Construction method of cofferdam dam

Abstract

The invention relates to the technical field of water conservancy projects, in particular to a cofferdam dam construction method which comprises the following steps that S1, after the offshore construction position is determined, a supporting column is lowered, and it is guaranteed that the supporting column is stably embedded into the sea; s2, a plurality of outer connecting steel plates are installed on the outer sides of the supporting columns and are installed together through connecting assemblies, and then inner connecting steel plates are spliced on the inner sides of the supporting columns; s3, the outer side of the outer connecting steel plate is sealed through a sealing assembly; s4, water between the outer connecting steel plate and the inner connecting steel plate is discharged through a water pump, and concrete is poured and waits for solidification; and S5, water in the inner connecting steel plates is discharged, the foundation is constructed, and cofferdam building is completed.

Description

Technical Field

[0001] The present application relates to the technical field of water conservancy engineering, and in particular to a construction method of a cofferdam dam. Background Art

[0002] A cofferdam is a temporary structure mainly used in water conservancy project construction. Its function is to enclose the water body and prevent water and soil from entering the construction site of the building, so as to drain water, excavate foundation pits, and build buildings within the cofferdam. The application range of cofferdams is wide, including the construction or repair of underwater buildings such as dams, bridge piers, and docks. In the construction of water conservancy projects, cofferdams have made important contributions to creating a dry and safe working environment. The embankment is a general term for waterproof and water-blocking structures. The embankment is built along the river channel, such as the Hongze Lake embankment; the dam is built to intercept the river channel, such as the Huaiyin Zhulong Dam.

[0003] The construction of cofferdams in the ocean is usually to improve the bottom support for building bridges. During construction, multiple connecting steel plates are spliced ​​together to form a hollow support layer, and then concrete is poured after drainage to complete the outer construction. However, in order to ensure the stability between the connecting steel plates, secondary processing is generally required, such as underwater welding. However, the difficulty of underwater construction is relatively high and the tolerance rate is large. Summary of the invention

[0004] In view of the deficiencies in the prior art, the purpose of this application is to provide a construction method for a cofferdam dam to solve the above-mentioned technical problems.

[0005] The above-mentioned object of the present application is achieved through the following technical solution: A construction method of a cofferdam dam comprises the following steps: S1. After determining the offshore construction location, lower the support column and ensure that the support column is stably embedded in the sea; S2, installing multiple external connection steel plates on the outside of the support column and installing them together through the connection assembly, and then splicing the internal connection steel plates on the inside of the support column; S3, sealing the outer side of the external connection steel plate by means of a sealing assembly; S4, use a pump to drain the water between the outer connecting steel plate and the inner connecting steel plate, pour concrete, and wait for solidification; S5. Drain the water in the inner connecting steel plate, then construct the foundation to complete the cofferdam construction.

[0006] By adopting the above technical solution, the support column is stably embedded in the sea, providing a solid foundation for the entire structure. The outer connecting steel plate and the inner connecting steel plate are tightly and firmly connected through the connecting assembly, and the sealing assembly is used to effectively prevent water from penetrating from the joints and gaps. Among them, the matching of the connecting flange and the connecting groove, the extrusion of the flexible rubber, and the setting of the flexible sealing strip and the reinforcement have greatly enhanced the sealing of the structure. The sealing effect is achieved through the self-contained sealing assembly and the pressure of the water. Compared with the existing technology that requires secondary processing, the effect is more convenient and the fault tolerance rate is lower.

[0007] Furthermore, the connecting component includes a connecting flange fixedly connected to one end of the external connecting steel plate and a connecting groove opened at the other end, the connecting flange and the connecting groove match each other, a flexible rubber is fixedly arranged inside the connecting groove, and a sealing component for preventing water from entering is arranged on the outside of the external connecting steel plate.

[0008] By adopting the above technical solution, during construction, the connecting flange at one end of the external connecting steel plate is inserted into the connecting groove opened on the other external connecting steel plate. At this time, the flexible rubber in the connecting groove squeezes the connecting flange, thereby improving its sealing performance.

[0009] Furthermore, a two-shaped groove is provided at one end of the inner connecting steel plate, and a matching two-shaped block is fixedly arranged at the other end.

[0010] By adopting the above technical solution, during construction, the two-shaped groove at one end of the inner connecting steel plate and the two-shaped block of another inner connecting steel plate are spliced ​​to complete the integrated construction.

