A rigid connection joint between a steel beam or steel-concrete composite beam and a concrete column and its design method

Abstract

This invention relates to the technical field of building technology, and discloses a rigid connection node between a steel beam or steel-concrete composite beam and a concrete column, and its design method, comprising the following steps: S1, determining the size of the internal cross stiffening plate based on the cross-sectional dimensions of the four steel structural beams; S2, determining the arrangement and cross-sectional dimensions of the circumferential steel beams; S3, calculating the width and height of the end plate in reverse according to the local compressive bearing capacity based on the combined bending moment of the four steel structural beams; S4, calculating the number of shear bolts. This invention does not affect the column reinforcement arrangement and has almost no impact on the arrangement of the column longitudinal reinforcement and column stirrups within the concrete column; the concrete pouring quality in the core area of ​​this node is reliable, the vertical pouring channel of the concrete column is completely unaffected, vibration leaves no dead corners, construction is convenient, and construction quality is controllable; this node has high overall stiffness, the stress in the four directions tends to be even, and the overall deformation of this node is small.

Description

Technical Field

[0001] This invention relates to the technical field of building technology, and in particular to a rigid connection joint between a steel beam or steel-concrete composite beam and a concrete column and its design method. Background Technology

[0002] In architectural design, large-span spaces (span exceeding 18m) are frequently required. For large-span spaces between 20m and 30m, steel beams are generally used to meet the building's clear height requirements. Long cantilever beams or transfer beams often require steel beams or steel-concrete composite beams to reduce beam height, minimize reinforcement, and facilitate concrete pouring. In these cases, the construction of the rigid connection between the steel beam or steel-concrete composite beam and the concrete column is crucial for ensuring the load-bearing capacity of the steel beam or steel-concrete composite beam and the overall structural load-bearing system.

[0003] Currently, the rigid connection between steel beams and concrete columns mainly adopts the following three methods: 1. Direct embedding: Before pouring the concrete column, the steel beam is inserted into the concrete column and fixed, and the longitudinal reinforcement and stirrups of the column are tied before pouring the concrete column; 2. Pre-embedded steel type: Before pouring the concrete, steel is pre-embedded in the middle of the concrete column, and steel brackets are reserved on the side of the steel. The longitudinal reinforcement and stirrups of the column are tied before pouring the concrete column. The steel beam and steel bracket are connected by equal-strength welding or equal-strength bolts. The cross-sectional shape of the pre-embedded steel can be adjusted to I-shaped, box-shaped, circular, cross-shaped, etc., depending on the cross-sectional shape of the concrete column. This method is also the most widely used at present; 3. Anchor type: Before pouring the concrete column, the anchor (anchor bar, anchor plate) is fixed in the concrete column, and the longitudinal reinforcement and stirrups of the column are tied before pouring the concrete column.

[0004] In the direct-embedded rigid connection between steel beams and concrete columns, the longitudinal reinforcement of the column within the width of the steel beam in the joint area is interrupted, and the stirrups of the column within the height of the steel beam in the joint area are interrupted. Furthermore, during the pouring and vibration of concrete, the presence of the steel beam makes it difficult to vibrate the concrete under the steel beam, making it difficult to compact and prone to hollow areas, which affects the structural safety.

[0005] The pre-embedded steel rigid connection between steel beams and concrete columns also has the three disadvantages mentioned above of the direct-buried rigid connection due to the pre-embedded steel and the four-sided steel brackets in the column. In addition, due to the presence of the pre-embedded steel, the amount of steel used in this method is higher than that of the direct-buried type, and the amount of welding is also larger.

[0006] The anchored rigid connection between steel beams and concrete columns requires a dense number of anchor bars to achieve rigid connection at both ends of the beam, making it difficult to pour the concrete column and install and fix it in the frame column. This type of connection is less stiff than directly buried or pre-embedded steel connections; it is a semi-rigid connection. Semi-rigid connections are difficult to simulate realistically during analysis, and the analysis results are hard to judge, making it impossible to determine the true stiffness and affecting load-bearing safety.

[0007] To address the shortcomings of existing technologies, such as significantly affecting the placement of column reinforcement (longitudinal bars + stirrups) within the joint area, making concrete pouring and vibration difficult in the core area of ​​the joint, and easily leading to insufficient concrete strength and affecting structural safety, a construction-friendly solution is proposed while ensuring that the amount of steel used in the joint does not increase and that the overall stiffness of the joint is good. Summary of the Invention

[0008] The purpose of this invention is to overcome the shortcomings of the prior art and provide a rigid connection node between a steel beam or steel-concrete composite beam and a concrete column.

[0009] The present invention also provides a design method for a rigid connection between a steel beam or a steel-concrete composite beam and a concrete column.

[0010] The objective of this invention is achieved through the following technical solution: A rigid connection node between a steel beam or steel-concrete composite beam and a concrete column includes a concrete column, an internally inserted cross stiffening plate, a circumferential steel beam, and a steel structural beam. The central axis of the internally inserted cross stiffening plate overlaps with the central axis of the concrete column. The second cross-shaped stiffening plate of the internally inserted cross stiffening plate is located inside the concrete column, and the first cross-shaped stiffening plate of the internally inserted cross stiffening plate protrudes from the outer periphery of the concrete column. The first cross-shaped stiffening plate is connected to the steel structural beam by shear bolts. The steel structural beam abuts against the concrete column. Two adjacent steel structural beams are obliquely connected by the circumferential steel beam. The circumferential steel beam is connected end to end to form a steel ring, and the concrete column passes through the steel ring.

