A precast concrete ground beam-frame column connection joint and its construction method

Abstract

The present invention discloses a precast concrete ground beam-frame column connection node and its construction method, which includes a transfer column, a ground beam, and a frame column connected in sequence from bottom to top; a top steel plate and a core column are arranged on the top surface of the transfer column, the inside of the core column is hollow, and the height of the core column is equal to the height of the ground beam; an end steel plate and a top steel plate are respectively arranged on the end face and the top surface of the ground beam, and the end steel plate and the side surface of the core column are connected by bolts; angle limbs and a bottom steel plate are arranged on the bottom surface of the frame column; the angle limbs extend from the bottom surface of the frame column to the top steel plate of the transfer column, a bottom end steel plate is arranged at the bottom of the angle limbs, and the bottom end steel plate and the top steel plate are connected by bolts. The angle limbs are located at the included angle formed between several ground beams, the side surface of the angle limbs is in contact with the ground beam, and the extending length of the angle limbs is the same as the height of the ground beam; the bottom steel plate is arranged avoiding the angle limbs, the sum of the vertical projection areas of the angle limbs and the bottom steel plate is the same as the cross-sectional area of the frame column, and the bottom steel plate and the top steel plate of the ground beam are connected by bolts.

Description

Technical Field

[0001] The invention belongs to the fields of civil engineering and precast assembled structures, and relates to a connection node between a precast concrete ground beam and a frame column and a construction method thereof. Background Art

[0002] The connection node and construction method of precast components are key issues in assembled structures. In particular, the connection node between a precast concrete ground beam and a frame column has a great influence on green and low-carbon assembly construction and the overall mechanical properties of the structure.

[0003] Existing precast concrete ground beams and frame columns mostly adopt reserved steel bars. After connection with grouting sleeves, secondary casting of concrete is carried out to complete on-site assembly connection. The internal force is transmitted through grouting sleeves or threaded sleeves, and the post-cast concrete and precast components work together through a rough interface. Sleeve connection has defects such as missed grouting, insufficient grouting, and insufficient insertion depth of steel bars in the project, and there is no fast and efficient detection method, so it is difficult to ensure the force transmission of steel bars. Moreover, at the node, the steel bars of the two-way ground beam and the vertical frame column intersect, and the number of joints is numerous, the operating space for sleeves is narrow, and it is extremely difficult to align the steel bars during on-site assembly, resulting in low construction efficiency. The contact surface between the post-cast concrete and the precast component is prone to cracking, and the tensile and shear resistance capabilities are insufficient, unable to exert the characteristics of fast and efficient assembly. Summary of the Invention

[0004] The purpose of the invention is to overcome the above-mentioned disadvantages of the prior art, and provide a connection node between a precast concrete ground beam and a frame column and a construction method thereof, without wet operation and welding work on site, with high assembly efficiency, reliable force transmission performance, and improved connection strength and reliability of the node.

[0005] To achieve the above purpose, the invention adopts the following technical solutions:

[0006] A connection node between a precast concrete ground beam and a frame column includes a transfer column, a ground beam, and a frame column connected in sequence from bottom to top;

[0007] A top plate and a core column are arranged on the top surface of the transfer column. The core column is hollow inside, and the height of the core column is equal to the height of the ground beam. An end plate and a top plate are respectively arranged on the end face and the top surface of the ground beam. The end plate and the side surface of the core column are connected by bolts;

[0008] Angle limbs and a bottom plate are arranged on the bottom surface of the frame column; the angle limbs extend from the bottom surface of the frame column to the top plate of the transfer column. A bottom end plate is arranged at the bottom of the angle limbs. The bottom end plate and the top plate are connected by bolts. The angle limbs are located at the included angle formed between several ground beams. The side surface of the angle limbs contacts the ground beam, and the extending length of the angle limbs is the same as the height of the ground beam. The bottom plate is arranged avoiding the angle limbs. The sum of the vertical projection areas of the angle limbs and the bottom plate is the same as the cross-sectional area of the frame column. The bottom plate and the top plate of the ground beam are connected by bolts.

[0009] Preferably, the number of ground beams is two to four. From a top-down perspective, after the ground beams are connected to the core columns, they form a straight shape, an L shape, a T shape, or a cross shape.

[0010] Preferably, the core column is a rectangular steel pipe.

[0011] Preferably, the bottom end of the core column is located inside the transfer column and is integrally connected to the transfer column.

[0012] Preferably, bolt installation grooves are provided at the bolt installation positions of the ground beams and the frame columns.