[0011] Furthermore, the outer connecting steel plate extends a pair of outer docking plates toward one end of the inner connecting steel plate, and the inner connecting steel plate extends a pair of inner docking plates toward one side of the outer connecting steel plate. Plug-in blocks are fixedly provided on the ends close to each other and are staggered with each other. Through holes are vertically opened on the plug-in blocks. The outer connecting plate and the inner connecting plate are spliced ​​with each other through the plug-in blocks, and connecting rods are plugged into the plug-in blocks. The outer connecting plate and the inner connecting plate are arranged on the outside of the support column.

[0012] By adopting the above technical solution, during the construction process, the outer connecting plate on the outer connecting steel plate and the inner connecting plate on the inner connecting steel plate are spliced ​​together on the support column, spliced ​​together by staggered plug-in blocks, and then plugged into the through holes in the multiple groups of plug-in blocks from top to bottom through connecting rods, thereby improving the overall connectivity.

[0013] Furthermore, the sealing assembly includes a flexible sealing strip fixedly connected to one end of the outer side of the external connecting steel plate, a matching groove is provided on the other end of the outer side of the external connecting steel plate, and a reinforcement piece is provided on the flexible sealing strip.

[0014] By adopting the above technical solution, after completing the construction of the external connecting steel plate and the internal connecting steel plate, the flexible sealing strip will be squeezed into the groove on the other external connecting steel plate by water pressure, thereby improving the sealing of the outer external connecting steel plate and preventing water from entering through the gap of the external connecting steel plate.

[0015] Furthermore, the reinforcement member includes connecting columns extending from the flexible sealing strip, the connecting columns are provided in multiple groups and are all fixedly connected to the flexible sealing strip, and the groove is provided with connecting grooves matching the connecting columns.

[0016] By adopting the above technical solution, the water pressure will continuously squeeze the flexible sealing strip on the external connecting steel plate, allowing the connecting column to be inserted into the connecting groove on another external connecting steel plate, thereby improving the connectivity between the flexible sealing strip and the external connecting steel plate.

[0017] Furthermore, a friction ring is fixedly provided on the outer side of the connecting column, a matching friction groove is provided on the side wall of the connecting groove, the friction ring and the connecting column are integrally formed, and the connecting column and the friction ring are made of silicone or rubber.

[0018] By adopting the above technical solution and setting the friction ring and the friction groove, when the flexible sealing strip is continuously squeezed into the groove by the pressure of water, the friction ring on the connecting column will slowly be squeezed into the friction groove on the side wall of the connecting groove on the other external connecting steel plate. Since there is no other external force, the connecting column will stay firmly in the connecting groove, thereby further improving its stability.

[0019] Furthermore, an embedded plate is fixed below the outer connecting steel plate and the inner connecting steel plate, and the bottom of the embedded plate is sharp.

[0020] By adopting the above technical solution, the arrangement of the embedded plates can provide additional supporting force for the outer connecting plates and the inner connecting plates to be inserted into the underwater foundation.

[0021] Furthermore, an L-shaped plate is fixedly provided on the inner side of the inner connecting steel plate, and a reinforcement ring clamped on the L-shaped plate is provided on the inner side of the inner connecting steel plate.

[0022] By adopting the above technical solution and setting the reinforcement ring, additional support force will be provided for the internal connecting steel plates, while improving the integrity between the internal connecting steel plates.

[0023] Furthermore, an embedding groove is opened on the outer side of the inner connecting steel plate, and the embedding groove is arranged in multiple groups and evenly distributed on the inner connecting steel plate. An embedding block is fixedly arranged on the inner side of the outer connecting steel plate, and the embedding block is arranged in multiple groups and evenly distributed on the outer connecting steel plate.

[0024] By adopting the above technical solution, when pouring concrete between the outer connecting steel plate and the inner connecting steel plate, the embedding blocks arranged on the outer connecting steel plate and the embedding grooves provided on the inner connecting steel plate will fit the concrete better.