[0011] A preferred embodiment includes an internal cross-shaped stiffening plate comprising a first cross-shaped stiffening plate, a second cross-shaped stiffening plate, and shear studs. The shear studs are distributed on the surfaces of the first and second cross-shaped stiffening plates. The central axis of the first and second cross-shaped stiffening plates overlaps. The bottom of the first cross-shaped stiffening plate is connected to the top of the second cross-shaped stiffening plate. The width of the first cross-shaped stiffening plate is greater than the width of the second cross-shaped stiffening plate. The first cross-shaped stiffening plate has stirrup through-holes and bolt through-holes. The stirrup through-holes are located outside the shear studs, and the bolt through-holes are located outside the stirrup through-holes. The column stirrups within the concrete column pass through the stirrup through-holes. The shear studs and the second cross-shaped stiffening plate are located inside the concrete column, and the shear bolts are installed in the bolt through-holes.

[0012] A better option is that the width of the first cross-shaped stiffening plate is D + 190 * 2 + 2 * tf m The height of the first cross-shaped stiffening plate is H. m -320, the thickness of the first cross-shaped stiffening plate is t m+10, where D is the diameter of the concrete column, and tf m H represents the flange thickness of the circumferential steel beam. m The t represents the web height of the steel structure beam. m This refers to the web thickness of the steel structure beam.

[0013] A better option is that the width of the second cross-shaped stiffening plate is D-200*2, and the thickness of the second cross-shaped stiffening plate is t. m +10, where D is the diameter of the concrete column, and t m This refers to the web thickness of the steel structure beam.

[0014] A better option also includes end plates, through which the steel structure beam abuts against the concrete column.

[0015] A design method for a rigid connection between a steel beam or steel-concrete composite beam and a concrete column includes the following steps:

[0016] S1. Determine the dimensions of the internal cross stiffening plate based on the cross-sectional dimensions of the four steel structural beams;

[0017] S2. Determine the arrangement and cross-sectional dimensions of the circumferential steel beams;

[0018] S3. Based on the combined bending moment of the four steel structural beams, the width and height of the end plate are calculated in reverse according to the local compressive bearing capacity.

[0019] S4. Calculate the number of shear bolts.

[0020] A better option is to calculate the second cross-shaped stiffening plate in step S1, which includes the following steps:

[0021] S101. Determine the shear bearing capacity R of the shear stud based on its type. p ,

[0022]

[0023] In the formula, A s E represents the cross-sectional area of ​​the shear stud shank. c f is the elastic modulus of concrete. c denoted as axial compressive strength of concrete, r is the ratio of minimum tensile strength to yield strength of shear stud material, and f is the design value of tensile strength of shear stud.

[0024] S102. Based on the tensile bearing capacity of the second cross-shaped stiffening plate, calculate the required number of shear studs n, and then calculate the arrangement length of the shear studs by considering their spacing. The calculation formula is as follows:

[0025]

[0026] Wherein, D is the diameter of the concrete column, and t m This refers to the web thickness of the steel structure beam.

[0027] A better option, step S3 includes the following steps:

[0028] S301. Based on the structural model of the node, extract the internal forces of the four steel beams of the node under various working conditions, and select the control working condition combination internal forces of the four steel beams according to the "General Specification for Engineering Structures".

[0029] S302. Based on the combined internal force analysis of the control conditions in step S301, the combined bending moment of the four steel structure beams is obtained. According to the force balance condition, the width and height of the end plate are calculated using the formula. The four steel structure beams include the first I-beam, the second I-beam, the third I-beam, and the fourth I-beam.

[0030] A better option, step S302 includes the following steps:

[0031] S3021. When M1, M2, M3 and M4 are negative bending moments, and |M1|>|M2|>|M3|>|M4|, calculate the width and height of the end plate using formula (1). Formula (1) is:

[0032]

[0033] Where M1 is the combined bending moment of the first I-beam, M2 is the combined bending moment of the second I-beam, M3 is the combined bending moment of the third I-beam, M4 is the combined bending moment of the fourth I-beam, α1 is a coefficient, and f c Here, H represents the design value of the axial compressive strength of the concrete. a1, a2, a3, and a4 are the widths of the end plates corresponding to the first, second, third, and fourth I-beams, respectively; b1, b2, b3, and b4 are the heights of the end plates corresponding to the first, second, third, and fourth I-beams, respectively. m This refers to the cross-sectional height of the circumferential steel beam;

[0034] S3022. When M1, M2, and M3 are all negative bending moments and M4 is a positive bending moment, and |M1|>|M2|>|M3|, the width and height of the end plate are calculated using formula (2). Formula (2) is:

[0035]

[0036] S3023. When M1, M2, and M3 are all negative bending moments and M4 is a positive bending moment, and |M1|>|M3|>|M2|, the width and height of the end plate are calculated using formula (3). Formula (3) is:

[0037]

[0038] S3024. When M1 and M3 are negative bending moments, and M2 and M4 are positive bending moments, the width and height of the end plate are calculated using formula (4). Formula (4) is:

[0039]

[0040] A better option is to use the following formula to calculate the number of shear bolts in step S4:

[0041]

[0042] Where N1, N2, N3, and N4 represent the number of shear bolts corresponding to the first, second, third, and fourth I-beams, respectively. v H1, H2, H3, and H4 represent the shear strength of the steel; H1, H2, H3, and H4 represent the beam heights of the first, second, third, and fourth I-beams, respectively; t1, t2, t3, and t4 represent the web thicknesses of the first, second, third, and fourth I-beams, respectively. This indicates the design value of the shear bearing capacity of the shear bolt.

