CN105863081A - Multi-cavity concrete filled steel tube combination column and steel beam bolt joint and assembly method - Google Patents

Abstract

A multi-cavity steel pipe concrete composite column and steel beam bolt connection node and assembly method, including steel plates arranged on both sides of the multi-cavity steel pipe concrete composite column, the top of each steel plate is provided with a first ear plate, and the upper flange of the steel beam is provided with an upper cover The bottom of the lower flange is provided with a second ear plate, and the web of the steel beam is provided with two connecting angle steels, the upper cover plate is connected with the first ear plate, and the second ear plate is connected with the steel plate. The node of the present invention has a high degree of assembly, and the multi-cavity steel pipe concrete composite column, steel plate, steel beam, upper cover plate, second ear plate and connecting angle steel can all be prefabricated in the factory, which reduces the welding workload of installation, and only needs to be installed on site. Position the assembly. The node form is simple, the degree of assembly is high, and the installation is convenient and quick. Due to the avoidance of traditional penetration welding during on-site installation, traditional penetration welding tends to cause large welding residual stress on the steel, which makes the steel at the joints prone to delamination or brittle failure.

Description

Multi-cavity steel pipe concrete composite column and steel beam bolt connection node and assembly method

technical field

The invention relates to a structural system of a multi-cavity concrete-filled steel pipe composite column in the technical field of construction engineering, in particular to a connection node and an assembly method of a multi-cavity steel pipe concrete composite column and a steel beam bolt.

Background technique

The multi-cavity steel pipe concrete composite column composite structure system is a new type of steel pipe concrete composite column structure system that solves the problem of protruding column feet in residential systems. It has the advantages of high bearing capacity, good plasticity and toughness, and convenient construction.

At present, my country's "Technical Regulations for Rectangular Concrete-filled Steel Tube Structures" (GECS159: 2004) provides steel-beam joints for concrete-filled steel tube composite columns, which mainly include inner diaphragm type and outer ring plate type. But so far, there are the following deficiencies in the connection between the steel pipe concrete composite column and the steel beam node in the prior art:

(1) When the inner diaphragm and the flange of the beam in the inner diaphragm joint are in the same horizontal plane, the joint meets the requirements of rigid joints, but this kind of joint can only be used when the side of the pipe column is long. Because when the side length is small, it is not only difficult to weld, but also hinders the concrete pouring in the pipe. In addition, the beam flange and the inner partition plate penetrate the weld on both sides of the same column wall, and the steel produces a large welding residual stress, which makes the steel at the joint easy to produce Delamination or brittle failure.

(2) Affect the appearance and use of the building. Such as the outer ring plate joint, the construction of this joint is simple, the force transmission is clear, and it is not limited by the side length of the steel pipe, but a sufficiently large horizontal ring plate is required to ensure the strength of the joint, and the amount of steel used is larger than that of the inner diaphragm joint. And when applied to corner columns, the horizontal ring plate not only hinders the installation of wall panels, but also causes the reinforcing ring to protrude from the building facade, causing convex corners at the indoor and outdoor nodes, which affects the look and feel, which needs to be solved by decoration or ceiling.

(3) The mechanical properties of joints and the simplicity and economy of construction cannot be both. In practical applications, some types of joints have better mechanical properties and overall stiffness of the joints, but the amount of materials used is large and the construction is complicated.

Contents of the invention

Aiming at the deficiencies of the prior art, the present invention provides a multi-cavity concrete-filled steel tube composite column and a steel beam bolt connection node and an assembly method. By adopting the separation of the beam end and the column wall edge and the full-height side plate, the "strong column and weak beam" are satisfied. , strong nodes and weak components" design principle, the joint structure is simple, the force transmission is clear, and the assembly degree is high.

In order to achieve the above object, the present invention is achieved through the following technical solutions.

Multi-cavity concrete-filled steel pipe composite column and steel beam bolt connection node, including steel plates arranged on both sides of the multi-cavity steel pipe concrete composite column, the top of each steel plate is provided with a first ear plate, the upper flange of the steel beam is provided with an upper cover plate, and the lower flange The bottom is provided with a second ear plate, the web of the steel beam is provided with two connecting angle steels, the upper cover plate is connected with the first ear plate, and the second ear plate is connected with the steel plate.

