CN106013466A - Double-side-plate joint in bolted connection and assembling method - Google Patents

Abstract

A bolt-connected double-sided slab node and an assembly method, including a first steel plate and a second steel plate arranged on both sides of a multi-cavity steel pipe concrete composite column, the first steel plate and the second steel plate are arranged in parallel; the upper flange and the lower flange of the steel beam Both sides are provided with several ear plates, the ear plates are connected with the first steel plate and the second steel plate, and connecting angle steels are arranged symmetrically on both sides of the web of the steel beam. 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, lug plate, and connecting angle steel can all be prefabricated in the factory, reducing the welding workload of installation, and the on-site installation only needs to be positioned and assembled. 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 they are installed on site, so the degree of assembly is high, and the node connections are reliable.

Description

A bolt-connected double-sided plate joint and its assembly method

technical field

The invention relates to a multi-cavity steel pipe concrete composite column structure system in the technical field of construction engineering, in particular to a bolt-connected double-side plate node and an assembly method.

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 bolt-connected double-sided plate 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 requirements of "strong column and weak beam, strong node and weak member" are met. "The design principle, the node 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.

A bolt-connected double-sided plate joint, comprising a first steel plate and a second steel plate arranged on both sides of a multi-cavity steel pipe concrete composite column, the first steel plate and the second steel plate are arranged in parallel; both sides of the upper and lower flanges of the steel beam are A plurality of ear plates are arranged, and the ear plates are connected with the first steel plate and the second steel plate, and connecting angle steels are arranged symmetrically on both sides of the web plate of the steel beam.

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.

Both the first steel plate and the second steel plate are welded to the multi-cavity steel pipe concrete composite column through weld seams.

Two parallel ear plates are arranged along the length direction on both sides of the upper flange of the steel beam, and two parallel ear plates are arranged along the length direction on both sides of the lower flange of the steel beam.

The first steel plate, the second steel plate and the ear plate are all provided with holes, the ear plate on one side of the steel beam is connected to the first steel plate by bolts, and the ear plate on the other side of the steel beam is connected to the second steel plate by bolts.

The steel beam is an I-shaped steel beam.

The ends of the steel beams are provided with stiffeners.

An assembly method for bolt-connected double-sided slab joints, in which a first steel plate and a second steel plate parallel to each other are arranged on both sides of a multi-cavity concrete-filled steel tube composite column through welds to obtain a prefabricated multi-cavity steel tube concrete composite column; Two parallel ear plates are arranged along the length direction on both sides of the upper flange of the beam, two parallel ear plates are arranged along the length direction on both sides of the lower flange of the steel beam, and connecting angle steels are arranged symmetrically on both sides of the web of the steel beam. 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-filled concrete composite columns, and then hoist the prefabricated steel beams to the joint area, pass High-strength bolts connect the ear plate on one side of the steel beam with the first steel plate, and the ear plate on the other side with the second 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 is by arranging the first steel plate and the second steel plate on both sides of the composite column, and the first steel plate and the second steel plate are parallel, and a plurality of ear plates are set on the upper flange and the lower flange of the steel beam, by placing The ear plates on both sides of the steel beam are connected with the first steel plate and the second steel plate to complete the assembly of the column-beam joints. In the present invention, the connection mode and force transmission mode of the multi-cavity steel pipe concrete column and the steel beam double-side plate rigid connection node are unique. Separation of beam ends from column walls and 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".

(2) Due to the use of full-height double-sided slabs (i.e., the first steel plate and the second steel plate), the multi-cavity concrete-filled steel tube composite column maintains its integrity, making it more convenient to pour concrete inside the steel tube, and it is easy to ensure the quality of concrete pouring in the node area.

(3) Since the steel beam only transmits the bending moment and shear force to the first steel plate and the second steel plate through the ear plate and the connecting angle steel, the steel beam can be separated from the column end, which reduces the net span of the steel beam and can reduce the The height of the steel beams meets the needs of residential users for residential functions.

(4) The nodes of the present invention have a high degree of assembly. Multi-cavity steel tube concrete composite columns, steel plates, steel beams, ear plates, and connecting angles can all be prefabricated in the factory, reducing the welding workload of installation, and only need to be positioned and assembled for on-site installation. 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 they are installed on site, so the degree of assembly is high, and the node connections are reliable.

Furthermore, since the first steel plate, the second steel 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 traditional joints.

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 first steel plate, 4 is a second steel plate, 5 is an ear plate, and 6 is a connecting angle steel.

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 the first steel plate 3 and the second steel plate 4 arranged on both sides of the multi-cavity steel pipe concrete composite column, that is, two steel plates are arranged on both sides of the multi-cavity steel pipe concrete composite column, the first steel plate 3 and the second The steel plates 4 are arranged in parallel; two parallel ear plates 5 are arranged along the length direction on the top of the upper flange of the steel beam, and two parallel ear plates 5 are arranged along the length direction on the bottom of the lower flange of the steel beam; the first steel plate 3 and the second steel plate 3 Holes are provided on the ear plates 5, the ear plates 5 on one side of the steel beam are connected to the first steel plate 3 by bolts, and the ear plates 5 on the other side are connected to the second steel plate 4 by bolts.

