Prefabricated column efficient assembly structure and construction method thereof

Abstract

According to the efficient prefabricated column assembling structure and the construction method thereof, the prefabricated columns are connected with the lower-layer prefabricated columns through the longitudinal steel bars at the bottom ends, the load-bearing steel pipes in the middles of the bottom ends of the prefabricated columns bear longitudinal loads of the prefabricated columns, and the positioning tool positions and aligns the longitudinal steel bars of the upper prefabricated columns and the lower prefabricated columns; the inclined strut system comprises a first inclined strut unit and a second inclined strut unit which are correspondingly and detachably connected to two orthogonal vertical faces of the prefabricated column correspondingly, and the first inclined strut unit and the second inclined strut unit jointly restrain side-tipping displacement of the prefabricated column. During construction, the prefabricated columns and all the embedded parts are prefabricated firstly, the positioning tool and the embedded base of the inclined strut are preassembled on site, a floor slab is poured, after the prefabricated columns are lifted to be in butt joint, the inclined strut system is installed after the load-bearing steel pipe bears pressure, and after perpendicularity is checked, hooks are loosened, and upper and lower longitudinal steel bars are connected. The problems that in traditional construction, a tower crane occupies a long time, and procedure connection is not smooth are solved, and the assembly type building construction efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of prefabricated building construction technology, and in particular to a high-efficiency prefabricated column assembly structure and its construction method. Background Technology

[0002] In the field of prefabricated buildings, the precast column-cast-in-place beam structure system is widely used due to its advantages of combining industrialized production with the flexibility of on-site construction. The rebar connection of precast columns often adopts the extrusion sleeve connection method, which uses mechanical force to tightly interlock the sleeve and the rebar, providing reliable force transmission performance. However, there are significant efficiency bottlenecks in the current precast column assembly and construction process, with the core issue concentrated on the occupation of tower crane resources.

[0003] In traditional precast column assembly construction, after the precast column is hoisted into place, it relies on the longitudinal reinforcing bars to bear the vertical load. Therefore, the tower crane hook can only be released after all the longitudinal reinforcing bars have been connected with extrusion sleeves. This construction process results in the tower crane being occupied by a single precast column for an extended period, preventing it from being used for the vertical transportation of other components or materials in a timely manner. Especially in large-scale projects with a large number of precast columns and heavy assembly tasks, the efficiency of the tower crane, as a key vertical transportation device, directly affects the overall construction progress. The bottleneck caused by the traditional process of tower crane occupation can easily lead to poor coordination of construction procedures, thereby causing delays in the construction period.

[0004] Meanwhile, the existing temporary support system for precast columns mainly only provides lateral stability and cannot independently bear the vertical self-weight load of the precast columns. Therefore, it is impossible to detach the tower crane before the rebar connection is completed. In addition, during the assembly of precast columns, the positioning and alignment accuracy of the upper and lower layers of rebar directly affects the efficiency of the connection operation. If the positioning deviation is large, additional time is required for adjustment, further extending the time the tower crane occupies the position. Summary of the Invention

[0005] The main objective of this invention is to provide a high-efficiency assembly structure for precast columns and its construction method, which solves the problems of long tower crane usage time, poor process connection, and low construction efficiency in the traditional construction process of extrusion sleeve connection precast column assembly.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a high-efficiency assembly structure for precast columns, wherein longitudinal steel bars are provided inside the precast column along the height direction, and the lower end of the longitudinal steel bars extends out of the bottom end of the precast column by a certain distance for connection with the corresponding longitudinal steel bars of the lower precast column; The load-bearing steel pipe is embedded in the middle of the bottom end of the precast column, and its bottom end abuts against the lower floor slab to bear the longitudinal load after the precast column is assembled and placed. The positioning fixture is fixedly connected to the beam reinforcement of the floor slab and is used to position and align the longitudinal reinforcement of the upper and lower precast columns. The bracing system includes a first bracing unit and a second bracing unit that are detachably connected to two orthogonal vertical surfaces of the precast column, and both are detachably connected to the lower floor slab. The first bracing unit and the second bracing unit are arranged orthogonally to constrain the lateral displacement of the precast column. The lifting nails are pre-embedded at the top of the precast column for hoisting the precast column.

