving frames has a supporting slope that matches the bottom slope of the right precast beam. The left end of the right precast beam has a right precast beam connection structure that can be detachably connected to the central rotating shaft. The installation angle of the right precast beam is adjusted using the third and fourth moving frames, allowing the right precast beam to rotate around the central rotating shaft axis. Figure 4 As shown, the column connection end of the precast beam on the right is rotated to the rear side of the corresponding column, and the precast beam on the right is arranged in the left-right direction. Figure 4 Item 21 represents trajectory 2, which is the movement trajectory of the rear end of the precast beam on the right.

[0032] Fourth step: Move the precast beam on the right or left side back and forth so that the precast beams on the left and right sides are aligned in the left-right direction. Connect the precast beam ends of the left precast beam 6 and the right precast beam 18 together with bolts. Connect the right end of the left precast beam to the upper end of the central rotating shaft.

[0033] Step 5: The left and right precast beams are simultaneously raised by the combined action of the left lifting mechanism 10, the right lifting mechanism 22, and the middle lifting mechanism 11. The bottom of the left and right lifting mechanisms 10 and 22 are equipped with wheels with brakes. The column connection ends of the left and right precast beams are not lower than the top height of the corresponding columns. The upper end of the left lifting mechanism supports the lower end of the left precast beam, and the upper end of the right lifting mechanism supports the lower end of the right precast beam. Both the left and right lifting mechanisms are equipped with wheels at their bottoms. Step 6: The left and right precast beams are moved back and forth by the left, right, and middle lifting mechanisms, so that the left and right precast beams and their corresponding pairs of columns are collinear in the left-right direction. Figure 6 As shown, connect the column connection end of the left precast beam to the top of the left column, and connect the column connection end of the right precast beam to the top of the right column. Remove the left lifting mechanism, the right lifting mechanism and the middle lifting mechanism to complete the connection of a single precast beam with its corresponding pair of columns. Step 7: Repeat steps 2 to 6 to complete the connection of the remaining precast beams with their corresponding columns.

[0034] Then remove guide rail 3 from the ground.

[0035] In this embodiment, the upper end of the central rotating shaft is provided with symmetrically arranged first connecting ears 23 and second connecting ears 24. The upper ends of the first connecting ears 23 and second connecting ears 24 are respectively provided with bolt connection structures 25 for detachable connection with the left and right precast beam connection structures. Both the left and right precast beam connection structures include precast beam connecting plates. The bolt connection structure 25 includes connecting ear connecting plates connected to the corresponding connecting ears. Bolt holes are provided on the precast beam connecting plates and the connecting ear connecting plates. The bolt connection structure also includes connecting bolts inserted between the precast beam connecting plates and the connecting ear connecting plates. When it is necessary to separate the precast beam from the intermediate lifting mechanism, the connecting bolts can be removed.

[0036] In this embodiment, the left and right lifting mechanisms are both scissor-type lifting mechanisms, while the middle lifting mechanism is a lifting mechanism with multiple standard sections. Its lifting principle is the same as the height adjustment method of the tower crane column (tower body), including multiple standard sections that can be added or removed vertically. In other embodiments of the present invention, the middle lifting mechanism may also be a scissor-type lifting mechanism or a multi-stage hydraulic cylinder lifting mechanism with multiple telescopic sections; the left and right lifting mechanisms may also be multi-stage hydraulic cylinder lifting mechanisms with multiple telescopic sections.

[0037] In the foregoing description of this specification, unless otherwise expressly specified and limited, the terms "fixed," "installed," "connected," or "linked" should be interpreted broadly. For example, the term "linked" can refer to a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; or it can refer to the internal communication of two components or the interaction between two components. Therefore, unless otherwise expressly limited in this specification, those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0038] Based on the above description in this specification, those skilled in the art will also understand that terms used, such as "upper," "lower," "front," "rear," "left," "right," "length," "width," "thickness," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," "circumferential," "center," "longitudinal," "transverse," "clockwise," or "counterclockwise," are terms indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings of this specification. They are only for the purpose of facilitating the explanation of the present invention and simplifying the description, and do not imply that the devices or elements involved must have the specific orientation, or be constructed and operated in a specific orientation. Therefore, the above-mentioned orientation or positional relationship terms should not be understood or interpreted as limitations on the present invention.

[0039] Furthermore, the terms "first" or "second," etc., used in this specification to refer to numbers or ordinal numbers are for descriptive purposes only and should not be construed as indicating, explicitly or implicitly, relative importance or specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this specification, "a plurality of" means at least two, such as two, three, or more, unless otherwise explicitly specified.

