Rectangular section RC column-U-shaped steel reinforced RC beam connection joint reinforcing structure and reinforcing method
By setting up an adhesive anchoring area at the connection node between the RC column and the U-shaped steel reinforced RC beam, using channel steel and angle steel to form a sleeve and shoot incident nails, the problem of inconvenience in node reinforcement in the prior art is solved, and the nodes are realized Efficient reinforcement and load capacity improvement.
Patent Information
- Application Number
- CN202411944256.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-27
- Publication Date
- 2025-02-14
AI Technical Summary
The prior art is difficult to effectively reinforce the connecting nodes between rectangular cross-section RC columns and U-shaped steel reinforced RC beams, resulting in the nodes being easily damaged under the action of strong earthquakes, and the traditional reinforcement methods are not convenient for use in combination.
By setting an adhesive anchoring zone at the connection node of the RC column and the U-shaped steel reinforced RC beam, weld the sleeve using channel steel and angle steel, and shooting nails into the channel steel reserved holes to reinforce the node.
The rapid reinforcement of beam and column nodes is achieved, the bearing capacity and ductility of the nodes are improved, and the durability is good. There is no need to implant anchor bolts, and the size and weight of the components are changed little.
Smart Images
Figure CN119434697A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of civil engineering reinforcement, and in particular to a rectangular cross-section RC column-U-shaped steel reinforced RC beam connection node reinforcement structure and a reinforcement method. Background Art
[0002] After experiencing large-scale civil engineering facility construction, my country's infrastructure construction has now entered a new stage with equal emphasis on new construction and reinforcement and renovation. At present, there are a large number of reinforced concrete structures in my country that are in the late design service life. Due to the degradation of material properties, natural disasters such as earthquakes, and erosion by the external environment, these reinforced concrete structures or components have varying degrees of damage and deterioration of their bearing performance. In addition, due to the update of design specifications, changes in building use functions, or design and construction defects, there are also many reinforced concrete structures or components that urgently need to improve their bearing capacity.
[0003] The U-shaped steel reinforced RC beam technology is developed on the basis of the U-shaped steel-concrete composite beam theory. This new reinforcement technology can quickly and significantly improve the bearing capacity and deformation capacity of RC beams, and has broad application prospects. However, the linear stiffness ratio between the RC beam and the RC column after U-shaped steel reinforcement changes, which will cause the migration of plastic hinges, and then affect the mechanical performance of the beam-column node. A large number of historical earthquake damages have shown that under strong earthquakes, beam-column nodes are mostly manifested as node domain shear failures, rather than the desired beam end plastic hinge failure mode. Once the node is damaged, it means that the connected beams and columns will fail, and it is difficult to repair the node after the node is damaged. Therefore, it is urgent to use reinforcement methods to reasonably reinforce the connection nodes of RC column-U-shaped steel reinforced RC beams to form a node reinforcement system that is compatible with the U-shaped steel reinforced RC beam technology.
[0004] Traditional beam-column node reinforcement methods include increasing the cross-section method, carbon fiber cloth reinforcement method, and steel plate bonding method. These methods can improve the stress performance of the node to a certain extent, but there are also some shortcomings. The increasing cross-section method involves more wet work, a long construction period, and a large change in the cross-sectional size and deadweight of the component; carbon fiber cloth reinforcement will lead to reduced ductility of the component and poor durability, and the improvement of the node bearing capacity is limited; in order to ensure that the steel plate and the frame structure are firmly bonded, ordinary steel bonding reinforcement requires the implantation of a certain number of anchor bolts in addition to applying building structural adhesive, and the steel bars in the node area are densely arranged, making construction inconvenient. More importantly, the above node reinforcement methods cannot be used well with U-shaped steel reinforced RC beam technology. Summary of the invention
[0005] Based on this, the purpose of the present invention is to provide a rectangular cross-section RC column-U-shaped steel reinforced RC beam connection node reinforcement structure and reinforcement method, which can achieve rapid reinforcement of the node while minimizing the change in component size and deadweight, while improving the bearing capacity and ductility of the node, and has good durability, does not require the implantation of anchor bolts, and causes little damage to the beam-column node.