[0007] In the preferred embodiment, the axis of the load-bearing steel pipe is collinear with the central axis of the precast column; The load-bearing steel pipe and the precast column concrete are poured simultaneously to form an integrated structure; The extension length of the lower end of the load-bearing steel pipe is adapted to the cast-in-place height of the adjacent precast column assembly structure.

[0008] In the preferred embodiment, the positioning fixture includes a positioning plate and a positioning sleeve; The positioning plate is equipped with several positioning sleeves, and the number and position of the positioning sleeves correspond one-to-one with the longitudinal steel bars of the lower precast column. The inner diameter of the positioning sleeve is larger than the diameter of the longitudinal reinforcing bar; The positioning plate is welded and fixed to the beam reinforcement, and the positioning plate is kept horizontal.

[0009] In the preferred embodiment, each vertical surface of the precast column is provided with at least two longitudinally spaced anchor points, and the first diagonal bracing unit and the second diagonal bracing unit each include two diagonal bracing components. The top of the bracing components of each bracing unit is detachably connected to an anchor point on a precast column, and the bottom is detachably connected to the same embedded base of the lower floor slab.

[0010] In the preferred embodiment, a pre-embedded sleeve is pre-embedded in the side wall of the precast column, and the diagonal bracing assembly includes an adjustable diagonal brace rod, the upper end of which is detachably connected to the pre-embedded sleeve by bolts. The embedded base is an Ω-shaped steel bar, which is embedded and fixed in the concrete of the lower floor slab. Its structural plane is perpendicular to the vertical plane of the corresponding precast column. The lower end of the adjustable diagonal brace can be detachably connected to the top arc section of the Ω-shaped steel bar in the pre-embedded base.

[0011] In the preferred embodiment, a guide bearing seat is also provided at the top of the lower precast column corresponding to the load-bearing steel pipe; The guide bearing seat includes a guide sleeve, a folding part, and a bearing plate that are coaxially and sequentially fixedly connected; The lower end of the load-bearing steel pipe is coaxially sleeved inside the guide sleeve; The folded part can be compressed and deformed along the axial direction to adapt to the assembly stroke of the precast column; The guide bearing seat is welded and fixed to the beam reinforcement, and the guide bearing seat is kept horizontal.

[0012] In the preferred embodiment, the folding part is a multi-section coaxial nested sleeve structure, and each sleeve section is circumferentially spaced with axial cuts to form several independent folding petals; In two adjacent sleeve sections, the outer wall of the inner sleeve and the inner wall of the outer sleeve are respectively provided with matching guide cone surfaces to guide the coaxial nesting of adjacent sleeves.

[0013] In the preferred embodiment, when the folded part in the guide bearing seat is in its uncompressed initial state, the guide sleeve at its top is higher than the top of the longitudinal steel bar of the lower precast column.

[0014] A construction method for a high-efficiency precast column assembly structure, the method comprising: S1. Prefabrication is carried out in the factory, including binding the structural steel bars of the prefabricated columns, including longitudinal steel bars, and embedding pre-embedded sleeves, hanging nails and load-bearing steel pipes at preset points. The interior of the load-bearing steel pipes is poured synchronously with the prefabricated columns. S2. Pre-install the guide bearing seat and positioning fixture at the corresponding position at the top of the lower precast column, and weld and fix them to the beam reinforcement. Determine the installation position of the diagonal brace, weld and fix the embedded base to the beam reinforcement, and pour the concrete of the lower floor slab so that each embedded part and the lower floor slab form an integral structure. S3. Lift the precast column and connect it with the lower precast column through the positioning tool. After the load-bearing steel pipe abuts against the lower floor slab and bears its own weight load, install the diagonal bracing system. S4. After the diagonal bracing system is installed, the tower crane is released, and the longitudinal steel bars of the upper and lower precast columns are connected by compression sleeves one by one.

[0015] In the preferred embodiment, in step S3, when the self-weight of the precast column is transferred to the load-bearing steel pipe, the tower crane stops the lowering operation and begins to install the diagonal bracing system. The diagonal bracing units of the diagonal bracing system are not tightened yet. The verticality of one of the supporting facades of the precast column is observed with a theodolite and adjusted to within the allowable deviation of the specification. Then the diagonal bracing unit of that facade is tightened. The verticality of the other supporting facade of the precast column is observed and adjusted again before the diagonal bracing unit of the other facade is fixed. After the diagonal bracing system is fixed, the tower crane begins to unload the load without immediately releasing the hook. The position and verticality of the precast column are then re-measured. Only after continuous observation for a certain period of time without any changes can the tower crane release the hook and begin hoisting the next precast column.

