Strong beam and weak column type transfer beam and steel reinforced concrete column connecting joint and design method

Abstract

The invention discloses a strong-beam and weak-column type transfer beam and steel reinforced concrete column connecting joint and a design method, belongs to the technical field of building structure engineering, and solves the problem that existing transfer beam and column joints are difficult to construct, and concrete pouring quality is easy to cause. The connecting joint comprises a reinforced concrete column and a reinforced concrete beam, first profile steel is arranged in the reinforced concrete column in the axial direction, and the connecting joint is characterized in that the upper end of the first profile steel extends into the reinforced concrete beam, a plurality of column longitudinal bars are arranged in the reinforced concrete column in the axial direction, and the first profile steel is arranged in the column longitudinal bars in the axial direction. A continuous composite rectangular spiral hoop connected with the column longitudinal bar is arranged on the column longitudinal bar, and a connecting plate is arranged on the outer side of the profile steel at the connecting joint of the reinforced concrete column and the reinforced concrete beam. According to the strong-beam and weak-column type transfer beam and steel reinforced concrete column connecting joint and the design method, construction of the transfer beam and steel reinforced concrete column joint is facilitated while the bearing capacity is met, and therefore the concrete pouring quality of the joint is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of building structure engineering, in particular to a connection node and a design method of a weak-column-type conversion beam and a steel-concrete column. Background Art

[0002] With the advancement of social economy, building functions are becoming increasingly complex, and the weight supported by transfer beams can sometimes be enormous. For example, some existing subway depots with fully framed shear wall structures have reached heights of 150 meters. Transfer beams must support the weight of over 40 stories above them. Due to the functional requirements of the depot, the span also reaches approximately 18 meters. This results in a large cross-section for the transfer beams, resulting in high bending capacity, making the "strong column, weak beam" design impossible.

[0003] Steel-concrete structures have high bearing capacity and good seismic ductility, but the construction of beam and column nodes is complicated, which often gives construction units a headache. For steel-concrete structures with high bearing capacity of transfer beams, which cannot achieve "strong columns and weak beams", blindly increasing the longitudinal reinforcement of the transfer columns and increasing the width of the steel flanges will not only still fail to achieve "strong columns and weak beams", but will also lead to excessive longitudinal reinforcement in the columns and excessive width of the steel flanges in the columns, making the construction of transfer beam and column nodes difficult and easily causing concrete pouring quality problems. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to address the above-mentioned deficiencies in the prior art and provide a connection node and design method for a strong-beam-weak-column type transfer beam and a steel-concrete column. While meeting the bearing capacity, it facilitates the construction of the transfer beam and steel-concrete column node, thereby ensuring the quality of the node concrete pouring, and has the characteristics of ease of use and strong practicality.

[0005] The technical solution adopted by the present invention is: a connection node between a strong-beam-weak-column type conversion beam and a steel-concrete column, including a reinforced concrete column and a reinforced concrete beam, a first steel section is axially arranged in the reinforced concrete column, and is characterized in that the upper end of the first steel section extends into the reinforced concrete beam, a plurality of axially arranged column longitudinal bars are provided in the reinforced concrete column, a continuous composite rectangular spiral hoop connected to the column longitudinal bars is provided on the column longitudinal bars, a connecting plate is provided on the outside of the steel section at the connection node between the reinforced concrete column and the reinforced concrete beam, beam longitudinal bars are provided in the reinforced concrete beam, the beam longitudinal bars are connected to the first steel section through the connecting plate, and composite stirrups are provided on the beam longitudinal bars.

[0006] As a further improvement, a second steel section is provided in the axial direction of the reinforced concrete beam, and bolts are provided between the second steel section and the longitudinal reinforcement of the beam.

[0007] Furthermore, weldable mechanical connection sleeves are provided on the outer sides of the steel sections at the connection nodes between the reinforced concrete columns and the reinforced concrete beams.

[0008] Furthermore, stiffening ribs are provided on the inner sides of the first and second steel sections at the connection nodes between the reinforced concrete columns and the reinforced concrete beams.

