A core tube concealed column constructed using the reverse construction method and its construction method

Abstract

The core tube concealed column and its construction method of the reverse construction method belong to the field of core tube concealed column construction technology. In view of the special working conditions of the reverse construction method, the present invention optimizes the construction method of the stirrups of the core tube concealed column. The stirrups of the core tube concealed column are processed in segments. Specifically, each closed stirrup is processed into two segments and a welding length is reserved. The stirrup segments are tied to the outside of the vertical stirrups, and then the tied stirrup segments are welded to form a closed stirrup system. This ensures that the stirrups can still be tied smoothly after the construction of the upper structure, lower structure and vertical reinforcement is completed, reducing the construction difficulty and improving the construction efficiency.

Description

Technical Field

[0001] This invention belongs to the field of core tube concealed column construction technology, specifically a core tube concealed column constructed by reverse construction method and its construction method. Background Technology

[0002] Located at the center of the building structure, the core tube boasts high stiffness, significantly enhancing structural rigidity and improving stiffness distribution. Furthermore, the core tube effectively resists horizontal loads such as wind loads and seismic forces, strengthening the overall stability of the building. Secondly, the core tube's lighter weight allows for minimizing the cross-sectional dimensions of columns and walls, thereby reducing building materials and construction costs. Additionally, the core tube offers advantages such as high space utilization and convenient vertical transportation. For these reasons, core tube structures are widely used in super high-rise buildings, office buildings, airport terminals, and hospital buildings.

[0003] Concealed columns in the core tube are structural members located within the core tube and with the same width as the core tube wall, serving to ensure the overall strength and rigidity of the core tube. Typically, during the construction of concealed columns, after the vertical reinforcement bars are tied, pre-fabricated stirrups are placed over the vertical reinforcement bars from top to bottom. However, this method is only suitable for sequential construction. For the construction of stirrups in later-layered concealed columns where both the upper and lower horizontal structures and the vertical reinforcement bars of the core tube have already been completed, this method is clearly not feasible.

[0004] Chinese Patent Application No. 201811300594.2 discloses a reverse construction method for pre-reserving stirrups at column joints in a one-column-one-pile manner. During the construction of the column stirrups for one column and one pile, all the required stirrups for each layer of the structural column are stacked around the column. The pre-reserved stirrups for the current excavation layer are then tied and fixed to the beam-slab joint. Each time a layer is excavated downwards, the required stirrups for that layer are pre-reserved, and the remaining stirrups are lowered to the bottom of the structural column. In other words, the number of stirrups stacked on the structural column decreases as construction progresses downwards, and this process is repeated until all column stirrups are constructed. This pre-reserved stirrup method requires that the stirrups of the lower layers be placed at the bottom of the structural column before the construction of the current layer's stirrups. The stirrups are tied according to the designed spacing, allowing them to be directly in place without the need for on-site re-attaching.

[0005] However, if the core tube hidden columns already have piles when the superstructure is being constructed, and the number of stirrups in each core tube hidden column is large, and the thickness of the superstructure cannot meet the requirements for reserving all the stirrups for the construction floors and the floors to be constructed below, then stirrup reservation cannot be carried out. Summary of the Invention

[0006] The purpose of this invention is to provide a core tube concealed column and its construction method for reverse construction, so as to solve the technical problem that it is difficult to construct stirrups when the upper and lower horizontal structures have been completed and the vertical reinforcement of the core tube has been completed.

[0007] To address this, the present invention provides a core tube concealed column constructed using a reverse construction method. The core tube concealed column contains existing piles and existing vertical reinforcement bars arranged around the existing piles. The top and bottom of the core tube concealed column are respectively provided with an upper structure and a lower structure. The existing vertical reinforcement bars include central vertical reinforcement bars and lateral vertical reinforcement bars. The lateral vertical reinforcement bars are arranged on the side of the central vertical reinforcement bars near the core tube shear wall. The outer sides of the central vertical reinforcement bars and the lateral vertical reinforcement bars are segmented and equipped with main stirrups. The ends of each segment of the main stirrups are tied and welded together to form a ring structure.

[0008] Preferably, the central vertical reinforcement and the side vertical reinforcement are provided with first stirrups in sections near the core tube shear wall, and the ends of each section of the first stirrups are tied and welded to form a ring structure.

[0009] Preferably, multiple primary stirrups are provided between the central vertical reinforcement and the side vertical reinforcement on the side near the core tube shear wall.