[0006] In a first aspect, the present invention provides a rectangular cross-section RC column-U-shaped steel reinforced RC beam connection node reinforcement structure, wherein a bonding anchoring area is provided at the connection node between the RC column and the U-shaped steel reinforced RC beam, wherein the bonding anchoring area is bonded with two symmetrically arranged channel steels by means of a building structural adhesive, wherein the flanges of the channel steels are provided with notches matching the cross-sectional dimensions of the U-shaped steel reinforced RC beam, and the two channel steels are welded at the butt joint to form a sleeve; Each of the channel steels is provided with a plurality of reserved holes, each of the reserved holes contains a nail connected to the RC column; At the ends of the U-shaped steel reinforced RC beams on both sides of the connection node, four angle steels are respectively used to connect the U-shaped steel on the U-shaped steel reinforced RC beam with the sleeve by surrounding welding to form a beam-column node reinforcement structure.
[0007] Preferably, the channel steel is formed by cold bending a steel plate or by welding three steel plates; The thickness of the steel plate used for the channel steel is not less than the thickness of the steel plate used for the U-shaped steel; The net distance of the flange of the channel steel is 2-4 mm greater than the cross-sectional width of the RC column, the web width is not less than the sum of the cross-sectional height and the cross-sectional width of the U-shaped steel reinforced RC beam, and the flange width is equal to half of the cross-sectional height of the RC column.
[0008] Preferably, the height of the bonding anchoring area is equal to the web width of the channel steel.
[0009] Preferably, the thickness of the applied building structural adhesive is 1-2 mm.
[0010] Preferably, the nails are made of carbide nails with a diameter of 2.8-3.8 mm and a length of 20-30 mm.
[0011] Preferably, the angle steel is an equal-leg angle steel, and its thickness is the same as that of the channel steel, and its length matches the cross-sectional size of the U-shaped steel reinforced RC beam.
[0012] In a second aspect, the present invention provides a method for reinforcing a connection node of a rectangular cross-section RC column and a U-shaped steel reinforced RC beam, which is implemented by the above-mentioned rectangular cross-section RC column and U-shaped steel reinforced RC beam connection node reinforcement structure, and comprises the following steps: Step S11, determining the bonding anchoring area at the beam-column node connection of the RC column and the U-shaped steel reinforced RC beam, and grinding the four side surfaces of the RC column in the bonding anchoring area; Step S12, applying 1-2 mm thick building structural adhesive to the four side positions of the polished RC column to form a bonding anchoring area, and symmetrically installing the two prepared channel steels in the bonding anchoring area in a manner of opening toward the U-shaped steel reinforced RC beam, and closely fitting with the bonding anchoring area, and at the same time, fitting the flanges of the two channel steels together to form a butt joint; Step S13, after the building structural adhesive is dried, welding is performed at the butt joint of the two channel steels to form an integral sleeve, and nails are driven into each reserved hole of the channel steel to fix the sleeve in the bonding anchoring area; Step S14, at the ends of the U-shaped steel reinforced RC beams on both sides of the connection node, four angle steels are respectively used to connect the U-shaped steel and the sleeve on the U-shaped steel reinforced RC beam by surrounding welding to form a beam-column node reinforcement structure.
[0013] Preferably, the seismic shear bearing capacity of the beam-column node reinforcement structure is: In the formula, is the seismic shear capacity of the node; is the contribution of concrete to the shear bearing capacity of the node area, which is determined by the compressive strength of the concrete diagonal strut; The shear force borne by the stirrups in the node area is calculated according to the shear bearing capacity of the stirrups at the nodes of ordinary reinforced concrete beams and columns; The shear force borne by the welded steel sleeve; is the seismic adjustment coefficient of bearing capacity, which is determined according to Article 11.1.6 of Code for Design of Concrete Structures (GB 50010-2010); is the constraint influence coefficient of the orthogonal beam on the node; is the design value of the axial tensile strength of concrete; It is the effective verification width of the cross section in the core area of the frame node; The cross-sectional height of the core area of the frame node, which can be taken as the cross-sectional height of the column in the verification direction h c ; Nis the design value of the axial pressure at the bottom of the column on the node corresponding to the design value of the combined seismic shear force. For the first-level seismic grade frame with a design intensity of 9 degrees, the beneficial effect of the axial pressure is not considered; To verify the cross-sectional width of the direction column; is the design value of the tensile strength of the stirrups, generally taken as , but when When ; The total cross-sectional area of each leg of stirrups in the same cross-sectional verification direction within the effective verification width of the core area; is the effective height of the frame beam section; It is the distance from the combined force point of the compressive reinforcement in the beam to the near side of the section; s is the stirrup spacing in the core area of the node; The yield strength of the steel plate used for the sleeve; The thickness of the steel plate used for the sleeve.
