A reinforced concrete hanging column anchoring structure and construction method thereof

Abstract

The invention discloses a reinforced concrete column anchoring structure, and based on the structure, provides a reinforced concrete column anchoring construction method, which, when pouring a floor slab, reserves a pouring hole on the floor slab, and anchors the two ends of the outwardly expanded steel bars into the floor slab around the pouring hole; the column steel bar cage or the prefabricated column is hooked and / or welded to the floor slab steel bars; formwork support is performed on the periphery of the column steel bar cage to form a column pouring cavity; or, formwork support is performed on the periphery of the prefabricated column root to form a column root pouring cavity; concrete is poured into the column pouring cavity or the column root pouring cavity and the pouring hole through the pouring hole and vibrated; after the concrete pouring is completed, the column anchoring is completed; the problems of hollowing and cracking at the root of the reinforced concrete column are solved; the construction operation is simple and convenient, there is no difficulty in pouring, and there is no problem of difficulty in compacting by vibration, no safety hazards are left, the construction cost is relatively low, and it is suitable for promotion and application.

Description

Technical Field

[0001] The invention relates to a reinforced concrete hanging column anchoring structure and a construction method thereof, belonging to the technical field of building engineering design and construction. Background Art

[0002] In housing construction, especially in public buildings such as commercial, office, and hotel buildings, there are usually some transparent and open spaces in the lower part due to the requirements of building functions or building shapes. Therefore, it is not allowed to set columns to support the shapes, partitions, and mezzanines above the open space. In this case, it is necessary to add hanging columns and hanging beams on the upper floor of the open space to jointly support these shapes, partitions, and mezzanines. Figure 1 shown.

[0003] There are two materials to choose from for the columns and beams installed in the above projects: one is steel structure and the other is reinforced concrete. Steel structure columns and beams are generally used in pure steel structure projects or curtain wall related locations, and the cost is relatively high. If they are used in reinforced concrete projects, there are problems such as the difficulty of constructing embedded parts and post-embedded parts, and the difficulty in ensuring safety. Reinforced concrete columns and beams can be used in projects other than pure steel structure projects. Due to mature technology, convenient material acquisition and relatively low cost, reinforced concrete columns and beams are more widely used and more commonly used. However, since reinforced concrete columns are often constructed twice, their roots are below existing components. It is necessary to cast them on the side of the column roots after the template is partially expanded at the root of the column. Figure 2 As shown in the figure, it is very inconvenient for construction workers to operate under the floor slab, and there are difficulties in pouring and compaction through vibration, which may easily leave safety hazards. At the same time, the root of the reinforced concrete column is at the part with the greatest force. If the pouring quality of concrete at the root of the column is not good, it will easily cause hollowing, cracking and other problems in the later stage, affecting the appearance and the use of the owner, and the risk of safety hazards will increase. Figure 3 shown. Summary of the invention

[0004] In order to solve the problems of hollowing and cracking at the root of reinforced concrete columns, the present invention provides a reinforced concrete column anchoring structure, and based on the structure, provides a reinforced concrete column anchoring construction method, which solves the problems of hollowing and cracking at the root of reinforced concrete columns, and effectively improves the casting quality and the bearing capacity of the reinforced concrete columns. The construction operation is simple and convenient, there is no difficulty in casting, and there is no difficulty in compacting by vibration, no safety hazards will be left, the construction cost is relatively low, and it is suitable for promotion and application.

[0005] The first part of the present invention:

[0006] In order to solve the problems of hollowing and cracking at the root of reinforced concrete hanging columns, the present invention provides a reinforced concrete hanging column anchoring structure, comprising:

[0007] Pouring holes are reserved and set on the floor slab;

[0008] A hanging column is arranged below the pouring hole, and an outward expansion steel bar is arranged at the root of the hanging column to expand the size of the root of the hanging column, and both ends of the outward expansion steel bar are anchored in the floor slab around the pouring hole;

[0009] Concrete is poured at the base of the hanging column and in the pouring holes.

[0010] Preferably, the outwardly expanded steel bars are in an inverted "J"-shaped structure.