[0043] The present invention has the following advantages and beneficial effects compared with the prior art:

[0044] This invention provides a rigid connection joint and design method between a steel beam or steel-concrete composite beam and a concrete column. This method does not affect the arrangement of the column reinforcement and has almost no impact on the arrangement of the longitudinal reinforcement and stirrups within the concrete column. The concrete pouring quality in the core area of ​​this joint is reliable, the vertical pouring channel of the concrete column is completely unaffected, vibration is thorough, construction is convenient, and construction quality is controllable. This joint has high overall rigidity, the stress in the four directions tends to be even, and the overall deformation of the joint is small. Attached Figure Description

[0045] Figure 1 This is a schematic diagram of a rigid connection node between a steel beam or steel-concrete composite beam and a concrete column according to the present invention.

[0046] Figure 2 This is an exploded view of a rigid connection node between a steel beam or steel-concrete composite beam and a concrete column according to the present invention.

[0047] Figure 3This is an exploded view of the circumferential steel beam, the inclined stiffening plate, and the steel structure beam at the rigid connection node between a steel beam or steel-concrete composite beam and a concrete column according to the present invention.

[0048] Figure 4 This is a front view of an internally inserted cross stiffening plate for a rigid connection between a steel beam or steel-concrete composite beam and a concrete column according to the present invention.

[0049] Figure 5 This is a top view of a rigid connection node between a steel beam or steel-concrete composite beam and a concrete column according to the present invention.

[0050] Figure 6 yes Figure 5 Sectional view at A1;

[0051] Figure 7 yes Figure 5 Sectional view at point A2;

[0052] Figure 8 yes Figure 5 Sectional view at A3;

[0053] Figure 9 yes Figure 5 Sectional view at A4;

[0054] Figure 10 This invention provides a simplified diagram of the stress distribution at a rigid connection between a steel beam or steel-concrete composite beam and a concrete column under vertical load.

[0055] Figure 11 An invention provides a stress flow diagram of a rigid connection between a steel beam or steel-concrete composite beam and a concrete column under vertical load.

[0056] Figure 12 An invention provides a stress flow diagram of a rigid connection between a steel beam or steel-concrete composite beam and a concrete column under vertical load.

[0057] Figure 13 This invention provides a simplified force diagram of a rigid connection between a steel beam or steel-concrete composite beam and a concrete column under horizontal load.

[0058] Figure 14 Invent a stress flow diagram of a rigid joint between a steel beam or steel-concrete composite beam and a concrete column under horizontal load.

[0059] Figure 15 Invent a stress flow diagram of a rigid joint between a steel beam or steel-concrete composite beam and a concrete column under horizontal load.

[0060] Figure 16 A schematic diagram of the combined bending moment in step S3021 of the invention of a design method for a rigid connection between a steel beam or steel-concrete composite beam and a concrete column.

[0061] Figure 17 A schematic diagram of the combined bending moment in steps S3022 and S3023 of the invention of a design method for a rigid connection between a steel beam or steel-concrete composite beam and a concrete column.

[0062] Figure 18 A schematic diagram of the combined bending moment in step S3024 of the invention of a design method for a rigid connection between a steel beam or steel-concrete composite beam and a concrete column.

[0063] Figure 19 A flowchart illustrating a design method for a rigid connection between a steel beam or steel-concrete composite beam and a concrete column.

[0064] The components in the attached diagram are labeled as follows: 1-Concrete column; 101-Column longitudinal reinforcement; 102-Column stirrups; 2-Circumferential steel beam; 3-Diagonal stiffening plate; 4-Steel structural beam; 401-First I-beam; 402-Second I-beam; 403-Third I-beam; 404-Fourth I-beam; 5-Internal cross stiffening plate; 51-First cross stiffening plate; 511-Stirrup perforation; 512-Bolt perforation; 52-Second cross stiffening plate; 53-Shear stud; 6-End plate; 7-Shear bolt. Detailed Implementation

[0065] The invention's objective will be further described in detail below with reference to the accompanying drawings and specific embodiments. The embodiments cannot be described in detail here, but the implementation of the invention is not limited to the following embodiments.