[0016] This invention provides a highly efficient precast column assembly structure and its construction method. By pre-embedding load-bearing steel pipes at the bottom of the precast column, it can directly bear the longitudinal load of the precast column after assembly, without relying on the connection of the upper and lower longitudinal steel bars. This breaks the limitation of traditional construction where the hook cannot be released until all steel bar connection work is completed. It allows the tower crane to be released in time after the diagonal bracing system is installed, and then used for the vertical transportation of other precast column components or materials. This significantly shortens the time that a single precast column is occupied by the tower crane, alleviates the pressure of tower crane resource shortage in large projects, and ensures the smooth connection of construction procedures.

[0017] The positioning fixture is fixedly connected to the beam reinforcement, which can accurately guide the alignment of the longitudinal reinforcement of the upper and lower precast columns, reducing the time spent on on-site reinforcement adjustment and avoiding long waiting times for tower crane adjustments due to positioning deviations, thus further improving assembly efficiency. The diagonal bracing system adopts an orthogonally arranged double diagonal bracing unit structure, which can effectively restrain the lateral displacement of the precast columns and ensure that the precast columns remain stable after the tower crane is unhooked. This provides safe and reliable construction conditions for subsequent reinforcement connection operations, eliminating the need for continuous tower crane support for stability and supporting the early release of the tower crane from a structural design perspective.

[0018] The guide bearing seat not only disperses the concentrated stress of the load-bearing steel pipe on the lower floor slab, preventing structural damage, but its guiding function also assists in the rapid and accurate connection of precast columns, reducing repeated adjustments during hoisting and indirectly shortening the tower crane's hoisting time. The overall structure adopts a combination of factory prefabrication and efficient on-site assembly. The components are reliably connected and easy to assemble and disassemble, and the construction process is simple and orderly. It works synergistically from multiple dimensions such as load bearing, positioning guidance, and stability assurance, minimizing the unnecessary occupation of the tower crane. While improving the construction efficiency of prefabricated buildings, it ensures the structural stability and connection reliability of the precast column assembly, combining economy and practicality. Attached Figure Description

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments: Figure 1 This is the overall assembly structure diagram of Embodiment 1 of the present invention; Figure 2 This is a structural diagram of the positioning tooling of the present invention; Figure 3 This is a cross-sectional view of the internal reinforcement of the precast column of the present invention; Figure 4 This is a schematic diagram of the hanging nail arrangement structure of the present invention; Figure 5 This is a connection structure diagram of any diagonal brace component of the present invention; Figure 6 This is the overall assembly structure diagram of Embodiment 2 of the present invention; Figure 7 This is a structural diagram of the guide bearing seat of the present invention when it is not compressed; Figure 8 This is a diagram of the compression structure connecting the guide bearing seat and the load-bearing steel pipe of the present invention.

[0020] In the diagram: 1. Precast column; 101. Longitudinal reinforcement; 102. Embedded sleeve; 2. Load-bearing steel pipe; 3. Positioning fixture; 301. Positioning plate; 302. Beam reinforcement; 4. Diagonal bracing system; 5. First diagonal bracing unit; 501. Second diagonal bracing unit; 502. Embedded base; 503. Adjustable diagonal bracing rod; 504. Hanging nail; 6. Guide bearing seat; 7. Guide sleeve; 701. Folding part; 702. Axial cut; 7021. Folding petal; 7022. Bearing plate; 703. Detailed Implementation

[0021] Example 1 like Figure 1-5 As shown, a high-efficiency assembly structure for precast columns is provided. The precast column 1 has longitudinal steel bars 101 arranged inside along the height direction. The lower end of the longitudinal steel bars 101 extends a certain distance from the bottom end of the precast column 1 and is used to connect with the corresponding longitudinal steel bars 101 of the lower precast column 1. The load-bearing steel pipe 2 is embedded in the middle of the bottom end of the precast column 1, and its bottom end abuts against the lower floor slab to bear the longitudinal load after the precast column 1 is assembled in place. The positioning fixture 3 is fixedly connected to the beam reinforcement 4 of the floor slab and is used to position and align the longitudinal reinforcement 101 of the upper and lower precast columns 1. The diagonal bracing system 5 includes a first diagonal bracing unit 501 and a second diagonal bracing unit 502, which are respectively detachably connected to two orthogonal vertical surfaces of the precast column 1. Both are detachably connected to the lower floor slab. The first diagonal bracing unit 501 and the second diagonal bracing unit 502 are arranged orthogonally to constrain the lateral displacement of the precast column 1. The lifting nail 6 is pre-embedded at the top of the precast column 1 for hoisting the precast column 1.