[0010] Preferably, the outer side of the vertical reinforcement bar is provided with a second stirrup, and the ends of each segment of the second stirrup are tied and welded together to form a ring structure.

[0011] Preferably, diagonal tie bars are provided between the vertical bars on two adjacent sides of the central vertical bar.

[0012] Preferably, the ends of the diagonal tie rods are all bent inward toward the interior of the core tube concealed column and hooked onto the central vertical steel bar.

[0013] Preferably, a third stirrup is provided between the middle vertical reinforcement adjacent to the side vertical reinforcement and the side vertical reinforcement, and the ends of each segment of the third stirrup are tied and welded together to form a ring structure.

[0014] In addition, the present invention also provides a construction method for a core tube concealed column constructed using the reverse construction method as described above, comprising the following steps:

[0015] S1. Construct existing piles, raising the top elevation of the existing piles to the top elevation of the floor to be constructed, and complete the construction of the superstructure.

[0016] S2. Excavate downwards to the bottom of the floor to be constructed and complete the construction of the substructure;

[0017] S3. Continue excavating downwards to the bottom elevation of the foundation to complete the foundation construction;

[0018] S4. Bind existing vertical reinforcing bars;

[0019] S5. The main stirrups are installed in sections, and the ends of each section of the main stirrups are tied together to form a ring structure.

[0020] S6. Weld the ends of each segment of the main stirrup together;

[0021] S7. Tie the core tube reinforcement and pour the core tube concrete.

[0022] Preferably, between S6 and S7, a first stirrup is installed in sections between the central vertical reinforcement and the side vertical reinforcement on the side closer to the core tube shear wall. A second stirrup is installed in sections on the outside of the side vertical reinforcement. A third stirrup is installed between the central vertical reinforcement and the side vertical reinforcement adjacent to the side vertical reinforcement. The ends of each section of the first, second, and third stirrups are tied and welded together to form a ring structure.

[0023] Preferably, diagonal bracing is provided between the vertical reinforcing bars on the two adjacent sides of the central vertical reinforcing bar, and the ends of the diagonal bracing are bent toward the inside of the core tube hidden column and hooked to the central vertical reinforcing bar.

[0024] Compared with the prior art, the features and beneficial effects of the present invention are as follows:

[0025] (1) In view of the special working conditions of reverse construction, the present invention optimizes the construction method of stirrups of the core tube hidden column. The stirrups of the core tube hidden column are processed in segments. Specifically, the closed stirrups are processed into two segments and the welding length is reserved. The stirrup segments are tied to the outside of the vertical stirrups, and then the tied stirrup segments are welded to form a closed stirrup system. This ensures that the stirrups can be tied smoothly after the construction of the upper structure, lower structure and vertical reinforcement is completed, reducing the construction difficulty and improving the construction efficiency.

[0026] (2) The present invention can improve the overall stability of the concealed column by binding the main stirrup segments and welding the segments of the column stirrups together. In addition, the first stirrup, the second stirrup and the third stirrup are set to increase the restraint on the main stirrup, prevent the main stirrup from yielding too early, and also improve the shear resistance of the core tube concealed column section. The main stirrup and the first stirrup, the second stirrup and the third stirrup work together to achieve a better shear resistance effect.

[0027] (3) The present invention also includes diagonal bracing. Firstly, diagonal bracing can significantly improve the shear strength of the concealed column and also improve the bonding between the concrete and the reinforcing steel in the concealed column, enabling the concrete and the reinforcing steel to work together better, thereby improving the overall stiffness of the concealed column. Secondly, diagonal bracing can also reduce the workload of the main stirrups, the first stirrups, the second stirrups, and the third stirrups, reducing their stress under compression. Furthermore, diagonal bracing can also change the cracking direction of the concrete, causing the cracks to gradually extend towards the direction of the diagonal bracing, thereby slowing down the expansion of vertical cracks and improving the crack shape. Attached Figure Description

[0028] Figure 1 This is a plan view of the core tube;

[0029] Figure 2 This is a schematic elevation view of the hidden columns in the core tube.