[0066] like Figure 1-9As shown, a rigid connection node between a steel beam or steel-concrete composite beam and a concrete column in this embodiment includes a concrete column 1, an internally inserted cross stiffening plate 5, four circumferential steel beams 2, eight diagonal stiffening plates 3, and four steel structural beams 4. The central axis of the internally inserted cross stiffening plate 5 overlaps with the central axis of the concrete column 1. The second cross-shaped stiffening plate 52 of the internally inserted cross stiffening plate 5 is enclosed inside the concrete column 1, and the first cross-shaped stiffening plate 51 of the internally inserted cross stiffening plate 5 protrudes from the outer circumference of the concrete column 1. The four protruding parts of the first cross-shaped stiffening plate 51 are respectively connected to the four steel structural beams 4 by shear bolts 7. The flanges of the four steel structural beams 4 are provided with end plates 6, which abut against the outer circumferential surface of the concrete column 1. The eight diagonal stiffening plates 3 are set at 45° relative to the X-axis or Y-axis, and the two ends of each diagonal stiffening plate 3 are respectively cross-connected to two adjacent steel structural beams 4. Four circumferential steel beams 2 are positioned at 45° relative to the X-axis or Y-axis. These four beams are welded to the upper sides of four steel structural beams 4, with the upper beams connected end-to-end. Similarly, the four circumferential steel beams 2 are welded to the lower sides of four steel structural beams 4, forming a steel ring. Eight diagonal stiffening plates 3 are welded to the diagonal connections between the webs of the four steel structural beams 4 and the four circumferential steel beams 2. Two diagonal stiffening plates 3 are welded to both sides of the web of each steel structural beam 4. The upper end of the concrete column 1 is located within the upper steel ring, and the lower end is located within the lower steel ring.

[0067] The concrete column 1 is cylindrical and serves to bear vertical forces, thus fulfilling its load-bearing function. Internal cross-shaped stiffening plates 5 transfer bending moments in all directions to the longitudinal reinforcement 101 of the concrete column 1. Circumferential steel beams 2 balance the forces and stresses on the various I-beams 4, achieving bending moment balance outside the concrete column 1. The steel structure beams 4 are I-beams, including a first I-beam 401, a second I-beam 402, a third I-beam 403, and a fourth I-beam 404, and serve as load-bearing components.

[0068] like Figure 4As shown, the internal cross-shaped stiffening plate 5 includes a first cross-shaped stiffening plate 51, a second cross-shaped stiffening plate 52, and multiple shear studs 53. The shear studs 53 are evenly distributed on the surface of the second cross-shaped stiffening plate 52, and the central axis of the first cross-shaped stiffening plate 51 overlaps with the central axis of the second cross-shaped stiffening plate 52. The bottom of the first cross-shaped stiffening plate 51 is connected to the top of the second cross-shaped stiffening plate 51. Each of the four protrusions of the first cross-shaped stiffening plate 51 has a row of stirrup through holes 511, with a spacing of 100mm between adjacent stirrup through holes 511. The diameter of the stirrup through holes 511 is the diameter of the column stirrup 102 + 2mm, to facilitate the binding of the column stirrup 102. Two rows of bolt through holes 512 are provided outside this row of stirrup through holes 511. All four protrusions of the first cross-shaped stiffening plate 51 protrude from the outer circumference of the concrete column 1. Shear bolts 7 pass through two rows of bolt holes 512 in the first cross-shaped stiffening plate 51 and are connected to the steel beam 4. The second cross-shaped stiffening plate 52 and shear studs are encased inside the concrete column 1.

[0069] The width of the first cross-shaped stiffening plate 51 is D + 190 * 2 + 2 * tf m Where 190mm is calculated based on the number of bolt rows and spacing, D is the diameter of concrete column 1, and tf m The flange thickness is H of the circumferential steel beam 2. The height of the first cruciform stiffening plate 51 is H. m -320, H m The web height of steel beam 4 is given. The thickness of the first cross-shaped stiffening plate 51 is given by t. m +10, t m The thickness of the web of steel beam 4 is given. The width of the second cross-shaped stiffening plate is D-200*2. The height h2 of the second cross-shaped stiffening plate is calculated based on the tensile bearing capacity of the section of the second cross-shaped stiffening plate to determine the required number of shear studs 53. The length of the second cross-shaped stiffening plate is then calculated based on the number of shear studs 53. The thickness of both the first cross-shaped stiffening plate 51 and the second cross-shaped stiffening plate 52 is t. m +10.

[0070] A construction method for a rigid connection between a steel beam or steel-concrete composite beam and a concrete column:

[0071] Before pouring the concrete column 1, an inner cross-shaped stiffening plate 5 is inserted into the cylindrical mold of the concrete column 1. Two rows of shear studs 53 are installed on the second cross-shaped stiffening plate 52 of the inner cross-shaped stiffening plate 5. The distance between two adjacent shear studs 53 is 150mm, and the size of the shear studs 53 is φ19×90mm. The column stirrups 102 are passed through the stirrup through holes 511 of the four protrusions of the first cross-shaped stiffening plate 51 of the inner cross-shaped stiffening plate 5, and the column stirrups 102 are tied to the column longitudinal reinforcement 101. Then, concrete is poured into the cylindrical mold. After the concrete solidifies, a concrete column 1 with the protrusions of the first cross-shaped stiffening plate 51 is obtained.

[0072] Then, upper end plates 6 are installed on the flanges at the ends of the first I-beam 401, the second I-beam 402, the third I-beam 403, and the fourth I-beam 404, and the end plates 6 are pressed tightly against the outer periphery of the concrete column 1. The first I-beam 401, the second I-beam 402, the third I-beam 403, and the fourth I-beam 404 are respectively fixedly connected to the four protrusions of the internal cross stiffening plate 5 by shear bolts 7. The number of shear bolts 7 at the connection between each steel structure beam 4 and the protrusion, N, is greater than or equal to the shear bearing capacity of the web of the steel structure beam 4 / the shear bearing capacity of one shear bolt 7. The thickness of the end plate 6 is the web thickness of the corresponding steel structure beam 4, and the height and length of the end plate 6 can be determined by calculating the local compressive bearing capacity.