[0009] Furthermore, composite stirrups are provided on the column longitudinal reinforcement in the reinforced concrete beam.

[0010] Furthermore, a steel mesh is provided at the upper end of the reinforced concrete column, and the upper end of the steel mesh extends into the reinforced concrete beam.

[0011] Furthermore, the continuous composite rectangular spiral hoop includes an outer spiral hoop, an inner spiral hoop and a single-leg hoop, the outer spiral hoop is arranged on the outer side of the column longitudinal reinforcement, the inner spiral hoop is arranged on the inner side of the column longitudinal reinforcement, and the single-leg hoop is arranged on two column longitudinal reinforcements at right angles.

[0012] Furthermore, a mortar layer is provided on the surface of the reinforced concrete column.

[0013] Furthermore, the cross section of the first steel section is a cross-shaped structure, and flange plates are provided on the ribs of the first steel section.

[0014] The design method of the connection node between the strong beam and weak column type transfer beam and the steel concrete column includes the following steps:

[0015] (1) Calculate the longitudinal reinforcement and steel cross-section of steel-reinforced concrete columns according to the current specifications, but do not adjust the column top bending moment value for the seismic action combination according to relevant regulations. If the column longitudinal reinforcement and steel cross-section obtained are already convenient for the construction of transfer beams and column nodes and for the placement of continuous composite rectangular spiral hoops, the column longitudinal reinforcement and steel cross-section are taken as above and the following step 2 is skipped.

[0016] (2) The longitudinal reinforcement and steel section of the steel-concrete column are calculated according to the provisions of the current specifications, but the column top bending moment value of the seismic action combination is not adjusted according to the relevant provisions. The column longitudinal reinforcement and steel section obtained are still too many or too large, which is not convenient for the construction of the conversion beam and column node and the placement of the continuous composite rectangular spiral hoop. The column longitudinal reinforcement and steel section are calculated according to the standard value of the effect of the load and seismic action combination, that is, formula (1), and the column top bending moment value of the seismic action combination is not adjusted according to the relevant provisions;

[0017] S GE +γ Eh S Ehk +γ Ev S Evk +ψ w γ w S wk ≤R(1)

[0018] Where: S GE is the effect of the representative value of gravity load; S Ehk 、SEvk Divided into the effects of horizontal and vertical earthquake action standard values; S wk is the effect of the standard value of wind load; ψ w is the combined value coefficient of wind load; γ Eh , γ Ev , γ w are the partial factors of horizontal earthquake action, vertical earthquake action and wind load respectively; R is the design value of the resistance of structural components; γ Eh , γ Ev , γ w , ψ w All values ​​are taken according to the current specifications, but when greater than 1.0, they are taken as 1.0;

[0019] (3) The stirrups of the steel-concrete columns in the transfer layer are calculated according to the current specifications. The stirrups in the columns are continuous composite rectangular spiral stirrups with excellent mechanical properties.

[0020] (4) For stirrups in reinforced concrete beam and reinforced concrete column nodes: When the reinforced concrete beam is not provided with a second steel section, a continuous composite rectangular spiral stirrup is used; when the reinforced concrete beam is provided with a second steel section, the usual composite stirrup is used due to the obstruction of the steel section in the beam.

[0021] Beneficial effects

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] 1. Compared with the existing general transfer beam-steel concrete column connection node, the ductility of the concrete transfer column is increased by setting steel sections, continuous composite rectangular spiral hoops, and surface wire mesh. While meeting the bearing capacity, the number of longitudinal reinforcement in the column and the width of the steel flange are reduced, which facilitates the construction of the transfer beam-steel concrete column node and ensures the quality of the node concrete pouring.

[0024] 2. Compared with the existing general steel-concrete columns, the installation of wire mesh can prevent the concrete soil from falling off prematurely during an earthquake, thereby enhancing the ductility and energy dissipation capacity of the column top.

