After-loading construction method for buckling restrained brace system in confined space

Abstract

The invention provides a post-installation construction method for a buckling restrained brace system in a confined space, which comprises the following steps: S1, pre-burying a bracket mounting piece and two hoisting hanging rings in a cross beam of an upper floor slab, reserving holes in the positions of the floor slab on two sides of the bracket mounting piece, and arranging a first chain block above the holes; s2, the two first chain blocks penetrate through the corresponding holes, the two sides of a bracket are hoisted correspondingly, the bracket is hoisted to the position below the bracket mounting piece, and the bracket is connected with the bracket mounting piece; and S3, second chain blocks are arranged on the two hoisting hanging rings correspondingly, the two second chain blocks hoist the two buckling restrained braces correspondingly, the upper ends of the buckling restrained braces and the corresponding connecting ends of the brackets are installed, and the lower ends of the buckling restrained braces and the corresponding steel columns are installed. Convenience is provided for installation of components of the buckling restrained brace system in the limited space.

Description

Technical Field

[0001] The present invention relates to the technical field of steel structure construction, and more particularly to a post-installation construction method of a buckling restrained brace system in a confined space. Background Art

[0002] With the continuous progress of society, people have higher and higher requirements for the quality of buildings used in production and life. As an important indicator to measure the quality of a building, earthquake resistance is valued by people. The buckling restrained brace (BRB, full name Buckling Restrained Brace) has a clear shock absorption mechanism and obvious shock absorption effect. It is safe, reliable and economical. It can be used in structures with different earthquake intensities and seismic resistance requirements. It can also provide great lateral stiffness and bearing capacity for frame or rack structures. Buckling restrained brace structural systems have been widely used in building structures. In building structures, buckling restrained brace members are not only set in locations where conventional construction methods and lifting machinery can be used for construction, but also some are set in confined space environments such as basements, which are difficult to construct using conventional construction methods. Summary of the Invention

[0003] In view of the above problems, the purpose of the present invention is to provide a post-installation construction method for a buckling restrained brace system in a confined space, which is used in confined spaces such as basements where conventional installation machinery cannot be used for post-installation buckling restrained brace construction. By utilizing a preset fall chain for hoisting and installation, labor and machinery input are reduced, thereby facilitating the installation of components of the buckling restrained brace system in a confined space.

[0004] The present invention provides a post-installation construction method for a buckling restrained brace system in a confined space, comprising the following steps:

[0005] S1: Embed a corbel mounting member and two lifting rings in the beam of the upper floor slab to be connected to the buckling restrained brace system. The corbel mounting member is located between the two lifting rings. Holes are reserved in the floor slab on both sides of the corbel mounting member, and a first fall chain is installed above the holes.

[0006] S2: The two first fall chains are passed through the corresponding holes and hoisted on both sides of the corbel respectively, the corbel is hoisted below the corbel mounting piece, and the corbel is connected to the corbel mounting piece;

[0007] S3: A second fall chain is set on each of the two lifting rings, and the two second fall chains respectively lift the two buckling restraint supports of the buckling restraint support system, and install the upper end of the buckling restraint support with the corresponding connecting end of the corbel, and install the lower end of the buckling restraint support with the corresponding steel column.

[0008] An optional solution is to install the two steel columns respectively between the beam to be cast and the floor before step S1.

[0009] Among them, an optional solution is that in step S1, a corbel mounting part and two lifting rings are embedded in the beam of the upper floor slab to which the buckling restraint support system is to be connected, including: embedding the corbel mounting part in the middle position of the beam between the two steel columns; calculating the center of gravity position of the buckling restraint support after installation, and the embedded position of the lifting ring is in the same vertical direction as the center of gravity position.

[0010] Among them, an optional solution is that in step S1, holes are reserved at the floor positions on both sides of the corbel mounting member, and a first fall chain is set above the hole, including: setting the hole in the middle position of the two steel columns, the distance between the edges of the two holes and the adjacent beam side walls is the same, and a horse stool spanning the hole is set at the upper part of the hole, and the first fall chain is connected to the horse stool.

[0011] Among them, an optional solution is that the horse stool includes two support rods and a cross bar connected between the upper ends of the two support rods, the lower ends of the support rods are connected to the middle of the support plate, and both ends of the support plate are connected to the support rods with reinforcing rods, and the two support plates are respectively fixed above the edges of the opening perpendicular to the cross beam.