[0073] A circumferential steel beam 2 is respectively installed between the first I-beam 401 and the third I-beam 403, between the first I-beam 401 and the fourth I-beam 404, between the second I-beam 402 and the third I-beam 403, and between the second I-beam 402 and the fourth I-beam 404. The angle between the circumferential steel beam 2 and the X-axis or Y-axis ranges from 30° to 60°, and 45° is selected in this embodiment. The cross-sectional dimension of the circumferential steel beam 2 is H. m ×b m ×t m ×tf m H m For height, b m For the flange width, t m For web thickness, tf m H represents the flange thickness. m b m t m and TF m The values ​​are the larger of the corresponding cross-sectional dimensions of the four steel beams, i.e., H. m =max{H1, H2, H3, H4}, b m =max{b1, b2, b3, b4}, t m =max{t1, t2, t3, t4}, tfm =max{tf1, tf2, tf3, tf4}. The four circumferential steel beams 2 are welded to the first I-beam 401, the second I-beam 402, the third I-beam 403, and the fourth I-beam 404, respectively. Since the heights of the first I-beam 401, the second I-beam 402, the third I-beam 403, and the fourth I-beam 404 may be inconsistent, to ensure the continuity of force transmission in the circumferential steel beams 2, the first I-beam 401, the second I-beam 402, the third I-beam 403, and the fourth I-beam 404 are sloped at a 1:3 gradient in the height direction of the circumferential steel beams 2 at the end closest to the concrete column 1.

[0074] Explanation of the stress mechanism of a rigid connection between a steel beam or steel-concrete composite beam and a concrete column:

[0075] Under vertical load, the stress state at this node is as follows: Figure 10-12 As shown. Under negative bending moment, the upper flange of steel beam 4 is under tension, and the lower flange is under compression. The upper flange of steel beam 4 achieves tension balance through the flange of the upper circumferential steel beam 2 connected to it, and the lower flange of steel beam 4, which is under compression, achieves axial balance through the flange of the lower circumferential steel beam 2 connected to it. Generally, under the premise that the bending moments of each steel beam 4 are equal, the bending moment self-balancing is achieved outside the concrete column 1. The concrete column 1 does not bear the bending moment, but only the vertical force, which can significantly reduce the column cross-section size and reinforcement. However, in actual engineering, due to the inconsistent bending moments of each steel beam 4, the unbalanced bending moment is transmitted to the concrete column 1 through two paths: 1. Through the compressed end plate 6 to the concrete column 1; 2. Through the internally inserted cross stiffening plate 5 to the concrete column 1, which is absorbed by the longitudinal reinforcement 101 of the concrete column 1. Under shear force, the webs of the four steel beams 4 are directly transferred to the inner cross stiffening plates 5 through shear bolts 7, and the inner cross stiffening plates 5 are then transferred to the concrete columns 1 through shear studs 53.

[0076] Under horizontal load, the stress state at this node is as follows: Figure 13-15 As shown. Under negative bending moment, the upper flanges of the first I-beam 401 and the third I-beam 403 are under tension, and the lower flanges are under compression. Under positive bending moment, the upper flanges of the second I-beam 402 and the fourth I-beam 404 are under compression, and the lower flanges are under tension. The tension and compression of the upper and lower flanges of the steel beams 4 cannot be balanced by the circumferential steel beams 2, but can be transmitted to the concrete columns 1 through two paths: 1. Through the compressed end plate 6; 2. Through the internally inserted cross stiffening plate 5, and absorbed by the longitudinal reinforcement 101 in the concrete column 1. According to the stiffness distribution principle, the first force transmission path accounts for more than 85% and is the main force transmission path.

[0077] Considering the significant difference in force transmission mechanisms under vertical and horizontal loads at this node, and that the force transmission mechanism under vertical loads is more favorable to the node, the application of this node can be divided into two cases: 1. When the vertical load is dominant and the horizontal load has no controlling effect, the end plate 6 at the flange of steel beam 4 can be eliminated. Appropriately increasing the thickness of the inner cross stiffening plate 5 can also meet the node's bearing capacity and deformation requirements, and can reduce the column cross section; 2. When there is an unbalanced bending moment under vertical load and the horizontal load is controlling, the end plate 6 at the flange of steel beam 4 must be retained to absorb the unbalanced bending moment and meet the node's bearing capacity and deformation requirements. This node is also applicable to the connection node between concrete column 1 and steel-concrete composite beam.

[0078] In addition, this node is also applicable to foundations or flat slabs connected to concrete columns 1. This node can improve the shear and punching shear resistance of the node by inserting cross stiffening plates 5 and circumferential steel beams 2, improve the brittle punching shear failure mode, and reduce the thickness of the column base or column cap.

