Buckling-restrained brace joint for reinforcing existing concrete frame structure

Abstract

The invention discloses a buckling-restrained brace joint for reinforcing an existing concrete frame structure, and relates to the technical field of damping of civil engineering structures. The existing buckling-restrained brace node is easy to generate an opening and closing effect under the action of an earthquake, so that an attachment welding seam of a node plate is fractured too early. The anti-buckling supporting structure comprises a gusset plate used for being connected with the anti-buckling supporting structure, and is characterized by further comprising two sliding mechanisms used for releasing tangential force borne by the gusset plate, the lower flange of the gusset plate is connected with a reinforced concrete frame beam through one sliding mechanism, and the lower flange of the gusset plate is connected with the reinforced concrete frame beam through the other sliding mechanism. The left flange of the gusset plate is connected with the reinforced concrete frame column through the other sliding mechanism, and when the gusset plate is subjected to tangential force, the gusset plate can move in the length direction of the reinforced concrete frame beam or the length direction of the reinforced concrete frame column through the two sliding mechanisms so as to release the tangential force transmitted by the buckling-restrained brace structure. The connecting structure is mainly used for connecting the beam column and the buckling-restrained brace.

Description

Technical Field

[0001] The invention relates to the technical field of shock absorption of civil engineering structures, and in particular to an anti-buckling support node for reinforcing an existing concrete frame structure. Background Art

[0002] Reinforced concrete frame structure is one of the most widely used structural systems. It is made of concrete and steel bars poured on site through formwork. Existing structures need to be reinforced to ensure their use due to reasons such as long construction age, aging of material properties, or failure to consider the structure's ability to resist severe earthquakes during construction.

[0003] The existing frame structure reinforcement generally adopts seismic isolation or energy dissipation reinforcement, that is, adding seismic isolation layer or energy dissipation damper on the original basis. This method has obvious effect on reducing seismic effect and can greatly improve the seismic performance of the structure. Buckling-resistance braces (BRBs) have been widely used at home and abroad because of their good seismic performance. At the same time, as a lateral force-resistant component, buckling-resistance braces have high economic efficiency in terms of cost, construction difficulty and full life cycle maintenance, which makes the application of BRBs in building structures gradually increase. Buckling-resistance braces (BRBs) are generally connected to existing reinforced concrete frame structures through node plates welded to the flanges of beams and columns. Under the action of earthquakes, beams and columns of traditional braced frame structures will produce significant bending deformation, while the rigid domain effect of the node plate constrains the free development of beam and column deformation. Therefore, additional forces (called opening and closing effects) are generated at the connection welds between the flanges of beams and columns and the node plates, resulting in premature fracture of the connection welds of the node plates, making the node plate connection a weak link instead, violating the seismic design principle of "strong node and weak component", and failing to ensure the full play of the energy dissipation capacity of buckling-resistance braces. Summary of the invention

[0004] In view of this, the present invention provides a buckling-restrained brace node for reinforcing an existing concrete frame structure, which can release the tangential action transmitted by the buckling-restrained brace (BRB) through the horizontal rolling of a roller shaft to prevent the opening and closing effect at the connection weld between the node plate and the reinforced concrete beam-column.

[0005] The technical solution adopted by the present invention to solve the above technical problems is:

[0006] A buckling-resistance brace node for reinforcing an existing concrete frame structure comprises a node plate for connecting the buckling-resistance brace structure, and is characterized in that it also comprises a sliding mechanism for releasing the tangential force exerted on the node plate, wherein two sliding mechanisms are provided, the lower flange of the node plate is connected to the reinforced concrete frame beam via one of the sliding mechanisms, and the left flange of the node plate is connected to the reinforced concrete frame column via the other sliding mechanism, and when the node plate is subjected to the tangential force, the two sliding mechanisms can make the node plate move along the length direction of the reinforced concrete frame beam or along the length direction of the reinforced concrete frame column to release the tangential force transmitted by the buckling-resistance brace structure.

[0007] Furthermore, each sliding mechanism includes a groove cover plate and a roller shaft. There are multiple roller shafts and they are evenly divided into two groups. The two groups of roller shafts are respectively arranged on the upper and lower sides of the reinforced concrete frame beam. There are two groove cover plates. The two groove cover plates are relatively arranged on the upper and lower sides of the reinforced concrete frame beam and clamp the two groups of roller shafts. The reinforced concrete frame beam has a plurality of groove holes penetrating the upper and lower surfaces. Each groove cover plate has a plurality of through holes. The through holes on the groove cover plate correspond to the groove holes on the reinforced concrete frame beam one by one and are connected by long bolts. The diameter of the groove holes is larger than the outer diameter of the studs in the long bolts, so that the groove cover plate can move in the horizontal direction of the reinforced concrete frame beam; the lower flange of the node plate is connected to the groove cover plate on the upper side of the reinforced concrete frame beam. When the node plate is subjected to tangential force, the groove cover plate moves with the node plate, and the roller shaft rolls along the length direction of the reinforced concrete frame beam to release the tangential force exerted on the node plate.