The multi-cavity steel pipe concrete composite column includes hidden columns located at both ends, parallel webs are arranged between the two hidden columns, and the webs are connected by partitions.

The steel plate is arranged on the multi-cavity steel pipe concrete composite column through the welding seam.

The upper cover plate is connected with the steel plate through bolts.

The first ear plate is connected to the steel plate through a fillet weld, and the second ear plate is connected to the lower flange of the steel beam through a fillet weld.

Positioning holes are provided on each steel plate, holes are provided on the connecting angle steel, and the steel plate and the connecting angle steel are fixed by bolts.

The steel beam is an I-shaped steel beam.

The ends of the I-beams are provided with stiffeners.

An assembly method for the joint connection between multi-cavity concrete-filled steel pipe composite columns and steel beam bolts. First, the steel plates are fixed on both sides of the multi-cavity steel pipe concrete composite columns through welding seams, and then the first lug plate is welded on the top of each steel plate to obtain a prefabricated The multi-cavity steel pipe concrete composite column; the upper cover plate is set on the upper flange of the I-steel beam, the second ear plate is welded on the lower flange of the I-steel beam, and the two connecting angle steels are set at the web of the I-steel beam to obtain Prefabricated steel beams; then transport the prefabricated multi-cavity concrete-filled steel pipe composite columns and steel beams to the site, pour concrete into the multi-cavity steel pipe concrete composite columns, and then hoist the prefabricated steel beams to the joints from top to bottom area, so that the upper cover plate is in contact with the first ear plate, and then the first ear plate and the upper cover plate are fixed with bolts, the connecting angle steel is fixed with the steel plate, and the second ear plate is fixed with the steel plate to complete the assembly.

Compared with the prior art, the beneficial effects of the present invention are reflected in:

(1) The present invention arranges the first ear plate on the steel plates on both sides of the combined column, sets the upper cover plate on the upper flange of the steel beam, and arranges the second ear plate on the lower flange of the steel beam, and passes the upper cover plate and the first ear plate Connection, the second lug plate is connected with the steel plate, the joint connection mode of the multi-cavity concrete filled steel pipe column and the steel beam double side plate rigid connection and the force transmission method are unique, due to the separation of the beam end from the column wall and the use of the full height side plate. The physical isolation between the beam and the column changes the force transmission path of the traditional joint, eliminates the triaxial stress concentration, not only enables the plastic hinge to move outward from the joint to the beam, but also eliminates the tear damage and damage of the traditional joint column flange. Deficiencies in the dependency of the joint rotational capacity on the weak plate area of the column web. Meet the design and principles of "strong columns and weak beams, strong nodes and weak members".

(2) Due to the use of full-height steel plates, the integrity of the multi-cavity concrete-filled steel tube composite column is maintained, making it more convenient to pour concrete in the steel tube, and it is easy to ensure the quality of concrete pouring in the node area.

(3) Since the steel girder transmits the bending moment and shear force to the double side plate (ie steel plate) only through the upper cover plate, the second lug plate and the connecting angle steel, the steel girder can be separated from the column end, reducing the net span of the steel girder , can reduce the height of steel beams to a certain extent, and meet the needs of residential users for residential functions.

(4) The joint assembly degree of the present invention is high, and the multi-cavity steel pipe concrete composite column, steel plate, steel beam, upper cover plate, second ear plate and connecting angle steel can all be prefabricated in the factory, reducing the welding workload of installation, and the on-site Installation simply requires positioning of the assembly. The node form is simple, the degree of assembly is high, and the installation is convenient and quick. Due to the avoidance of traditional penetration welding during on-site installation, traditional penetration welding tends to cause large welding residual stress on the steel, which makes the steel at the joints prone to delamination or brittle failure.

The nodes of the invention are all connected by high-strength bolts when installed on site, so the degree of assembly is high, and the node connections are reliable.

Furthermore, since the side plate and the CFST composite column are only connected by welds on the outer column wall, and there are no welds inside the CFST, the structure of this joint is simple and the stress is reasonable compared with the traditional joint.

Description of drawings

Fig. 1 is the schematic diagram of prefabricated multi-cavity concrete filled steel tube composite column;

Figure 2 is a schematic diagram of a prefabricated steel beam.