[0079] like Figure 19 As shown, a design method for a rigid connection between a steel beam or steel-concrete composite beam and a concrete column includes the following steps:

[0080] S1. Determine the dimensions of the inner cross stiffening plate 5 based on the cross-sectional dimensions of the four steel structure beams 4;

[0081] The calculation method for the second cross-shaped stiffening plate 52 of the intercalated cross stiffening plate 5 in step S1 includes the following steps:

[0082] S101. Determine the shear bearing capacity R of shear stud 53 according to its model. p ,

[0083]

[0084] In the formula, A s E is the cross-sectional area of ​​the shear stud 53. c f is the elastic modulus of concrete. c denoted as axial compressive strength of concrete, r is the ratio of minimum tensile strength to yield strength of shear stud 53, and f is the design value of tensile strength of shear stud 53.

[0085] S102. Based on the tensile bearing capacity of the second cross-shaped stiffening plate 52, calculate the required number n of shear studs 53. Then, using the spacing of the shear studs 53 (150x150mm), calculate the arrangement length of the shear studs 53. The calculation formula is as follows:

[0086]

[0087] Where D is the diameter of concrete column 1, tm The thickness of the web of steel beam 4 is given.

[0088] S2. Determine the arrangement and cross-sectional dimensions of the circumferential steel beam 2, as described above;

[0089] S3. Based on the combined bending moment of the four steel beams 4, the width and height of the end plate 6 are calculated in reverse according to the local compressive bearing capacity; step S3 includes the following steps:

[0090] S301. Based on the structural model of the node, extract the internal forces (including shear force V and bending moment M) of the four steel beams 4 under various working conditions of this node, and select the control working condition combination internal forces (V1~V4, M1~M4) of the four steel beams 4 according to the "General Specification for Engineering Structures".

[0091] S302. By analyzing the combined bending moments of the four steel structural beams 4 (including positive or negative bending moments; when the lower side of the member section is under tension, it is called a positive bending moment; when the upper side of the member section is under tension, it is called a negative bending moment), and based on the force equilibrium condition, the width and height of the end plate 6 are calculated using a formula. The four steel structural beams 4 include a first I-beam 401, a second I-beam 402, a third I-beam 403, and a fourth I-beam 404. Step S302 includes the following steps:

[0092] S3021, such as Figure 16 As shown, when M1, M2, M3 and M4 are negative bending moments, and |M1|>|M2|>|M3|>|M4|, the combined bending moment of the first I-beam 401 at this node can be divided into two parts: |M1-M4| and |M4|. Similarly, the combined bending moment of the second I-beam 402 can be divided into two parts: |M2-M4| and |M4|. The combined bending moment of the third I-beam 403 can be divided into two parts: |M3-M4| and |M4|. Under the action of the bending moment of part M4, the bending moments in all directions are equal, and the bending moment self-balancing is achieved in the circumferential steel beam 2 outside the concrete column 1. The concrete column 1 does not bear the bending moment. The difference bending moments |M1-M4|, |M2-M4|, and |M3-M4| are balanced by the compressive force between the end plate 6 and the concrete column 1. The width and height of the end plate 6 are calculated by formula (1). The calculation formula (1) is as follows:

[0093]

[0094] Where M1 is the combined bending moment of the first I-beam 401, M2 is the combined bending moment of the second I-beam 402, M3 is the combined bending moment of the third I-beam 403, M4 is the combined bending moment of the fourth I-beam 404, α1 is a coefficient, taken from Article 6.2.6 of the "Code for Design of Concrete Structures" (GB50010-2010 (2015 Edition)), f c The design value of the axial compressive strength of concrete is taken from Table 4.1.4-1 of the "Code for Design of Concrete Structures" (GB50010-2010 (2015 edition)). a1, a2, a3, and a4 are the widths of the end plates 6 corresponding to the first I-beam 401, the second I-beam 402, the third I-beam 403, and the fourth I-beam 404, respectively. b1, b2, b3, and b4 are the heights of the end plates 6 corresponding to the first I-beam 401, the second I-beam 402, the third I-beam 403, and the fourth I-beam 404, respectively. H m The cross-sectional height of the circumferential steel beam 2;

[0095] S3022, such as Figure 17 As shown, when M1, M2, and M3 are all negative bending moments and M4 is a positive bending moment, and |M1|>|M2|>|M3|, the combined bending moment of the first I-beam 401 at this node can be divided into two parts: |M1-M3| and |M3|. Similarly, the combined bending moment of the second I-beam 402 can be divided into two parts: |M2-M3| and |M3|. The combined bending moment of the fourth I-beam 404 can be divided into two parts: |M4-M3| and |M3|. Under the action of the bending moment of part M3, the bending moments in all directions are equal, and the bending moment self-balancing is achieved in the circumferential steel beam 2 outside the concrete column 1. The concrete column 1 does not bear the bending moment. The difference bending moments |M1-M3|, |M2-M3|, and |M4-M3| are balanced by the compressive force between the end plate 6 and the concrete column 1. The width and height of the end plate 6 are calculated by formula (2). The calculation formula (2) is as follows:

[0096]