[0022] This application improves the structure of the precast column 1 connected by the extrusion sleeve, solving the problem of precast components occupying the hook for extended periods. The device first relies on the load-bearing steel pipe 2 embedded in the column base as an independent pressure-bearing component, temporarily bearing the vertical load during the hoisting phase. This allows the tower crane to detach the hook after installing the diagonal bracing system 5, freeing up tower crane resources. The diagonal bracing system 5 adopts an adjustable support structure with spatial orthogonal arrangement, eliminating docking deviations. The overall structure is simple and effective, reducing the occupation of hoisting equipment while systematically improving the reliability of the connected assembly structure.

[0023] The lifting points for precast column 1 utilize pre-embedded special lifting nails 6, used in conjunction with specialized lifting equipment. Compared to pre-embedded lifting rings, lifting nails 6 offer advantages such as rapid lifting, safety, and reliability, while also providing a more uniform stress distribution on the component, reducing the risk of cracking. The selection of lifting nails 6 employs an envelope design method, using the maximum load borne by the nail 6 under various working conditions as the design value. In this application, two lifting nails 6 are used for each column, with a design load of 5t for each nail 6, meeting the lifting requirements for the heaviest precast column 1.

[0024] In the preferred embodiment, the axis of the load-bearing steel pipe 2 is collinear with the central axis of the precast column 1; The load-bearing steel pipe 2 and the precast column 1 are poured with concrete simultaneously to form an integrated structure; The lower extension length of the load-bearing steel pipe 2 is adapted to the cast-in-place height of the adjacent precast column 1 assembly structure.

[0025] The precast column 1 has a rectangular cross-section, with dimensions including 600mm×600mm, 600mm×700mm, and 700mm×700mm. In this embodiment, C30 concrete is used, so the weight of each precast column 1 is between 2.160t and 5.460t.

[0026] The longitudinal reinforcing bars 101 of the precast column 1 are connected using extrusion sleeves, with a pre-reserved casting height of approximately 500mm at the bottom as operating space for sleeve extrusion. Therefore, in this embodiment, a steel pipe with dimensions of Φ80×5 is selected, and the steel pipe is filled with concrete of the same material as the precast column 1 to bear the vertical load of the entire precast column 1. The load-bearing steel pipe 2 is embedded in the length direction of the bottom end of the precast column 1, and the transverse structural reinforcing bars of the precast column 1 are densely planted. In this embodiment, it is preferred that the length of the load-bearing steel pipe 2 embedded in the precast column 1 is 1 / 10 of the height of the precast column 1, and the length of the load-bearing steel pipe 2 extending beyond the bottom end face is greater than 500mm.

[0027] Without considering the lateral restraint of the steel pipe on the concrete, and only considering the bearing capacity of the concrete itself, the load-bearing capacity of the load-bearing steel pipe 2 of this size is calculated as follows: F = 40mm × 40mm × π × 30MPa = 150.8KN ≈ 15t > 5.460t, and its safety factor can reach 2.7, that is, the vertical support can support the self-weight load of the precast column 1.

[0028] In the preferred embodiment, the positioning fixture 3 includes a positioning plate 301 and a positioning sleeve 302; The positioning plate 301 is provided with a number of positioning sleeves 302, and the number and position of the positioning sleeves 302 correspond one-to-one with the longitudinal steel bars 101 of the lower precast column 1. The inner diameter of the positioning sleeve 302 is larger than the diameter of the longitudinal reinforcing bar 101; The positioning plate 301 is welded and fixed to the beam reinforcement 4, and the positioning plate 301 is kept horizontal.

[0029] The positioning sleeve 302 of the positioning fixture 3 needs to allow the smooth insertion of the longitudinal reinforcing bar 101 while limiting the radial displacement of the longitudinal reinforcing bar 101. The positioning fixture 3 is placed on the upper layer of the beam reinforcement 4 and welded to the beam reinforcement 4 to prevent the longitudinal reinforcing bar 101 from shifting or moving during the concrete pouring process.