[0025] In summary, the present application includes the following beneficial technical effects: by stably embedding the support columns in the sea, a solid foundation is laid for the entire cofferdam structure, ensuring stability and safety during the construction process. The external connecting steel plate and the internal connecting steel plate are tightly and firmly connected through precisely designed connection components, which effectively improves the overall strength and durability of the structure. At the same time, the use of advanced sealing components, such as the precise matching of the connecting flange and the connecting groove, the extrusion seal of the flexible rubber, and the setting of the flexible sealing strip and reinforcement, successfully prevents the infiltration of water from the joints and gaps, greatly enhancing the waterproof performance of the structure. Compared with the prior art, this method can achieve excellent sealing effect without secondary processing, which not only improves construction efficiency but also reduces engineering costs. In addition, through the steps of pumping water, pouring concrete and waiting for it to solidify, the close fit between the cofferdam and the foundation is ensured, further improving the stability and service life of the structure. In summary, this method has multiple advantages such as stable structure, superior waterproof performance, high construction efficiency and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the overall structure in the embodiment; Figure 2 Schematic diagram of the structure of the inner and outer connecting steel plates and the inner connecting steel plates in the embodiment; Figure 3 yes Figure 2 Schematic diagram of the structure from another perspective.

[0027] Figure numerals: 1. Support column; 2. External connecting steel plate; 20. Connecting flange; 200. Connecting groove; 201. Flexible rubber; 21. Flexible sealing strip; 22. External connecting plate; 23. Plug-in block; 230. Through hole; 24. Connecting rod; 25. Connecting column; 26. Friction ring; 27. Groove; 28. Connecting groove; 3. Internal connecting steel plate; 31. Two-shaped groove; 32. Two-shaped block; 33. Internal connecting plate; 4. Reinforcement ring; 41. L-shaped plate; 42. Embedded plate. DETAILED DESCRIPTION

[0028] The present application is further described in detail below with reference to the accompanying drawings.

[0029] Example, see Figure 1 , Figure 2 as well as Figure 3First, after selecting the construction location at sea, the support columns 1 are sunk into the seabed to ensure that they are firmly fixed in the predetermined position to provide a stable support foundation for the subsequent cofferdam structure. Next, the outer connecting steel plates 2 and the inner connecting steel plates 3 are installed. The outer connecting steel plates 2 are installed one by one to the periphery of the support columns 1 and are tightly connected through special connecting components. At the same time, the inner connecting steel plates 3 are also spliced ​​on the inner side of the support columns 1, corresponding to the outer steel plates, and together constitute the main structure of the cofferdam.

[0030] Then, the outer side of the externally connected steel plate 2 is sealed by using a sealing assembly to ensure that seawater does not penetrate into the cofferdam through the gaps between the steel plates.

[0031] Subsequently, a pump is used to pump out the water between the outer connecting steel plate 2 and the inner connecting steel plate 3, and then concrete is poured in this space. The concrete will gradually solidify, further enhancing the strength and stability of the cofferdam structure.

[0032] Finally, after the water in the inner connecting steel plate 3 is also discharged, the foundation where the cofferdam is located is constructed. After the foundation construction is completed, the construction work of the entire cofferdam dam is also successfully completed.

[0033] The stable embedding of the support column 1 provides a solid foundation for the entire cofferdam. The outer connecting steel plate 2 and the inner connecting steel plate 3 are tightly connected through a precise connecting assembly. At the same time, the ingenious design of the sealing assembly effectively prevents water from penetrating. In particular, the precise matching of the connecting flange 20 and the connecting groove 27200, the extrusion sealing effect of the flexible rubber 201, and the setting of the flexible sealing strip 21 and the reinforcement greatly improve the sealing performance of the structure. This self-contained sealing assembly can automatically adjust and enhance the sealing effect under the pressure of water, and has higher efficiency and better sealing performance than the existing technology that requires secondary processing.

[0034] In this embodiment, the specific structure of the connection assembly includes a connection flange 20 fixedly connected to one end of the outer connection steel plate 2, and a connection groove 200 opened at the other end of the outer connection steel plate 2. The design of these two parts is complementary to each other, and the shape and size of the connection flange 20 are completely matched with the connection groove 200, so that they can be tightly combined together. In addition, a layer of flexible rubber 201 is fixedly arranged inside the connection groove 200, which plays an additional sealing and buffering role.

[0035] During construction, when two external connection steel plates 2 need to be connected together, it is only necessary to insert the connection flange 20 of one of the steel plates into the connection groove 200 of the other steel plate. During this process, the flexible rubber 201 in the connection groove 200 will be squeezed and closely fit on the surface of the connection flange 20, thereby forming an effective sealing layer to prevent moisture from penetrating from the connection.