In the present invention, the steel beam is connected to the outstretched ends of the first steel plate and the second steel plate on both sides of the multi-cavity steel pipe concrete composite column through the first steel plate and the second steel plate.

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

The steel beam is an I-shaped steel beam, and the end of the steel beam connected to the multi-cavity steel pipe concrete composite column is provided with a stiffener.

The above-mentioned assembly method of a double-sided plate joint connected by bolts, referring to Fig. 1, positions holes on the first steel plate and the second steel plate in advance according to the design, and then fixes the first steel plate 3 and the second steel plate 4 on the On both sides of the multi-cavity concrete-filled steel tube composite column, the first steel plate 3 and the second steel plate 4 are parallel to obtain a prefabricated multi-cavity steel tube concrete composite column; see Fig. Ear plate 5, two parallel ear plates 5 are arranged along the length direction at the bottom of the lower flange of the steel beam, and connecting angle steel 6 is arranged symmetrically on both sides of the web plate of the steel beam, that is, one connecting angle steel 6 is arranged on one side of the web plate of the steel beam , to obtain the prefabricated steel beams; see Figure 3, 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-concrete composite columns, and then place the prefabricated steel beams from Hoist up and down to the node area, connect the ear plate 5 on one side of the steel beam to 5 through bolts, and connect the ear plate 5 on the other side of the steel beam to the second steel plate 4 through bolts to complete the assembly.

In the present invention, the first steel plate and the second 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. Prefabricate the steel beam and connecting angle steel in the factory first, then weld the lug plate on the upper and lower flanges of the steel beam according to the design size in the factory, and then open threaded holes on the ear plate according to the design size, and position the connecting angle steel according to the position The size is welded at the web of the steel beam. 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 ear plate is connected with the first steel plate and the second steel plate 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 nodes and weak members. The destruction sequence of the connecting nodes of the present invention is shown in Figures 4-7. (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 (8)

1. a bolt-connected double-sided slab node, is characterized in that, comprises the first steel plate (3) and the second steel plate (4) that are arranged on both sides of multi-cavity steel pipe concrete composite column, the first steel plate (3) and the second steel plate (4) The two steel plates (4) are arranged in parallel; several ear plates (5) are arranged on both sides of the upper and lower flanges of the steel beam, and the ear plates (5) are connected with the first steel plate (3) and the second steel plate (4). Both sides of the web are symmetrically provided with connecting angle steels (6). 2. A bolt-connected double-sided slab node according to claim 1, wherein the multi-cavity concrete-filled steel tube composite column includes hidden columns located at both ends, and parallel webs are arranged between the two hidden columns. The plates and webs are connected by partitions. 3. A bolt-connected double-sided slab node according to claim 1, characterized in that, the first steel plate (3) and the second steel plate (4) are all welded to the multi-cavity steel pipe concrete composite column through weld seams superior. 4. A bolt-connected double-sided plate node according to claim 1, characterized in that two parallel ear plates (5) are arranged along the length direction on both sides of the upper flange of the steel beam, and the lower flange of the steel beam Two parallel ear plates (5) are arranged along the length direction on both sides. 5. A bolt-connected double-sided plate joint according to claim 1, characterized in that holes are provided on the first steel plate (3), the second steel plate (4) and the lug plate (5), The ear plate (5) on one side of the steel beam is connected to the first steel plate (3) by bolts, and the ear plate (5) on the other side of the steel beam is connected to the second steel plate (4) by bolts. 6. A bolted double-sided plate node according to claim 1, wherein the steel beam is an I-shaped steel beam. 7. A bolted joint with side plates for eccentric beam-columns according to claim 6, characterized in that stiffeners are provided at the ends of the steel beams. 8. An assembly method of a bolt-connected double-sided slab node, characterized in that, the first steel plate (3) and the second steel plate (4) parallel to each other are set by welds on both sides of the multi-cavity concrete-filled steel tube composite column to obtain Prefabricated multi-cavity steel pipe concrete composite column; two parallel ear plates (5) are arranged along the length direction on both sides of the upper flange of the steel beam, and two parallel ear plates are arranged along the length direction on both sides of the lower flange of the steel beam (5), connecting angle steels (6) are arranged symmetrically on both sides of the web of the steel beam to obtain the prefabricated steel beam; then the prefabricated multi-cavity concrete-filled steel tube composite columns and steel beams are transported to the site, and the concrete is poured in In the multi-cavity steel pipe concrete composite column, the prefabricated steel beam is hoisted to the joint area, and the ear plate (5) on one side of the steel beam is connected to the first steel plate (3) through high-strength bolts, and the ear plate ( 5) Connect with the second steel plate (4) to complete the assembly.