[0014] Compared with the prior art, the present invention has the following beneficial effects: (1) The present invention is specifically applicable to the reinforcement of the connection node between a rectangular cross-section RC column and a U-shaped steel reinforced RC beam, and can be adapted to the U-shaped steel reinforced RC beam technology. Angle steel is used as a connecting piece, and the U-shaped steel reinforced RC beam is firmly connected to the sleeve by welding to form a beam-column node reinforcement system. The force is clear, and it is convenient for industrialized production, which meets the development needs of building assembly. (2) The present invention has fewer reinforcement components, simple steps, short construction period, no wet work is required, and the beam-column joint can be reinforced by only cutting and welding the sleeve, which can quickly and significantly improve the bearing capacity and ductility of the beam-column joint, and has little effect on the cross-sectional size and deadweight of the component; (3) In addition to applying building structural adhesive to bond and anchor the sleeve to the beam-column node, the present invention also uses nailing to further anchor, which greatly improves the overall working performance between the two and overcomes the problem that the bonded steel plate is easily peeled off at the end. At the same time, compared with bolts, using nailing to further anchor the sleeve will cause much less damage to the reinforced concrete node area, and will not be affected by the dense arrangement of steel bars inside the node area, making the construction more convenient. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Figure 1 A three-dimensional diagram of the connection node reinforcement structure of the rectangular cross-section RC column-U-shaped steel reinforced RC beam in the present invention; Figure 2 It is a front view schematic diagram of the connection node reinforcement structure of the rectangular cross-section RC column-U-shaped steel reinforced RC beam in the present invention; Figure 3 It is a transverse cross-sectional schematic diagram of the reinforcement structure of the connection node of the rectangular cross-section RC column-U-shaped steel reinforced RC beam in the present invention; Figure 4 It is a side elevation schematic diagram of the rectangular cross-section RC column-U-shaped steel reinforced RC beam connection node reinforcement structure in the present invention; Figure 5 It is a front schematic diagram, a plane development diagram and a side schematic diagram of the channel steel with a notch on the flange of the present invention.
[0016] Description of main component symbols: 1- sleeve; 2- U-shaped steel reinforced RC beam; 3- RC column; 4- angle steel; 5- nail; 6- bonding anchorage area; 7- channel steel.
[0017] The following specific implementation manner will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION
[0018] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only examples, and those skilled in the art may think of other obvious variations.
[0019] See also Figures 1 to 5 In one embodiment of the present invention, a rectangular cross-section RC column-U-shaped steel reinforced RC beam connection node reinforcement structure is provided, wherein a bonding anchoring area 6 is provided at the connection node between the RC column 3 and the U-shaped steel reinforced RC beam 2, wherein the bonding anchoring area 6 is bonded with two symmetrically arranged channel steels 7 by means of a building structural adhesive, wherein the flange of the channel steel 7 is provided with a notch matching the cross-sectional size of the U-shaped steel reinforced RC beam 2, and the two channel steels 7 are welded at the butt joint to form a sleeve 1; Each of the channel steels 7 is provided with a plurality of reserved holes, each of which contains a nail 5 connected to the RC column 3; At the ends of the U-shaped steel reinforced RC beam 2 on both sides of the connection node, four angle steels 4 are respectively used to connect the U-shaped steel on the U-shaped steel reinforced RC beam 2 with the sleeve 1 by surrounding welding to form a beam-column node reinforcement structure.