[0012] Among them, an optional solution is that in step S2, the two first fall chains pass through the corresponding holes and are respectively hoisted on both sides of the corbel, including: connecting the connecting hooks of the two first fall chains to the connecting parts on both sides of the upper part of the corbel, and the two first fall chains synchronously hoist the corbel to the bottom of the corbel mounting part.

[0013] Among them, an optional solution is that the connecting member includes a middle ear plate arranged on the upper side of the corbel and a steel rope connected to the ear plate, and the steel rope is connected to the connecting hook of the first fall chain.

[0014] Among them, an optional solution is that in step S3, a second fall chain is set on the two lifting rings, and the two second fall chains respectively lift the two buckling restraint supports of the buckling restraint support system, including: hanging the two second fall chains on the two lifting rings respectively, connecting the connecting hooks of the second fall chains with the hanging parts on the buckling restraint support, and lifting the buckling restraint support until the upper and lower ends of the buckling restraint support are aligned with the corresponding connecting ends of the corbel and the installation ends of the corresponding steel columns respectively.

[0015] Among them, an optional solution is that the hanging part includes two lifting ears arranged on the buckling restraint support, the two lifting ears are equidistant from the center of gravity of the buckling restraint support, a steel wire rope is connected between the two lifting ears, the connecting hook of the second fall chain lifts the steel wire rope, and at the same time adjusts the angle of the buckling restraint support to lift the buckling restraint support into place.

[0016] Among them, an optional solution is that the lifting ring includes a square steel plate and a lifting ring welded to the lower middle part of the square steel plate, inverted L-shaped steel bars are evenly welded above the square steel plate, the inverted L-shaped steel bars are pre-embedded in the beam, and the lifting ring is exposed on the lower side of the beam; the lifting ring includes an arc-shaped steel bar, and horizontal steel bars are connected to both ends of the arc-shaped steel bar, and the horizontal steel bar is welded to the square steel plate.

[0017] As can be seen from the above description, the post-installation construction method of the buckling restrained brace system in a confined space provided by the present invention includes hoisting the corbel through a first fall chain suspended from a reserved opening in the upper floor slab to facilitate the installation of the corbel with the corbel mounting member embedded in the beam of the upper floor slab, and connecting the second fall chain through a hoisting ring embedded in the beam to hoist the buckling restrained brace, thereby facilitating the installation of the buckling restrained brace. The present invention sets the hanging point of the fall chain in a limited space, hoists and installs each buckling restrained brace member, avoids the use of large-scale mechanical equipment, ensures both proper installation and installation quality, improves the installation rate of the post-installed buckling restrained brace system in a limited space, and saves costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] By referring to the following description in conjunction with the accompanying drawings, and with a more complete understanding of the present invention, other objects and results of the present invention will become more apparent and easier to understand. In the accompanying drawings:

[0019] Figure 1 Flowchart of a post-installation construction method of a buckling restrained brace system in a confined space according to an embodiment of the present invention;

[0020] Figure 2 Schematic diagram of the structure of a post-installation construction method of a buckling restrained brace system in a confined space according to an embodiment of the present invention;

[0021] Figure 3 A schematic diagram of the hoisting of a buckling restrained brace according to an embodiment of the present invention;

[0022] Figure 4 A schematic structural diagram of a horse stool according to an embodiment of the present invention;

[0023] Figure 5 A side view of a horse stool according to an embodiment of the present invention;

[0024] Figure 62. It is a structural diagram of a hoisting ring according to an embodiment of the present invention;

[0025] Figure 7 A top view of a hanging ring according to an embodiment of the present invention;

[0026] Among them, 1-opening, 2-lifting ring, 21-square steel plate, 22-lifting ring, 221-arc-shaped steel bar, 222-cross steel bar, 23-inverted L-shaped steel bar, 3-first fall chain, 4-second fall chain, 5-stool, 51-cross bar, 52-support bar, 53-support plate, 54-reinforcement bar, 6-connector, 61-ear plate, 62-steel rope, 7-hanging fixture, 71-lifting ear, 72-steel wire rope, 8-buckling restraint support system, 81-corbel, 82-buckling restraint support, 83-steel column, 84-corbel mounting parts, 9-crossbeam;

[0027] The same reference numerals throughout the drawings indicate similar or corresponding features or functions. DETAILED DESCRIPTION

[0028] The present invention is susceptible to various modifications and embodiments, and specific embodiments are illustrated and described with reference to the accompanying drawings. However, the present invention is not limited to these specific embodiments and encompasses all modifications, equivalents, and alternatives falling within the spirit and technical scope of the present invention, and should be understood to be encompassed thereby.