[0030] Figure 3 This is a schematic diagram showing the arrangement of existing vertical reinforcing bars inside the hidden column of the core tube in Example 1;

[0031] Figure 4 This is a cross-sectional schematic diagram of the core tube hidden column in Example 1;

[0032] Figure 5 This is a schematic diagram of the cracking of each stirrup in Example 1;

[0033] Figure 6 for Figure 4 A schematic diagram of section 1-1;

[0034] Figure 7 for Figure 6 Enlarged diagram of part A in the middle;

[0035] Figure 8 This is a schematic diagram showing the arrangement of existing vertical reinforcing bars inside the hidden column of the core tube in Example 2;

[0036] Figure 9 This is a cross-sectional schematic diagram of the hidden column in the core tube in Example 2;

[0037] Figure 10 This is a schematic diagram showing the cracking of each stirrup in Example 2;

[0038] Figure 11 for Figure 9 Schematic diagram of section 2-2;

[0039] Figure 12 for Figure 11 Enlarged schematic diagram of part B in the middle.

[0040] Attached diagram labels: 1-Existing pile, 2-Superstructure, 3-Substructure, 4-Existing vertical reinforcement, 41-Middle vertical reinforcement, 42-Side vertical reinforcement, 5-Core tube shear wall, 6-Main stirrup, 7-First stirrup, 8-Second stirrup, 9-Diagonal tie bar, 10-Third stirrup. Detailed Implementation

[0041] To make the technical means, innovative features, objectives and effects of this invention easier to understand, the invention will be further described below.

[0042] The embodiments described herein are specific implementations of the present invention, used to illustrate the concept of the invention, and are illustrative and exemplary, and should not be construed as limiting the implementation or scope of the invention. In addition to the embodiments described herein, those skilled in the art can employ other obvious technical solutions based on the content disclosed in the claims and specification of this application. These technical solutions include those that make any obvious substitutions and modifications to the embodiments described herein.

[0043] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," "outer," "front end," "rear end," "both ends," "one end," and "the other end," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0044] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0045] The total construction area of ​​a certain project is 100,861.65 m². 2 The above-ground building area is 67,861.65 m². 2 Underground building area 33,000 m² 2The building has one basement level and seven to nine floors above ground, comprising 16 residential buildings and 5 ancillary buildings, totaling 750 units. The residential buildings are shear wall structures, while the ancillary buildings and basement are frame structures. The underground structure was constructed using a reverse construction method in some areas, and the core tube's concealed columns were constructed using a post-overlay method.

[0046] like Figure 1 The diagram shows a core tube with concealed columns positioned along its outer edge; these are referred to as concealed core tube columns in this invention. These concealed core tube columns can be edge columns, in which case they are arranged in a straight line with the core tube shear wall 5; alternatively, they can be corner columns, in which case they are arranged in an L-shape with the core tube shear wall 5. For example... Figure 2 As shown, the core tube concealed column is equipped with existing piles 1 and existing vertical steel bars 4 set around the existing piles 1. The top and bottom of the core tube concealed column are respectively equipped with upper structure 2 and lower structure 3. That is, before the stirrups are tied, the existing piles 1, upper structure 2 and lower structure 3 have all been constructed.

[0047] Example 1

[0048] The existing vertical reinforcing bars 4 have already been tied inside the concealed columns of the core tube, such as... Figure 3 As shown, the existing vertical reinforcement 4 includes central vertical reinforcement 41 and side vertical reinforcement 42. The side vertical reinforcement 42 is located on the side of the central vertical reinforcement 41 near the core tube shear wall 5. The central vertical reinforcement 41 is arranged in a rectangular shape, while the side vertical reinforcement 42 is arranged in a C-shape, and the width of the central vertical reinforcement 41 is equal to the width of the side vertical reinforcement 42. The spacing of the central vertical reinforcement 41 near the core tube shear wall 5 is the same as the spacing of the side vertical reinforcement 42, which facilitates the binding of stirrups.

[0049] like Figure 4 and Figure 5 As shown, the outer sides of the central vertical reinforcement 41 and the side vertical reinforcement 42 are segmented with main stirrups 6. The ends of each segment of the main stirrups 6 are tied and welded together to form a ring structure. Specifically, the main stirrups 6 are processed into two segments and then tied to the outside of the large rectangle formed by the central vertical reinforcement 41 and the side vertical reinforcement 42. The main stirrups 6 serve to restrain the central vertical reinforcement 41 and the side vertical reinforcement 42, which can improve the overall stability of the core tube concealed column. It should be noted that there is a lot of overlap between the stirrups in the horizontal direction. To more clearly illustrate the form of each stirrup, Figure 5 The position of the stirrups shown in the image is different from their actual position.