[0011] Furthermore, a plurality of the outwardly expanded steel bars are provided, and the plurality of outwardly expanded steel bars are divided into two groups, and the two groups of outwardly expanded steel bars are arranged perpendicularly and crosswise to each other, thereby improving the structural strength of the expanded part at the root of the hanging column.

[0012] Preferably, the longitudinal reinforcement of the suspension column at the root of the suspension column extends upward into the pouring hole of the floor slab and is bent and then hooked and / or welded to the floor slab reinforcement; so that the longitudinal reinforcement of the suspension column at the root of the suspension column is effectively connected to the floor slab reinforcement, and before the concrete is poured and formed into a whole, the hook connection and / or welding connection plays a role in bearing the deadweight of the suspension column reinforcement.

[0013] Furthermore, the intersection of the longitudinal reinforcement of the suspension column at the root of the suspension column and the external expansion reinforcement is tied or welded; before the concrete is poured and formed into a whole, it also plays a role in bearing the deadweight of the suspension column reinforcement.

[0014] Although the reinforced concrete column anchoring structure adopting the above structure solves the problems of hollowing and cracking at the root of the reinforced concrete column, the specific construction process still needs further explanation.

[0015] The second part of the present invention:

[0016] In order to facilitate construction workers to carry out anchoring construction work on reinforced concrete hanging columns, reduce pouring difficulties, ensure compaction through vibration, and avoid potential safety hazards, the present invention provides a reinforced concrete hanging column anchoring construction method, comprising the following construction steps:

[0017] (1) When pouring the floor slab, reserve pouring holes on the floor slab and anchor both ends of the expanded steel bars into the floor slab around the pouring holes;

[0018] (2) Install the column reinforcement cage or prefabricated column, extend the column longitudinal reinforcement at the root of the column reinforcement cage or prefabricated column upward into the floor slab casting hole, bend it and hook and / or weld it to the floor slab reinforcement; tie or weld the intersection of the column longitudinal reinforcement at the root of the column reinforcement cage or prefabricated column and the external expansion reinforcement;

[0019] (3) Formwork support is provided on the periphery of the steel cage of the suspension column to form a pouring cavity for the suspension column; or formwork support is provided on the periphery of the root of the prefabricated suspension column to form a pouring cavity at the root of the suspension column;

[0020] (4) Concrete is poured into the pouring cavity of the suspension column or the pouring cavity at the root of the suspension column and the pouring hole through the pouring hole. During the concrete pouring process, a vibrating rod is inserted into the pouring cavity of the suspension column or the pouring cavity at the root of the suspension column through the pouring hole to vibrate the concrete poured into the pouring cavity of the suspension column or the pouring cavity at the root of the suspension column and the pouring hole. After the concrete pouring is completed, the suspension column is anchored.

[0021] Furthermore, the two ends of the externally expanded steel bars in step (1) are hooked and / or welded to the floor slab steel bars around the casting hole, thereby improving the anchoring reliability of the externally expanded steel bars and avoiding displacement of the externally expanded steel bars during casting of the floor slab.

[0022] Furthermore, in step (1), when the pouring holes reserved on the floor slab encounter beams, pouring holes are reserved on the floor slab within the outer extension contour of the base of the hanging column and not covered by the beams.

[0023] Furthermore, in step (4), after the vibration is completed, if it is found that the concrete surface in the pouring hole drops during the self-compacting process of the concrete, the concrete refilling operation is performed.

[0024] The present invention is beneficial in that:

[0025] (1) By adopting the reinforced concrete column anchoring structure of the present invention, the cross-section of the column root is enlarged, which effectively improves the tensile, bending and shear bearing capacity of the column, thereby reducing the risk of cracking; when the column is suspended under the floor slab, the structure is also a local reinforcement measure of the floor slab, which can effectively increase the anchoring length of the longitudinal force-bearing steel bars of the column in the floor slab; the enlargement of the column root increases the pouring space, making it easier to pour, vibrate and compact the concrete, thereby effectively avoiding hollowing at the column root; on the basis of improving the structural strength of the column, it also provides a basis for facilitating construction.

