CN201059017Y - Covered slab joints for shear-type energy-dissipating beam-to-column connections in eccentrically braced structures - Google Patents

Abstract

The utility model discloses a cover plate node used for connecting a shear type energy-dissipating beam section and a column in an eccentric support structure, which comprises a frame column (1) and a frame beam (2). A wedge-shaped steel cover plate (3) is respectively welded on the upper and lower flanges of the upper and lower parts; the frame column (1) is connected to the web of the frame beam (2) with high-strength bolts (6) through the connecting plate (5), and the connecting plate (5) It is welded on three sides of the web of the frame beam (2). The utility model can remove the energy-dissipating beam section from the beam-column connection node at the column edge, and convert the shear-type energy-dissipating beam section directly connected to the column into the shear-type energy-dissipating beam section being connected with the beam-column rigid node, which not only ensures the The bending bearing capacity of the end is large enough, and it also ensures that the shear deformation of the energy-dissipating beam section is fully developed, so as to dissipate more earthquake energy and reduce the workload of post-earthquake repairs; at the same time, it is necessary to ensure that the construction process is simple and the cost is low. It is convenient for promotion and application.

Description

Covered slab joints for shear-type energy-dissipating beam-to-column connections in eccentrically braced structures

technical field

The utility model relates to a beam-column connecting node, in particular to a cover plate node used for connecting shear-type energy-dissipating beam sections and columns in eccentric support.

Background technique

The eccentrically braced steel frame system is a new type of lateral force-resisting structural system developed recently and suitable for buildings in high-intensity earthquake areas. Eccentric support refers to the form of support in which the centers of the horizontal bars, vertical bars, and diagonal bars of the frame do not intersect at one point. Energy-dissipating beam segments are divided into shear-type energy-dissipating beam segments and bending-type energy-dissipating beam segments. There are two types of beam-to-column connections in eccentrically braced structures: energy-dissipative beam-to-column connections and non-energy-dissipative beam-to-column connections. Among them, the energy-dissipating beam-column connection is further divided into two types: the shear-type energy-dissipating beam-column connection and the bending-type energy-dissipating beam-column connection.

Article 8.1.5 of my country's "Technical Regulations for Steel Structures of High-Rise Civil Buildings" (JGJ99-98) clearly states: In the design of joints, the structure of joints should avoid the use of connection forms that are highly restrained and prone to lamellar tearing. In addition, Article 8.2 of the "Code for Seismic Design of Buildings" (GB 50011-2001) also clearly stipulates the internal force and deformation analysis of multi-story and high-rise steel structures under earthquake action. The design requirements for bearing capacity are difficult to meet. Especially in the connection between the energy-dissipating beam section and the column of the eccentrically braced structure, the bending capacity of the beam end must be large enough to ensure that the energy-dissipating beam section fully develops shear plastic deformation in order to dissipate more seismic energy.

In order to ensure that the shear plastic deformation of the energy-dissipating beam section is fully developed so as to dissipate more seismic energy, and to meet the design requirements of stronger strong-column and weak-beam joints and the flexural bearing capacity of the beam end, it is generally necessary to adopt Some strengthening measures, the current common practices are shown in the accompanying drawings. The following briefly introduces the shortcomings of these common practices applied to eccentrically supported structures:

1. As shown in Figure 3, for the plan of adding a cover plate, since a large number of welds on the top of the flange may cause serious stress, strain concentration and weld defects, the bearing capacity of the structure will be reduced; due to the shear energy dissipation beam Usually, after the shear plastic hinge is formed in the web, the bending hinge will be formed at the beam end as the shear bearing capacity continues to increase. However, this scheme only strengthens the bending bearing capacity of the energy-dissipating beam section, and the web However, the slab has not been strengthened, so it will not be of great help to the improvement of the bearing capacity of the shear-type energy-dissipating beam and column connection in the eccentrically braced structure.

2. As shown in attached figure 4, although the ribbed plan can strengthen the beam-column joint and move the energy-dissipating beam section away from the column edge, a large number of welds between the flange of the T-shaped ribbed plate and the flange of the frame beam may cause serious damage. Stress, strain concentration and weld defects will reduce the bearing capacity of the structure; T-shaped ribbed plates are used to strengthen the joints between energy-dissipating beams and columns, which restricts the rotation of energy-dissipating beams too much, which is not conducive to energy-dissipating beams Fully develop the shear plastic deformation; when adopting the T-shaped stiffened plate scheme, it is necessary to add stiffeners at the corresponding positions of the frame columns as shown in Figure 4, which not only wastes steel, but also increases construction costs.