[0030] In the preferred embodiment, each vertical surface of the precast column 1 is provided with at least two longitudinally spaced anchor points, and the first diagonal bracing unit 501 and the second diagonal bracing unit 502 each include two diagonal bracing components. The top of the bracing components of each bracing unit is detachably connected to an anchor point on a precast column 1, and the bottom is detachably connected to the same embedded base 503 of the lower floor slab.

[0031] In the preferred embodiment, a pre-embedded sleeve 102 is pre-embedded in the side wall of the precast column 1, and the diagonal bracing assembly includes an adjustable diagonal bracing rod 504. The upper end of the adjustable diagonal bracing rod 504 is detachably connected to the pre-embedded sleeve 102 by bolts. The embedded base 503 is an Ω-shaped steel bar, which is embedded and fixed in the concrete of the lower floor slab and closely attached to the top surface of the precast floor slab. Its Ω-shaped structural plane is perpendicular to the vertical plane of the corresponding precast column 1. The lower end of the adjustable diagonal brace 504 can be detachably connected to the top arc-shaped section of the Ω-shaped steel bar in the pre-embedded base 503.

[0032] This diagonal bracing system 5 adopts a core design combining orthogonal arrangement and a single anchor point at the bottom, offering the dual advantages of structural stability and construction economy. The first diagonal bracing unit 501 and the second diagonal bracing unit 502, orthogonally arranged in space, form a stabilizing couple through bidirectional constraints, achieving spatial rigid body fixation with minimal support points. The two orthogonally arranged diagonal bracing units correspond to the orthogonal vertical surfaces of the precast column 1, comprehensively constraining the column's lateral tilt and horizontal displacement, forming a spatial force balance system, and avoiding the mechanical weaknesses of unidirectional support. The single anchor point design at the bottom ensures that the two diagonal braces on the same surface are jointly anchored to the same pre-embedded base 503, resulting in a clear and concentrated force path. This effectively offsets the horizontal and vertical components of the diagonal bracing, reducing the risk of stress concentration and improving overall overturning stiffness. Simultaneously, this structure significantly simplifies the construction process, requiring only one set of pre-embedded bases 503 to meet support needs, reducing material consumption and installation costs. Furthermore, the detachable connection design adapts to the high-efficiency requirements of precast column 1 assembly construction, achieving an organic unity of stability, practicality, and economy.

[0033] Example 2 Further explanation in conjunction with Example 1, such as Figure 2-8 The structure shown has a guide bearing seat 7 at the top of the lower precast column 1 corresponding to the load-bearing steel pipe 2; The guide bearing seat 7 includes a guide sleeve 701, a folding part 702 and a bearing plate 703 that are coaxially and sequentially fixedly connected; The lower end of the load-bearing steel pipe 2 is coaxially sleeved inside the guide sleeve 701; The folding part 702 can be compressed and deformed along the axial direction to adapt to the assembly stroke of the precast column 1; The guide bearing seat 7 is welded and fixed to the beam reinforcement 4, and the guide bearing seat 7 is kept horizontal.

[0034] In the preferred embodiment, the folding part 702 is a multi-section coaxial nested sleeve structure, and each sleeve section is provided with axial cuts 7021 spaced apart in the circumferential direction to form a number of independent folding petals 7022. In two adjacent sleeve sections, the outer wall of the inner sleeve and the inner wall of the outer sleeve are respectively provided with matching guide cone surfaces to guide the coaxial nesting of adjacent sleeves.

[0035] In the preferred embodiment, when the folded part 702 in the guide bearing seat 7 is in the uncompressed initial state, the guide sleeve 701 at its top end is higher than the top end of the longitudinal steel bar 101 of the lower precast column 1.

[0036] Since the load-bearing steel pipe 2 serves as a support for the overall self-weight load of the precast column 1, the pressure at its contact point with the lower floor slab is relatively high, resulting in stress concentration. Based on Example 1, this embodiment introduces a bearing seat structure at this location. The surface area of ​​this steel structure disperses the stress generated by the smaller support at the bottom of the load-bearing steel pipe 2 onto the plane of the bearing plate 703, and then transfers it to the lower floor slab, reducing the risk of localized cracking.