Fig. 3 is a schematic diagram of assembly of the present invention.

Figure 4 is a schematic diagram of the yielding of the upper and lower flanges of the beam.

Figure 5 is a schematic diagram of the plastic hinge at the end of the beam.

Figure 6 is a schematic diagram of cover damage.

Figure 7 is a schematic diagram of the final destruction.

Figure 8 is a hysteresis curve diagram.

In the figure, 1 is a multi-cavity steel pipe concrete composite column, 2 is a steel beam, 3 is a steel plate, 4 is an upper cover plate, 5 is a first ear plate, 6 is a connecting angle steel, 7 is a bolt, and 8 is a second ear plate.

detailed description

Below in conjunction with accompanying drawing, the embodiment of the present invention is described in detail: present embodiment implements under the premise of the technical scheme of the present invention, has provided detailed implementation mode and concrete operation process, but protection scope of the present invention is not limited to the following the embodiment.

Referring to Fig. 3, the present invention includes steel plates 3 arranged on both sides of the multi-cavity concrete-filled steel pipe composite column, that is, two steel plates are arranged on both sides of the multi-cavity steel pipe concrete composite column, and the top of each steel plate 3 is provided with a first ear plate 5, and the first ear plate 5 is arranged on the top of each steel plate 3. An ear plate 5 is connected to the steel plate 3 through a fillet weld, and the steel plate 3 is set on the multi-cavity steel pipe concrete composite column through the weld.

The upper flange of the steel beam is provided with an upper cover plate 4, the upper cover plate 4 is connected with the steel plate 3 through a fillet weld, the upper cover plate 4 is connected with the first ear plate 5 through bolts 7, and the bottom of the lower flange of the steel beam is provided with a second ear plate 8, and the second ear plate 8 is connected to the lower flange of the steel beam through a fillet weld; two connecting angle steels 6 are arranged at the web of the steel beam, and the connecting angle steel 6 is connected to the steel plate 3 through bolts, and the bolt 7 is used to connect the first The two ear plates 8 are connected to the steel plate. In the present invention, the steel girder is connected to the outstretched ends of the steel plates 3 on both sides of the multi-cavity steel pipe concrete composite column through the upper cover plate, the first reinforcing rib and the second reinforcing rib.

The multi-cavity steel pipe concrete composite column in the present invention includes hidden columns located at both ends, parallel webs are arranged between the two hidden columns, and the webs are connected by partitions, and concrete is poured into them.

Each steel plate 3 is provided with a positioning opening, and the connecting angle steel 6 is provided with a hole, and the bolt 7 passes through the positioning opening on the steel plate and the hole on the connecting angle steel to fix the steel plate and the connecting angle steel.

The steel beam is an I-shaped steel beam, and stiffeners are arranged at the ends of the steel beam.

The above-mentioned assembly method of the multi-cavity concrete-filled steel pipe composite column and the steel beam bolt connection node is shown in Fig. 1, and holes are opened in the steel plate according to the design position in advance, and then the steel plate 3 is fixed on both sides of the multi-cavity steel pipe concrete composite column through welding seams, and then the The first ear plate 5 is arranged on the top of each steel plate to obtain a prefabricated multi-cavity steel pipe concrete composite column; referring to Figure 2, holes are first opened on the connecting angle steel 6, and then the upper cover plate 4 is welded to the I-shape with stiffening ribs On the upper flange of the steel beam, set the second ear plate 8 on the lower flange of the I-shaped steel beam, and arrange the two connecting angle steels 6 at the web of the I-shaped steel beam to obtain a prefabricated steel beam; see Figure 3, and then place the The prefabricated multi-cavity concrete-filled steel pipe composite columns and steel beams are transported to the site. The first ear plate 5 is in contact, and then the first ear plate 5 is fixed to the upper cover plate 4 by reinforcing bolts 7, the connecting angle steel 6 is fixed to the steel plate 3, and the second ear plate 8 is fixed to the steel plate 3 to complete the assembly.