[0025] 3. Compared with the existing general reinforced concrete columns, by setting steel sections and composite rectangular spiral hoops in the columns, the steel sections can reduce the axial compression ratio of the concrete columns, and the continuous composite rectangular spiral hoops reduce the number of stirrup joints, thereby increasing the bearing capacity, ductility and energy dissipation capacity of the columns. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of the main structure of Example 1 of the present invention;

[0027] Figure 2 for Figure 1 The enlarged cross-sectional view at AA in the middle;

[0028] Figure 3 for Figure 1 A schematic diagram of the cross section at the middle BB;

[0029] Figure 4 This is a schematic diagram of the main structure of Example 2 of the present invention;

[0030] Figure 5 for Figure 4 A magnified schematic cross-sectional view of the CC in the middle;

[0031] Figure 6 This is an enlarged schematic diagram of the outer spiral hoop structure of the present invention;

[0032] Figure 7 It is an enlarged schematic diagram of the inner spiral hoop structure in the present invention;

[0033] Figure 8 It is an enlarged schematic diagram of the steel wire mesh facade in the present invention.

[0034] Among them: 1-reinforced concrete column, 2-first steel section, 3-reinforced concrete beam, 4-column longitudinal reinforcement, 5-continuous composite rectangular spiral stirrup, 6-wire mesh, 7-beam longitudinal reinforcement, 8-stiffening rib, 9-connecting plate, 10-mortar layer, 11-single-leg stirrup, 12-second steel section, 13-composite stirrup, 14-weldable mechanical connection sleeve, 15-stud, 51-external spiral stirrup, 52-inner spiral stirrup. DETAILED DESCRIPTION

[0035] The present invention will be further described below with reference to the specific embodiments in the accompanying drawings.

[0036] Example 1

[0037] See Figure 1-3 As shown, the connection node of the strong beam weak column type conversion beam and the steel-concrete column of the present invention includes a reinforced concrete column 1 and a reinforced concrete beam 3. A first steel section 2 is axially provided in the reinforced concrete column 1, and is characterized in that the upper end of the first steel section 2 extends into the reinforced concrete beam 3, a plurality of axially arranged column longitudinal bars 4 are provided in the reinforced concrete column 1, and a continuous composite rectangular spiral hoop 5 connected thereto is provided on the column longitudinal bars 4, a connecting plate 9 is provided on the outer side of the first steel section 2 at the connection node between the reinforced concrete column 1 and the reinforced concrete beam 3, a beam longitudinal bar 7 is provided in the reinforced concrete beam 3, the beam longitudinal bar 7 is connected to the first steel section 2 through the connecting plate 9, and a composite hoop 13 is provided on the beam longitudinal bar 7.

[0038] In this embodiment, the cross-section of the column longitudinal reinforcement 4 and the first steel 2 of the steel-concrete column is calculated according to the provisions of the current specifications, and the stirrups of the steel-concrete column of the transfer layer are calculated according to the provisions of the current specifications. The ductility of the reinforced concrete column 1 is increased by arranging the first steel 2, the continuous composite rectangular spiral stirrup 5, and the wire mesh 6. While meeting the bearing capacity, the number of longitudinal reinforcements and the width of the steel flange in the column are reduced, which facilitates the construction of the transfer beam-steel concrete column node and ensures the quality of the node concrete pouring. At the same time, it also creates favorable conditions for the use of the continuous composite rectangular spiral stirrup 5 with excellent stress performance in the transfer column; the top of the first steel 2 extends to the bottom of the upper longitudinal reinforcement of the reinforced concrete beam, which facilitates the upper longitudinal reinforcement of the reinforced concrete beam to pass through the node and facilitates construction. By arranging steel and continuous composite rectangular spiral stirrups 4 in the column, the steel can reduce the axial compression ratio of the concrete column, and the continuous composite rectangular spiral stirrups 4 reduce the stirrup joints, thereby increasing the bearing capacity, ductility and energy consumption capacity of the column.