[0040] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A construction method for a prefabricated steel-concrete composite portal frame, the portal frame comprising columns and precast beams, the columns comprising at least two pairs of columns spaced apart in the front-to-back direction, each pair of columns comprising two columns spaced apart in the left-to-right direction, the number of precast beams being the same as the number of column pairs, each precast beam comprising a left precast beam and a right precast beam arranged left and right, the adjacent ends of the left precast beams being precast beam connection ends, and the opposite ends of the left and right precast beams being column connection ends, characterized in that: The method includes the following steps: First, install the columns at the construction site; second, install individual precast beams. Firstly, transport the left precast beam along the front-to-back direction to the corresponding columns using a precast beam transport device. The precast beam transport device includes a central lifting mechanism with wheels at the bottom, and also includes a first and second movable frame whose upper ends respectively support the two ends of the left precast beam. The height of the first and second movable frames is lower than the height of the top of the columns. The central lifting mechanism is located in the middle of the two columns corresponding to a pair of columns. The upper end of the central lifting mechanism is equipped with a central rotating shaft whose rotation axis extends vertically. The right end of the left precast beam is equipped with a left precast beam that is detachably connected to the central rotating shaft. The connection structure adjusts the installation angle of the left precast beam via the first and second movable frames, allowing the left precast beam to rotate around the central axis. The column connection end of the left precast beam rotates to the front or rear of the corresponding column, and the left precast beam is arranged in the left-right direction. The third step involves disassembling the connection between the left precast beam and the central axis. Using the intermediate lifting mechanism, the third movable frame, and the fourth movable frame, the right precast beam is transported in the front-back direction to the corresponding columns. The upper ends of the third and fourth movable frames are supported at both ends of the right precast beam. The height of the third and fourth movable frames is lower than the top of the columns. The left end of the right precast beam is equipped with a right precast beam connection structure that can be detachably connected to the central axis. The first step involves adjusting the installation angle of the right precast beam using the fourth moving frame, causing it to rotate around the central axis. The column connection end of the right precast beam rotates to the front or rear of the corresponding column, and the right precast beam is arranged along the left-right direction. The second step involves moving the entire right or left precast beam back and forth, aligning it with the left and right precast beams along the same left-right direction, and connecting the precast beam connection ends together. The third step involves simultaneously raising the left and right precast beams using the combined action of the left, right, and middle lifting mechanisms. The column connection ends of the left and right precast beams are not lower than the top height of the corresponding columns, and the upper end of the left lifting mechanism is connected to the left precast beam. The lower end is supported and engaged, and the upper end of the right lifting mechanism is supported and engaged with the lower end of the right precast beam. The bottom of both the left and right lifting mechanisms are equipped with traveling wheels. In the sixth step, the left and right precast beams are moved back and forth by the left, right, and middle lifting mechanisms so that the left and right precast beams and their corresponding pairs of columns are collinear in the left and right directions. The column connecting end of the left precast beam is connected to the top of the left column, and the column connecting end of the right precast beam is connected to the top of the right column. The left, right, and middle lifting mechanisms are then removed to complete the connection of a single precast beam with its corresponding pair of columns. In the seventh step, steps two through six are repeated to complete the connection of the remaining precast beams with their corresponding columns.

2. The construction method for a portal frame of a prefabricated steel-concrete composite structure according to claim 1, characterized in that: The columns are prefabricated.

3. The construction method for a portal frame of a prefabricated steel-concrete composite structure according to claim 1, characterized in that: The precast beams on the left and right sides form an "eight" shape. The upper ends of the first, second, third, and fourth mobile frames are support slopes that are adapted to the slope of the corresponding precast beams.

4. The construction method for a portal frame of a prefabricated steel-concrete composite structure according to claim 3, characterized in that: The heights of the first, second, third, and fourth mobile frames cannot be adjusted.

5. The construction method for a portal frame of a prefabricated steel-concrete composite structure according to claim 1, characterized in that: Inside the portal frame, there are guide rails on the ground that extend in the front-to-back direction. The traveling wheels at the bottom of the central lifting mechanism move in coordination with the guide rails, which are located in the middle of a pair of corresponding columns.

6. The construction method for a portal frame of a prefabricated steel-concrete composite structure according to any one of claims 1 to 5, characterized in that: The upper end of the central rotating shaft is provided with a first connecting ear and a second connecting ear arranged symmetrically. The upper ends of the first connecting ear and the second connecting ear are provided with bolt connection structures for detachable connection with the precast beam connection structure on the left and the precast beam connection structure on the right, respectively.

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