[0029] Ordinal terms such as first and second may be used to describe various components, but the components are not limited to these terms. These terms are used only to distinguish one component from another. For example, the second component may be named the first component, and similarly, the first component may be named the second component without departing from the scope of the claims of the present invention. Terms and / or terms include a combination of multiple related items or a specific item from multiple related items.

[0030] It should be understood that when a component is referred to as being "connected" or "in contact with" another component, this includes not only being directly connected or in contact with the other component, but also being understood to include being interposed with other components. Conversely, when a component is referred to as being "directly connected" or "directly in contact with" another component, it should be understood that there are no interposed components.

[0031] In the description of the embodiments, when a component is described as being formed "on or under" another component, "on or under" includes both components being in direct contact with each other or at least one other component being disposed between the two components. Furthermore, when "on" or "under" is used as a reference, it refers not only to the upper direction but also to the lower direction.

[0032] The terms used in this application are only used to illustrate specific embodiments and are not intended to limit the present invention. Unless the context clearly dictates otherwise, expressions in the singular include expressions in the plural. In this application, it should be understood that terms such as "including" or "having" are used to specify the presence of features, numbers, steps, operations, constituent elements, parts, or combinations thereof described in the specification, and do not preclude the presence or additional possibility of one or more other features, numbers, steps, operations, constituent elements, parts, or combinations thereof.

[0033] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meanings as those generally understood by those skilled in the art. Terms defined in commonly used dictionaries should be interpreted as having the same meanings as those in the context of the relevant technology and should not be interpreted as having ideal or overly formal meanings unless they are clearly defined in this application.

[0034] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0035] Glossary:

[0036] Buckling Restrained Brace (BRB): It consists of a core material, an outer sleeve, and an unbonded material within the sleeve. This bracing structure prevents the buckling that commonly occurs in ordinary steel braces under compression, thereby improving the seismic performance of the structure. A buckling-restrained brace can yield in both tension and compression, exhibiting excellent energy dissipation capacity and stable mechanical properties. Its application can comprehensively improve the seismic performance of traditional braced frames in moderate and severe earthquakes. A buckling-restrained brace system is a bracing structure composed of buckling-restrained brace members.

[0037] like Figure 1 As shown, the post-installation construction method of the buckling restrained brace system in a confined space proposed in this embodiment can be used for the post-installation construction of the buckling restrained brace system in a small space such as a basement, and can also be used for the post-installation of the buckling restrained brace system in other occasions where conventional installation machinery cannot be used for conventional post-installation methods.

[0038] The post-installation construction method of the buckling restrained brace system in a confined space comprises the following steps:

[0039] S1: A corbel mounting member 84 and two lifting rings 2 are embedded in the beam 9 of the upper floor slab to be connected to the buckling restraint support system 8. The corbel mounting member 84 is located between the two lifting rings 2. Openings 1 are reserved in the floor slabs on both sides of the corbel mounting member 84, and a first fall chain 3 is set above the opening 1.

[0040] Before casting the upper crossbeam 9, the buckling restraint brace system 8 is laid out, and the positions of the corbel mounting members 84 and the two lifting eyelets 2 in the crossbeam 9 are calculated. The corbel mounting members 84 and the two lifting eyelets 2 are respectively fixed to appropriate positions in the casting template of the crossbeam 9. Then, casting is performed so that the corbel mounting members 84 and the two lifting eyelets 2 are pre-embedded in the crossbeam 9, and the mounting ends of the corbel mounting members 84 and the loops of the lifting eyelets 2 are exposed on the underside of the crossbeam 9, facilitating the installation of the corbel 81 and the lifting of the buckling restraint brace 82.