[0020] It should be noted that the channel steel 7 in the present invention is formed by cold bending a steel plate or welding three steel plates, and the thickness of the steel plate used is not less than that of the U-shaped steel ( Figure 2 The pink structure in the figure) has a steel plate thickness and a channel steel flange clearance of 7 s f Width of RC column 3 sections b c2~4mm larger; web width b w Not less than the cross-sectional height of the U-shaped steel reinforced RC beam 2 h b With section width b b Sum of flange width b f Equal to the RC column section height h c Half of the length. After cutting, notches matching the cross-sectional dimensions of the U-shaped steel reinforced RC beam 2 are left on the flanges of the channel steel 7. At the same time, multiple nail holes are reserved on the flanges and webs. The hole diameter is slightly larger than the nail diameter to ensure smooth driving of the nails. The width of the notch at the flange is b h RC beam with U-shaped steel reinforcement 2 sections height h b Equal, notch height h h Equal to the width of the U-shaped steel reinforced RC beam 2 b b Half of the flange length remaining on both sides of the notch l f 'Not less than the width of the U-shaped steel reinforced RC beam 2 b b half.
[0021] The sleeve 1 is formed by first bonding two identical channel steels 7 to the bonding anchoring area 6 and then welding them at the joint. Before bonding the channel steel 7, the four sides of the RC column 3 within the bonding anchoring area 6 need to be polished and processed, including cleaning the surface and repairing the missing concrete. The height of the bonding anchoring area 6 is equal to the width of the web of the channel steel 7. b w equal.
[0022] The thickness of the building structure adhesive applied to the bonding anchoring area 6 is 1-2 mm, and the driven nails 5 are hard alloy nails with a diameter of 2.8-3.8 mm and a length of 20-30 mm.
[0023] The angle steel 4 is an equal-leg angle steel with the same thickness as the channel steel 7, including 4 lengths and the same width as the cross-section of the U-shaped steel reinforced RC beam 2. b b Same angle steel, and 4 lengths with U-shaped steel reinforced RC beam 2 sections height h b The same angle steel is used; the U-shaped steel on the U-shaped steel reinforced RC beam 2 is connected to the sleeve 1 through the angle steel 4 to form a beam-column node reinforcement system.
[0024] In a second aspect, the present invention provides a method for reinforcing a connection node of a rectangular cross-section RC column and a U-shaped steel reinforced RC beam, which is implemented by the above-mentioned rectangular cross-section RC column and U-shaped steel reinforced RC beam connection node reinforcement structure, and comprises the following steps: Step S11, determining the bonding anchoring area at the beam-column node connection of the RC column and the U-shaped steel reinforced RC beam, and grinding the four side surfaces of the RC column in the bonding anchoring area; Step S12, applying 1-2 mm thick building structural adhesive to the four side positions of the polished RC column to form a bonding anchoring area, symmetrically installing the two prepared channel steels in the bonding anchoring area with their openings facing the U-shaped steel reinforced RC beam, and closely fitting them to the bonding anchoring area, while fitting the flanges of the two channel steels together to form a butt joint; Step S13, after the building structural adhesive is dried, welding is performed at the butt joint of the two channel steels to form an integral sleeve, and nails are driven into each reserved hole of the channel steel to fix the sleeve in the bonding anchoring area; Step S14, at the ends of the U-shaped steel reinforced RC beams on both sides of the connection node, four angle steels are respectively used to connect the U-shaped steel and the sleeve on the U-shaped steel reinforced RC beam by surrounding welding to form a beam-column node reinforcement structure.