[0008] Furthermore, each sliding mechanism also includes an outer iron sheet, which is wrapped around the reinforced concrete frame beam and connected to the reinforced concrete frame beam through an adhesive material. Through holes are opened on the outer iron sheet at positions corresponding to the slots of the reinforced concrete frame beam so that long bolts can pass through the reinforced concrete frame beam.

[0009] Furthermore, the bonding material is epoxy resin glue.

[0010] Furthermore, the node plate is an integrated perforated steel plate.

[0011] Furthermore, the channel cover plate is cut from channel steel.

[0012] Compared with the prior art, the present invention has the following beneficial effects:

[0013] 1. The node plate of the present invention has two degrees of freedom of movement under the design of the sliding mechanism, that is, it slides back and forth along the length direction of the reinforced concrete frame beam or along the length direction of the reinforced concrete frame column, thereby releasing the tangential force transmitted by the anti-buckling support structure, which can avoid the opening and closing effect at the connection between the node plate and the reinforced concrete frame beam or the reinforced concrete frame column. The anti-buckling support structure can give full play to its energy dissipation effect, increase the seismic performance, service life and main structure safety of the existing concrete frame structure.

[0014] 2. The design of the outer iron sheet in the present invention increases the rigidity of the reinforced concrete frame beam from two aspects. First, the overall rigidity of the reinforced concrete frame beam will decrease after the hole is opened. When the long stud moves back and forth with the slot cover plate, the collision between the long stud and the slot of the reinforced concrete frame beam is likely to cause the concrete to break. The outer iron sheet can play a limiting role to avoid the above situation, thereby increasing the rigidity of the reinforced concrete frame beam. Second, the outer iron sheet increases the cross-sectional area of ​​the reinforced concrete frame beam, thereby increasing the rigidity of the reinforced concrete frame beam. The increase in the rigidity of the reinforced concrete frame beam increases its bearing capacity and seismic performance.

[0015] 3. The present invention is applied to the existing reinforced concrete frame structure. During construction, it is only necessary to drill holes in the beams and columns, and assemble the anti-buckling support nodes and anti-buckling support structures prefabricated in the factory through bolts. The entire anti-buckling support node has the advantages of convenient construction, easy control of construction quality and improved construction efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings are incorporated as part of this application and are used to provide a further understanding of the present invention.

[0017] Figure 1 The invention discloses an anti-buckling brace node for reinforcing an existing concrete frame structure.

[0018] Figure 2 It is a side view of the present invention.

[0019] Figure 3 for Figure 2 Cross-sectional view at CC.

[0020] Description of reference numerals:

[0021] 1-Node plate;

[0022] 2-sliding mechanism; 21-outer iron sheet, 22-groove cover plate, 23-long bolt, 24-roller shaft;

[0023] 3- Buckling-restrained bracing structure; 4- Reinforced concrete frame beam; 5- Reinforced concrete frame column. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. The following embodiments are used to illustrate the present invention but are not used to limit the scope of the present invention.

[0025] Figure 1 The embodiment of the present invention shows an anti-buckling brace node for strengthening an existing concrete frame structure. Figure 1 It can be seen that the buckling-resistance support node of this embodiment includes a node plate 1 and a sliding mechanism 2 for releasing the tangential force on the node plate 1. The node plate 1 is arranged at the angle between the reinforced concrete frame beam 4 and the reinforced concrete frame column 5. The node plate 1 is provided with a left flange and a lower flange. There are two sliding mechanisms 2. The lower flange of the node plate 1 is connected to the reinforced concrete frame beam 4 via one of the sliding mechanisms 2 and can move along the length direction of the reinforced concrete frame beam 4. The left flange of the node plate 1 is connected to the reinforced concrete frame column 5 via another sliding mechanism 2 and can move along the length direction of the reinforced concrete frame column 5. That is to say, the node plate 1 of this embodiment has two degrees of freedom of movement under the design of the sliding mechanism 2. The buckling-resistance support structure 3 is connected to the node plate 1 and can absorb seismic energy through its own tensile and compressive deformation during an earthquake to prevent the reinforced concrete frame beam 4 and the reinforced concrete frame column 5 from being damaged by the earthquake. When the anti-buckling support structure 3 undergoes tensile or compressive deformation due to force, it will also transmit the force it receives to the node plate 1 and the sliding mechanism 2. The force can be decomposed into normal force and tangential force (tangential force is the force acting along the length direction of the reinforced concrete frame beam 4 or the force acting along the length direction of the reinforced concrete frame column 5, and normal force is the force perpendicular to the length direction of the reinforced concrete frame beam 4 or the force perpendicular to the length direction of the reinforced concrete frame column 5). The two sliding mechanisms 2 cause the node plate 1 to slide back and forth with the reinforced concrete frame beam 4 or the reinforced concrete frame column 5, thereby releasing the tangential force transmitted by the anti-buckling support structure 3, that is, the two degrees of freedom of the node plate 1 can avoid the opening and closing effect at the connection between it and the reinforced concrete frame beam 4 or the reinforced concrete frame column 5. The anti-buckling support structure 3 can give full play to its energy dissipation function, increase the seismic performance, service life and main structure safety of the existing concrete frame structure.