In the present invention, the steel plate can be prefabricated in the factory and welded on both sides of the multi-cavity steel pipe concrete composite column according to the positioning, and the first ear plate is arranged on the top of each steel plate 3 . Prefabricate the steel beam, upper cover plate and connecting angle steel in the factory first, then weld the upper cover plate to the upper flange of the steel beam according to the designed size and weld the second lug plate to the lower flange of the steel beam according to the designed size in the factory. The connecting angle steel is welded at the web of the steel beam according to the positioning size. The above process is prefabricated in the factory in advance, which saves the inconvenience of on-site production and improves the efficiency. During on-site installation, the steel beam is hoisted from top to bottom and positioned at the joint area, and the steel plates connecting the angle steel and the two sides of the multi-cavity steel pipe concrete composite column are connected by high-strength bolts to fix the position of the steel beam.

The inventive joint has two major innovations: the separation of the beam ends from the column flanges and the use of full height side panels. The physical isolation between the beam and the column changes the force transmission path of the traditional joint, eliminates the triaxial stress concentration, not only enables the plastic hinge to move outward from the joint to the beam, but also eliminates the tear damage and damage of the traditional joint column flange. Deficiencies in the dependency of the joint rotational capacity on the weak plate area of the column web. Meet the design and principles of "strong columns and weak beams, strong nodes and weak members". At the same time, the node can be divided into two parts and prefabricated in the factory respectively. On-site installation only needs simple assembly, and the node structure is simple and highly assembling.

The failure modes of the present invention and the seismic performance of the nodes are described below.

The mechanical properties of the new type of joints are described by taking multi-cavity steel pipe concrete composite column-steel beam U-shaped rigid joints as a column. Using ABAQUS software to conduct finite element analysis on the joints, the joint column is a 200x600 multi-cavity concrete-filled steel pipe composite column, the beam is made of H350x150x6x10 welded I-beam, and the thickness of both side plates and cover plates at the joint is the same as that of the beam flange. The results of finite element analysis are as follows.

1. Destruction mode

The multi-cavity steel pipe concrete composite column-steel beam rigid connection node of the present invention adopts the multi-cavity steel pipe concrete composite column, the steel pipe has a strong restraint effect on the concrete, and the overall bearing capacity and ductility of the column body are relatively good, realizing strong Design requirements for column-weak beams, strong joints and weak members. The destruction sequence of the connection nodes of the present invention is shown in Figures 4-8. (1) When the horizontal external force acts, the upper and lower flanges of the beam ends in the joint area first enter into plasticity, while the cover plate and side plate except a small part of the stress concentration area yield, the steel in most other areas is still in the elastic stage (as shown in Figure 4 ). (2) As the external force increases, plastic hinges first appear at the end of the beam before other parts (as shown in Figure 5). At this time, the steel in some areas of the cover plate yields and enters the plastic stage, while the side plate except for a small part of the stress concentration area, most of the Regional steel is still in the elastic phase. (3) Due to the strengthening effect of the steel material, when the external force load continues to increase, the steel plate in the connection area between the two sides of the cover plate and the side plate yields in shear, and the steel enters the plastic development stage. At this time, most of the joint side plate is still in the elastic stage , only a small part of the stress concentration of the steel plate yields (as shown in Figure 6). (4) As shown in Figure 7, as the load continues to increase, the structure eventually fails. At this time, the upper and lower flanges of the beam end buckle, but only part of the side plate enters the plastic stage, and most of the side plates in the joint area are still in the elastic stage .

2. Seismic performance of nodes

According to the principle of seismic concept design, the structure should have multiple seismic fortification lines to avoid the damage of the whole system due to the damage of some components. At the same time, it is also required that the structure should have the necessary strength, good deformation capacity and energy dissipation capacity. The rigid connection node of the present invention adopts the method of isolating the column and the beam end, and transmits the beam end bending moment and shear force through the node connector composed of the full-height side plate and the cover plate.

Due to the above failure sequence, when an earthquake acts, a plastic hinge first appears at the end of the beam, which consumes a certain amount of seismic energy, and then the cover plate shears and yields to further dissipate the seismic energy. , most are still in the elastic stage. The overall structure meets the design principle of "strong columns and weak beams, strong nodes and weak members".