[0037] During assembly, the guide bearing seat 7 is fixed at the design point on the beam reinforcement 4. Its top extends out of the upper end of the longitudinal reinforcement 101. When the precast column 1 is lowered, the weighing steel pipe 2 is placed in it for initial positioning and to guide its precise connection. When the precast column 1 is gradually pressed down, the folding petals 7022 of the multi-layer folded part 702 fold and shrink radially along the axial cut 7021, and expand in all directions at the same time, and finally form a complete ring bearing structure with the bearing plate 703 at the bottom.

[0038] This structure utilizes a folding-expansion mechanism to distribute the localized concentrated load of the column base steel pipe to the annular surface of the base slab, effectively preventing cracking of the lower floor slab due to concentrated pressure. Simultaneously, the shrinkage characteristics of the nested structure absorb minor deviations during hoisting, ensuring the positioning accuracy of the precast column 1. The entire structure is welded from ordinary steel, featuring a simple and low-cost process, and is integrally cast with the floor slab concrete, eliminating the need for later dismantling.

[0039] Example 3 Further explanation is provided in conjunction with Examples 1 and 2, such as... Figure 1-8 The structure shown illustrates a construction method for a high-efficiency precast column assembly structure, the method comprising: S1. Prefabrication is carried out in the factory, the structural steel bars of the prefabricated column 1, including the longitudinal steel bars 101, are tied, and the pre-embedded sleeves 102, hanging nails 6 and load-bearing steel pipes 2 are embedded at the preset points. The interior of the load-bearing steel pipes 2 is poured synchronously with the prefabricated column 1. S2. Pre-install the guide bearing seat 7 and the positioning tool 3 at the corresponding position at the top of the lower precast column 1, and weld them to the beam reinforcement 4 to determine the installation position of the diagonal brace. Weld the embedded base 503 to the beam reinforcement 4 and pour the concrete of the lower floor slab so that each embedded part and the lower floor slab form an integral structure. S3. Lift the precast column 1 and connect it with the lower precast column 1 through the positioning fixture 3. After the load-bearing steel pipe 2 abuts against the lower floor slab and bears its own weight load, install the diagonal bracing system 5. After the S4 and diagonal bracing system 5 is installed, the tower crane is released, and the longitudinal steel bars 101 of the upper and lower precast columns 1 are connected by compression sleeves.

[0040] In the preferred embodiment, in step S3, when the self-weight of the precast column 1 is transferred to the load-bearing steel pipe 2, the tower crane stops the lowering operation and begins to install the diagonal bracing system 5. The diagonal bracing units of the diagonal bracing system 5 are not tightened yet. The verticality of one of the supporting facades of the precast column 1 is observed with a theodolite and adjusted to within the allowable deviation of the specification. Then the diagonal bracing unit of that facade is tightened. After observing and adjusting the verticality of the other supporting facade of the precast column 1 again, the diagonal bracing unit of the other facade is fixed. After the diagonal bracing system 5 is fixed, the tower crane begins to unload the load without immediately releasing the hook. The position and verticality of the precast column 1 are then re-measured. Only after continuous observation for a certain period of time without any change can the tower crane release the hook and begin hoisting the next precast column 1.

[0041] This application uses a tower crane to hoist the precast columns 1. Before construction, the hoisting range line is drawn according to the tower crane lifting capacity table to determine whether different models of tower cranes can lift all the precast columns 1 within the coverage area. Considering a safety margin of 1.1, this embodiment preferably uses the TC7020-12 model tower crane to ensure that all precast columns 1 can be hoisted by the tower crane, thereby improving the installation efficiency of the precast columns 1.

[0042] Precise positioning of the reinforcing bars is a crucial step in the installation of precast columns 1. At the bottom of each precast column 1, specialized positioning fixtures 3 must be used to ensure the accurate position of the reinforcing bars. After installation, these positioning fixtures 3 must be welded to the beam reinforcement 4 to achieve stability and prevent the reinforcing bars from shifting or moving during concrete pouring.

[0043] After the concrete pouring is completed and the floor concrete has reached its strength, clean the bonding surface. According to the positioning axis, mark the positioning edge line and 200mm control line of the precast column 1 on the completed floor slab, and mark the 200mm control line. Then, pop up a 1000mm horizontal control line on the precast column to facilitate construction operations and control the level and height of the precast column 1.

