An assembly method for adding cantilevered steel structures to existing concrete beam-column joints

Abstract

This invention provides an assembly method for adding a cantilevered steel structure to an existing concrete beam-column joint; including: cleaning the surface of the existing concrete beam-column joint (1), and wrapping it with steel plates to form an outer steel sleeve (2); setting an upper stiffening steel plate (6) and a lower stiffening steel plate (7) inside a short steel square tube column (3); bolting and welding the cantilevered steel beam (5) to the short steel square tube column (3) in a factory processing workshop to form a whole; lifting the cantilevered steel beam (5) to the installation height, and welding the short steel square tube column (3) to the outer steel sleeve (2); injecting high-performance grout (4) into the short steel square tube column (3) through the reserved hole of the upper stiffening steel plate (7). This invention adds an outer steel sleeve to the existing beam-column joint, which enhances the load-bearing capacity of the existing beam-column joint without destroying its integrity and load-bearing capacity; this invention adopts a prefabricated connection, which has the advantages of convenient construction and reliable connection quality.

Description

Technical Field

[0001] This invention belongs to the field of construction; in particular, it relates to an assembly method for adding a cantilevered steel structure to an existing concrete beam-column joint. Background Technology

[0002] With the acceleration of urbanization in my country, how to revitalize old urban buildings and improve the city's image has become a major challenge. Urban renewal and renovation have become the mainstream direction of current urban construction. Diverse renovations of building facades have become commonplace in urban building renovation and upgrading. Typically, this is achieved by adding cantilevered steel structures to the facade.

[0003] The traditional approach to addressing this type of technical problem is to install rebar at the existing beam-column joint or to install anchor plates on the outer surface of the column. The traditional approach inevitably involves drilling holes at the existing beam-column joint for rebar installation, which has the following disadvantages: (1) Rebar installation or drilling will damage the integrity and load-bearing capacity of the existing beam-column joint; (2) The rebar at the existing beam-column joint is dense, and the location of rebar installation or drilling cannot be guaranteed; (3) The anchor plate is welded to the steel beam at high altitude, and the construction quality is difficult to guarantee; (4) The anchor plate is prone to local instability when bearing the load transmitted from the steel beam; (5) Due to the limitations of the number of rebars and the size of the anchor plate, the load-bearing capacity of the newly added cantilevered steel structure is limited.

[0004] Given the aforementioned technical shortcomings, there is an urgent need for a prefabricated connection method to solve these technical problems. Summary of the Invention

[0005] The purpose of this invention is to provide an assembly method for adding cantilevered steel structures to existing concrete beam-column joints.

[0006] This invention is achieved through the following technical solution:

[0007] This invention relates to an assembly method for adding a cantilevered steel structure to an existing concrete beam-column joint, comprising the following steps:

[0008] The first step is to clean and grind the surface decoration layer of the existing concrete beam-column joint 1, and then, based on the existing beam-column joint 1, use steel plates to wrap it to form an outer steel enclosure 2.

[0009] The second step is to manufacture steel square tube short columns 3 in the factory processing workshop, and to install upper stiffening steel plates 6 and lower stiffening steel plates 7 inside the steel square tube short columns 3, with the installation positions being at the same height as the upper and lower flanges of the steel beam;

[0010] The third step is to bolt and weld the cantilevered steel beam 5 to the short steel square tube column 3 in the factory processing workshop to form a whole;

[0011] The fourth step is to carry out hoisting and splicing on the construction site, lift the cantilever steel beam 5 to the installation height, and weld the steel square tube short column 3 to the outer steel casing 2.

[0012] Fifth step: inject high-performance grout 4 into the short steel square tube column 3 through the reserved hole of the upper stiffening steel plate 7.

[0013] Preferably, in the first step, the steel plate has a thickness of 2cm and is made of Q355B grade material.

[0014] Preferably, in the first step, the outer steel casing 2 adopts a single-sided bevel weld.

[0015] Preferably, in the second step, the height of the short steel square tube column 3 is 10cm greater than the height of the cantilever steel beam 5.

[0016] Preferably, in the fourth step, the surrounding weld is specifically a fillet weld.

[0017] Preferably, in the fourth step, the height of the weld seam of the surrounding weld is not less than 10mm.

[0018] The present invention has the following advantages:

[0019] (1) The present invention adds an outer steel sleeve to the existing beam-column joint, which enhances the load-bearing capacity of the existing beam-column joint without destroying the integrity and load-bearing capacity of the existing beam-column joint (the original joint becomes a steel-concrete joint).

[0020] (2) The size of the steel square tube short column set in this invention can be adjusted according to the bearing capacity required by the cantilever steel structure. If the load of the cantilever steel structure is large, the size of the steel square tube short column can be enlarged. As a result, the length of the fillet weld between the steel square tube short column and the outer steel sleeve of the column increases. The longer the weld length, the higher the bearing capacity.