[0036] This connection method is not only simple and fast, but also can ensure that the connection between the two outer connecting steel plates 2 is tight and firm. At the same time, due to the squeezing effect of the flexible rubber 201, the sealing performance of the connection is also greatly improved, making the entire cofferdam dam structure safer and more reliable.

[0037] In this embodiment, the design of the inner connecting steel plate 3 also focuses on the tightness and stability of the connection. Specifically, a two-shaped groove 31 is provided at one end of the inner connecting steel plate 3 to match a specific portion of another inner connecting steel plate 3. Correspondingly, a two-shaped block 32 that completely matches the shape and size of the two-shaped groove 31 is fixedly provided at the other end of the inner connecting steel plate 3.

[0038] During the construction process, when two inner connecting steel plates 3 need to be connected together, it is only necessary to accurately insert the two-shaped block 32 of one steel plate into the two-shaped groove 31 of the other steel plate. This splicing method is not only simple and convenient, but also can ensure that the two inner connecting steel plates 3 form a stable whole at the connection, thereby improving the strength and stability of the entire cofferdam dam structure. After the construction is completed, the extrusion of the external force further improves the stability of the entire set of inner connecting steel plates 3.

[0039] In this embodiment, a pair of outer butt joint plates are extended from the outer connecting steel plate 2 toward one end of the inner connecting steel plate 3, and a pair of inner butt joint plates are extended from the inner connecting steel plate 3 toward one side of the outer connecting steel plate 2. The plug-in blocks 23 are fixedly provided on the ends close to the outer connecting plate 22 and the inner connecting plate 33, and are staggered and distributed. Through holes 230 are vertically opened on the plug-in blocks 23. The outer connecting plate 22 and the inner connecting plate 33 are spliced ​​with each other through the plug-in blocks 23, and the connecting rods 24 are plugged into the plug-in blocks 23. The outer connecting plate 22 and the inner connecting plate 33 are arranged on the outside of the support column 1. During the construction process, the outer connecting plate 22 on the outer connecting steel plate 2 and the inner connecting plate 33 on the inner connecting steel plate 3 are spliced ​​with each other on the support column 1, spliced ​​together by staggering the plug-in blocks 23, and then plugged into the through holes 230 in the multiple groups of plug-in blocks 23 from top to bottom through the connecting rods 24, thereby improving the overall connectivity.

[0040] In this embodiment, the sealing assembly includes a flexible sealing strip 21 fixedly connected to one end of the outer side of the outer connecting steel plate 2, a matching groove 27 is provided on the other end of the outer side of the outer connecting steel plate 2, and a reinforcing member is provided on the flexible sealing strip 21. After the construction of the outer connecting steel plate 2 and the inner connecting steel plate 3 is completed, the flexible sealing strip 21 will be squeezed into the groove 27 on the other outer connecting steel plate 2 by water pressure, thereby improving the sealing of the outer connecting steel plate 2 and preventing water from entering through the gap of the outer connecting steel plate 2.

[0041] In this embodiment, the reinforcement member includes a connection column 25 extending from the flexible sealing strip 21, and the connection column 25 is provided in multiple groups and is fixedly connected to the flexible sealing strip 21. The groove 27 has a connection groove 28 matching the connection column 25. The water pressure will continuously squeeze the flexible sealing strip 21 on the external connection steel plate 2, and the connection column 25 will be inserted into the connection groove 28 on another external connection steel plate 2, so as to improve the connectivity between the flexible sealing strip 21 and the external connection steel plate 2.

[0042] In this embodiment, a friction ring 26 is fixedly arranged on the outside of the connecting column 25, and a matching friction groove is provided on the side wall of the connecting groove 28. The friction ring 26 and the connecting column 25 are integrally formed, and the connecting column 25 and the friction ring 26 are made of silicone or rubber. With the arrangement of the friction ring 26 and the friction groove, when the flexible sealing strip 21 is continuously squeezed into the groove 27 by the pressure of water, the friction ring 26 on the connecting column 25 will be slowly squeezed into the friction groove on the side wall of the connecting groove 28 on the other outer connecting steel plate 2. Since there is no other external force, the connecting column 25 will stay firmly in the connecting groove 28, thereby further improving its stability.