[0050] To increase the restraint of the main stirrups 6, prevent them from yielding prematurely, and improve the shear resistance of the core tube concealed column section, this invention provides segmented first stirrups 7 between the central vertical reinforcement 41 and the side vertical reinforcement 42 on the side near the core tube shear wall 5. The ends of each segment of the first stirrup 7 are tied and welded together to form a ring structure. Multiple sets of first stirrups 7 are provided between the central vertical reinforcement 41 and the side vertical reinforcement 42 on the side near the core tube shear wall 5. The number of first stirrups 7 can be determined based on the width of the core tube concealed column, the spacing between adjacent central vertical reinforcements 41, and the spacing between adjacent side vertical reinforcements 42. Specifically... Figure 4 For example, the number of the first set of stirrups 7 is two. One set of the first set of stirrups 7 is placed between every three rows of central vertical bars 41 and side vertical bars 42. One central vertical bar 41 and one side vertical bar 42 are reserved between adjacent sets of the first set of stirrups 7. Similarly, each set of the first set of stirrups 7 is made into two segments. The first set of stirrups 7 interacts with the main stirrups 6 to improve the shear resistance.

[0051] Secondly, this invention provides secondary stirrups 8 segmented around the outer side of the vertical side reinforcing bars 42. The ends of each segment of the secondary stirrups 8 are tied and welded together to form a ring structure. Similarly, each set of secondary stirrups 8 is made into two segments. For example... Figure 4 As shown, the second stirrup 8 is tied to the outside of the two rows of side vertical bars 42 near the middle vertical bar 41 to restrain the side vertical bars 42.

[0052] In addition, the present invention also includes a third stirrup 10 between the central vertical reinforcement 41 and the side vertical reinforcement 42 adjacent to the side vertical reinforcement 42. The ends of each segment of the third stirrup 10 are tied and welded together to form a ring structure. Similarly, the third stirrup 10 is made into two segments. The third stirrup 10 is tied to the outside of the central vertical reinforcement 41 and the side vertical reinforcement 42, which are set parallel to the core tube shear wall 5 and located outside the core tube concealed column, to constrain these central vertical reinforcement 41 and side vertical reinforcement 42. At the same time, the third stirrup 10 interacts with the main stirrup 6 and the second stirrup 8 to improve the shear resistance.

[0053] The invention also includes diagonal braces 9 between the vertical reinforcing bars on two adjacent sides of the central vertical reinforcing bar 41. The ends of the diagonal braces 9 are all bent inwards towards the interior of the core tube concealed column and hooked onto the central vertical reinforcing bar 41. For example... Figure 4As shown, in this invention, when tying the diagonal tie bars 9, a central vertical steel bar 41 is reserved at the corner position. The end of the diagonal tie bar 9 is tied between the central vertical steel bars 41 of two adjacent sides, and multiple diagonal tie bars 9 are tied between every two adjacent sides, with a central vertical steel bar 41 reserved between the multiple diagonal tie bars 9. The diagonal tie bars 9 interact with the main stirrups 6, the first stirrup 7, the second stirrup 8, and the third stirrup 10 to improve the shear resistance.

[0054] like Figure 6 and Figure 7 As shown, the main stirrup 6, the first stirrup 7, the second stirrup 8, the diagonal tie bar 9, and the third stirrup 10 of the present invention are all arranged horizontally. The main stirrup 6, the first stirrup 7, the second stirrup 8, the diagonal tie bar 9, and the third stirrup 10 form a stirrup system, which is arranged at intervals along the vertical direction of the core tube concealed column, with a spacing of 100mm between two adjacent stirrup systems.

[0055] The construction method for the core tube concealed columns constructed using the above reverse construction method includes the following steps:

[0056] S1. Construct existing pile 1, raising the top elevation of existing pile 1 to the top elevation of the floor to be constructed, and complete the construction of the superstructure 2.

[0057] S2. Excavate downwards to the bottom of the floor to be constructed and complete the construction of the substructure 3.

[0058] S3. Continue excavating downwards to the bottom elevation of the foundation to complete the foundation construction.

[0059] S4. Bind existing vertical reinforcing bars 4.

[0060] S5. The main stirrups 6 are installed in sections, and the ends of each section of the main stirrups 6 are tied together to form a ring structure.