[0026] Depend on Figure 1 It can be seen that the two sliding mechanisms 2 of this embodiment have the same structure, and the structures of the reinforced concrete frame beam 4 and the reinforced concrete frame column 5 are also basically the same, except that the installation directions are different, that is, the connection method of the node plate 1 and the reinforced concrete frame beam 4 and the reinforced concrete frame column 5 is the same, so this embodiment takes the node plate 1 and the reinforced concrete frame beam 4 as an example for explanation. Figure 1Each sliding mechanism 2 of the present embodiment includes an outer iron sheet 21, a grooved cover plate 22, a long bolt 23 and a roller 24. The outer iron sheet 21 is wrapped around the reinforced concrete frame beam 4 and connected to the reinforced concrete frame beam 4 through a bonding material, and the bonding material can be epoxy resin glue; a plurality of rollers 24 are provided and evenly divided into two groups, and the two groups of rollers 24 are respectively arranged on the upper and lower sides of the reinforced concrete frame beam 4; two grooved cover plates 22 are provided, and the two grooved cover plates 22 are relatively arranged on the upper and lower sides of the reinforced concrete frame beam 4 (if it is a reinforced concrete frame column 5, it is the left and right sides), and clamp the two groups of rollers 24; the reinforced concrete frame The frame beam 4 is provided with a plurality of slots penetrating the upper and lower surfaces at positions near the angle, the outer iron sheet 21 is provided with a plurality of through holes arranged relatively to each other, and each slot-shaped cover plate 22 is provided with a plurality of through holes, and the through holes on the slot-shaped cover plate 22 and the through holes on the outer iron sheet 21 correspond one to one with the slots on the reinforced concrete frame beam 4 and are penetrated and connected by long bolts 23 to realize the connection between the slot-shaped cover plate 22 and the reinforced concrete frame beam 4 and the outer iron sheet 21 and to realize the maintenance of the position of the roller shaft 24, wherein the aperture of the slot hole and the through hole on the outer iron sheet 21 is larger than the outer diameter of the stud in the long bolt 23, so that the slot-shaped cover plate 22 can move in the horizontal direction relative to the reinforced concrete frame beam 4. The lower flange of the node plate 1 is welded to the groove cover plate 22 on the upper side of the reinforced concrete frame beam 4. When the node plate 1 is subjected to a tangential force along the length direction of the reinforced concrete frame beam 4, the node plate 1 drives the groove cover plate 22 to move along the length direction of the reinforced concrete frame beam 4. Since the roller shaft 24 is squeezed by the groove cover plate 22 and the reinforced concrete frame beam 4, the roller shaft 24 is subjected to friction during the movement of the groove cover plate 22, and the roller shaft 24 rolls back and forth along the length direction of the reinforced concrete frame beam 4 to release the tangential force applied to the node plate 1.

[0027] It can be seen that in this embodiment, the tangential force on the node plate 1 is released by the cooperation between the groove cover plate 22, the roller 24 and the reinforced concrete frame beam 4, so as to avoid the opening and closing effect at the connection between the node plate 1 and the reinforced concrete frame beam 4 or the reinforced concrete frame column 5. The design of the outer iron sheet 21 in this embodiment increases the rigidity of the reinforced concrete frame beam 4 from two aspects. First, the overall rigidity of the reinforced concrete frame beam 4 will decrease after the hole is opened. In the process of the long stud moving back and forth with the groove cover plate 22, the collision between the long stud and the groove hole of the reinforced concrete frame beam 4 is easy to break the concrete. The outer iron sheet 21 can play a limiting role to avoid the above situation, thereby increasing the rigidity of the reinforced concrete frame beam 4. Second, the outer iron sheet 21 increases the cross-sectional area of ​​the reinforced concrete frame beam 4, thereby increasing the rigidity of the reinforced concrete frame beam 4. The increase in the rigidity of the reinforced concrete frame beam 4 increases its bearing capacity and seismic performance. In addition, since this embodiment is applied to the existing reinforced concrete frame structure, the buckling-resistance support node only needs to punch holes in the beams and columns during construction, and the buckling-resistance support node and buckling-resistance support structure 3 prefabricated in the factory are assembled by bolts, and the outer iron sheet 21 can be wrapped on the reinforced concrete frame beam 4 with an iron plate, and then welded into a cylindrical shape to achieve the fixation of the outer iron sheet 21 and the reinforced concrete frame beam 4. Therefore, the entire buckling-resistance support node has the advantages of convenient construction, easy control of construction quality and improved construction efficiency.