[0026] (2) By adopting the reinforced concrete column anchoring construction method of the present invention, construction workers can stand at the reserved pouring holes on the floor slab at the root of the column, and pour and vibrate concrete from the top to the bottom through the pouring holes, so as to avoid the construction workers operating in the narrow space under the floor slab, thereby greatly simplifying the construction, making the construction operation simple and convenient, and making the construction quality easy to control; the pouring holes reserved in the floor slab above the root of the column are naturally blocked synchronously after the column concrete or the concrete at the root of the column is poured, so that the concrete is formed in one step without the need for secondary treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of adding hanging columns and hanging beams under the upper beams and floor slabs in the open space;

[0028] Figure 2 It is a schematic diagram of pouring the roots of hanging columns under the upper beams and floor slabs in the open space;

[0029] Figure 3 This is a schematic diagram showing hollowing and cracking at the base of the hanging column under the upper floor slab of an open space;

[0030] Figure 4 It is a schematic diagram of the anchoring structure of the reinforced concrete suspension column of the present invention;

[0031] Figure 5 This is a schematic diagram of the construction method of the present invention using prefabricated hanging columns for construction. Figure 1 ;

[0032] Figure 6 yes Figure 5 A top view of the structure at the pouring hole of the middle floor slab, in which the floor slab reinforcement, the external expansion reinforcement and the longitudinal reinforcement of the hanging column are hidden;

[0033] Figure 7 This is a schematic diagram of the construction method of the present invention using prefabricated hanging columns for construction. Figure 2 ;

[0034] Figure 8 yes Figure 7 A top view of the structure at the pouring hole of the middle floor slab, where the hanging column is located at a beam, and the floor slab reinforcement, external expansion reinforcement and hanging column longitudinal reinforcement are hidden in the figure;

[0035] Fig. 9 This is a top view of the structure at the pouring hole of the floor slab, where the hanging column is located at the intersection of two beams. The floor slab reinforcement, external expansion reinforcement and hanging column longitudinal reinforcement are hidden in the figure;

[0036] Fig.10 This is a schematic diagram of the construction method of the present invention using a hanging column steel cage for construction. Figure 1 ;

[0037] Fig.11 This is a schematic diagram of the construction method of the present invention using a hanging column steel cage for construction. Figure 2 ;

[0038] Fig.12 It is a schematic diagram of the connection between the longitudinal reinforcement of the suspension column of the present invention, the outwardly expanded reinforcement and the floor reinforcement; for ease of viewing, only two of the grid-like floor reinforcements are drawn in the figure, and the remaining floor reinforcements are not drawn.

[0039] Meaning of the reference numerals in the figures:

[0040] 1-casting hole, 2-floor slab, 20-beam, 21-floor slab reinforcement;

[0041] 3-hanging column, 31-prefabricated hanging column, 32-hanging column steel cage;

[0042] 4-external expansion steel bars, 5-concrete, 6-longitudinal steel bars of the suspension column;

[0043] 7-template, 8-pouring cavity at the root of the hanging column, 9-pouring cavity at the hanging column, 10-outward expansion contour line at the root of the hanging column. DETAILED DESCRIPTION

[0044] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0045] like Figure 4 As shown, a reinforced concrete column anchoring structure of this embodiment includes:

[0046] A pouring hole 1 is reserved and arranged on the floor slab 2;

[0047] A hanging column 3 is arranged below the pouring hole 1, and an external expansion steel bar 4 is arranged at the root of the hanging column 3 for expanding the root size of the hanging column 3, and both ends of the external expansion steel bar 4 are anchored in the floor slab 2 around the pouring hole 1;

[0048] Concrete 5 is poured at the root of the hanging column 3 and in the pouring hole 1.

[0049] like Fig.12 As shown, in this embodiment, the outward-expanding steel bars 4 are an inverted "J"-shaped structure. In this embodiment, eight outward-expanding steel bars 4 are provided, and the eight outward-expanding steel bars 4 are divided into two groups. The two groups of outward-expanding steel bars 4 are arranged perpendicularly to each other; they are used to improve the structural strength of the expanded part at the root of the hanging column 3; in actual application, the number of outward-expanding steel bars 4 can also be appropriately increased or decreased.