[0039] Example 2

[0040] The difference between this example and Example 1 is that a second steel section 12 is provided axially in the reinforced concrete beam 3, a bolt 15 is provided between the second steel section 12 and the beam longitudinal reinforcement 7, and a weldable mechanical connection sleeve 14 is provided on the outer side of the steel section at the connection node between the reinforced concrete column 1 and the reinforced concrete beam 3. The bearing capacity of the reinforced concrete beam 3 can be effectively increased by the second steel section 12, and the beam longitudinal reinforcement 7 and the column longitudinal reinforcement 4 are connected to the steel section through the weldable mechanical connection sleeve 14 to increase the reliability of the connection. The bolt 15 enhances the structural connectivity, transfers the load, and improves the overall stability.

[0041] Furthermore, stiffening ribs 8 are provided inside the first section steel 2 and the second section steel 12 at the connection node between the reinforced concrete column 1 and the reinforced concrete beam 3. The stiffening ribs 8 prevent local buckling of the section steel and enhance the shear bearing capacity of the node area.

[0042] Furthermore, composite stirrups 13 are provided on the column longitudinal reinforcement 4 in the reinforced concrete beam 3. Due to the obstruction of the steel sections in the beam, the composite stirrups 13 can effectively avoid interference, which is beneficial to construction.

[0043] Furthermore, a steel mesh 6 is provided at the upper end of the reinforced concrete column 1, and the upper end of the steel mesh 6 extends into the reinforced concrete beam 3. The steel mesh 6 is woven from galvanized steel wires. The diameter of the galvanized steel wires is 4mm to 6mm, and the grid spacing is 50mm to 100mm. The steel mesh 6 prevents the concrete from falling off prematurely during an earthquake, and enhances the ductility and energy consumption capacity of the column foot. In order to facilitate concrete pouring, the steel mesh is placed on the surface of the concrete component. The diameter of the steel wire has reserved a corrosion allowance, and a 20mm to 30mm thick mortar layer is applied to the surface of the steel wire for protection.

[0044] Furthermore, the continuous composite rectangular spiral hoop 5 includes an outer spiral hoop 51, an inner spiral hoop 52 and a single-leg hoop 11. The outer spiral hoop 51 is arranged on the outer side of the column longitudinal reinforcement 4, the inner spiral hoop 52 is arranged on the inner side of the column longitudinal reinforcement 4, and the single-leg hoop 11 is arranged on the two column longitudinal reinforcements 4 at right angles. The use of double spiral hoops increases the stability of the structure. The continuous composite rectangular spiral hoop 5 reduces the number of stirrup joints and enhances the bearing capacity, ductility and energy dissipation capacity of the column foot.

[0045] Furthermore, a mortar layer 10 is provided on the surface of the reinforced concrete column 1. The mortar layer 10 is a high-performance composite mortar layer, which is applied under pressure to ensure that there are no bubbles in the high-performance composite mortar and that it is in close contact with the concrete. The mortar layer 10 protects the wire mesh 6 and prevents the wire mesh 6 from oxidizing and rusting.

[0046] Furthermore, the cross-section of the first steel section 2 is a cross-shaped structure, which provides more stability when connecting complex nodes. The ribs of the first steel section 2 are all provided with flange plates, which increase the cross-sectional area of ​​the steel section when subjected to pressure and torque, thereby improving the bearing capacity and stiffness of the steel section, and further increasing the stability and safety of the steel structure.

[0047] The design method of the connection node between the strong beam and weak column type transfer beam and the steel concrete column includes the following steps:

[0048] (1) Calculate the longitudinal reinforcement and steel cross-section of steel-reinforced concrete columns according to the current specifications, but do not adjust the column top bending moment value for the seismic action combination according to relevant regulations. If the column longitudinal reinforcement and steel cross-section obtained are already convenient for the construction of transfer beams and column nodes and for the placement of continuous composite rectangular spiral hoops, the column longitudinal reinforcement and steel cross-section are taken as above and the following step 2 is skipped.