[0021] (3) The method involved in this invention is based on the ingenious design of the force. When the cantilever steel beam is under stress, the load is first transferred to the steel square tube short column filled with high-performance grout. The steel square tube short column has good rigidity and strength compared with the steel plate and will not experience local pressure failure and instability.

[0022] (4) The present invention assembles and connects the new cantilever steel beam and the short steel square tube column in the factory and installs them on site, which reduces high-altitude operations and ensures reliable connection quality.

[0023] (5) The connection method proposed in this invention has a clever and clear force transmission path and a reliable connection. Attached Figure Description

[0024] Figure 1 This is a top view of the assembly of the present invention;

[0025] Figure 2 This is a front view of the assembly of the present invention;

[0026] Figure 3 This is a top view of the welding assembly of the present invention;

[0027] Figure 4 This is a welding front view of the assembly of the present invention;

[0028] The attached diagram is labeled as follows: 1 is the existing beam-column joint, 2 is the outer steel casing, 3 is the short steel square tube column, 4 is the high-performance grouting material, 5 is the cantilever steel beam, 6 is the upper stiffening steel plate, and 7 is the lower stiffening steel plate. Detailed Implementation

[0029] The present invention will now be described in detail with reference to specific embodiments. It should be noted that the following embodiments are merely further illustrations of the present invention, but the scope of protection of the present invention is not limited to the following embodiments.

[0030] Example

[0031] This embodiment relates to an assembly method for adding a cantilevered steel structure to an existing concrete beam-column joint, such as... Figures 1-4 As shown, it includes the following steps:

[0032] The first step is to clean and grind the surface decoration layer of the existing concrete beam-column joint 1. Then, based on the existing beam-column joint 1, a steel plate (2cm thick and Q355B grade) is used to wrap it to form an outer steel enclosure 2. The outer steel enclosure 2 adopts a single-sided bevel weld.

[0033] The second step is to manufacture steel square tube short columns 3 in the factory processing workshop, and install upper stiffening steel plates 6 and lower stiffening steel plates 7 inside the steel square tube short columns 3 (the height of which is 10cm greater than the height of the cantilever steel beam 5). The installation positions are the same as the upper and lower flanges of the steel beam.

[0034] The third step is to bolt and weld the cantilevered steel beam 5 to the short steel square tube column 3 in the factory processing workshop to form a whole;

[0035] The fourth step is to hoist and assemble the cantilevered steel beam 5 at the construction site, and then weld the steel square tube short column 3 to the outer steel casing 2 with fillet welds (the weld height shall not be less than 10mm).

[0036] Fifth step: inject high-performance grout 4 into the short steel square tube column 3 through the reserved hole of the upper stiffening steel plate 7.

[0037] Compared with existing technologies, this invention has the following advantages: This invention adds an outer steel sleeve to the existing beam-column joint, enhancing its load-bearing capacity without compromising its integrity or load-bearing capacity (the original joint becomes a steel-concrete joint); the method involved in this invention, based on a clever force design, first transfers the load to the steel square tube short column filled with high-performance grout when the cantilever steel beam is under load. The steel square tube short column has better rigidity and strength than steel plate, preventing localized compression failure and instability. This invention assembles and connects the new cantilever steel beam and steel square tube short column in the factory, then hoists and installs them on-site, minimizing high-altitude work and ensuring reliable connection quality; the connection method proposed in this invention has a clever and clear force transmission path, resulting in a reliable connection.

[0038] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various modifications or variations within the scope of the claims, which do not affect the essence of the present invention.

Claims

1. An assembly method for adding a new cantilever steel structure to an existing concrete beam-column joint, characterized in that, The method comprises the following steps: Firstly, clean the surface decoration layer of the existing concrete beam-column joint (1), and then use a steel plate to form an outer steel sleeve (2) by wrapping the existing beam-column joint (1); Secondly, manufacture a steel square tube stub column (3) in a factory workshop, and set an upper stiffening steel plate (6) and a lower stiffening steel plate (7) in the steel square tube stub column (3); Thirdly, connect the cantilever steel beam (5) and the steel square tube stub column (3) by bolting and welding in the factory workshop to form an integral whole; Fourthly, hoist and splice the cantilever steel beam (5) to the installation height, and then perform surrounding welding between the steel square tube stub column (3) and the outer steel sleeve (2) on the construction site; Fifthly, fill the steel square tube stub column (3) with high-performance grouting material (4) through the reserved hole of the lower stiffening steel plate (7); In the second step, the height of the steel square tube stub column (3) is 10 cm greater than the height of the cantilever steel beam (5).

2. The method of claim 1, wherein the method further comprises: In the first step, the thickness of the steel plate is 2 cm, and the material is Q355B grade.

3. The method of claim 1, wherein the method further comprises: In the first step, the outer steel sleeve (2) adopts a single-sided bevel weld.

4. The method of claim 1, wherein the method further comprises: In the fourth step, the surrounding welding is specifically performed by using an angle weld.

5. The method of claim 1, wherein the method further comprises: In the fourth step, the weld height of the surrounding welding is not less than 10 mm.

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