[0025] Furthermore, the seismic shear bearing capacity of the connection node of the rectangular cross-section RC column and the U-shaped steel reinforced RC beam after sleeve reinforcement of the present invention is: ; The seismic shear bearing capacity of the connection node between the unreinforced rectangular cross-section RC column and the U-shaped steel reinforced RC beam is: ; In the formula, is the seismic shear capacity of the node; is the contribution of concrete to the shear bearing capacity of the node area, which is determined by the compressive strength of the concrete diagonal strut; The shear force borne by the stirrups in the node area is calculated according to the shear bearing capacity of the stirrups at the nodes of ordinary reinforced concrete beams and columns; The shear force borne by the welded steel sleeve; is the seismic adjustment coefficient of bearing capacity, which is determined according to Article 11.1.6 of Code for Design of Concrete Structures (GB 50010-2010); is the constraint influence coefficient of the orthogonal beam on the node; is the design value of the axial tensile strength of concrete; It is the effective verification width of the cross section in the core area of the frame node; The cross-sectional height of the core area of the frame node, which can be taken as the cross-sectional height of the column in the verification direction h c; N is the design value of the axial pressure at the bottom of the column on the node corresponding to the design value of the combined seismic shear force. For the first-level seismic grade frame with a design intensity of 9 degrees, the beneficial effect of the axial pressure is not considered; To verify the cross-sectional width of the direction column; is the design value of the tensile strength of the stirrups, generally taken as , but when When ; The total cross-sectional area of each leg of stirrups in the same cross-sectional verification direction within the effective verification width of the core area; is the effective height of the frame beam section; It is the distance from the combined force point of the compressive reinforcement in the beam to the near side of the section; s is the stirrup spacing in the core area of the node; The yield strength of the steel plate used for the sleeve; The thickness of the steel plate used for the sleeve.
[0026] It should be noted that the seismic shear bearing capacity of the connection node of the rectangular cross-section RC column-U-shaped steel reinforced RC beam reinforced by the present invention should meet the following conditions: In the formula, is the design value of the axial compressive strength of concrete; is the influence coefficient of concrete strength; the physical meanings of other symbols are the same as above.
[0027] Taking a rectangular cross-section RC column-U-shaped steel reinforced RC beam connection node as an example, the above formula is used to calculate the seismic shear bearing capacity of the node before and after reinforcement, and the reinforcement effect is compared and analyzed.
[0028] (1) Basic parameters , ; Using C40 concrete: , , ; , ; Pick ; The stirrups are made of HRB335 grade steel bars with a diameter of 10mm@50: , (Limb Hoops), s =50mm; , ; The steel plate used for the sleeve is Q345B grade steel plate with a thickness of 8mm: , .
[0029] (2) Calculation of node seismic shear capacity Not reinforced: After reinforcement: Restrictions: (3) Reinforcement effect The seismic shear bearing capacity of the node reinforced by the present invention is increased by 50.2% compared with that before reinforcement.
[0030] It can be seen that the seismic shear bearing capacity of the unreinforced rectangular cross-section RC column-U-shaped steel reinforced RC beam connection node is composed of the shear bearing capacity of the concrete diagonal compression rod and the horizontal stirrup. The seismic shear bearing capacity of the node reinforced by the present invention has an additional shear bearing capacity of the steel sleeve in addition to the above two parts. This can significantly improve the anti-seismic shear bearing capacity of the node. In addition, after reinforcement by the present invention, the sleeve increases the restraint effect on the concrete in the node area and can also delay the development of concrete cracks, thereby improving the shear bearing capacity and ductility of the node to a certain extent.
[0031] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions only describe the principles of the present invention. The present invention may be subject to various changes and improvements without departing from the spirit and scope of the present invention. These changes and improvements fall within the scope of the present invention. The scope of protection claimed by the present invention is defined by the attached claims and their equivalents.
Claims
1. A rectangular cross-section RC column-U-shaped steel reinforced RC beam connection node reinforcement structure, characterized in that: A bonding anchoring area is provided at the connection node between the RC column and the U-shaped steel reinforced RC beam, and the bonding anchoring area is bonded with two symmetrically arranged channel steels by means of building structural adhesive, and the flanges of the channel steels are provided with notches matching the cross-sectional dimensions of the U-shaped steel reinforced RC beam, and the two channel steels are welded at the butt joint to form a sleeve; Each of the channel steels is provided with a plurality of reserved holes, each of the reserved holes contains a nail connected to the RC column; At the ends of the U-shaped steel reinforced RC beam on both sides of the connection node, four angle steels are respectively used to connect the U-shaped steel on the U-shaped steel reinforced RC beam with the sleeve by surrounding welding to form a beam-column node reinforcement structure.
2. The rectangular cross-section RC column-U-shaped steel reinforced RC beam connection node reinforcement structure according to claim 1 is characterized in that: The channel steel is formed by cold bending a steel plate or welding three steel plates; The thickness of the steel plate used for the channel steel is not less than the thickness of the steel plate used for the U-shaped steel; The net distance of the flange of the channel steel is 2-4 mm larger than the cross-sectional width of the RC column, the web width is not less than the sum of the cross-sectional height and the cross-sectional width of the U-shaped steel reinforced RC beam, and the flange width is equal to half of the cross-sectional height of the RC column.
