A concrete-steel column-to-foundation connection joint

Abstract

This utility model discloses a connection node between a concrete steel column and a foundation, comprising a concrete steel column and a foundation. The column base is vertically fixed with studs around its perimeter, and a connecting base plate is welded to its bottom. Anchor bolts are pre-embedded in the foundation, with their upper ends connected to the connecting base plate. A first outer cast-in-place layer is provided around the column base, containing a reinforcing steel skeleton. The reinforcing steel skeleton includes several vertical and horizontal reinforcing bars. The lower ends of the vertical reinforcing bars are pre-embedded in the foundation, and the vertical reinforcing bars are rectangularly distributed, including corner reinforcing bars at the four corners of the rectangle and intermediate reinforcing bars between the corner reinforcing bars. The horizontal reinforcing bars include first and second horizontal reinforcing bars spaced apart. The first horizontal reinforcing bars surround all the vertical reinforcing bars, and the second horizontal reinforcing bars surround all the intermediate reinforcing bars. A second outer cast-in-place layer is provided above the first outer cast-in-place layer and between it and the concrete steel column. This utility model has advantages such as high seismic performance and long service life.

Description

Technical Field

[0001] This utility model relates to the field of steel structure buildings, and in particular to a connection node between a concrete steel column and a foundation. Background Technology

[0002] Steel structure buildings are a type of highly integrated prefabricated building. Typically, individual modules are manufactured in a factory, the foundations are pre-cast and embedded on-site, and the connection between the steel columns and the foundations is installed on-site. The column base is a crucial node connecting the column and the foundation, and also a weak point in the structure. The rationality of this node directly affects the overall stability and reliability of the building structure. Existing steel column-foundation connection technologies often suffer from stress concentration, concrete cracking, and even delamination, necessitating further improvements. Utility Model Content

[0003] The purpose of this invention is to provide a connection node between a concrete steel column and a foundation to solve the problems existing in the prior art.

[0004] The purpose of this utility model is achieved as follows: A connection node between a concrete steel column and a foundation includes a concrete steel column and a foundation. The column base is vertically fixed with studs around its perimeter, and a connecting base plate is welded and fixed to its bottom. Anchor bolts are pre-embedded in the foundation, and the upper ends of the anchor bolts are connected to the connecting base plate. A first outer pouring layer is provided around the column base. A steel reinforcement cage is provided in the first outer pouring layer. The steel reinforcement cage includes several vertical steel bars and transverse steel bars connecting the vertical steel bars. The lower ends of the vertical steel bars are pre-embedded in the foundation. The vertical steel bars are distributed in a rectangular shape, including corner steel bars located at the four corners of the rectangle and intermediate steel bars set between the corner steel bars. The transverse steel bars include first transverse steel bars and second transverse steel bars set at intervals. The first transverse steel bars surround all the vertical steel bars, and the second transverse steel bars surround all the intermediate steel bars. A second outer pouring layer is provided above the first outer pouring layer and between it and the concrete steel column.

[0005] The concrete-steel column-foundation connection node of this utility model significantly improves the integrity of the node and the load transfer efficiency, and has the advantages of high seismic toughness and long service life maintenance. It is especially suitable for column-foundation connection of large-span and high-rise buildings.

[0006] As a further improvement of this utility model, a stiffening plate flush with the upper edge of the first outer pouring layer is provided inside the concrete steel column to enhance the local buckling resistance. The stiffening plate has an opening in the center to allow the welding gun to be inserted for welding, thereby improving work efficiency.

[0007] As a further improvement of this utility model, the upper end of the vertical steel bar has an inwardly bent downward flange, forming a "hook effect" to prevent the steel bar from slipping out of the concrete when under tension; the lower end has an outwardly bent horizontal edge with a hook-back section at the end of the outwardly bent horizontal edge. The smooth transition of the bent section reduces local stress concentration in the foundation concrete, increases the contact area with the foundation concrete, and improves the pull-out bearing capacity. In addition, the hook-back section at the end forms a mechanical lock to resist repeated loads under earthquakes or wind vibrations and prevent the steel bar from being pulled out of the foundation.