[0041] A typical buckling-restrained brace system 8 comprises a vertical steel column 83 at each end of a beam 9. A corbel 81 has two symmetrical branches, and two buckling-restrained braces 82 are connected between the branches of the corbel 81 and the lower ends of the adjacent steel columns. The two buckling-restrained braces 82 are symmetrical about the midplane between the two steel columns 83. Prior to step S1, the two steel columns 83 are installed between the beam 9 to be cast and the floor. Before casting the beam 9, the steel columns 83 are pre-connected to the beam 9's steel reinforcement formwork. After casting, the beam 9 is securely fastened to the steel columns 83. The steel columns 83 can be structural columns.

[0042] In this embodiment, the corbel mounting member 84 can be pre-embedded in the middle position of the crossbeam 9 between the two steel columns 83 to facilitate the symmetry of the two flexure restraint supports 82; the specific setting method of the position of the lifting ring 2 can be to calculate the center of gravity position of the flexure restraint support 82 after installation, and the pre-embedded position of the lifting ring 2 is in the same vertical direction as this center of gravity position. After the lifting ring 2 is pre-embedded, it should be aligned up and down with this center of gravity position to facilitate lifting the flexure restraint support 82 to a suitable angle.

[0043] Before pouring the upper floor slab, a square opening is reserved on the floor slab formwork on both sides of the beam 9 according to the layout position of the corbel mounting member 84. The square opening is aligned with the center of the corbel mounting member 84, and then poured to form the opening 1. The first fall chain 3 hanging from the two openings 1 can be used to balance the lifting of both sides of the corbel 81 to be installed, so that the corbel 81 and the corbel mounting member 84 are firmly connected.

[0044] In this embodiment, in order to balance the lifting corbel 81, the opening 1 can be set in the middle position of the two steel columns 83, and the distance between the edges of the two openings 1 and the adjacent side walls of the beam is the same. There can be a slight gap between the edge of the opening 1 and the side wall of the beam 9 to facilitate the connection between the two first fall chains 3 and the corbel 81.

[0045] In order to facilitate the installation of the first fall chain 3, a horse stool 5 is set across the opening 1 at the upper part of the opening 1, and the first fall chain 3 is connected to the horse stool 5. The horse stool 5 installed at the opening 1 hangs the first fall chain 3 above the upper floor and in the middle of the opening 1. There is enough rising space to facilitate the lifting of the corbel 81 into place.

[0046] In this embodiment, to ensure stable hoisting, the horse stool 5 may include two support rods 52 and a crossbar 51 connected between the upper ends of the two support rods 52. The lower ends of the support rods 52 are connected to the middle of a support plate 53. The support plate 53 is perpendicular to the crossbar 51. Reinforcement rods 54 are connected between each end of the support plate 53 and the support rods 52. The two support plates 53 are respectively fixed above the two sides of the opening 1 perpendicular to the crossbeam 9. The two support plates 53 can stably fix the horse stool 5 in the upper part of the opening 1. The reinforcement rods 54 can strengthen the stability of the horse stool 5. The first fall chain 3 is installed in the middle of the crossbar 51 and can be lowered to hoist the corbel 81. The support rods 52 and the crossbar 51 can both be made of I-beams.

[0047] In this embodiment, four lifting points are provided on the building structure body, so that the lifting of all components of the buckling restrained support system 8 can be completed, eliminating the use of large machinery and ensuring stable and safe lifting.

[0048] S2: The two first fall chains 3 pass through the corresponding openings 1 and are hoisted on both sides of the corbel 81 respectively. The corbel 81 is hoisted below the corbel mounting piece 84 and connected to the corbel mounting piece 84 .

[0049] After all four hoisting points are set, the components are installed one by one. First, the bracket 81 is hoisted. The two first fall chains 3 can hoist the bracket 81 in a balanced manner.

[0050] To ensure a stable lifting connection, connectors 6 are provided on both sides of the corbel 81. The connecting hooks of the two first fall chains 3 are connected to the connectors 6 on the upper sides of the corbel 81. The two first fall chains 3 are hoisted simultaneously, keeping the corbel 81 vertical, and hoisted below the corbel mounting member 84. The hoisting height of the two first fall chains 3 should be kept at the same level. The corbel 81 is hoisted and balanced below the corbel mounting member 84. Then, the corbel 81 is mounted on the corbel mounting member 84. The two first fall chains 3 can be removed.