[0050] The longitudinal reinforcement 6 of the suspension column located at the root of the suspension column 3 extends upward to the casting hole 1 of the floor slab 2 and is bent and hooked and connected with the floor slab reinforcement 21 and welded; of course, the longitudinal reinforcement 6 of the suspension column located at the root of the suspension column 3 can also be only hooked and connected with the floor slab reinforcement 21 or only welded to the floor slab reinforcement 21 after extending upward to the casting hole 1 of the floor slab 2 and being bent; the longitudinal reinforcement 6 of the suspension column at the root of the suspension column 3 is effectively connected with the floor slab reinforcement 21, and before the concrete 5 is poured and formed into a whole, the hook connection and / or welding connection plays a role in bearing the deadweight of the reinforcement of the suspension column 3; in this embodiment, the floor slab reinforcement 21 specifically refers to the top reinforcement of the floor slab 2; the longitudinal reinforcement 6 of the suspension column at the root of the suspension column 3 is tied and connected with the intersection of the outward reinforcement 4, and of course, the longitudinal reinforcement 6 of the suspension column at the root of the suspension column 3 and the outward reinforcement 4 can also be welded; before the concrete is poured and formed into a whole, it also plays a role in bearing the deadweight of the reinforcement of the suspension column 3.

[0051] like Figure 5 , 6 As shown in FIG12 , one of the reinforced concrete column anchoring construction methods of this embodiment includes the following construction steps:

[0052] (1) When pouring the floor slab 2, a pouring hole 1 is reserved on the floor slab 2, and both ends of the externally expanded steel bars 4 are anchored into the floor slab 2 around the pouring hole 1; that is, when pouring the floor slab 2, the externally expanded steel bars 4 are also reserved in advance;

[0053] (2) Install the prefabricated suspension column 31, extend the suspension column longitudinal steel bar 6 at the root of the prefabricated suspension column 31 upward into the pouring hole 1 of the floor slab 2, bend it, hook and connect it with the floor slab steel bar 21, and weld it; tie and connect the suspension column longitudinal steel bar 6 at the root of the prefabricated suspension column 31 with the cross section of the external expansion steel bar 4;

[0054] (3) A template 7 is provided to support the periphery of the root of the prefabricated suspender 31 to form a pouring cavity 8 at the root of the suspender; at this time, the pouring hole 1 is connected to the pouring cavity 8 at the root of the suspender;

[0055] (4) Concrete 5 is poured into the pouring cavity 8 at the root of the column and the pouring hole 1 through the pouring hole 1. During the pouring of the concrete 5, a vibrating rod is inserted into the pouring cavity 8 at the root of the column through the pouring hole 1 to vibrate the concrete 5 poured into the pouring cavity 8 at the root of the column and the pouring hole 1. After the pouring of the concrete 5 is completed, the column 3 is anchored. Figure 4 .

[0056] When step (1) is implemented, the two ends of the externally-expanded steel bar 4 are hooked and connected to the floor slab steel bars 21 around the pouring hole 1 and welded; of course, the two ends of the externally-expanded steel bar 4 can also be connected to the floor slab steel bars 21 around the pouring hole 1 by only hooking or only welding; thereby improving the anchoring reliability of the externally-expanded steel bar 4 and avoiding displacement of the externally-expanded steel bar 4 when pouring the floor slab 2.

[0057] In step (4), after the vibration is completed, during the self-compacting process of the concrete 5, if it is found that the surface of the concrete 5 in the pouring hole 1 drops, the concrete 5 is refilled.

[0058] like Figure 7-9 As shown, when the reserved casting hole 1 on the floor slab 2 encounters the beam 20, a casting hole 1 is reserved on the floor slab 2 within the range of the outer expansion contour line 10 of the root of the hanging column and not covered by the beam 20; that is, when the upper part of the hanging column 3 is the beam 20, after the root of the hanging column 3 is expanded, it can extend upward along the side of the beam 20, and the casting hole 1 is still opened on the floor slab 2; in actual application, the hanging column longitudinal steel bar 6 at the root of the hanging column 3 can also be directly anchored into the beam 20, and hooked and connected with the beam reinforcement or hooked and connected with the floor slab reinforcement 21 passing here.