3. As shown in Figure 5, the short beam is welded to the column in the factory, and then the frame beam and the short beam are spliced at the construction site, which is not applicable to the direct connection between the energy-dissipating beam section and the column. Because if the splicing position of the frame beam and the short beam is in the energy-dissipating beam section, the high-strength bolt holes at the splicing place of the connecting plate will reduce the shear capacity of the web of the energy-dissipating beam section; if the splicing position of the frame beam and the short beam is in the Outside the energy-dissipating beam section, the required length of the short beam will be too long. On the one hand, it is not conducive to transportation. On the other hand, the flange of the frame beam needs to be cut from a whole steel plate, which will cause a great waste of steel. In addition, this scheme is similar to the strengthening scheme shown in Figure 3, only the bending capacity of the energy-dissipating beam section is strengthened, but the web is not strengthened, so the shear-type energy-dissipating beam section and column The increase in bearing capacity when connected won't help much.

4. As the dog-bone scheme shown in Figure 6, the relevant data show that it is very suitable for the connection of curved energy-dissipating beam sections and columns, but not necessarily suitable for the connection of shear-type energy-dissipating beam sections and columns, because It may reduce the rotational capacity of energy-dissipating beam segments; the quality of the welds at the frame beam flanges is the main factor determining the performance of dog-bone joints. In addition, this scheme is similar to the strengthening scheme shown in Figure 3, only the bending capacity of the energy-dissipating beam section is strengthened, but the web is not strengthened, so the shear-type energy-dissipating beam section and column in the eccentric support structure The increase in bearing capacity when connected won't help much.

5. As the prestressing scheme shown in accompanying drawing 7, 10 is a prestressing cable, and 11 is an anchorage. This scheme has high cost and complicated construction technology, so it is difficult to popularize and apply.

6. As shown in Figure 8, the notching scheme of the web plate can ensure the free connection of the flanges, but it greatly reduces the effective length of the energy-dissipating beam section, thereby reducing the rotation capacity of the energy-dissipating beam section.

Contents of the invention

The technical problem to be solved by the utility model is: to overcome the deficiencies of the prior art, provide a beam-column connection node that can move the energy-dissipating beam section away from the column edge, and convert the shear-type energy-dissipating beam section directly connected to the column into a shear joint. The tangential energy-dissipating beam section is connected with the beam-column rigid joints, which not only ensures that the flexural bearing capacity of the beam end is large enough, but also ensures that the energy-dissipating beam section fully develops shear deformation, so as to dissipate more seismic energy and reduce the The post-earthquake repair workload; at the same time, it is necessary to ensure that the construction process is simple, the cost is low, and it is easy to promote and apply.

In order to solve the above-mentioned technical problems, the utility model is realized in the following way: it comprises a frame column (1) and a frame beam (2), and a wedge-shaped steel cover plate (3) is respectively welded on the upper and lower flanges of the end of the frame beam (2) ; Use high-strength bolts (6) to connect the frame column (1) with the web of the frame beam (2) through the connecting plate (5). The improvement of the utility model is to connect the connecting plate (5) and the web of the frame beam (2) Welding on three sides of the board.

The width of the wedge-shaped steel cover plate (3) is 20-30mm narrower than that of the flange of the frame beam (2), the length is greater than 180mm or 0.3h _b , and the thickness is 6-8mm.

The thickness of the frame column stiffener (7) should be greater than or equal to the sum of the thickness of the flange of the frame beam (2) and the wedge-shaped steel cover plate (3).

The theoretical basis of the utility model is: from the internal force analysis, the key to the energy consumption of the energy-dissipating beam section is that the beam section must have a certain rotation capacity, so the non-energy-dissipating beam section, column and support pair directly connected with the energy-dissipating beam section Its constraints can also affect its energy dissipation capacity, which in turn affects the bearing capacity of the eccentric support structure. Even for the shear-type energy-dissipating beam, when the energy-dissipating beam is directly connected to the column, the end bending moment is very large, and it is possible that after the shear plastic hinge is formed, as the shear bearing capacity continues to increase, the The bending moment increases rapidly, and finally a bending hinge is formed, which easily produces lamellar tearing at the column flange, which not only reduces the bearing capacity of the overall structure, but also increases the post-earthquake repair workload. Therefore, when the shear-type energy-dissipating beam section is directly connected to the column, the beam-column connection node is strengthened, the energy-dissipating beam section is removed from the column edge, and the shear-type energy-dissipating beam section is directly connected to the column to convert the shear-type energy-dissipating beam section into a shear-type energy-dissipating beam section. The connection between the energy-dissipating beam section and the beam-column rigid joints not only ensures that the flexural bearing capacity of the beam end is large enough, but also ensures that the energy-dissipating beam section fully develops shear deformation, so as to dissipate more seismic energy and reduce the seismic load. Post-repair workload.