[0049] (2) The longitudinal reinforcement and steel section of the steel-concrete column are calculated according to the provisions of the current specifications, but the column top bending moment value of the seismic action combination is not adjusted according to the relevant provisions. The column longitudinal reinforcement and steel section obtained are still too many or too large, which is not convenient for the construction of the conversion beam and column node and the placement of the continuous composite rectangular spiral hoop. The column longitudinal reinforcement and steel section are calculated according to the standard value of the effect of the load and seismic action combination, that is, formula (1), and the column top bending moment value of the seismic action combination is not adjusted according to the relevant provisions;

[0050] S GE +γ Eh S Ehk +γ Ev S Evk +ψ w γ w S wk ≤R (1)

[0051] Where: S GE is the effect of the representative value of gravity load; S Ehk 、SEvk Divided into the effects of horizontal and vertical earthquake action standard values; S wk is the effect of the standard value of wind load; ψ w is the combined value coefficient of wind load; γ Eh , γ Ev , γ w are the partial factors of horizontal earthquake action, vertical earthquake action and wind load respectively; R is the design value of the resistance of structural components; γ Eh , γ Ev , γ w , ψ w All values ​​are taken according to the current specifications, but when greater than 1.0, they are taken as 1.0;

[0052] (3) The internal stirrups of reinforced concrete columns are calculated according to the current specifications. The internal stirrups of the columns are in the form of continuous composite rectangular spiral stirrups with excellent mechanical properties;

[0053] (4) For stirrups in reinforced concrete beam and reinforced concrete column nodes: When the reinforced concrete beam is not provided with a second steel section, a continuous composite rectangular spiral stirrup is used; when the reinforced concrete beam is provided with a second steel section, the usual composite stirrup is used due to the obstruction of the steel section in the beam.

[0054] In this embodiment, the longitudinal reinforcement of the steel-concrete column, the steel cross-section, and the internal column stirrups are calculated to minimize the steel cross-section and column longitudinal reinforcement. This facilitates the placement of continuous composite rectangular spiral stirrups or reduces the bottom reinforcement of the transfer beam, which cannot pass through the node area due to the obstruction of the column steel flange. During design, the longitudinal reinforcement of the steel-concrete transfer column is calculated based on the combined effects of load and seismic action. However, the design value of the column top bending moment for the combined seismic action is not adjusted according to relevant regulations. This means that the "strong column, weak beam" seismic resistance requirement is not met. Instead, the ductility of the concrete transfer column is increased by installing steel, continuous composite rectangular spiral stirrups, and surface steel mesh. Because this approach requires fewer column longitudinal reinforcements and narrower steel flange widths, it facilitates the construction of the transfer beam-steel-concrete column node and ensures the quality of the node concrete pouring.

[0055] The above is only a preferred embodiment of the present invention. It should be pointed out that for those skilled in the art, several modifications and improvements can be made without departing from the structure of the present invention. These modifications and improvements will not affect the effect of the implementation of the present invention and the practicality of the patent.

Claims

1. A connection node between a strong beam and weak column type conversion beam and a steel-concrete column, comprising a reinforced concrete column (1) and a reinforced concrete beam (3), wherein a first steel section (2) is provided in the axial direction of the reinforced concrete column (1), characterized in that: The upper end of the first steel section (2) extends into the reinforced concrete beam (3); a plurality of axially arranged column longitudinal bars (4) are provided in the reinforced concrete column (1); a continuous composite rectangular spiral hoop (5) connected thereto is provided on the column longitudinal bars (4); a connecting plate (9) is provided on the outside of the first steel section (2) at the connection node between the reinforced concrete column (1) and the reinforced concrete beam (3); beam longitudinal bars (7) are provided in the reinforced concrete beam (3); the beam longitudinal bars (7) are connected to the first steel section (2) via the connecting plate (9); and composite hoop bars (13) are provided on the beam longitudinal bars (7).

2. The connection node between the strong beam and weak column type transfer beam and the steel concrete column according to claim 1 is characterized in that: A second steel section (12) is provided in the axial direction of the reinforced concrete beam (3), and bolts (15) are provided between the second steel section (12) and the beam longitudinal reinforcement (7).

3. The connection node between the strong beam and weak column type transfer beam and the steel concrete column according to claim 2 is characterized in that: The outer sides of the steel sections at the connection nodes between the reinforced concrete column (1) and the reinforced concrete beam (3) are provided with weldable mechanical connection sleeves (14).