[0044] Specifically, precast column 1 uses a squeeze sleeve connection method for rebar connection. The squeeze sleeve connection is a rebar connection method that uses mechanical force to plastically deform the steel sleeve and tightly interlock it with the ribbed rebar. Compared to conventional grouting sleeve connections, the squeeze sleeve connection eliminates the need for grouting material and curing time, resulting in higher construction efficiency.

[0045] Before the formal construction, the project determined the number of indentation layers to be 6 through type testing. The preset pressure for 20mm diameter steel bars was 45MPa-50MPa, and the preset pressure for 25mm diameter steel bars was 55MPa-60MPa.

[0046] Before sleeve extrusion, the reinforcing bars must be inspected and corrected. Sleeve extrusion should begin in the middle of the sleeve and proceed towards both ends sequentially. The spacing between each indentation should be uniform, with approximately 2cm left unextruded at the center connection point of the reinforcing bar. The outermost indentation should be close to the edge of the sleeve to create a constriction effect. The extrusion sequence on the same precast column section 1 should be symmetrical, with priority given to extruding the sleeves at the four corners.

[0047] After extrusion, the diameter of the indentation, the length of the extruded sleeve, and cracks are randomly inspected. The outer diameter of the sleeve at the indentation should be 0.80-0.90 times the original outer diameter of the sleeve, and the length of the sleeve after extrusion should be 1.10-1.15 times the original length of the sleeve. There should be no visible cracks in the extruded sleeve.

[0048] The above embodiments are merely preferred technical solutions of the present invention and should not be considered as limitations on the present invention. The scope of protection of the present invention should be limited to the technical solutions described in the claims, including equivalent substitutions of the technical features described in the claims. That is, equivalent substitutions and improvements within this scope are also within the scope of protection of the present invention.

Claims

1. A high-efficiency assembly structure for precast columns, characterized in that: The precast column (1) is provided with longitudinal steel bars (101) along the height direction inside. The lower end of the longitudinal steel bars (101) extends a certain distance from the bottom end of the precast column (1) and is used to connect with the corresponding longitudinal steel bars (101) of the lower precast column (1). The load-bearing steel pipe (2) is embedded in the middle of the bottom end of the precast column (1), and its bottom end abuts against the lower floor slab to bear the longitudinal load after the precast column (1) is assembled in place. The positioning fixture (3) is fixedly connected to the beam reinforcement (4) of the floor slab and is used to position and align the longitudinal reinforcement (101) of the upper and lower precast columns (1). The diagonal bracing system (5) includes a first diagonal bracing unit (501) and a second diagonal bracing unit (502) that are respectively detachably connected to two orthogonal vertical surfaces of the precast column (1), and both are detachably connected to the lower floor slab. The first diagonal bracing unit (501) and the second diagonal bracing unit (502) are arranged orthogonally to jointly constrain the lateral displacement of the precast column (1). The lifting nail (6) is pre-embedded at the top of the precast column (1) for hoisting the precast column (1).

2. The precast column high-efficiency assembly structure according to claim 1, characterized in that: The axis of the load-bearing steel pipe (2) is collinear with the central axis of the precast column (1); The load-bearing steel pipe (2) and the precast column (1) are poured with concrete simultaneously to form an integrated structure; The lower extension length of the load-bearing steel pipe (2) is adapted to the cast-in-place height of the adjacent precast column (1) assembly structure.

3. The high-efficiency assembly structure for precast columns according to claim 1, characterized in that: The positioning fixture (3) includes a positioning plate (301) and a positioning sleeve (302); The positioning plate (301) is provided with several positioning sleeves (302), and the number and position of the positioning sleeves (302) correspond one-to-one with the longitudinal steel bars (101) of the lower precast column (1); The inner diameter of the positioning sleeve (302) is larger than the diameter of the longitudinal reinforcing bar (101); The positioning plate (301) is welded and fixed to the beam reinforcement (4), and the positioning plate (301) is kept horizontal.

4. The high-efficiency assembly structure for precast columns according to claim 1, characterized in that: Each vertical surface of the precast column (1) is provided with at least two longitudinally spaced anchor points, and the first diagonal bracing unit (501) and the second diagonal bracing unit (502) each include two diagonal bracing components; The top of the bracing component of each bracing unit is detachably connected to an anchor point on a precast column (1), and the bottom is detachably connected to the same embedded base (503) of the lower floor slab.