[0061] S6. Weld the ends of each segment of the main stirrup 6 together. A first stirrup 7 is installed in sections between the central vertical reinforcement 41 and the side vertical reinforcement 42 on the side closest to the core tube shear wall 5. A second stirrup 8 is installed in sections outside the side vertical reinforcement 42. A third stirrup 10 is installed between the central vertical reinforcement 41 and the side vertical reinforcement 42 adjacent to the side vertical reinforcement 42. The ends of each segment of the first stirrup 7, second stirrup 8, and third stirrup 10 are tied and welded together to form a ring structure. Diagonal braces 9 are also installed between the vertical reinforcements on the two adjacent sides of the central vertical reinforcement 41. The ends of the diagonal braces 9 are bent inwards towards the interior of the core tube concealed column and hooked onto the central vertical reinforcement 41.

[0062] S7. Tie the core tube reinforcement and pour the core tube concrete.

[0063] Example 2

[0064] In this embodiment, the core tube concealed column is a corner column, meaning that both sides of the core tube concealed column are connected to the core tube shear wall 5, and the core tube shear wall 5 and the core tube concealed column are arranged in an L-shape. Specifically, Figure 8 and Figure 9 For example, the core tube shear wall 5 is connected to both the north and east sides of the hidden column of the core tube.

[0065] like Figure 8 As shown, in this embodiment, the existing vertical steel bar 4 also includes a central vertical steel bar 41 and a side vertical steel bar 42. Unlike the first embodiment, in this embodiment, the two adjacent sides of the central vertical steel bar 41 are provided with side vertical steel bars 42. Specifically, the north and east sides of the central vertical steel bar 41 are provided with side vertical steel bars 42.

[0066] like Figure 9 and Figure 10 As shown, in this embodiment, two sets of main stirrups 6 are provided. One set of main stirrups 6 is placed outside the central vertical steel bar 41 and the side vertical steel bar 42 located on the north side of the central vertical steel bar 41. The other set of main stirrups 6 is placed outside the central vertical steel bar 41 and the side vertical steel bar 42 located on the east side of the central vertical steel bar 41.

[0067] In this embodiment, two sets of primary stirrups 7 are provided. One set of primary stirrups 7 is placed between the central vertical reinforcement 41 on the side near the core tube shear wall 5 and the side vertical reinforcement 42 located on the north side of the central vertical reinforcement 41. The other set of primary stirrups 7 is placed between the central vertical reinforcement 41 on the side near the core tube shear wall 5 and the side vertical reinforcement 42 located on the east side of the central vertical reinforcement 41.

[0068] In this embodiment, two sets of secondary stirrups 8 are provided. One set of secondary stirrups 8 is placed on the outside of the side vertical reinforcement 42 located on the north side of the central vertical reinforcement 41, and the other set of secondary stirrups 8 is placed on the outside of the side vertical reinforcement 42 located on the east side of the central vertical reinforcement 41.

[0069] In this embodiment, two sets of third stirrups 10 are provided. One set of third stirrups 10 is placed between the middle vertical bar 41 adjacent to the side vertical bar 42 and the side vertical bar 42 located on the north side of the middle vertical bar 41. The other set of third stirrups 10 is placed between the middle vertical bar 41 adjacent to the side vertical bar 42 and the side vertical bar 42 located on the east side of the middle vertical bar 41.

[0070] like Figure 11 and Figure 12As shown, in this embodiment, the main stirrup 6, the first stirrup 7, the second stirrup 8, the diagonal tie bar 9, and the third stirrup 10 are all arranged horizontally. The main stirrup 6, the first stirrup 7, the second stirrup 8, the diagonal tie bar 9, and the third stirrup 10 form a stirrup system, which is arranged at intervals along the vertical direction of the core tube concealed column, with a spacing of 100mm between two adjacent stirrup systems.

[0071] The construction method for the core tube concealed column constructed using the above reverse construction method is basically the same as that in Example 1, including the following steps:

[0072] S1. Construct existing pile 1, raising the top elevation of existing pile 1 to the top elevation of the floor to be constructed, and complete the construction of the superstructure 2.

[0073] S2. Excavate downwards to the bottom of the floor to be constructed and complete the construction of the substructure 3.

[0074] S3. Continue excavating downwards to the bottom elevation of the foundation to complete the foundation construction.

[0075] S4. Bind existing vertical reinforcing bars 4.

[0076] S5. The main stirrups 6 are installed in sections, and the ends of each section of the main stirrups 6 are tied together to form a ring structure.