4. The connection node between the strong beam and weak column type transfer beam and the steel concrete column according to claim 1 or 2, characterized in that: Stiffening ribs (8) are provided on the inner sides of the first steel section (2) and the second steel section (12) at the connection nodes of the reinforced concrete column (1) and the reinforced concrete beam (3).

5. The connection node between the strong beam and weak column type transfer beam and the steel concrete column according to claim 2 is characterized in that: Composite stirrups (13) are provided on the column longitudinal reinforcement (4) in the reinforced concrete beam (3).

6. The connection node between the strong beam and weak column type transfer beam and the steel concrete column according to claim 1 is characterized in that: A steel mesh (6) is provided at the upper end of the reinforced concrete column (1), and the upper end of the steel mesh (6) extends into the reinforced concrete beam (3).

7. The connection node between the strong beam and weak column type transfer beam and the steel concrete column according to claim 1 is characterized in that: The continuous composite rectangular spiral hoop (5) comprises an outer spiral hoop (51), an inner spiral hoop (52) and a single-limb hoop (11), wherein the outer spiral hoop (51) is arranged on the outer side of the column longitudinal reinforcement (4), the inner spiral hoop (52) is arranged on the inner side of the column longitudinal reinforcement (4), and the single-limb hoop (11) is arranged on two column longitudinal reinforcements (4) at a right angle.

8. The connection node between a strong beam and weak column type transfer beam and a steel-concrete column according to claim 1 or 2, characterized in that: A mortar layer (10) is provided on the surface of the reinforced concrete column (1).

9. The connection node between a strong beam and weak column type transfer beam and a steel-concrete column according to claim 1, characterized in that: The cross section of the first steel section (2) is a cross-shaped structure, and flange plates are provided on the ribs of the first steel section (2).

10. The design method of the connection node between the strong beam and weak column type transfer beam and the steel concrete column is characterized by: The following steps are involved: (1) Calculate the longitudinal reinforcement and steel cross-section of steel-reinforced concrete columns according to the current specifications, but do not adjust the column top bending moment value for the seismic action combination according to relevant regulations. If the column longitudinal reinforcement and steel cross-section obtained are already convenient for the construction of transfer beams and column nodes and for the placement of continuous composite rectangular spiral hoops, the column longitudinal reinforcement and steel cross-section are taken as above and the following step 2 is skipped. (2) The longitudinal reinforcement and steel section of the steel-concrete column are calculated according to the provisions of the current specifications, but the column top bending moment value of the seismic action combination is not adjusted according to the relevant provisions. The column longitudinal reinforcement and steel section obtained are still too many or too large, which is not convenient for the construction of the conversion beam and column node and the placement of the continuous composite rectangular spiral hoop. The column longitudinal reinforcement and steel section are calculated according to the standard value of the effect of the load and seismic action combination, that is, formula (1), and the column top bending moment value of the seismic action combination is not adjusted according to the relevant provisions; S GE +g Eh S Ehk +g Ev S Evk +ψ w c w S wk ≤R (1) Where: S GE is the effect of the representative value of gravity load; S Ehk 、S Evk Divided into the effects of horizontal and vertical earthquake action standard values; S wk is the effect of the standard value of wind load; ψ w is the combined value coefficient of wind load; γ Eh , γ Ev , γ w are the partial factors of horizontal earthquake action, vertical earthquake action and wind load respectively; R is the design value of the resistance of structural components; γ Eh , γ Ev , γ w , ψ w All values ​​are taken according to the current specifications, but when greater than 1.0, they are taken as 1.0; (3) The internal stirrups of reinforced concrete columns are calculated according to the current specifications. The internal stirrups of the columns are in the form of continuous composite rectangular spiral stirrups with excellent mechanical properties; (4) For stirrups in reinforced concrete beam and reinforced concrete column nodes: When the reinforced concrete beam is not provided with a second steel section, a continuous composite rectangular spiral stirrup is used; when the reinforced concrete beam is provided with a second steel section, the usual composite stirrup is used due to the obstruction of the steel section in the beam.

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