[0051] In this embodiment, the connecting member 6 may include a lug plate 61 disposed in the middle of the upper side of the corbel 81 and a steel rope 62 connected to the lug plate 61. The steel rope 62 is connected to the connecting hook of the first fall chain 3. The steel rope 62 connected through the lug plate 61 facilitates a stable connection with the connecting hook of the first fall chain 3 and facilitates balanced lifting.

[0052] S3: A second fall chain 4 is set on each of the two lifting rings 2. The two second fall chains 4 respectively lift the two buckling restraint supports 82 of the buckling restraint support system 8, and install the upper ends of the buckling restraint supports 82 with the corresponding connecting ends in the corbels 81, and install the lower ends of the buckling restraint supports 82 with the corresponding steel columns 83.

[0053] After the bracket 81 is installed, the buckling restraining brace 82 is installed. The two buckling restraining braces 82 can be installed at the same time or one by one.

[0054] The buckling restraint support 82 is hoisted from a placement position to an installation position using a second fall chain 4 for easy installation. Specifically, two second fall chains 4 can be hung on two hoisting rings 2, and the connecting hooks of the second fall chains 4 can be connected to the hangers 7 on the buckling restraint support 82. The buckling restraint support 82 can be hoisted until the upper and lower ends of the buckling restraint support 82 are aligned with the corresponding connection ends of the corbel 81 and the corresponding installation ends of the steel column 83. The second fall chain 4 is aligned with the center of gravity of the buckling restraint support 82 in the installation position, and the buckling restraint support 82 can be hoisted from the ground. During the hoisting process, the angle of the buckling restraint support 82 is adjusted until the tilt angle matches the installation angle. The second fall chain 4 can stably hoist the buckling restraint support 82 and maintain the angle, facilitating the installation of the two ends of the buckling restraint support 82.

[0055] In this embodiment, the hanger 7 includes two lifting lugs 71 disposed on the buckling-restraining support 82. The two lifting lugs 71 are equidistant from the center of gravity of the buckling-restraining support 82. A steel wire rope 72 is connected between the two lifting lugs 71, and the connecting hook of the second fall chain 4 is used to lift the steel wire rope 72. The buckling-restraining support 82, which is placed flat on the ground, is balanced and lifted by the second fall chain 4. The hanging position of the steel wire rope 72 on the connecting hook of the second fall chain 4 is gradually adjusted to gradually angle the buckling-restraining support 82, thereby lifting the buckling-restraining support 82 into place.

[0056] In this embodiment, in order to stably lift the flexure restraint support 82, the lifting ring 2 may include a square steel plate 21 and a lifting ring 22 welded to the lower middle part of the square steel plate 21, and inverted L-shaped steel bars 23 are evenly welded above the square steel plate 21. The inverted L-shaped steel bars are pre-embedded in the beam 9, and the lifting ring 22 is exposed on the lower side of the beam 9.

[0057] The inverted L-shaped steel bars 23 on the square steel plate 21 can be tied or welded to the steel bars in the crossbeam 9 and cast into the crossbeam 9, making the lifting ring 2 more stable and more resistant to tension. The square steel plate 21 can be flush with the lower side of the crossbeam 9, and the lifting ring 22 is below the crossbeam 9 to facilitate the connection of the second fall chain 4.

[0058] In order to stably connect the second fall chain 4, the lifting ring 22 includes an arc-shaped steel bar 221, and transverse steel bars 222 are connected to both ends of the arc-shaped steel bar 221. The transverse steel bars 222 are welded to the square steel plate 21. The semicircular arc-shaped steel bar 221 is firmly welded to the square steel plate 21 through the transverse steel bars 222 at both ends. The welding area is large and the tensile strength is stronger.

[0059] In this embodiment, the specifications of the fall chain are determined according to the construction conditions.