[0097] S3023, such as Figure 17As shown, when M1, M2, and M3 are all negative bending moments and M4 is a positive bending moment, and |M1|>|M3|>|M2|, the combined bending moment of the first I-beam 401 at this node can be divided into two parts: |M1-M2| and |M2|. Similarly, the combined bending moment of the third I-beam 403 can be divided into two parts: |M3-M2| and |M2|, and the combined bending moment of the fourth I-beam 404 can be divided into two parts: |C4-M2| and |M2|. Under the action of the bending moment of part M2, the bending moments in all directions are equal, and the bending moment self-balancing is achieved in the circumferential steel beam 2 outside the concrete column 1. The concrete column 1 does not bear the bending moment. The difference bending moments |M1-M2|, |M3-M2|, and |M4-M2| are balanced by the compressive force between the end plate 6 and the concrete column 1. The width and height of the end plate 6 are calculated by formula (3). The calculation formula (3) is as follows:

[0098]

[0099] S3024, such as Figure 18 As shown, when M1 and M3 are negative bending moments, and M2 and M4 are positive bending moments, the bending moments are entirely balanced by the compressive force between the end plate 6 and the concrete column 1. The width and height of the end plate 6 are calculated using formula (4). This formula (4) is:

[0100]

[0101] S4. Calculate the number of shear bolts 7. The formula for calculating the number of shear bolts 7 in step S4 includes:

[0102]

[0103] Wherein, N1, N2, N3, and N4 represent the number of shear bolts 7 corresponding to the first I-beam 401, the second I-beam 402, the third I-beam 403, and the fourth I-beam 404, respectively. v The values ​​represent the shear strength of the steel; H1, H2, H3, and H4 represent the beam heights of the first H-beam 401, the second H-beam 402, the third H-beam 403, and the fourth H-beam 404, respectively; t1, t2, t3, and t4 represent the web thicknesses of the first H-beam 401, the second H-beam 402, the third H-beam 403, and the fourth H-beam 404, respectively. This represents the design value of the shear bearing capacity of shear bolt 7. The calculation formula is consistent with the content of Section 11.4.2 of the "Standard for Design of Steel Structures" (GB 50017-2017).

[0104] The nodes in this embodiment have the following advantages:

[0105] 1) Does not affect the arrangement of column reinforcement

[0106] Since the steel beam 4 at this node only has its web plate in contact with the concrete column 1, and this node only has the first cross-shaped stiffening plate 51 and the second cross-shaped stiffening plate 52, it has no effect on the arrangement of the longitudinal reinforcement 101 in the concrete column 1, but has a slight effect on the column stirrups 102. However, this effect can be eliminated by pre-drilling holes at the corresponding positions of the column stirrups 102 during the previous steel structure node detailing process.

[0107] 2) The concrete pouring quality of the core area of ​​the node is reliable.

[0108] Since this node only has the first and second cross-shaped steel plates, the vertical pouring channel of concrete column 1 is completely unaffected, vibration leaves no dead corners, construction is convenient, and construction quality is controllable.

[0109] 3) The overall stiffness of the nodes is relatively large.

[0110] Due to the presence of the circumferential steel beam 2 outside the concrete column 1, when this node is under stress, the stiffness of the circumferential steel beam 2 makes the stress on this node tend to be even in the four directions, and the overall deformation of this node is small.

[0111] Example 2

[0112] Except for the following technical features, the other technical features in this embodiment are the same as those in Embodiment 1.

[0113] In this embodiment, steel-concrete composite beams are used instead of I-beams for the steel structure beams.

[0114] In this embodiment, the four circumferential steel beams 2 are set at 30° relative to the X-axis or Y-axis.

[0115] Example 3

[0116] Except for the following technical features, the other technical features in this embodiment are the same as those in Embodiment 1.

[0117] In this embodiment, the four circumferential steel beams 2 are set at 60° relative to the X-axis or Y-axis.

[0118] The above-described specific embodiments are preferred embodiments of the present invention and are not intended to limit the present invention. Any other changes or equivalent substitutions made without departing from the technical solution of the present invention are included within the protection scope of the present invention.

Claims

1. A rigid connection between a steel beam or steel-concrete composite beam and a concrete column, characterized in that: The system includes a concrete column, an internally inserted cross-shaped stiffening plate, a circumferential steel beam, and a steel structural beam. The central axis of the internally inserted cross-shaped stiffening plate overlaps with the central axis of the concrete column. The second cross-shaped stiffening plate of the internally inserted cross-shaped stiffening plate is located inside the concrete column, and the first cross-shaped stiffening plate of the internally inserted cross-shaped stiffening plate protrudes from the outer periphery of the concrete column. The first cross-shaped stiffening plate is connected to the steel structural beam by shear bolts. The steel structural beam abuts against the concrete column. Two adjacent steel structural beams are obliquely connected by the circumferential steel beam. The circumferential steel beam is connected end to end to form a steel ring, and the concrete column passes through the steel ring. The internal cross-shaped stiffening plate includes a first cross-shaped stiffening plate, a second cross-shaped stiffening plate, and shear studs. The shear studs are distributed on the surfaces of the first and second cross-shaped stiffening plates. The central axis of the first and second cross-shaped stiffening plates overlaps. The bottom of the first and second cross-shaped stiffening plates is connected to the top of the second cross-shaped stiffening plate. The width of the first and second cross-shaped stiffening plates is greater than the width of the second cross-shaped stiffening plate. The first cross-shaped stiffening plate has stirrup through holes and bolt through holes. The stirrup through holes are located outside the shear studs, and the bolt through holes are located outside the stirrup through holes. The column stirrups in the concrete column pass through the stirrup through holes. The shear studs and the second cross-shaped stiffening plate are located inside the concrete column, and the shear bolts are installed in the bolt through holes.