3. The rectangular cross-section RC column-U-shaped steel reinforced RC beam connection node reinforcement structure according to claim 1 is characterized in that: The height of the bonding anchoring area is equal to the web width of the channel steel.
4. The rectangular cross-section RC column-U-shaped steel reinforced RC beam connection node reinforcement structure according to claim 1 is characterized in that: The thickness of the applied structural adhesive is 1~2mm.
5. The rectangular cross-section RC column-U-shaped steel reinforced RC beam connection node reinforcement structure according to claim 1 is characterized in that: The nails are made of carbide nails with a diameter of 2.8-3.8 mm and a length of 20-30 mm.
6. The rectangular cross-section RC column-U-shaped steel reinforced RC beam connection node reinforcement structure according to claim 1 is characterized in that: The angle steel is an equal-leg angle steel, and its thickness is the same as that of the channel steel, and its length matches the cross-sectional size of the U-shaped steel reinforced RC beam.
7. A method for reinforcing a connection node between a rectangular cross-section RC column and a U-shaped steel reinforced RC beam, characterized in that: The method is implemented by adopting the rectangular cross-section RC column-U-shaped steel reinforced RC beam connection node reinforcement structure as described in any one of claims 1 to 6, including the following steps: Step S11, determining the bonding anchoring area at the beam-column node connection of the RC column and the U-shaped steel reinforced RC beam, and grinding the four side surfaces of the RC column in the bonding anchoring area; Step S12, applying 1-2 mm thick building structural adhesive to the four side positions of the polished RC column to form a bonding anchoring area, symmetrically installing the two prepared channel steels in the bonding anchoring area with their openings facing the U-shaped steel reinforced RC beam, and closely fitting them to the bonding anchoring area, while fitting the flanges of the two channel steels together to form a butt joint; Step S13, after the building structural adhesive is dried, welding is performed at the butt joint of the two channel steels to form an integral sleeve, and nails are driven into each reserved hole of the channel steel to further fix the sleeve in the bonding anchoring area; Step S14, at the ends of the U-shaped steel reinforced RC beams on both sides of the connection node, four angle steels are respectively used to connect the U-shaped steel and the sleeve on the U-shaped steel reinforced RC beam by surrounding welding to form a beam-column node reinforcement structure.
8. The method for reinforcing a connection node between a rectangular cross-section RC column and a U-shaped steel reinforced RC beam according to claim 7, characterized in that: The seismic shear bearing capacity of the beam-column joint reinforcement structure is: In the formula, is the seismic shear capacity of the node; is the contribution of concrete to the shear bearing capacity of the node area, which is determined by the compressive strength of the concrete diagonal strut; The shear force borne by the stirrups in the node area is calculated according to the shear bearing capacity of the stirrups at the nodes of ordinary reinforced concrete beams and columns; The shear force borne by the welded steel sleeve; is the seismic adjustment coefficient of bearing capacity, which is taken in accordance with Article 11.1.6 of the Code for Design of Concrete Structures (GB 50010-2010); is the constraint influence coefficient of the orthogonal beam on the node; is the design value of the axial tensile strength of concrete; It is the effective verification width of the cross section in the core area of the frame node; is the cross-sectional height of the core area of the frame node, which can be taken as the column cross-sectional height in the verification direction h c; N is the design value of the axial pressure at the bottom of the column on the node corresponding to the design value of the combined seismic shear force. For the first-level seismic grade frame with a design intensity of 9 degrees, the beneficial effect of the axial pressure is not considered; To verify the cross-sectional width of the direction column; is the design value of the tensile strength of the stirrups, generally taken as , but when When ; The total cross-sectional area of each leg of stirrups in the same cross-sectional verification direction within the effective verification width of the core area; is the effective height of the frame beam section; It is the distance from the combined force point of the compressive reinforcement in the beam to the near side of the section; s is the stirrup spacing in the core area of the node; The yield strength of the steel plate used for the sleeve; The thickness of the steel plate used for the sleeve.