[0059] This construction method uses a prefabricated suspension column 31, which is prefabricated in the factory in advance. The root of the prefabricated suspension column 31 is reserved and exposed with the suspension column longitudinal steel bar 6, which is convenient for direct use on the construction site. The prefabricated suspension column 31 can reduce the amount of on-site construction.

[0060] like Figure 10-12As shown, another reinforced concrete column anchoring construction method of this embodiment includes the following construction steps:

[0061] (1) When pouring the floor slab 2, a pouring hole 1 is reserved on the floor slab 2, and both ends of the externally expanded steel bars 4 are anchored into the floor slab 2 around the pouring hole 1; that is, when pouring the floor slab 2, the externally expanded steel bars 4 are also reserved in advance;

[0062] (2) Install the column reinforcement cage 32, extend the column longitudinal reinforcement 6 at the root of the column reinforcement cage 32 upward to the pouring hole 1 of the floor slab 2, bend it, hook it with the floor slab reinforcement 21, and weld it together; weld the column longitudinal reinforcement 6 at the root of the column reinforcement cage 32 to the intersection of the expansion reinforcement 4;

[0063] (3) A formwork 7 is provided to support the periphery of the suspension column reinforcement cage 32 to form a suspension column pouring cavity 9; at this time, the pouring hole 1 is connected to the suspension column pouring cavity 9;

[0064] (4) Concrete 5 is poured into the column pouring cavity 9 and the pouring hole 1 through the pouring hole 1. During the pouring of the concrete 5, a vibrating rod is inserted into the column pouring cavity 9 through the pouring hole 1 to vibrate the concrete 5 poured into the column pouring cavity 9 and the pouring hole 1. After the pouring of the concrete 5 is completed, the column 3 is anchored. Figure 4 .

[0065] When step (1) is implemented, the two ends of the externally-expanded steel bar 4 are hooked and connected to the floor slab steel bars 21 around the pouring hole 1 and welded; of course, the two ends of the externally-expanded steel bar 4 can also be connected to the floor slab steel bars 21 around the pouring hole 1 by only hooking or only welding; thereby improving the anchoring reliability of the externally-expanded steel bar 4 and avoiding displacement of the externally-expanded steel bar 4 when pouring the floor slab 2.

[0066] In step (4), after the vibration is completed, during the self-compacting process of the concrete 5, if it is found that the surface of the concrete 5 in the pouring hole 1 drops, the concrete 5 is refilled.

[0067] like Fig.11 As shown, and refer to Figure 8 and 9 As shown, when the reserved casting hole 1 on the floor slab 2 encounters the beam 20, a casting hole 1 is reserved on the floor slab 2 within the range of the outer expansion contour line 10 of the root of the hanging column and not covered by the beam 20; that is, when the upper part of the hanging column 3 is the beam 20, after the root of the hanging column 3 is expanded, it can extend upward along the side of the beam 20, and the casting hole 1 is still opened on the floor slab 2; in actual application, the hanging column longitudinal steel bar 6 at the root of the hanging column 3 can also be directly anchored into the beam 20, and hooked and connected with the beam reinforcement or hooked and connected with the floor slab reinforcement 21 passing here.

[0068] This construction method adopts on-site cast reinforced concrete suspension column 3, the suspension column steel cage 32 is tied on-site, and then the suspension column longitudinal steel bars 6 at the root of the suspension column steel cage 32 are hooked and connected with the floor slab steel bars 21 in the casting hole 1 and welded, so as to realize the casting of reinforced concrete suspension column 3 and the anchoring of suspension column 3 directly on the construction site.

[0069] By adopting the above structure and construction method, the size of the root of the hanging column is enlarged, which not only increases the pouring operation surface, but also improves the tensile, bending and shear bearing capacity of the hanging column itself; by enlarging the root of the hanging column and opening a hole in the floor slab above the root of the hanging column to form a pouring hole, the hanging column concrete or the hanging column root concrete is poured through the pouring hole, which, on the one hand, avoids the construction difficulty caused by pouring under the slab, and on the other hand, ensures the quality of concrete pouring. The hanging column concrete, especially the pouring holes at the root of the hanging column and the openings on the floor slab can be formed at one time without the need for secondary sealing. At the same time, since the pouring holes on the floor slab are higher than the hanging column, a vertical effective pressure difference is formed after the concrete is vibrated, and effective compensation can be naturally formed during the self-compacting process of the concrete.