5. The high-efficiency assembly structure for precast columns according to claim 4, characterized in that: An embedded sleeve (102) is pre-embedded in the side wall of the precast column (1). The diagonal bracing assembly includes an adjustable diagonal brace (504). The upper end of the adjustable diagonal brace (504) is detachably connected to the embedded sleeve (102) by bolts. The embedded base (503) is an Ω-shaped steel bar, which is embedded and fixed in the concrete of the lower floor slab. Its structural plane is perpendicular to the vertical plane of the corresponding precast column (1). The lower end of the adjustable diagonal brace (504) can be detachably connected to the top arc section of the Ω-shaped steel bar of the pre-embedded base (503).

6. The high-efficiency assembly structure for precast columns according to claim 1, characterized in that: A guide bearing seat (7) is also provided at the top of the lower precast column (1) corresponding to the load-bearing steel pipe (2); The guide bearing seat (7) includes a guide sleeve (701), a folding part (702) and a bearing plate (703) that are coaxially and fixedly connected in sequence. The lower end of the load-bearing steel pipe (2) is coaxially sleeved inside the guide sleeve (701); The fold (702) can be compressed and deformed along the axial direction to adapt to the assembly stroke of the precast column (1); The guide bearing seat (7) is welded and fixed to the beam reinforcement (4), and the guide bearing seat (7) is kept horizontal.

7. The high-efficiency assembly structure for precast columns according to claim 6, characterized in that: The folding part (702) is a multi-section coaxial nested sleeve structure, with each sleeve section having axial cuts (7021) spaced apart circumferentially to form several independent folding petals (7022). In two adjacent sleeve sections, the outer wall of the inner sleeve and the inner wall of the outer sleeve are respectively provided with matching guide cone surfaces to guide the coaxial nesting of adjacent sleeves.

8. The high-efficiency assembly structure for precast columns according to claim 6, characterized in that: When the folded part (702) in the guide bearing seat (7) is in the uncompressed initial state, the guide sleeve (701) at its top is higher than the top of the longitudinal steel bar (101) of the lower precast column (1).

9. A construction method for a high-efficiency precast column assembly structure according to any one of claims 1-8, characterized in that: The method includes: S1. Prefabrication is carried out in the factory. The prefabricated column (1) is tied with structural steel bars including longitudinal steel bars (101), and pre-embedded sleeves (102), hanging nails (6) and load-bearing steel pipes (2) are embedded at the preset points. The interior of the load-bearing steel pipes (2) is poured synchronously with the prefabricated column (1). S2, pre-install the guide bearing seat (7) and positioning fixture (3) at the corresponding position at the top of the lower precast column (1), and weld them to the beam reinforcement (4) to determine the installation position of the diagonal brace, weld the embedded base (503) to the beam reinforcement (4) to fix it, and pour the concrete of the lower floor slab so that each embedded part and the lower floor slab form an integral structure. S3. Lift the precast column (1) and connect it with the lower precast column (1) through the positioning fixture (3). After the load-bearing steel pipe (2) abuts against the lower floor slab and bears its own weight load, install the diagonal bracing system (5). S4. After the diagonal bracing system (5) is installed, the tower crane is released and the longitudinal steel bars (101) of the upper and lower precast columns (1) are connected by compression sleeves one by one.

10. The construction method for a high-efficiency precast column assembly structure according to claim 9, characterized in that: In step S3, when the self-weight of the precast column (1) is transferred to the load-bearing steel pipe (2), the tower crane stops the lowering operation and begins to install the diagonal bracing system (5). The diagonal bracing units of the diagonal bracing system (5) are not tightened temporarily. The verticality of one of the supporting facades of the precast column (1) is observed with a theodolite and adjusted to within the allowable deviation of the specification. Then the diagonal bracing unit of that facade is tightened. The verticality of the other supporting facade of the precast column (1) is observed and adjusted again before the diagonal bracing unit of the other facade is fixed. After the diagonal bracing system (5) is fixed, the tower crane begins to unload the load and does not release the hook for the time being. The position and verticality of the precast column (1) are re-measured. After continuous observation for a certain period of time without any change, the tower crane can release the hook and carry out the hoisting of the next precast column (1).

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