[0060] The above describes, by way of example, the post-installation construction method for a buckling-restrained brace system for confined spaces according to the present invention with reference to the accompanying drawings. However, those skilled in the art will appreciate that various modifications may be made to the post-installation construction method for a buckling-restrained brace system for confined spaces proposed herein without departing from the scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A post-installation construction method for a buckling restrained brace system in a confined space, characterized in that: The following steps are involved: S1: Embed a corbel mounting member and two lifting rings in the beam of the upper floor slab to be connected to the buckling restrained brace system, reserve openings in the floor slab on both sides of the corbel mounting member, and install a first fall chain above the openings; wherein the corbel mounting member is located between the two lifting rings; S2: The two first fall chains are passed through the corresponding holes and hoisted on both sides of the corbel respectively, the corbel is hoisted below the corbel mounting piece, and the corbel is connected to the corbel mounting piece; S3: A second fall chain is set on each of the two lifting rings, and the two second fall chains respectively lift the two buckling restraint supports of the buckling restraint support system, and install the upper end of the buckling restraint support with the corresponding connecting end of the corbel, and install the lower end of the buckling restraint support with the corresponding steel column.

2. The post-installation construction method of the buckling restrained brace system in a confined space according to claim 1, characterized in that: Before step S1, the method further includes: installing the two steel columns respectively between the beam to be cast and the floor.

3. The post-installation construction method of the buckling restrained brace system in a confined space according to claim 2, characterized in that: Embed bracket mounting parts and two lifting rings in the beams of the upper floor slab to which the buckling restrained bracing system is to be connected, including: Embed the corbel mounting piece in the middle of the beam between the two steel columns; The center of gravity position of the buckling restraint support after installation is calculated, and the embedded position of the hanging ring is in the same vertical direction as the center of gravity position.

4. The post-installation construction method of the buckling restrained brace system in a confined space according to claim 2, characterized in that: Holes are reserved at the floor positions on both sides of the corbel mounting member, and a first fall chain is arranged above the holes, including: The opening is set in the middle position of the two steel columns, the distance between the edges of the two openings and the adjacent side walls of the beam are the same, a horse stool spanning the opening is set on the upper part of the opening, and the first fall chain is connected to the horse stool.

5. The post-installation construction method of the buckling restrained brace system in a confined space according to claim 4, characterized in that: The horse stool includes two support rods and a cross bar connected between the upper ends of the two support rods. The lower ends of the support rods are connected to the middle of the support plate. Reinforcing rods are connected between the two ends of the support plate and the support rods. The two support plates are respectively fixed above the edges of the opening that are perpendicular to the cross beam.

6. The post-installation construction method of the buckling restrained brace system in a confined space according to claim 1, characterized in that: The two first fall chains pass through the corresponding holes and are respectively hoisted on both sides of the corbel, including: The connecting hooks of the two first fall chains are respectively connected to the connecting pieces on both sides of the upper part of the corbel, and the two first fall chains synchronously lift the corbel to the bottom of the corbel mounting piece.

7. The post-installation construction method of the buckling restrained brace system in a confined space according to claim 6, characterized in that: The connecting member includes a middle ear plate arranged on the upper side of the corbel and a steel rope connected to the ear plate, and the steel rope is connected to the connecting hook of the first fall chain.

8. The post-installation construction method of the buckling restrained brace system in a confined space according to claim 1, characterized in that: A second fall chain is provided on each of the two hoisting rings, and the two second fall chains are respectively used to hoist two buckling restrained supports of the buckling restrained support system, including: Hang the two second fall chains on the two lifting rings respectively, connect the connecting hooks of the second fall chains to the hanging pieces on the buckling restraint support, and lift the buckling restraint support until the upper and lower ends of the buckling restraint support are aligned with the corresponding connecting ends of the corbel and the installation ends of the corresponding steel columns respectively.

9. The post-installation construction method of the buckling restrained brace system in a confined space according to claim 8, characterized in that: The hanging piece includes two lifting ears arranged on the buckling restraint support, and the distance between the two lifting ears and the center of gravity of the buckling restraint support is equal. A steel wire rope is connected between the two lifting ears. The connecting hook of the second fall chain lifts the steel wire rope and adjusts the angle of the buckling restraint support at the same time to lift the buckling restraint support into place.

10. The post-installation construction method of the buckling restrained brace system in a confined space according to claim 1, characterized in that: The hoisting ring includes a square steel plate and a hoisting ring welded to the lower middle portion of the square steel plate, inverted L-shaped steel bars are evenly welded above the square steel plate, the inverted L-shaped steel bars are pre-embedded in the beam, and the hoisting ring is exposed on the lower side of the beam; The lifting ring includes an arc-shaped steel bar, and transverse steel bars are connected to both ends of the arc-shaped steel bar, and the transverse steel bars are welded to the square steel plate.

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