[0008] As a further improvement of this utility model, a secondary pouring layer is provided between the connecting base plate and the foundation, which allows for a small positional deviation when the foundation is pre-embedded with anchor bolts, thereby improving construction tolerance and connection reliability of the connection node.

[0009] As a further improvement of this utility model, transverse stirrups are provided between the upper and lower sides of the anchor bolt. By restraining the concrete around the anchor bolt, the crack expansion is limited under stress, thereby improving the tensile and shear bearing capacity and seismic ductility.

[0010] As a further improvement of this utility model, the concrete strength grades of the second outer pouring layer, the first outer pouring layer and the foundation are C20, C30 and C40, respectively. The C40 foundation ensures the bearing capacity, the C30 first outer layer balances the stress transfer, and the C20 second outer layer reduces the risk of shrinkage cracks, forming a strength gradient to adapt to the stress requirements and optimize costs.

[0011] As a further improvement of this utility model, the first outer casting layer has a height of 180cm and a thickness of 16cm, and the second outer casting layer has a height of 20cm and a thickness of 5cm, ensuring the reliability and stability of the connection. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the connection node between the concrete steel column and the foundation of this utility model.

[0013] Figure 2 for Figure 1 A top view of the location of the first outer pouring layer.

[0014] Among them, 1 is concrete steel column, 2 is foundation, 3 is stud, 4 is connecting base plate, 5 is anchor bolt, 6 is first outer layer, 7 is vertical reinforcement, 7A is angle reinforcement, 7A is intermediate reinforcement, 7B is horizontal reinforcement, 8A is first horizontal reinforcement, 8B is second horizontal reinforcement, 9 is second outer layer, 10 is stiffening plate, 11 is secondary layer, and 12 is horizontal stirrup. Detailed Implementation

[0015] like Figure 1-2The connection node between the concrete steel column 1 and the foundation 2 shown includes the concrete steel column 1 and the foundation 2. The steel column body of the concrete steel column 1 is prefabricated in the factory, while the internal concrete is poured on-site. The column base of the concrete steel column 1 is vertically fixed with studs 3 around its perimeter, and a connecting base plate 4 is welded to its bottom. Anchor bolts 5 are pre-embedded in the foundation 2, with their upper ends connected to the connecting base plate 4. A first outer pouring layer 6 is provided around the column base.

[0016] The first outer pouring layer 6 contains a reinforcing steel cage. The reinforcing steel cage includes several vertical reinforcing bars 7 and horizontal reinforcing bars 8 connecting the vertical reinforcing bars 7. The lower ends of the vertical reinforcing bars 7 are embedded in the foundation 2. The upper ends of the vertical reinforcing bars 7 have inwardly bent downward flanges, forming a "hook effect" to prevent the reinforcing bars from slipping out of the concrete when under tension; the lower ends have outwardly bent horizontal flanges with hooked ends. The smooth transition of the bent sections reduces local stress concentration in the foundation 2 concrete, increases the contact area with the foundation 2 concrete, improves the pull-out bearing capacity, and the hooked ends form a mechanical lock to resist repeated loads under earthquakes or wind vibrations, preventing the reinforcing bars from being pulled out of the foundation 2.

[0017] like Figure 2 As shown, the vertical reinforcing bars 7 are distributed in a rectangular pattern, including corner bars 7A at the four corners of the rectangle and intermediate reinforcing bars 7B placed between the corner bars 7A. The horizontal reinforcing bars 8 include first horizontal reinforcing bars 8A and second horizontal reinforcing bars 8B placed at intervals. The first horizontal reinforcing bars 8A surround all the vertical reinforcing bars 7, and the first horizontal reinforcing bars 8 surround all the intermediate reinforcing bars 7B. This reinforcing bar skeleton structure can form a gradient constraint effect, optimize the stress diffusion path, significantly improve shear bearing capacity and seismic ductility, and simultaneously suppress the risk of concrete cracking and crushing.