The beneficial effects of the utility model are:

This new joint form is used to connect the shear-type energy-dissipating beam to the column, which is equivalent to removing the shear-type energy-dissipating beam from the column edge, which can avoid the formation of shear hinges and bending hinges at the column edge, thus allowing the shear The type energy-dissipating beam section has a large rotation; the web is connected to the column through the connecting plate and high-strength bolts, and the installation and construction are very convenient; there is no need to add additional stiffeners to the column, which not only saves steel, but also reduces construction costs; The blanking of the whole steel plate is more economical; it can not only meet the design requirements of stronger joints of strong columns and weak beams and the bending capacity of beam ends, but also ensure that the shear-type energy-dissipating beam sections fully develop shear plastic deformation so as to dissipate more Earthquake energy; the improved method of adding a cover plate uses less material, and the flange strengthening measures can be completed in the factory. The construction process is simple, the cost is low, and it is easy to popularize and apply.

Description of drawings

Below in conjunction with accompanying drawing, the utility model is described in further detail.

Fig. 1 is a structural representation of the utility model;

Fig. 2 is the top view of Fig. 1 of the utility model;

Fig. 3 is the structural schematic view of adding a cover plate on the flange of the frame beam in the prior art;

Fig. 4 is a structural schematic diagram of ribbing on the flange of the frame beam in the prior art;

Fig. 5 is a structural schematic diagram of welding short beams on frame columns and widening the flanges of the short beams in the prior art;

Fig. 6 is a schematic diagram of making the frame beam flange into a dog-bone structure in the prior art;

Fig. 7 is the structural representation of prior art prestressing method;

Fig. 8 is a schematic diagram of the structure of slotting on the web of the frame beam in the prior art.

1-frame column, 2-frame beam, 3-wedge cover plate, 4-energy-dissipating beam section stiffener, 5-beam-column joint connection plate, 6-high-strength bolt, 7-frame column stiffener, 8-stiffener, 9-stiffened flange plate, 10-prestressed cable, 11-anchor.

Detailed ways

See accompanying drawing 1, accompanying drawing 2. A wedge-shaped steel cover plate (3) is respectively welded on the upper and lower flanges of the end of the frame beam (2) with a single-sided fillet weld; a connecting plate (5) is welded on the frame column (1) with a double-sided corner fillet weld ), and the high-strength bolts (6) holes connected to the web of the frame beam (2) are reserved on the connecting plate (5); at the construction site, the high-strength bolts (6) are first used to connect the frame column (1) to the connecting plate (5) The web of the frame beam (2) is connected, and then the connecting plate (5) and the web of the frame beam (2) are welded on three sides by single-side fillet welds; The upper and lower flanges of (2) are welded to the frame column (1).

The width of the wedge-shaped steel cover plate (3) is about 20-30mm narrower than the width of the flange of the frame beam (2), the length is not less than 180mm or 0.3h _b (frame beam height), and the thickness is 6-8mm. In addition, the thickness of the frame column stiffener (7) should be greater than or equal to the sum of the thickness of the flange of the frame beam (2) and the wedge-shaped steel cover plate (3).

The improved cover plate method not only strengthens the beam-column joint, but also removes the energy-dissipating beam section from the column edge, which can avoid the formation of shear hinges and bending hinges at the column edge, and allow the energy-dissipating beam section to have a large The rotation makes it fully develop shear plastic deformation, dissipate more seismic energy, and also reduce the post-earthquake repair workload.

Example

Part of the new joint form is processed in the factory, and part is welded on site. The specific implementation plan is as follows: a wedge-shaped steel cover plate 3 is welded on the upper and lower flanges of the end of the frame beam 2 with a single-sided fillet weld in the factory; In the factory, a connecting plate 5 is welded on the frame column 1 with double opposite corner fillet welds, and 6 holes for high-strength bolts connected to the web of the frame beam 2 are reserved on the connecting plate 5; The plate 5 connects the frame column 1 and the web of the frame beam 2, and then welds the connecting plate 5 and the web of the frame beam 2 on three sides by single-sided fillet welds; The upper and lower flanges of the beam 2 are welded to the frame column 1.

Claims (3)

1. A cover slab node used for connecting the shear type energy dissipation beam section and the column in the eccentric support structure, it includes the frame column (1) and the frame beam (2), and the upper and lower wings at the end of the frame beam (2) A wedge-shaped steel cover plate (3) is respectively welded on the edge; the frame column (1) and the web of the frame beam (2) are connected by high-strength bolts (6) through the connecting plate (5), and the feature is that the connecting plate (5 ) and the frame beam (2) are welded on three sides of the web. 2. The cover plate node for connecting the shear type energy dissipation beam section and the column in the eccentric support structure according to claim 1, characterized in that: the width of the wedge-shaped steel cover plate (3) is wider than that of the frame beam (2 ) The width of the flange is 20-30mm narrower, the length is greater than 180mm or 0.3h _b , and the thickness is 6-8mm. 3. The cover plate node for connecting the shear type energy dissipation beam section and the column in the eccentric support structure according to claim 1 or 2, characterized in that: the thickness of the frame column stiffener (7) should be greater than or It is equal to the sum of the thickness of the flange of the frame beam (2) and the thickness of the wedge-shaped steel cover plate (3).

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