[0013] Preferably, shear keys are provided on the bottom surface of the frame column. The shear keys protrude from the bottom surface of the frame column. The outer contour dimensions of the shear keys are the same as the inner contour dimensions of the core column, and the shear keys extend into the core column; a rectangular hole is provided at the center of the bottom steel plate, and the dimensions of the rectangular hole are the same as the outer contour dimensions of the shear keys.

[0014] Preferably, longitudinal steel bars are provided inside the ground beams. The longitudinal steel bars are connected to the end steel plates, and the anchor bars of the top steel plate extend to the longitudinal steel bars at the bottom of the ground beams and are connected.

[0015] Preferably, high-strength bolts are used for the bolts.

[0016] A construction method for a precast concrete ground beam-frame column connection node according to any one of the above, comprising the following processes:

[0017] Fix the transfer column to the set position, place the ground beam on the transfer column, then align the end of the ground beam with the core column, and use bolts to connect the top steel plate to the core column;

[0018] Place the frame column on the top of the ground beam. The corner limbs pass through the included angle formed between the ground beams and contact the top of the transfer column. The sides of the corner limbs contact the ground beams, and the bottom steel plate and the top steel plate are connected by bolts; the bottom surface of the frame column contacts the top surface of the ground beam, and the bottom steel plate and the top steel plate of the ground beam are connected by bolts.

[0019] Preferably, when the frame column is placed on the top of the ground beam, the shear key of the frame column extends into the core column.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] In the present invention, the ground beam, transfer column, and frame column are connected into a whole through steel plate combined bolts. The core column and the steel plate combined bolts can reliably transfer the tensile force of the steel bars and the internal force of the cross-section in the concrete member. The frame column transfers the axial force, shear force, and bending moment of the column through the steel plate combined bolts at the bottom steel plate and the corner limbs. The force transfer mechanism is clear, the force transfer path is simple, and the joint performance is reliable. After the installation of the corner limbs of the frame column, not only can the bending moment and tensile force at the bottom of the column be efficiently transferred, but also the ground beam can be limited and protected, avoiding detachment and collapse due to excessive displacement under large earthquakes. When the bolts are tightened, they are equivalent to applying prestress, which helps to improve the early stiffness of the joint and avoid premature cracking. On-site connection is completed only by tightening the bolts, reducing technical requirements, labor costs, and the operation is clean. After the joint is completed, it is simple and regular. There is no welding operation and no wet operation on-site, and no longer relying on the secondary concrete setting to achieve the anchoring effect, greatly improving the assembly efficiency and connection quality.

[0022] Furthermore, the core column at the upper part of the transfer column is designed to be rectangular, which can avoid the bolt collision problem of the cross-shaped ground beam, and the bolt assembly can be completed without changing the cross-sectional size and reinforcement of the ground beam, meeting the requirements of standardized production.

[0023] Furthermore, the shear key at the bottom of the frame column can effectively resist the horizontal shear force at the bottom of the frame column, avoid the combined tension and shear force of the bolts, ensure that the bolts are mainly in tension, and give full play to the material performance advantages. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a schematic structural diagram of the connection joint of the present invention;

[0025] Figure 2 is a cross-sectional view of the connection joint structure of the present invention;

[0026] Figure 3 is a perspective view of the connection joint of the present invention from above.

[0027] Wherein: 1-transfer column; 11-top steel plate; 12-bottom steel plate; 13-core column; 2-ground beam; 21-top steel plate; 22-end steel plate; 23-first bolt installation groove; 3-frame column; 31-shear key; 32-corner limb; 33-bottom end steel plate; 34-bottom steel plate; 35-longitudinal reinforcement in the corner limb; 36-longitudinal reinforcement in the frame column; 37-second bolt installation groove; 4-bolt. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] The present invention will be further described in detail below with reference to the accompanying drawings:

[0029] As Figure 1 shown, it is a precast concrete ground beam-frame column connection joint of the present invention, including a transfer column 1, a ground beam 2, and a frame column 3 connected in sequence from bottom to top.

[0030] The number of ground beams 2 is two to four. Taking the top-down view as the standard, after the ground beam 2 is connected to the core column 13, it is in the shape of a straight line, an L shape, a T shape or a cross shape. In this embodiment, the cross shape is taken as an example.