2. The rigid connection between a steel beam or steel-concrete composite beam and a concrete column according to claim 1, characterized in that: The width of the first cross-shaped stiffening plate is D + 190 * 2 + 2 * tf m The height of the first cross-shaped stiffening plate is H. m -320, the thickness of the first cross-shaped stiffening plate is t m +10, where D is the diameter of the concrete column, and tf m H represents the flange thickness of the circumferential steel beam. m The t represents the web height of the steel structure beam. m This refers to the web thickness of the steel structure beam.

3. The rigid connection between a steel beam or steel-concrete composite beam and a concrete column according to claim 1, characterized in that: The width of the second cross-shaped stiffening plate is D-200*2, and the thickness of the second cross-shaped stiffening plate is t. m +10, where D is the diameter of the concrete column, and t m This refers to the web thickness of the steel structure beam.

4. The rigid connection between a steel beam or steel-concrete composite beam and a concrete column according to claim 1, characterized in that: It also includes end plates, through which the steel structure beam abuts against the concrete column.

5. The design method for a rigid connection between a steel beam or steel-concrete composite beam and a concrete column according to claim 4, characterized in that: Includes the following steps: S1. Determine the dimensions of the internal cross stiffening plate based on the cross-sectional dimensions of the four steel structural beams; S2. Determine the arrangement and cross-sectional dimensions of the circumferential steel beams; S3. Based on the combined bending moment of the four steel structural beams, the width and height of the end plate are calculated in reverse according to the local compressive bearing capacity. S4. Calculate the number of shear bolts; The calculation method for the second cross-shaped stiffening plate in step S1 includes the following steps: S101. Determine the shear bearing capacity R of the shear stud based on its type. p , In the formula, A s E represents the cross-sectional area of ​​the shear stud shank. c f is the elastic modulus of concrete. c denoted as axial compressive strength of concrete, r is the ratio of minimum tensile strength to yield strength of shear stud material, and f is the design value of tensile strength of shear stud. S102. Based on the tensile bearing capacity of the second cross-shaped stiffening plate, calculate the required number of shear studs n, and then calculate the arrangement length of the shear studs by using the spacing of the shear studs. The calculation formula is as follows: Wherein, D is the diameter of the concrete column, and t m This refers to the web thickness of the steel structure beam.

6. The design method for a rigid connection between a steel beam or steel-concrete composite beam and a concrete column according to claim 5, characterized in that: Step S3 includes the following steps: S301. Based on the structural model of the node, extract the internal forces of the four steel beams of the node under various working conditions, and select the control working condition combination internal forces of the four steel beams according to the "General Specification for Engineering Structures". S302. Based on the combined internal force analysis of the control conditions in step S301, the combined bending moment of the four steel structure beams is obtained. According to the force balance condition, the width and height of the end plate are calculated using the formula. The four steel structure beams include the first I-beam, the second I-beam, the third I-beam, and the fourth I-beam.

7. The design method for a rigid connection between a steel beam or steel-concrete composite beam and a concrete column according to claim 6, characterized in that: Step S302 includes the following steps: S3021. When M1, M2, M3 and M4 are negative bending moments, and |M1|>|M2|>|M3|>|M4|, calculate the width and height of the end plate using formula (1). Formula (1) is: Where M1 is the combined bending moment of the first I-beam, M2 is the combined bending moment of the second I-beam, M3 is the combined bending moment of the third I-beam, M4 is the combined bending moment of the fourth I-beam, α1 is a coefficient, and f c Here, H represents the design value of the axial compressive strength of the concrete. a1, a2, a3, and a4 are the widths of the end plates corresponding to the first, second, third, and fourth I-beams, respectively; b1, b2, b3, and b4 are the heights of the end plates corresponding to the first, second, third, and fourth I-beams, respectively. m This refers to the cross-sectional height of the circumferential steel beam; S3022. When M1, M2, and M3 are all negative bending moments and M4 is a positive bending moment, and |M1|>|M2|>|M3|, calculate the width and height of the end plate using formula (2). Formula (2) is: S3023. When M1, M2, and M3 are all negative bending moments and M4 is a positive bending moment, and |M1|>|M3|>|M2|, the width and height of the end plate are calculated using formula (3). Formula (3) is: S3024. When M1 and M3 are negative bending moments, and M2 and M4 are positive bending moments, the width and height of the end plate are calculated using formula (4). Formula (4) is:

8. The design method for a rigid connection between a steel beam or steel-concrete composite beam and a concrete column according to claim 5, characterized in that: The formula for calculating the number of shear bolts in step S4 includes: The four steel structural beams include a first H-beam, a second H-beam, a third H-beam, and a fourth H-beam; N1, N2, N3, and N4 represent the number of shear bolts corresponding to the first, second, third, and fourth H-beams, respectively. v H1, H2, H3, and H4 represent the shear strength of the steel; H1, H2, H3, and H4 represent the beam heights of the first, second, third, and fourth I-beams, respectively; t1, t2, t3, and t4 represent the web thicknesses of the first, second, third, and fourth I-beams, respectively. This indicates the design value of the shear bearing capacity of the shear bolt.

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