Ductility refers to the ability of a structure to withstand inelastic deformation without a significant reduction in its bearing capacity before failure. In the seismic design of structures, the ductility index is an important characteristic. The interstory displacement angle of multi-cavity steel pipe concrete composite column-steel beam U-shaped rigid joint is 7%-10%, which meets the requirements of my country's code.

When a structure is under seismic action, the structure has a continuous process of energy absorption and dissipation. When the structure enters the elastic-plastic state, its seismic performance mainly depends on the energy dissipation capacity of the components. The area enclosed by the curve in the loading stage in the hysteresis curve can reflect the amount of energy absorbed by the structure; while the area enclosed by the unloading curve and the loading curve is the dissipated energy. These energies are converted into heat energy and dissipated into space through internal friction or local damage of the material. The more energy that is dissipated, the less likely it is that the structure will fail. Due to the above-mentioned node failure sequence, the beam end and the cover plate successively dissipate a large amount of seismic energy, which finally ensures that the node has a better energy dissipation capacity. As shown in Figure 8, the hysteresis curve of the node is full, without obvious pinching phenomenon, and dissipates a large amount of seismic energy. The energy dissipation capacity of the node is good, and it has strong seismic performance.

Claims (9)

1. The joint between the multi-cavity concrete-filled steel pipe composite column and the steel beam bolt is characterized in that it includes steel plates (3) arranged on both sides of the multi-cavity steel pipe concrete composite column, and the top of each steel plate (3) is provided with a first ear plate ( 5), the upper flange of the steel beam is provided with an upper cover plate (4), the bottom of the lower flange is provided with a second ear plate (8), the web of the steel beam is provided with two connecting angle steels (6), and the upper cover plate (4 ) is connected with the first ear plate (5), and the second ear plate (8) is connected with the steel plate (3). 2. The multi-cavity concrete-filled steel pipe composite column and the steel beam bolt connection node according to claim 1, wherein the multi-cavity concrete-filled steel pipe composite column includes concealed columns positioned at both ends, and a phase gap is arranged between the two concealed columns. Parallel webs are connected by partitions. 3. The multi-cavity concrete-filled steel tube composite column and steel beam bolt connection node according to claim 1, characterized in that the steel plate (3) is arranged on the multi-cavity steel tube concrete composite column through a weld seam. 4. The multi-cavity concrete-filled steel tube composite column and steel beam bolt connection node according to claim 1, characterized in that the upper cover plate (4) is connected to the steel plate (3) by bolts. 5. The multi-cavity steel pipe concrete composite column and steel beam bolt connection node according to claim 1, characterized in that, the first ear plate (5) is connected to the steel plate (3) through a fillet weld, and the second ear plate (8) It is connected to the lower flange of the steel beam through a fillet weld. 6. multi-cavity steel pipe concrete composite column and steel beam bolt connection node according to claim 1, is characterized in that, each steel plate (3) is provided with positioning openings, and the connecting angle steel (6) is provided with holes, Fix the steel plate and connecting angle steel by bolts (7). 7. The multi-cavity concrete filled steel pipe composite column and steel beam bolt connection node according to claim 1, characterized in that the steel beam is an I-shaped steel beam. 8 . The multi-cavity concrete filled steel pipe composite column and steel beam bolt connection node according to claim 7 , characterized in that, the end of the I-shaped steel beam is provided with a stiffener. 9. An assembly method for a multi-cavity concrete-filled steel pipe composite column and a steel beam bolt connection node, characterized in that the steel plate (3) is first fixed on both sides of the multi-cavity steel pipe concrete composite column through weld seams, and then placed on the top of each steel plate Weld the first ear plate (5) to obtain the prefabricated multi-cavity steel pipe concrete composite column; set the upper cover plate (4) on the upper flange of the I-beam, and weld the second ear plate (8) on the lower flange of the I-beam ), set two connecting angle steels (6) at the web of the I-beam to obtain the prefabricated steel beam; In the steel tube concrete composite column, the prefabricated steel beam is hoisted to the joint area from top to bottom, so that the upper cover plate (4) is in contact with the first lug plate (5), and then the first lug plate (5) is connected with the bolt (7). The plate (5) is fixed with the upper cover plate (4), the connecting angle steel (6) is fixed with the steel plate (3), the second ear plate (8) is fixed with the steel plate (3), and the assembly is completed.