[0031] Top surface steel plates 11 and bottom surface steel plates 12 with bolt screw holes are embedded at the bottom and top of the concrete transfer column 1. The longitudinal reinforcement bars in the transfer column 1 are welded to the end-embedded top surface steel plates 11 and bottom surface steel plates 12. A core column 13 made of high-strength steel is provided at the upper part of the transfer column 1. The core column 13 is made of rectangular steel pipes, and bolt screw holes are opened on all four side wall plates. The height of the core column is the same as the cross-sectional height of the connected ground beam 2. The bottom end of the core column 14 is located inside the transfer column 1 and is integrally connected to the transfer column 1; the height of the concrete part of the transfer column 1 is not less than its cross-sectional height. The transfer column 1 can be a short column on the foundation or a short column on the rubber bearing, and the concrete is poured and cured in the factory to the age.

[0032] The ground beam 2 can be a steel section composite member or an ordinary frame beam. End plates 22 and top plates 21 with bolt screw holes are embedded at the ends and the upper surface of the ground beam 2. The longitudinal reinforcement bars of the ground beam are welded to the end-embedded end plates 22, and the anchor bars of the top plates 21 embedded on the upper surface extend to the bottom longitudinal reinforcement bars of the ground beam 2 and are reliably connected to ensure the anchorage strength; rectangular first bolt installation grooves 23 are reserved at all bolt 4 connection points, and the concrete is poured and cured in the factory to the age.

[0033] The frame column 3 can be a concrete column or a steel reinforced concrete composite column. As Figure 2 shown, a shear key 31 made of rectangular steel pipe is embedded at the bottom of the frame column 3, and its outer contour dimensions are the same as the inner contour dimensions of the core column 13. The shear key 31 extends out of the bottom surface of the frame column 3 and the shear key 31 extends into the core column 13; angle limbs 32 are provided at the bottom of the frame column 3. In this embodiment, taking the cross shape as an example, the number of angle limbs 32 is four. The angle limbs 32 extend out of the bottom surface of the frame column 3 to the top surface steel plate 11 of the transfer column 1. The outstretched length of the angle limbs 32 from the bottom of the frame column 3 is the same as the cross-sectional height of the ground beam 2. The angle limbs 32 are located at the included angles formed between the ground beams 2. The side edges of the angle limbs 32 are fitted with the included angles between the ground beams 2, and two sides of the angle limbs 32 are in contact with the ground beam 2; a bottom end plate 33 with bolt round holes is embedded at the bottom of the angle limb 32, and the longitudinal reinforcement bars 35 of the angle limb are welded to the bottom end plate 33; as Figure 3 shown, a cross-shaped bottom plate 34 is embedded at the bottom of the frame column 3. The longitudinal reinforcement bars 36 in the frame column are welded to the cross-shaped bottom plate 34. A central rectangular hole is provided in the bottom plate 34 for the shear key 31 to pass through. The bottom plate 34 is arranged avoiding the angle limbs 32. The sum of the vertical projection areas of the shear key 31, the bottom plate 34 and the four angle limbs 32 is the same as the cross-sectional area of the frame column 3; rectangular second bolt installation grooves 37 are reserved at all bolt 4 connection points, and the concrete is poured and cured to the age.

[0034] The transfer column 1, the ground beam 2 and the frame column 3 are arranged in sequence from bottom to top. The core column 14 is arranged vertically upward. The end steel plate 22 and the side surface of the core column 13 are connected by bolts 4 to connect the transfer column 1 and the ground beam 2. The bottom steel plate 33 at the bottom of the corner limb 32 and the top steel plate 11 are connected by bolts 4. The bottom steel plate 34 at the bottom surface of the frame column 3 and the top steel plate 21 of the ground beam 2 are connected by bolts 4. The bolts 4 are high-strength bolts.

[0035] The construction process of the precast concrete ground beam-frame column connection joint is as follows:

[0036] Lift the transfer column 1 into place and align it geometrically with the axis network;

[0037] Lift the ground beam 2 into place. The lower surface of the ground beam 2 is seated on the top steel plate 11 embedded on the upper surface of the transfer column 1. Then align the four wall plates of the core column 13 of the ground beam 2 with the transfer column 1 respectively, adjust the hole positions of the end steel plates 22, align the two-way axes, and insert the high-strength bolts 4 for temporary fixation;

[0038] Lift the frame column 3 directly above the transfer column 1 and slowly lower it. The shear key 31 of the frame column 3 extends into the core column 13. The four corner limbs 32 are attached to the inside corners of the cross ground beam 2 and descend to the top steel plate 11 embedded in the upper part of the transfer column 1. The cross-shaped bottom steel plate 34 embedded at the bottom of the frame column 3 is exactly seated on the top steel plate 21 embedded on the upper surface of the cross ground beam 2, and insert the high-strength bolts 4 for temporary fixation.