[0043] In this embodiment, an embedded plate 42 is fixed below the outer connecting steel plate 2 and the inner connecting steel plate 3, and the bottom of the embedded plate 42 is sharp. The arrangement of the embedded plate 42 can provide additional support for the outer connecting plate 22 and the inner connecting plate 33 to be inserted into the sea foundation.

[0044] In this embodiment, an L-shaped plate 41 is fixedly provided on the inner side of the inner connecting steel plate 3, and a reinforcement ring 4 is provided on the inner side of the inner connecting steel plate 3 and is clamped on the L-shaped plate 41. By setting the reinforcement ring 4, additional supporting force will be provided for the inner connecting steel plate 3, and at the same time, the integrity between the inner connecting steel plates 3 will be improved.

[0045] In this embodiment, an embedding groove is opened on the outer side of the inner connecting steel plate 3, and there are multiple groups of embedding grooves evenly distributed on the inner connecting steel plate 3. An embedding block is fixedly set on the inner side of the outer connecting steel plate 2, and there are multiple groups of embedding blocks evenly distributed on the outer connecting steel plate 2.

[0046] When pouring concrete between the outer connecting steel plate 2 and the inner connecting steel plate 3, the embedding blocks provided on the outer connecting steel plate 2 and the embedding grooves provided on the inner connecting steel plate 3 will make the concrete fit more closely to the outer connecting steel plate 2 and the inner connecting steel plate 3.

[0047] Specific implementation process: The cofferdam dam construction method first determines the offshore construction position, then lowers the support column 1 and ensures that it is stably embedded in the sea to provide a solid foundation for the entire structure. Next, multiple external connecting steel plates 2 are installed on the outside of the supporting column 1 and are tightly connected through connecting components (including connecting flanges 20, connecting grooves 200 and flexible rubber 201). At the same time, the internal connecting steel plate 3 is also spliced ​​on the inside of the supporting column 1, and the integrated construction is completed by splicing the two-character groove 31 and the two-character block 32. A sealing component is set on the outside of the external connecting steel plate 2, including a flexible sealing strip 21 and a reinforcement (connecting column 25, friction ring 26, etc.). These components are squeezed into the groove 27 of another external connecting steel plate 2 under the action of water pressure to achieve a sealing effect. After that, a pump is used to drain the water between the external connecting steel plate 2 and the internal connecting steel plate 3, and concrete is poured and waited for it to solidify to ensure a close fit between the concrete and the steel plate. Finally, the water in the internal connecting steel plate 3 is drained, and the foundation is constructed to complete the construction of the cofferdam dam.

[0048] The support column 1 is stably embedded in the sea, providing a solid foundation for the entire cofferdam structure. The outer connecting steel plate 2 and the inner connecting steel plate 3 are tightly and firmly connected through a precisely designed connection assembly, ensuring the overall stability of the structure. At the same time, the setting of the embedded plate 42 further enhances the bonding strength between the structure and the foundation in the sea, and improves the ability to resist wind and waves and scour.

[0049] The ingenious design of the sealing assembly, including the matching of the connecting flange 20 and the connecting groove 200, the extrusion seal of the flexible rubber 201, and the coordinated use of the flexible sealing strip 21 and the reinforcement, effectively prevents water from penetrating from the joints and gaps. In particular, the flexible sealing strip 21 is squeezed into the groove 27 of the other outer connecting steel plate 2 under the action of water pressure, and the connection column 25 and the connection groove 28 are closely matched, which greatly enhances the waterproof performance of the structure and ensures the safety and stability of the cofferdam in long-term use.

[0050] This construction method simplifies the construction process and improves the construction efficiency through standardized connection components and sealing components. The plugging of the connection flange 20 and the connection groove 200, the splicing of the two-shaped groove 31 and the two-shaped block 32, and the matching of the plug-in block 23 and the connecting rod 24 all make the construction process more convenient and efficient, reducing the time and cost of manual operation.

[0051] The embedded blocks arranged on the outer connecting steel plate 2 and the embedded grooves opened on the inner connecting steel plate 3 enable the poured concrete to better fit the steel plate, thus improving the integrity and stability of the structure. This design not only enhances the bond strength of the concrete, but also helps to improve the impermeability and durability of the cofferdam.