[0070] The present invention solves the problems of hollowing and cracking at the root of the reinforced concrete hanging column, and effectively improves the casting quality and the bearing capacity of the reinforced concrete hanging column. The construction operation is simple and convenient, there is no difficulty in casting and difficulty in compacting by vibration, no safety hazards are left, the construction cost is relatively low, and it is suitable for promotion and application.

[0071] In the description of the present invention, it is necessary to understand that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0072] In the description of the present invention, it should be noted that: unless otherwise clearly stipulated and limited, the terms "installation", "connection", "setting" and "formation" should be understood in a broad sense; for example: it can be a fixed connection, setting, or a detachable connection, setting, or an integrated structure; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be internal communication between two elements; for those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0073] In the description of the present invention, reference to terms such as "embodiment", "specific example" or "practical application" means that the specific features, structures, materials or characteristics described in combination with the embodiment are included in at least one embodiment or example of the present invention; the schematic expressions of the above terms do not necessarily refer to the same embodiment or example, and the specific features, structures, materials or characteristics described may be combined in an appropriate manner in any one or more embodiments or examples.

Claims

1. A reinforced concrete column anchoring construction method, characterized in that: The construction steps include: (1) When pouring the floor slab, reserve pouring holes on the floor slab and anchor both ends of the expanded steel bars into the floor slab around the pouring holes; (2) Install the column reinforcement cage or prefabricated column, extend the column longitudinal reinforcement at the root of the column reinforcement cage or prefabricated column upward into the floor slab casting hole, bend it and hook and / or weld it to the floor slab reinforcement; tie or weld the intersection of the column longitudinal reinforcement at the root of the column reinforcement cage or prefabricated column and the external expansion reinforcement; (3) Formwork support is provided on the periphery of the steel cage of the suspension column to form a pouring cavity for the suspension column; or formwork support is provided on the periphery of the root of the prefabricated suspension column to form a pouring cavity at the root of the suspension column; (4) Concrete is poured into the pouring cavity of the suspension column or the pouring cavity at the root of the suspension column and the pouring hole through the pouring hole. During the concrete pouring process, a vibrating rod is inserted into the pouring cavity of the suspension column or the pouring cavity at the root of the suspension column through the pouring hole to vibrate the concrete poured into the pouring cavity of the suspension column or the pouring cavity at the root of the suspension column and the pouring hole. After the concrete pouring is completed, the suspension column is anchored.

2. A reinforced concrete column anchoring construction method according to claim 1, characterized in that: The two ends of the outwardly expanded steel bars in step (1) are hooked and / or welded to the floor steel bars around the casting hole.

3. A reinforced concrete column anchoring construction method according to claim 1, characterized in that: In step (1), when the pouring holes reserved on the floor slab encounter beams, pouring holes are reserved on the floor slab within the outer extension contour of the base of the hanging column and not covered by the beams.

4. A reinforced concrete column anchoring construction method according to claim 1, characterized in that: In step (4), after the vibration is completed, if it is found that the concrete surface in the casting hole drops during the self-compacting process of the concrete, the concrete refilling operation is carried out.

5. A reinforced concrete column anchoring structure formed by the reinforced concrete column anchoring construction method according to claim 1, characterized in that: include: Pouring holes are reserved and set on the floor slab; A hanging column is arranged below the pouring hole, and an outward expansion steel bar for expanding the size of the root of the hanging column is arranged at the root of the hanging column, and both ends of the outward expansion steel bar are anchored in the floor slab around the pouring hole; the outward expansion steel bar is an inverted "J"-shaped structure; a plurality of outward expansion steel bars are arranged, and the plurality of outward expansion steel bars are divided into two groups, and the two groups of outward expansion steel bars are arranged perpendicularly and crosswise to each other; the longitudinal steel bars of the hanging column located at the root of the hanging column extend upward into the pouring hole of the floor slab and are bent and hooked and / or welded to the steel bars of the floor slab, and the intersection of the longitudinal steel bars of the hanging column at the root of the hanging column and the outward expansion steel bars is tied or welded; Concrete is poured at the base of the hanging column and in the pouring holes.

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