[0039] Check the three-dimensional dimensions of the structure. After confirming that there is no error, tighten all the high-strength bolts 4 in sequence, and then fill the first bolt installation groove 23 and the second bolt installation groove 37 with high-strength grouting material to complete the joint connection.

[0040] The above content is only to illustrate the technical idea of the present invention, and the protection scope of the present invention cannot be limited thereby. Any modification made on the basis of the technical solution according to the technical idea proposed by the present invention falls within the protection scope of the claims of the present invention.

Claims

1. A precast concrete ground beam-frame column connection joint, characterized in that, It includes a transfer column (1), a ground beam (2), and a frame column (3) connected successively from bottom to top; On the top surface of the transfer column (1), there are a top surface steel plate (11) and a core column (13). The core column (13) is hollow inside, and the height of the core column (13) is equal to the height of the ground beam (2). On the end face and the top surface of the ground beam (2), there are an end steel plate (22) and a top steel plate (21) respectively. The end steel plate (22) and the side surface of the core column (13) are connected by bolts (4); On the bottom surface of the frame column (3), there are corner limbs (32) and a bottom steel plate (34). The corner limbs (32) extend out of the bottom surface of the frame column (3) to the top surface steel plate (11) of the transfer column (1). At the bottom of the corner limbs (32), there is a bottom end steel plate (33). The bottom end steel plate (33) and the top surface steel plate (11) are connected by bolts (4). The corner limbs (32) are located at the included angles formed between several ground beams (2). The side surfaces of the corner limbs (32) are in contact with the ground beams (2). The extending length of the corner limbs (32) is the same as the height of the ground beam (2). The bottom steel plate (34) is arranged avoiding the corner limbs (32). The sum of the vertical projection areas of the corner limbs (32) and the bottom steel plate (34) is the same as the cross-sectional area of the frame column (3). The bottom steel plate (34) and the top steel plate (21) of the ground beam (2) are connected by bolts (4); On the bottom surface of the frame column (3), there is a shear key (31). The shear key (31) extends out of the bottom surface of the frame column (3). The outer contour dimensions of the shear key (31) are the same as the inner contour dimensions of the core column (13). The shear key (31) extends into the core column (13); A rectangular hole is arranged at the center of the bottom steel plate (34), and the dimensions of the rectangular hole are the same as the outer contour dimensions of the shear key (31); Longitudinal steel bars are arranged inside the ground beam (2). The longitudinal steel bars are connected with the end steel plate (22). The anchor bars of the top steel plate (21) extend to the longitudinal steel bars at the bottom of the ground beam (2) and are connected.

2. The precast concrete ground beam-frame column connection joint according to claim 1, characterized in that The number of the ground beams (2) is two to four. From a top-down perspective, after the ground beams (2) are connected to the core column (13), they are in a straight shape, an L shape, a T shape, or a cross shape.

3. The precast concrete ground beam-frame column connection joint according to claim 1, characterized in that The core column (13) is a rectangular steel pipe.

4. The precast concrete ground beam-frame column connection joint according to claim 1, characterized in that, The bottom end of the core column (13) is located inside the transfer column (1) and is integrally connected with the transfer column (1).

5. The precast concrete ground beam-frame column connection joint according to claim 1, characterized in that Both the ground beam (2) and the frame column (3) are provided with bolt installation grooves at the positions of the bolts (4).

6. The precast concrete ground beam-frame column connection joint according to claim 1, characterized in that, The bolts (4) are high-strength bolts.

7. A construction method for a precast concrete ground beam-frame column connection joint according to any one of claims 1-6, characterized in that, It includes the following processes: The transfer column (1) is fixed to the set position. The ground beam (2) is placed on the transfer column (1). Then, the end of the ground beam (2) is aligned with the core column (13), and the top steel plate (21) and the core column (13) are connected by bolts (4); The frame column (3) is placed on the top of the ground beam (2). The corner limbs (32) pass through the included angles formed between the ground beams (2) and contact the top of the transfer column (1). The side surfaces of the corner limbs (32) are in contact with the ground beams (2). The bottom end steel plate (33) and the top surface steel plate (11) are connected by bolts (4). The bottom surface of the frame column (3) is in contact with the top surface of the ground beam (2). The bottom steel plate (34) and the top steel plate (21) of the ground beam (2) are connected by bolts (4).

8. The construction method of the precast concrete ground beam-frame column connection joint according to claim 7, characterized in that, When the frame column (3) is placed on the top of the ground beam (2), the shear key (31) of the frame column (3) extends into the core column (13).

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