[0077] S6. Weld the ends of each segment of the main stirrup 6 together. A first stirrup 7 is installed in sections between the central vertical reinforcement 41 and the side vertical reinforcement 42 on the side closest to the core tube shear wall 5. A second stirrup 8 is installed in sections outside the side vertical reinforcement 42. A third stirrup 10 is installed between the central vertical reinforcement 41 and the side vertical reinforcement 42 adjacent to the side vertical reinforcement 42. The ends of each segment of the first stirrup 7, second stirrup 8, and third stirrup 10 are tied and welded together to form a ring structure. Diagonal braces 9 are also installed between the vertical reinforcements on the two adjacent sides of the central vertical reinforcement 41. The ends of the diagonal braces 9 are bent inwards towards the interior of the core tube concealed column and hooked onto the central vertical reinforcement 41.

[0078] S7. Tie the core tube reinforcement and pour the core tube concrete.

[0079] The above embodiments are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A core tube hidden column for reverse construction, used in the working condition that both upper and lower structures have been completed, vertical steel bars of the core tube have been completed, and stirrups are difficult to construct, wherein the core tube hidden column is internally provided with an existing pile (1) and an existing vertical steel bar (4) arranged at the periphery of the existing pile (1), and the top and bottom of the core tube hidden column are respectively provided with an upper structure (2) and a lower structure (3), characterized in that, The existing vertical steel bars (4) include middle vertical steel bars (41) and side vertical steel bars (42), the side vertical steel bars (42) are arranged on one side of the middle vertical steel bars (41) close to the core tube shear wall (5), and the outer sides of the middle vertical steel bars (41) and the side vertical steel bars (42) are provided with main stirrups (6), the ends of each segment of the main stirrups (6) are tied and welded into a ring structure; The first stirrups (7) are arranged between the middle vertical steel bars (41) close to the core tube shear wall (5) and the side vertical steel bars (42) on the outer sides of the middle vertical steel bars (41) and the side vertical steel bars (42); The second stirrups (8) are arranged on the outer sides of the side vertical steel bars (42), and the ends of each segment of the second stirrups (8) are tied and welded into a ring structure; The third stirrups (10) are arranged between the middle vertical steel bars (41) adjacent to the side vertical steel bars (42) and the side vertical steel bars (42), and the ends of each segment of the third stirrups (10) are tied and welded into a ring structure.

2. The core wall hidden column of the top-down construction method according to claim 1, wherein A plurality of first stirrups (7) are arranged between the middle vertical steel bars (41) close to the core tube shear wall (5) and the side vertical steel bars (42).

3. The core wall hidden column of the top-down construction method according to claim 1, characterized in that, The diagonal bars (9) are arranged between the vertical steel bars of two adjacent sides of the middle vertical steel bars (41).

4. The core wall hidden column of the top-down construction method according to claim 3, characterized in that, The ends of the diagonal bars (9) are all bent towards the inside of the core tube concealed column and hooked on the middle vertical steel bars (41).

5. A construction method of a core tube hidden column of a top-down construction method according to any one of claims 1 to 4, characterized in that, The method comprises the following steps: S1, constructing an existing pile (1), the pile top of the existing pile (1) is at the top elevation of a to-be-constructed floor, and the construction of an upper structure (2) is completed; S2, excavating downwards to the bottom of the to-be-constructed floor, and completing the construction of a lower structure (3); S3, continuing to excavate downwards to the bottom elevation of a foundation, and completing the construction of the foundation; S4, tying the existing vertical steel bars (4); S5, arranging the main stirrups (6) in sections, and tying the ends of each segment of the main stirrups (6) into a ring structure; S6, welding the ends of each segment of the main stirrups (6); S7, tying the core tube steel bars, and pouring core tube concrete.

6. The construction method of a core wall hidden column of top-down construction according to claim 5, wherein Between S6 and S7, the first stirrups (7) are arranged in sections between the middle vertical steel bars (41) close to the core tube shear wall (5) and the side vertical steel bars (42), the second stirrups (8) are arranged in sections on the outer sides of the side vertical steel bars (42), the third stirrups (10) are arranged in sections between the middle vertical steel bars (41) adjacent to the side vertical steel bars (42) and the side vertical steel bars (42), and the ends of each segment of the first stirrups (7), the second stirrups (8) and the third stirrups (10) are tied and welded into a ring structure.

7. The construction method of a core wall hidden column of a top-down method construction according to claim 5, characterized by, The diagonal bars (9) are arranged between the vertical steel bars of two adjacent sides of the middle vertical steel bars (41), and the ends of the diagonal bars (9) are all bent towards the inside of the core tube concealed column and hooked on the middle vertical steel bars (41).

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