[0018] A second outer pouring layer 9 is provided above the first outer pouring layer 6 and between it and the concrete steel column 1. A stiffening plate 10, flush with the upper edge of the first outer pouring layer 6, is installed inside the concrete steel column 1 to enhance local buckling resistance. The stiffening plate 10 has a central opening, allowing a welding torch to be inserted for welding, improving work efficiency. A grouting hole is provided on one side of the concrete steel column 1 below the stiffening plate 10 to facilitate subsequent concrete pouring.

[0019] In this embodiment, the connection node between the concrete steel column and the foundation features a secondary pouring layer 11 between the connecting base plate 4 and the foundation 2. This allows for slight positional deviations when the foundation 2 is pre-embedded with anchor bolts 5, improving construction tolerance and connection reliability. Transverse stirrups 12 are provided above and below the anchor bolts 5 to constrain the concrete around them, limiting crack propagation under stress and improving tensile and shear strength as well as seismic ductility. The concrete strength grades of the second outer pouring layer 9, the first outer pouring layer 6, and the foundation 2 are C20, C30, and C40, respectively. The C40 foundation 2 ensures bearing capacity, the C30 first outer pouring layer balances stress transfer, and the C20 second outer pouring layer reduces the risk of shrinkage cracks, creating a strength gradient to adapt to stress requirements and optimize costs. The first outer pouring layer 6 has a height of 180cm and a thickness of 16cm, while the second outer pouring layer 9 has a height of 20cm and a thickness of 5cm, ensuring connection reliability and stability.

[0020] In summary, the concrete-steel column-foundation connection node of this embodiment significantly improves the integrity of the node and the load transfer efficiency, and has the advantages of high seismic toughness and long service life maintenance. It is especially suitable for column foundation connection of large-span, high-rise buildings.

[0021] This utility model is not limited to the above embodiments. Based on the technical solutions disclosed in this utility model, those skilled in the art can make some substitutions and modifications to some of the technical features without creative labor, and these substitutions and modifications are all within the protection scope of this utility model.

Claims

1. A connection node between a concrete steel column and a foundation, comprising a concrete steel column and a foundation, wherein the concrete steel column is vertically fixed with studs around its base and a connecting base plate is welded to its bottom, and anchor bolts are pre-embedded in the foundation, the upper ends of the anchor bolts being connected to the connecting base plate, characterized in that, The column base is surrounded by a first outer cast-in-place layer, within which a steel reinforcement cage is provided. The steel reinforcement cage includes several vertical steel bars and horizontal steel bars connecting the vertical steel bars. The lower ends of the vertical steel bars are embedded in the foundation. The vertical steel bars are distributed in a rectangular shape, including corner steel bars located at the four corners of the rectangle and intermediate steel bars placed between the corner steel bars. The horizontal steel bars include first horizontal steel bars and second horizontal steel bars arranged at intervals. The first horizontal steel bars surround all the vertical steel bars, and the second horizontal steel bars surround all the intermediate steel bars. A second outer cast-in-place layer is provided above the first outer cast-in-place layer and between it and the concrete steel column.

2. The concrete-steel column-to-foundation connection node of claim 1, wherein: A stiffening plate is provided inside the concrete steel column at the position corresponding to the upper edge of the first outer layer of the cast-in-place layer, and the stiffening plate has an opening in the center.

3. The concrete-steel column-to-foundation connection of claim 1, wherein: The vertical reinforcing bar has an inwardly bent downward flange at the upper end and an outwardly bent horizontal flange at the lower end, with a hook at the end of the outwardly bent horizontal flange.

4. The concrete-steel column-to-foundation connection of claim 1, wherein: A secondary pouring layer is provided between the connecting base plate and the foundation.

5. The concrete-to-steel column-to-foundation connection of claim 1, wherein: The anchor bolts are provided with transverse stirrups on the upper and lower sides respectively.

6. The concrete-to-steel column-to-foundation connection of claim 1, wherein: The concrete strength grades of the second outer pouring layer, the first outer pouring layer, and the foundation are C20, C30, and C40, respectively.

7. The concrete-to-steel column-to-foundation connection of any of claims 1-6, wherein: The first outer pouring layer has a height of 180cm and a thickness of 16cm, and the second outer pouring layer has a height of 20cm and a thickness of 5cm.

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