[0052] The embodiments of this specific implementation method are all preferred embodiments of the present application, and are not intended to limit the protection scope of the application. Therefore, all equivalent changes made based on the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A method for constructing a cofferdam dam, characterized in that: The following steps are involved: S1. After determining the offshore construction location, lower the support column (1) and ensure that the support column (1) is stably embedded in the sea; S2, installing a plurality of external connection steel plates (2) on the outside of the support column (1) and installing them together through a connection assembly, and then splicing the internal connection steel plates (3) on the inside of the support column (1); S3, sealing the outer side of the external connection steel plate (2) by means of a sealing assembly; S4, using a pump to drain the water between the outer connecting steel plate (2) and the inner connecting steel plate (3), pouring concrete, and waiting for solidification; S5, drain the water in the inner connecting steel plate (3), and then construct the foundation to complete the cofferdam construction.

2. A method for constructing a cofferdam dam according to claim 1, characterized in that: The connection assembly comprises a connection flange (20) fixedly connected to one end of the external connection steel plate (2) and a connection groove (200) opened at the other end, the connection flange (20) and the connection groove (200) match each other, a flexible rubber (201) is fixedly arranged inside the connection groove (200), and a sealing assembly for preventing water from entering is arranged on the outside of the external connection steel plate (2).

3. A method for constructing a cofferdam dam according to claim 2, characterized in that: One end of the inner connecting steel plate (3) is provided with a two-shaped groove (31), and the other end is fixedly provided with a matching two-shaped block (32).

4. A method for constructing a cofferdam dam according to claim 2, characterized in that: The outer connecting steel plate (2) extends a pair of outer docking plates toward one end of the inner connecting steel plate (3), and the inner connecting steel plate (3) extends a pair of inner docking plates toward one side of the outer connecting steel plate (2). The outer connecting plate (22) and the inner connecting plate (33) are fixedly provided with plug-in blocks (23) on their respective ends, and are staggered with each other. The plug-in blocks (23) are vertically provided with through holes (230). The outer connecting plate (22) and the inner connecting plate (33) are spliced ​​with each other through the plug-in blocks (23), and a connecting rod (24) is plugged into the plug-in blocks (23). The outer connecting plate (22) and the inner connecting plate (33) are arranged on the outside of the support column (1).

5. The construction method of a cofferdam dam according to claim 2, characterized in that: The sealing assembly comprises a flexible sealing strip (21) fixedly connected to one end of the outer side of the external connection steel plate (2), a matching groove (27) is provided on the other end of the outer side of the external connection steel plate (2), and a reinforcement piece is provided on the flexible sealing strip (21).

6. A method for constructing a cofferdam dam according to claim 5, characterized in that: The reinforcing member comprises a connecting column (25) extending from the flexible sealing strip (21), wherein the connecting columns (25) are provided in a plurality of groups and are all fixedly connected to the flexible sealing strip (21), and a connecting groove (28) matching the connecting column (25) is provided inside the groove (27).

7. A method for constructing a cofferdam dam according to claim 6, characterized in that: A friction ring (26) is fixedly arranged on the outside of the connecting column (25), a matching friction groove is provided on the side wall of the connecting groove (28), the friction ring (26) and the connecting column (25) are integrally formed, and the connecting column (25) and the friction ring (26) are made of silicone or rubber.

8. A method for constructing a cofferdam dam according to claim 5, characterized in that: An embedded plate (42) is fixed below the outer connecting steel plate (2) and the inner connecting steel plate (3), and the bottom of the embedded plate (42) is sharp.

9. A method for constructing a cofferdam dam according to claim 2, characterized in that: An L-shaped plate (41) is fixedly arranged on the inner side of the inner connecting steel plate (3), and a reinforcing ring (4) clamped on the L-shaped plate (41) is arranged on the inner side of the inner connecting steel plate (3).

10. A method for constructing a cofferdam dam according to claim 9, characterized in that: The outer side of the inner connecting steel plate (3) is provided with an embedding groove, and the embedding grooves are arranged in multiple groups and are evenly distributed on the inner connecting steel plate (3). The inner side of the outer connecting steel plate (2) is fixedly provided with an embedding block, and the embedding blocks are arranged in multiple groups and are evenly distributed on the outer connecting steel plate (2).

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