[0028] Among them, the reinforced concrete frame beam 4 is formed by pouring concrete into the beam reinforcement cage, which is composed of transverse force-bearing steel bars and beam stirrups, and the beam reinforcement cage can increase the rigidity of the reinforced concrete frame beam 4. The reinforced concrete frame column 5 is formed by pouring concrete into the column reinforcement cage, which is composed of longitudinal force-bearing steel bars and column stirrups, and the column reinforcement cage can increase the rigidity of the reinforced concrete frame column 5. It should also be noted that the angle between the reinforced concrete frame beam 4 and the reinforced concrete frame column 5 in this embodiment should be 90 degrees, so that the node plate 1 will not be affected in its horizontal and vertical movement due to the different setting directions of the two sliding mechanisms 2.

[0029] The node plate 1, the groove cover plate 22 and the outer iron sheet 21 in this embodiment should be made of Q345 or above steel to ensure the strength of the buckling-resistance support node. The node plate 1 can be made of an integrated perforated steel plate, which has the characteristics of high bearing capacity, large shear stiffness and small slip. The groove cover plate 22 can be welded into a groove shape by steel plates, or directly cut from channel steel. The roller shaft 24 should be made of Q345 or above steel to ensure the stiffness of the roller shaft 24 and avoid the normal force transmitted from the node plate 1 to the roller shaft 24, which will cause the roller shaft 24 to be unable to deform and fail to function during subsequent use due to the inability to roll.

[0030] The embodiments described above are merely descriptions of preferred implementation modes of the present invention and are not intended to limit the scope of the present invention. Without departing from the concept of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should fall within the scope of protection determined by the claims of the present invention.

Claims

1. A buckling-restrained brace node for reinforcing an existing concrete frame structure, comprising a node plate for connecting a buckling-restrained brace structure, characterized in that: It also includes a sliding mechanism for releasing the tangential force on the node plate. There are two sliding mechanisms. The lower flange of the node plate is connected to the reinforced concrete frame beam via one of the sliding mechanisms, and the left flange of the node plate is connected to the reinforced concrete frame column via the other sliding mechanism. When the node plate is subjected to the tangential force, the two sliding mechanisms can make the node plate move along the length direction of the reinforced concrete frame beam or along the length direction of the reinforced concrete frame column to release the tangential force transmitted by the anti-buckling support structure.

2. The buckling-resistance brace node for reinforcing an existing concrete frame structure according to claim 1, characterized in that: Each sliding mechanism includes a groove cover plate and a roller shaft. There are multiple roller shafts and they are evenly divided into two groups. The two groups of roller shafts are respectively arranged on the upper and lower sides of the reinforced concrete frame beam. There are two groove cover plates. The two groove cover plates are relatively arranged on the upper and lower sides of the reinforced concrete frame beam and clamp the two groups of roller shafts. The reinforced concrete frame beam is provided with a plurality of groove holes penetrating the upper and lower surfaces. Each groove cover plate is provided with a plurality of through holes. The through holes on the groove cover plate correspond to the groove holes on the reinforced concrete frame beam one by one and are connected by long bolts. The diameter of the groove holes is larger than the outer diameter of the studs in the long bolts, so that the groove cover plate can move in the horizontal direction of the reinforced concrete frame beam; the lower flange of the node plate is connected to the groove cover plate on the upper side of the reinforced concrete frame beam. When the node plate is subjected to tangential force, the groove cover plate moves with the node plate, and the roller shaft rolls along the length direction of the reinforced concrete frame beam to release the tangential force on the node plate.

3. The buckling-resistance brace node for reinforcing an existing concrete frame structure according to claim 2, characterized in that: Each sliding mechanism also includes an outer iron sheet, which is wrapped around the reinforced concrete frame beam and connected to the reinforced concrete frame beam through an adhesive material. Through holes are opened on the outer iron sheet at positions corresponding to the slots of the reinforced concrete frame beam so that long bolts can pass through the reinforced concrete frame beam.

4. The buckling-resistance brace node for reinforcing an existing concrete frame structure according to claim 3, characterized in that: The bonding material is epoxy resin glue.

5. The buckling-resistance brace node for reinforcing an existing concrete frame structure according to claim 2, characterized in that: The node plate is an integrated perforated steel plate.

6. The buckling-resistance brace node for reinforcing an existing concrete frame structure according to claim 2, characterized in that: The channel cover is cut from channel steel.

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